1 5752 137 SOCIAL ISOLATION AND SOCIAL SUPPORT AT ADULTHOOD AFFECT EPIGENETIC MECHANISMS, BRAIN-DERIVED NEUROTROPHIC FACTOR LEVELS AND BEHAVIOR OF CHRONICALLY STRESSED RATS. EPIGENETIC MODULATION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) PROVIDES ONE POSSIBLE EXPLANATION FOR THE DYSFUNCTIONS INDUCED BY STRESS, SUCH AS PSYCHIATRIC DISORDERS AND COGNITIVE DECLINE. INTERESTINGLY, SOCIAL SUPPORT CAN BE PROTECTIVE AGAINST SOME OF THESE EFFECTS, BUT THE MECHANISMS OF SOCIAL BUFFERING ARE POORLY UNDERSTOOD. CONVERSELY, EARLY ISOLATION EXACERBATES THE RESPONSES TO STRESSORS, ALTHOUGH ITS EFFECTS IN ADULTHOOD REMAIN UNCLEAR. THIS STUDY INVESTIGATED THE EFFECTS OF SOCIAL ISOLATION AND SOCIAL BUFFERING ON HIPPOCAMPAL EPIGENETIC MECHANISMS, BDNF LEVELS AND BEHAVIORAL RESPONSES OF CHRONICALLY STRESSED YOUNG ADULT RATS. MALE WISTAR RATS (3 MONTHS) WERE ASSIGNED TO ACCOMPANIED (PAIRED) OR ISOLATED HOUSING. AFTER ONE-MONTH HALF OF EACH GROUP WAS SUBMITTED TO A CHRONIC UNPREDICTABLE STRESS (CUS) PROTOCOL FOR 18 DAYS. AMONG ACCOMPANIED ANIMALS, ONLY ONE WAS EXPOSED TO STRESS. BEHAVIORAL ANALYSIS ENCOMPASSED THE OPEN FIELD, PLUS MAZE AND INHIBITORY AVOIDANCE TASKS. HIPPOCAMPAL H3K9 AND H4K12 ACETYLATION, HDAC5 EXPRESSION AND BDNF LEVELS WERE EVALUATED. ISOLATED HOUSING INCREASED HDAC5 EXPRESSION, DECREASED H3K9 AND H4K12 ACETYLATION, REDUCED BDNF LEVELS, AND IMPAIRED LONG-TERM MEMORY. STRESS AFFECTED WEIGHT GAIN, INDUCED ANXIETY-LIKE BEHAVIOR AND DECREASED ACK9H3 LEVELS. INTERACTIONS BETWEEN HOUSING CONDITIONS AND SOCIAL STRESS WERE SEEN ONLY FOR HDAC5 EXPRESSION, WHICH SHOWED A FURTHER INCREASE IN THE ISOLATED + CUS GROUP BUT REMAINED CONSTANT IN ACCOMPANIED ANIMALS. IN CONCLUSION, SOCIAL ISOLATION AT ADULTHOOD INDUCED EPIGENETIC ALTERATIONS AND EXACERBATED THE EFFECTS OF CHRONIC STRESS ON HDAC5. NOTWITHSTANDING, SOCIAL SUPPORT COUNTERACTED THE ADVERSE EFFECTS OF STRESS ON HDAC5 EXPRESSION. 2019 2 578 56 BEHAVIOR, BDNF AND EPIGENETIC MECHANISMS IN RESPONSE TO SOCIAL ISOLATION AND SOCIAL SUPPORT IN MIDDLE AGED RATS EXPOSED TO CHRONIC STRESS. SOCIAL DEPRIVATION CAN BE STRESSFUL FOR GROUP-LIVING MAMMALS. ON THE OTHER HAND, AN AMAZING RESPONSE OF THESE ANIMALS TO STRESS IS SEEKING SOCIAL CONTACT TO GIVE AND RECEIVE JOINT PROTECTION IN THREATENING SITUATIONS. WE EXPLORED THE EFFECTS OF SOCIAL ISOLATION AND SOCIAL SUPPORT ON EPIGENETIC AND BEHAVIORAL RESPONSES TO CHRONIC STRESS. MORE SPECIFICALLY, WE INVESTIGATED THE BEHAVIORAL RESPONSES, CORTICOSTERONE LEVELS, BDNF GENE EXPRESSION, AND MARKERS OF HIPPOCAMPAL EPIGENETIC ALTERATIONS (LEVELS OF H3K9 ACETYLATION AND METHYLATION, H3K27 METHYLATION, HDAC5, DNMT1, AND DNMT3A GENE EXPRESSIONS) IN MIDDLE-AGED ADULT RATS MAINTAINED IN DIFFERENT HOUSING CONDITIONS (ISOLATION OR ACCOMPANIED HOUSING) AND EXPOSED TO THE CHRONIC UNPREDICTABLE STRESS PROTOCOL (CUS). ISOLATION WAS ASSOCIATED WITH DECREASED BASAL LEVELS OF CORTICOSTERONE, IMPAIRED LONG-TERM MEMORY, AND DECREASED EXPRESSION OF THE BDNF GENE, BESIDES ALTERING THE BALANCE OF H3K9 FROM ACETYLATION TO METHYLATION AND INCREASING THE DNMT1 GENE EXPRESSION. THE CUS PROTOCOL DECREASED H3K9 ACETYLATION, BESIDES INCREASING H3K27 METHYLATION AND DNMT1 GENE EXPRESSION, BUT HAD NO SIGNIFICANT EFFECTS ON MEMORY AND BDNF GENE EXPRESSION. INTERESTINGLY, THE EFFECTS OF CUS ON CORTICOSTERONE AND HDAC5 GENE EXPRESSION WERE SEEN ONLY IN ISOLATED ANIMALS, WHEREAS THE EFFECTS OF CUS ON DNMT1 GENE EXPRESSION WERE MORE PRONOUNCED IN ISOLATED THAN ACCOMPANIED ANIMALS. IN CONCLUSION, SOCIAL ISOLATION IN MIDDLE AGE SHOWED BROADER EFFECTS THAN CHRONIC UNPREDICTABLE STRESS ON BEHAVIORAL AND EPIGENETIC ALTERATIONS POTENTIALLY ASSOCIATED WITH DECREASED BDNF EXPRESSION. MOREOVER, SOCIAL SUPPORT PREVENTED THE ADVERSE EFFECTS OF CUS ON HPA AXIS FUNCTIONING, HDAC5, AND DNMT1 GENE EXPRESSIONS. 