1 4758 169 NOVEL TREATMENT STRATEGIES TARGETING MYELIN AND OLIGODENDROCYTE DYSFUNCTION IN SCHIZOPHRENIA. OLIGODENDROCYTES ARE THE GLIAL CELLS RESPONSIBLE FOR THE FORMATION OF THE MYELIN SHEATH AROUND AXONS. DURING NEURODEVELOPMENT, OLIGODENDROCYTES UNDERGO MATURATION AND DIFFERENTIATION, AND LATER REMYELINATION IN ADULTHOOD. ABNORMALITIES IN THESE PROCESSES HAVE BEEN ASSOCIATED WITH BEHAVIORAL AND COGNITIVE DYSFUNCTIONS AND THE DEVELOPMENT OF VARIOUS MENTAL ILLNESSES LIKE SCHIZOPHRENIA. SEVERAL STUDIES HAVE IMPLICATED OLIGODENDROCYTE DYSFUNCTION AND MYELIN ABNORMALITIES IN THE DISORDER, TOGETHER WITH ALTERED EXPRESSION OF MYELIN-RELATED GENES SUCH AS OLIG2, CNP, AND NRG1. HOWEVER, THE MOLECULAR MECHANISMS SUBJACENT OF THESE ALTERATIONS REMAIN ELUSIVE. SCHIZOPHRENIA IS A SEVERE, CHRONIC PSYCHIATRIC DISORDER AFFECTING MORE THAN 23 MILLION INDIVIDUALS WORLDWIDE AND ITS SYMPTOMS USUALLY APPEAR AT THE BEGINNING OF ADULTHOOD. CURRENTLY, THE MAJOR THERAPEUTIC STRATEGY FOR SCHIZOPHRENIA RELIES ON THE USE OF ANTIPSYCHOTICS. DESPITE THEIR WIDESPREAD USE, THE EFFECTS OF ANTIPSYCHOTICS ON GLIAL CELLS, ESPECIALLY OLIGODENDROCYTES, REMAIN UNCLEAR. THUS, IN THIS REVIEW WE HIGHLIGHT THE CURRENT KNOWLEDGE REGARDING OLIGODENDROCYTE DYSFUNCTION IN SCHIZOPHRENIA, COMPILING DATA FROM (EPI)GENETIC STUDIES AND UP-TO-DATE MODELS TO INVESTIGATE THE ROLE OF OLIGODENDROCYTES IN THE DISORDER. IN ADDITION, WE EXAMINED POTENTIAL TARGETS CURRENTLY INVESTIGATED FOR THE IMPROVEMENT OF SCHIZOPHRENIA SYMPTOMS. RESEARCH IN THIS AREA HAS BEEN INVESTIGATING POTENTIAL BENEFICIAL COMPOUNDS, INCLUDING THE D-AMINO ACIDS D-ASPARTATE AND D-SERINE, THAT ACT AS NMDA RECEPTOR AGONISTS, MODULATING THE GLUTAMATERGIC SIGNALING; THE ANTIOXIDANT N-ACETYLCYSTEINE, A PRECURSOR IN THE SYNTHESIS OF GLUTATHIONE, PROTECTING AGAINST THE REDOX IMBALANCE; AS WELL AS LITHIUM, AN INHIBITOR OF GLYCOGEN SYNTHASE KINASE 3BETA (GSK3BETA) SIGNALING, CONTRIBUTING TO OLIGODENDROCYTE SURVIVAL AND FUNCTIONING. IN CONCLUSION, THERE IS STRONG EVIDENCE LINKING OLIGODENDROCYTE DYSFUNCTION TO THE DEVELOPMENT OF SCHIZOPHRENIA. HENCE, A BETTER UNDERSTANDING OF OLIGODENDROCYTE DIFFERENTIATION, AS WELL AS THE EFFECTS OF ANTIPSYCHOTIC MEDICATION IN THESE CELLS, COULD HAVE POTENTIAL IMPLICATIONS FOR UNDERSTANDING THE DEVELOPMENT OF SCHIZOPHRENIA AND FINDING NEW TARGETS FOR DRUG DEVELOPMENT. 