TY - JOUR A1 - Gorlova, Anna A1 - Svirin, Evgeniy A1 - Pavlov, Dmitrii A1 - Cespuglio, Raymond A1 - Proshin, Andrey A1 - Schroeter, Careen A. A1 - Lesch, Klaus-Peter A1 - Strekalova, Tatyana T1 - Understanding the role of oxidative stress, neuroinflammation and abnormal myelination in excessive aggression associated with depression: recent input from mechanistic studies JF - International Journal of Molecular Sciences N2 - Aggression and deficient cognitive control problems are widespread in psychiatric disorders, including major depressive disorder (MDD). These abnormalities are known to contribute significantly to the accompanying functional impairment and the global burden of disease. Progress in the development of targeted treatments of excessive aggression and accompanying symptoms has been limited, and there exists a major unmet need to develop more efficacious treatments for depressed patients. Due to the complex nature and the clinical heterogeneity of MDD and the lack of precise knowledge regarding its pathophysiology, effective management is challenging. Nonetheless, the aetiology and pathophysiology of MDD has been the subject of extensive research and there is a vast body of the latest literature that points to new mechanisms for this disorder. Here, we overview the key mechanisms, which include neuroinflammation, oxidative stress, insulin receptor signalling and abnormal myelination. We discuss the hypotheses that have been proposed to unify these processes, as many of these pathways are integrated for the neurobiology of MDD. We also describe the current translational approaches in modelling depression, including the recent advances in stress models of MDD, and emerging novel therapies, including novel approaches to management of excessive aggression, such as anti-diabetic drugs, antioxidant treatment and herbal compositions. KW - major depressive disorder (MDD) KW - aggression KW - neuroinflammation KW - oxidative stress KW - insulin receptor KW - myelination Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304917 SN - 1422-0067 VL - 24 IS - 2 ER - TY - JOUR A1 - Strekalova, Tatyana A1 - Veniaminova, Ekaterina A1 - Svirin, Evgeniy A1 - Kopeikina, Ekaterina A1 - Veremeyko, Tatyana A1 - Yung, Amanda W. Y. A1 - Proshin, Andrey A1 - Tan, Shawn Zheng Kai A1 - Khairuddin, Sharafuddin A1 - Lim, Lee Wei A1 - Lesch, Klaus-Peter A1 - Walitza, Susanne A1 - Anthony, Daniel C. A1 - Ponomarev, Eugene D. T1 - Sex-specific ADHD-like behaviour, altered metabolic functions, and altered EEG activity in sialyltransferase ST3GAL5-deficient mice JF - Biomolecules N2 - A deficiency in GM3-derived gangliosides, resulting from a lack of lactosylceramide-alpha-2,3-sialyltransferase (ST3GAL5), leads to severe neuropathology, including epilepsy and metabolic abnormalities. Disruption of ganglioside production by this enzyme may also have a role in the development of neuropsychiatric disorders. ST3Gal5 knock-out (St3gal5\(^{−/−}\)) mice lack a-, b-, and c-series gangliosides, but exhibit no overt neuropathology, possibly owing to the production of compensatory 0-series glycosphingolipids. Here, we sought to investigate the possibility that St3gal5\(^{−/−}\) mice might exhibit attention-deficit/hyperactivity disorder (ADHD)-like behaviours. In addition, we evaluated potential metabolic and electroencephalogram (EEG) abnormalities. St3gal5\(^{−/−}\) mice were subjected to behavioural testing, glucose tolerance tests, and the levels of expression of brain and peripheral A and B isoforms of the insulin receptor (IR) were measured. We found that St3gal5\(^{−/−}\) mice exhibit locomotor hyperactivity, impulsivity, neophobia, and anxiety-like behavior. The genotype also altered blood glucose levels and glucose tolerance. A sex bias was consistently found in relation to body mass and peripheral IR expression. Analysis of the EEG revealed an increase in amplitude in St3gal5\(^{−/−}\) mice. Together, St3gal5\(^{−/−}\) mice exhibit ADHD-like behaviours, altered metabolic and EEG measures providing a useful platform for better understanding of the contribution of brain gangliosides to ADHD and associated comorbidities. KW - lactosylceramide