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Johanna Maria Catharina BLOM

Professore Associato
Dipartimento di Scienze Biomediche, Metaboliche e Neuroscienze sede ex-Sc. Biomediche


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Pubblicazioni

2023 - ADOLESCENCE AS A CRITICAL TIME-WINDOW FOR NEUROINFLAMMATION IN THE MOUSE: WHY SEX MATTERS [Abstract in Rivista]
Toscano, Ylenia; Benatti, Cristina; Alboni, Silvia; Ciani, Miriam; Rigillo, Giovanna; Tascedda, Fabio; Blom, Johanna Maria Catharina; Brunello, Nicoletta
abstract


2023 - Invertebrates as models of learning and memory: investigating neural and molecular mechanisms [Articolo su rivista]
Rivi, Veronica; Benatti, Cristina; Rigillo, Giovanna; Blom, Johanna M C
abstract

: In this Commentary, we shed light on the use of invertebrates as model organisms for understanding the causal and conserved mechanisms of learning and memory. We provide a condensed chronicle of the contribution offered by mollusks to the studies on how and where the nervous system encodes and stores memory and describe the rich cognitive capabilities of some insect species, including attention and concept learning. We also discuss the use of planarians for investigating the dynamics of memory during brain regeneration and highlight the role of stressful stimuli in forming memories. Furthermore, we focus on the increasing evidence that invertebrates display some forms of emotions, which provides new opportunities for unveiling the neural and molecular mechanisms underlying the complex interaction between stress, emotions and cognition. In doing so, we highlight experimental challenges and suggest future directions that we expect the field to take in the coming years, particularly regarding what we, as humans, need to know for preventing and/or delaying memory loss. This article has an associated ECR Spotlight interview with Veronica Rivi.


2023 - Role of dopamine D3 receptors, dysbindin, and their functional interaction on the expression of key genes for neuroplasticity in the mouse brain [Abstract in Rivista]
Rivi, Veronica; Benatti, Cristina; Blom, Johanna; Pani, Luca; Brunello, Nicoletta; Drago, Filippo; Papaleo, Francesco; Torrisi, Sebastiano; Salomone, Salvatore; Leggio Gian, Marco; Tascedda, Fabio
abstract


2022 - A flavonoid, quercetin, is capable of enhancing long-term memory formation if encountered at different times in the learning, memory formation, and memory recall continuum [Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Blom, J. M.; Tascedda, F.; Lukowiak, K.
abstract

A major extrinsic factor influencing memory and neuro-cognitive performances across taxa is diet. Studies from vertebrates have shown the effects of a flavonoid rich diet on cognitive performance, but the mechanism underlying this action is still poorly understood. A common and abundant flavonoid present in numerous food substances is quercetin (Q). The present study provides the first support for Q-modulated enhancement of cognitive function in an invertebrate model, the pond snail Lymnaea stagnalis, after an operant conditioning procedure. We found that when snails were exposed to Q 3 h before or after a single 0.5 h training session, which typically results in memory lasting ~ 3 h, they formed a long-term memory (LTM) lasting for at least 24 h. Additionally, we assessed the effects of the combined presentation of a single reinforcing stimulus (at 24 h post-training or 24 h before training) and Q-exposure on both LTM formation and reconsolidation. That is, when applied within 3 h of critical periods of memory, Q regulates four different phases: (1) acquisition (i.e., a learning event), (2) consolidation processes after acquisition, (3) memory recall, and (4) memory reconsolidation. In all these phases Q-exposure enhanced LTM persistence.


2022 - Aspirin reverts lipopolysaccharide-induced learning and memory impairment: first evidence from an invertebrate model system [Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Tascedda, F.; Blom, J. M. C.; Lukowiak, K.
abstract

By employing a reductionistic (but not simplistic) approach using an established invertebrate model system, the pond snail Lymnaea stagnalis, we investigated whether (1) lipopolysaccharide (LPS)-induced inflammation would cause a sickness state and impair cognitive function, and-if so-(2) would aspirin (acetylsalicylic acid-ASA) restore the impaired cognition. To test our hypotheses, we first determined if the injection of 25 mg (6.25 μg/mL) of Escherichia coli-derived LPS serotype O127:B8 altered homeostatic behavior, aerial respiration, and then determined if LPS altered memory formation when this behavior was operantly conditioned. Next, we determined if ASA altered the LPS-induced changes in both aerial respiration and cognitive functions. LPS induced a sickness state that increased aerial respiration and altered the ability of snails to form or recall long-term memory. ASA reverted the LPS-induced sickness state and thus allowed long-term memory both to be formed and recalled. We confirmed our hypotheses and provided the first evidence in an invertebrate model system that an injection of LPS results in a sickness state that obstructs learning and memory, and this impairment can be prevented by a non-steroidal anti-inflammatory.


2022 - Comprehensive Pain Management Using Opioids for Children and Adolescents: Still a Wild Goose to Chase? [Articolo su rivista]
Blom, J. M. C.; Benatti, C.
abstract


2022 - Deciphering the central immunomodulatory effects of a vortioxetine pretreatment on the LPS-induced inflammatory cascade [Abstract in Atti di Convegno]
Ciani, M.; Toscano, Y.; Benatti, C.; Blom, J. M. C.; Tascedda, F.; Alboni, S.; Brunello, N.
abstract


2022 - Fluoride affects memory by altering the transcriptional activity in the central nervous system of Lymnaea stagnalis [Articolo su rivista]
Rivi, V.; Batabyal, A.; Wiley, B.; Benatti, C.; Tascedda, F.; Blom, J. M. C.; Lukowiak, K.
abstract

Fluoride (F-), has been found to affect learning and memory in several species. In this study, we exposed an F--naïve, inbred strain of Lymnaea stagnalis to a concentration of F- similar to that naturally occurring in wild ponds. We found that the exposure to F- before the configural learning procedure obstructs the memory formation and blocks the configural learning-induced upregulation of CREB1, GRIN1, and HSP70 in snails' central ring ganglia. Along with altering the mRNA levels of these key genes for memory formation, a single acute F- exposure also upregulates Cytochrome c Oxidase, a major regulatory enzyme of the electron transport chain, which plays direct or indirect roles in reactive oxygen species production. As the central nervous system is sensitive to oxidative stress and consistent with previous studies from mammals, our results suggest a potential role of oxidative stress in memory impairment. To our knowledge, this is the first study investigating the neuronal mechanism of memory impairment in an invertebrate species that is exposed to natural F- levels.


2022 - Identification and characterization of the kynurenine pathway in the pond snail Lymnaea stagnalis [Articolo su rivista]
Benatti, Cristina; Rivi, Veronica; Alboni, Silvia; Grilli, Andrea; Castellano, Sara; Pani, Luca; Brunello, Nicoletta; Blom, Johanna Maria Catharina; Bicciato, Silvio; Tascedda, Fabio
abstract


2022 - Identifying child maltreatment in the 0-3 age group: A screening protocol for childcare professionals developed within the ECLIPS project. [Abstract in Atti di Convegno]
Blom, J. M. C.; Benassi, Erika
abstract


2022 - Nature versus nurture in heat stress induced learning between inbred and outbred populations of Lymnaea stagnalis [Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Blom, J. M.; Lukowiak, K.
abstract

Changing environmental conditions often lead to microevolution of traits that are adaptive under the current selection pressure. Currently, one of the major selection pressures is the rise in temperatures globally that has a severe impact on the behavioral ecology of animals. However, the role of thermal stress on neuronal plasticity and memory formation is not well understood. Thermal tolerance and sensitivity to heat stress show variation across populations of the same species experiencing different thermal regimes. We used two populations of the pond snail Lymnaea stagnalis: one lab-bred W-snails and the other wild Delta snails to test heat shock induced learning and memory formation for the Garcia effect learning paradigm. In Garcia effect, a single pairing of a heat stressor (30 °C for 1h) with a novel taste results in a taste-specific negative hedonic shift lasting 24h as long-term memory (LTM) in lab bred W-snails. In this study we used a repeated heat stress procedure to test for increased or decreased sensitivity to the heat before testing for the Garcia effect. We found that lab-bred W-snails show increased sensitivity to heat stress after repeated heat exposure for 7days, leading to enhanced LTM for Garcia effect with only 15min of heat exposure instead of standard 1h. Surprisingly, the freshly collected wild snails do not show Garcia effect. Additionally, F1 generation of wild snails raised and maintained under laboratory conditions still retain their heat stress tolerance similar to their parents and do not show a Garcia effect under standard learning paradigm or even after repeated heat stressor. Thus, we found a differential effect of heat stress on memory formation in wild and lab bred snails. Most interestingly we also show that local environmental (temperature) conditions for one generation is not enough to alter thermal sensitivity in a wild population of L. stagnalis.


2022 - Recommendations for the surveillance of mental health problems in childhood, adolescent, and young adult cancer survivors: a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group [Articolo su rivista]
Marchak, J. G.; Christen, S.; Mulder, R. L.; Baust, K.; Blom, J. M. C.; Brinkman, T. M.; Elens, I.; Harju, E.; Kadan-Lottick, N. S.; Khor, J. W. T.; Lemiere, J.; Recklitis, C. J.; Wakefield, C. E.; Wiener, L.; Constine, L. S.; Hudson, M. M.; Kremer, L. C. M.; Skinner, R.; Vetsch, J.; Lee, J. L.; Michel, G.
abstract

Survivors of childhood, adolescent, and young adult (diagnosed when <25 years of age) cancer are at risk of mental health problems. The aim of this clinical practice guideline is to harmonise international recommendations for mental health surveillance in survivors of childhood, adolescent, and young adult cancer. This guideline was developed by a multidisciplinary panel of experts under the sponsorship of the International Guideline Harmonization Group. We evaluated concordance among existing survivorship clinical practice guidelines and conducted a systematic review following evidence-based methods. Of 7249 studies identified, 76 articles from 12 countries met the inclusion criteria. Recommendations were formulated on the basis of identified evidence in combination with clinical considerations. This international clinical practice guideline strongly recommends mental health surveillance for all survivors of childhood, adolescent, and young adult cancers at every follow-up visit and prompt referral to mental health specialists when problems are identified. Overall, the recommendations reflect the necessity of mental health surveillance as part of comprehensive survivor-focused health care.


2022 - Too Hot to Eat: Wild and Lab-Bred Lymnaea stagnalis Differ in Feeding Response Following Repeated Heat Exposure [Articolo su rivista]
Rivi, V.; Batabyal, A.; Benatti, C.; Tascedda, F.; Blom, J. M.; Lukowiak, K.
abstract

AbstractAcute extreme heat events are increasing in frequency and intensity. Understanding their effects on ectothermic organisms' homeostasis is both important and urgent. In this study we found that the exposure to an acute heat shock (30 °C for 1 hour) repeated for a seven-day period severely suppressed the feeding behavior of laboratory-inbred (W-strain) Lymnaea stagnalis, whereas the first-generation offspring of freshly collected wild (F1 D-strain) snails raised and maintained under similar laboratory conditions did not show any alterations. The W-strain snails might have inadvertently been selected against heat tolerance since they were first brought into the laboratory many (∼70) years ago. We also posit that the F1 D-strain snails do not perceive the heat shock as a sufficient stressor to alter their feeding response because their parental populations in wild environments have repeatedly experienced temperature fluctuations, thus becoming more tolerant and resilient to heat. The different responses exhibited by two strains of the same species highlight the importance of selecting the most appropriate strain for addressing questions about the impacts of global warming on organisms' physiology and behavior.


2021 - Digital Phenotyping and Dynamic Monitoring of Adolescents Treated for Cancer to Guide Intervention: Embracing a New Era [Articolo su rivista]
Blom, J. M. C.; Colliva, C.; Benatti, C.; Tascedda, F.; Pani, L.
abstract


2021 - How to humanise the COVID-19 intensive care units [Articolo su rivista]
Rivi, V.; Melegari, G.; Blom, J. M. C.
abstract


2021 - Long term memory of configural learning is enhanced via CREB upregulation by the flavonoid Quercetin in Lymnaea stagnalis [Articolo su rivista]
Batabyal, Anuradha; Rivi, Veronica; Benatti, Cristina; Blom, Johanna M. C.; Lukowiak, Ken
abstract


2021 - To eat or not to eat: a Garcia effect in pond snails (Lymnaea stagnalis) [Articolo su rivista]
Rivi, Veronica; Batabyal, Anuradha; Juego, Karla; Kakadiya, Mili; Benatti, Cristina; Blom, Johanna M C; Lukowiak, Ken
abstract

Taste aversion learning is universal. In animals, a single presentation of a novel food substance followed hours later by visceral illness causes animals to avoid that taste. This is known as bait-shyness or the Garcia effect. Humans demonstrate this by avoiding a certain food following the development of nausea after ingesting that food ('Sauce Bearnaise effect'). Here, we show that the pond snail Lymnaea stagnalis is capable of the Garcia effect. A single 'pairing' of a novel taste, a carrot slurry followed hours later by a heat shock stressor (HS) is sufficient to suppress feeding response elicited by carrot for at least 24 h. Other food tastes are not suppressed. If snails had previously been exposed to carrot as their food source, the Garcia-like effect does not occur when carrot is 'paired' with the HS. The HS up-regulates two heat shock proteins (HSPs), HSP70 and HSP40. Blocking the up-regulation of the HSPs by a flavonoid, quercetin, before the heat shock, prevented the Garcia effect in the snails. Finally, we found that snails exhibit Garcia effect following a period of food deprivation but the long-term memory (LTM) phenotype can be observed only if the animals are tested in a food satiated state.


2021 - Vortioxetine Prevents Lipopolysaccharide-Induced Memory Impairment Without Inhibiting the Initial Inflammatory Cascade [Articolo su rivista]
Alboni, S.; Benatti, C.; Colliva, C.; Radighieri, G.; Blom, J. M. C.; Brunello, N.; Tascedda, F.
abstract

Vortioxetine is a novel multimodal antidepressant that modulates a wide range of neurotransmitters throughout the brain. Preclinical and clinical studies have shown that vortioxetine exerts positive effects on different cognitive domains and neuroprotective effects. Considering the key role of microglial cells in brain plasticity and cognition, we aimed at investigating the effects of pretreatment with vortioxetine in modulating behavioral and molecular effects induced by an immune challenge: peripheral injection of lipopolysaccharide (LPS). To this purpose, C57BL/6J male mice were first exposed to a 28-day standard diet or vortioxetine-enriched diet, which was followed by an acute immune challenge with LPS. Sickness symptoms and depressive-like behaviors (anhedonia and memory impairment) were tested 6 and 24 h after exposure to LPS, respectively. Moreover, the expressions of markers of immune activation and M1/M2 markers of microglia polarization were measured in the dorsal and ventral parts of the hippocampus. The pretreatment with vortioxetine did not affect both LPS-induced sickness behavior and anhedonia but prevented the deficit in the recognition memory induced by the immune challenge. At the transcriptional level, chronic exposure to vortioxetine did not prevent LPS-induced upregulation of proinflammatory cytokines 6 h after the immune challenge but rather seemed to potentiate the immune response to the challenge also by affecting the levels of expression of markers of microglia M1 phenotype, like cluster of differentiation (CD)14 and CD86, in an area-dependent manner. However, at the same time point, LPS injection significantly increased the expression of the M2 polarization inducer, interleukin 4, only in the hippocampus of animals chronically exposed to vortioxetine. These results demonstrate that a chronic administration of vortioxetine specifically prevents LPS-induced memory impairment, without affecting acute sickness behavior and anhedonia, and suggest that hippocampal microglia may represent a cellular target of this novel antidepressant medication. Moreover, we provide a useful model to further explore the molecular mechanisms specifically underlying cognitive impairments following an immune challenge.


2021 - What can we teach Lymnaea and what can Lymnaea teach us? [Articolo su rivista]
Rivi, Veronica; Benatti, Cristina; Lukowiak, Ken; Colliva, Chiara; Alboni, Silvia; Tascedda, Fabio; Blom, Johanna M. C.
abstract


2020 - Biological and neuropsychological markers of cognitive dysfunction in unipolar vs bipolar Depression: What evidence do we have? [Articolo su rivista]
Platania, G. A.; Varrasi, S.; Castellano, S.; Godos, J.; Pirrone, C.; Petralia, M. C.; Cantarella, R. A.; Tascedda, F.; Guerrera, C. S.; Buono, S.; Caraci, F.; Blom, J. M. C.
abstract

Cognition is a critical aspect of psychopathology. The aim of this review is to evaluate and discuss evidence on the biological and neuropsychological markers of cognitive dysfunction in unipolar and bipolar Depression to improve the differential diagnosis and develop plans of personalized pharmacological treatment. The different use of biological and neuropsychological markers is reviewed and their use to support the clinical process and differential diagnosis is critically examined. While biological markers can help to reduce the risk of misdiagnosis, neuropsychological markers can be assessed more readily and with a less invasive methodology. To this end, additional research on the thresholds differentiating the cognitive dysfunction in unipolar and bipolar Depression should be conducted on specific psychometric tools proposed in this review. Most importantly future effort should be directed towards the validation of both types of markers specifically for these two populations. Finally this review contributes to the field by focusing on the clinical need of a precise differential diagnosis that, when put in a translational framework, should combine an integration of research and clinical practice allowing for a better understanding of mental health and for evidence-based clinical practice.


