1 3708 99 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 2 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 3 4420 27 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 4 5828 26 STRESS, EPIGENETICS, AND ALCOHOLISM. ACUTE AND CHRONIC STRESSORS HAVE BEEN ASSOCIATED WITH ALTERATIONS IN MOOD AND INCREASED ANXIETY THAT MAY EVENTUALLY RESULT IN THE DEVELOPMENT OF STRESS-RELATED PSYCHIATRIC DISORDERS. STRESS AND ASSOCIATED DISORDERS, INCLUDING ANXIETY, ARE KEY FACTORS IN THE DEVELOPMENT OF ALCOHOLISM BECAUSE ALCOHOL CONSUMPTION CAN TEMPORARILY REDUCE THE DRINKER'S DYSPHORIA. ONE MOLECULE THAT MAY HELP MEDIATE THE RELATIONSHIP BETWEEN STRESS AND ALCOHOL CONSUMPTION IS BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF), A PROTEIN THAT REGULATES THE STRUCTURE AND FUNCTION OF THE SITES WHERE TWO NERVE CELLS INTERACT AND EXCHANGE NERVE SIGNALS (I.E., SYNAPSES) AND WHICH IS INVOLVED IN NUMEROUS PHYSIOLOGICAL PROCESSES. ABERRANT REGULATION OF BDNF SIGNALING AND ALTERATIONS IN SYNAPSE ACTIVITY (I.E., SYNAPTIC PLASTICITY) HAVE BEEN ASSOCIATED WITH THE PATHOPHYSIOLOGY OF STRESS-RELATED DISORDERS AND ALCOHOLISM. MECHANISMS THAT CONTRIBUTE TO THE REGULATION OF GENETIC INFORMATION WITHOUT MODIFICATION OF THE DNA SEQUENCE (I.E., EPIGENETIC MECHANISMS) MAY PLAY A ROLE IN THE COMPLEX CONTROL OF BDNF SIGNALING AND SYNAPTIC PLASTICITY-FOR EXAMPLE, BY MODIFYING THE STRUCTURE OF THE DNA-PROTEIN COMPLEXES (I.E., CHROMATIN) THAT MAKE UP THE CHROMOSOMES AND THEREBY MODULATING THE EXPRESSION OF CERTAIN GENES. STUDIES REGARDING THE EPIGENETIC CONTROL OF BDNF SIGNALING AND SYNAPTIC PLASTICITY PROVIDE A PROMISING DIRECTION TO UNDERSTAND THE MECHANISMS MEDIATING THE INTERACTION BETWEEN STRESS AND ALCOHOLISM. 2012 5 636 29 BIOLOGICAL SUBSTRATES OF ADDICTION. THIS REVIEW IS AN INTRODUCTION TO ADDICTION, THE REWARD CIRCUITRY, AND LABORATORY ADDICTION MODELS. ADDICTION IS A CHRONIC DISEASE HALLMARKED BY A STATE OF COMPULSIVE DRUG SEEKING THAT PERSISTS DESPITE NEGATIVE CONSEQUENCES. MOST OF THE ADVANCES IN ADDICTION RESEARCH HAVE CENTERED ON THE CANONICAL AND CONTEMPORARY DRUGS OF ABUSE; HOWEVER, ADDICTIONS TO OTHER ACTIVITIES AND STIMULI ALSO EXIST. SUBSTANCES OF ABUSE HAVE THE POTENTIAL TO INDUCE LONG-LASTING CHANGES IN THE BRAIN AT THE BEHAVIORAL, CIRCUIT, AND SYNAPTIC LEVELS. ADDICTION-RELATED BEHAVIORAL CHANGES INVOLVE INITIATION, ESCALATION, AND OBSESSION TO DRUG SEEKING AND MUCH OF THE CURRENT RESEARCH IS FOCUSED ON MAPPING THESE MANIFESTATIONS TO SPECIFIC NEURAL PATHWAYS. DRUG ABUSE IS WELL KNOWN TO RECRUIT COMPONENTS OF THE MESOLIMBIC DOPAMINE SYSTEM, INCLUDING THE NUCLEUS ACCUMBENS AND VENTRAL TEGMENTAL AREA. IN ADDITION, ALTERED FUNCTION OF A WIDE VARIETY OF BRAIN REGIONS