alpha-2,3-sialyltransferase (ST3GAL5) KW - attention-deficit/hyperactivity disorder (ADHD) KW - insulin receptor (IR) KW - sex differences KW - electroencephalogram (EEG) KW - mice Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250071 SN - 2218-273X VL - 11 IS - 12 ER - TY - JOUR A1 - Svirin, Evgeniy A1 - Veniaminova, Ekaterina A1 - Costa-Nunes, João Pedro A1 - Gorlova, Anna A1 - Umriukhin, Aleksei A1 - Kalueff, Allan V. A1 - Proshin, Andrey A1 - Anthony, Daniel C. A1 - Nedorubov, Andrey A1 - Tse, Anna Chung Kwan A1 - Walitza, Susanne A1 - Lim, Lee Wei A1 - Lesch, Klaus-Peter A1 - Strekalova, Tatyana T1 - Predation stress causes excessive aggression in female mice with partial genetic inactivation of tryptophan hydroxylase-2: evidence for altered myelination-related processes JF - Cells N2 - The interaction between brain serotonin (5-HT) deficiency and environmental adversity may predispose females to excessive aggression. Specifically, complete inactivation of the gene encoding tryptophan hydroxylase-2 (Tph2) results in the absence of neuronal 5-HT synthesis and excessive aggressiveness in both male and female null mutant (Tph2\(^{−/−}\)) mice. In heterozygous male mice (Tph2\(^{+/−}\)), there is a moderate reduction in brain 5-HT levels, and when they are exposed to stress, they exhibit increased aggression. Here, we exposed female Tph2\(^{+/−}\) mice to a five-day rat predation stress paradigm and assessed their emotionality and social interaction/aggression-like behaviors. Tph2\(^{+/−}\) females exhibited excessive aggression and increased dominant behavior. Stressed mutants displayed altered gene expression of the 5-HT receptors Htr1a and Htr2a, glycogen synthase kinase-3 β (GSK-3β), and c-fos as well as myelination-related transcripts in the prefrontal cortex: myelin basic protein (Mbp), proteolipid protein 1 (Plp1), myelin-associated glycoprotein (Mag), and myelin oligodendrocyte glycoprotein (Mog). The expression of the plasticity markers synaptophysin (Syp) and cAMP response element binding protein (Creb), but not AMPA receptor subunit A2 (GluA2), were affected by genotype. Moreover, in a separate experiment, naïve female Tph2\(^{+/−}\) mice showed signs of enhanced stress resilience in the modified swim test with repeated swimming sessions. Taken together, the combination of a moderate reduction in brain 5-HT with environmental challenges results in behavioral changes in female mice that resemble the aggression-related behavior and resilience seen in stressed male mutants; additionally, the combination is comparable to the phenotype of null mutants lacking neuronal 5-HT. Changes in myelination-associated processes are suspected to underpin the molecular mechanisms leading to aggressive behavior. KW - tryptophan hydroxylase-2 (Tph2) KW - female aggression KW - 5-HT receptors KW - glycogen synthase kinase-3 β (GSK-3β) KW - myelination KW - predation stress Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267250 SN - 2073-4409 VL - 11 IS - 6 ER - TY - JOUR A1 - Veniaminova, Ekaterina A1 - Cespuglio, Raymond A1 - Chernukha, Irina A1 - Schmitt-Boehrer, Angelika G. A1 - Morozov, Sergey A1 - Kalueff, Allan V. A1 - Kuznetsova, Oxana A1 - Anthony, Daniel C. A1 - Lesch, Klaus-Peter A1 - Strekalova, Tatyana T1 - Metabolic, Molecular, and Behavioral Effects of Western Diet in Serotonin Transporter-Deficient Mice: Rescue by Heterozygosity? JF - Frontiers in Neuroscience N2 - Reduced function of the serotonin transporter (SERT) is associated with increased susceptibility to anxiety and depression and with type-2 diabetes, which is especially true in older women. Preference for a “Western diet” (WD), enriched with saturated fat, cholesterol, and sugars, may aggravate these conditions. In previous studies, decreased glucose tolerance, central and peripheral inflammation, dyslipidemia, emotional, cognitive, and social abnormalities were reported in WD-fed young female mice. We investigated the metabolic, molecular, and behavioral changes associated with a 3-week-long dietary regime of either the WD or control diet in 12-month-old female mice with three different Sert genotypes: homozygous (Slc6a4) gene knockout (Sert\(^{−/−}\): KO), heterozygous (Sert\(^{+/−}\): HET), or wild-type mice (Sert\(^{+/+}\): WT). In the WT-WD and KO-WD groups, but not in HET-WD-fed mice, most of changes induced by the WD paralleled those found in the younger mice, including brain overexpression of inflammatory marker Toll-like receptor 4 (Tlr4) and impaired hippocampus-dependent performance in the marble test. However, the 12-month-old female mice became obese. Control diet KO mice exhibited impaired hippocampal-dependent behaviors, increased brain expression of the serotonin receptors Htr2c and Htr1b, as well as increased Tlr4 and mitochondrial regulator, peroxisome proliferator-activated receptor gamma-coactivator-1a (Ppargc1a). Paradoxically, these, and other changes, were reversed in KO-WD mutants, suggesting a complex interplay between Sert deficiency and metabolic factors as well as potential compensatory molecular mechanisms that might be disrupted by the WD exposure. Most, but not all, of the changes in gene expression in the brain and liver of KO mice were not exhibited by the HET mice fed with either diet. Some of the WD-induced changes were similar in the KO-WD and HET-WD-fed mice, but the latter displayed a “rescued” phenotype in terms of diet-induced abnormalities in glucose tolerance, neuroinflammation, and hippocampus-dependent performance. Thus, complete versus partial Sert inactivation in aged mice results in distinct metabolic, molecular, and behavioral consequences in response to the WD. Our findings show that Sert\(^{+/−}\) mice are resilient to certain environmental challenges and support the concept of heterosis as evolutionary adaptive mechanism. KW - Sert-deficient mice KW - Western diet KW - aging KW - glucose tolerance KW - Toll-like receptor 4 (TLR4) KW - serotonin receptors KW - obesity KW - heterosis Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199813 SN - 1662-453X VL - 14 ER - TY - JOUR A1 - Couch, Yvonne A1 - Trofimov, Alexander A1 - Markova, Natalyia A1 - Nikolenko, Vladimir A1 - Steinbusch, Harry W. A1 - Chekhonin, Vladimir A1 - Schroeter, Careen A1 - Lesch, Klaus-Peter A1 - Anthony, Daniel C. A1 - Strekalova, Tatyana T1 - Low-dose lipopolysaccharide (LPS) inhibits aggressive and augments depressive behaviours in a chronic mild stress model in mice JF - Journal of Neuroinflammation N2 - Background Aggression, hyperactivity, impulsivity, helplessness and anhedonia are all signs of depressive-like disorders in humans and are often reported to be present in animal models of depression induced by stress or by inflammatory challenges. However, chronic mild stress (CMS) and clinically silent inflammation, during the recovery period after an infection, for example, are often coincident, but comparison of the behavioural and molecular changes that underpin CMS vs a mild inflammatory challenge and impact of the combined challenge is largely unexplored. Here, we examined whether stress-induced behavioural and molecular responses are analogous to lipopolysaccharide (LPS)-induced behavioural and molecular effects and whether their combination is adaptive or maladaptive. Methods Changes in measures of hedonic sensitivity, helplessness, aggression, impulsivity and CNS and systemic cytokine and 5-HT-system-related gene expression were investigated in C57BL/6J male mice exposed to chronic stress alone, low-dose LPS alone or a combination of LPS and stress. Results When combined with a low dose of LPS, chronic stress resulted in an enhanced depressive-like phenotype but significantly reduced manifestations of aggression and hyperactivity. At the molecular level, LPS was a strong inducer of TNFα, IL-1β and region-specific 5-HT2A mRNA expression in the brain. There was also increased serum corticosterone as well as increased TNFα expression in the liver. Stress did not induce comparable levels of cytokine expression to an LPS challenge, but the combination of stress with LPS reduced the stress-induced changes in 5-HT genes and the LPS-induced elevated IL-1β levels. Conclusions It is evident that when administered independently, both stress and LPS challenges induced distinct molecular and behavioural changes. However, at a time when