1 2144 89 EPIGENETIC LANDSCAPE OF STRESS SURFEIT DISORDERS: KEY ROLE FOR DNA METHYLATION DYNAMICS. CHRONIC EXPOSURE TO STRESS THROUGHOUT LIFESPAN ALTERS BRAIN STRUCTURE AND FUNCTION, INDUCING A MALADAPTIVE RESPONSE TO ENVIRONMENTAL STIMULI, THAT CAN CONTRIBUTE TO THE DEVELOPMENT OF A PATHOLOGICAL PHENOTYPE. STUDIES HAVE SHOWN THAT HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS DYSFUNCTION IS ASSOCIATED WITH VARIOUS NEUROPSYCHIATRIC DISORDERS, INCLUDING MAJOR DEPRESSIVE, ALCOHOL USE AND POST-TRAUMATIC STRESS DISORDERS. DOWNSTREAM ACTORS OF THE HPA AXIS, GLUCOCORTICOIDS ARE CRITICAL MEDIATORS OF THE STRESS RESPONSE AND EXERT THEIR FUNCTION THROUGH SPECIFIC RECEPTORS, I.E., THE GLUCOCORTICOID RECEPTOR (GR), HIGHLY EXPRESSED IN STRESS/REWARD-INTEGRATIVE PATHWAYS. GRS ARE LIGAND-ACTIVATED TRANSCRIPTION FACTORS THAT RECRUIT EPIGENETIC ACTORS TO REGULATE GENE EXPRESSION VIA DNA METHYLATION, ALTERING CHROMATIN STRUCTURE AND THUS SHAPING THE RESPONSE TO STRESS. THE DYNAMIC INTERPLAY BETWEEN STRESS RESPONSE AND EPIGENETIC MODIFIERS SUGGEST DNA METHYLATION PLAYS A KEY ROLE IN THE DEVELOPMENT OF STRESS SURFEIT DISORDERS. 2021 2 3405 34 HOW STRESS GETS UNDER THE SKIN: EARLY LIFE ADVERSITY AND GLUCOCORTICOID RECEPTOR EPIGENETIC REGULATION. EARLY LIFE ADVERSITY IS ASSOCIATED WITH BOTH PERSISTENT DISRUPTIONS IN THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS AND PSYCHIATRIC SYMPTOMS. GLUCOCORTICOID RECEPTORS (GRS), WHICH ARE ENCODED BY THE NR3C1 GENE, BIND TO CORTISOL AND OTHER GLUCOCORTICOIDS TO CREATE A NEGATIVE FEEDBACK LOOP WITHIN THE HPA AXIS TO REGULATE THE BODY'S NEUROENDOCRINE RESPONSE TO STRESS. EXCESS METHYLATION OF A PROMOTER SEQUENCE WITHIN NR3C1 THAT ATTENUATES GR EXPRESSION, HOWEVER, HAS BEEN ASSOCIATED WITH BOTH EARLY LIFE ADVERSITY AND PSYCHOPATHOLOGY. AS CRITICAL REGULATORS WITHIN THE HPA AXIS, GRS AND THEIR EPIGENETIC REGULATION MAY MEDIATE THE LINK BETWEEN EARLY LIFE ADVERSITY AND THE ONSET OF PSYCHOPATHOLOGY. THE PRESENT REVIEW DISCUSSES THIS WORK AS ONE MECHANISM BY WHICH STRESS MAY GET UNDER THE SKIN TO DISRUPT HPA FUNCTIONING AT AN EPIGENETIC LEVEL AND CREATE LONG-LASTING VULNERABILITIES IN THE STRESS REGULATORY SYSTEM THAT SUBSEQUENTLY PREDISPOSE INDIVIDUALS TO PSYCHOPATHOLOGY. SPANNING PRENATAL INFLUENCES TO CRITICAL PERIODS OF EARLY LIFE AND ADOLESCENCE, WE DETAIL THE IMPACT THAT EARLY ADVERSITY HAS ON GR EXPRESSION, PHYSIOLOGICAL RESPONSES TO STRESS, AND THEIR IMPLICATIONS FOR LONG-TERM STRESS MANAGEMENT. WE NEXT PROPOSE A DUAL TRANSMISSION HYPOTHESIS REGARDING BOTH GENOMIC AND NON-GENOMIC MECHANISMS BY WHICH CHRONIC AND ACUTE STRESS PROPAGATE THROUGH NUMEROUS GENERATIONS. LASTLY, WE OUTLINE SEVERAL DIRECTIONS FOR FUTURE RESEARCH, INCLUDING POTENTIAL REVERSIBILITY OF METHYLATION PATTERNS AND ITS FUNCTIONAL IMPLICATIONS, VARIATION IN BEHAVIOR DETERMINED SOLELY BY NR3C1, AND CONSENSUS ON WHICH SPECIFIC PROMOTER REGIONS SHOULD BE STUDIED. 2018 3 2243 25 EPIGENETIC MODULATION OF CHRONIC ANXIETY AND PAIN BY HISTONE DEACETYLATION. PROLONGED EXPOSURE OF THE CENTRAL AMYGDALA (CEA) TO ELEVATED CORTICOSTEROIDS (CORT) FACILITATES LONG-TERM ANXIETY AND PAIN THROUGH ACTIVATION OF GLUCOCORTICOID RECEPTORS (GRS) AND CORTICOTROPIN-RELEASING FACTOR (CRF). HOWEVER, THE MECHANISMS MAINTAINING THESE RESPONSES ARE UNKNOWN. SINCE CHRONIC PHENOTYPES CAN BE SUSTAINED BY EPIGENETIC MECHANISMS, INCLUDING HISTONE MODIFICATIONS SUCH AS DEACETYLATION, WE TESTED THE HYPOTHESIS THAT HISTONE DEACETYLATION CONTRIBUTES TO THE MAINTENANCE OF CHRONIC ANXIETY AND PAIN INDUCED BY PROLONGED EXPOSURE OF THE CEA TO CORT. WE FOUND THAT BILATERAL INFUSIONS OF A HISTONE DEACETYLASE INHIBITOR INTO THE CEA ATTENUATED ANXIETY-LIKE BEHAVIOR AS WELL AS SOMATIC AND VISCERAL HYPERSENSITIVITY RESULTING FROM ELEVATED CORT EXPOSURE. MOREOVER, WE DELINEATED A NOVEL PATHWAY THROUGH WHICH HISTONE DEACETYLATION COULD CONTRIBUTE TO CORT REGULATION OF GR AND SUBSEQUENT CRF EXPRESSION IN THE CEA. SPECIFICALLY, DEACETYLATION OF HISTONE 3 AT LYSINE 9 (H3K9), THROUGH THE COORDINATED ACTION OF THE NAD+-DEPENDENT PROTEIN DEACETYLASE SIRTUIN-6 (SIRT6) AND NUCLEAR FACTOR KAPPA B (NFKAPPAB), SEQUESTERS GR EXPRESSION LEADING TO DISINHIBITION OF CRF. OUR RESULTS INDICATE THAT EPIGENETIC PROGRAMMING