2020 - Lymnaea stagnalis as model for translational neuroscience research: from pond to bench [Articolo su rivista]
Rivi, Veronica; Benatti, C; Colliva, C; Radighieri, G; Brunello, N; Tascedda, F; Blom, Johanna
abstract

The purpose of this review is to illustrate how a reductionistic, but sophisticated, approach based on the use of a simple model system such as the pond snail Lymnaea stagnalis (L. stagnalis), might be useful to address fundamental questions in learning and memory. L. stagnalis, as a model, provides an interesting platform to investigate the dialog between the synapse and the nucleus and vice versa during memory and learning. More importantly, the "molecular actors" of the memory dialogue are well-conserved both across phylogenetic groups and learning paradigms, involving single- or multi-trials, aversion or reward, operant or classical conditioning. At the same time, this model could help to study how, where and when the memory dialog is impaired in stressful conditions and during aging and neurodegeneration in humans and thus offers new insights and targets in order to develop innovative therapies and technology for the treatment of a range of neurological and neurodegenerative disorders.


2020 - Psychosocial assessment of families caring for a child with acute lymphoblastic leukemia, epilepsy or asthma: Psychosocial risk as network of interacting symptoms [Articolo su rivista]
Colliva, Chiara; Cellini, Monica; dalla porta, maria francesca; Ferrari, Silvia Martina; Bergamini, Barbara Maria; Guerra, Azzurra; Di Giuseppe, Silvia; Pinto, Annamaria; Capasso, Roberto; Caprino, Daniela; Ferrari, Marta; Benatti, Cristina; Tascedda, Fabio; Blom, Johanna M. C.
abstract

The purpose of this study is to assess psychosocial risk across several pediatric medical conditions and test the hypothesis that different severe or chronic pediatric illnesses are characterized by disease specific enhanced psychosocial risk and that risk is driven by disease specific connectivity and interdependencies among various domains of psychosocial function using the Psychosocial Assessment Tool (PAT). In a multicenter prospective cohort study of 195 patients, aged 5-12, 90 diagnosed with acute lymphoblastic leukemia (ALL), 42 with epilepsy and 63 with asthma, parents completed the PAT2.0 or the PAT2.0 generic version. Multivariate analysis was performed with disease as factor and age as covariate. Graph theory and network analysis was employed to study the connectivity and interdependencies among subscales of the PAT while data-driven cluster analysis was used to test whether common patterns of risk exist among the various diseases. Using a network modelling approach analysis, we observed unique patterns of interconnected domains of psychosocial factors. Each pathology was characterized by different interdependencies among the most central and most connected domains. Furthermore, data-driven cluster analysis resulted in two clusters: Patients with ALL (89%) mostly belonged to cluster 1, while patients with epilepsy and asthma belonged primarily to cluster 2 (83% and 82% respectively). In sum, implementing a network approach improves our comprehension concerning the character of the problems central to the development of psychosocial difficulties. Therapy directed at problems related to the most central domain(s) constitutes the more rational one because such an approach will inevitably carry over to other domains that depend on the more central function.


2020 - P.304 Executive functioning and genetic variation in pediatric patients with cancer [Abstract in Rivista]
Colliva, C.; Dalla Porta, M. F.; Ferrari, M.; Benatti, C.; Cellini, M.; Brunello, N.; Blom, J. M.
abstract


2020 - Redefining operant conditioning of escape behaviour in lymnaea stagnalis [Articolo su rivista]
Benatti, C.; Rivi, V.; Colliva, C.; Radighieri, G.; Tascedda, F.; Blom, J. M. C.
abstract

The escape behaviour is one of the many behavioural responses that can be operantly conditioned in a stimulus-dependent manner in both vertebrates and invertebrates. By exposing the pond snail Lymnaea stagnalis repeatedly to a negative reinforcement its natural tendency to explore its surroundings can be operantly conditioned in both adult and aged snails. When adult snails were trained with 100 mM of KCl their number of escapes was significantly decreased and the latency to first escape was significantly increased. Our behavioural protocol allowed us to investigate memory acquisition, consolidation, and retrieval in pre-and post-training sessions over different days. From the 3rd day of training the learned response was strengthened: the number of the escapes in the post-test session remained significantly reduced even when animals were presented with distilled water. Moreover, adult snails exposed to the negative reinforcement for at least 4 days started to escape significantly less than the control group also in the pre-test session. This effect became more pronounced in the following days and was accompanied by a significant increase in the latency to first escape at the beginning of the pre-test on day 6 and 7. Aged snails, instead, showed selective deficiencies when operantly conditioned: memory retention appeared only after 7 days, while memory retrieval could not be induced. This redefined paradigm can help unravelling a variety of sophisticated cognitive phenomena in L. stagnalis and could be employed also to study the basis of memory impairment occurring during neuro-aging.


2019 - Executive functioning in children with epilepsy: Genes matter [Articolo su rivista]
Colliva, Chiara; Ferrari, Marta; Benatti, Cristina; Guerra, Azzurra; Tascedda, Fabio; Blom, Johanna Maria Catharina
abstract

Pediatric epilepsy has emerged as a chronic medical disease with a characteristic behavioral and cognitive phenotype, which includes compromised executive functioning (EF) and attention-related deficits. However, considerable interindividual variability exists; children often display very different or even opposite outcomes, and some children are more likely than others to develop neurocognitive problems in the face of similar individual and disease-related problems. The factors responsible for this interindividual variability are still largely unknown, but we do know that some genetic factors render the developing brain more susceptible to damage or traumatic experiences than others. Dopamine availability has a neuromodulatory function in the prefrontal cortex (PFC) and especially affects EF. Dopamine availability relates to polymorphisms in the gene encoding catechol-O-methyltransferase (COMT Val158Met), which in turn is affected by the methylation state of its promoter. Allelic variation of the methylenetetrahydrofolate reductase (MTHFR C677T) gene, alters methylation and may influence the methylation state of the COMT promoter. Given this, we tested the hypothesis that these polymorphisms interact in children with epilepsy, and that variability in allelic expression is associated with variability in cognitive phenotype. Executive function was tested directly and indirectly (parent-rated) in 42 children between 5 and 12 years of age. The MTHFR T allele carriers performed worse than MTHFR homozygous CC carriers on indirect EF, and a significant decline was observed when T allele carriers had at least one met allele of the COMT gene, especially on Working Memory. Direct EF was significantly compromised in COMT Val/Val carriers where reduced dopamine availability seems to confer a higher risk in a test that requests a high degree of executive attention and planning. This finding suggests that in children with epilepsy, genes that influence methylation and dopamine availability affect PFC-related EF. Therefore, we should consider genetic vulnerability as a polygenic risk, which might predispose for a particular phenotype and include specific genetic signatures as part of each patient's behavioral and cognitive profile from the moment that we start to take care of the child.


2019 - Modulation of neuroplasticity-related targets following stress-induced acute escape deficit [Articolo su rivista]
Benatti, C.; Radighieri, Giulia; Alboni, S.; Blom, J. M. C.; Brunello, N.; Tascedda, F.
abstract

Understanding resilience is a major challenge to improve current pharmacological therapies aimed at complementing psychological-based approaches of stress-related disorders. In particular, resilience is a multi-factorial construct where the complex network of molecular events that drive the process still needs to be resolved. Here, we exploit the acute escape deficit model, an animal model based on exposure to acute unavoidable stress followed by an escape test, to define vulnerable and resilient phenotypes in rats. Hippocampus and prefrontal cortex (PFC), two of the brain areas most involved in the stress response, were analysed for gene expression at two different time points (3 and 24 h) after the escape test. Total Brain-Derived Neurotrophic Factor (BDNF) was highly responsive in the PFC at 24-h after the escape test, while expression of BDNF transcript IV increased in the hippocampus of resistant animals 3 h post-test. Expression of memory enhancers like Neuronal PAS Domain Protein 4 (Npas4) and Activity-regulated cytoskeleton-associated protein (Arc) decreased in a time- and region-dependent fashion in both behavioural phenotypes. Also, the memory inhibitor Protein Phosphatase 1 (Ppp1ca) was increased in the hippocampus of resilient rats at 3 h post-test. Given the importance of neurotrophic factors and synaptic plasticity-related genes for the development of appropriate coping strategies, our data contribute to an additional step forward in the comprehension of the psychobiology of stress and resiliency.


2019 - P.1.04 Expression of histone variants H3.3 and H2a.z in the rat brain: Physiopathological and pharmacological implications [Abstract in Rivista]
Radighieri, G.; Benatti, C.; Zoli, M.; Blom, J. M. C.; Brunello, N.; Tascedda, F.
abstract

In the overall context of epigenetic modifications in charge of managing genome plasticity and dynamics [1, 2], the role of nucleosomal loading of histone variants is becoming increasingly captivating. Two replication-independent isoforms of histones H3 and H2A, namely H3.3 and H2A.Z, have caught attention because of their involvement in neuronal plasticity processes, cognitive functions and behavioral outcomes. In fact, their incorporation/eviction in nucleosomes and their turnover in neurons influence chromatin accessibility and therefore transcription. H3.3 enrichment at gene bodies and promoters of genes involved in synaptic plasticity was proved to be positively correlated with their expression, while learning-induced H2A.Z eviction in specific genes promotes gene transcription, intervening in memory consolidation processes. H3.3 is encoded by H3f3a and H3f3b independent genes, generating identical proteins, namely H3.3A and H3.3B. Notably, H3f3b gene, but not H3f3a, was proved responsive to neuronal activating stimuli as well as environmental triggers and stressful procedures [3]. H2A.Z hypervariants H2A.Z.1 and H2A.Z.2, encoded respectively by H2afz and H2afv genes, regulate both basal and stimulus-induced neuronal gene expression of independent gene sets [4]. Starting from this evidence, the purpose of this study was to characterize basal expression levels of all genes encoding for the histones variants above mentioned in rodent hippocampus and prefrontal cortex (PFC), two brain regions closely related to brain plasticity, cognition and behavior. Adult male rats (n=7) were sacrificed, their brains removed and dissected. Total RNA extraction was performed, followed by total RNA reverse transcription and Real Time PCR, where specific forward and reverse primer were used for each gene encoding for H3.3 (H3f3a and H3f3b), H2A.Z (H2afz and H2afv) and endogenous control GAPDH. Statistical analysis was performed by means of one-way ANOVA; p<0.05 was considered as a threshold for statistically significant difference. Molecular analyses revealed that, for both hippocampus and PFC, H3f3a mRNA was more expressed at the steady-state compared to H3f3b (p<0.001), as happens for H2afz mRNA, which displays higher levels than H2afv (p<0.001). Moreover, comparing hippocampal and PFC mRNA levels for each variant, H3f3a and H3f3b expression was increased in the hippocampus with respect to the prefrontal cortex (p<0.001), and a comparable outcome was showed for H2afv (p<0.001) but not for H2afz (p>0.05). Our results suggest that 1) differential basal expression levels of genes encoding for H3.3 and H2A.Z may underlie unique gene responsiveness following different stimuli, as previously hypothesized by others [3,4], and this may be crucial in highly-responsive, pathological- and environment-related tissues like hippocampus and PFC; 2) striking lower steady-state expression of H3f3b and H2afv genes might imply a major sensitivity to neuronal inputs compared to their correspondent counterparts; 3) higher expression levels in the hippocampus with respect to the PFC might underpin brain-region specific expression and function for histone variants and their isoforms. Together, these data clear the way for further studies meant at investigating stimulus-dependent regulation of H3.3 and H2A.Z gene isoforms expression and their putative involvement in the physiopathology of brain and its diseases [5]. References [1] Rigillo, G., Vilella, A., Benatti, C., Schaeffer, L., Brunello, N., Blom, J.M.C., Zoli, M., Tascedda, F., 2018. LPS-induced histone H3 phospho(Ser10)-acetylation(Lys14) regulates neuronal and microglial neuroinflammatory response. Brain Behav Immun. https://doi.org/10.1016/j.bbi.2018.09.019. [2] Ottaviani, E., Accorsi, A., Rigillo, G., Malagoli, D., Blom, J.M., Tascedda, F., 2013. Epigenetic modification in neurons of the mollusc Pomacea canaliculata after immune challe


2019 - The many faces of mitochondrial dysfunction in depression: From pathology to treatment [Articolo su rivista]
Caruso, G.; Benatti, C.; Blom, J. M. C.; Caraci, F.; Tascedda, F.
abstract

Introduction The last years of neurobiological research have transformed the way we consider mental illnesses. We have gone from a deterministic genetic view to a broader vision that includes the involvement of non-cerebral systems. This is especially true for major depression (MD). Historically, MD has been perceived as a multifactorial disorder correlated to various neurobiological changes like neurotransmitter deficits, endocrine disturbances, impaired plasticity, and neural adaptation (Benatti et al., 2016). Indeed, the development and progression of depressive disorders has been conceived as the disruption of body allostasis, defined as the process of achieving stability of physiological and mental processes through dynamic change (Wang et al., 2019). The main player in the “allostatic game” is the brain, an organ designed to integrate signals from the periphery that anticipate fluctuations, changes, and needs and coordinates allostatic mediators in order to develop successful coping mechanisms that ultimately lead to an adaptative strategy and resilience (de Kloet et al., 2005). The establishment and maintenance of these mechanisms requires large amounts of energy from the organism. Without energy, or in a partial lack of energy, the biological mechanisms necessary to respond appropriately to stimuli may not occur or be established incorrectly or abnormally. Human and animal studies suggest an intriguing link between our body’s ability to produce energy and the brain’s ability to correctly perform the complex cellular and molecular processes involved in allostatic processes. In eukaryotic cells, mitochondria are the powerhouse that produces and distributes energy to all other components. Functional or quantitative alterations of the ability of mitochondria to adequately supply energy can have important repercussions primarily on cellular processes and cascades of serial events (Herst et al., 2017) as well as on the correct functioning of the organism including mechanisms of brain plasticity, mood, and behavior in general (Allen et al., 2018). In this framework, it is particularly intriguing to think of the mitochondria as an active regulator of many of the biological phenomena involved in depression and in the efficacy of or resistance to the most widely used pharmacological treatments. Once the energetic equilibrium is compromised, the body becomes more “vulnerable.” This is especially true for stress-related disorders, such as depression. In fact, depression is often associated with energetic imbalance leading to profound effects on the disease (Zuccoli et al., 2017). The driving questions then are as follows: What happens to the brain in the presence of an energetic imbalance? Does depression or depression-related symptoms impact mitochondrial energetic efficiency? Is antidepressant efficacy mediated by mitochondrial functionality?


2018 - LPS-induced histone H3 phospho(Ser10)-acetylation(Lys14) regulates neuronal and microglial neuroinflammatory response [Articolo su rivista]
Rigillo, Giovanna; Vilella, Antonietta; Benatti, Cristina; Schaeffer, Laurent; Brunello, Nicoletta; Blom, Johanna M. C.; Zoli, Michele; Tascedda, Fabio
abstract

Epigenetic modifications of DNA and histone proteins are emerging as fundamental mechanisms by which neural cells adapt their transcriptional response to environmental cues, such as, immune stimuli or stress. In particular, histone H3 phospho(Ser10)-acetylation(Lys14) (H3S10phK14ac) has been linked to activation of specific gene expression. The purpose of this study was to investigate the role of H3S10phK14ac in a neuroinflammatory condition. Adult male rats received a intraperitoneal injection of lipopolysaccharide (LPS) (830 μg/Kg/i.p., n = 6) or vehicle (saline 1 mL/kg/i.p., n = 6) and were sacrificed 2 or 6 h later. We showed marked region- and time-specific increases in H3S10phK14ac in the hypothalamus and hippocampus, two principal target regions of LPS. These changes were accompanied by a marked transcriptional activation of interleukin (IL) 1β, IL-6, Tumour Necrosis Factor (TNF) α, the inducible nitric oxide synthase (iNOS) and the immediate early gene c-Fos. By means of chromatin immunoprecipitation, we demonstrated an increased region- and time-specific association of H3S10phK14ac with the promoters of IL-6, c-Fos and iNOS genes, suggesting that part of the LPS-induced transcriptional activation of these genes is regulated by H3S10phK14ac. Finally, by means of multiple immunofluorescence approach, we showed that increased H3S10phK14ac is cell type-specific, being neurons and reactive microglia, the principal histological types involved in this response. Present data point to H3S10phK14ac as a principal epigenetic regulator of neural cell response to systemic LPS and underline the importance of distinct time-, region- and cell-specific epigenetic mechanisms that regulate gene transcription to understand the mechanistic complexity of neuroinflammatory response to immune challenges.