LPS alone does not induce any overt behavioural changes per se, the combination with stress exacerbates depressive and inhibits aggressive behaviours. KW - SERT KW - Chronic stress KW - LPS KW - Aggressive behaviour KW - S-HT KW - Cytokines Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165676 VL - 13 IS - 108 ER - TY - JOUR A1 - Gutknecht, Lise A1 - Popp, Sandy A1 - Waider, Jonas A1 - Sommerlandt, Frank M. J. A1 - Göppner, Corinna A1 - Post, Antonia A1 - Reif, Andreas A1 - van den Hove, Daniel A1 - Strekalova, Tatyana A1 - Schmitt, Angelika A1 - Colaςo, Maria B. N. A1 - Sommer, Claudia A1 - Palme, Rupert A1 - Lesch, Klaus-Peter T1 - Interaction of brain 5-HT synthesis deficiency, chronic stress and sex differentially impact emotional behavior in Tph2 knockout mice JF - Psychopharmacology N2 - Rationale While brain serotonin (5-HT) function is implicated in gene-by-environment interaction (GxE) impacting the vulnerability-resilience continuum in neuropsychiatric disorders, it remains elusive how the interplay of altered 5-HT synthesis and environmental stressors is linked to failure in emotion regulation. Objective Here, we investigated the effect of constitutively impaired 5-HT synthesis on behavioral and neuroendocrine responses to unpredictable chronic mild stress (CMS) using a mouse model of brain 5-HT deficiency resulting from targeted inactivation of the tryptophan hydroxylase-2 (Tph2) gene. Results Locomotor activity and anxiety- and depression-like behavior as well as conditioned fear responses were differentially affected by Tph2 genotype, sex, and CMS. Tph2 null mutants (Tph2\(^{−/−}\)) displayed increased general metabolism, marginally reduced anxiety- and depression-like behavior but strikingly increased conditioned fear responses. Behavioral modifications were associated with sex-specific hypothalamic-pituitary-adrenocortical (HPA) system alterations as indicated by plasma corticosterone and fecal corticosterone metabolite concentrations. Tph2\(^{−/−}\) males displayed increased impulsivity and high aggressiveness. Tph2\(^{−/−}\) females displayed greater emotional reactivity to aversive conditions as reflected by changes in behaviors at baseline including increased freezing and decreased locomotion in novel environments. However, both Tph2\(^{−/−}\) male and female mice were resilient to CMS-induced hyperlocomotion, while CMS intensified conditioned fear responses in a GxE-dependent manner. Conclusions Our results indicate that 5-HT mediates behavioral responses to environmental adversity by facilitating the encoding of stress effects leading to increased vulnerability for negative emotionality. KW - Serotonin KW - Tryptophan hydroxylase-2 (Tph2) KW - chronic stress KW - gene-by-environment interaction KW - anxiety KW - fear KW - depression KW - aggression Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-154586 VL - 232 SP - 2429 EP - 2441 ER - TY - JOUR A1 - Strekalova, Tatyana A1 - Markova, Nataliia A1 - Shevtsova, Elena A1 - Zubareva, Olga A1 - Bakhmet, Anastassia A1 - Steinbusch, Harry M. A1 - Bachurin, Sergey A1 - Lesch, Klaus-Peter T1 - Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test JF - Neural Plasticity N2 - While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome. KW - mice KW - swim test Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147379 VL - 2016 ER - TY - JOUR A1 - de Munter, Johannes A1 - Pavlov, Dmitrii A1 - Gorlova, Anna A1 - Sicker, Michael A1 - Proshin, Andrey A1 - Kalueff, Allan V. A1 - Svistunov, Andrey A1 - Kiselev, Daniel A1 - Nedorubov, Andrey A1 - Morozov, Sergey A1 - Umriukhin, Aleksei A1 - Lesch, Klaus-Peter A1 - Strekalova, Tatyana A1 - Schroeter, Careen A. T1 - Increased Oxidative Stress in the Prefrontal Cortex as a Shared Feature of Depressive- and PTSD-Like Syndromes: Effects of a Standardized Herbal Antioxidant JF - Frontiers in Nutrition N2 - Major depression (MD) and posttraumatic stress disorder (PTSD) share common brain mechanisms and treatment strategies. Nowadays, the dramatically developing COVID-19 situation unavoidably results in stress, psychological trauma, and high incidence of MD and PTSD. Hence, the importance of the development