2023 3 3973 43 LONG-TERM BEHAVIORAL AND NEUROENDOCRINE ALTERATIONS FOLLOWING CHRONIC SOCIAL STRESS IN MICE: IMPLICATIONS FOR STRESS-RELATED DISORDERS. THE PERIOD OF ADOLESCENCE IS CHARACTERIZED BY A HIGH VULNERABILITY TO STRESS AND TRAUMA, WHICH MIGHT RESULT IN LONG-LASTING CONSEQUENCES AND AN INCREASED RISK TO DEVELOP PSYCHIATRIC DISORDERS. USING A RECENTLY DEVELOPED MOUSE MODEL FOR CHRONIC SOCIAL STRESS DURING ADOLESCENCE, WE STUDIED PERSISTENT NEUROENDOCRINE AND BEHAVIORAL EFFECTS OF CHRONIC SOCIAL STRESS OBTAINED 12 MONTHS AFTER CESSATION OF THE STRESSOR. AS A REFERENCE, WE INVESTIGATED IMMEDIATE EFFECTS OF CHRONIC STRESS EXPOSURE OBTAINED AT THE END OF THE CHRONIC STRESS PERIOD. IMMEDIATELY AFTER THE 7 WEEK CHRONIC STRESS PERIOD STRESSED ANIMALS SHOW SIGNIFICANTLY INCREASED ADRENAL WEIGHTS, DECREASED THYMUS WEIGHT, INCREASED BASAL CORTICOSTERONE SECRETION AND A FLATTENED CIRCADIAN RHYTHM. FURTHERMORE, STRESSED ANIMALS DISPLAY AN INCREASED ANXIETY-LIKE BEHAVIOR IN THE ELEVATED PLUS MAZE AND THE NOVELTY-INDUCED SUPPRESSION OF FEEDING TEST. HIPPOCAMPAL MINERALOCORTICOID RECEPTOR (MR) AND THE GLUCOCORTICOID RECEPTOR (GR) MRNA LEVELS WERE SIGNIFICANTLY DECREASED. TO INVESTIGATE PERSISTENT CONSEQUENCES OF THIS EARLY STRESSFUL EXPERIENCE, THE SAME PARAMETERS WERE ASSESSED IN AGED MICE 12 MONTHS AFTER THE CESSATION OF THE STRESSOR. INTERESTINGLY, WE STILL FOUND DIFFERENCES BETWEEN FORMERLY STRESSED AND CONTROL MICE IN IMPORTANT STRESS-RELATED PARAMETERS. MR EXPRESSION LEVELS WERE SIGNIFICANTLY LOWER IN STRESSED ANIMALS, SUGGESTING LASTING, POSSIBLY EPIGENETIC ALTERATIONS IN GENE EXPRESSION REGULATION. FURTHERMORE, WE OBSERVED LONG-TERM BEHAVIORAL ALTERATIONS IN ANIMALS STRESSED DURING ADOLESCENCE. THUS, WE COULD DEMONSTRATE THAT CHRONIC STRESS EXPOSURE DURING A CRUCIAL DEVELOPMENTAL TIME PERIOD RESULTS IN LONG-TERM, PERSISTENT EFFECTS ON PHYSIOLOGICAL AND BEHAVIORAL PARAMETERS THROUGHOUT LIFE, WHICH MAY CONTRIBUTE TO AN ENHANCED VULNERABILITY TO STRESS-INDUCED DISEASES. 2008 4 5019 43 PERSISTENT INFLAMMATORY PAIN IS LINKED WITH ANXIETY-LIKE BEHAVIORS, INCREASED BLOOD CORTICOSTERONE, AND REDUCED GLOBAL DNA METHYLATION IN THE RAT AMYGDALA. CHRONIC PAIN INCREASES THE RISK OF DEVELOPING ANXIETY, WITH LIMBIC AREAS BEING LIKELY NEUROLOGICAL SUBSTRATES. DESPITE HIGH CLINICAL RELEVANCE, LITTLE IS KNOWN ABOUT THE PRECISE BEHAVIORAL, HORMONAL, AND BRAIN NEUROPLASTIC CORRELATES OF ANXIETY IN THE CONTEXT OF PERSISTENT PAIN. PREVIOUS STUDIES HAVE SHOWN THAT DECREASED NOCICEPTIVE THRESHOLDS IN CHRONIC PAIN MODELS ARE PARALLELED BY ANXIETY-LIKE BEHAVIOR IN RATS, BUT THERE ARE CONFLICTING IDEAS REGARDING ITS EFFECTS ON THE STRESS RESPONSE AND CIRCULATING CORTICOSTERONE LEVELS. EVEN LESS IS KNOWN ABOUT THE MOLECULAR MECHANISMS THROUGH WHICH THE BRAIN ENCODES PAIN-RELATED ANXIETY. THIS STUDY EXAMINES HOW PERSISTENT INFLAMMATORY PAIN IN A RAT MODEL WOULD IMPACT ANXIETY-LIKE BEHAVIORS AND CORTICOSTERONE RELEASE, AND WHETHER THESE CHANGES WOULD BE REFLECTED IN LEVELS OF GLOBAL DNA METHYLATION IN BRAIN AREAS INVOLVED IN STRESS REGULATION. COMPLETE FREUND'S ADJUVANT (CFA) OR SALINE WAS ADMINISTERED IN THE RIGHT HINDPAW OF ADULT MALE WISTAR RATS. BEHAVIORAL TESTING INCLUDED THE MEASUREMENT OF NOCICEPTIVE THRESHOLDS (DIGITAL ANESTHESIOMETER), MOTOR FUNCTION (OPEN FIELD TEST), AND ANXIETY-LIKE BEHAVIORS (ELEVATED PLUS MAZE AND THE DARK-LIGHT BOX TEST). CORTICOSTERONE WAS MEASURED VIA RADIOIMMUNOASSAY. GLOBAL DNA METHYLATION (ENZYME IMMUNOASSAY) AS WELL AS DNMT3A LEVELS (WESTERN BLOTTING) WERE QUANTIFIED IN THE AMYGDALA, PREFRONTAL CORTEX, AND VENTRAL HIPPOCAMPUS. CFA ADMINISTRATION RESULTED IN PERSISTENT REDUCTION IN NOCICEPTIVE THRESHOLD IN THE ABSENCE OF LOCOMOTOR ABNORMALITIES. INCREASED ANXIETY-LIKE BEHAVIORS WERE OBSERVED IN THE ELEVATED PLUS MAZE AND WERE ACCOMPANIED BY INCREASED BLOOD CORTICOSTERONE LEVELS 10 DAYS AFTER PAIN INDUCTION. GLOBAL DNA METHYLATION WAS DECREASED IN THE AMYGDALA, WITH NO CHANGES IN DNMT3A ABUNDANCE IN ANY OF THE REGIONS EXAMINED. PERSISTENT INFLAMMATORY PAIN PROMOTES ANXIETY -LIKE BEHAVIORS, HPA AXIS ACTIVATION, AND EPIGENETIC REGULATION THROUGH DNA METHYLATION IN THE AMYGDALA. THESE FINDINGS DESCRIBE A MOLECULAR MECHANISM THAT LINKS PAIN AND STRESS IN A WELL-CHARACTERIZED RODENT MODEL. 2022 5 586 31 BEHAVIOURAL AND EPIGENETIC EFFECTS OF PATERNAL EXPOSURE TO CANNABINOIDS DURING ADOLESCENCE ON OFFSPRING VULNERABILITY TO STRESS. CHRONIC CANNABINOID EXPOSURE DURING ADOLESCENCE IN MALE RATS INDUCES CHRONIC COGNITIVE AND EMOTIONAL IMPAIRMENTS. HOWEVER, THE IMPACT OF THIS FORM OF EXPOSURE ON OFFSPRING VULNERABILITY TO STRESS IS UNKNOWN. THE AIM OF THIS STUDY WAS TO EVALUATE THE BEHAVIOURAL AND EPIGENETIC EFFECTS OF STRESS IN THE OFFSPRING OF MALE RATS WHOSE FATHERS WERE EXPOSED TO CANNABINOIDS DURING ADOLESCENCE. MALE ADOLESCENT OFFSPRING OF WIN55,212-2 (1.2 MG/KG) TREATED RATS WERE EXPOSED DURING ONE WEEK TO VARIABLE STRESSORS AND SUBJECTED TO BEHAVIOURAL TESTS OF ANXIETY AND EPISODIC-LIKE