IS TIGHTLY ASSOCIATED WITH SPECIFIC MANIFESTATIONS OF DRUG ABUSE. THESE REGIONS PERIPHERAL TO THE MESOLIMBIC PATHWAY LIKELY PLAY A ROLE IN SPECIFIC OBSERVED COMORBIDITIES AND ENDOPHENOTYPES THAT CAN FACILITATE, OR BE CAUSED BY, SUBSTANCE ABUSE. ALTERATIONS IN SYNAPTIC STRUCTURE, FUNCTION, AND CONNECTIVITY, AS WELL AS EPIGENETIC AND GENETIC MECHANISMS ARE THOUGHT TO UNDERLIE THE PATHOLOGIES OF ADDICTION. IN PRECLINICAL MODELS, THESE PERSISTENT CHANGES ARE STUDIED AT THE LEVELS OF MOLECULAR PHARMACOLOGY AND BIOCHEMISTRY, EX VIVO AND IN VIVO ELECTROPHYSIOLOGY, RADIOGRAPHY, AND BEHAVIOR. COORDINATING RESEARCH EFFORTS ACROSS THESE DISCIPLINES AND EXAMINING CELL TYPE- AND CIRCUIT-SPECIFIC PHENOMENA ARE CRUCIAL COMPONENTS FOR TRANSLATING PRECLINICAL FINDINGS TO VIABLE MEDICAL INTERVENTIONS THAT EFFECTIVELY TREAT ADDICTION AND RELATED DISORDERS. WIRES COGN SCI 2014, 5:151-171. DOI: 10.1002/WCS.1273 CONFLICT OF INTEREST: THE AUTHORS HAVE DECLARED NO CONFLICTS OF INTEREST FOR THIS ARTICLE. FOR FURTHER RESOURCES RELATED TO THIS ARTICLE, PLEASE VISIT THE WIRES WEBSITE. 2014 6 2292 23 EPIGENETIC REGULATION IN SUBSTANCE USE DISORDERS. SUBSTANCE USE DISORDER IS A CHRONIC CONDITION OF COMPULSIVE DRUG SEEKING AND USE THAT IS MEDIATED BY STABLE CHANGES IN CENTRAL REWARD PATHWAYS. REPEATED USE OF ABUSED DRUGS CAUSES PERSISTENT ALTERATIONS IN GENE EXPRESSION RESPONSIBLE FOR THE LONG-TERM BEHAVIORAL AND STRUCTURAL CHANGES. RECENTLY, IT HAS BEEN SUGGESTED THAT EPIGENETIC MECHANISMS ARE RESPONSIBLE IN PART FOR THESE DRUG-INDUCED CHANGES IN GENE EXPRESSION. ONE OF THE ALLURING ASPECTS OF EPIGENETIC REGULATION OF GENE EXPRESSION IS THAT EPIGENETIC MECHANISMS MAY PROVIDE TRANSIENT AND POTENTIALLY STABLE CONDITIONS THAT IN TURN MAY ULTIMATELY PARTICIPATE IN THE MOLECULAR MECHANISMS REQUIRED FOR NEURONAL CHANGES SUBSERVING LONG-LASTING CHANGES IN BEHAVIOR. THIS REVIEW DESCRIBES EPIGENETIC MECHANISMS OF GENE REGULATION AND THEN DISCUSSES THE EMERGING ROLE OF EPIGENETICS IN DRUG-INDUCED PLASTICITY AND BEHAVIOR. UNDERSTANDING THESE MECHANISMS THAT ESTABLISH AND MAINTAIN DRUG-DEPENDENT PLASTICITY CHANGES MAY LEAD TO DEEPER UNDERSTANDING OF SUBSTANCE USE DISORDERS AS WELL AS NOVEL APPROACHES TO TREATMENT. 2010 7 2386 28 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 8 2092 22 EPIGENETIC EFFECT OF CHRONIC STRESS ON DOPAMINE SIGNALING AND DEPRESSION. BECAUSE OF THE COMPLEX CAUSAL FACTORS LEADING TO DEPRESSION, EPIGENETICS IS OF CONSIDERABLE INTEREST FOR THE UNDERSTANDING EFFECT OF STRESS IN DEPRESSION. DOPAMINE IS A KEY NEUROTRANSMITTER IMPORTANT IN MANY PHYSIOLOGICAL FUNCTIONS, INCLUDING MOTOR CONTROL, MOOD, AND THE REWARD PATHWAY. THESE FACTORS LEAD MANY DRUGS TO TARGET DOPAMINE RECEPTORS IN TREATING DEPRESSIVE DISORDERS. IN THIS REVIEW, WE TRY TO PORTRAY HOW CHRONIC STRESS AS AN EPIGENETIC FACTOR CHANGES THE GENE REGULATION PATTERN BY INTERRUPTING DOPAMINE SIGNALING MECHANISM. 