2018 - Molecular changes associated with escitalopram response in a stress-based model of depression [Articolo su rivista]
Benatti, Cristina; Alboni, Silvia; Blom, Johanna Maria Catharina; Mendlewicz, Julien; Tascedda, Fabio; Brunello, Nicoletta
abstract

Converging evidence points at hypothalamus-pituitary-adrenal (HPA) axis hyperactivity and neuroinflammation as important factors involved in the etiopathogenesis of major depressive disorder (MDD) and in therapeutic efficacy of antidepressants. In this study, we examined the molecular effects associated with a response to a week-long treatment with escitalopram in the chronic escape deficit (CED) model, a validated model of depression based on the induction of an escape deficit after exposure of rats to an unavoidable stress. We confirmed our previous result that a treatment with escitalopram (10 mg/kg) was effective after 7 days in reverting the stress-induced escape deficit in approximately 50% of the animals, separating responders from non-responders. Expression of markers of HPA axis functionality as well as several inflammatory mediators were evaluated in the hypothalamus, a key structure integrating signals from the neuro, immune, endocrine systems. In the hypothalamus of responder animals we observed a decrease in the expression of CRH and its receptors and an increase in GR protein in total and nuclear extracts; this effect was accompanied by a significant decrease in circulating corticosterone in the same cohort. Hypothalamic IL-1β and TNFα expression were increased in stressed animals, while CXCL2, IL-6, and ADAM17 mRNA levels were decreased in escitalopram treated rats regardless of the treatment response. These data suggest that efficacy of a one week treatment with escitalopram may be partially mediated by a decrease HPA axis activity, while in the hypothalamus the drug-induced effects on the expression of immune modulators did not correlate with the behavioural outcome.


2017 - Immune-Neuroendocrine Interactions: Evolution, Ecology, and Susceptibility to Illness [Articolo su rivista]
Blom, Johanna M. C.; Ottaviani, Enzo
abstract

The integration between immune and neuroendocrine systems is crucial for maintaining homeostasis from invertebrates to humans. In the first, the phagocytic cell, i.e., the immunocyte, is the main actor, while in the latter, the principle player is the lymphocyte. Immunocytes are characterized by the presence of pro-opiomelanocortin (POMC) peptides, CRH, and other molecules that display a significant similarity to their mammalian counterparts regarding their functions, as both are mainly involved in fundamental functions such as immune (chemotaxis, phagocytosis, cytotoxicity, etc.) and neuroendocrine (stress) responses. Furthermore, the immune-neuroendocrine system provides vital answers to ecological and immunological demands in terms of economy and efficiency. Finally, susceptibility to disease emerges as the result of a continuous dynamic interaction between the world within and the world outside. New fields such as ecological immunology study the susceptibility to pathogens in an evolutionary perspective while the field of neuro-endocrine-immunology studies the susceptibility from a more immediate perspective.


2017 - Transcriptional effect of serotonin in the ganglia of Lymnaea stagnalis [Articolo su rivista]
Benatti, Cristina; Colliva, Chiara; Blom, Johanna Maria Catharina; Ottaviani, Enzo; Tascedda, Fabio
abstract

The serotonin system (5HT) is highly conserved in both vertebrates and invertebrates, and numerous evidence supports a biological link between 5HT and numerous animal function. In the present paper we evaluated the transcriptional effects of a serotonergic stimulation on selected targets involved in 5HT signalling and neurotransmission in the central nervous system of the great pond snail Lymnaea stagnalis. Adult snails were treated acutely (6 h) or chronically (48 h) with either 5-hydroxytrypthophan (5-HTP 1mM), the immediate precursor of serotonin, fluoxetine (FLX 1μM), a selective serotonin reuptake inhibitor, or a combination of two. The central ring ganglia were dissected and used for q-PCR gene expression analysis. Transcription was strongly induced following a chronic, but not an acute, exposure to 5-HTP in the ganglia of Lymnaea. In particular, LymCREB1 and LymP2X mRNA levels were decreased following a 6 h exposure and increased in snails receiving 5-hydroxytryptophan for 48 h. Interestingly, this effect was reduced when snails were exposed chronically to both 5-HTP and FLX, suggesting a role for SERT in mediating the effect of 5-hydroxytryptophan. These data suggest that L. stagnalis is suited to unravel the complexity of the serotonin signaling pathway.


2016 - Disease-induced neuroinflammation and depression [Articolo su rivista]
Benatti, Cristina; Blom, Johanna Maria Catharina; Rigillo, Giovanna; Alboni, Silvia; Zizzi, Francesca; Torta, Riccardo; Brunello, Nicoletta; Tascedda, Fabio
abstract

Progression of major depression, a multifactorial disorder with a neuroinflammatory signature, seems to be associated with the disruption of body allostasis. High rates of comorbidity between depression and specific medical disorders, such as, stroke, chronic pain conditions, diabetes mellitus, and human immunodeficiency virus (HIV) infection, have been extensively reported. In this review, we discuss how these medical disorders may predispose an individual to develop depression by examining the impact of these disorders on some hallmarks of neuroinflammation known to be impaired in depressed patients: altered permeability of the blood brain barrier, immune cells infiltration, activated microglia, increased cytokines production, and the role of inflammasomes. In all four pathologies, blood brain barrier integrity was altered, allowing the infiltration of peripheral factors, known to activate resident microglia. Evidence indicated morphological changes in the glial population, increased levels of circulating pro-inflammatory cytokines or increased production of these mediators within the brain, all fundamental in neuroinflammation, for the four medical disorders considered. Moreover, activity of the kynurenine pathway appeared to be enhanced. With respect to the inflammasome NLRP3, a new target whose role in neuroinflammation is emerging as being important, accumulating data suggest its involvement in the pathogenesis of brain injury following stroke, chronic pain conditions, diabetes mellitus or in HIV associated immune impairment. Finally, data gathered over the last 10 years, indicate and confirm that depression, stroke, chronic pain, diabetes, and HIV infection share a combination of underlying molecular, cellular and network mechanisms leading to a general increase in the neuroinflammatory burden for the individual.


2016 - Use of Psychotropic Drugs for Acute Psychiatric and Behavioral Problems in Paediatric Oncology: A Multi-Center Study [Abstract in Atti di Convegno]
Blom, Johanna Maria Catharina; Bertolotti, M; Barisone, E; Di Giuseppe, S; Scarponi, D; Vignola, V; Migliozzi, C; Pancaldi, Alessia; Cellini, M; Tascedda, Fabio
abstract

Background/Objectives: : Children and adolescents diagnosed with cancer are forced in the most unexpected way to cope with an extraordinary, highly unlikely event. Such an experience can be extremely disruptive. When symptoms become pathological and impair a child's development and functioning, early intervention is warranted. Given that severe childhood and adolescent adversities may negatively impact adult mental health, our aim was to critically examine, the advantages and disadvantages of acute symptom management and (short-term) psychopharmacological interventions in these severely ill patients. Design/Methods: Twenty-one patients (1-18 years old) diagnosed with cancer were enrolled in five centers. Categorical variables were analyzed with descriptive statistics and open-ended questions were examined qualitatively. Because of the importance of developmental phase, patients were divided in three age groups: 1) aged 1-6: 2) >6-11; and 3) >11-18. Variables included age, gender, the type of cancer, treatment protocol, oncologic treatment complications, the use of corticosteroids, methotrexate and vincristine, first onset of psychiatric symptoms, treatment approach to symptoms, and the possible presence of side effects due to psychotropic drugs. Results: The development of psychiatric problems differed according to tumour type and treatment protocol. Also, age was an important factor: younger children (< 6 years) and adolescents (>12) were more vulnerable, especially when the CNS was directly or indirect involved. Finally, the necessity to use psychotropic drugs was related to treatment phase (the first six months of treatment), and to treatments involving corticosteroids. Conclusion: Psychotropic drug use in children is still extremely controversial, and seems like a catch-22, in which a true solution or desired outcome is almost impossible. However, efficient and prompt management of mainly acute behavioral or psychiatric symptoms during treatment might help improve quality of life as well as psychological, functional, and medical outcomes for a child or adolescent who is trying to handle their cancer.


2015 - Molluscs as models for translational medicine [Articolo su rivista]
Tascedda, Fabio; Malagoli, Davide; Accorsi, Alice; Rigillo, Giovanna; Blom, Johanna Maria Catharina; Ottaviani, Enzo
abstract

This paper describes the advantages of adopting a molluscan model for studying the biological basis of some central nervous system pathologies affecting humans. In particular, we will focus on the freshwater snail Lymnaea stagnalis, which is already the subject of electrophysiological studies related to learning and memory, as well as ecotoxicological studies. The genome of L. stagnalis has been sequenced and annotated but the gene characterization has not yet been performed. We consider the characterization of the gene networks that play crucial roles in development and functioning of the central nervous system in L. stagnalis, an important scientific development that comparative biologists should pursue. This important effort would add a new experimental model to the limited number of invertebrates already used in studies of translational medicine, the discipline that seeks to improve human health by taking advantage of knowledge collected at the molecular and cellular levels in non-human organisms.


2015 - RESILIENCY OF CHILDREN AND ADOLESCENTS DURING TREATMENT OF ACUTE LYMPHOBLASTIC LEUKEMIA: THE USE OF 5-HTT AND BDNF POLYMORPHISMS AS BIOMARKERS [Abstract in Rivista]
Blom, Johanna Maria Catharina; Pomicino, L; Migliozzi, C; Montanari, L; Rigillo, Giovanna; Zanazzo, G; Cellini, M; Benatti, Cristina; Tascedda, Fabio
abstract

Background/Objectives: Why are some children more likely than others to develop resilience in the face of similar levels of trauma exposure as compared to others who do not. It is increasingly clear that there are critical roles for predisposing genetic and environmental influences in differentially mediating psychological risk. Resilience differs from traditional concepts of risk and protection in its focus on individual variations in response to comparable experiences. Here, we tested the hypothesis that anxiety and depression as well as neural repair and plasticity related polymorphisms may partly account for the difference in resilience observed during treatment for acute lymphoblastic leukemia (ALL). Design/Methods: Forty-five patients (1-18 yrs old) diagnosed with ALL were enrolled in two centers (protocol AIEOP-BFM-2009) and genotyped for 5HTT and BDNF (val66met). Patients and their family were subjected to a short screening battery, psychosocial testing (PAT2.1) and a specific assessment of their resiliency during treatment. The resiliency scale was composed of three subscales: Sense of Mastery (MAS), Sense of Relatedness (REL), and Emotional Reactivity (REA). Results: Patients with the SL allele of 5HTTLPR had a more compromised score in some areas of resiliency than patients with the LL allele; the presence of the S allele most affected emotional reactivity REA and sense of mastery MAS. Furthermore, age was an important factor, as younger children displayed a reduced trust and tolerance versus their surroundings. This then contributed importantly to an overall reduction in their overall resiliency. Also, resiliency was reduced one year into therapy while vulnerability was significantly enhanced. Conclusion: Genes regulating susceptibility to stress, such as 5HTTLPR and BDNF, may help to predict susceptibility towards the development of resiliency in children and adolescents treated for cancer, and may play a critical role as a predisposing factor in differentially dealing efficiently with the emotional risks related to cancer and its treatment.


2014 - Behavioural and transcriptional effects of escitalopram in the chronic escape deficit model of depression [Articolo su rivista]
Benatti, Cristina; Alboni, Silvia; Blom, Johanna Maria Catharina; Gandolfi, Francesco; Mendlewicz, Julien; Brunello, Nicoletta; Tascedda, Fabio
abstract

The study of depression is facing major challenges: first, the need to develop new drugs with a faster onset of action and second, fulfilling the unmet needs of treatment resistant patients with more effective compounds. The chronic escape deficit (CED) is a valid and useful model of depression and is based on the induction of an escape deficit after exposure of rats to an unavoidable stress. This behavioural model provides a method for evaluating the capacity of a treatment to revert the escape deficit. The majority of antidepressant drugs need to be administered for at least 3-4 weeks in order to revert the escape deficit. A 7-day treatment with escitalopram reverted the stress-induced escape deficit in approximately 50% of the animals. Escitalopram treatment decreased anxiety-related behaviours in stressed animals, by increasing the time spent in the central part of the arena with respect to saline treated stressed animals, without affecting exploratory related behaviours. Gene expression profiling was carried out in the hippocampus to identify new targets associated with the effects of stress or with the different response to escitalopram. By combining a well-validated animal model with gene expression analysis we demonstrated that the CED model may represent a perfect tool for studying treatment-resistant depression.


2014 - Interleukin 18 activates MAPKs and STAT3 but not NF-κB in hippocampal HT-22 cells [Articolo su rivista]
Alboni, Silvia; Montanari, C; Benatti, Cristina; Sanchez Alavez, M; Rigillo, Giovanna; Blom, Johanna Maria Catharina; Brunello, Nicoletta; Conti, B; Pariante, Mc; Tascedda, Fabio
abstract

Interleukin (IL)-18 is a cytokine previously demonstrated to participate in neuroinflammatory processes. Since the components of the IL-18 receptor complex are expressed in neurons throughout the brain, IL-18 is also believed to directly influence neuronal function. Here we tested this hypothesis on mouse hippocampal neurons by measuring the effects of IL-18 on three pathways previously shown to be regulated by this cytokine in non-neuronal cells: the MAPK pathways, p38 and ERK1/2 MAPKs, STAT3 and NF-κB. Experiments were carried out in vitro using the immortalized hippocampal neuronal line HT-22 or in vivo following i.c.v. injection with recombinant mouse IL-18. We showed that IL-18 did not activate NF-κB in HT-22 cells whereas it induced a rapid (within 15min) activation of the MAPK pathways. Moreover, we demonstrated that IL-18 treatment enhanced P-STAT3 (Tyr705)/STAT3 ratio in the nucleus of HT-22 cells after 30-60min of exposure. A similar increase in P-STAT3 (Tyr705)/STAT3 ratio was observed in the whole hippocampus one hour after i.c.v. injection. These data demonstrate that IL-18 can act directly on neuronal cells affecting the STAT3 pathway; therefore, possibly regulating the expression of specific genes within the hippocampus. This effect may help to explain some of the IL-18-induced effects on synaptic plasticity and functionality within the hippocampal system.


2013 - Epigenetic modification in neurons of the mollusc Pomacea canaliculata after immune challenge [Articolo su rivista]
Ottaviani, Enzo; Accorsi, Alice; Rigillo, Giovanna; Malagoli, Davide; Joan M. C., Blom; Tascedda, Fabio
abstract

In human and rodents, the transcriptional response of neurons to stress is related to epigenetic modifications of both DNA and histone proteins. To assess the suitability of simple invertebrate models in studying the basic mechanisms of stress-related epigenetic modifications, we analyzed epigenetic modifications in neurons of the freshwater snail Pomacea canaliculata after the injection of Escherichia coli-derived lipopolysaccharide (LPS). The phospho-acetylation of histone H3, together with the induction of stress-related factors, c-Fos and HSP70, were evaluated in large and small neurons of the pedal ganglia of sham- and LPS-injected snails. Immunocytochemical investigations showed that after LPS injection, the immunopositivity towards phospho (Ser10)-acetyl (Lys14)-histone H3 and c-Fos increases in the nuclei of small gangliar neurons. Western blot analysis confirmed a significant increase of phospho (Ser10)-acetyl (Lys14)-histone H3 in nuclear extracts from 2h LPS-injected animals. c-Fos protein levels were significantly augmented 6h after LPS injection. Immunocytochemistry and western blot indicated that no changes occurred in HSP70 distribution and protein levels. To our knowledge this is the first demonstration of epigenetic changes in molluscan neurons after an immune challenge and indicate the gastropod P. canaliculata as a suitable model for evolutionary and translational studies on stress-related epigenetic modifications.


