1 1884 129 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 2 5967 49 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 3 6097 18 THE EFFECTS OF STRESS ON GLUTAMATERGIC TRANSMISSION IN THE BRAIN. STRESS LEADS TO DETRIMENTAL EFFECTS ON BRAIN FUNCTIONS AND RESULTS IN VARIOUS DISEASES. RECENT STUDIES HIGHLIGHT THE INVOLVEMENT OF GLUTAMATERGIC TRANSMISSION IN PATHOGENESIS OF DEPRESSIVE BEHAVIORS AND FEARS. ACUTE STRESS GENERATES DIFFERENT IMPACTS ON THE EXCITATORY TRANSMISSION COMPARED TO CHRONIC STRESS. DIFFERENT NEUROMODULATORS AND EPIGENETIC FACTORS ALSO PARTICIPATE IN THE ALTERATION OF SYNAPTIC TRANSMISSION AND THE REGULATION OF SYNAPTIC PLASTICITY. RESTORATION OF THE GLUTAMATERGIC TRANSMISSION IN STRESS-AFFECTED BRAIN AREAS THEREFORE PROVIDES NOVEL DIRECTIONS OF THERAPEUTIC INTERVENTIONS AGAINST STRESS. 2015 4 4420 30 MOLECULAR AND EPIGENETIC MECHANISMS FOR THE COMPLEX EFFECTS OF STRESS ON SYNAPTIC PHYSIOLOGY AND COGNITIVE FUNCTIONS. EVIDENCE OVER THE PAST DECADES HAS FOUND THAT STRESS, PARTICULARLY THROUGH THE CORTICOSTERONE STRESS HORMONES, PRODUCES COMPLEX CHANGES IN GLUTAMATERGIC SIGNALING IN PREFRONTAL CORTEX, WHICH LEADS TO THE ALTERATION OF COGNITIVE PROCESSES MEDICATED BY THIS BRAIN REGION. INTERESTINGLY, THE EFFECTS OF STRESS ON GLUTAMATERGIC TRANSMISSION APPEAR TO BE "U-SHAPED," DEPENDING UPON THE DURATION AND SEVERITY OF THE STRESSOR. THESE BIPHASIC EFFECTS OF ACUTE VS CHRONIC STRESS REPRESENT THE ADAPTIVE VS MALADAPTIVE RESPONSES TO STRESSFUL STIMULI. ANIMAL STUDIES SUGGEST THAT THE STRESS-INDUCED MODULATION OF EXCITATORY SYNAPTIC TRANSMISSION INVOLVES CHANGES IN PRESYNAPTIC GLUTAMATE RELEASE, POSTSYNAPTIC GLUTAMATE RECEPTOR MEMBRANE TRAFFICKING AND DEGRADATION, SPINE STRUCTURE AND CYTOSKELETON NETWORK, AND EPIGENETIC CONTROL OF GENE EXPRESSION. THIS REVIEW WILL DISCUSS CURRENT FINDINGS ON THE KEY MOLECULES INVOLVED IN THE STRESS-INDUCED REGULATION OF PREFRONTAL CORTEX SYNAPTIC PHYSIOLOGY AND PREFRONTAL CORTEX-MEDIATED FUNCTIONS. UNDERSTANDING THE MOLECULAR AND EPIGENETIC MECHANISMS THAT UNDERLIE THE COMPLEX EFFECTS OF STRESS WILL HELP TO DEVELOP NOVEL STRATEGIES TO COPE WITH STRESS-RELATED MENTAL DISORDERS. 2017 5 3708 27 INFLUENCE OF PHARMACOLOGICAL AND EPIGENETIC FACTORS TO SUPPRESS NEUROTROPHIC FACTORS AND ENHANCE NEURAL PLASTICITY IN STRESS AND MOOD DISORDERS. STRESS-INDUCED MAJOR DEPRESSION AND MOOD DISORDERS ARE CHARACTERIZED BY BEHAVIOURAL ABNORMALITIES AND PSYCHIATRIC ILLNESS, LEADING TO DISABILITY AND IMMATURE MORTALITY WORLDWIDE. NEUROBIOLOGICAL MECHANISMS OF STRESS AND MOOD DISORDERS ARE DISCUSSED CONSIDERING RECENT FINDINGS, AND CHALLENGES TO ENHANCE PHARMACOLOGICAL EFFECTS OF ANTIDEPRESSANT, AND MOOD STABILIZERS. PHARMACOLOGICAL ENHANCEMENT OF KETAMINE AND SCOPOLAMINE REGULATES DEPRESSION AT THE MOLECULAR LEVEL, INCREASING SYNAPTIC PLASTICITY IN PREFRONTAL REGIONS. BLOOD-DERIVED NEUROTROPHIC FACTORS FACILITATE MOOD-DEFICIT SYMPTOMS. EPIGENETIC FACTORS MAINTAIN STRESS-RESILIENCE