IN THE AMYGDALA, SPECIFICALLY HISTONE MODIFICATIONS, IS IMPORTANT IN THE MAINTENANCE OF CHRONIC ANXIETY AND PAIN. 2015 4 4222 31 METHYLATION AT THE CPG ISLAND SHORE REGION UPREGULATES NR3C1 PROMOTER ACTIVITY AFTER EARLY-LIFE STRESS. EARLY-LIFE STRESS (ELS) INDUCES LONG-LASTING CHANGES IN GENE EXPRESSION CONFERRING AN INCREASED RISK FOR THE DEVELOPMENT OF STRESS-RELATED MENTAL DISORDERS. GLUCOCORTICOID RECEPTORS (GR) MEDIATE THE NEGATIVE FEEDBACK ACTIONS OF GLUCOCORTICOIDS (GC) IN THE PARAVENTRICULAR NUCLEUS (PVN) OF THE HYPOTHALAMUS AND ANTERIOR PITUITARY AND THEREFORE PLAY A KEY ROLE IN THE REGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS AND THE ENDOCRINE RESPONSE TO STRESS. WE HERE SHOW THAT ELS PROGRAMS THE EXPRESSION OF THE GR GENE (NR3C1) BY SITE-SPECIFIC HYPERMETHYLATION AT THE CPG ISLAND (CGI) SHORE IN HYPOTHALAMIC NEURONS THAT PRODUCE CORTICOTROPIN-RELEASING HORMONE (CRH), THUS PREVENTING CRH UPREGULATION UNDER CONDITIONS OF CHRONIC STRESS. CPGS MAPPING TO THE NR3C1 CGI SHORE REGION ARE DYNAMICALLY REGULATED BY ELS AND UNDERPIN METHYLATION-SENSITIVE CONTROL OF THIS REGION'S INSULATION-LIKE FUNCTION VIA YING YANG 1 (YY1) BINDING. OUR RESULTS PROVIDE NEW INSIGHT INTO HOW A GENOMIC ELEMENT INTEGRATES EXPERIENCE-DEPENDENT EPIGENETIC PROGRAMMING OF THE COMPOSITE PROXIMAL NR3C1 PROMOTER, AND ASSIGNS AN INSULATING ROLE TO THE CGI SHORE. 2015 5 193 26 ACETYLATION-MEDIATED EPIGENETIC REGULATION OF GLUCOCORTICOID RECEPTOR ACTIVITY: CIRCADIAN RHYTHM-ASSOCIATED ALTERATIONS OF GLUCOCORTICOID ACTIONS IN TARGET TISSUES. GLUCOCORTICOIDS INFLUENCE ORGAN FUNCTIONS THROUGH THE GLUCOCORTICOID RECEPTOR, A PROTEIN ACETYLATED AND DEACETYLATED BY SEVERAL HISTONE ACETYLTRANSFERASES AND DEACETYLASES. WE REPORTED THAT THE CIRCADIAN RHYTHM-RELATED TRANSCRIPTION FACTOR "CLOCK", A KEY COMPONENT OF THE BIOLOGICAL CLOCK WITH INHERENT HISTONE ACETYLTRANSFERASE ACTIVITY, ACETYLATES GLUCOCORTICOID RECEPTOR LYSINES WITHIN ITS HINGE REGION--A "LYSINE CLUSTER" CONTAINING A KXKK MOTIF--AND REPRESSES ITS TRANSCRIPTIONAL ACTIVITY. THIS CLOCK-INDUCED REPRESSION OF THE GLUCOCORTICOID RECEPTOR ACTIVITY IS INVERSELY PHASED TO THE DIURNALLY CIRCULATING GLUCOCORTICOIDS AND MAY ACT AS A LOCAL COUNTER REGULATORY MECHANISM TO THE ACTIONS OF THESE HORMONES. IMPORTANTLY, UNCOUPLING OF THE CENTRAL CLOCK-REGULATED HYPOTHALAMIC-PITUITARY-ADRENAL AXIS AND PERIPHERAL CLOCK-MEDIATED ALTERATIONS OF GLUCOCORTICOID ACTION, SUCH AS CHRONIC STRESS AND FREQUENT TRANS-TIME ZONE TRAVEL OR NIGHT-SHIFT WORK, MAY CAUSE FUNCTIONAL HYPERCORTISOLISM AND CONTRIBUTE TO VARIOUS PATHOLOGIES. THUS, ACETYLATION-MEDIATED EPIGENETIC REGULATION OF THE GLUCOCORTICOID RECEPTOR MAY BE ESSENTIAL FOR THE MAINTENANCE OF PROPER TIME-INTEGRATED GLUCOCORTICOID ACTION, SIGNIFICANTLY INFLUENCING HUMAN WELL-BEING AND LONGEVITY. 2011 6 1884 24 ENDOCANNABINOID-EPIGENETIC CROSS-TALK: A BRIDGE TOWARD STRESS COPING. THERE IS NO ARGUMENT WITH REGARD TO THE PHYSICAL AND PSYCHOLOGICAL STRESS-RELATED NATURE OF NEUROPSYCHIATRIC DISORDERS. YET, THE MECHANISMS THAT FACILITATE DISEASE ONSET STARTING FROM MOLECULAR STRESS RESPONSES ARE ELUSIVE. ENVIRONMENTAL STRESS CHALLENGES INDIVIDUALS' EQUILIBRIUM, ENHANCING HOMEOSTATIC REQUEST IN THE ATTEMPT TO STEER DOWN AROUSAL-INSTRUMENTAL MOLECULAR PATHWAYS THAT UNDERLIE HYPERVIGILANCE AND ANXIETY. A RELEVANT HOMEOSTATIC PATHWAY IS THE ENDOCANNABINOID SYSTEM (ECS). IN THIS REVIEW, WE SUMMARIZE RECENT DISCOVERIES UNAMBIGUOUSLY LISTING ECS AS A STRESS COPING MECHANISM. AS STRESS EVOKES HUGE EXCITATORY RESPONSES IN EMOTIONAL-RELEVANT LIMBIC AREAS, THE ECS LIMITS GLUTAMATE RELEASE VIA 2-ARACHYDONILGLYCEROL (2-AG) STRESS-INDUCED SYNTHESIS AND RETROGRADE CANNABINOID 1 (CB1)-RECEPTOR ACTIVATION AT THE SYNAPSE. HOWEVER, ECS SHOWS INTRINSIC VULNERABILITY AS 2-AG OVERSTIMULATION BY CHRONIC STRESS RAPIDLY LEADS TO CB1-RECEPTOR DESENSITIZATION. IN THIS REVIEW, WE EMPHASIZE THE PROTECTIVE ROLE OF 2-AG IN STRESS-RESPONSE TERMINATION AND STRESS RESILIENCY. INTERESTINGLY, WE DISCUSS ECS REGULATION WITH A FURTHER NUCLEAR HOMEOSTATIC SYSTEM WHOSE NATURE IS EXQUISITELY EPIGENETIC, ORCHESTRATED BY LYSINE SPECIFIC DEMETHYLASE 1. WE HERE EMPHASIZE A REMARKABLE EXAMPLE OF STRESS-COPING NETWORK WHERE TRANSCRIPTIONAL HOMEOSTASIS SUBSERVES SYNAPTIC AND BEHAVIORAL ADAPTATION, AIMING AT REDUCING PSYCHIATRIC EFFECTS OF TRAUMATIC EXPERIENCES. 