2013 9 2596 26 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 10 534 25 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 11 678 27 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 12 4642 40 NEURONAL PLASTICITY: A LINK BETWEEN STRESS AND MOOD DISORDERS. ALTHOUGH STRESS REPRESENTS THE MAJOR ENVIRONMENTAL ELEMENT OF SUSCEPTIBILITY FOR MOOD DISORDERS, THE RELATIONSHIP BETWEEN STRESS AND DISEASE REMAINS TO BE FULLY ESTABLISHED. IN THE PRESENT ARTICLE WE REVIEW THE EVIDENCE IN SUPPORT FOR A ROLE OF NEURONAL PLASTICITY, AND IN PARTICULAR OF NEUROTROPHIC FACTORS. EVEN THOUGH DECREASED LEVELS OF NOREPINEPHRINE AND SEROTONIN MAY UNDERLIE DEPRESSIVE SYMPTOMS, COMPELLING EVIDENCE NOW SUGGESTS THAT MOOD DISORDERS ARE CHARACTERIZED BY REDUCED NEURONAL PLASTICITY, WHICH CAN BE BROUGHT ABOUT BY EXPOSURE TO STRESS AT DIFFERENT STAGES OF LIFE. INDEED THE EXPRESSION OF NEUROTROPHIC MOLECULES, SUCH AS THE NEUROTROPHIN BDNF, IS REDUCED IN DEPRESSED SUBJECTS AS WELL AS IN EXPERIMENTAL ANIMALS EXPOSED TO ADVERSE EXPERIENCE AT EARLY STAGES OF LIFE OR AT ADULTHOOD. THESE CHANGES SHOW AN ANATOMICAL SPECIFICITY AND MIGHT BE SUSTAINED BY EPIGENETIC MECHANISMS. PHARMACOLOGICAL INTERVENTION MAY NORMALIZE SUCH DEFECTS AND IMPROVE NEURONAL FUNCTION THROUGH THE MODULATION OF THE SAME FACTORS THAT ARE DEFECTIVE IN DEPRESSION. SEVERAL STUDIES HAVE DEMONSTRATED THAT CHRONIC, BUT NOT ACUTE, ANTIDEPRESSANT TREATMENT INCREASES THE EXPRESSION OF BDNF AND MAY ENHANCE ITS LOCALIZATION AT SYNAPTIC LEVEL. ANTIDEPRESSANT TREATMENT CAN NORMALIZE DEFICITS IN NEUROTROPHIN EXPRESSION PRODUCED BY CHRONIC STRESS PARADIGMS, BUT MAY ALSO ALTER THE MODULATION OF BDNF UNDER ACUTE STRESSFUL CONDITIONS. IN SUMMARY, THERE IS GOOD AGREEMENT IN CONSIDERING NEURONAL PLASTICITY, AND THE EXPRESSION OF KEY PROTEINS SUCH AS THE NEUROTROPHIN BDNF, AS A CENTRAL PLAYER FOR THE EFFECTS OF STRESS ON BRAIN FUNCTION AND ITS IMPLICATION FOR PSYCHOPATHOLOGY. ACCORDINGLY, EFFECTIVE TREATMENTS SHOULD NOT LIMIT THEIR EFFECTS TO THE CONTROL OF NEUROTRANSMITTER AND HORMONAL DYSFUNCTIONS, BUT SHOULD BE ABLE TO NORMALIZE DEFECTIVE MECHANISMS THAT SUSTAIN THE IMPAIRMENT OF NEURONAL PLASTICITY. 