MEMORY, FOLLOWED BY AN ASSESSMENT OF GLOBAL DNA METHYLATION AND EXPRESSION OF DNA METHYLTRANSFERASES ENZYMES DNMT1 AND DNMT3A MRNA IN THE PREFRONTAL CORTEX. STRESS EXPOSURE INDUCED A SIGNIFICANT ANXIOGENIC-LIKE EFFECT BUT DID NOT AFFECT THE EPISODIC-LIKE MEMORY IN THE OFFSPRING OF WIN55,212-2 EXPOSED FATHERS IN COMPARISON TO THE OFFSPRING OF NON-EXPOSED FATHERS. THESE BEHAVIOURAL CHANGES WERE SUBSEQUENT TO A SIGNIFICANT INCREASE IN GLOBAL DNA METHYLATION AND DNMT1 AND DNMTA3 TRANSCRIPTION IN THE PREFRONTAL CORTEX. THESE DATA SUGGEST THAT THE DELETERIOUS EFFECT OF CHRONIC EXPOSURE TO CANNABINOIDS DURING ADOLESCENCE ARE NOT LIMITED TO THE EXPOSED INDIVIDUALS BUT MAY INCREASE THE VULNERABILITY TO STRESS-INDUCED ANXIETY IN THE OFFSPRING AND ALTER THEIR EPIGENETIC PROGRAMMING. 2019 6 1808 49 EFFECTS OF ADOLESCENT SOCIAL STRESS AND ANTIDEPRESSANT TREATMENT ON COGNITIVE INFLEXIBILITY AND BDNF EPIGENETIC MODIFICATIONS IN THE MPFC OF ADULT MICE. ADOLESCENT SOCIAL STRESS (ASS) CAN INCREASE SUSCEPTIBILITY TO DEPRESSION IN ADULTHOOD. HOWEVER, THE UNDERLYING PSYCHOLOGICAL AND NEURAL MECHANISMS REMAIN UNCLEAR. CORTICALLY MEDIATED COGNITIVE DYSFUNCTIONS ARE INCREASINGLY RECOGNIZED AS AN INDEPENDENT AND IMPORTANT RISK FACTOR OF DEPRESSION. USING SOCIAL DEFEAT STRESS, A CLASSICAL ANIMAL MODEL OF DEPRESSION, OUR PREVIOUS STUDIES FOUND THAT MICE SUBJECTED TO THIS FORM OF STRESS DURING EARLY ADOLESCENCE DISPLAYED COGNITIVE INFLEXIBILITY (CI) IN ADULTHOOD. THIS CHANGE WAS ACCOMPANIED BY A DOWN-REGULATION OF BDNF GENE EXPRESSION IN THE MEDIAL PREFRONTAL CORTEX (MPFC); THIS GENE ENCODES A KEY MOLECULE INVOLVED IN DEPRESSION AND ANTIDEPRESSANT ACTION. IN THE PRESENT PAPER, WE IDENTIFIED EPIGENETIC MODIFICATION OF BDNF AS A POSSIBLE MECHANISM UNDERLYING THE BEHAVIORAL AND MOLECULAR CHANGES. ASS INDUCED A SET OF DEPRESSIVE PHENOTYPES, INCLUDING INCREASED SOCIAL AVOIDANCE AND CI, AS WELL AS REDUCED LEVELS OF TOTAL BDNF AND ISOFORM IV BUT NOT ISOFORM I OR VI TRANSCRIPTS IN THE MPFC. IN PARALLEL WITH CHANGES IN BDNF GENE EXPRESSION, PREVIOUSLY STRESSED ADULT MICE SHOWED INCREASED LEVELS OF DIMETHYLATION OF HISTONE H3 AT LYSINE K9 (H3K9ME2) IMMEDIATELY DOWNSTREAM OF THE BDNF IV PROMOTER. ON THE OTHER HAND, NO DIFFERENCES WERE FOUND IN TRIMETHYLATION OF HISTONE H3 AT LYSINE K4 (H3K4ME3) OR IN ACETYLATION OF HISTONE H3 AT LYSINE K9 (H3K9AC) OR AT K4 (H3K4AC) IN THE BDNF IV PROMOTER. LIKEWISE, NO ALTERATIONS WERE FOUND IN DNA METHYLATION OF THE BDNF IV PROMOTER. ADDITIONALLY, TREATMENT WITH THE CHRONIC ANTIDEPRESSANT TRANYLCYPROMINE REVERSED BDNF EPIGENETIC CHANGES AND RELATED GENE TRANSCRIPTION WHILE ALSO REVERSING CI, BUT NOT SOCIAL AVOIDANCE, IN PREVIOUSLY STRESSED ADULT MICE. THESE RESULTS SUGGEST THAT EPIGENETIC CHANGES TO THE BDNF GENE IN THE MPFC AFTER ADOLESCENT SOCIAL ADVERSITY MAY BE INVOLVED IN THE REGULATION OF COGNITIVE DYSFUNCTION IN DEPRESSION AND ANTIDEPRESSANT ACTION IN ADULTHOOD. 2018 7 5207 37 PRENATAL STRESS INDUCES SPATIAL MEMORY DEFICITS AND EPIGENETIC CHANGES IN THE HIPPOCAMPUS INDICATIVE OF HETEROCHROMATIN FORMATION AND REDUCED GENE EXPRESSION. STRESS DURING PREGNANCY HAS A WIDE VARIETY OF NEGATIVE EFFECTS IN BOTH HUMAN [1] AND ANIMAL OFFSPRING [2]. THESE EFFECTS ARE ESPECIALLY APPARENT IN VARIOUS FORMS OF LEARNING AND MEMORY SUCH AS OBJECT RECOGNITION [3] AND SPATIAL MEMORY [4]. THE COGNITIVE EFFECTS OF PRENATAL STRESS (PNS) MAY BE MEDIATED THROUGH EPIGENETIC CHANGES SUCH AS HISTONE ACETYLATION AND DNA METHYLATION [5]. AS SUCH, THE PRESENT STUDY INVESTIGATED THE EFFECTS OF CHRONIC UNPREDICTABLE PNS ON MEMORY AND EPIGENETIC MEASURES IN ADULT OFFSPRING. MICE THAT UNDERWENT PNS EXHIBITED IMPAIRED SPATIAL MEMORY IN THE MORRIS WATER MAZE, AS WELL AS SEX-SPECIFIC CHANGES IN LEVELS OF DNA METHYLTRANSFERASE (DNMT) 1 PROTEIN, AND ACETYLATED HISTONE H3 (ACH3) IN THE HIPPOCAMPUS, AND SERUM CORTICOSTERONE. MALE MICE EXPOSED TO PNS EXHIBITED DECREASED HIPPOCAMPAL ACH3, WHEREAS FEMALE PNS MICE DISPLAYED A FURTHER REDUCTION IN ACH3, AS WELL AS HEIGHTENED HIPPOCAMPAL DNMT1 PROTEIN LEVELS AND CORTICOSTERONE LEVELS. THESE DATA SUGGEST THAT PNS MAY EPIGENETICALLY REDUCE TRANSCRIPTION IN THE HIPPOCAMPUS, PARTICULARLY IN FEMALES IN WHOM THIS EFFECT MAY BE RELATED TO INCREASED BASELINE STRESS HORMONE LEVELS, AND WHICH MAY UNDERLIE THE SEXUAL DIMORPHISM IN RATES OF MENTAL ILLNESS IN HUMANS. 