2020 7 4118 31 MECHANISMS OF BRAIN GLUCOCORTICOID RESISTANCE IN STRESS-INDUCED PSYCHOPATHOLOGIES. EXPOSURE TO STRESS ACTIVATES THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS AND LEADS TO INCREASED LEVELS OF GLUCOCORTICOID (GC) HORMONES. PROLONGED ELEVATION OF GC LEVELS CAUSES NEURONAL DYSFUNCTION, DECREASES THE DENSITY OF SYNAPSES, AND IMPAIRS NEURONAL PLASTICITY. DECREASED SENSITIVITY TO GLUCOCORTICOIDS (GLUCOCORTICOID RESISTANCE) THAT DEVELOPS AS A RESULT OF CHRONIC STRESS IS ONE OF THE CHARACTERISTIC FEATURES OF STRESS-INDUCED PSYCHOPATHOLOGIES. IN THIS ARTICLE, WE REVIEWED THE PUBLISHED DATA ON PROPOSED MOLECULAR MECHANISMS THAT CONTRIBUTE TO THE DEVELOPMENT OF GLUCOCORTICOID RESISTANCE IN BRAIN, INCLUDING CHANGES IN THE EXPRESSION OF THE GLUCOCORTICOID RECEPTOR (GR) GENE, BIOSYNTHESIS OF GR ISOFORMS, AND GR POSTTRANSLATIONAL MODIFICATIONS. WE ALSO PRESENT DATA ON ALTERATIONS IN THE EXPRESSION OF THE FKBP5 GENE ENCODING THE MAIN COMPONENT OF CELL ULTRA-SHORT NEGATIVE FEEDBACK LOOP OF GC SIGNALING REGULATION. RECENT DISCOVERIES ON STRESS- AND GR-INDUCED CHANGES IN EPIGENETIC MODIFICATION PATTERNS AS WELL AS NORMALIZING ACTION OF ANTIDEPRESSANTS ARE DISCUSSED. GR AND FKBP5 GENE POLYMORPHISMS ASSOCIATED WITH STRESS-INDUCED PSYCHOPATHOLOGIES ARE DESCRIBED, AND THEIR ROLE IN GLUCOCORTICOID RESISTANCE IS DISCUSSED. 2017 8 5967 27 TERMINATION OF ACUTE STRESS RESPONSE BY THE ENDOCANNABINOID SYSTEM IS REGULATED THROUGH LYSINE-SPECIFIC DEMETHYLASE 1-MEDIATED TRANSCRIPTIONAL REPRESSION OF 2-AG HYDROLASES ABHD6 AND MAGL. ACUTE ENVIRONMENTAL STRESS RARELY IMPLIES LONG-LASTING NEUROPHYSIOLOGICAL AND BEHAVIORAL ALTERATIONS. ON THE CONTRARY, CHRONIC STRESS EXERTS A POTENT TOXIC EFFECT AT THE GLUTAMATERGIC SYNAPSE WHOSE ALTERED PHYSIOLOGY HAS BEEN RECOGNIZED AS A CORE TRAIT OF NEUROPSYCHIATRIC DISORDERS. THE ENDOCANNABINOID SYSTEM (ECS) PLAYS AN IMPORTANT ROLE IN THE HOMEOSTATIC RESPONSE TO ACUTE STRESS. IN PARTICULAR, STRESS INDUCES SYNTHESIS OF ENDOCANNABINOID (ECB) 2-ARACHIDONYL GLYCEROL (2-AG). 2-AG STIMULATES PRESYNAPTIC CANNABINOID 1 (CB1) RECEPTOR CONTRIBUTING TO STRESS RESPONSE TERMINATION THROUGH INHIBITION OF GLUTAMATE RELEASE, RESTRAINING THEREAFTER ANXIETY AROUSAL. WE EMPLOY MOUSE MODELS OF STRESS RESPONSE COUPLED TO GENE EXPRESSION ANALYSES, UNRAVELLING THAT IN RESPONSE TO ACUTE PSYCHOSOCIAL STRESS IN THE MOUSE HIPPOCAMPUS, ECS-MEDIATED SYNAPTIC MODULATION IS ENHANCED VIA TRANSCRIPTIONAL REPRESSION OF TWO ENZYMES INVOLVED IN 2-AG DEGRADATION: ALPHA/BETA-HYDROLASE DOMAIN CONTAINING 6 (ABHD6) AND MONOACYLGLYCEROL LIPASE (MAGL). SUCH A PROCESS IS ORCHESTRATED BY THE EPIGENETIC COREPRESSOR LSD1 WHO DIRECTLY INTERACTS WITH PROMOTER REGULATORY REGIONS OF ABHD6 AND MAGL. REMARKABLY, NEGATIVE TRANSCRIPTIONAL CONTROL OF ABHD6 AND MAGL IS LOST IN THE HIPPOCAMPUS UPON CHRONIC PSYCHOSOCIAL STRESS, POSSIBLY CONTRIBUTING TO TRAUMA-INDUCED DRIFT OF SYNAPSE PHYSIOLOGY TOWARD UNCONTROLLED GLUTAMATE TRANSMISSION. WE PREVIOUSLY SHOWED THAT IN MICE LYSINE-SPECIFIC DEMETHYLASE 1 (LSD1) INCREASES ITS HIPPOCAMPAL EXPRESSION IN RESPONSE TO PSYCHOSOCIAL STRESS PREVENTING EXCESSIVE CONSOLIDATION OF ANXIETY-RELATED PLASTICITY. IN THIS WORK, WE UNRAVEL A NODAL EPIGENETIC MODULATION OF ECB TURN OVER, SHEDDING NEW LIGHT ON THE MOLECULAR SUBSTRATE OF CONVERGING STRESS-TERMINATING EFFECTS DISPLAYED BY ECS AND LSD1. 2020 9 3092 32 GENOMIC AND EPIGENOMIC MECHANISMS OF GLUCOCORTICOIDS IN THE BRAIN. FOLLOWING THE DISCOVERY OF GLUCOCORTICOID RECEPTORS IN THE HIPPOCAMPUS AND OTHER BRAIN REGIONS, RESEARCH HAS FOCUSED ON UNDERSTANDING THE EFFECTS OF GLUCOCORTICOIDS IN THE BRAIN AND THEIR ROLE IN REGULATING EMOTION AND COGNITION. GLUCOCORTICOIDS ARE ESSENTIAL FOR ADAPTATION TO STRESSORS (ALLOSTASIS) AND IN MALADAPTATION RESULTING FROM ALLOSTATIC LOAD AND OVERLOAD. ALLOSTATIC OVERLOAD, WHICH CAN OCCUR DURING CHRONIC STRESS, CAN RESHAPE THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS THROUGH EPIGENETIC MODIFICATION OF GENES IN THE HIPPOCAMPUS, HYPOTHALAMUS AND OTHER STRESS-RESPONSIVE BRAIN REGIONS. GLUCOCORTICOIDS EXERT THEIR EFFECTS ON THE BRAIN THROUGH GENOMIC MECHANISMS THAT INVOLVE BOTH GLUCOCORTICOID RECEPTORS AND MINERALOCORTICOID RECEPTORS DIRECTLY BINDING TO DNA, AS WELL AS BY NON-GENOMIC MECHANISMS. FURTHERMORE, GLUCOCORTICOIDS SYNERGIZE BOTH GENOMICALLY AND NON-GENOMICALLY WITH NEUROTRANSMITTERS, NEUROTROPHIC FACTORS, SEX HORMONES AND OTHER STRESS MEDIATORS TO SHAPE AN ORGANISM'S PRESENT AND FUTURE RESPONSES TO A STRESSFUL ENVIRONMENT. HERE, WE DISCUSS THE MECHANISMS OF GLUCOCORTICOID ACTION IN THE BRAIN AND REVIEW HOW GLUCOCORTICOIDS INTERACT WITH STRESS MEDIATORS IN THE CONTEXT OF ALLOSTASIS, ALLOSTATIC LOAD AND STRESS-INDUCED NEUROPLASTICITY. 