2013 - The injection of LPS induces epigenetic changes in Pomacea canaliculata neurons. XIII Meeting of the Italian Association of Developmental and Comparative Immunology, Palermo, Inv. Surv. J., 10: 16, 2013 [Abstract in Rivista]
Accorsi, Alice; Rigillo, Giovanna; Malagoli, Davide; Blom, Johanna Maria Catharina; Tascedda, Fabio; Ottaviani, Enzo
abstract

The injection of LPS induces epigenetic changes in Pomacea canaliculata neurons


2012 - Transcriptional profiles underlying vulnerability and resilience in rats exposed to an acute unavoidable stress [Articolo su rivista]
Benatti, Cristina; Valensisi, Cristina; Blom, Johanna Maria Catharina; Alboni, Silvia; Montanari, Claudia; Ferrari, Francesco; Tagliafico, Enrico; Julien, Mendlewicz; Brunello, Nicoletta; Tascedda, Fabio
abstract

A complex interplay between gene and environment influences the vulnerability or the resilience to stressful events. In the acute escape deficit (AED) paradigm, rats exposed to an acute unavoidable stress (AUS) develop impaired reactivity to noxious stimuli. Here we assessed the behavioral and molecular changes in rats exposed to AUS. A genome-wide microarray experiment generated a comprehensive picture of changes in gene expression in the hippocampus and the frontal cortex of animals exposed or not to AUS. Exposure to AUS resulted in two distinct groups of rats with opposite behavioral profiles: one developing an AED, called “stress vulnerable,” and one that did not develop an AED, called “stress resilient.” Genome-wide profiling revealed a low percentage of overlapping mechanisms in the two areas, suggesting that, in the presence of stress, resilience or vulnerability to AUS is sustained by specific changes in gene expression that can either buffer or promote the behavioral and molecular adverse consequences of stress. Specifically, we observed in the frontal cortex a downregulation of the transcript coding for interferon-β and leukemia inhibitory factor in resilient rats and an upregulation of neuroendocrine related genes, growth hormone and prolactin, in vulnerable rats. In the hippocampus, the muscarinic M2 receptor was downregulated in vulnerable but upregulated in resilient rats. Our findings demonstrate that opposite behavioral responses did not correspond to opposite regulatory changes of the same genes, but resilience rather than vulnerability to stress was associated with specific changes, with little overlap, in the expression of patterns of genes.


2011 - Central effects of a local inflammation in three commonly used mouse strains with a different anxious phenotype [Articolo su rivista]
Benatti, Cristina; Alboni, Silvia; Montanari, Claudia; Caggia, Federica; Tascedda, Fabio; Brunello, Nicoletta; Blom, Johanna Maria Catharina
abstract

As in humans, genetic background in rodents may influence a peculiar set of behavioural traits such as sensitivity to pain and stressors or anxiety-related behaviours. Therefore, we tested the hypothesis that mice with different genetic backgrounds [outbred (CD1), inbred (C57BL/6J) and hybrid (B6C3F1) adult male mice] display altered reactivity to pain, stress and anxiety related behaviours. We demonstrated that B6C3F1 mice displayed the more anxious phenotype with respect to C57BL/6J or CD1 animals, with the latter being the less anxious strain when tested in an open field and on an elevated plus maze. No difference was observed across strains in thermal sensitivity to a radiant heat source. Mice were then treated with a sub-plantar injection of the inflammatory agent Complete Freund's Adjuvant (CFA), 24h later they were hyperalgesic with respect to saline exposed animals, irrespective of strain. We then measured intra-strain differences and CFA-induced inter-strain effects on the expression of various genes with a recognized role in pain and anxiety: BDNF, IL-6, IL-1β, IL-18 and NMDA receptor subunits in the mouse thalamus, hippocampus and hypothalamus. The more anxious phenotype observed in B6C3F1 hybrid mice displayed lower levels of BDNF mRNA in the hippocampus and hypothalamus when compared to outbred CD1 and C57BL/6J inbred mice. CFA led to a general decrease in central gene expression of the evaluated targets especially in CD1 mice, while BDNF hypothalamic downregulation stands out as a common effect of CFA in all three strains evaluated


2011 - Constitutive and LPS-regulated expression of interleukin-18 receptor beta variants in the mouse brain [Articolo su rivista]
Alboni, Silvia; Montanari, Claudia; Benatti, Cristina; Blom, Johanna Maria Catharina; Simone, Ml; Brunello, Nicoletta; Caggia, Federica; Guidotti, G; Marcondes, Mc; Sanchez Alavez, M; Conti, B; Tascedda, Fabio
abstract

Interleukin (IL)-18 is a pro-inflammatory cytokine that is proposed to be involved in physiological as well as pathological conditions in the adult brain. IL-18 acts through a heterodimer receptor comprised of a subunit alpha (IL-18Rα) required for binding, and a subunit beta (IL-18Rβ) necessary for activation of signal transduction. We recently demonstrated that the canonical alpha binding chain, and its putative decoy isoform, are expressed in the mouse central nervous system (CNS) suggesting that IL-18 may act on the brain by directly binding its receptor. Considering that the co-expression of the beta chain seems to be required to generate a functional receptor and, a short variant of this chain has been described in rat and human brain, in this study we have extended our investigation to IL-18Rβ in mouse. Using a multi-methodological approach we found that: (1) a short splice variant of IL-18Rβ was expressed in the CNS even if at lower levels compared to the full-length IL-18Rβ variants, (2) the canonical IL-18Rβ is expressed in the CNS particularly in areas and nuclei belonging to the limbic system as previously observed for IL-18Rα and finally (3) we have also demonstrated that both IL-18Rβ isoforms are up-regulated in different brain areas three hours after a single lipopolysaccharide (LPS) injection suggesting that IL-18Rβ in the CNS might be involved in mediating the endocrine and behavioral effects of LPS. Our data highlight the considerable complexity of the IL-18 regulation activity in the mouse brain and further support an important central role for IL-18.


2011 - Stress induces altered CRE/CREB pathway activity and BDNF expression in the hippocampus of glucocorticoid receptor-impaired mice [Articolo su rivista]
Alboni, Silvia; Tascedda, Fabio; Corsini, Daniela; Benatti, Cristina; Caggia, Federica; Capone, Giacomo; Barden, N; Blom, Johanna Maria Catharina; Brunello, Nicoletta
abstract

The gene coding for the neurotrophin Brain-Derived Neurotrophic Factor (BDNF) is a stress-responsive gene. Changes in its expression may underlie some of the pathological effects of stress-related disorders like depression. Data on the stress-induced regulation of the expression of BDNF in pathological conditions are rare because often research is conducted using healthy animals. In our experiments, we used transgenic mice with glucocorticoid receptor impaired (GR-i) expression in the hypothalamus created as a tool to study the neuroendocrine changes occurring in stress-related disorders. First, under basal condition, GR-i mice displayed lower levels of BDNF exons IX and IV and decreased CRE(BDNF) binding activity with respect to wild-type (WT) mice in the hippocampus. Then, we exposed GR-i and WT mice to an acute restraint stress (ARS) to test the hypothesis that GR-i mice display: 1] different ARS induced expression of BDNF, and 2] altered activation of signaling pathways implicated in regulating BDNF gene expression in the hippocampus with respect to WT mice. Results indicate that ARS enhanced BDNF mRNA expression mainly in the CA3 hippocampal sub-region of GR-i mice in the presence of enhanced levels of pro-BDNF protein, while no effect was observed in WT mice. Moreover, ARS reduced CREB signaling and binding to the BDNF promoter in GR-i mice but enhanced signaling and binding, possibly through ERK1/2 activation, in WT mice. Thus, life-long central GR dysfunction resulted in an altered sensitivity at the transcriptional level that may underlie an impaired response to an acute psycho-physical stress.


2010 - CONDIZIONI MEDICHE CHE POSSONO DETERMINARE DISABILITA' INTELLETTIVA [Capitolo/Saggio]
Blom, Johanna Maria Catharina; Ciotti, F; Lassi, S.
abstract

Il ritardo mentale o disabilità intellettiva è secondario o associato a molte differenti patologie croniche che si manifestano principalmente durante lo sviluppo. Negli ultimi anni si è assistito a un crescente interesse nei confronti delle conseguenze neurocognitive derivanti da condizioni mediche o da terapie ad esse conseguenti, che coinvolgono, direttamente o indirettamente, il Sistema Nervoso Centrale (SNC). Gli effetti di condizioni mediche, come la Leucemia Linfoblastica Acuta (LLA), l’asma o il diabete non sono né trasparenti né diretti. Le conseguenze sul versante neurocognitivo e neurocomportamentale sono il risultato non solo della condizione medica ma anche dell’interazione di quest’ultima e delle terapie ad essa necessarie con lo sviluppo, il tempo e le capacità di resilience. Le attuali ricerche suggeriscono che i profili neurocognitivi e i fenotipi comportamentali risultanti da una determinata condizione medica debbano essere considerati come la risultate di un algoritmo che esprime il rischio biologico, associato alle condizioni mediche, moderate dallo sviluppo del bambino, dall’età e dal periodo di insorgenza della malattia e, non ultima, dalla capacità di resilience del bambino, della famiglia, della scuola e della società in generale. In presenza di un danno al SNC la domanda che ci dobbiamo porre è: alla base del declino vi è un processo di natura biologica, psicologica o entrambi? E, più specificamente: la patologia o il trattamento hanno deteriorato un processo psicologico elementare (memoria, attenzione, funzioni esecutive), che svolge un ruolo critico nello sviluppo futuro del soggetto.


2010 - Il concetto di qualità di vita nelle diverse età [Capitolo/Saggio]
Bertelli, M; Blom, Johanna Maria Catharina; Manzotti, S; Verri, A.
abstract

L’attenzione e l’interesse nel proteggere i diritti, la salute e il benessere delle persone, adolescenti e bambini e del loro sviluppo è cresciuta in modo esponenziale nell’ultimo decennio. La trasformazione sociale che hanno subito l’infanzia e l’adolescenza nella società moderna riflette, e nello stesso tempo ritrae, il passaggio da una concezione che vede i genitori con piena e illimitata giurisdizione nei confronti dei loro figli, ad una visione nella quale il benessere dei minori e di persone con disabilita intellettiva è concepito sempre più come una distinta e indipendente responsabilità sociale per la quale sono richiesti investimenti nell’ambito dell’educazione, della salute e di altre istituzioni. Contemporaneamente, si è assistito ad una sempre più crescente mole di evidenze che il loro benessere e sviluppo è influenzato sia dalla famiglia che dalle istituzioni sociali, dalle norme e dai valori culturali prodotti dalla società stessa. Questa prospettiva vede la persona e il suo sviluppo come condizionata da ciascuna delle istituzioni presenti, la scuola, i servizi sociali e il sistema sanitario, i quali giocano un ruolo estremamente importante nel preparare l’individuo ad affrontare la società moderna e a diventare adulti, preparandoli alla vita che si fa strada in un mondo sempre più complesso. Considerando le numerose evidenze che vedono il benessere e la qualità di vita come un costrutto complesso e molto particolare, emerge la necessità di avere una concezione di salute comprensiva e integrata che rifletta le dinamiche (che influenzano la persona nell’arco della vita) proprie della natura dell’età dello sviluppo. Questo concetto dovrebbe essere basato sulle migliori evidenze scientifiche e fornire le basi sia per misurare sia per migliorare la qualità di vita e la salute delle persone con DI. Il riconoscimento che la salute ed il benessere sono il risultato di un’interazione tra fattori biologici psicologici socioculturali e fisici richiede che la qualità di vita venga promossa usando il legame tra i persone con DI, la famiglia e la comunità. Di conseguenza la QdV viene vista come una risorsa di ogni giorno non come un oggetto di vita. Questa definizione vede la QdV come una risorsa positiva che dà all’individuo la possibilità di interagire con il proprio ambiente e di rispondere alle necessità e ai cambiamenti della vita in modo suo. Inoltre, questa prospettiva incorpora la concezione di sviluppo e in particolare di uno dei principi fondamentali: l’ottimizzazione e il mantenimento del funzionamento nel corso del tempo.


2010 - Perinatal psychopathology: characterisation of a selected italian women sample [Abstract in Rivista]
Petrilli, Greta; G., Rizzi; R., Anniverno; C., Mencacci; Blom, Johanna Maria Catharina
abstract

Psychopathology during pregnancy and postpartum period is a clinical-medical affair, as well as a social one. For many woman, pregnancy and postpartum may constitute a trigger, moreover if a woman is, or have been in her life, already affected by a manifest psychopathology or an asymptomatic one. Primary-preventive approach should be considered in preconception planning with all women in childbearing age who have or are at risk for psychopathology and psychiatric illness. For them, preventive and healing standardized and evidence-based programs are needed, in particular with respect of pharmacological treatment in a so critical period; even if is not proved that any specific psychotropic drug is completely safe, due to the fact that all psychotropic medication cross the placenta barrier, there are guidelines to follow. It's as well important to highlight that even if lots have to be studied, evidence suggests that untreated depression, rather than treatment with antidepressant during pregnancy, results in adverse outcomes. Resources, resilence, copying abilities assessment, risk and protective factors evaluation, together with pharmacological treatment costs-benefits balance, are the first steps for a personalized and effective healing program. from a study on a high risk and selected sample recruited from PsicheDonna Center-Milan-Italy (Macedonio-Melloni, Fatebenefratelli Hospital) will be discussed. This center is specialized in women's lifecycle mood disorders; the characterization of this peculiar sample will be presented, with respect to: - diagnosis -risk and protective factors configuration - assessment tools - pharmacological treatment planning - clinical healing activities adopted - intervention and preventive model developed.


2009 - Early neonatal inflammation affects adult pain reactivity and anxiety related traits in mice: genetic background counts [Articolo su rivista]
Benatti, Cristina; Alboni, Silvia; Capone, Giacomo; Corsini, Daniela; Caggia, Federica; Brunello, Nicoletta; Tascedda, Fabio; Blom, Johanna Maria Catharina
abstract

Protracted or recurrent pain and inflammation in the early neonatal period may cause long-lasting changes in central neural function. However, more research is necessary to better characterize the long-term behavioral sequelae of such exposure in the neonatal period. Objectives: (1) to study whether timing of postnatal exposure to persistent inflammation alters responsiveness to thermal pain in the adult animal; (2) to assess whether animals experiencing early postnatal chronic inflammation display altered anxiety related behavior; (3) to study the importance of genetic background. Newborn mice (outbred strain, CD1 and F1 hybrid strain, B6C3F1) received an injection of Complete Freund's Adjuvant (CFA) or saline on either postnatal day 1 or 14 (PND1; PND14) into the left hind paw. Pain to radiant heat and anxiety were examined in 12-week-old adult animals. Adult baseline PWL was significantly decreased in CD1 mice exposed to CFA on PND 1 and 14 as compared to their saline treated counterparts. B6C3F1 mice exposed to CFA on PND14 showed markedly reduced baseline PWL compared to the PND14 saline group. Persistent inflammation experienced by B6C3F1 mice on PND1 failed to affect baseline adult thermal responsiveness. Adult mice, CD1 and B6C3F1, displayed low anxiety traits only if they had been exposed to persistent inflammation on PND1 and not on PND14. Our research suggests a role for genetic background in modulating long-term behavioral consequences of neonatal persistent inflammation: the data support the hypothesis that pain experienced very early in life differentially affects adult behavioral and emotional responsiveness in outbred (CD1) and hybrid mice (B6C3F1).