2015 8 1761 39 EARLY STRESS EVOKES AGE-DEPENDENT BIPHASIC CHANGES IN HIPPOCAMPAL NEUROGENESIS, BDNF EXPRESSION, AND COGNITION. BACKGROUND: ADULT-ONSET STRESSORS EXERT OPPOSING EFFECTS ON HIPPOCAMPAL NEUROGENESIS AND COGNITION, WITH ENHANCEMENT OBSERVED FOLLOWING MILD STRESS AND DYSFUNCTION FOLLOWING SEVERE CHRONIC STRESS. WHILE EARLY LIFE STRESS EVOKES PERSISTENT CHANGES IN ANXIETY, IT IS UNKNOWN WHETHER EARLY STRESS DIFFERENTIALLY REGULATES HIPPOCAMPAL NEUROGENESIS, TROPHIC FACTOR EXPRESSION, AND COGNITION ACROSS THE LIFE SPAN. METHODS: HIPPOCAMPAL-DEPENDENT COGNITIVE BEHAVIOR, NEUROGENESIS, AND EPIGENETIC REGULATION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) EXPRESSION WAS EXAMINED AT DISTINCT TIME POINTS ACROSS THE LIFE SPAN IN RATS SUBJECTED TO THE EARLY STRESS OF MATERNAL SEPARATION (ES) AND CONTROL GROUPS. WE ALSO EXAMINED THE INFLUENCE OF CHRONIC ANTIDEPRESSANT TREATMENT ON THE NEUROGENIC, NEUROTROPHIC, AND COGNITIVE CHANGES IN MIDDLE-AGED ES ANIMALS. RESULTS: ANIMALS SUBJECTED TO EARLY STRESS OF MATERNAL SEPARATION EXAMINED DURING POSTNATAL LIFE AND YOUNG ADULTHOOD EXHIBITED ENHANCED HIPPOCAMPAL NEUROGENESIS, DECREASED REPRESSIVE HISTONE METHYLATION AT THE BDNF IV PROMOTER ALONG WITH ENHANCED BDNF LEVELS, AND IMPROVED PERFORMANCE ON THE STRESS-ASSOCIATED MORRIS WATER MAZE. STRIKINGLY, OPPOSING CHANGES IN HIPPOCAMPAL NEUROGENESIS AND EPIGENETIC REGULATION OF BDNF IV EXPRESSION, CONCOMITANT WITH IMPAIRMENTS ON HIPPOCAMPAL-DEPENDENT COGNITIVE TASKS, WERE OBSERVED IN MIDDLE-AGED ES ANIMALS. CHRONIC ANTIDEPRESSANT TREATMENT WITH AMITRIPTYLINE ATTENUATED THE MALADAPTIVE NEUROGENIC, EPIGENETIC, TRANSCRIPTIONAL, AND COGNITIVE EFFECTS IN MIDDLE-AGED ES ANIMALS. CONCLUSIONS: OUR STUDY PROVIDES NOVEL INSIGHTS INTO THE SHORT- AND LONG-TERM CONSEQUENCES OF ES, DEMONSTRATING BOTH BIPHASIC AND UNIQUE, AGE-DEPENDENT CHANGES AT THE MOLECULAR, EPIGENETIC, NEUROGENIC, AND BEHAVIORAL LEVELS. THESE RESULTS INDICATE THAT EARLY STRESS MAY TRANSIENTLY ENDOW ANIMALS WITH A POTENTIAL ADAPTIVE ADVANTAGE IN STRESSFUL ENVIRONMENTS BUT ACROSS A LIFE SPAN IS ASSOCIATED WITH LONG-TERM DELETERIOUS EFFECTS. 2013 9 1004 46 CHRONIC TREATMENT WITH HORMONAL CONTRACEPTIVES ALTERS HIPPOCAMPAL BDNF AND HISTONE H3 POST-TRANSLATIONAL MODIFICATIONS BUT NOT LEARNING AND MEMORY IN FEMALE RATS. HORMONAL CONTRACEPTIVES PREVENT OVULATION WITH SUBSEQUENT REDUCTION IN ENDOGENOUS LEVELS OF ESTRADIOL, PROGESTERONE AND ITS NEUROACTIVE METABOLITE ALLOPREGNANOLONE. THESE NEUROSTEROIDS MODULATE SEVERAL BRAIN FUNCTIONS, INCLUDING NEURONAL PLASTICITY, COGNITION AND MEMORY. WE HYPOTHESIZED THAT HORMONAL CONTRACEPTIVES MIGHT AFFECT SYNAPTIC PLASTICITY, LEARNING AND MEMORY, AS A CONSEQUENCE OF SUPPRESSED ENDOGENOUS HORMONES LEVELS. FEMALE RATS WERE ORALLY TREATED WITH A COMBINATION OF ETHINYL ESTRADIOL (EE, 0.020 MG) AND LEVONORGESTREL (LNG, 0.060 MG) ONCE DAILY FOR FOUR WEEKS. DECREASED HIPPOCAMPAL BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) LEVELS AND ALTERED HISTONE H3 POST-TRANSLATIONAL MODIFICATIONS (PTMS) WERE OBSERVED 14 DAYS AFTER DISCONTINUATION FROM CHRONIC EE-LNG TREATMENT. THESE EFFECTS WERE NOT ACCOMPANIED BY ALTERATIONS IN LONG-TERM PLASTICITY AT GLUTAMATERGIC SYNAPSES, RECOGNITION MEMORY IN THE NOVEL OBJECT AND NOVEL PLACE LOCATION TESTS, OR SPATIAL LEARNING, MEMORY, AND BEHAVIORAL FLEXIBILITY IN THE MORRIS WATER MAZE TEST. THUS, DECREASED BDNF CONTENT DOES NOT AFFECT SYNAPTIC PLASTICITY AND COGNITIVE PERFORMANCE; RATHER IT MIGHT BE RELEVANT FOR THE OCCURRENCE OF CERTAIN PSYCHIATRIC SYMPTOMS, REPORTED BY SOME WOMEN USING HORMONAL CONTRACEPTIVES. THESE RESULTS PROVIDE THE FIRST EVIDENCE OF HIPPOCAMPAL EPIGENETIC CHANGES INDUCED BY HORMONAL CONTRACEPTIVES AND COMPLEMENT PREVIOUS STUDIES ON THE NEUROBIOLOGICAL ACTIONS OF HORMONAL CONTRACEPTIVES; THE FINDING THAT EFFECTS OF CHRONIC EE-LNG TREATMENT ON BDNF CONTENT AND HISTONE PTMS ARE OBSERVED 14 DAYS AFTER DRUG DISCONTINUATION WARRANTS FURTHER INVESTIGATION TO BETTER UNDERSTAND THE IMPLICATIONS OF SUCH LONG-TERM CONSEQUENCES FOR WOMEN'S HEALTH. 