2017 10 3463 30 HYPOTHALAMIC-PITUITARY-ADRENAL AND HYPOTHALAMIC-PITUITARY-GONADAL AXES: SEX DIFFERENCES IN REGULATION OF STRESS RESPONSIVITY. GONADAL HORMONES PLAY A KEY ROLE IN THE ESTABLISHMENT, ACTIVATION, AND REGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS. BY INFLUENCING THE RESPONSE AND SENSITIVITY TO RELEASING FACTORS, NEUROTRANSMITTERS, AND HORMONES, GONADAL STEROIDS HELP ORCHESTRATE THE GAIN OF THE HPA AXIS TO FINE-TUNE THE LEVELS OF STRESS HORMONES IN THE GENERAL CIRCULATION. FROM EARLY LIFE TO ADULTHOOD, GONADAL STEROIDS CAN DIFFERENTIALLY AFFECT THE HPA AXIS, RESULTING IN SEX DIFFERENCES IN THE RESPONSIVITY OF THIS AXIS. THE HPA AXIS INFLUENCES MANY PHYSIOLOGICAL FUNCTIONS MAKING AN ORGANISM'S RESPONSE TO CHANGES IN THE ENVIRONMENT APPROPRIATE FOR ITS REPRODUCTIVE STATUS. ALTHOUGH THE ACUTE HPA RESPONSE TO STRESSORS IS A BENEFICIAL RESPONSE, CONSTANT ACTIVATION OF THIS CIRCUITRY BY CHRONIC OR TRAUMATIC STRESSFUL EPISODES MAY LEAD TO A DYSREGULATION OF THE HPA AXIS AND CAUSE PATHOLOGY. COMPARED TO MALES, FEMALE MICE AND RATS SHOW A MORE ROBUST HPA AXIS RESPONSE, AS A RESULT OF CIRCULATING ESTRADIOL LEVELS WHICH ELEVATE STRESS HORMONE LEVELS DURING NON-THREATENING SITUATIONS, AND DURING AND AFTER STRESSORS. FLUCTUATING LEVELS OF GONADAL STEROIDS IN FEMALES ACROSS THE ESTROUS CYCLE ARE A MAJOR FACTOR CONTRIBUTING TO SEX DIFFERENCES IN THE ROBUSTNESS OF HPA ACTIVITY IN FEMALES COMPARED TO MALES. MOREOVER, GONADAL STEROIDS MAY ALSO CONTRIBUTE TO EPIGENETIC AND ORGANIZATIONAL INFLUENCES ON THE HPA AXIS EVEN BEFORE PUBERTY. CORRESPONDINGLY, CROSSTALK BETWEEN THE HYPOTHALAMIC-PITUITARY-GONADAL (HPG) AND HPA AXES COULD LEAD TO ABNORMALITIES OF STRESS RESPONSES. IN HUMANS, A DYSREGULATED STRESS RESPONSE IS ONE OF THE MOST COMMON SYMPTOMS SEEN ACROSS MANY NEUROPSYCHIATRIC DISORDERS, AND AS A RESULT, SUCH INTERACTIONS MAY EXACERBATE PERIPHERAL PATHOLOGIES. IN THIS REVIEW, WE DISCUSS THE HPA AND HPG AXES AND REVIEW HOW GONADAL STEROIDS INTERACT WITH THE HPA AXIS TO REGULATE THE STRESS CIRCUITRY DURING ALL STAGES IN LIFE. 2017 11 5705 29 SINGLE-CELL TRANSCRIPTIONAL CHANGES IN HYPOTHALAMIC CORTICOTROPIN-RELEASING FACTOR-EXPRESSING NEURONS AFTER EARLY-LIFE ADVERSITY INFORM ENDURING ALTERATIONS IN VULNERABILITIES TO STRESS. BACKGROUND: MENTAL HEALTH AND VULNERABILITIES TO NEUROPSYCHIATRIC DISORDERS INVOLVE THE INTERPLAY OF GENES AND ENVIRONMENT, PARTICULARLY DURING SENSITIVE DEVELOPMENTAL PERIODS. EARLY-LIFE ADVERSITY (ELA) AND STRESS PROMOTE VULNERABILITIES TO STRESS-RELATED AFFECTIVE DISORDERS, YET IT IS UNKNOWN HOW TRANSIENT ELA DICTATES LIFELONG NEUROENDOCRINE AND BEHAVIORAL REACTIONS TO STRESS. THE POPULATION OF HYPOTHALAMIC CORTICOTROPIN-RELEASING FACTOR (CRF)-EXPRESSING NEURONS THAT REGULATE STRESS RESPONSES IS A PROMISING CANDIDATE TO MEDIATE THE LONG-LASTING INFLUENCES OF ELA ON STRESS-RELATED BEHAVIORAL AND HORMONAL RESPONSES VIA ENDURING TRANSCRIPTIONAL AND EPIGENETIC MECHANISMS. METHODS: CAPITALIZING ON A WELL-CHARACTERIZED MODEL OF ELA, WE EXAMINED ELA-INDUCED CHANGES IN GENE EXPRESSION PROFILES OF CRF-EXPRESSING NEURONS IN THE HYPOTHALAMIC PARAVENTRICULAR NUCLEUS OF DEVELOPING MALE MICE. WE USED SINGLE-CELL RNA SEQUENCING ON ISOLATED CRF-EXPRESSING NEURONS. WE DETERMINED THE ENDURING FUNCTIONAL CONSEQUENCES OF TRANSCRIPTIONAL CHANGES ON STRESS REACTIVITY IN ADULT ELA MICE, INCLUDING HORMONAL RESPONSES TO ACUTE STRESS, ADRENAL WEIGHTS AS A MEASURE OF CHRONIC STRESS, AND BEHAVIORS IN THE LOOMING SHADOW THREAT TASK. RESULTS: SINGLE-CELL TRANSCRIPTOMICS IDENTIFIED DISTINCT AND NOVEL CRF-EXPRESSING NEURONAL POPULATIONS, CHARACTERIZED BY BOTH THEIR GENE