2009 13 584 36 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 14 2598 22 EPIGENETICS OF THE DEPRESSED BRAIN: ROLE OF HISTONE ACETYLATION AND METHYLATION. MAJOR DEPRESSIVE DISORDER IS A CHRONIC, REMITTING SYNDROME INVOLVING WIDELY DISTRIBUTED CIRCUITS IN THE BRAIN. STABLE ALTERATIONS IN GENE EXPRESSION THAT CONTRIBUTE TO STRUCTURAL AND FUNCTIONAL CHANGES IN MULTIPLE BRAIN REGIONS ARE IMPLICATED IN THE HETEROGENEITY AND PATHOGENESIS OF THE ILLNESS. EPIGENETIC EVENTS THAT ALTER CHROMATIN STRUCTURE TO REGULATE PROGRAMS OF GENE EXPRESSION HAVE BEEN ASSOCIATED WITH DEPRESSION-RELATED BEHAVIOR, ANTIDEPRESSANT ACTION, AND RESISTANCE TO DEPRESSION OR 'RESILIENCE' IN ANIMAL MODELS, WITH INCREASING EVIDENCE FOR SIMILAR MECHANISMS OCCURRING IN POSTMORTEM BRAINS OF DEPRESSED HUMANS. IN THIS REVIEW, WE DISCUSS RECENT ADVANCES IN OUR UNDERSTANDING OF EPIGENETIC CONTRIBUTIONS TO DEPRESSION, IN PARTICULAR THE ROLE OF HISTONE ACETYLATION AND METHYLATION, WHICH ARE REVEALING NOVEL MECHANISTIC INSIGHT INTO THE SYNDROME THAT MAY AID IN THE DEVELOPMENT OF NOVEL TARGETS FOR DEPRESSION TREATMENT. 2013 15 6174 41 THE HIPPOCAMPUS, NEUROTROPHIC FACTORS AND DEPRESSION: POSSIBLE IMPLICATIONS FOR THE PHARMACOTHERAPY OF DEPRESSION. DEPRESSION IS A PREVALENT, HIGHLY DEBILITATING MENTAL DISORDER AFFECTING UP TO 15% OF THE POPULATION AT LEAST ONCE IN THEIR LIFETIME, WITH HUGE COSTS FOR SOCIETY. NEUROBIOLOGICAL MECHANISMS OF DEPRESSION ARE STILL NOT WELL KNOWN, ALTHOUGH THERE IS CONSENSUS ABOUT INTERPLAY BETWEEN GENETIC AND ENVIRONMENTAL FACTORS. ANTIDEPRESSANT MEDICATIONS ARE FREQUENTLY USED IN DEPRESSION, BUT AT LEAST 50% OF PATIENTS ARE POOR RESPONDERS, EVEN TO MORE RECENTLY DISCOVERED MEDICATIONS. FURTHERMORE, CLINICAL RESPONSE ONLY OCCURS FOLLOWING WEEKS TO MONTHS OF TREATMENT AND ONLY CHRONIC TREATMENT IS EFFECTIVE, SUGGESTING THAT ACTIONS BEYOND THE RAPIDLY OCCURRING EFFECT OF ENHANCING MONOAMINERGIC SYSTEMS, SUCH AS ADAPTATION OF THESE SYSTEMS, ARE RESPONSIBLE FOR THE EFFECTS OF ANTIDEPRESSANTS. RECENT STUDIES INDICATE THAT AN IMPAIRMENT OF SYNAPTIC PLASTICITY (NEUROGENESIS, AXON BRANCHING, DENDRITOGENESIS AND SYNAPTOGENESIS) IN SPECIFIC AREAS OF THE CNS, PARTICULARLY THE HIPPOCAMPUS, MAY BE A CORE FACTOR IN THE PATHOPHYSIOLOGY OF DEPRESSION. THE ABNORMAL NEURAL PLASTICITY MAY BE RELATED TO ALTERATIONS IN THE LEVELS OF NEUROTROPHIC FACTORS, NAMELY BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF), WHICH PLAY A CENTRAL ROLE IN PLASTICITY. AS BDNF IS REPRESSED BY STRESS, EPIGENETIC REGULATION OF THE BDNF GENE MAY PLAY AN IMPORTANT ROLE IN DEPRESSION. THE HIPPOCAMPUS IS SMALLER IN DEPRESSED PATIENTS, ALTHOUGH IT IS UNCLEAR WHETHER SMALLER SIZE IS A CONSEQUENCE OF DEPRESSION OR A PRE-EXISTING, VULNERABILITY MARKER FOR DEPRESSION. ENVIRONMENTAL STRESSORS TRIGGERING ACTIVATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS CAUSE THE BRAIN TO BE EXPOSED TO CORTICOSTEROIDS, AFFECTING NEUROBEHAVIOURAL FUNCTIONS WITH A STRONG DOWNREGULATION OF HIPPOCAMPAL NEUROGENESIS, AND ARE A MAJOR RISK FACTOR FOR DEPRESSION. ANTIDEPRESSANT