2022 10 2740 31 EXPOSURE TO EARLY LIFE STRESS RESULTS IN EPIGENETIC CHANGES IN NEUROTROPHIC FACTOR GENE EXPRESSION IN A PARKINSONIAN RAT MODEL. EARLY LIFE ADVERSITY INCREASES THE RISK OF MENTAL DISORDERS LATER IN LIFE. CHRONIC EARLY LIFE STRESS MAY ALTER NEUROTROPHIC FACTOR GENE EXPRESSION INCLUDING THOSE FOR BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) AND GLIAL CELL DERIVED NEUROTROPHIC FACTOR (GDNF) THAT ARE IMPORTANT IN NEURONAL GROWTH, SURVIVAL, AND MAINTENANCE. MATERNAL SEPARATION WAS USED IN THIS STUDY TO MODEL EARLY LIFE STRESS. FOLLOWING UNILATERAL INJECTION OF A MILD DOSE OF 6-HYDROXYDOPAMINE (6-OHDA), WE MEASURED CORTICOSTERONE (CORT) IN THE BLOOD AND STRIATUM OF STRESSED AND NONSTRESSED RATS; WE ALSO MEASURED DNA METHYLATION AND BDNF AND GDNF GENE EXPRESSION IN THE STRIATUM USING REAL TIME PCR. IN THE PRESENCE OF STRESS, WE FOUND THAT THERE WAS INCREASED CORTICOSTERONE CONCENTRATION IN BOTH BLOOD AND STRIATAL TISSUE. FURTHER TO THIS, WE FOUND HIGHER DNA METHYLATION AND DECREASED NEUROTROPHIC FACTOR GENE EXPRESSION. 6-OHDA LESION INCREASED NEUROTROPHIC FACTOR GENE EXPRESSION IN BOTH STRESSED AND NONSTRESSED RATS BUT THIS INCREASE WAS HIGHER IN THE NONSTRESSED RATS. OUR RESULTS SUGGEST THAT EXPOSURE TO EARLY POSTNATAL STRESS INCREASES CORTICOSTERONE CONCENTRATION WHICH LEADS TO INCREASED DNA METHYLATION. THIS EFFECT RESULTS IN DECREASED BDNF AND GDNF GENE EXPRESSION IN THE STRIATUM LEADING TO DECREASED PROTECTION AGAINST SUBSEQUENT INSULTS LATER IN LIFE. 2016 11 5206 44 PRENATAL STRESS INDUCES LONG-TERM BEHAVIORAL SEX-DEPENDENT CHANGES IN RATS OFFSPRING: THE ROLE OF THE HPA AXIS AND EPIGENETICS. PRECLINICAL GENETIC STUDIES HAVE RELATED STRESS EARLY EXPOSURES WITH CHANGES IN GENE REGULATORY MECHANISMS, INCLUDING EPIGENETIC ALTERATIONS, SUCH AS MODIFICATIONS OF DNA METHYLATION, HISTONE DEACETYLATION, AND HISTONES ACETYLATION. THIS STUDY EVALUATES THE EFFECTS OF PRENATAL STRESS ON THE BEHAVIOR, HYPOTHALAMUS-PITUITARY-ADRENAL (HPA)-AXIS, AND EPIGENETIC PARAMETERS IN STRESSED DAMS AND THEIR OFFSPRING. THE RATS WERE SUBJECTED TO A PROTOCOL OF CHRONIC UNPREDICTABLE MILD STRESS ON THE FOURTEENTH DAY OF PREGNANCY UNTIL THE BIRTH OF OFFSPRING. AFTER BIRTH, MATERNAL CARE WAS EVALUATED FOR SIX DAYS. FOLLOWING WEANING, THE LOCOMOTOR AND DEPRESSIVE-LIKE BEHAVIORS OF THE DAMS AND THEIR OFFSPRING (60 DAYS OLD) WERE ASSESSED. THE HPA AXIS PARAMETERS WERE EVALUATED IN SERUM FROM DAMS AND OFFSPRING, AND EPIGENETIC PARAMETERS (HISTONE ACETYLTRANSFERASE (HAT), HISTONE DEACETYLASE (HDAC), DNA METHYLTRANSFERASE (DNMT) ACTIVITIES, AND THE LEVELS OF HISTONE H3 ACETYLATED AT LYSINE RESIDUE 9 (H3K9AC) AND HISTONE 3 ACETYLATED AT LYSINE RESIDUE 14 (H3K14AC)) WERE ASSESSED IN DAMS' AND OFFSPRING' BRAINS. PRENATAL STRESS DID NOT SIGNIFICANTLY INFLUENCE MATERNAL CARE; HOWEVER, IT INDUCED MANIC BEHAVIOR IN FEMALE OFFSPRING. THESE BEHAVIORAL ALTERATIONS IN THE OFFSPRING WERE ACCOMPANIED BY HYPERACTIVITY OF THE HPA-AXIS, EPIGENETIC ADAPTATIONS IN THE ACTIVITY OF HDAC AND DNMT, AND ACETYLATION IN THE HISTONES H3K9 AND H3K14. IN ADDITION, THE PRENATAL STRESSED FEMALE OFFSPRING SHOWED INCREASED LEVELS OF ACTH COMPARED TO THEIR MALE COUNTERPART. OUR FINDINGS REINFORCE THE IMPACT OF PRENATAL STRESS ON BEHAVIOR, STRESS RESPONSE, AND EPIGENETIC PROFILE OF OFFSPRING. 2023 12 3177 41 H3K9ME2 REGULATION OF BDNF EXPRESSION IN THE HIPPOCAMPUS AND MEDIAL PREFRONTAL CORTEX IS INVOLVED IN THE DEPRESSIVE-LIKE PHENOTYPE INDUCED BY MATERNAL SEPARATION IN MALE RATS. BACKGROUND: EARLY LIFE STRESS (ELS) INDUCES A DEPRESSIVE-LIKE PHENOTYPE AND INCREASES THE RISK OF DEPRESSION. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) HAS BEEN CONFIRMED TO BE INVOLVED IN THE PATHOPHYSIOLOGY OF DEPRESSION. HOWEVER, THE MECHANISM BY WHICH ELS ALTERS THE EPIGENETIC REGULATION OF BDNF AND CHANGES SUSCEPTIBILITY TO DEPRESSION HAS NOT BEEN FULLY CLARIFIED. METHODS: THE PRESENT STUDY USED MATERNAL SEPARATION (MS) AND CHRONIC UNPREDICTED MILD STRESS (CUMS) TO ESTABLISH AN MS ANIMAL MODEL AND A DEPRESSIVE ANIMAL MODEL. WE ASSESSED DEPRESSIVE-LIKE BEHAVIOURS, INCLUDING ANHEDONIA, LOCOMOTOR ACTIVITY, ANXIETY-LIKE BEHAVIOUR, AND SPATIAL MEMORY, USING THE SUCROSE PREFERENCE TEST, THE OPEN FIELD TEST, THE ELEVATED PLUS MAZE TEST, AND THE MORRIS WATER MAZE TEST. WE ALSO INVESTIGATED BDNF AND H3K9ME2 EXPRESSION IN THE HIPPOCAMPUS AND MEDIAL PREFRONTAL CORTEX (MPFC) BY IMMUNOHISTOCHEMISTRY, WESTERN BLOTTING, AND QPCR ANALYSIS. ADDITIONALLY, WE USED UNC0642, A SMALL MOLECULE INHIBITOR OF HISTONE METHYLTRANSFERASE (G9A), AS AN INTERVENTION. RESULTS: THE RESULTS SHOWED THAT CUMS INDUCED DEPRESSIVE-LIKE BEHAVIOURS IN RATS AND RESULTED IN INCREASED H3K9ME2 EXPRESSION AND DECREASED BDNF EXPRESSION IN THE HIPPOCAMPUS AND MPFC. MORE IMPORTANTLY, ADULT MS RATS EXPERIENCING CUMS HAD MORE SEVERE DEPRESSIVE BEHAVIOURS, HAD HIGHER EXPRESSION OF H3K9ME2 IN THE HIPPOCAMPUS AND MPFC, AND HAD LOWER EXPRESSION OF BDNF IN THE HIPPOCAMPUS AND MPFC. IN ADDITION, ADMINISTRATION OF THE G9A INHIBITOR REVERSED MOST OF THE CHANGES. CONCLUSIONS: OUR STUDY SUGGESTS THAT ELS CHANGED BDNF AND H3K9ME2 EXPRESSION IN THE RAT BRAIN, RESULTING IN A DEPRESSIVE-LIKE PHENOTYPE. 