2009 - Gene expression profile of the hippocampus of a behavioural model of depression [Abstract in Rivista]
Valensisi, Cristina; Caggia, Federica; Alboni, Silvia; Benatti, Cristina; Ferrari, F; Mendlewicz, J; Blom, Johanna Maria Catharina; Brunello, Nicoletta; Tascedda, Fabio
abstract

Although the neurobiological basis of depression has not been fully elucidated, numerous studies have emphasized that in the etiology of depression stress may be the most significant cause, together with genetic vulnerability. Stress induces a coordinated and complex response that is adaptive and integral to survival. The brain's ability to adapt and change over time is refered to neuroplasticity and long-term plasticity in the brain requires changes in gene expression. However, exposure to intense or chronic stressors leads to an increased risk for the development of stress-related disorders including major depression. Numerous studies demonstrate that neuronal atrophy and loss of plasticity occur in hippocampus in response to stress and depression. Therefore, the hippocampal region may play a central role in depressive illness. Likewise changes in gene expression underlying the plasticity of hippocampal structures appear to be relevant in undenstanding the molecular and cellular mechanisms involved in the etiology as well as the treatment of depression, and the mechanisms leading vulnerability or resilience to stress. In fact, humans display a remarkable heterogeneity in their responses to stress and adversity. Although we are beginning to understand how maladaptive neurobiological changes may contribute to depression, relatively little is known about the molecular mechanisms that may underlie stress resilience. Here we set out to investigate the changes in the gene expression profile underlying the effects of stress on the hippocampus using a behavioural paradigm of depression, the chronic escape deficit model [1], which is based on the modified reactivity of rats to external stimuli, the escape deficit, induced by exposure to intense and unavoidable stress. The chronic escape deficit model starts as an acute escape deficit which can be indefinitely sustained by repeated administration of mild stressors. This approach has proved to be a valid and useful model of depression because it consider depressive symptoms like behavioural despair. We performed gene expression profiling in the rat hippocampus, using GeneChip Rat Exon Array (Affymetrix). Using this new platform we carried out analyses of gene expression on three different levels: gene, transcript and exon level analyses. The behavioural results showed that exposure to intense and unavoidable stressful procedure induced escape deficit only in 60% of them. Whereas the animals remaining display a behaviour apparently identical to control animals which did not undergo the stressful procedure. Comparing gene expression profiles and performing functional analysis on differently expressed genes we have indicated multiple pathways that may be involved in the underlying mechanisms of stress condition associated with escape deficit. Moreover we identified possible cellular functions and biological processes that could represent targets that may contribute to mediate the effects of stress on the hippocampal plasticity. Such as, gene expression profiling of stress-vulnerable and stress-resilient animals revealed distinct transcriptional profiles, suggesting that resilient behaviour represents an active neurobiological process and not simply the absence of vulnerability.


2009 - Mapping of the full length and the truncated interleukin-18 receptor alpha in the mouse brain [Articolo su rivista]
Alboni, Silvia; Cervia, D; Ross, B; Montanari, Claudia; Gonzalez, As; Sanchez Alavez, M; Marcondes, Mc; De Vries, D; Sugama, S; Brunello, Nicoletta; Blom, Johanna Maria Catharina; Tascedda, Fabio; Conti, B.
abstract

The cytokine IL-18 acts on the CNS both in physiological and pathological conditions. Its action occurs through the heterodimeric receptor IL-18Rα β. To better understand IL-18 central effects, we investigated in the mouse brain the distribution of two IL-18Rα transcripts, a full length and an isoform lacking the intracellular domain hypothesized to be a decoy receptor. Both isoforms were expressed in neurons throughout the brain primarily with overlapping distribution but also with some unique pattern. These data suggest that IL-18 may modulate neuronal functions and that its action may be regulated through expression of a decoy receptor.


2009 - Psychopathology during pregnancy and postpartum: characterization of a selected high risk Italian sample [Abstract in Rivista]
Petrilli, Greta; Anniverno, R; Mencacci, C; Blom, Johanna Maria Catharina
abstract

Psychological distress is common during pregnancy but the field of perinatal-psychology and related research as well as health services have focused their attention essentially on the post-partunl period. New data suggest that stress and psychopathology during pregnancy may be associated with significant risks for the mother and the baby and may lead to detrimental effects for both. Maternal psychopathology is related to reduced quality of life, higher rate of risk behaviors, postpartunl psychopathology, and to a decline in the quality of dyadic relationship. Antenatal stress and psychological disease and their underlying neuroendocrine changes are associated with poor pregnancy and birth outcomes. Maternal stress and psychopathology together with fetal vulnerability and other ~ediating factors, such as pharmachological treatment, may determme long-term consequences by altering developmental processes, affecting the structural development of certain brain areas circuits, and systems, as well as brain functioning. ' ~fter h~ving studied a sample obtained from the general population, thIS study focused on a selected and high risk sample of women diagnosed with psychopathology and recruited from a center specialized in Women's lifecycle mood disorders (psicheDonna Center-Milan). General aim: The general aim of this study was threefold: - to study different manifestations ofpsychological illness as well as to detect risk and protective factors in this selected sample of pregnant and postpartunl women - to analyze the characteristics of these women in order to understand the mechanisms underlying the interaction between protective and risk factors which may predict the course of psychopathological manifestations across pregnancy and beyond. - to analyze, in follow-up, the choice and efficacy of pharmacological and-or psychotherapy treatment of these women. Methods: A sample of91 pregnant and postpartunl women was enrolled from the Center. Women were subjected to a test battery in order to evaluate: - ~ndex ofpregnancy specific-related anxiety (PRAQ-R, Huizink) - mdex of State Anxiety and of Trait Anxiety, as defined by Spielberger (STAI-Y, Spielberger) - ananmestic data and risk and protection factors (scale constructed ad hoc and PDPI, Tatano Beck) - index of depressionlpostpartunl depression (EPDS, Cox). Conclusions and Considerations: Differences were found between ~is sample and the one from the general population, not only m test scores but overall in the role played by risk and protection factors. The presence of pregnancy-related specific anxiety (detected by PRAQ-R) was found more in the general population: a working hypothesis as to the underlying cause was developed. Women recruited from the Center are characterized by a peculiar configuration of risk and protection factors, where a previous history of psychopathology seems to play a prominent role in defining the sample. This type of evidence indicates a possible new key point with respect to intervention and prevention, that is, the previous history of psychopathology. Consequently we need to consider the necessity of different approaches in the use of screening tools, and in the development of preventive measures and healing programs, and tailor all activities and interventions to the patient in order to be effective. This has lead to new evidence-based perspectives for intervention.


2008 - Impaired stress-induced regulation of brain derived neurotrophic factor expression in hippocampus of glucocorticoid receptor impaired mice: Model of depression [Abstract in Rivista]
Alboni, Silvia; Corsini, Daniela; Caggia, Federica; Benatti, Cristina; Capone, Giacomo; Barden, N; Blom, Johanna Maria Catharina; Tascedda, Fabio; Brunello, Nicoletta
abstract

Objective: The gene codifying for the neurotrophin Brain Derived Nurotrophic Factor (BDNF) is a stress-responsive gene and alteration in its expression may be important in producing some of the pathophysiological effects of stress in the hippocampus as seen in stress-related pathologies like depression. While the effects of stress procedures on the regulation of BDNF expression was widely investigated in hippocampus of healthy control animals, the stress-induced effects on BDNF hippocampal expression in “pathological” condition are still lacking. In order to deepen our knowledge in the understanding of the effects of an acute stressful procedure on molecular targets of synaptic plasticity we used transgenic mice with impaired glucocorticoid receptor (GR-i) expression that represent an animal model of depression. The hypothesis was tested that a single period of restraint stress (6 hours) affects BDNF mRNA expression in the hippocampus of GR-i mice differently than in wild-type (WT) mice. Methods: Using real time RT-PCR we evaluated the effects of a 6 hours acute stress on the levels of BDNF coding exon VIII and the activity regulated BDNF exon IV mRNA. In the WT and in the GR-i animals, the hippocampal levels of the two BDNF exons, immediately after the stress ended, were significantly lower in stressed animals with the respect to respective control unstressed animals. However, for the BDNF exon IV mRNA the reduction is most pronounced inWT animals and two-way ANOVA followed by Bonferroni posttest revealed a significant interaction between stress response and genotype at the level of BDNF exon IV mRNA expression. Results: The BDNF gene is a very complex gene regulated by a wide array of stimuli and signalling pathways. An electophoresis mobility shift assay (EMSA) was used to study DNA-binding activity of two transcription factors with an important role in controlling synaptic plasticity most likely trough an involvement BDNF: the cAMP responsive element binding (CREB) protein and the nuclear factor kB (Nf-kB). Taken together, our results show a different binding activity of these transcription factors in GR-i mice with respect to WT mice following acute stressful conditions. Conclusion: The identification of the molecular mechanisms activated by stress in GR-i mice model of depression may contribute to the development of new strategies that reducing neuron vulnerability to stress and prevent neurophatologocal alteration in the hippocampus.


2008 - Molecular effects of subchronic andchronic treatment with escitalopram inthe rat central nervous system [Abstract in Rivista]
Benatti, Cristina; Alboni, Silvia; Capone, Giacomo; Corsini, Daniela; Caggia, Federica; Blom, Johanna Maria Catharina; Tascedda, Fabio; Brunello, Nicoletta
abstract

A clear understanding of the mechanisms behind depressionand its treatment is a critical issue for amelioratethe effectiveness of existing antidepressants. Acutely,antidepressant drugs increase synaptic concentrations ofmonoamines, but clinical efficacy requires several weeksof continuous treatment, proposing a key role for timedependentneural adaptations, perhaps induced by acutesynaptic actions, in their therapeutic efficacy.Escitalopram is the S(+) enantiomer of citalopram, oneof the most widely prescribed serotonin selective reuptakeinhibitor (SSRIs) antidepressants. In the chronic mildstress model of depression sucrose intake was alreadynormalized after one week of treatment.We evaluated the effects of a subchronic or a chronictreatment with escitalopram on expression levels of someof the main targets of antidepressant drugs such as theneurotrophin Brain Derived Neurotrophic Factor (BDNF),the transcription factors cAMP Response Element Binding(CREB) [1] Protein and Calcium Responsive Factor(CaRF).Sprague-Dawley rats were treated for 7 days (subchronic)or 21 days (chronic) with either escitalopram(10 mg/kg die i.p) or saline (1 mL/kg die); BDNF, CREBand CaRF mRNAs were evaluated using RNAse ProtectionAssay in hippocampus and prefrontal cortex.No difference was observed on BDNF, CREB andCaRF expression in the hippocampus of rats treatedsubchronically with escitalopram with respect to the grouptreated with saline. In contrast a significant inductionof BDNF mRNA was observed in prefrontal cortexof escitalopram-treated animals with respect to salinetreated ones. CaRF expression patterns were similar.Escitalopram for 7 days caused a significant induction ofCaRF mRNA with respect to the group treated with saline(p<0.05; Dunnett t-test), on the other hand CREB mRNAremained unaffected. Following a chronic treatment withEscitalopram, BDNF, CREB and CaRF mRNA levels weresignificantly decreased with respect to the group treatedwith saline in hippocampus (p<0.05; Dunnett t-test),while a 21 day treatment with escitalopram failed toproduce changes in gene expression in prefrontal cortex.These results showed that escitalopram is able todifferentially affect BDNF, CREB and CaRF expressionwith respect to treatment duration and that the observedeffects are area-specific.Consequently, to further investigate the possiblemolecular mechanisms underlying the observed effectson gene expression we evaluated by western blottingsome of the main signalling pathways regulating CREB aswell as BDNF expression, such as p38 MAPK (Mitogen-Activated Protein Kinase), CaMKII (Calcium CalmodulineKinase), ERK 1/2 (Extracellular Signal-Regulated Kinase)and CREB itself [1].Our study demonstrates that:1. A subchronic treatment with escitalopram inducesBDNF and CaRF expression in prefrontal cortexprobably through activation of p38 MAPK signallingpathway.2. A 21 day escitalopram treatment reduces hippocampalBDNF, CaRF, CREB gene expression and also CREBphosphorylated nuclear levels.Spatially distinct signalling pathways may be involvedin mediating the differential effect on gene expressionobserved following either a subchronic or a chronictreatment with escitalopram.


2007 - Repetitive acute pain in infants born preterm: an age-specific nonpharmacological approach [Abstract in Rivista]
Petrilli, Greta; Rovelli, R; Barera, G; Blom, Johanna Maria Catharina
abstract

Purpose of the study: to examine the age-related effectiveness of simple non-pharmacological interventions in reducing procedural pain in ex-preterm infants during a series of repetitive immunizations. Background: Infant pain is of critical interest, especially with respect to premature infants often exposed to protracted pain and recurring painful procedures. Despite the accumulating evidence that preterm neonates are highly sensitive to pain and that neonatal procedural pain is harmful and may lead to changes in neural development, treatment for painful procedures is limited. Children born preterm routinely undergo a series of monthly immunizations in order to prevent upper respiratory infections. These painful immunizations impact on an infant that experienced a mean of 14 stressful and painful procedures a day, during the period of hospitalization, which may have lasted for months. Given this, special attention is required to the development and use of age appropriate approaches that reduce the impact of painful procedures and to improve the treatment of repetitive pain in this particular group of vulnerable neonates. Methods: A Single Case Experimental Desing was used. 37 Italian children born pre-term were assigned to four non-pharmacological interventions (1: 25% sucrose solution in combination with oral stimulation by a pacifier; 2: visual–auditory distraction; 3: play interaction and 4: blowing soap bubbles). Reflecting the maturational level of the infants, considering age corrected for gestational age, each infant received the first intervention at his first immunization (out of five) and whenever no pain relieve was obtained, the next immunization was performed with the second intervention. Assessment of video-taped behaviour and crying, time to first cry, time to stop cry and total time required for the immunization procedure were used as outcome measures and assess by six independent observers. Results and Conclusions: following the maturation of the infant, visual-auditory distraction (using the more complex capacity of visual auditory integration), play interaction and blowing soap bubbles (using the capacity to participate in interactive play) all proved to be effective in delaying distress, reducing the facial display of pain and especially in reducing the time necessary to calm and console the infant. In addition, negative hospital experiences, length of stay together with gestational age and weight at birth should be considered important factors that influence the initial reaction to the first immunization. Sucrose in the presence of a pacifier significantly reduced pain and distress up to an age of 60 weeks corrected for gestational age. Furthermore these factors may underlie the extended efficacy of oral sucrose combined with a pacifier by altering the responsiveness of the immature nervous system to adverse events. This observation extends the effects of sucrose plus pacifier much beyond the period in which they are effective in term neonates. Finally, adjusting the method of non-pharmacological intervention according to age and maturational level will not only lead to the highest efficacy of pain management but will also lead to a reduction in stress as well as in time spend for the medical staff.


2006 - Acetylsalicylic acid accelerates the antidepressant effect of fluoxetine in a rat model of depression [Abstract in Rivista]
Capone, Giacomo; Alboni, Silvia; Benatti, Cristina; Tascedda, Fabio; Blom, Johanna Maria Catharina; J., Mendlewicz; Brunello, Nicoletta
abstract

Depression currently ranks fourth among the major causesof disability worldwide and by 2020, it is estimated thatunipolar major depression will rank second as a sourceof lost disability-adjusted life years (DALYs) worldwide(Murray and Lopez, 1997). To date however no singleagent is effective in all patients treated, probably due tothe different neurobiological alterations occurring for thedisorder and to individual differences in pharmacogeneticand pharmacodynamic parameters.Different therapies have been proposed to amelioratethe clinical responses of antidepressant drugs throughaugmentation or combination strategies.Another achievement in the development of newtreatments is to reduce the latency of clinical effect ofantidepressant drugs known to be characterized by 4-6weeks lag phase.Evidence has accumulated suggesting that majordepression is associated with dysfunction of inflammatorymediators and that psychiatric symptoms may occur duringinflammatory diseases. Moreover antidepressants show ananti-inflanmlatory action possibly related to their clinicalefficacy. In fact, an improvement in psychiatric symptomshas been recently reported in patients treated with antiinflammatorydrugs for other indications.These data imply that inflammation may be involved inthe pathogenesis of depression and that anti-inflanm~atorydrugs may be used as an adjunctive therapy.Among anti-inflammatory drugs acetylsalicylic acid(ASA) has been shown to act on the brain serotonergicsystem and to have a neuroprotective effect in vitro aswell as in vivo.Aim of the present study was to evaluate the effectsof combined treatment fluoxetine (FLX) plus ASA andASA alone in a behavioural model of depression:the chronic escape deficit (Gambarana et al., 2001).The chronic escape deficit model is based on themodified reactivity of rats to external stimuli inducedby exposure to unavoidable stress and allows evaluatingthe capacity of a treatment to revert the condition ofescape deficit. In this model, FLX alone needs to beadministered for at least 3 weeks in order to revert thiscondition.Our results showed that ASA (45 mg/kg) did not possessantidepressant properties in the chronic escape deficitmodel at any time tested. A combined treatment of FLX(5 mg/kg) and ASA (45 mg/kg) completely reverted thecondition of escape deficit as early as after 7 days, theeffect being already partially present after 4 days. Theeffect was maintained after 14 and 21 days of treatment.In the same experimental condition the effect of FLX(5 mg/kg) was significant only at 21 days, as previouslydemonstrated by other groups.The exact nature of the mechanisms underlying theabove behavioural effects are still unknown, neverthelessseveral hypotheses can be formulated. Further biochemicaland genetic researches could help to clarify the targets ofaction of the combined treatment FLX plus ASA for thedevelopment of more active and faster acting molecules.