2020 2 1179 36 CONVERGENCE AND DIVERGENCE IN THE ETIOLOGY OF MYELIN IMPAIRMENT IN PSYCHIATRIC DISORDERS AND DRUG ADDICTION. IMPAIRMENT OF OLIGODENDROGLIA (OL)-DEPENDENT MYELINATION IN THE CENTRAL NERVOUS SYSTEM (CNS) IS A REMARKABLE PARALLEL RECENTLY IDENTIFIED IN MAJOR PSYCHIATRIC DISORDERS AND CHRONIC DRUG ABUSE. NEUROIMAGING AND NEUROPATHOLOGICAL STUDIES REVEALED MYELIN DEFECTS AND MICROARRAY-PROFILING ANALYSIS DEMONSTRATED ABERRANT EXPRESSION OF MYELIN-RELATED GENES IN SCHIZOPHRENIA (SZ), BIPOLAR DISORDER (BD), MAJOR DEPRESSIVE DISORDER (MDD) AND COCAINE ADDICTION. HOWEVER, THE ETIOLOGY UNDERLYING MYELIN IMPAIRMENT IN THESE CLINICALLY DISTINCT SUBJECTS REMAINS ELUSIVE. THIS ARTICLE REVIEWS MYELIN IMPAIRMENT IN LINE WITH DOPAMINERGIC DYSFUNCTION, A PRIME NEUROPATHOPHYSIOLOGICAL TRAIT SHARED IN PSYCHIATRIC DISORDERS AND DRUG ABUSE, AS WELL AS THE GENETIC AND EPIGENETIC ALTERATIONS ASSOCIATED WITH THESE DISEASES. THE CURRENT FINDINGS SUPPORT THE HYPOTHESIS THAT ABERRANT DOPAMINE (DA) ACTION ON OLS IS A COMMON PATHOLOGIC MECHANISM FOR MYELIN IMPAIRMENT IN THE AFOREMENTIONED MENTAL MORBIDITIES, WHEREAS INHERITED GENETIC VARIATIONS THAT SPECIFICALLY AFFECT OL DEVELOPMENT AND MYELINOGENESIS MAY FURTHER INCREASE MYELIN VULNERABILITY IN PSYCHIATRIC DISORDERS. IMPORTANTLY, OL DEFECT IS NOT ONLY A PATHOLOGICAL CONSEQUENCE BUT ALSO A CAUSATIVE FACTOR FOR DOPAMINERGIC DYSFUNCTION. HENCE, MYELIN IMPAIRMENT IS A KEY FACTOR IN THE PATHOGENIC LOOP OF PSYCHIATRIC DISEASES AND DRUG ADDICTION. 2008 3 4277 43 MICROGLIA SEQUELAE: BRAIN SIGNATURE OF INNATE IMMUNITY IN SCHIZOPHRENIA. SCHIZOPHRENIA IS A PSYCHIATRIC DISORDER WITH SIGNIFICANT IMPACT ON INDIVIDUALS AND SOCIETY. THE CURRENT PHARMACOLOGIC TREATMENT, WHICH PRINCIPALLY ALLEVIATES PSYCHOSIS, IS FOCUSED ON NEUROTRANSMITTERS MODULATION, RELYING ON DRUGS WITH SEVERE SIDE EFFECTS AND INEFFECTIVENESS IN A SIGNIFICANT PERCENTAGE OF CASES. THEREFORE, AND DUE TO DIFFICULTIES INHERENT TO DIAGNOSIS AND TREATMENT, IT IS VITAL TO REASSESS ALTERNATIVE CELLULAR AND MOLECULAR DRUG TARGETS. DISTINCT RISK FACTORS - GENETIC, DEVELOPMENTAL, EPIGENETIC, AND ENVIRONMENTAL - HAVE BEEN ASSOCIATED WITH DISEASE ONSET AND PROGRESSION, GIVING RISE TO THE PROPOSAL OF DIFFERENT PATHOPHYSIOLOGICAL MECHANISMS AND PUTATIVE PHARMACOLOGICAL TARGETS. IMMUNITY IS INVOLVED AND, PARTICULARLY MICROGLIA - INNATE IMMUNE CELLS OF THE CENTRAL NERVOUS SYSTEM, CRITICALLY INVOLVED IN BRAIN