2021 13 1753 35 EARLY LIFE STRESS TRIGGERS SUSTAINED CHANGES IN HISTONE DEACETYLASE EXPRESSION AND HISTONE H4 MODIFICATIONS THAT ALTER RESPONSIVENESS TO ADOLESCENT ANTIDEPRESSANT TREATMENT. EARLY LIFE STRESS CAN ELICIT LONG-LASTING CHANGES IN GENE EXPRESSION AND BEHAVIOR. RECENT STUDIES ON RODENTS SUGGEST THAT THESE LASTING EFFECTS DEPEND ON THE GENETIC BACKGROUND. WHETHER EPIGENETIC FACTORS ALSO PLAY A ROLE REMAINS TO BE INVESTIGATED. HERE WE EXPOSED THE STRESS-SUSCEPTIBLE MOUSE STRAIN BALB/C AND THE MORE RESILIENT STRAIN C57BL/6 TO A POWERFUL EARLY LIFE STRESS PARADIGM, INFANT MATERNAL SEPARATION. IN BALB/C MICE, INFANT MATERNAL SEPARATION LED TO DECREASED EXPRESSION OF MRNA ENCODING THE HISTONE DEACETYLASES (HDACS) 1, 3, 7, 8, AND 10 IN THE FOREBRAIN NEOCORTEX IN ADULTHOOD, AN EFFECT ACCOMPANIED BY INCREASED EXPRESSION OF ACETYLATED HISTONE H4 PROTEINS, ESPECIALLY ACETYLATED H4K12 PROTEIN. THESE CHANGES IN HDAC EXPRESSION AND HISTONE MODIFICATIONS WERE NOT DETECTED IN C57BL/6 MICE EXPOSED TO EARLY LIFE STRESS. MOREOVER, A REVERSAL OF THE H4K12 HYPERACETYLATION DETECTED IN INFANT MATERNALLY SEPARATED BALB/C MICE (ACHIEVED WITH CHRONIC ADOLESCENT TREATMENT WITH A LOW DOSE OF THEOPHYLLINE THAT ONLY ACTIVATES HDACS) WORSENED THE ABNORMAL EMOTIONAL PHENOTYPE RESULTING FROM THIS EARLY LIFE STRESS EXPOSURE. IN CONTRAST, FLUOXETINE, A DRUG WITH POTENT ANTIDEPRESSANT EFFICACY IN INFANT MATERNALLY SEPARATED BALB/C MICE, POTENTIATED ALL HISTONE MODIFICATIONS TRIGGERED BY EARLY LIFE STRESS. MOREOVER, IN NON-STRESSED BALB/C MICE, CO-ADMINISTRATION OF AN HDAC INHIBITOR AND FLUOXETINE, BUT NOT FLUOXETINE ALONE, ELICITED ANTIDEPRESSANT EFFECTS AND ALSO TRIGGERED CHANGES IN HISTONE H4 EXPRESSION THAT WERE SIMILAR TO THOSE PROVOKED BY FLUOXETINE TREATMENT OF MICE EXPOSED TO EARLY LIFE STRESS. THESE RESULTS SUGGEST THAT BALB/C MICE DEVELOP EPIGENETIC MODIFICATIONS AFTER EARLY LIFE STRESS EXPOSURE THAT, IN TERMS OF THE EMOTIVE PHENOTYPE, ARE OF ADAPTIVE NATURE, AND THAT ENHANCE THE EFFICACY OF ANTIDEPRESSANT DRUGS. 2012 14 3462 32 HYPOTHALAMIC NR3C1 DNA METHYLATION IN RATS EXPOSED TO PRENATAL STRESS. BACKGROUND: HUMAN AND ANIMAL STUDIES HAVE INDICATED THAT MATERNAL PRENATAL STRESS (PS) HAS MOLECULAR AND BEHAVIORAL EFFECTS DURING PREGNANCY AND EARLY LIFE. THE PRESENT STUDY AIMED TO EVALUATE THE EPIGENETIC CHANGES OF THE NR3C1 GENE INVOLVED IN THE HPA AXIS IN THE HYPOTHALAMIC TISSUES OF RATS EXPOSED TO PS INDUCED BY CHRONIC UNPREDICTABLE MILD STRESS (CUMS). BEHAVIORAL AND MOLECULAR EFFECTS OF THESE CHANGES ON THE NEXT GENERATION WERE ALSO ASSESSED. METHODS AND RESULTS: CUMS PROTOCOL WAS USED TO GENERATE STRESS IN PREGNANT WISTAR RATS. TO DETERMINE THE EFFECTS OF STRESS ON ANHEDONIA AND MOVEMENT, SUCROSE PREFERENCE TEST, FORCED SWIMMING TEST, AND OPEN FIELD TEST WERE PERFORMED. FOLLOWING THESE BEHAVIORAL EXPERIMENTS, BISULFITE SEQUENCING PCR FOR DNA METHYLATION LEVELS OF THE NR3C1 GENE, RT-QPCR FOR MRNA LEVELS, AND WESTERN BLOT TECHNIQUES FOR PROTEIN ANALYSIS WERE USED IN THE HYPOTHALAMIC TISSUE OF SACRIFICED RATS. DEPRESSION-LIKE BEHAVIORS WERE EVIDENT IN THE BEHAVIORAL TESTS OF STRESS-EXPOSED MOTHERS AND PUPS. IN PS-EXPOSED PUPS, HYPOTHALAMIC NR3C1 PROMOTER METHYLATION WAS HIGHER, AND NR3C1 MRNA LEVELS AND NR3C1 PROTEIN LEVELS WERE LOWER COMPARED WITH CONTROLS, REGARDLESS OF SEX. CONCLUSION: OUR RESULTS CONFIRM THE RELATIONSHIP BETWEEN PS AND EPIGENETIC CHANGES OF HPA AXIS-RELATED GENES AND SHOW THAT NR3C1 GENE METHYLATION STATUS IN PUPS IS SENSITIVE TO PS DURING PREGNANCY. ENVIRONMENTAL MATERNAL STRESS MAY HAVE TRANSGENERATIONAL EFFECTS THAT ARE POTENTIALLY ASSOCIATED WITH ADVERSE OUTCOMES IN THE PUPS. 2022 15 4949 32 PATERNAL TRANSMISSION OF STRESS-INDUCED PATHOLOGIES. BACKGROUND: THERE HAS BEEN RECENT INTEREST IN THE POSSIBILITY THAT EPIGENETIC MECHANISMS MIGHT CONTRIBUTE TO THE TRANSGENERATIONAL TRANSMISSION OF STRESS-INDUCED VULNERABILITY. HERE, WE FOCUSED ON POSSIBLE PATERNAL TRANSMISSION WITH THE SOCIAL DEFEAT STRESS PARADIGM. METHODS: ADULT