IN HIPPOCAMPAL REGION. REGULATION OF NEUROTROPHIC FACTORS BLOCKADES STRESS, AND ENHANCES NEURONAL SURVIVAL THOUGH IT PARALYZES LIMBIC REGIONS. MOLECULAR AGENTS AND NEUROTROPHIC FACTORS ALSO CONTROL BEHAVIORAL AND SYNAPTIC PLASTICITY IN ADDICTION AND STRESS DISORDERS. FUTURE RESEARCH ON NEURONAL DYNAMICS AND CELLULAR ACTIONS CAN BE DIRECTED TO OBTAIN THE ETIOLOGY OF SYNAPTIC DYSREGULATION IN MOOD DISORDER AND STRESS. FOR THE FIRST TIME, THE CURRENT REVIEW CONTRIBUTES TO THE LITERATURE OF SYNAPTIC PLASTICITY REPRESENTING THE ROLE OF EPIGENETIC MECHANISMS AND GLUCOCORTICOID RECEPTORS TO PREDICT DEPRESSION AND ANXIETY IN CLINICAL CONDITIONS. 2019 6 6389 31 THE ROLE OF THE ENDOCANNABINOID SYSTEM IN THE BRAIN-GUT AXIS. THE ACTIONS OF CANNABIS ARE MEDIATED BY RECEPTORS THAT ARE PART OF AN ENDOGENOUS CANNABINOID SYSTEM. THE ENDOCANNABINOID SYSTEM (ECS) CONSISTS OF THE NATURALLY OCCURRING LIGANDS N-ARACHIDONOYLETHANOLAMINE (ANANDAMIDE) AND 2-ARACHIDONOYLGLYCEROL (2-AG), THEIR BIOSYNTHETIC AND DEGRADATIVE ENZYMES, AND THE CANNABINOID (CB) RECEPTORS CB1 AND CB2. THE ECS IS A WIDELY DISTRIBUTED TRANSMITTER SYSTEM THAT CONTROLS GUT FUNCTIONS PERIPHERALLY AND CENTRALLY. IT IS AN IMPORTANT PHYSIOLOGIC REGULATOR OF GASTROINTESTINAL MOTILITY. POLYMORPHISMS IN THE GENE ENCODING CB1 (CNR1) HAVE BEEN ASSOCIATED WITH SOME FORMS OF IRRITABLE BOWEL SYNDROME. THE ECS IS INVOLVED IN THE CONTROL OF NAUSEA AND VOMITING AND VISCERAL SENSATION. THE HOMEOSTATIC ROLE OF THE ECS ALSO EXTENDS TO THE CONTROL OF INTESTINAL INFLAMMATION. WE REVIEW THE MECHANISMS BY WHICH THE ECS LINKS STRESS AND VISCERAL PAIN. CB1 IN SENSORY GANGLIA CONTROLS VISCERAL SENSATION, AND TRANSCRIPTION OF CNR1 IS MODIFIED THROUGH EPIGENETIC PROCESSES UNDER CONDITIONS OF CHRONIC STRESS. THESE PROCESSES MIGHT LINK STRESS WITH ABDOMINAL PAIN. THE ECS IS ALSO INVOLVED CENTRALLY IN THE MANIFESTATION OF STRESS, AND ENDOCANNABINOID SIGNALING REDUCES THE ACTIVITY OF HYPOTHALAMIC-PITUITARY-ADRENAL PATHWAYS VIA ACTIONS IN SPECIFIC BRAIN REGIONS, NOTABLY THE PREFRONTAL CORTEX, AMYGDALA, AND HYPOTHALAMUS. AGENTS THAT MODULATE THE ECS ARE IN EARLY STAGES OF DEVELOPMENT FOR TREATMENT OF GASTROINTESTINAL DISEASES. INCREASING OUR UNDERSTANDING OF THE ECS WILL GREATLY ADVANCE OUR KNOWLEDGE OF INTERACTIONS BETWEEN THE BRAIN AND GUT AND COULD LEAD TO NEW TREATMENTS FOR GASTROINTESTINAL DISORDERS. 2016 7 678 30 BRAIN DEVELOPMENT UNDER STRESS: HYPOTHESES OF GLUCOCORTICOID ACTIONS REVISITED. ONE OF THE CONUNDRUMS IN TODAY'S STRESS RESEARCH IS WHY SOME INDIVIDUALS FLOURISH AND OTHERS PERISH UNDER SIMILAR STRESSFUL CONDITIONS. IT IS RECOGNIZED THAT THIS INDIVIDUAL VARIABILITY IN ADAPTATION TO STRESS DEPENDS ON THE OUTCOME OF THE INTERACTION OF GENETIC AND COGNITIVE/EMOTIONAL INPUTS IN WHICH GLUCOCORTICOID HORMONES AND RECEPTORS PLAY A CRUCIAL ROLE. HENCE ONE APPROACH TOWARDS UNDERSTANDING INDIVIDUAL VARIATION IN STRESS COPING IS HOW GLUCOCORTICOID ACTIONS CAN CHANGE FROM PROTECTIVE TO