DEVELOPMENT - HAVE CAPTURED ATTENTION AS CELLULAR PLAYERS. MICROGLIA UNDERGO MARKED MORPHOLOGIC AND FUNCTIONAL ALTERATIONS IN THE HUMAN DISEASE, AS WELL AS IN ANIMAL MODELS OF SCHIZOPHRENIA, AS REPORTED IN SEVERAL ORIGINAL PAPERS. WE CLUSTER THE MAIN FINDINGS OF CLINICAL STUDIES BY GROUPS OF PATIENTS: (1) AT ULTRA-HIGH RISK OF PSYCHOSIS, (2) WITH A FIRST EPISODE OF PSYCHOSIS OR RECENT-ONSET SCHIZOPHRENIA, AND (3) WITH CHRONIC SCHIZOPHRENIA; IN TRANSLATIONAL STUDIES, WE HIGHLIGHT THE TIME WINDOW OF APPEARANCE OF PARTICULAR MICROGLIA ALTERATIONS IN THE MOST WELL STUDIED ANIMAL MODEL IN THE FIELD (MATERNAL IMMUNE ACTIVATION). THE ORGANIZATION OF CLINICAL AND TRANSLATIONAL FINDINGS BASED ON SCHIZOPHRENIA-ASSOCIATED MICROGLIA CHANGES IN DIFFERENT PHASES OF THE DISEASE COURSE MAY HELP DEFINING A TEMPORAL PATTERN OF MICROGLIA CHANGES AND MAY DRIVE THE DESIGN OF NOVEL THERAPEUTIC STRATEGIES. 2022 4 5369 27 RECENT ADVANCES IN UNDERSTANDING NEUROPATHIC PAIN: GLIA, SEX DIFFERENCES, AND EPIGENETICS. NEUROPATHIC PAIN RESULTS FROM DISEASES OR TRAUMA AFFECTING THE NERVOUS SYSTEM. THIS PAIN CAN BE DEVASTATING AND IS POORLY CONTROLLED. THE PATHOPHYSIOLOGY IS COMPLEX, AND IT IS ESSENTIAL TO UNDERSTAND THE UNDERLYING MECHANISMS IN ORDER TO IDENTIFY THE RELEVANT TARGETS FOR THERAPEUTIC INTERVENTION. IN THIS ARTICLE, WE FOCUS ON THE RECENT RESEARCH INVESTIGATING NEURO-IMMUNE COMMUNICATION AND EPIGENETIC PROCESSES, WHICH GAIN PARTICULAR ATTENTION IN THE CONTEXT OF NEUROPATHIC PAIN. SPECIFICALLY, WE ANALYZE THE ROLE OF GLIAL CELLS, INCLUDING MICROGLIA, ASTROCYTES, AND OLIGODENDROCYTES, IN THE MODULATION OF THE CENTRAL NERVOUS SYSTEM INFLAMMATION TRIGGERED BY NEUROPATHY. CONSIDERING EPIGENETICS, WE ADDRESS DNA METHYLATION, HISTONE MODIFICATIONS, AND THE NON-CODING RNAS IN THE REGULATION OF ION CHANNELS, G-PROTEIN-COUPLED RECEPTORS, AND TRANSMITTERS FOLLOWING NEURONAL DAMAGE. THE GOAL WAS NOT ONLY TO HIGHLIGHT THE EMERGING CONCEPTS BUT ALSO TO DISCUSS CONTROVERSIES, METHODOLOGICAL COMPLICATIONS, AND INTRIGUING OPINIONS. 2016 5 4470 50 MOLECULAR NEUROPATHOLOGY OF ASTROCYTES AND OLIGODENDROCYTES IN ALCOHOL USE DISORDERS. POSTMORTEM STUDIES REVEAL STRUCTURAL AND MOLECULAR ALTERATIONS OF ASTROCYTES AND OLIGODENDROCYTES IN BOTH THE GRAY AND WHITE MATTER (GM AND WM) OF THE PREFRONTAL CORTEX (PFC) IN HUMAN SUBJECTS WITH CHRONIC ALCOHOL ABUSE OR DEPENDENCE. THESE GLIAL CELLULAR CHANGES