MALE MICE EXPOSED TO CHRONIC SOCIAL DEFEAT STRESS OR CONTROL NONDEFEATED MICE WERE BRED WITH NORMAL FEMALE MICE, AND THEIR OFFSPRING WERE ASSESSED BEHAVIORALLY FOR DEPRESSIVE- AND ANXIETY-LIKE MEASURES. PLASMA LEVELS OF CORTICOSTERONE AND VASCULAR ENDOTHELIAL GROWTH FACTOR WERE ALSO ASSAYED. TO DIRECTLY ASSESS THE ROLE OF EPIGENETIC MECHANISMS, WE USED IN VITRO FERTILIZATION (IVF); BEHAVIORAL ASSESSMENTS WERE CONDUCTED ON OFFSPRING OF MICE FROM IVF-CONTROL AND IVF-DEFEATED FATHERS. RESULTS: WE SHOW THAT BOTH MALE AND FEMALE OFFSPRING FROM DEFEATED FATHERS EXHIBIT INCREASED MEASURES OF SEVERAL DEPRESSION- AND ANXIETY-LIKE BEHAVIORS. THE MALE OFFSPRING OF DEFEATED FATHERS ALSO DISPLAY INCREASED BASELINE PLASMA LEVELS OF CORTICOSTERONE AND DECREASED LEVELS OF VASCULAR ENDOTHELIAL GROWTH FACTOR. HOWEVER, MOST OF THESE BEHAVIORAL CHANGES WERE NOT OBSERVED WHEN OFFSPRING WERE GENERATED THROUGH IVF. CONCLUSIONS: THESE RESULTS SUGGEST THAT, ALTHOUGH BEHAVIORAL ADAPTATIONS THAT OCCUR AFTER CHRONIC SOCIAL DEFEAT STRESS CAN BE TRANSMITTED FROM THE FATHER TO HIS MALE AND FEMALE F1 PROGENY, ONLY VERY SUBTLE CHANGES MIGHT BE TRANSMITTED EPIGENETICALLY UNDER THE CONDITIONS TESTED. 2011 16 5199 41 PRENATAL MATERNAL STRESS IS ASSOCIATED WITH INCREASED SENSITIVITY TO NEUROPATHIC PAIN AND SEX-SPECIFIC CHANGES IN SUPRASPINAL MRNA EXPRESSION OF EPIGENETIC- AND STRESS-RELATED GENES IN ADULTHOOD. EXPOSURE TO PRENATAL MATERNAL STRESS IMPACTS ADULT BEHAVIORAL OUTCOMES AND HAS BEEN SUGGESTED AS A RISK FACTOR FOR CHRONIC PAIN. HOWEVER, THE NEUROBIOLOGICAL MECHANISMS IMPLICATED ARE NOT WELL-CHARACTERIZED. IN THIS STUDY, WE ANALYZED THE EFFECT OF A PRENATAL MATERNAL STRESS ON THE DEVELOPMENT OF NEUROPATHIC PAIN-RELATED BEHAVIOURS AND GENE EXPRESSION IN THE FRONTAL CORTEX AND HIPPOCAMPUS IN ADULT OFFSPRING FOLLOWING CHRONIC CONSTRICTION INJURY OF THE SCIATIC NERVE IN MALE AND FEMALE CD1 MICE. NERVE INJURY-INDUCED MECHANICAL HYPERSENSITIVITY WAS AMPLIFIED IN BOTH MALE AND FEMALE PRENATALLY-STRESSED OFFSPRING, SUGGESTING THAT PRENATAL STRESS EXACERBATES PAIN AFTER INJURY. ANALYSIS OF MRNA EXPRESSION OF GENES RELATED TO EPIGENETIC REGULATION AND STRESS RESPONSES IN THE FRONTAL CORTEX AND HIPPOCAMPUS, BRAIN STRUCTURES IMPLICATED IN CHRONIC PAIN, SHOWED DISTINCT SEX AND REGION-SPECIFIC PATTERNS OF DYSREGULATION. IN GENERAL, MRNA EXPRESSION WAS MOST FREQUENTLY ALTERED IN THE MALE HIPPOCAMPUS AND EFFECTS OF PRENATAL STRESS WERE MORE PREVALENT THAN EFFECTS OF NERVE INJURY IN BOTH SUPRASPINAL AREAS. THESE FINDINGS DEMONSTRATE THE IMPACT OF PRENATAL STRESS ON BEHAVIORAL SENSITIVITY TO A PAINFUL INJURY. CHANGES IN THE EXPRESSION OF EPIGENETIC- AND STRESS-RELATED GENES SUGGEST A POSSIBLE MECHANISM BY WHICH THE EARLY LIFE STRESS BECOMES EMBEDDED IN THE CENTRAL NERVOUS SYSTEM. INCREASED UNDERSTANDING OF THE INTERACTIONS AMONG EARLY-LIFE STRESS, SEX, AND PAIN MAY LEAD TO THE IDENTIFICATION OF NOVEL THERAPEUTIC TARGETS AND EPIGENETIC DRUGS FOR THE TREATMENT OF CHRONIC PAIN DISORDERS. 2020 17 5874 32 SWIMMING EXERCISE REVERSES CUMS-INDUCED CHANGES IN DEPRESSION-LIKE BEHAVIORS AND HIPPOCAMPAL PLASTICITY-RELATED PROTEINS. BACKGROUND: STRESS-INDUCED FAILED RESILIENCE OF BRAIN PLASTICITY CAN CONTRIBUTE TO THE ONSET AND RECURRENCE OF DEPRESSION. CHRONIC STRESS HAS BEEN REPORTED TO OPEN WINDOWS OF EPIGENETIC PLASTICITY IN HIPPOCAMPUS. HOWEVER, HOW HIPPOCAMPAL PLASTICITY UNDERLIES DEPRESSION-LIKE BEHAVIORS AND HOW IT ADAPTS IN RESPONSE TO STRESS HAS NOT BEEN ADDRESSED. THE PRESENT STUDY AIMED TO INVESTIGATE THE SIGNALING MECHANISMS OF CUMS AFFECTING HIPPOCAMPAL PLASTICITY-RELATED PROTEINS EXPRESSION AND THE REGULATION OF SWIMMING EXERCISE IN MICE. METHODS: MALE C57BL/6 MICE WERE SUBJECTED TO CHRONIC UNPREDICTABLE MILD STRESS (CUMS) FOR 7 WEEKS. FROM THE 4TH WEEK, CUMS MICE WERE TRAINED IN A MODERATE SWIMMING PROGRAM FOR A TOTAL OF 4 WEEKS. A VIDEOCOMPUTERIZED TRACKING SYSTEM WAS USED TO RECORD BEHAVIORS OF ANIMALS FOR A 5-MIN SESSION. REAL-TIME PCR AND WESTERN BLOTTING WERE USED TO EXAMINE GENE EXPRESSION IN MOUSE HIPPOCAMPUS. RESULTS: OUR RESULTS DEMONSTRATED THAT CUMS INDUCED DEPRESSION-LIKE BEHAVIORS, WHICH WERE REVERSED BY SWIMMING EXERCISE. MOREOVER, THE BEHAVIORAL CHANGES INDUCED BY CUMS AND EXERCISE WERE CORRELATED WITH HIPPOCAMPAL PLASTICITY-RELATED PROTEINS EXPRESSION OF GROWTH-ASSOCIATED PROTEIN-43 (GAP-43) AND SYNAPTOPHYSIN (SYN). THE MOLECULAR MECHANISMS REGULATING THIS PLASTICITY MAY INCLUDE SIRT1/MIRCORNA, CREB/BDNF, AND AKT/GSK-3BETA SIGNALING PATHWAYS. LIMITATIONS: WE DID NOT ESTABLISH A CORRELATION BETWEEN DEPRESSION-LIKE BEHAVIORS INDUCED BY CHRONIC STRESS AND EPIGENETIC CHANGES OF HIPPOCAMPAL PLASTICITY, EITHER A CAUSAL MOLECULAR SIGNALING UNDERLING THIS PLASTICITY. CONCLUSIONS: OUR FINDINGS HAVE IDENTIFIED SWIMMING EXERCISE EFFECTS ON CUMS-INDUCED CHANGES IN DEPRESSION-LIKE BEHAVIORS AND HIPPOCAMPAL PLASTICITY-RELATED PROTEINS, WHICH PROVIDE A FRAMEWORK FOR DEVELOPING NEW STRATEGIES TO TREAT STRESS-INDUCED DEPRESSION. 