EXPRESSION REPERTOIRE AND THEIR NEUROTRANSMITTER PROFILES. ELA-PROVOKED EXPRESSION CHANGES WERE SELECTIVE TO SPECIFIC SUBPOPULATIONS AND AFFECTED GENES INVOLVED IN NEURONAL DIFFERENTIATION, SYNAPSE FORMATION, ENERGY METABOLISM, AND CELLULAR RESPONSES TO STRESS AND INJURY. IMPORTANTLY, THESE EXPRESSION CHANGES WERE IMPACTFUL, APPARENT FROM ADRENAL HYPERTROPHY AND AUGMENTED BEHAVIORAL RESPONSES TO STRESS IN ADULTHOOD. CONCLUSIONS: WE UNCOVER A NOVEL REPERTOIRE OF STRESS-REGULATING CRF CELL TYPES DIFFERENTIALLY AFFECTED BY ELA AND RESULTING IN AUGMENTED STRESS VULNERABILITY, WITH RELEVANCE TO THE ORIGINS OF STRESS-RELATED AFFECTIVE DISORDERS. 2023 12 5815 34 STRESS AND GLUCOCORTICOID RECEPTOR TRANSCRIPTIONAL PROGRAMMING IN TIME AND SPACE: IMPLICATIONS FOR THE BRAIN-GUT AXIS. BACKGROUND: CHRONIC PSYCHOLOGICAL STRESS IS ASSOCIATED WITH ENHANCED ABDOMINAL PAIN AND ALTERED INTESTINAL BARRIER FUNCTION THAT MAY RESULT FROM A PERTURBATION IN THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS. THE GLUCOCORTICOID RECEPTOR (GR) EXPLOITS DIVERSE MECHANISMS TO ACTIVATE OR SUPPRESS CONGENERIC GENE EXPRESSION, WITH REGULATORY VARIATION ASSOCIATED WITH STRESS-RELATED DISORDERS IN PSYCHIATRY AND GASTROENTEROLOGY. PURPOSE: DURING ACUTE AND CHRONIC STRESS, CORTICOTROPIN-RELEASING HORMONE DRIVES SECRETION OF ADRENOCORTICOTROPIC HORMONE FROM THE PITUITARY, ULTIMATELY LEADING TO THE RELEASE OF CORTISOL (HUMAN) AND CORTICOSTERONE (RODENT) FROM THE ADRENAL GLANDS. CORTISOL BINDS WITH THE GR IN THE CYTOSOL, TRANSLOCATES TO THE NUCLEUS, AND ACTIVATES THE NR3C1 (NUCLEAR RECEPTOR SUBFAMILY 3, GROUP C, MEMBER 1 [GR]) GENE. THIS REVIEW FOCUSES ON THE RAPIDLY DEVELOPING OBSERVATIONS THAT CORTISOL IS RESPONSIBLE FOR DRIVING CIRCADIAN AND ULTRADIAN BURSTS OF TRANSCRIPTIONAL ACTIVITY IN THE CLOCK (CLOCK CIRCADIAN REGULATOR) AND PER (PERIOD CIRCADIAN CLOCK 1) GENE FAMILIES, AND THIS RHYTHM IS DISRUPTED IN MAJOR DEPRESSIVE DISORDER, BIPOLAR DISORDER, AND STRESS-RELATED GASTROINTESTINAL AND IMMUNE DISORDERS. GLUCOCORTICOID RECEPTOR REGULATES DIFFERENT SETS OF TRANSCRIPTS IN A TISSUE-SPECIFIC MANNER, THROUGH PULSATILE WAVES OF GENE EXPRESSION THAT INCLUDES OCCUPANCY OF GLUCOCORTICOID RESPONSE ELEMENTS LOCATED WITHIN CONSTITUTIVELY OPEN SPATIAL DOMAINS IN CHROMATIN. EMERGING EVIDENCE SUPPORTS A POTENTIALLY PIVOTAL ROLE FOR EPIGENETIC REGULATION OF HOW GR INTERACTS WITH OTHER CHROMATIN REGULATORS TO CONTROL THE EXPRESSION OF ITS TARGET GENES. DYSREGULATION OF THE CENTRAL AND PERIPHERAL GR REGULOME HAS POTENTIALLY SIGNIFICANT CONSEQUENCES FOR STRESS-RELATED DISORDERS AFFECTING THE BRAIN-GUT AXIS. 2016 13 994 22 CHRONIC STRESS INDUCES SEX-SPECIFIC ALTERATIONS IN METHYLATION AND EXPRESSION OF CORTICOTROPIN-RELEASING FACTOR GENE IN THE RAT. BACKGROUND: ALTHOUGH THE HIGHER PREVALENCE OF DEPRESSION IN WOMEN THAN IN MEN IS WELL KNOWN, THE NEURONAL BASIS OF THIS SEX DIFFERENCE IS LARGELY ELUSIVE. METHODS: MALE AND FEMALE RATS WERE EXPOSED TO CHRONIC VARIABLE MILD STRESS (CVMS) AFTER WHICH IMMEDIATE EARLY GENE PRODUCTS, CORTICOTROPIN-RELEASING FACTOR (CRF) MRNA AND PEPTIDE, VARIOUS EPIGENETIC-ASSOCIATED ENZYMES AND DNA METHYLATION OF THE CRF GENE WERE DETERMINED IN THE HYPOTHALAMIC PARAVENTRICULAR NUCLEUS (PVN), OVAL (BSTOV) AND FUSIFORM (BSTFU) PARTS OF THE BED NUCLEUS OF THE STRIA TERMINALIS, AND CENTRAL AMYGDALA (CEA). RESULTS: CVMS INDUCED SITE-SPECIFIC CHANGES IN CRF GENE METHYLATION IN ALL BRAIN CENTERS STUDIED IN FEMALE RATS AND IN THE MALE BST AND CEA, WHEREAS THE HISTONE ACETYLTRANSFERASE, CREB-BINDING PROTEIN WAS INCREASED IN THE FEMALE BST AND THE HISTONE-DEACETYLASE-5 DECREASED IN THE MALE CEA. THESE CHANGES WERE ACCOMPANIED BY AN INCREASED AMOUNT OF C-FOS IN THE PVN, BSTFU AND CEA IN MALES, AND OF FOSB IN THE PVN OF BOTH SEXES AND IN THE MALE BSTOV AND BSTFU. IN THE PVN, CVMS INCREASED CRF MRNA IN MALES AND CRF PEPTIDE DECREASED IN FEMALES. CONCLUSIONS: THE DATA CONFIRM OUR HYPOTHESIS THAT CHRONIC STRESS AFFECTS GENE EXPRESSION AND CRF TRANSCRIPTIONAL, TRANSLATIONAL AND SECRETORY ACTIVITIES IN THE PVN, BSTOV, BSTFU AND CEA, IN A BRAIN CENTER-SPECIFIC AND SEX-SPECIFIC MANNER. BRAIN REGION-SPECIFIC AND SEX-SPECIFIC CHANGES IN EPIGENETIC ACTIVITY AND NEURONAL ACTIVATION MAY PLAY, TOO, AN IMPORTANT ROLE IN THE SEX SPECIFICITY OF THE STRESS RESPONSE AND THE SUSCEPTIBILITY TO DEPRESSION. 