TREATMENT INCREASES BDNF LEVELS, STIMULATES NEUROGENESIS AND REVERSES THE INHIBITORY EFFECTS OF STRESS, BUT THIS EFFECT IS EVIDENT ONLY AFTER 3-4 WEEKS OF ADMINISTRATION, THE TIME COURSE FOR MATURATION OF NEW NEURONS. THE ABLATION OF HIPPOCAMPAL NEUROGENESIS BLOCKS THE BEHAVIOURAL EFFECTS OF ANTIDEPRESSANTS IN ANIMAL MODELS. THE ABOVE FINDINGS SUGGEST NEW POSSIBLE TARGETS FOR THE PHARMACOTHERAPY OF DEPRESSION SUCH AS NEUROTROPHIC FACTORS, THEIR RECEPTORS AND RELATED INTRACELLULAR SIGNALLING CASCADES; AGENTS COUNTERACTING THE EFFECTS OF STRESS ON HIPPOCAMPAL NEUROGENESIS (INCLUDING ANTAGONISTS OF CORTICOSTEROIDS, INFLAMMATORY CYTOKINES AND THEIR RECEPTORS); AND AGENTS FACILITATING THE ACTIVATION OF GENE EXPRESSION AND INCREASING THE TRANSCRIPTION OF NEUROTROPHINS IN THE BRAIN. 2011 16 5876 21 SYNAPTIC PLASTICITY AND PAIN AVERSION. NEGATIVE AFFECTIVE EMOTIONS ARE DEFINED AS THE CONCEPTUAL FEATURE OF PAIN. A NUMBER OF CLINICAL AND ANIMAL STUDIES HAVE INDICATED THAT THE LIMBIC SYSTEM INCLUDING THE ANTERIOR CINGULATE CORTEX (ACC) AND AMYGDALA PLAYS A CRITICAL ROLE IN THE PROCESSING OF AFFECTIVE COMPONENTS OF PAIN. GLUTAMATERGIC TRANSMISSION PLAYS AN IMPORTANT ROLE IN THE PROCESSING OF AFFECTIVE ASPECTS OF PAIN. LONG-TERM CHANGES ON GLUTAMATERGIC SYNAPSES CONTRIBUTE TO THE EXPRESSION OF AVERSION BEHAVIOR INDUCED BY PAIN. IN THIS ARTICLE, THE NEUROCIRCUITS INVOLVED IN THE PROCESSING OF AFFECTIVE ASPECTS OF PAIN, THE GLUTAMATERGIC SYNAPTIC PLASTICITY IN THESE BRAIN REGIONS, AND THE EPIGENETIC MECHANISMS UNDERLYING PAIN-RELATED SYNAPTIC PLASTICITY WILL BE REVIEWED AND DISCUSSED. NEW DISCOVERIES REGARDING THE INTERACTION BETWEEN THE SYNAPTIC PLASTICITY AND AFFECTIVE COMPONENTS OF PAIN MAY ADVANCE OUR UNDERSTANDING ON THE PAIN MECHANISM, AND LEAD TO NEW STRATEGIES FOR PAIN TREATMENT. 2011 17 2520 24 EPIGENETICS AND THE GLUCOCORTICOID RECEPTOR: A REVIEW OF THE IMPLICATIONS IN DEPRESSION. DEPRESSION IS A SERIOUS PSYCHIATRIC DISORDER THAT EFFECTS AT LEAST 350 MILLION PEOPLE WORLDWIDE TODAY. DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS (HPAA) IS A ROBUST FINDING IN THE PATHOPHYSIOLOGY OF DEPRESSION. THIS DYSREGULATION IS HYPOTHESIZED TO RESULT FROM ALTERED CENTRAL GLUCOCORTICOID RECEPTOR (GR) LEVELS AND/OR FUNCTION AS A CONSEQUENCE OF CHRONIC GLUCOCORTICOID (GC) RELEASE, LEADING TO RECEPTOR RESISTANCE. PIVOTAL ANIMAL AND HUMAN RESEARCH TO DATE HAS IDENTIFIED THAT EARLY LIFE EXPOSURE TO PROLONGED LEVELS OF GCS, STRESS AND/OR DEPRESSION, CAN INDUCE EPIGENETIC MODIFICATIONS AT KEY REGIONS ON THE GR GENE THAT LEAD TO ALTERATIONS IN GR EXPRESSION AND FUNCTION. EPIGENETICS PROVIDES AN ATTRACTIVE MECHANISM TO EXPLAIN HOW ONES' GENES AND ENVIRONMENT CAN INTERACT TO PRODUCE DIFFERENT DISEASE PHENOTYPES. THIS REVIEW AIMS TO COMPILE THE INFORMATION THAT HAS BEEN COLLECTED TO DATE AND TO IDENTIFY KEY AREAS FOR FURTHER INVESTIGATION. 