HARMFUL. TO ADDRESS THIS QUESTION WE FOCUS ON FOUR HYPOTHESES THAT ARE CONNECTED AND NOT MUTUAL EXCLUSIVE. FIRST, THE CLASSICAL GLUCOCORTICOID CASCADE HYPOTHESIS, IN WHICH THE INABILITY TO COPE WITH CHRONIC STRESS CAUSES A VICIOUS CYCLE OF EXCESS GLUCOCORTICOID AND DOWNREGULATION OF GLUCOCORTICOID RECEPTORS (GR) IN THE HIPPOCAMPUS TRIGGERING A FEED-FORWARD CASCADE OF DEGENERATION AND DISEASE. SECOND, THE BALANCE HYPOTHESIS, WHICH TAKES ALSO THE LIMBIC MINERALOCORTICOID RECEPTORS (MR) INTO ACCOUNT AND PROPOSES THAT AN INTEGRAL LIMBIC MR:GR IMBALANCE IS CAUSAL TO ALTERED PROCESSING OF INFORMATION IN CIRCUITS UNDERLYING FEAR, REWARD, SOCIAL BEHAVIOUR AND RESILIENCE, DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS AND IMPAIRMENT OF BEHAVIOURAL ADAPTATION. THE MR:GR BALANCE IS ALTERED BY GENE VARIANTS OF THESE RECEPTOR COMPLEXES AND EXPERIENCE-RELATED FACTORS, WHICH CAN INDUCE LASTING EPIGENETIC CHANGES IN THE EXPRESSION OF THESE RECEPTORS. A PARTICULAR POTENT EPIGENETIC STIMULUS IS THE MATERNAL ENVIRONMENT WHICH IS FUNDAMENTAL FOR THE MATERNAL MEDIATION HYPOTHESIS. THE OUTCOME OF PERINATAL GENE X ENVIRONMENT INTERACTION, AND THUS OF MR:GR-MEDIATED FUNCTIONS DEPENDS HOWEVER, ON THE DEGREE OF 'MATCHING' WITH ENVIRONMENTAL DEMANDS IN LATER LIFE. THE PREDICTIVE ADAPTATION HYPOTHESIS THEREFORE PRESENTS A CONCEPTUAL FRAMEWORK TO EXAMINE THE ROLE OF GLUCOCORTICOIDS IN UNDERSTANDING INDIVIDUAL PHENOTYPIC DIFFERENCES IN STRESS-RELATED BEHAVIOURS OVER THE LIFESPAN. 2010 8 1774 29 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 9 4655 31 NEUROTROPHIN MEDIATED HPA AXIS DYSREGULATION IN STRESS INDUCED GENESIS OF PSYCHIATRIC DISORDERS: ORCHESTRATION BY EPIGENETIC MODIFICATIONS. APART FROM THEIR ESTABLISHED ROLE IN EMBRYONIC DEVELOPMENT, NEUROTROPHINS (NTS) HAVE DIVERSE FUNCTIONS IN THE NERVOUS SYSTEM. THEIR ROLE IN THE INTEGRATION OF PHYSIOLOGICAL AND BIOCHEMICAL ASPECTS OF THE NERVOUS SYSTEM IS CURRENTLY ATTRACTING MUCH ATTENTION. BASED ON A SYSTEMATIC ANALYSIS OF THE LITERATURE, WE HERE PROPOSE A NEW PARADIGM THAT, BY EXPLOITING A NOVEL ROLE OF NTS, MAY HELP EXPLAIN THE GENESIS OF STRESS-RELATED PSYCHIATRIC DISORDERS, OPENING NEW AVENUES FOR BETTER MANAGEMENT OF THE SAME. WE HYPOTHESIZE THAT NTS AS AN INTEGRATED NETWORK PLAY A CRUCIAL ROLE IN MAINTAINING AN INDIVDUAL'S PSYCHOLOGICAL WELLBEING. GIVEN THE EVIDENCE THAT STRESS CAN INDUCE CHRONIC DISRUPTION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS WHICH, IN TURN, IS CAUSALLY LINKED TO SEVERAL PSYCHIATRIC DISORDERS, THIS FUNCTION MAY BE MEDIATED THROUGH THE HOMEOSTATIC MECHANISMS GOVERNING REGULATION OF THIS AXIS. IN FACT, NTS, SUCH AS NERVE GROWTH FACTOR (NGF) AND BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) ARE KNOWN TO PARTICIPATE IN NEUROENDOCRINE REGULATION. RECENT STUDIES SUGGEST EPIGENETIC MODIFICATION OF NT-HPA AXIS INTERPLAY IN THE PRECIPITATION OF PSYCHIATRIC DISORDERS. OUR ARTICLE HIGHLIGHTS WHY THIS NEW KNOWLEDGE REGARDING NTS SHOULD BE CONSIDERED IN THE ETIOGENESIS AND TREATMENT OF STRESS-INDUCED PSYCHOPATHOLOGY. 