2011 14 6267 31 THE NEUROENDOCRINOLOGY OF STRESS: A NEVER ENDING STORY. EVOLUTIONARY SUCCESS DEPENDS ON OUR ABILITY TO ADAPT TO CHANGING CIRCUMSTANCES. THE NEUROENDOCRINE RESPONSE TO STRESS IS AN EXCELLENT EXAMPLE OF A PLASTIC SYSTEM THAT RESPONDS TO THREATS TO HOMEOSTASIS AND ALTERS ITS OUTPUT TO MEET CURRENT AND EXPECTED FUTURE DEMANDS. AT THE LEVEL OF THE HYPOTHALAMUS, THE CORTICOTROPH SECRETAGOGUES CORTICOTROPHIN-RELEASING HORMONE (CRH) AND ARGININE VASOPRESSIN (AVP) RESPOND RAPIDLY TO AN ACUTE STRESSOR BUT, FOLLOWING CHRONIC STRESS, THEY ADAPT WITH A REDUCTION OF CRH BUT A MAJOR INCREASE IN AVP. THE RELEASE OF CRH AND AVP ACTIVATES PRO-OPIOMELANOCORTIN IN ANTERIOR PITUITARY CORTICOTROPH CELLS AND THE RELEASE OF ADRENOCORTICOTROPHIC HORMONE INTO PERIPHERAL BLOOD FROM WHERE IT TARGETS RECEPTORS IN THE ADRENAL CORTEX TO RELEASE GLUCOCORTICOID HORMONES. THESE HORMONES (I.E. CORTICOSTERONE IN THE RAT AND CORTISOL IN MAN) ARE RELEASED IN A PULSATILE ULTRADIAN PATTERN WHICH DEFINES THE NORMAL CIRCADIAN RHYTHM. THE FREQUENCY OF THE PULSES IS INCREASED UNDER STATES OF CHRONIC STRESS, AND IN RATS WITH GENETICALLY DETERMINED HYPER-RESPONSIVENESS OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. INTERESTINGLY, NEONATAL INFLUENCES CAN ALSO PROGRAMME ALTERATIONS IN ULTRADIAN RHYTHMICITY, IMPLICATING EPIGENETIC FACTORS IN ITS REGULATION. AT THE LEVEL OF TISSUE RECEPTORS, THE ALTERATION IN PATTERN OF GLUCOCORTICOID ULTRADIAN RHYTHM HAS DIFFERENTIAL EFFECTS ON MINERALOCORTICOID RECEPTOR AND GLUCOCORTICOID RECEPTOR (GR) BINDING TO DNA AND OFFERS A MECHANISM FOR TISSUE SPECIFIC RESPONSES TO ALTERED GLUCOCORTICOID DYNAMICS. THE EFFECTS OF NEONATAL EXPERIENCE ARE NOT ONLY SEEN AT THE LEVEL OF CRH AND GR REGULATION, BUT ALSO ARE EVIDENT IN BEHAVIOURAL RESPONSES TO STRESS AND IN THE RESPONSIVENESS OF BRAIN STEM SEROTONERGIC PATHWAYS, AS MEASURED BY TRYPTOPHAN HYDROXYLASE MRNA IN THE BRAIN STEM. 2008 15 5834 24 STRESS-INDUCED VISCERAL PAIN IN FEMALE RATS IS ASSOCIATED WITH EPIGENETIC REMODELING IN THE CENTRAL NUCLEUS OF THE AMYGDALA. STRESS AND ANXIETY CONTRIBUTE TO THE PATHOPHYSIOLOGY OF IRRITABLE BOWEL SYNDROME (IBS), A FEMALE-PREDOMINANT DISORDER OF THE GUT-BRAIN AXIS, CHARACTERIZED BY ABDOMINAL PAIN DUE TO HEIGHTENED VISCERAL SENSITIVITY. IN THE CURRENT STUDY, WE AIMED TO EVALUATE IN FEMALE RATS WHETHER EPIGENETIC REMODELING IN THE LIMBIC BRAIN, SPECIFICALLY IN THE CENTRAL NUCLEUS OF THE AMYGDALA (CEA), IS A CONTRIBUTING FACTOR IN STRESS-INDUCED VISCERAL HYPERSENSITIVITY. OUR RESULTS SHOWED THAT 1 H EXPOSURE TO WATER AVOIDANCE STRESS (WAS) FOR 7 CONSECUTIVE DAYS DECREASED HISTONE ACETYLATION AT THE GR PROMOTER AND INCREASED HISTONE ACETYLATION AT THE CRH PROMOTER IN THE CEA. CHANGES IN HISTONE ACETYLATION WERE MEDIATED BY THE HISTONE DEACETYLASE (HDAC) SIRT-6 AND THE HISTONE ACETYLTRANSFERASE CBP, RESPECTIVELY. ADMINISTRATION OF THE HDAC INHIBITOR TRICHOSTATIN A (TSA) INTO THE CEA PREVENTED STRESS-INDUCED VISCERAL HYPERSENSITIVITY THROUGH BLOCKADE OF SIRT-6 MEDIATED HISTONE ACETYLATION AT THE GR PROMOTER. IN ADDITION, HDAC INHIBITION WITHIN THE CEA PREVENTED STRESS-INDUCED HISTONE ACETYLATION OF THE CRH PROMOTER. OUR RESULTS SUGGEST THAT, IN FEMALES, EPIGENETIC MODIFICATIONS IN THE LIMBIC BRAIN REGULATING GR AND CRH EXPRESSION CONTRIBUTE TO STRESS-INDUCED VISCERAL HYPERSENSITIVITY AND OFFER A POTENTIAL EXPLANATION OF HOW STRESS CAN TRIGGER SYMPTOMS IN IBS PATIENTS. 2021 16 204 24 ACTIVATION OF HDAC4 AND GR SIGNALING CONTRIBUTES TO STRESS-INDUCED HYPERALGESIA IN THE MEDIAL PREFRONTAL CORTEX OF RATS. "STRESS-INDUCED HYPERALGESIA (SIH)" IS A PHENOMENON THAT STRESS CAN LEAD TO AN INCREASE IN PAIN SENSITIVITY. EPIGENETIC MECHANISMS HAVE BEEN KNOWN TO PLAY FUNDAMENTAL ROLES IN STRESS AND PAIN. HISTONE ACETYLATION IS AN EPIGENETIC FEATURE THAT IS CHANGED IN NUMEROUS STRESS-RELATED DISEASE SITUATIONS. HOWEVER, EPIGENETIC MECHANISM FOR SIH IS NOT WELL KNOWN. WE INVESTIGATED THE EFFECT OF HISTONE ACETYLATION ON PAIN HYPERSENSITIVITY USING SPS (SINGLE-PROLONGED STRESS) + CFA (COMPLETE FREUND'S ADJUVANT) MODEL. WE SHOWED THAT THE GLUCOCORTICOID RECEPTOR (GR)-PERK-PCREB-FOS SIGNALING