2006 - Acetylsalicylic acid accelerates the antidepressant effect of fluoxetine in the chronic escape deficit model of depression [Articolo su rivista]
Brunello, Nicoletta; Alboni, Silvia; Capone, Giacomo; Benatti, Cristina; Blom, Johanna Maria Catharina; Tascedda, Fabio; Kriwin, P; Mendlewicz, J.
abstract

Evidence has accumulated suggesting that major depression is associated with dysfunction of inflammatory mediators. Moreover, antidepressants show an antiinflammatory action possibly related to their clinical efficacy. An improvement in psychiatric symptoms has been recently reported in patients treated with antiinflammatory drugs for other indications. These data imply that inflammation may be involved in the pathogenesis of depression and that anti-inflammatory drugs may be used as an adjunctive therapy. The aim of the present study was to evaluate the behavioural effect of the co-administration of acetylsalicylic acid (ASA, 45 mg/kg or 22.5 mg/kg) and fluoxetine (FLX, 5 mg/kg) in the chronic escape deficit model of depression. The chronic escape deficit model is based on the modified reactivity of rats to external stimuli induced by exposure to unavoidable stress and allows evaluation of the capacity of a treatment to revert the condition of escape deficit. In this model, FLX alone needs to be administered for at least 3 weeks to revert this condition. Our results show that combined treatment of fluoxetine and ASA completely reverted the condition of escape deficit by as early as 7 days, the effect being already partially present after 4 days. The effect was maintained after 14 and 21 days of treatment. ASA alone was ineffective at any time tested and the effect of fluoxetine was significant only at 21 days. These results, together with clinical data from preliminary results, suggest that ASA might accelerate the onset of action of selective serotonin reuptake inhibitor antidepressants.


2006 - Behavioural and molecular effects of the combined treatment fluoxetine plus acetylsalicylic acid in a rat model of depression [Abstract in Rivista]
Alboni, Silvia; Capone, Giacomo; Benatti, Cristina; Tascedda, Fabio; Blom, Johanna Maria Catharina; Mendlewicz, J; Brunello, Nicoletta
abstract

Current treatments for depression are inadequate for many patients, and different therapies have been proposed to ameliorate the clinical responses of antidepressant drugs through augumentation or combination strategies. Another achievement in the development of new treatments is to reduce the latency of clinical effect of antidepressant drugs known to be characterized by 4−6 weeks lag phase. Evidence has accumulated suggesting that major depression is associated with dysfunction of inflammatory mediators and that psychiatric symptoms may occur during inflammatory diseases. Moreover antidepressants show an anti-inflammatory action possibly related to their clinical efficacy. In fact, an improvement in psychiatric symptoms has been recently reported in patients treated with anti-inflammatory drugs for other indications. These data imply that inflammation may be involved in the pathogenesis of depression and that anti-inflammatory drugs may be used as an adjunctive therapy. Among the anti-inflammatory drugs the Acetylsalicylic acid has been shown to act on the brain serotonergic system and to have a neuroprotective effect toward brain damage. Aim of the present study was to evaluate the effects of combined treatment fluoxetine (FLX) plus acetylsalicylic acid (ASA) in a behavioural model of depression: the chronic escape deficit. The chronic escape deficit model is based on the modified reactivity of rats to external stimuli induced by exposure to unavoidable stress and allows evaluating the capacity of a treatment to revert the condition of escape deficit. In this model, FLX alone needs to be administered for at least 3 weeks in order to revert this condition. Our results showed that ASA (45 mg/kg) did not possess antidepressant properties in the chronic escape deficit model at any time tested. A combined treatment of FLX (5 mg/kg) and ASA (45 mg/kg) completely reverted the condition of escape deficit as early as after 7 days, the effect being already partially present after 4 days. The effect was maintained after 14 and 21 days of treatment. In the same experimental condition the effect of FLX (5 mg/kg) was significant only at 21 days, as previously demonstrated by other groups. The exact nature of the mechanisms underlying the above behavioural effects are still unknown, nevertheless several hypotheses can be formulated. Moreover, because a role for the neurotrophin BDNF was proposed in the clinical response to antidepressant treatment, we have determined the effect of combined treatment FLX plus ASA on hippocampal BDNF mRNA and protein in the same behavioural model. Ours data demonstrated that the hippocampal levels of BDNF mRNA were significantly increased with respect to control groups (naive and stressed) only in the animals responding (number of escape 10 out of 30 trials) to the combined treatment. Further biochemical and genetic researches could help to clarify the targets of action of the combined treatment FLX plus ASA for the development of more active and faster molecules.


2006 - Early postnatal chronic inflammation produces long-term changes in pain behavior and N-methyl-D-aspartate receptor subtype gene expression in the central nervous system of adult mice [Articolo su rivista]
Blom, Johanna Maria Catharina; Benatti, Cristina; Alboni, Silvia; Capone, Giacomo; Ferraguti, Chiara; Brunello, Nicoletta; Tascedda, Fabio
abstract

The objective of this study was to test whether postnatal chronic inflammation resulted in altered reactivity to pain later in life when reexposed to the same inflammatory agent and whether this alteration correlated with brain-region-specific patterns of N-methyl-D-aspartate (NMDA) receptor subtype gene expression. Neonatal mouse pups received a single injection of complete Freund's adjuvant (CFA) or saline into the left hind paw on postnatal day 1 or 14. At 12 weeks of age, both neonatal CFA- and saline-treated animals received a unilateral injection of CFA in the left hind paw. Adult behavioral responsiveness of the left paw to a radiant heat source was determined in mice treated neonatally with saline or CFA before and after receiving CFA as adults. Twenty-four hours later, brains were dissected and NMDA receptor subunit gene expression was determined in four different brain areas by using an RNase protection assay. The results indicated that NMDA receptor subtype gene expression in adult mice exposed to persistent neonatal peripheral inflammation was brain region specific and that NMDA gene expression and pain reactivity differed according to the day of neonatal CFA exposure. Similarly, adult behavioral responsiveness to a noxious radiant heat source differed according to the age of neonatal exposure to CFA. The data suggest a possible molecular basis for the hypothesis that chronic persistent inflammation experienced early during development may permanently alter the future behavior and the sensitivity to pain later in life, especially in response to subsequent or recurrent inflammatory events


2006 - Effective pain reduction of non-pharmacological interventions for procedural pain during repetitive immunizations of children born pre-term [Abstract in Rivista]
Petrilli, Greta; Blom, Johanna Maria Catharina
abstract

Psychological distress is common during pregnancy but the field of perinatal-psychology and related research as well as health services have focused their attention essentially on the post-partunl period. New data suggest that stress and psychopathology during pregnancy may be associated with significant risks for the mother and the baby and may lead to detrimental effects for both. Maternal psychopathology is related to reduced quality of life, higher rate of risk behaviors, postpartunl psychopathology, and to a decline in the quality of dyadic relationship. Antenatal stress and psychological disease and their underlying neuroendocrine changes are associated with poor pregnancy and birth outcomes. Maternal stress and psychopathology together with fetal vulnerability and other ~ediating factors, such as pharmachological treatment, may determme long-term consequences by altering developmental processes, affecting the structural development of certain brain areas circuits, and systems, as well as brain functioning. ' ~fter h~ving studied a sample obtained from the general population, thIS study focused on a selected and high risk sample of women diagnosed with psychopathology and recruited from a center specialized in Women's lifecycle mood disorders (psicheDonna Center-Milan). General aim: The general aim of this study was threefold: - to study different manifestations ofpsychological illness as well as to detect risk and protective factors in this selected sample of pregnant and postpartunl women - to analyze the characteristics of these women in order to understand the mechanisms underlying the interaction between protective and risk factors which may predict the course of psychopathological manifestations across pregnancy and beyond. - to analyze, in follow-up, the choice and efficacy of pharmacological and-or psychotherapy treatment of these women. Methods: A sample of91 pregnant and postpartunl women was enrolled from the Center. Women were subjected to a test battery in order to evaluate: - ~ndex ofpregnancy specific-related anxiety (PRAQ-R, Huizink) - mdex of State Anxiety and of Trait Anxiety, as defined by Spielberger (STAI-Y, Spielberger) - ananmestic data and risk and protection factors (scale constructed ad hoc and PDPI, Tatano Beck) - index of depressionlpostpartunl depression (EPDS, Cox). Conclusions and Considerations: Differences were found between ~is sample and the one from the general population, not only m test scores but overall in the role played by risk and protection factors. The presence of pregnancy-related specific anxiety (detected by PRAQ-R) was found more in the general population: a working hypothesis as to the underlying cause was developed. Women recruited from the Center are characterized by a peculiar configuration of risk and protection factors, where a previous history of psychopathology seems to play a prominent role in defining the sample. This type of evidence indicates a possible new key point with respect to intervention and prevention, that is, the previous history of psychopathology. Consequently we need to consider the necessity of different approaches in the use of screening tools, and in the development of preventive measures and healing programs, and tailor all activities and interventions to the patient in order to be effective. This has lead to new evidence-based perspectives for intervention.


2006 - Effects of acute stress on brain-derived neurotrophic factor in the hippocampus of transgenic mouse model of depression [Abstract in Rivista]
Alboni, Silvia; Blom, Johanna Maria Catharina; Corsini, Daniela; Benatti, Cristina; Capone, Giacomo; Ferraguti, Chiara; N., Barden; Tascedda, Fabio; Brunello, Nicoletta
abstract

Brain-Derived Neurotrophic Factor (BDNF) is a member of the neurotrophin family which includes a group of molecules important for the development and the maintenance of the nervous system. Since BDNF is highly expressed in the hippocampus, the action and regulation of this neurotrophin in this area has become subject of intense study. The gene codifying for BDNF is a stress responsive gene and alterations in its expression may be important in regulating some of the physiological and pathophysiological effects of chronic and acute stress in the hippocampus. Different studies show that several types of stress reduce BDNF expression in the hippocampus of control animals [Smith et al., 1995] and these works led to a neurotrophic hypothesis of depression [Nestler et al., 2002]. Nevertheless, the effect of stress on BDNF gene expression may differ between a "normal" and a "pathological" brain. In our study, we used transgenic mice with glucocorticoid receptor impaired (GRi) expression created [Pepin et al., 1992], as a tool to study the neuroendocrine changes observed in stress-related disorders, such as major depression. This GRi mouse model is characterized by dysfunctional glucocorticoid inhibitory feedback and an excessive activation of the hypothalamic pituitar~adrenal (HPA) axis, that can be restored by antidepressant drugs' treatment. The hypothesis was tested that a single period of 30 minutes of restraint stress affects BDNF expression in the hippocampus of GRi mice differently than in wildtype (WT) mice. Using RNase protection assay and in situ hybridization we had assessed the BDNF mRNA hippocampal levels, while the levels of BDNF and its precursor, pro-BDNF were analyzed by western blotting. Our results indicated that 30 minutes of restraint enhanced BDNF mRNA expression in the CA3 hippocampal subregion of GRi mice; the same stress procedure induced also a statistically significant increase of pro- BDNF level in hippocampus of GRi mice. No effect of acute stress was observed in the WT at the level of the expression of BDNE Moreover, we evaluated the effects of restraint on signalling pathways implicated in the regulation of BDNF expression (mitogen-activated protein kinase and calcium/calmodulin-dependent kinase cascades) that converge on the phosphorylation of CREB that we found down-regulated in the hippocampus of GRi mice and up-regulated in WT mice. Our data suggest that, in the presence of psychophysiological stress (restraint stress), GRi mice display altered hippocampal regulation in BDNF gene expression. Thus, life-long central GR dysfunction may negatively affects neural functioning by limiting the capacity to cope with change or acute stress, which could be a predisposing or determining factor in depression. Understanding the mechanisms underlying the induction of BDNF mRNA and accumulation of pro-BDNF in the hippocampus of GRi mice, may help to clarify the molecular basis of action of this neurotrophin and contribute to the development of new strategies reducing the vulnerability of neurons to stress, thus preventing neuropathological alterations in the hippocampus.


2005 - Neonatal persistent inflammation alters pain response and NMDA receptor expression in adult mice [Abstract in Rivista]
Benatti, Cristina; Alboni, Silvia; Ferraguti, Chiara; Tascedda, Fabio; Blom, Johanna Maria Catharina; Brunello, Nicoletta
abstract

Infant pain is of critical interest, especially with respect to premature infants and other high-risk neonates that experience many invasive and traumatic procedures early in development. The early neonatal period is characterized by great plasticity and reorganization. Sustained activation of central nervous circuits, caused by protracted and recurrent pain, may cause long-lasting changes in central neural function thus affecting developmental outcome and behavioural responsiveness to pain or stress later in life. However little is known about the neurobiological substrates underlying this ``memory'' process. The aim of our study was twofold:to study whether timing of postnatal exposure to a persistent inflammatory insult alters the responsiveness to thermal pain in the adult animal;given the role of the NMDA receptor in pain processing as well as in learning and memory, to examine if NMDA receptor subtype gene expression in specific areas of the cns is influenced by neonatal inflammation.Methods: Newborn mice received a single injection of Complete Freund's Adjuvant (CFA) or saline on either postnatal day 1, 3 or 14 (P1, P3 and P14) into the left hind paw. At twelve weeks of age paw withdrawal latency (PWL) of each animal was tested both in basal condition and 24h after an unilateral injection of 100 μL of CFA in the left hind paw. Mice were then killed by cervical dislocation and cerebral areas were removed. Using a sensitive RNAse protection assay, NMDA receptor subunit (NR1, NR2A, NR2B, NR2C) gene expression was evaluated in different brain areas; all data were processed by one-way ANOVA (p < 0.05).Results: Baseline paw withdrawal latency was significantly decreased in animals exposed to CFA at day 1 and 14 as compared to their saline exposed counterparts. Animals exposed to CFA at postnatal day 3 showed a significant increase in paw withdrawal latency with respect to saline injected animals. Twenty-four hours later a unilateral injection of CFA into the left hind paw, a significant decrease in paw withdrawal latency was observed in all experimental groups with respect to baseline values. PWL of P1 saline treated animals after CFA exposure was significantly higher than P3 and P14 saline treated mice. Adult mice exposed to an injection with CFA on postnatal day 1 exhibited reduced expression of the NMDA receptor subtype NR1 and NR2C in the hippocampus while mRNA levels for NR2A and NR2B did not differ between CFA treated and untreated mice. Exposure to CFA on postnatal day 3 and 14 did not affect adult expression levels of NMDA receptor subunits in the hippocampus. NMDA receptor subunit expression displayed a different profile in the thalamus. Exposure to CFA at P1 and P3 did not alter NMDA receptor subunit expression while exposure to CFA at P14 resulted in enhanced expression of the NR2A and NR2B subunits.Conclusions: These findings indicate that changes in NMDA receptor subtype gene expression in adult mice exposed to persistent neonatal peripheral inflammation are brain region specific and that NMDA gene expression and pain reactivity differ according to the day of neonatal exposure to CFA.


2005 - New combination therapies from animal to human [Abstract in Rivista]
Brunello, Nicoletta; Alboni, Silvia; Benatti, Cristina; Capone, Giacomo; Tascedda, Fabio; Blom, Johanna Maria Catharina; J., Mendlewicz
abstract

Evidence has accumulated suggesting that major depression is associated with dysfunction of inflammatory mediators. Antidepressants interfere with the synthesis and release of cytokines and do not exert behavioral effects in animal models of depression when hippocampal neurogenesis is blocked, a phenomenon which is occurring in the presence of inflammation. The anti-inflammatory drug acetylsalicylic acid (ASA), besides inhibiting the cyclooxigenase pathway, interacts with central serotonergic system, by increasing serotonin levels in cortex and reducing the density of different serotonin receptor subtypes. These neurochemical effects suggest a role of ASA in the treatment of depression. Therefore we studied the effect of ASA and fluoxetine combined treatment in a behavioral model of depression. The chronic escape deficit model is based on the modified reactivity of rats to external stimuli induced by exposure to unavoidable stress and allows evaluating the capacity of a treatment to revert the condition of escape deficit. Any kind of antidepressant drug needs to be administered for at least 3 weeks in order to revert this condition. The combined treatment of fluoxetine and ASA completely reverted the condition of escape deficit as early as after 7 days, the effect being already partially present after 4 days. The effect was maintained after 14 and 21 days of treatment. ASA alone was ineffective at any time tested and the effect of fluoxetine was significant only at 21 days. Given these preclinical results, an open clinical study has been started using the combination SSRI-ASA in treatment resistant depressed patients. Preliminary results suggest a potential accelerating effect of ASA in combination to SSRI.