2019 10 1364 31 DEVELOPMENTAL NEUROENDOCRINOLOGY OF EARLY-LIFE STRESS: IMPACT ON CHILD DEVELOPMENT AND BEHAVIOR. OUR INTERNAL BALANCE, OR HOMEOSTASIS, IS THREATENED OR PERCEIVED AS THREATENED BY STRESSFUL STIMULI, THE STRESSORS. THE STRESS SYSTEM IS A HIGHLY CONSERVED SYSTEM THAT ADJUSTS HOMEOSTASIS TO THE RESTING STATE. THROUGH THE CONCURRENT ACTIVATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS AND THE LOCUS COERULEUS/NOREPINEPHRINE-AUTONOMIC NERVOUS SYSTEMS, THE STRESS SYSTEM PROVIDES THE APPROPRIATE PHYSICAL AND BEHAVIORAL RESPONSES, COLLECTIVELY TERMED AS "STRESS RESPONSE", TO RESTORE HOMEOSTASIS. IF THE STRESS RESPONSE IS PROLONGED, EXCESSIVE OR EVEN INADEQUATE, SEVERAL ACUTE OR CHRONIC STRESS-RELATED PATHOLOGIC CONDITIONS MAY DEVELOP IN CHILDHOOD, ADOLESCENCE AND ADULT LIFE. ON THE OTHER HAND, EARLY-LIFE EXPOSURE TO STRESSORS HAS BEEN RECOGNIZED AS A MAJOR CONTRIBUTING FACTOR UNDERLYING THE PATHOGENESIS OF NON-COMMUNICABLE DISORDERS, INCLUDING NEURODEVELOPMENTAL DISORDERS. ACCUMULATING EVIDENCE SUGGESTS THAT EARLY-LIFE STRESS HAS BEEN ASSOCIATED WITH AN INCREASED RISK FOR ATTENTION DEFICIT HYPERACTIVITY DISORDER AND AUTISM SPECTRUM DISORDER IN THE OFFSPRING, ALTHOUGH FINDINGS ARE STILL CONTROVERSIAL. NEVERTHELESS, AT THE MOLECULAR LEVEL, EARLY-LIFE STRESSORS ALTER THE CHEMICAL STRUCTURE OF CYTOSINES LOCAT- ED IN THE REGULATORY REGIONS OF GENES, MOSTLY THROUGH THE ADDITION OF METHYL GROUPS. THESE EPIGENETIC MODIFICATIONS RESULT IN THE SUPPRESSION OF GENE EXPRESSION WITHOUT CHANGING THE DNA SEQUENCE. IN ADDITION TO DNA METHYLATION, SEVERAL LINES OF EVIDENCE SUPPORT THE ROLE OF NON-CODING RNAS IN THE EVOLVING FIELD OF EPIGENETICS. IN THIS REVIEW ARTICLE, WE PRESENT THE ANATOMICAL AND FUNCTIONAL COMPO- NENTS OF THE STRESS SYSTEM, DISCUSS THE PROPER, IN TERMS OF QUALITY AND QUANTITY, STRESS RESPONSE, AND PROVIDE AN UPDATE ON THE IMPACT OF EARLY-LIFE STRESS ON CHILD DEVELOPMENT AND BEHAVIOR. 2023 11 2596 29 EPIGENETICS OF STRESS ADAPTATIONS IN THE BRAIN. RECENT FINDINGS IN EPIGENETICS SHED NEW LIGHT ON THE REGULATION OF GENE EXPRESSION IN THE CENTRAL NERVOUS SYSTEM (CNS) DURING STRESS. THE MOST FREQUENTLY STUDIED EPIGENETIC MECHANISMS ARE DNA METHYLATION, HISTONE MODIFICATIONS AND MICRORNA ACTIVITY. THESE MECHANISMS STABLY DETERMINE CELL PHENOTYPE BUT CAN ALSO BE RESPONSIBLE FOR DYNAMIC MOLECULAR ADAPTATIONS OF THE CNS TO STRESSORS. THE LIMBIC-HYPOTHALAMIC-PITUITARY-ADRENAL AXIS (LHPA) IS THE PRIMARY CIRCUIT THAT INITIATES, REGULATES AND TERMINATES A STRESS RESPONSE. THE SAME BRAIN AREAS THAT CONTROL STRESS ALSO REACT TO STRESS DYNAMICALLY AND WITH LONG-TERM CONSEQUENCES. ONE OF THE BIOLOGICAL PROCESSES EVOKING POTENT ADAPTIVE CHANGES IN THE CNS SUCH AS CHANGES IN BEHAVIOR, GENE ACTIVITY OR SYNAPTIC PLASTICITY IN THE HIPPOCAMPUS IS PSYCHOGENIC STRESS. THIS REVIEW SUMMARIZES THE CURRENT DATA REGARDING THE EPIGENETIC BASIS OF MOLECULAR ADAPTATIONS IN THE BRAIN INCLUDING GENOME-WIDE EPIGENETIC CHANGES OF DNA METHYLATION AND PARTICULAR GENES INVOLVED IN EPIGENETIC RESPONSES THAT PARTICIPATE IN THE BRAIN RESPONSE TO CHRONIC PSYCHOGENIC STRESSORS. IT IS CONCLUDED THAT SPECIFIC EPIGENETIC MECHANISMS IN THE CNS ARE INVOLVED IN THE STRESS RESPONSE. 