PATHWAY WAS UPREGULATED ON STRESS-INDUCED HYPERALGESIA AND THE PAW WITHDRAWAL THRESHOLD IN THE SPS + CFA GROUP DROPPED SIGNIFICANTLY COMPARED WITH THE SPS OR CFA GROUP. HISTONE DEACETYLASES 4 (HDAC4)-EXPRESSING NEURONS IN THE MEDIAL PREFRONTAL CORTEX (MPFC) WERE INCREASED IN THE SPS + CFA-EXPOSED GROUP COMPARED WITH CFA-EXPOSED OR SPS-EXPOSED GROUP. AND WE SHOWED THAT THE EFFECTS OF STRESS-INDUCED HYPERALGESIA WERE CRITICALLY REGULATED VIA REVERSIBLE ACETYLATION (HDAC4) OF THE GR. INHIBITING HDAC4 BY MICROINJECTION OF SODIUM BUTYRATE INTO THE MPFC COULD DISRUPT GLUCOCORTICOID RECEPTOR (GR) SIGNALING PATHWAY, WHICH LOWERED SPS + CFA-CAUSED MECHANICAL ALLODYNIA AND ALLEVIATED ANXIETY-LIKE BEHAVIOR. TOGETHER, OUR STUDIES SUGGEST THAT HDAC INHIBITORS MIGHT INVOLVE IN THE PROCESS OF STRESS-INDUCED HYPERALGESIA. 2020 17 1821 22 EFFECTS OF CHRONIC SOCIAL DEFEAT ON BEHAVIORAL AND NEURAL CORRELATES OF SOCIALITY: VASOPRESSIN, OXYTOCIN AND THE VASOPRESSINERGIC V1B RECEPTOR. CHRONIC SOCIAL STRESS IN RODENTS PRODUCES BEHAVIORAL AND NEUROENDOCRINE PATTERNS ANALOGOUS TO SYMPTOMS ASSOCIATED WITH PSYCHOPATHOLOGIES IN HUMANS. CHRONIC SOCIAL DEFEAT IN MICE HAS BEEN USED TO STUDY THE GENETIC AND EPIGENETIC PRECURSORS OF STRESS-RELATED SOCIAL DISORDERS. THE NEUROPEPTIDES ARGININE VASOPRESSIN (AVP) AND OXYTOCIN (OT) ARE RELEASED IN CENTRAL TARGETS TO MODULATE ANTI- AND PRO-SOCIAL BEHAVIORS, RESPECTIVELY. AVP BINDS TO V1A AND V1B RECEPTORS (V1BRS) IN DISCRETE BRAIN REGIONS RELATED TO ANXIETY, DEPRESSION AND AFFILIATIVE BEHAVIORS. RECENT EVIDENCE SUGGESTS THAT V1BRS ARE INVOLVED IN STRESS AND ANXIETY AND MAY BE AN ATTRACTIVE TARGET FOR THE TREATMENT OF ASSOCIATED DISORDERS. IN THE PRESENT SERIES OF EXPERIMENTS, WE AIMED TO EVALUATE THE EFFECTS OF CHRONIC SOCIAL DEFEAT STRESS ON: 1) ANXIETY-RELATED BEHAVIORS IN A SOCIAL INVESTIGATION PARADIGM AND THEIR POTENTIAL MODULATION BY AN ACUTE DOSE OF SSR149415, A V1BR ANTAGONIST; 2) AVP AND FOS PROTEIN LEVELS IN THE PARAVENTRICULAR NUCLEUS OF THE HYPOTHALAMUS (PVN) AND; 3) AVP- AND OT-RECEPTOR (OTR) MRNA LEVELS IN BRAIN REGIONS ASSOCIATED WITH SOCIALITY. WHEN COMPARED TO UNDEFEATED ANIMALS, SOCIALLY DEFEATED MICE EXHIBITED AN ANXIOGENIC BEHAVIORAL PROFILE TOWARDS A NOVEL MALE CONSPECIFIC, WITH SSR149415 PARTLY ATTENUATING THESE EFFECTS. HISTOCHEMISTRY USING IMMUNOFLUORESCENCE SHOWED DEFEAT PRODUCED SIGNIFICANT ELEVATIONS OF FOS AND DOUBLE LABELING OF AVP AND FOS PROTEINS IN THE PARAVENTRICULAR NUCLEUS OF THE HYPOTHALAMUS (PVN). SSR149415 ATTENUATED THE EFFECTS OF DEFEAT ON FOS AND AVP/FOS DOUBLE LABELING, CONSISTENT WITH AN ANXIOLYTIC EFFECT. DEFEATED MICE SHOWED ELEVATED LEVELS OF OTR MRNA LEVELS IN THE LATERAL SEPTUM (LS) IN ADDITION TO INCREASED V1BR AND OTR MRNA IN THE MEDIAL AMYGDALA (MEA). WE SUGGEST THE INVOLVEMENT OF V1BRS AND OTRS IN A CIRCUIT INVOLVING THE PVN, MEA AND LS IN THE EFFECTS OF DEFEAT ON SOCIALITY. SSR149415 ATTENUATED ANXIOGENESIS IN THE SOCIAL INVESTIGATION MODEL AND BOTH FOS AND AVP/FOS LABELING, SUGGESTING V1BRS ARE AN ATTRACTIVE TARGET FOR THE TREATMENT OF ANXIETY IN GENERAL AND DISORDERS OF SOCIALITY IN PARTICULAR. 2011 18 2905 34 GENE DYSREGULATION IN THE ADULT RAT PARAVENTRICULAR NUCLEUS AND AMYGDALA BY PRENATAL EXPOSURE TO DEXAMETHASONE. FETAL PROGRAMMING IS THE CONCEPT THAT MATERNAL STRESSORS DURING CRITICAL PERIODS OF FETAL DEVELOPMENT CAN ALTER OFFSPRING PHENOTYPES POSTNATALLY. EXCESS GLUCOCORTICOIDS CAN INTERACT WITH THE FETUS TO EFFECT GENETIC AND EPIGENETIC CHANGES IMPLICATED IN ADVERSE DEVELOPMENTAL OUTCOMES. THE PRESENT STUDY INVESTIGATES HOW CHRONIC EXPOSURE TO THE SYNTHETIC GLUCOCORTICOID DEXAMETHASONE DURING LATE GESTATION ALTERS THE EXPRESSION OF GENES RELATED TO BEHAVIOR IN BRAIN AREAS RELEVANT TO THE REGULATION AND FUNCTION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. PREGNANT WISTAR KYOTO RATS RECEIVED SUBCUTANEOUS INJECTIONS OF DEXAMETHASONE (100 MUG/KG) DAILY FROM GESTATIONAL DAY 15-21 OR VEHICLE ONLY AS SHAM CONTROLS. THE AMYGDALA AND PARAVENTRICULAR NUCLEUS (PVN) WERE MICRO-PUNCHED TO EXTRACT MRNA FOR REVERSE TRANSCRIPTION AND QUANTITATIVE POLYMERASE CHAIN REACTION FOR THE ANALYSIS OF THE EXPRESSION OF SPECIFIC GENES. IN THE PVN, THE EXPRESSION OF THE GLUCOCORTICOID RECEPTOR NR3C1 WAS