2004 - Chronic treatment with desipramine and fluoxetine modulate BDNF, CaMKK alpha and CaMKK beta mRNA levels in the hippocampus of transgenic mice expressing antisense RNA against the glucocorticoid receptor [Articolo su rivista]
J., Vinet; Carra, Serena; Blom, Johanna Maria Catharina; Brunello, Nicoletta; N., Barden; Tascedda, Fabio
abstract

Antidepressants up-regulate the cAMP response element binding protein (CREB) and the brain-derived neurotrophic factor (BDNF) in hippocampus and these effects contribute to the protection of hippocampal neurons from stressful stimuli such as high glucocorticoid levels. CREB can be activated by both protein kinase A and by Ca2+-calmodulin-dependent protein kinases (CaMKs), which are in turn phosphorylated by their upstream activators CaMKKalpha and CaMMKKbeta. Using in situ hybridization, we examined the effects of chronic treatment with fluoxetine (FLU) or desipramine (DMI) on BDNF, CaMKKalpha and CaMKKbeta mRNAs in the hippocampus of wild-type (Wt) and transgenic (TG) mice characterized by glucocorticoid receptor (GR) dysfunction. Basal levels of CaMKKbeta were down regulated in the CA3 region of TG mice. DMI decreased the expression of both CaMKKalpha and CaMMKKbeta in the CA3 region of Wt mice. FLU up-regulated BDNF mRNA levels in the CA3 of TG animals while both FLU and DMI increased BDNF gene expression in the dentate gyrus (DG) of TG animals. Our results demonstrate a different regulation of BDNF expression by antidepressant drugs in the hippocampus of Wt and TG animals. Moreover, for the first time, a role for CaMKKs in the mechanism of action of antidepressant agents, at least in the hippocampus, is reported. These data are discussed in view of interactions existing between CaMK pathway and GR-mediated gene transcription.


2004 - Regulation of CREB function in rat frontal cortex after combined treatment with Fluoxetine and Olanzapine [Abstract in Rivista]
Capone, Giacomo; Alboni, Silvia; Blom, Johanna Maria Catharina; Ferraguti, Chiara; Brunello, Nicoletta; Tascedda, Fabio
abstract

Statement of the Study: Generally, drugs used in the treatment of depression exert their therapeutic effect after 4/6 weeks and only in 60–65% of patients. The search for an adequate and faster treatment of major depression is one of the main challenges in neuropsychopharmacology. Recently, a clinical study of treatmentresistant depressed patients without a psychotic component, showed that after only one week of treatment, Fluoxetine (a selective serotonin reuptake inhibitor antidepressant) and Olanzapine (an atypical antipsychotic agent) produced a higher level of improvement than either monotherapy alone (Shelton et al., American Journal of Psychiatry 158(1), 131–134, 2001). Furthermore, preclinical data, using microdialysis, indicated that the combination of Olanzapine and Fluoxetine resulted in an increase in the extracellular levels of dopamine and norepinephrine in the rat prefrontal cortex, an effect that was significantly bigger than after treatment with either drug alone (Zhang et al., Neuropsychopharmacology 23(3),250– 262, 2000). However, it is not yet completely understood which intracellular signaling pathway could be involved in the fast response (seen in clinical trials) to Fluoxetine plus Olanzapine co-treatment. Methods: Since antidepressant and antipsychotic drugs affect the cyclic adenosine monophosphate (cAMP) pathway, including the expression of the cAMP response element binding protein (CREB), the levels of CREB mRNA and CREB nuclear protein, total and phosphorylated, were studied in the frontal cortex of rats using RNase protection assay and Western Blotting analysis respectively. Four experimental groups were used: rats were treated for one, five or ten days with either saline, Fluoxetine (ip 10 mg/Kg), Olanzapine (sc 1 mg/Kg) or combined Fluoxetine plus Olanzapine (10 mg/Kg and 1 mg/Kg). Summary of Results: Our results show that the level of phosphorylated CREB Ser133 was significantly increased in the frontal cortex of rats receiving the combined treatment regimen (Fluoxetine plus Olanzapine) for five days. No effect was observed in acutely and ten day treated rats. Conclusion: This specific effect on CREB phosphorylation levels after five days of combined treatment with Fluoxetine plus Olanzapine might represent one of the mechanisms underlying the faster response to this therapy recently observed in several clinical trials.


2004 - Restraint stress increases the expression of brain derived neurotrophic factor in the hippocampus of a mouse model of depression [Abstract in Rivista]
Alboni, Silvia; Benatti, Cristina; Blom, Johanna Maria Catharina; Ferraguti, Chiara; Tascedda, Fabio; Barden, N; Brunello, Nicoletta
abstract

Statement of the study: Brain-Derived Neurotrophic Factor (BDNF) is a member of the neurotrophin family which includes a group of molecules important for the development and the maintenance of the nervous system. Since BDNF is highly expressed in the hippocampus, the action and regulation of BDNF in this particular area has become subject of intense study. Single or repeated immobilization stress markedly reduces both BDNF mRNA and protein levels in rat hippocampus. Consequently, BDNF is considered a stress-responsive gene, and it has been recently suggested that alterations in the expression of this growth factor may be important in regulating some of the physiological and pathophysiological effects of stress on the hippocampus. Stress-induced changes observed in the hippocampus of experimental animals resulted in a novel hypothesis attributing a central role to neurotrophic factors in both the etiology of depression and as well as in its treatment. However, the effects of stress on neurotrophic factors in the hippocampus of depressed patients remain unknown. In fact, the expression pattern of a large array of genes affected by depression or antidepressant drugs, such as BDNF, may differ between a normal and a pathological brain. Methods: In these experiments, we used transgenic (TG) mice deficient in glucocorticoid receptor (GR) functioning. This TG mouse was created as a model to study the neuroendocrine changes occurring in stress-related disorders, such as major depression. We evaluated the hypothesis that a single period of 30 minutes of restraint stress affects BDNF mRNA expression in the hippocampus of TG mice differently than in WT mice. Summary of results: BDNF mRNA was significantly increased by the stress procedure only in the hippocampus of TG mice, the induction being specific for the CA3 subregion as revealed by in situ hybridization. Moreover, we found that stress down-regulated CREB phosphorylation in the hippocampus of TG mice whereas it upregulated the level of phosphorylated CREB Ser133 in WT mice. Conclusion: These data suggest that, in the presence of emotional stress, lifelong central glucocorticoid receptor dysfunction results in altered hippocampal sensitivity, with respect to the level of neurotrophic gene expression. The understanding of the mechanisms through which psychological stress (such as restraint stress) induces BDNF mRNA in the hippocampus of TG mice, may help to clarify the biological and molecular basis of the action of neurotrophic factors and may contribute to the development of new strategies that will ultimately reduce the vulnerability of neurons and prevent neuropathological alterations in the hippocampus.


2003 - Cloning of mouse Ca2+/calmodulin-dependent protein kinase kinase beta (CaMKKbeta) and characterization of CaMKKbeta and CaMKKalpha distribution in the adult mouse brain. [Articolo su rivista]
Vinet, Jonathan; Carra, Serena; Blom, Johanna Maria Catharina; Harvey, M; Brunello, Nicoletta; Barden, N; Tascedda, Fabio
abstract

The Ca(2+)/calmodulin-dependent protein kinase kinases alpha and beta (CaMKKs alpha and beta) are novel members of the CaM kinase family. The CaMKKbeta was cloned from mouse brain. The deduced amino acid sequence shared 96.43% homology with the rat CaMKKbeta. Both the alpha and beta isoforms were widely distributed throughout the adult mouse brain. Additionally, all peripheral tissues examined displayed CaMKK alpha and beta expression.


2003 - Psicofarmacologia clinica [Traduzione in Volume]
Blom, Johanna Maria Catharina; Daniela, Tardito; Fabio, Fumagalli; Tascedda, Fabio
abstract

Il volume raccoglie le acquisizioni più recenti sull'utilizzo clinico delle principali classi di psicofarmaci impiegati nella terapia delle patologie psichiatriche di più rilevante intersse sociale. Si divide in due sezioni principali: le classi di farmaci psichiatrici e i trattamenti psicofarmacologici. Nella Sezione I, per ogni molecola all'interno di una specifica classe, sono commentati i dati di studi preclinici e in fase clinica; inoltre, sono illustrati gli aspetti farmacodinamici e farmacocinetici, le indicazioni terapeutiche, i dosaggi, gli effetti collaterali e le interazioni con altri farmaci, psichiatrici e non psichiatrici. La Sezione II presenta lo stato dell'arte della terapia farmacologica nelle principali malattie psichiatriche. Gli autori descrivono, inoltre, la farmacoterapia in speciali popolazioni, come i bambini e gli adolescenti, i pazienti affetti da malattie sistemiche e gli anziani. Alcuni capitoli son infine dedicati alla psicofarmacoterapia in situazioni particolari, quali la gravidanza, l'allattamento e le emergenze. Particolare cura è stata posta nelladattare la descrizione delle singole molecole alla realtà italiana: sono stati inseriti alcini farmaci non in commercio negli Stati Uniti ma venduti in Italia; inoltre, laddove la legislazione del nostro Paese differisce da quella americana, si è provveduto a fornire indicazioni di sicuro riferimento per lo specialista italiano. Questo volume è una preziosa fonte di informazioni per psichatri, psicofarmacologi, neurologi, geriatri e specializzandi, nonché un valido strumento di approfondimento per gli studenti delle Facoltà di Medicina e Farmacia.


2002 - Altered regulation of CREB by chronic antidepressant administration in the brain of transgenic mice with impaired glucocorticoid receptor function. [Articolo su rivista]
Blom, Johanna Maria Catharina; Tascedda, Fabio; Carra, Serena; Ferraguti, Chiara; Barden, N; Brunello, Nicoletta
abstract

Various effects of antidepressant drugs on gene transcription have been described and altered gene expression has been proposed as being a common biological basis underlying depressive illness. One target for the common action of antidepressants is a modifying effect on the regulation of postreceptor pathways and genes related to the cAMP cascade. Recent studies have demonstrated that long-term antidepressant treatment resulted in sustained activation of the cyclic adenosine 3',5'-monophosphate system and in increased expression of the transcription factor cAMP response element binding protein (CREB). A transgenic animal model of depression with impaired glucocorticoid receptor function was used to investigate the effect of chronic antidepressant treatments on CREB expression in different brain areas. Wild-type and transgenic mice received one administration of saline, desipramine, or fluoxetine, daily for 21 days. The effects of antidepressants on CREB mRNA were analyzed using a sensitive RNase protection assay. Antidepressant treatment resulted in a neuroanatomically and animal specific expression pattern of CREB. Our findings suggest that life-long central glucocorticoid receptor dysfunction results in an altered sensitivity with respect to the effects of antidepressants on the expression of CREB.


2002 - Cognitive deficits and changes in gene expression of NMDA receptors after prenatal methylmercury exposure [Articolo su rivista]
Baraldi, Mario; Zanoli, Paola; Tascedda, Fabio; Blom, Johanna Maria Catharina; Brunello, Nicoletta
abstract

Previous studies showed learning and memory deficit in adult rats that were prenatally exposed to methylmercury chloride (MMC) in an advanced stage of pregnancy (15 days). Under these conditions, the cognitive deficits found at 60 days of age paralleled particularly changes in the N-methyl-D-aspartate (NMDA) receptor characteristics. In the present study, we report the behavioral effects of a single oral dose of MMC (8 mg/kg) administered earlier at gestational day 8. The use of different learning and memory tests (passive avoidance, object recognition, water maze) showed a general cognitive impairment in the in utero-exposed rats tested at 60 days of age compared with matched controls. Considering the importance of the glutamatergic receptor system and its endogenous ligands in learning and memory process regulation, we surmised that MMC could affect the gene expression of NMDA receptor subtypes. The use of a sensitive RNase protection assay allowed the evaluation of gene expression of two families of NMDA receptors (NR-1 and NR-2 subtypes). The result obtained in 60-day-old rats prenatally exposed to MMC, showed increased mRNA levels of the NR-2B subunit in the hippocampus but not in the frontal cortex. The data suggest that the behavioral abnormalities of MMC-exposed rats might be ascribed to a neurotoxic effect of the metal that alters the gene expression of a specific NMDA receptor subunit in the hippocampus.


2001 - Modulation of glutamate receptors in response to the novel antipsychotic olanzapine in rats. [Articolo su rivista]
Tascedda, Fabio; Blom, Johanna Maria Catharina; Brunello, Nicoletta; Zolin, K; Gennarelli, Massimo; Colzi, A; Bravi, D; Carra, Serena; Racagni, G; Riva, M. A.
abstract

BACKGROUND:A disturbance in glutamate neurotransmission has been hypothesized in schizophrenia. Hence, the beneficial effects of pharmacological treatment may be related to adaptive changes taking place in this neurotransmitter system.METHODS:In this study, we investigated the modulation of ionotropic and metabotropic glutamate receptors in the rat brain following acute or chronic exposure to the novel antipsychotic olanzapine.RESULTS:In accordance with the clear distinction between classical and atypical drugs, olanzapine did not alter glutamate receptor expression in striatum. Chronic, not acute, exposure to olanzapine was capable of up-regulating hippocampal mRNA levels for GluR-B and GluR-C, two alpha-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid (AMPA)-forming subunits. This effect could be relevant for the improvement of schizophrenic alterations, which are thought to depend on dysfunction of the glutamatergic transmission within the hippocampal formation. We also found that the expression of group II glutamate metabotropic receptors was up-regulated in the frontal cortex after chronic exposure to clozapine, and to a lesser extent olanzapine, but not with haloperidol.CONCLUSIONS:The adaptive mechanisms taking place in glutamatergic transmission might prove useful in ameliorating some of the dysfunction observed in the brain of schizophrenic patients.


1999 - Regulation of ionotropic glutamate receptors in the rat brain in response to the atypical antipsychotic seroquel (quetiapine fumarate). . [Articolo su rivista]
Tascedda, Fabio; E., Lovati; Blom, Johanna Maria Catharina; P., Muzzioli; Brunello, Nicoletta; G., Racagni; M. A., Riva
abstract

The interplay between dopamine and glutamate appears to be relevant in the etiopathology of schizophrenia. Although currently used antipsychotics do not interact with glutamatergic receptors, previous results have demonstrated that the expression profile of ionotropic glutamate receptors can be regulated by drugs such as haloperidol or clozapine. In the present investigation, the mRNA levels for NMDA and AMPA receptor subunits were measured after chronic treatment with the novel antipsychotic agent Seroquel (quetiapine fumarate, quetiapine) as compared to haloperidol and clozapine. Similarly to the prototype atypical clozapine, quetiapine reduced the mRNA expression for NR-1 and NR-2C, two NMDA forming subunits, in the nucleus accumbens. Furthermore, quetiapine, but not haloperidol or clozapine, increased the hippocampal expression for the AMPA subunits GluR-B and GluR-C. The differences between classical and atypical antipsychotics, as well as among the novel agents, might be relevant for specific aspects of their therapeutic activity and could provide valuable information for the role of glutamate in specific symptoms of schizophrenia.


1996 - BetaCasomorphin causes hypoalgesia in 10-day-old-rats:evidence for central mediation [Articolo su rivista]
Blass, Em; Blom, Johanna Maria Catharina
abstract

Two experiments determined behavioral effectiveness of β-casomorphins(β-CM) in 10-d-old rats by evaluating changes in heat escape latency from a 48°C stimulus applied to a forepaw. In one study rats were injected systemically with β-CM4, -5, or -7 at a dose range of 0.1-2.5 mg/kg. Onlyβ-CM5 was effective, and the dose-response relationship was graded. The second study evaluated the locus of action of β-CM5 through two experimental manipulations: first, by injecting it (0.25 μg) into the lateral ventricles and by attempting to block its effects with systemic injections of naloxone. Second, rats received intracerebroventricular injections of naloxone (0.25 μg) and systemic injections of β-CM.β-CM was effective centrally, suggesting central detection of the drug. Naloxone injected into the lateral ventricles blocked the effects of systemic administration of β-CM, implying that circulating β-CM or their precursors cause behavioral change through central mechanisms.