2013 12 291 28 AGING AND STRESS: PAST HYPOTHESES, PRESENT APPROACHES AND PERSPECTIVES. BRAIN AGING HAS BEEN SUGGESTED TO BE CONDITIONED BY AN EXCESSIVE GLUCOCORTIOID SECRETION LEADING TO DAMAGES ON BRAIN AREAS INVOLVED NOT ONLY IN COGNITIVE AND EMOTIONAL PROCESSES BUT ALSO IN THE CONTROL OF THE ACTIVITY OF THE HYPOTHALAMIC-PITUITARY ADRENAL AXIS. THIS REVIEW DESCRIBES SOME OF THE HYPOTHESIS THAT TRY TO EXPLAIN THE RELATION BETWEEN THE DYSREGULATION OF THE STRESS RESPONSE AND BRAIN AGING, FOCUSING ON CORTICOSTERONE BUT ALSO ON NEUROTRANSMISSION IN THE HIPPOCAMPUS, THE PREFRONTAL CORTEX AND THE AMYGDALA. MOREOVER, DIFFERENT MOLECULAR FACTORS CAN ACCOUNT FOR AN ENHANCED VULNERABILITY OF THE AGED BRAIN TO STRESS EXPOSURE, SPECIALLY FOR RESILIENCE. AMONG THEM, GOOD CANDIDATES COULD BE THOSE MECHANISMS DETERMINING THE LEVELS OF CORTICOSTERONE IN THE BRAIN, SEVERAL MOLECULES DOWNSTREAM GLUCOCORTICOID RECEPTOR ACTIVATION (IE: HEAT SHOCK PROTEINS, BAG-1) OR EVEN THE EPIGENETIC PROGRAMMING OF THE HPA AXIS IN EARLY STAGES. IN CONCLUSION, GENETIC AND ENVIRONMENTAL FACTORS (EARLY LIFE STRESS, CHRONIC STRESS DURING ADULTHOOD) CAN PRODUCE AN ENHANCED VULNERABILITY AND A REDUCED RESILIENCE OF THE BRAIN TO SUBSEQUENT STRESS EXPOSURES OR TO METABOLIC CHALLENGES LEADING, IN TURN, TO AN UNSUCCESSFUL AGING OF THE BRAIN. HOWEVER, RESULTS OBTAINED WITH THE USE OF THE ENVIRONMENTAL ENRICHMENT MODEL IN ANIMALS, ADDED TO SEVERAL RESULTS IN HUMANS ALSO DESCRIBED IN THIS REVIEW SUGGEST THAT POSITIVE ENVIRONMENTAL FACTORS (COGNITIVE-DEMANDING TASKS OR PHYSICAL EXERCISE) CAN HELP TO MAINTAIN NEURONAL PLASTICITY DURING AGING AND TO PROTECT THE BRAIN AGAINST THE DAMAGING EFFECTS OF STRESS EXPOSURE. 2011 13 2386 29 EPIGENETIC REGULATORY MECHANISMS IN STRESS-INDUCED BEHAVIOR. STRESS RESPONSE IS CONSIDERED TO HAVE ADAPTIVE VALUE FOR ORGANISMS FACED WITH STRESSFUL CONDITION. CHRONIC STRESS HOWEVER ADVERSELY AFFECTS THE PHYSIOLOGY AND MAY LEAD TO NEUROPSYCHIATRIC DISORDERS. REPEATED STRESSFUL EVENTS IN ANIMAL MODELS HAVE BEEN SHOWN TO CAUSE LONG-LASTING CHANGES IN NEURAL CIRCUITRIES AT MOLECULAR, CELLULAR, AND PHYSIOLOGICAL LEVEL, LEADING TO DISORDERS OF MOOD AS WELL AS COGNITION. MOLECULAR STUDIES IN RECENT YEARS HAVE IMPLICATED DIVERSE EPIGENETIC MECHANISMS, INCLUDING HISTONE MODIFICATIONS, DNA METHYLATION, AND NONCODING RNAS, THAT UNDERLIE DYSREGULATION OF GENES IN THE AFFECTED NEURAL CIRCUITRIES IN CHRONIC STRESS-INDUCED PATHOPHYSIOLOGY. A REVIEW OF THE MYRIAD EPIGENETIC REGULATORY MECHANISMS ASSOCIATED WITH NEURAL AND BEHAVIORAL RESPONSES IN ANIMAL MODELS OF STRESS-INDUCED NEUROPSYCHIATRIC DISORDERS IS PRESENTED HERE. THE REVIEW ALSO DEALS WITH CLINICAL EVIDENCE OF THE EPIGENETIC DYSREGULATION OF GENES IN PSYCHIATRIC DISORDERS WHERE CHRONIC STRESS APPEARS TO UNDERLIE THE ETIOPATHOLOGY. 