of new treatments for these disorders cannot be overstated. Herbal medicine appears to be an effective and safe treatment with fewer side effects than classic pharmaca and that is affordable in low-income countries. Currently, oxidative stress and neuroinflammation attract increasing attention as important mechanisms of MD and PTSD. We investigated the effects of a standardized herbal cocktail (SHC), an extract of clove, bell pepper, basil, pomegranate, nettle, and other plants, that was designed as an antioxidant treatment in mouse models of MD and PTSD. In the MD model of “emotional” ultrasound stress (US), mice were subjected to ultrasound frequencies of 16–20 kHz, mimicking rodent sounds of anxiety/despair and “neutral” frequencies of 25–45 kHz, for three weeks and concomitantly treated with SHC. US-exposed mice showed elevated concentrations of oxidative stress markers malondialdehyde and protein carbonyl, increased gene and protein expression of pro-inflammatory cytokines interleukin (IL)-1β and IL-6 and other molecular changes in the prefrontal cortex as well as weight loss, helplessness, anxiety-like behavior, and neophobia that were ameliorated by the SHC treatment. In the PTSD model of the modified forced swim test (modFST), in which a 2-day swim is followed by an additional swim on day 5, mice were pretreated with SHC for 16 days. Increases in the floating behavior and oxidative stress markers malondialdehyde and protein carbonyl in the prefrontal cortex of modFST-mice were prevented by the administration of SHC. Chromatography mass spectrometry revealed bioactive constituents of SHC, including D-ribofuranose, beta-D-lactose, malic, glyceric, and citric acids that can modulate oxidative stress, immunity, and gut and microbiome functions and, thus, are likely to be active antistress elements underlying the beneficial effects of SHC. Significant correlations of malondialdehyde concentration in the prefrontal cortex with altered measures of behavioral despair and anxiety-like behavior suggest that the accumulation of oxidative stress markers are a common biological feature of MD and PTSD that can be equally effectively targeted therapeutically with antioxidant therapy, such as the SHC investigated here. KW - antioxidant nutrients KW - oxidative stress KW - depression KW - post-traumatic stress disorder KW - pro-inflammatory cytokines KW - prefrontal cortex KW - forced swimming KW - mice Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236326 SN - 2296-861X VL - 8 ER - TY - JOUR A1 - Schapovalova, Olesia A1 - Gorlova, Anna A1 - de Munter, Johannes A1 - Sheveleva, Elisaveta A1 - Eropkin, Mikhail A1 - Gorbunov, Nikita A1 - Sicker, Michail A1 - Umriukhin, Aleksei A1 - Lyubchyk, Sergiy A1 - Lesch, Klaus-Peter A1 - Strekalova, Tatyana A1 - Schroeter, Careen A. T1 - Immunomodulatory effects of new phytotherapy on human macrophages and TLR4- and TLR7/8-mediated viral-like inflammation in mice JF - Frontiers in Medicine N2 - Background While all efforts have been undertaken to propagate the vaccination and develop remedies against SARS-CoV-2, no satisfactory management of this infection is available yet. Moreover, poor availability of any preventive and treatment measures of SARS-CoV-2 in economically disadvantageous communities aggravates the course of the pandemic. Here, we studied a new immunomodulatory phytotherapy (IP), an extract of blackberry, chamomile, garlic, cloves, and elderberry as a potential low-cost solution for these problems given the reported efficacy of herbal medicine during the previous SARS virus outbreak. Methods The key feature of SARS-CoV-2 infection, excessive inflammation, was studied in in vitro and in vivo assays under the application of the IP. First, changes in tumor-necrosis factor (TNF) and lnteurleukin-1 beta (IL-1β) concentrations were measured in a culture of human macrophages following the lipopolysaccharide (LPS) challenge and treatment with IP or prednisolone. Second, chronically IP-pre-treated CD-1 mice received an agonist of Toll-like receptors (TLR)-7/8 resiquimod and were examined for lung and spleen expression of pro-inflammatory cytokines and blood formula. Finally, chronically