APPEAR TO PARALLEL AND MAY LARGELY EXPLAIN STRUCTURAL AND FUNCTIONAL ALTERATIONS DETECTED USING NEUROIMAGING TECHNIQUES IN SUBJECTS WITH ALCOHOL USE DISORDERS (AUDS). MOREOVER, DUE TO THE CRUCIAL ROLES OF ASTROCYTES AND OLIGODENDROCYTES IN NEUROTRANSMISSION AND SIGNAL CONDUCTION, THESE CELLS ARE VERY LIKELY MAJOR PLAYERS IN THE MOLECULAR MECHANISMS UNDERPINNING ALCOHOLISM-RELATED CONNECTIVITY DISTURBANCES BETWEEN THE PFC AND RELEVANT INTERCONNECTING BRAIN REGIONS. THE GLIA-MEDIATED ETIOLOGY OF ALCOHOL-RELATED BRAIN DAMAGE IS LIKELY MULTIFACTORIAL SINCE METABOLIC, HORMONAL, HEPATIC AND HEMODYNAMIC FACTORS AS WELL AS DIRECT ACTIONS OF ETHANOL OR ITS METABOLITES HAVE THE POTENTIAL TO DISRUPT DISTINCT ASPECTS OF GLIAL NEUROBIOLOGY. STUDIES IN ANIMAL MODELS OF ALCOHOLISM AND POSTMORTEM HUMAN BRAINS HAVE IDENTIFIED ASTROCYTE MARKERS ALTERED IN RESPONSE TO SIGNIFICANT EXPOSURES TO ETHANOL OR DURING ALCOHOL WITHDRAWAL, SUCH AS GAP-JUNCTION PROTEINS, GLUTAMATE TRANSPORTERS OR ENZYMES RELATED TO GLUTAMATE AND GAMMA-AMINOBUTYRIC ACID (GABA) METABOLISM. CHANGES IN THESE PROTEINS AND THEIR REGULATORY PATHWAYS WOULD NOT ONLY CAUSE GM NEURONAL DYSFUNCTION, BUT ALSO DISTURBANCES IN THE ABILITY OF WM AXONS TO CONVEY IMPULSES. IN ADDITION, ALCOHOLISM ALTERS THE EXPRESSION OF ASTROCYTE AND MYELIN PROTEINS AND OF OLIGODENDROCYTE TRANSCRIPTION FACTORS IMPORTANT FOR THE MAINTENANCE AND PLASTICITY OF MYELIN SHEATHS IN WM AND GM. THESE CHANGES ARE CONCOMITANT WITH EPIGENETIC DNA AND HISTONE MODIFICATIONS AS WELL AS ALTERATIONS IN REGULATORY MICRORNAS (MIRNAS) THAT LIKELY CAUSE PROFOUND DISTURBANCES OF GENE EXPRESSION AND PROTEIN TRANSLATION. KNOWLEDGE IS ALSO AVAILABLE ABOUT INTERACTIONS BETWEEN ASTROCYTES AND OLIGODENDROCYTES NOT ONLY AT THE NODES OF RANVIER (NR), BUT ALSO IN GAP JUNCTION-BASED ASTROCYTE-OLIGODENDROCYTE CONTACTS AND OTHER FORMS OF CELL-TO-CELL COMMUNICATION NOW UNDERSTOOD TO BE CRITICAL FOR THE MAINTENANCE AND FORMATION OF MYELIN. CLOSE INTERACTIONS BETWEEN ASTROCYTES AND OLIGODENDROCYTES ALSO SUGGEST THAT THERAPIES FOR ALCOHOLISM BASED ON A SPECIFIC GLIAL CELL TYPE PATHOLOGY WILL REQUIRE A BETTER UNDERSTANDING OF MOLECULAR INTERACTIONS BETWEEN DIFFERENT CELL TYPES, AS WELL AS CONSIDERING THE POSSIBILITY OF USING COMBINED MOLECULAR APPROACHES FOR MORE EFFECTIVE THERAPIES. 