2014 14 5310 29 PSYCHOBIOLOGY AND MOLECULAR GENETICS OF RESILIENCE. EVERY INDIVIDUAL EXPERIENCES STRESSFUL LIFE EVENTS. IN SOME CASES ACUTE OR CHRONIC STRESS LEADS TO DEPRESSION AND OTHER PSYCHIATRIC DISORDERS, BUT MOST PEOPLE ARE RESILIENT TO SUCH EFFECTS. RECENT RESEARCH HAS BEGUN TO IDENTIFY THE ENVIRONMENTAL, GENETIC, EPIGENETIC AND NEURAL MECHANISMS THAT UNDERLIE RESILIENCE, AND HAS SHOWN THAT RESILIENCE IS MEDIATED BY ADAPTIVE CHANGES IN SEVERAL NEURAL CIRCUITS INVOLVING NUMEROUS NEUROTRANSMITTER AND MOLECULAR PATHWAYS. THESE CHANGES SHAPE THE FUNCTIONING OF THE NEURAL CIRCUITS THAT REGULATE REWARD, FEAR, EMOTION REACTIVITY AND SOCIAL BEHAVIOUR, WHICH TOGETHER ARE THOUGHT TO MEDIATE SUCCESSFUL COPING WITH STRESS. 2009 15 4144 27 MECHANISMS OF STRESS-INDUCED VISCERAL PAIN. EVIDENCE SUGGESTS THAT LONG-TERM STRESS FACILITATES VISCERAL PAIN THROUGH SENSITIZATION OF PAIN PATHWAYS AND PROMOTES CHRONIC VISCERAL PAIN DISORDERS SUCH AS THE IRRITABLE BOWEL SYNDROME (IBS). THIS REVIEW WILL DESCRIBE THE IMPORTANCE OF STRESS IN EXACERBATING IBS-INDUCED ABDOMINAL PAIN. ADDITIONALLY, WE WILL BRIEFLY REVIEW OUR UNDERSTANDING OF THE ACTIVATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS BY BOTH CHRONIC ADULT STRESS AND FOLLOWING EARLY LIFE STRESS IN THE PATHOGENESIS OF IBS. THE REVIEW WILL FOCUS ON THE GLUCOCORTICOID RECEPTOR AND CORTICOTROPIN-RELEASING HORMONE-MEDIATED MECHANISMS IN THE AMYGDALA INVOLVED IN STRESS-INDUCED VISCERAL HYPERSENSITIVITY. ONE POTENTIAL MECHANISM UNDERLYING PERSISTENT EFFECTS OF STRESS ON VISCERAL SENSITIVITY COULD BE EPIGENETIC MODULATION OF GENE EXPRESSION. WHILE THERE ARE RELATIVELY FEW STUDIES EXAMINING EPIGENETICALLY MEDIATED MECHANISMS INVOLVED IN STRESS-INDUCED VISCERAL NOCICEPTION, ALTERATIONS IN DNA METHYLATION AND HISTONE ACETYLATION PATTERNS WITHIN THE BRAIN, HAVE BEEN LINKED TO ALTERATIONS IN NOCICEPTIVE SIGNALING VIA INCREASED EXPRESSION OF PRO-NOCICEPTIVE NEUROTRANSMITTERS. THIS REVIEW WILL DISCUSS THE LATEST STUDIES INVESTIGATING THE LONG-TERM EFFECTS OF STRESS ON VISCERAL SENSITIVITY. ADDITIONALLY, WE WILL CRITICALLY REVIEW THE IMPORTANCE OF EXPERIMENTAL MODELS OF ADULT STRESS AND EARLY LIFE STRESS IN ENHANCING OUR UNDERSTANDING OF THE BASIC MOLECULAR MECHANISMS OF NOCICEPTIVE PROCESSING. 2018 16 5810 23 STRESS & SLEEP: A RELATIONSHIP LASTING A LIFETIME. STRESS IS AN ADAPTATIVE RESPONSE AIMED AT RESTORING BODY HOMEOSTASIS. THE CLASSICAL NEUROENDOCRINE STRESS RESPONSE INVOLVING THE ACTIVATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS MODULATES MANY PHYSIOLOGICAL ASPECTS, SUCH AS THE WAKE-SLEEP CYCLE. IN THE PRESENT REVIEW, WE WILL FIRST REPORT A SERIES OF HUMAN AND RODENT STUDIES SHOWING THAT EACH ACTOR OF THE HPA AXIS HAS THE POTENTIAL TO INTERFERE WITH SLEEP HOMEOSTASIS AND, THEN, WE