1995 - Adrenalectomy reduces FGF-1 and FGF-2 gene expression in specific rat brain regions but differently affects their induction by seizeres. [Articolo su rivista]
Riva, Am; Fumagalli, F; Blom, Johanna Maria Catharina; Donati, E; Racagni, G.
abstract

We have previously reported that limbic seizures regulate the gene expression of fibroblast growth factor-2 (basic, FGF-2) according to a specific spatio-temporal pattern. In the present paper we have investigated the role of adrenal hormones on seizure-induced elevation of fibroblast growth factor-1 (acidic, FGF-1) and FGF-2 gene expression. Adrenalectomy reduces FGF-2 mRNA expression in specific brain regions, such as frontal cortex, hippocampus and striatum, whereas FGF-1 mRNA levels were decreased only in the frontal cortex. The injection of kainic acid in adrenalectomized rats produced a widespread increase of FGF-2 mRNA with a pattern similar to sham animals as indicated by in situ hybridization. In contrast, although kainate-induced elevation of FGF-1 mRNA in the hippocampus was not influenced by adrenalectomy, its induction in frontal cortex was prevented by this surgery procedure. Taken together, these data indicate that adrenal hormones play a role in the regulation of the gene expression for fibroblast growth factors, but different mechanisms are operative in their induction following seizure activity


1995 - Influence of photoperiod, green food, and water availability on reproduction in male california mice (Peromyscus californicus) [Articolo su rivista]
Nelson, Rj; Gubernick, Dj; Blom, Johanna Maria Catharina
abstract

California mice (Peromyscus californicus) breed primarily during the winter rainy season and generally terminate breeding during the dry summer months. This pattern of reproduction could be regulated by day length, availability of green vegetation, or water availability. The effects of photoperiod and green vegetation on reproduction were examined in Experiment 1 by housing adult male P. californicus either in long (LD 14:10) or short (LD 8:16) photoperiods for 10 weeks with ad lib food and water availability. A subset of animals in each photoperiod treatment group also received supplements of fresh spinach thrice weekly. The effects of water availability were examined in Experiment 2 by housing adult males in long day length conditions for 10 weeks with ad lib or restricted (50% of ad lib) water availability. Neither photoperiod nor availability of green plant food significantly affected reproductive function in male California mice, although animals in long days with green food supplements displayed elevation of some reproductive organ masses. Short days did not suppress plasma LH or prolactin levels. Male P. californicus provide extensive care of the young during the short days of winter. The absence of photoperiod-induced changes in prolactin levels is consistent with the observation that elevated plasma prolactin titers are associated with male parental care in this species. In contrast, water restriction (simulated summer drought) reduced reproductive organ masses, as well as plasma levels of prolactin, and may act as an environmental cue to terminate breeding. Thus, water availability may regulate breeding in this species independently of photoperiod and food availability.


1995 - Learned conditioned immunosuppression is associated with increased risk of chemically-induced tumors. [Articolo su rivista]
Blom, Johanna Maria Catharina; Tamarkin, L; Shiber, Jr; Nelson, Rj
abstract

Based on the hypothesis that certain aspects of the CNS and immune system interact and that altered immune function affects carcinogenesis, an animal model was developed to examine the effects of learned immunosuppression on the development of a chemically induced tumor. In two experiments, we evaluated whether mice, for which immunosuppression was associated with a neutral (conditioned) stimulus, would exhibit an increased susceptibility to tumor development upon reexposure to the conditioned stimulus, as compared to nonconditioned and control animals. A taste aversion conditioning paradigm, based on classical conditioning techniques, was employed to suppress immune function using the cytotoxic and immunosuppressive drug cyclophosphamide (CY) as the unconditioned stimulus and consequently increase the risk of chemically induced tumorigenesis. CY (100 mg/kg, intraperitoneal) was paired with saccharin in the drinking water (0.1%) of adult female mice (CF-1). Conditioned mice were exposed to saccharin twice in the absence of CY, on days 4 and 7 after the first exposure (day 1). All mice were injected with the chemical carcinogen 9,10-dimethylbenzanthracene (DMBA, 50 mg/kg, subcutaneous) on day 4 of conditioning. Two subsequent exposures to saccharin alone substantially increased the risk of developing DMBA-induced tumors (ranging from 83-91%), as compared to control animals (36%) that had not received this pairing. Mice that received all agents (i.e., CY, DMBA, and saccharin) in a slightly different order did not display elevated tumor incidence. Three separate exposures to CY also significantly increased the number of animals developing tumors in response to the carcinogen (75%). Mice were observed for at least 8 weeks after conditioning


1995 - Photoperiodic effects on steroid negative feedback in female prairie voles (Microtus ochrogaster). [Articolo su rivista]
Moffatt, Ca; Gerber, Jm; Blom, Johanna Maria Catharina; Kriegsfield, Lj; Nelson, Rj
abstract

Breeding in prairie voles is mainly restricted to the autumn and winter of most years. The organization of estrus in female prairie voles is unusual because behavioral estrus is induced by chemosensory stimuli from the urine of adult conspecific males. Isolated females exhibit undetectable levels of estradiol and never display estrous behavior, yet exposure to male urine causes a cascade of endocrine changes that evoke estrogen secretion from the ovaries and estrous behavior within 24 hr. In the prairie vole, the extreme dependence of estrus on chemosensory stimuli raises the possibility that their ovaries may be less prominent in the regulation of gonadotropin secretion than in species with more endogenously organized estrous cycles. The present study examined the contribution of the ovaries in luteinizing hormone (LH) regulation in prairie voles. Females were maintained for 9 weeks in either long (LD 16:8) or short (LD 8:16) photoperiodic conditions, a blood sample was obtained, and then animals were either ovariectomized or received a sham procedure. Another blood sample was obtained a week later and assayed for serum LH. Blood serum LH levels were significantly reduced in short-day voles, compared to long-day animals. After ovariectomy both long-day and short-day voles exhibited equivalent elevations in LH levels. This study provides evidence that photoperiod is measured in female voles and the ovaries appear to produce sufficient steroids to suppress LH release.


1994 - Anti-idiotypic antibodies mimick structural and functional properties of IL-1β in its interaction with type I IL-1R. [Articolo su rivista]
Soprano, E; Vogo, E; Verani, A; Blom, Johanna Maria Catharina; Siccardi, A; Vercelli, D. VIALE G.
abstract

We obtained affinity-purified polyclonal anti-id antibodies against mAb MhC1 and BrhC3, which recognize amino acids 133-147 at the N-terminus of mature human IL-1 beta. mAb MhC1 and BrhC3 have been shown to inhibit binding of IL-1 beta to type I IL-1R, and to neutralize IL-1 beta bioactivity in a number of in vitro assays. We show that affinity-purified antibodies against the MhC1 and BrhC3 idiotypes specifically bind to type I IL-1 beta IL-1R and that this binding is inhibited by both IL-1 beta and IL-1ra; anti-id antibodies were also able to trigger IL-1R-dependent events, such as IL-8 secretion by human skin fibroblasts and pyrogenic effect after injection in mice. These anti-id antibodies, therefore, behave as structural and functional "images" of IL-1 beta, both in vivo and in vitro. These data indicate the idiotypic strategy as a powerful tool to study the fine specificity of receptor-ligand interactions. Moreover, this is, to our knowledge, the first report showing that the "internal image" of a cytokine can be active in vivo


1994 - Day length affects immune cell numbers in deer mice: Interactions with age, sex, and prenatal photoperiod [Articolo su rivista]
Blom, J. M. C.; Gerber, J. M.; Nelson, R. J.
abstract

The extent to which day length affects immune function was examined in the present study. Three goals were pursued: 1) to confirm and extend the observation that the immune systems of adult deer mice (Peromyscus maniculatus) are responsive to changes in photoperiod, 2) to examine the development of the photoperiod-associated changes in immune function, and 3) to discover whether photoperiodic information transmitted to the young during gestation influences immune function. In experiment 1, adult mice housed in short days had higher white blood cell and lymphocyte numbers than their long-day cohorts. Red blood cell and differential cell counts did not differ between long- and short-day animals. No sex differences were observed in the pattern of immune responses to photoperiod. The effect of photoperiod on immune cells in prepubertal animals was examined in experiment 2; a similar pattern of results was obtained as that for experiment 1, suggesting that the photoperiodic effect on the immune system is not mediated by sex steroid hormones. Prenatal and postnatal photoperiodic effects on immune cells were examined in experiment 3; pups gestated in one day length were cross-fostered to mothers in the same day length conditions or to mothers maintained in the alternative day length. The results of experiment 3 suggested that photoperiodic information transmitted from the mother to the young in utero subsequently affected immune systems of the pups. Animals gestated in short day lengths displayed higher immune status throughout life than mice gestated in long days. These results are discussed from an adaptive functional perspective.


1994 - Day length affects immune cell numbers in deer mice: The influence of age, sex, and in utero photoperiodic history [Articolo su rivista]
Blom, Johanna Maria Catharina; Gerber, Jm; Nelson, Rj
abstract

The extent to which day length affects immune function was examined in the present study. Three goals were pursued: 1) to confirm and extend the observation that the immune systems of adult deer mice (Peromyscus maniculatus) are responsive to changes in photoperiod, 2) to examine the development of the photoperiod-associated changes in immune function, and 3) to discover whether photoperiodic information transmitted to the young during gestation influences immune function. In experiment 1, adult mice housed in short days had higher white blood cell and lymphocyte numbers than their long-day cohorts. Red blood cell and differential cell counts did not differ between long- and short-day animals. No sex differences were observed in the pattern of immune responses to photoperiod. The effect of photoperiod on immune cells in prepubertal animals was examined in experiment 2; a similar pattern of results was obtained as that for experiment 1, suggesting that the photoperiodic effect on the immune system is not mediated by sex steroid hormones. Prenatal and postnatal photoperiodic effects on immune cells were examined in experiment 3; pups gestated in one day length were cross-fostered to mothers in the same day length conditions or to mothers maintained in the alternative day length. The results of experiment 3 suggested that photoperiodic information transmitted from the mother to the young in utero subsequently affected immune systems of the pups. Animals gestated in short day lengths displayed higher immune status throughout life than mice gestated in long days. These results are discussed from an adaptive functional perspective.


1994 - Photoperiodic effects on tumor development and immune function. [Articolo su rivista]
Nelson, Rj; Blom, Johanna Maria Catharina
abstract

Seasonal changes in adaptations associated with winter coping strategies have been frequently studied. Central among the suite of energy-saving, winter-coping strategies is the suspension of reproductive activities. The inhibition of reproduction by nontropical rodents is mediated by daylength changes. Although balanced annual energy budgets are critical, survival and subsequent reproductive success also require avoiding predators, illness, and early death. Because the stressors of winter could lead to suppressed immune function, we hypothesized that animals should have evolved survival strategies involving immunoenhancement. Short daylengths provide a predictive cue to individuals that could be used to enhance immune function in advance of stress-induced immunosuppression. In Experiment 1, adult female deer mice (Peromyscus maniculatus) were housed in either long (LD 16:8) or short (LD 8:16) days for 8 weeks, then injected with the chemical carcinogen 9,10-dimethyl-1,2-benzanthracene (DMBA) dissolved in dimethyl sulfoxide (DMSO) or with the DMSO vehicle alone. Animals were evaluated weekly for 8 weeks after injection. None of the animals treated with DMSO developed tumors in any of the experiments. Nearly 90% of the long-day deer mice injected with DMBA developed squamous cell carcinoma. None of the short-day deer mice injected with DMBA developed tumors. Small lesions developed at the site of injection; short-day females had less severe lesions and healed faster than long-day females. Immunoglobulin G (IgG) response to i.p. injection of sheep red blood cells (SRBC) did not differ photoperiodic conditions. The role of estrogens in the photoperiodic responses was evaluated in Experiment 2: Ovariectomized or sham-ovariectomized deer mice received estradiol benzoate replacement therapy or a control procedure in long daylengths for 8 weeks prior to injection of DMBA or DMSO, then were monitored for 8 additional weeks. Females treated with DMBA developed tumors at the same rate, regardless of estrogen manipulation. Estrogen did not affect healing rates. In Experiment 3, female deer mice were injected with a slurry of microspheres that either contained bromocriptine or were empty. Suppression of prolactin with bromocriptine resulted in a decrease of tumor incidence from 55.6% to 24% in long-day females 8 weeks after injection with DMBA. Healing rates were not affected by prolactin manipulations. Silastic capsules that were filled with either melatonin or cholesterol were implanted into long-day female deer mice in Experiment 4; 8 weeks later, females received an injection of either DMBA or DMSO, then were monitored for 8 weeks.(


1993 - 6-Methoxy-2-Benzoxazolinone and photoperiod: prenatal and postnatal influences on reproductive development in prairie voles (Microtus ochrogaster). [Articolo su rivista]
Nelson, Rj; Blom, Johanna Maria Catharina
abstract

The effects of photoperiod and 6-methoxy-2-benzoxazolinone (6-MBOA) on the gonadal development of prairie voles was studied when this plant compound was available to pups in utero, during nursing, or postweaning. In part 1, pregnant voles exposed to long or short day lengths were fed food in which 6-MBOA was present (50 μg of 6-MBOA/g food) or absent prior to the birth of their young; all of these dams received a diet that lacked 6-MBOA after the pups were born. Other females were fed food without 6-MBOA throughout pregnancy, but received one of the diets during lactation. Short days inhibited reproductive development in male offspring, affected pup survival, and enhanced pelage development. Postnatal exposure to 6-MBOA did not affect the reproductive function of males. In contrast, prenatal exposure to 6-MBOA accelerated reproductive development among short-day males. Prenatal exposure to 6-MBOA did not affect survival of short-day males, but reduced survival of long-day pups. Prenatal 6-MBOA treatment affected the sex ratio of pups that survived until weaning (13:21; male:female) and of pups that died prior to weaning (26:5). In contrast, photoperiod did not affect reproductive function in female voles. Although reproductive function appears to be uncoupled from photoperiodic regulation, female prairie voles processed photoperiodic information; pelage development was enhanced among short-day females. In part II, breeding pairs were exposed to long or short days and fed food devoid of 6-MBOA prior to the birth of the young. On the day of birth, and for the following 3 weeks, either 6-MBOA-free or 6-MBOA-enriehed food was provided. After weaning, pups received their parents type of food until autopsy 3 or 7 weeks later. Again, photoperiod affected male, but not female, reproductive function. No consistent pattern of results from postnatal exposure to 6-MBOA was discerned for either males or females. Acceleration of reproductive function among short-day males because of prenatal influences may, be involved in the rapid rate of sexual maturation observed prior to peak population densities of microtine rodents. Because males of this species induce females into estrus, male prairie voles may depend on environmental cues to regulate reproductive function, while females may respond only to males. The physiological and ecological implications of these data are discussed


1992 - Photoperiod influences the critical caloric intake necessary to maintain reproduction among male deer mice (Peromyscus maniculatus). [Articolo su rivista]
Nelson, R; Kita, M; Blom, Johanna Maria Catharina; RHYNE GREY, J.
abstract

The concept of critical day length is well established among rodents; reproductive function Is maintained when day lengths are greater than some specific threshold. In addition to day length cues, seasonal breeding in deer mice can also be regulated by food availability. The caloric threshold necessary to support reproduction remains unspecified for seasonally breeding rodents. The present study examined the interaction between photoperiod and food availability on reproductive function in adult male deer mice (Peromyscus maniculatus). A critical caloric intake profile was constructed in long (16L:8D) and short (8L:16D) photoperiods; groups of deer mice in both photoperiods either received food ad libitum or 90, 80, or 70% of their individual ad libitum food intake for 10 wk. At autopsy, paired testes, epididymides, and seminal vesicles were removed and weighed. Body mass, total body fat, and total body water contents were also obtained. Short, as compared to long, day lengths inhibited the reproductive systems of male deer mice. However, food consumption interacted with photoperiod to affect reproductive function. Significant reductions in reproductive organ size as well as spermatogenic activity were observed among short-day mice after a 10% reduction in ad libitum food intake. Long-day animals required a 20% reduction in caloric intake to depress reproductive function. Body mass and total body water content were generally unaffected by either photoperiod or food consumption. Total body fat content was reduced in short- as compared to long-day mice. Individual reproductive responsiveness to short days increased as food availability decreased. Reproductive organ mass and spermatogenic activity were comparable between longday males restricted to 70% of their ad lib food intake and short-day males fed ad libitum; i.e., both groups exhibited significant reproductive regression as compared to long-day males with unrestricted access to food. However, few of these ‘regressed’ males were aspermic. In contrast, the inhibitory effects of short day lengths plus 30% restricted food intake caused virtually all mice to stop spermatogenesis. Taken together, these results confirm that short photoperiods cause statistically significant reduction in gonadal size and sperm production; however, food availability may determine whether the reduction in sperm number is functionally significant.