2018 18 6559 31 TRANSGENERATIONAL INFLUENCE OF PARENTAL MORPHINE EXPOSURE ON PAIN PERCEPTION, ANXIETY-LIKE BEHAVIOR AND PASSIVE AVOIDANCE MEMORY AMONG MALE AND FEMALE OFFSPRING OF WISTAR RATS. ACCUMULATING EVIDENCE SUGGESTS THAT EPIGENETIC MECHANISMS PLAY AN IMPORTANT ROLE IN THE FORMATION AND MAINTENANCE OF MEMORY WITHIN THE BRAIN. MOREOVER, THE EFFECT OF PARENTAL DRUG-EXPOSURE BEFORE GESTATION ON BEHAVIORAL STATE OF OFFSPRING HAS BEEN LITTLE STUDIED. THE MAIN OBJECTIVE OF THE CURRENT STUDY IS TO EVALUATE THE EFFECT OF PARENTAL MORPHINE EXPOSURE ON AVOIDANCE MEMORY, MORPHINE PREFERENCE AND ANXIETY-LIKE BEHAVIOR OF OFFSPRING. THE TOTAL OF 32 MALES AND 32 FEMALES WERE USED FOR MATING. THE ANIMALS WERE TREATED WITH MORPHINE. THE OFFSPRING ACCORDING TO THEIR PARENTAL MORPHINE TREATMENT WAS DIVIDED INTO FOUR GROUPS (N=16) INCLUDING PATERNALLY TREATED, MATERNALLY TREATED, BOTH OF PARENTS TREATED AND NAIVE ANIMALS. THE PAIN PERCEPTION, ANXIETY-LIKE BEHAVIOR, AND AVOIDANCE MEMORY WERE EVALUATED IN THE OFFSPRING. IN THE CURRENT STUDY, THE TOTAL OF 256 OFFSPRING WAS USED FOR THE EXPERIMENTS (4 TASKS X 4 GROUPS OF OFFSPRING X 8 FEMALE OFFSPRING X 8 MALE OFFSPRING). THE FINDING REVEALED THAT THE AVOIDANCE MEMORY AND VISCERAL PAIN WERE REDUCED SIGNIFICANTLY IN MALE AND FEMALE OFFSPRING WITH AT LEAST ONE MORPHINE-TREATED PARENT. MOREOVER, ANXIETY-LIKE BEHAVIOR WAS REDUCED SIGNIFICANTLY IN THE MALE OFFSPRING WITH AT LEAST ONE MORPHINE-TREATED PARENT. WHILE ANXIETY-LIKE BEHAVIOR WAS INCREASED SIGNIFICANTLY IN FEMALE OFFSPRING THAT WERE TREATED BY MORPHINE EITHER MATERNALLY OR BOTH OF PARENTS. THE DATA REVEALED THAT THE ENDOGENOUS OPIOID SYSTEM MAY BE ALTERED IN THE OFFSPRING OF MORPHINE-TREATED PARENT(S), AND EPIGENETIC ROLE COULD BE IMPORTANT. HOWEVER, ANALYSIS OF VARIANCE SIGNIFIED THE IMPORTANT ROLE OF MATERNAL INHERITANCE. 2019 19 2472 31 EPIGENETIC TRANSMISSION OF THE IMPACT OF EARLY STRESS ACROSS GENERATIONS. BACKGROUND: TRAUMATIC EXPERIENCES IN EARLY LIFE ARE RISK FACTORS FOR THE DEVELOPMENT OF BEHAVIORAL AND EMOTIONAL DISORDERS. SUCH DISORDERS CAN PERSIST THROUGH ADULTHOOD AND HAVE OFTEN BEEN REPORTED TO BE TRANSMITTED ACROSS GENERATIONS. METHODS: TO INVESTIGATE THE TRANSGENERATIONAL EFFECT OF EARLY STRESS, MICE WERE EXPOSED TO CHRONIC AND UNPREDICTABLE MATERNAL SEPARATION FROM POSTNATAL DAY 1 TO 14. RESULTS: WE SHOW THAT CHRONIC AND UNPREDICTABLE MATERNAL SEPARATION INDUCES DEPRESSIVE-LIKE BEHAVIORS AND ALTERS THE BEHAVIORAL RESPONSE TO AVERSIVE ENVIRONMENTS IN THE SEPARATED ANIMALS WHEN ADULT. MOST OF THE BEHAVIORAL ALTERATIONS ARE FURTHER EXPRESSED BY THE OFFSPRING OF MALES SUBJECTED TO MATERNAL SEPARATION, DESPITE THE FACT THAT THESE MALES ARE REARED NORMALLY. CHRONIC AND UNPREDICTABLE MATERNAL SEPARATION ALSO ALTERS THE PROFILE OF DNA METHYLATION IN THE PROMOTER OF SEVERAL CANDIDATE GENES IN THE GERMLINE OF THE SEPARATED MALES. COMPARABLE CHANGES IN DNA METHYLATION ARE ALSO PRESENT IN THE BRAIN OF THE OFFSPRING AND ARE ASSOCIATED WITH ALTERED GENE EXPRESSION. CONCLUSIONS: THESE FINDINGS HIGHLIGHT THE NEGATIVE IMPACT OF EARLY STRESS ON BEHAVIORAL RESPONSES ACROSS GENERATIONS AND ON THE REGULATION OF DNA METHYLATION IN THE GERMLINE. 2010 20 1803 19 EFFECT OF PROLONGED EMOTIONAL AND PAIN STRESS ON THE CONTENT OF METHYLCYTOSINE-BINDING PROTEIN MECP2 IN NUCLEI OF HIPPOCAMPAL NEURONS IN RATS WITH DIFFERENT EXCITABILITY OF THE NERVOUS SYSTEM. IN RATS WITH LOW EXCITABILITY THRESHOLD OF THE NERVOUS SYSTEM DEMONSTRATING SIGNIFICANT AND PERSISTENT BEHAVIORAL DISORDERS UNDER STRESS CONDITIONS, THE CONTENT OF METHYLCYTOSINE-BINDING PROTEIN MECP2 IN NEURONAL NUCLEI OF HIPPOCAMPAL FIELD CA3 DECREASED OVER 2 WEEKS AFTER LONG-TERM EMOTIONAL AND PAIN STRESS. IT WAS HYPOTHESIZED THAT PROTEIN MECP2 TRIGGERS EPIGENETIC CHANGES IN DNA THAT UNDERLIE "STRESS MEMORY". 2006