WILL HIGHLIGHT HOW ACUTE OR CHRONIC STRESS DIFFERENTLY MODULATES THE WAKE-SLEEP CYCLE. MOREOVER, WE WILL PRESENT NEW AND INTERESTING STUDIES DEALING WITH THE RELATIONSHIP BETWEEN SLEEP AND STRESS ON A DIFFERENT (LONGER) TIME SCALE. PARTICULARLY, WE WILL DISCUSS HOW THE EXPOSURE TO PERINATAL STRESS, PROBABLY THROUGH EPIGENETIC MODULATIONS, IS SUFFICIENT TO CAUSE PERSISTENT SLEEP DERANGEMENTS DURING ADULT LIFE. IN LIGHT OF THIS EVIDENCE, THE MAIN MESSAGE OF THE PRESENT REVIEW IS THAT THE COMPLEX RELATIONSHIP BETWEEN SLEEP AND STRESS CHANGES DRAMATICALLY ON THE BASIS OF THE TIME SCALE CONSIDERED AND, CONSEQUENTLY, "TIME" SHOULD BE CONSIDERED AS A CRITICAL FACTOR WHEN FACING THIS TOPIC. 2020 17 584 34 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 18 4621 27 NEUROBIOLOGICAL AND SYSTEMIC EFFECTS OF CHRONIC STRESS. THE BRAIN IS THE CENTRAL ORGAN OF STRESS AND ADAPTATION TO STRESS BECAUSE IT PERCEIVES AND DETERMINES WHAT IS THREATENING, AS WELL AS THE BEHAVIORAL AND PHYSIOLOGICAL RESPONSES TO THE STRESSOR, WHICH PROMOTE ADAPTATION ("ALLOSTASIS") BUT ALSO CONTRIBUTE TO PATHOPHYSIOLOGY ("ALLOSTATIC LOAD/OVERLOAD") WHEN OVERUSED AND DYSREGULATED. THE ADULT AS WELL AS DEVELOPING BRAIN POSSESSES A REMARKABLE ABILITY TO SHOW STRUCTURAL AND FUNCTIONAL PLASTICITY IN RESPONSE TO STRESSFUL AND OTHER EXPERIENCES, INCLUDING NEURONAL REPLACEMENT, DENDRITIC REMODELING AND SYNAPSE TURNOVER. STRESS CAN CAUSE AN IMBALANCE OF NEURAL CIRCUITRY SUBSERVING COGNITION, DECISION MAKING, ANXIETY AND MOOD THAT CAN INCREASE OR DECREASE EXPRESSION OF THOSE BEHAVIORS AND BEHAVIORAL STATES. THIS IMBALANCE, IN TURN, AFFECTS SYSTEMIC PHYSIOLOGY VIA NEUROENDOCRINE, AUTONOMIC, IMMUNE AND METABOLIC MEDIATORS. IN THE SHORT TERM, THESE CHANGES MAY BE ADAPTIVE; BUT, IF THE THREAT PASSES AND THE BEHAVIORAL STATE PERSISTS ALONG WITH THE CHANGES IN NEURAL CIRCUITRY, SUCH MALADAPTATION REQUIRES INTERVENTION WITH A COMBINATION OF PHARMACOLOGICAL AND BEHAVIORAL THERAPIES. THERE ARE IMPORTANT SEX DIFFERENCES IN HOW THE BRAIN RESPONDS TO STRESSORS. MOREOVER, ADVERSE EARLY LIFE EXPERIENCE, INTERACTING WITH ALLELES OF CERTAIN GENES, PRODUCES LASTING EFFECTS ON BRAIN AND BODY VIA EPIGENETIC MECHANISMS. WHILE PREVENTION IS KEY, THE PLASTICITY OF THE BRAIN GIVES HOPE FOR THERAPIES THAT UTILIZE BRAIN-BODY INTERACTIONS. POLICIES OF GOVERNMENT AND THE PRIVATE SECTOR ARE IMPORTANT TO PROMOTE HEALTH AND INCREASE "HEALTHSPAN." 2017 19 534 28 ASTROGLIA IN THE VULNERABILITY TO AND MAINTENANCE OF STRESS-MEDIATED NEUROPATHOLOGY AND DEPRESSION. SIGNIFICANT STRESS EXPOSURE AND PSYCHIATRIC DEPRESSION ARE ASSOCIATED WITH MORPHOLOGICAL, BIOCHEMICAL, AND PHYSIOLOGICAL DISTURBANCES OF ASTROCYTES IN SPECIFIC BRAIN REGIONS RELEVANT TO THE PATHOPHYSIOLOGY OF THOSE DISORDERS, SUGGESTING THAT ASTROCYTES ARE INVOLVED IN THE MECHANISMS UNDERLYING THE VULNERABILITY TO OR MAINTENANCE OF STRESS-RELATED NEUROPATHOLOGY AND DEPRESSION. TO UNDERSTAND THOSE MECHANISMS A VARIETY OF STUDIES