DOWNREGULATED IN FEMALE RATS IN RESPONSE TO PROGRAMMING. THE EXPRESSION OF CACNA1C ENCODING THE CA(V)1.2 PORE SUBUNIT OF L-TYPE VOLTAGE-GATED CALCIUM CHANNELS WAS DOWNREGULATED IN MALE AND FEMALE RATS PRENATALLY EXPOSED TO DEXAMETHASONE. COLLECTIVELY, THE RESULTS SUGGEST THAT PRENATAL EXPOSURE TO ELEVATED LEVELS OF GLUCOCORTICOIDS PLAYS A ROLE IN THE DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS AND POTENTIALLY LEARNING AND MEMORY BY ALTERING THE EXPRESSION OF SPECIFIC GENES WITHIN THE AMYGDALA AND PVN. 2022 19 1774 27 EARLY-LIFE STRESS: FROM NEUROENDOCRINE MECHANISMS TO STRESS-RELATED DISORDERS. STRESS EXPOSURE IS HIGHLY PREVALENT IN THE GENERAL POPULATION; HOWEVER, THE EXPERIENCE OF STRESS DURING VULNERABLE PERIODS OF DEVELOPMENT HAS SUBSTANTIAL AND PERMANENT EFFECTS ON BRAIN STRUCTURE AND FUNCTION AND PHYSICAL HEALTH IN ADULTHOOD. STRESS, THE STATE OF THREATENED HOMEOSTASIS, IS GENERALLY ASSOCIATED WITH A TIME-LIMITED ACTIVATION OF THE STRESS SYSTEM, I.E., THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS AND THE AROUSAL/SYMPATHETIC NERVOUS SYSTEM, TAILORED TO THE STRESSFUL STIMULUS ALSO KNOWN AS THE STRESSOR. ON THE OTHER HAND, CHRONIC STRESS MAY BE ASSOCIATED WITH LINGERING HYPER- OR HYPOSECRETION OF MEDIATORS OF THE STRESS SYSTEM. THIS CHRONIC CONDITION IS CALLED DYSHOMEOSTASIS, ALLOSTASIS, OR CACOSTASIS AND IS ASSOCIATED WITH INCREASED MENTAL AND PHYSICAL MORBIDITY IN THE LONG TERM. STRESSFUL OR TRAUMATIC EXPERIENCES DURING FETAL LIFE, EARLY CHILDHOOD, AND ADOLESCENCE HAVE BEEN RELATED TO PERSISTENT NEUROENDOCRINE AND EPIGENETIC CHANGES. FURTHER, BRAIN STRUCTURES INVOLVED IN THE STRESS RESPONSE, SUCH AS THOSE OF THE STRESS SYSTEM, THE HIPPOCAMPUS, AND THE AMYGDALA, MAY BE PROGRAMMED EARLY ON FOR A LIFE OF ADVERSITY. 2018 20 584 37 BEHAVIORAL NEUROADAPTATION TO ALCOHOL: FROM GLUCOCORTICOIDS TO HISTONE ACETYLATION. A PRIME MECHANISM THAT CONTRIBUTES TO THE DEVELOPMENT AND MAINTENANCE OF ALCOHOLISM IS THE DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS ACTIVITY AND THE RELEASE OF GLUCOCORTICOIDS (CORTISOL IN HUMANS AND PRIMATES, CORTICOSTERONE IN RODENTS) FROM THE ADRENAL GLANDS. IN THE BRAIN, SUSTAINED, LOCAL ELEVATION OF GLUCOCORTICOID CONCENTRATION EVEN LONG AFTER CESSATION OF CHRONIC ALCOHOL CONSUMPTION COMPROMISES FUNCTIONAL INTEGRITY OF A CIRCUIT, INCLUDING THE PREFRONTAL CORTEX (PFC), THE HIPPOCAMPUS (HPC), AND THE AMYGDALA (AMG). THESE STRUCTURES ARE IMPLICATED IN LEARNING AND MEMORY PROCESSES AS WELL AS IN ORCHESTRATING NEUROADAPTIVE RESPONSES TO STRESS AND ANXIETY RESPONSES. THUS, POTENTIATION OF ANXIETY-RELATED NEUROADAPTATION BY ALCOHOL IS CHARACTERIZED BY AN ABNORMALLY AMG HYPERACTIVITY COUPLED WITH A HYPOFUNCTION OF THE PFC AND THE HPC. THIS REVIEW DESCRIBES RESEARCH ON MOLECULAR AND EPIGENETIC MECHANISMS BY WHICH ALCOHOL CAUSES DISTINCT REGION-SPECIFIC ADAPTIVE CHANGES IN GENE EXPRESSION PATTERNS AND ULTIMATELY LEADS TO A VARIETY OF COGNITIVE AND BEHAVIORAL IMPAIRMENTS ON PREFRONTAL- AND HIPPOCAMPAL-BASED TASKS. ALCOHOL-INDUCED NEUROADAPTATIONS INVOLVE THE DYSREGULATION OF NUMEROUS SIGNALING CASCADES, LEADING TO LONG-TERM CHANGES IN TRANSCRIPTIONAL PROFILES OF GENES, THROUGH THE ACTIONS OF TRANSCRIPTION FACTORS SUCH AS [CAMP RESPONSE ELEMENT-BINDING PROTEIN (CREB)] AND CHROMATIN REMODELING DUE TO POSTTRANSLATIONAL MODIFICATIONS OF HISTONE PROTEINS. WE DESCRIBE THE ROLE OF PREFRONTAL-HPC-AMG CIRCUIT IN MEDIATING THE EFFECTS OF ACUTE AND CHRONIC ALCOHOL ON LEARNING AND MEMORY, AND REGION-SPECIFIC MOLECULAR AND EPIGENETIC MECHANISMS INVOLVED IN THIS PROCESS. THIS REVIEW FIRST DISCUSSES THE IMPORTANCE OF BRAIN REGION-SPECIFIC DYSREGULATION OF GLUCOCORTICOID CONCENTRATION IN THE DEVELOPMENT OF ALCOHOL DEPENDENCE AND DESCRIBES HOW PERSISTENTLY INCREASED GLUCOCORTICOID LEVELS IN PFC MAY BE INVOLVED IN MEDIATING WORKING MEMORY IMPAIRMENTS AND NEUROADAPTIVE CHANGES DURING WITHDRAWAL FROM CHRONIC ALCOHOL INTAKE. IT THEN HIGHLIGHTS THE ROLE OF CAMP-PKA-CREB SIGNALING CASCADE AND HISTONE ACETYLATION WITHIN THE PFC AND LIMBIC STRUCTURES IN ALCOHOL-INDUCED ANXIETY AND BEHAVIORAL IMPAIRMENTS, AND HOW AN UNDERSTANDING OF FUNCTIONAL ALTERATIONS OF THESE PATHWAYS MIGHT LEAD TO BETTER TREATMENTS FOR NEUROPSYCHIATRIC DISORDERS. 2016