IP-pre-treated mice challenged with LPS injection were studied for “sickness” behavior. Additionally, the IP was analyzed using high-potency-liquid chromatography (HPLC)-high-resolution-mass-spectrometry (HRMS). Results LPS-induced in vitro release of TNF and IL-1β was reduced by both treatments. The IP-treated mice displayed blunted over-expression of SAA-2, ACE-2, CXCL1, and CXCL10 and decreased changes in blood formula in response to an injection with resiquimod. The IP-treated mice injected with LPS showed normalized locomotion, anxiety, and exploration behaviors but not abnormal forced swimming. Isoquercitrin, choline, leucine, chlorogenic acid, and other constituents were identified by HPLC-HRMS and likely underlie the IP immunomodulatory effects. Conclusions Herbal IP-therapy decreases inflammation and, partly, “sickness behavior,” suggesting its potency to combat SARS-CoV-2 infection first of all via its preventive effects. KW - toll-like receptors KW - SARS-CoV-2 KW - inflammation KW - pro-inflammatory cytokines KW - mice Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286301 SN - 2296-858X VL - 9 ER - TY - JOUR A1 - Weidner, Magdalena T. A1 - Lardenoije, Roy A1 - Eijssen, Lars A1 - Mogavero, Floriana A1 - De Groodt, Lilian P. M. T. A1 - Popp, Sandy A1 - Palme, Rupert A1 - Förstner, Konrad U. A1 - Strekalova, Tatyana A1 - Steinbusch, Harry W. M. A1 - Schmitt-Böhrer, Angelika G. A1 - Glennon, Jeffrey C. A1 - Waider, Jonas A1 - van den Hove, Daniel L. A. A1 - Lesch, Klaus-Peter T1 - Identification of cholecystokinin by genome-wide profiling as potential mediator of serotonin-dependent behavioral effects of maternal separation in the amygdala JF - Frontiers in Neuroscience N2 - Converging evidence suggests a role of serotonin (5-hydroxytryptamine, 5-HT) and tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme of 5-HT synthesis in the brain, in modulating long-term, neurobiological effects of early-life adversity. Here, we aimed at further elucidating the molecular mechanisms underlying this interaction, and its consequences for socio-emotional behaviors, with a focus on anxiety and social interaction. In this study, adult, male Tph2 null mutant (Tph2\(^{-/-}\)) and heterozygous (Tph2\(^{+/-}\)) mice, and their wildtype littermates (Tph2\(^{+/+}\)) were exposed to neonatal, maternal separation (MS) and screened for behavioral changes, followed by genome-wide RNA expression and DNA methylation profiling. In Tph2\(^{-/-}\) mice, brain 5-HT deficiency profoundly affected socio-emotional behaviors, i.e., decreased avoidance of the aversive open arms in the elevated plus-maze (EPM) as well as decreased prosocial and increased rule breaking behavior in the resident-intruder test when compared to their wildtype littermates. Tph2\(^{+/-}\) mice showed an ambiguous profile with context-dependent, behavioral responses. In the EPM they showed similar avoidance of the open arm but decreased prosocial and increased rule breaking behavior in the resident-intruder test when compared to their wildtype littermates. Notably, MS effects on behavior were subtle and depended on the Tph2 genotype, in particular increasing the observed avoidance of EPM open arms in wildtype and Tph2\(^{+/-}\) mice when compared to their Tph2\(^{-/-}\) littermates. On the genomic level, the interaction of Tph2 genotype with MS differentially affected the expression of numerous genes, of which a subset showed an overlap with DNA methylation profiles at corresponding loci. Remarkably, changes in methylation nearby and expression of the gene encoding cholecystokinin, which were inversely correlated to each other, were associated with variations in anxiety-related phenotypes. In conclusion, next to various behavioral alterations, we identified gene expression and DNA methylation profiles to be associated with TPH2 inactivation and its interaction with MS, suggesting a gene-by-environment interaction-dependent, modulatory function of brain 5-HT availability. KW - serotonin KW - maternal separation KW - mouse KW - emotional behavior KW - DNA methylation KW - RNA expression Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201340 VL - 13 ER -