2018 6 4651 45 NEUROPROGRESSION IN SCHIZOPHRENIA: PATHWAYS UNDERPINNING CLINICAL STAGING AND THERAPEUTIC COROLLARIES. OBJECTIVE: WHILST DOPAMINERGIC DYSFUNCTION REMAINS A NECESSARY COMPONENT INVOLVED IN THE PATHOGENESIS OF SCHIZOPHRENIA, OUR CURRENT PHARMACOLOGICAL ARMOURY OF DOPAMINE ANTAGONISTS DOES LITTLE TO CONTROL THE NEGATIVE SYMPTOMS OF SCHIZOPHRENIA. THIS SUGGESTS OTHER PATHOLOGICAL PROCESSES MUST BE IMPLICATED. THIS PAPER AIMS TO ELABORATE ON SUCH THEORIES. METHODS: DATA FOR THIS REVIEW WERE SOURCED FROM THE ELECTRONIC DATABASE PUBMED, AND WAS NOT LIMITED BY LANGUAGE OR DATE OF PUBLICATION. RESULTS: IT HAS BEEN SUGGESTED THAT MULTIPLE 'HITS' MAY BE REQUIRED TO UNVEIL THE CLINICAL SYNDROME IN SUSCEPTIBLE INDIVIDUALS. SUCH HITS POTENTIALLY FIRST OCCUR IN UTERO, LEADING TO NEURONAL DISRUPTION, EPIGENETIC CHANGES AND THE ESTABLISHMENT OF AN ABNORMAL INFLAMMATORY RESPONSE. THE DEVELOPMENT OF SCHIZOPHRENIA MAY THEREFORE POTENTIALLY BE VIEWED AS A NEUROPROGRESSIVE RESPONSE TO THESE EARLY STRESSORS, DRIVEN ON BY CHANGES IN TRYPTOPHAN CATABOLITE (TRYCAT) METABOLISM, REACTIVE OXYGEN SPECIES HANDLING AND N-METHYL D-ASPARTATE (NMDA) CIRCUITRY. GIVEN THE POTENTIAL FOR SUCH PROGRESSION OVER TIME, IT IS PRUDENT TO EXPLORE THE NEW TREATMENT STRATEGIES WHICH MAY BE IMPLEMENTED BEFORE SUCH CHANGES BECOME ESTABLISHED. CONCLUSIONS: OUTSIDE OF THE DOPAMINERGIC MODEL, THE POTENTIAL PATHOGENESIS OF SCHIZOPHRENIA HAS YET TO BE FULLY ELUCIDATED, BUT COMMON THEMES INCLUDE NEUROPIL SHRINKAGE, THE DEVELOPMENT OF ABNORMAL NEURONAL CIRCUITRY, AND A CHRONIC INFLAMMATORY STATE WHICH FURTHER DISRUPTS NEURONAL FUNCTION. WHILST SOME EARLY NON-DOPAMINERGIC TREATMENTS SHOW PROMISE, NONE HAVE YET TO BE FULLY STUDIED IN APPROPRIATELY STRUCTURED RANDOMIZED CONTROLLED TRIALS AND THEY REMAIN LITTLE MORE THAN POTENTIAL ATTRACTIVE TARGETS. 2014 7 534 34 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 8 1796 50 EFFECT OF GERM-FREE STATUS ON TRANSCRIPTIONAL PROFILES IN THE NUCLEUS ACCUMBENS AND TRANSCRIPTOMIC RESPONSE TO CHRONIC MORPHINE. OPIOID USE DISORDER IS A PUBLIC HEALTH CRISIS THAT CAUSES TREMENDOUS SUFFERING FOR PATIENTS AS WELL AS SUBSTANTIAL SOCIAL AND ECONOMIC COSTS FOR SOCIETY. THERE ARE CURRENTLY AVAILABLE TREATMENTS FOR PATIENTS WITH OPIOID USE DISORDER, BUT THEY REMAIN INTOLERABLE OR INEFFECTIVE FOR MANY. THUS THE NEED TO DEVELOP NEW AVENUES FOR THERAPEUTICS DEVELOPMENT IN THIS SPACE IS GREAT. SUBSTANTIAL WORK IN MODELS OF SUBSTANCE USE