2016 18 677 26 BRAIN CIRCUITS AT RISK IN PSYCHIATRIC DISEASES AND PHARMACOLOGICAL PATHWAYS. THE MULTIPLE BRAIN CIRCUITS INVOLVED IN PSYCHIATRIC DISEASES MAY APPEAR DAUNTING, BUT WE PREFER TO CONCENTRATE ON A SELECT FEW, WITH A PARTICULAR SENSITIVITY TO STRESS AND NEURODEVELOPMENTAL ISSUES, WITH A CLEAR PHARMACOTHERAPY. THIS REVIEW IS STRUCTURED AROUND 1. THE KEY CIRCUITS, THEIR ROLE IN HEALTH AND DISEASE, AND THE NEUROTRANSMITTERS MAINTAINING THEM, 2. THE INFLUENCE OF UPBRINGING, STRESS, CHRONOBIOLOGY, INFLAMMATION AND INFECTION, 3. THE GENETIC AND EPIGENETIC INFLUENCE ON THESE CIRCUITS, PARTICULARLY REGARDING COPY NUMBER VARIANTS AND NEURONAL PLASTICITY, 4. THE USE AND ABUSE OF PHARMACOLOGICAL AGENTS WITH THE PARTICULAR RISKS OF STRESS AND CHRONOBIOLOGY AT CRITICAL PERIODS. A MAJOR EMPHASIS IS PLACED ON THE LINKS BETWEEN HIPPOCAMPUS, PREFRONTAL CORTEX AND AMYGDALA/PERIAQUEDUCTAL GREY WHICH CONTROL SPECIFIC ASPECTS OF COGNITION, MOOD, PAIN AND EVEN VIOLENCE. SOME OF THE RESEARCH FINDINGS WERE FROM THE INNOVATIVE MEDICINE INITIATIVE (IMI) NEWMEDS, A 22MEURO ACADEMIC/INDUSTRIAL CONSORTIUM ON THE BRAIN CIRCUITS CRITICAL FOR PSYCHIATRIC DISEASE. 2021 19 2235 23 EPIGENETIC MODIFICATIONS, ALCOHOLIC BRAIN AND POTENTIAL DRUG TARGETS. ACUTE AND CHRONIC ALCOHOL EXPOSURE EVIDENTLY INFLUENCES EPIGENETIC CHANGES, BOTH TRANSIENTLY AND PERMANENTLY, AND THESE CHANGES IN TURN INFLUENCE A VARIETY OF CELLS AND ORGAN SYSTEMS THROUGHOUT THE BODY. MANY OF THE ALCOHOL-INDUCED EPIGENETIC MODIFICATIONS CAN CONTRIBUTE TO CELLULAR ADAPTATIONS THAT ULTIMATELY LEAD TO BEHAVIORAL TOLERANCE AND ALCOHOL DEPENDENCE. THE PERSISTENCE OF BEHAVIORAL CHANGES DEMONSTRATES THAT LONG-LASTING CHANGES IN GENE EXPRESSION, WITHIN PARTICULAR REGIONS OF THE BRAIN, MAY CONTRIBUTE IMPORTANTLY TO THE ADDICTION PHENOTYPE. THE RESEARCH ACTIVITIES OVER THE PAST YEARS HAVE DEMONSTRATED A CRUCIAL ROLE OF EPIGENETIC MECHANISMS IN CAUSING LONG LASTING AND TRANSIENT CHANGES IN THE EXPRESSION OF SEVERAL GENES IN DIVERSE TISSUES, INCLUDING BRAIN. THIS HAS STIMULATED RECENT RESEARCH WORK THAT IS AIMED AT CHARACTERIZING THE INFLUENCE OF EPIGENETIC REGULATORY EVENTS IN MEDIATING THE LONG LASTING AND TRANSIENT EFFECTS OF ALCOHOL ABUSE ON THE BRAIN IN HUMANS AND ANIMAL MODELS OF ALCOHOL ADDICTION. IN THIS STUDY, WE UPDATE OUR CURRENT UNDERSTANDING OF THE IMPACT OF ALCOHOL EXPOSURE ON EPIGENETIC MECHANISMS IN THE BRAIN AND REFURBISH THE KNOWLEDGE OF EPIGENETICS IN THE DIRECTION OF NEW DRUGS DEVELOPMENT. 2016 20 291 31 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