HAVE PROBED THE EFFECT OF VARIOUS MODALITIES OF STRESS EXPOSURE ON THE METABOLISM, GENE EXPRESSION AND PLASTICITY OF ASTROCYTES. THESE STUDIES HAVE UNCOVERED THE PARTICIPATION OF VARIOUS CELLULAR PATHWAYS, SUCH AS THOSE FOR INTRACELLULAR CALCIUM REGULATION, NEUROIMMUNE RESPONSES, EXTRACELLULAR IONIC REGULATION, GAP JUNCTIONS-BASED CELLULAR COMMUNICATION, AND REGULATION OF NEUROTRANSMITTER AND GLIOTRANSMITTER RELEASE AND UPTAKE. MORE RECENTLY EPIGENETIC MODIFICATIONS RESULTING FROM EXPOSURE TO CHRONIC FORMS OF STRESS OR TO EARLY LIFE ADVERSITY HAVE BEEN SUGGESTED TO AFFECT NOT ONLY NEURONAL MECHANISMS BUT ALSO GENE EXPRESSION AND PHYSIOLOGY OF ASTROCYTES AND OTHER GLIAL CELLS. HOWEVER, MUCH REMAINS TO BE LEARNED TO UNDERSTAND THE SPECIFIC ROLE OF THOSE AND OTHER MODIFICATIONS IN THE ASTROGLIAL CONTRIBUTION TO THE VULNERABILITY TO AND MAINTENANCE OF STRESS-RELATED DISORDERS AND DEPRESSION, AND FOR LEVERAGING THAT KNOWLEDGE TO ACHIEVE MORE EFFECTIVE PSYCHIATRIC THERAPIES. 2022 20 2269 36 EPIGENETIC PROGRAMMING OF THE NEUROENDOCRINE STRESS RESPONSE BY ADULT LIFE STRESS. THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS IS CRITICALLY INVOLVED IN THE NEUROENDOCRINE REGULATION OF STRESS ADAPTATION, AND THE RESTORATION OF HOMEOSTASIS FOLLOWING STRESS EXPOSURE. DYSREGULATION OF THIS AXIS IS ASSOCIATED WITH STRESS-RELATED PATHOLOGIES LIKE MAJOR DEPRESSIVE DISORDER, POST-TRAUMATIC STRESS DISORDER, PANIC DISORDER AND CHRONIC ANXIETY. IT HAS LONG BEEN UNDERSTOOD THAT STRESS DURING EARLY LIFE CAN HAVE A SIGNIFICANT LASTING INFLUENCE ON THE DEVELOPMENT OF THE NEUROENDOCRINE SYSTEM AND ITS NEURAL REGULATORS, PARTIALLY BY MODIFYING EPIGENETIC REGULATION OF GENE EXPRESSION, WITH IMPLICATIONS FOR HEALTH AND WELL-BEING IN LATER LIFE. EVIDENCE IS ACCUMULATING THAT EPIGENETIC PLASTICITY ALSO EXTENDS TO ADULTHOOD, PROPOSING IT AS A MECHANISM BY WHICH PSYCHOLOGICAL TRAUMA LATER IN LIFE CAN LONG-LASTINGLY AFFECT HPA AXIS FUNCTION, BRAIN PLASTICITY, NEURONAL FUNCTION AND BEHAVIOURAL ADAPTATION TO NEUROPSYCHOLOGICAL STRESS. FURTHER CORROBORATING THIS CLAIM IS THE PHENOMENON THAT THESE EPIGENETIC CHANGES CORRELATE WITH THE BEHAVIOURAL CONSEQUENCES OF TRAUMA EXPOSURE. THEREBY, EPIGENETIC MODIFICATIONS PROVIDE A PUTATIVE MOLECULAR MECHANISM BY WHICH THE BEHAVIOURAL PHENOTYPE AND TRANSCRIPTIONAL/TRANSLATIONAL POTENTIAL OF GENES INVOLVED IN HPA AXIS REGULATION CAN CHANGE DRASTICALLY IN RESPONSE TO ENVIRONMENTAL CHALLENGES, AND APPEAR AN IMPORTANT TARGET FOR TREATMENT OF STRESS-RELATED DISORDERS. HOWEVER, IMPROVED INSIGHT IS REQUIRED TO INCREASE THEIR THERAPEUTIC (DRUG) POTENTIAL. HERE, WE PROVIDE AN OVERVIEW OF THE GROWING BODY OF LITERATURE DESCRIBING THE EPIGENETIC MODULATION OF THE (PRIMARILY NEUROENDOCRINE) STRESS RESPONSE AS A CONSEQUENCE OF ADULT LIFE STRESS AND INTERPRET THE IMPLICATIONS FOR, AND THE CHALLENGES INVOLVED IN APPLYING THIS KNOWLEDGE TO, THE IDENTIFICATION AND TREATMENT OF STRESS-RELATED PSYCHIATRIC DISORDERS. 2017