DISORDERS, INCLUDING OPIOID USE DISORDER, DEMONSTRATES THAT PROLONGED EXPOSURE TO DRUGS OF ABUSE LEADS TO MARKED TRANSCRIPTIONAL AND EPIGENETIC DYSREGULATION IN LIMBIC SUBSTRUCTURES. IT IS WIDELY BELIEVED THAT THESE CHANGES IN GENE REGULATION IN RESPONSE TO DRUGS ARE A KEY DRIVING FACTOR IN THE PERPETUATION OF DRUG TAKING AND SEEKING BEHAVIORS. THUS, DEVELOPMENT OF INTERVENTIONS THAT COULD SHAPE TRANSCRIPTIONAL REGULATION IN RESPONSE TO DRUGS OF ABUSE WOULD BE OF HIGH VALUE. OVER THE PAST DECADE THERE HAS BEEN A SURGE IN RESEARCH DEMONSTRATING THAT THE RESIDENT BACTERIA OF THE GASTROINTESTINAL TRACT, COLLECTIVELY THE GUT MICROBIOME, CAN HAVE TREMENDOUS INFLUENCE ON NEUROBIOLOGICAL AND BEHAVIORAL PLASTICITY. PREVIOUS WORK FROM OUR GROUP AND OTHERS HAS DEMONSTRATED THAT ALTERATIONS IN THE GUT MICROBIOME CAN ALTER BEHAVIORAL RESPONSES TO OPIOIDS IN MULTIPLE PARADIGMS. ADDITIONALLY, WE HAVE PREVIOUSLY REPORTED THAT DEPLETION OF THE GUT MICROBIOME WITH ANTIBIOTICS MARKEDLY SHIFTS THE TRANSCRIPTOME OF THE NUCLEUS ACCUMBENS FOLLOWING PROLONGED MORPHINE EXPOSURE. IN THIS MANUSCRIPT WE PRESENT A COMPREHENSIVE ANALYSIS OF THE EFFECTS OF THE GUT MICROBIOME ON TRANSCRIPTIONAL REGULATION OF THE NUCLEUS ACCUMBENS FOLLOWING MORPHINE BY UTILIZING GERM-FREE, ANTIBIOTIC TREATED, AND CONTROL MICE. THIS ALLOWS FOR DETAILED UNDERSTANDING OF THE ROLE OF THE MICROBIOME IN REGULATING BASELINE TRANSCRIPTOMIC CONTROL, AS WELL AS RESPONSE TO MORPHINE. WE FIND THAT GERM-FREE STATUS LEADS TO A MARKED GENE DYSREGULATION IN A MANNER DISTINCT TO ADULT MICE TREATED WITH ANTIBIOTICS, AND THAT ALTERED GENE PATHWAYS ARE HIGHLY RELATED TO CELLULAR METABOLIC PROCESSES. THESE DATA PROVIDE ADDITIONAL INSIGHT INTO THE ROLE OF THE GUT MICROBIOME IN MODULATING BRAIN FUNCTION AND LAY A FOUNDATION FOR FURTHER STUDY IN THIS AREA. 2023 9 4633 37 NEUROIMMUNE ACTIVATION DRIVES MULTIPLE BRAIN STATES. NEUROIMMUNE SIGNALING IS INCREASINGLY IDENTIFIED AS A CRITICAL COMPONENT OF NEURONAL PROCESSES UNDERLYING MEMORY, EMOTION AND COGNITION. THE INTERACTIONS OF MICROGLIA AND ASTROCYTES WITH NEURONS AND SYNAPSES, AND THE INDIVIDUAL CYTOKINES AND IMMUNE SIGNALING MOLECULES THAT MEDIATE THESE INTERACTIONS ARE A CURRENT FOCUS OF MUCH RESEARCH. HERE, WE DISCUSS NEUROIMMUNE ACTIVATION AS A MECHANISM TRIGGERING DIFFERENT STATES THAT MODULATE COGNITIVE AND AFFECTIVE PROCESSES TO ALLOW FOR APPROPRIATE BEHAVIOR DURING AND AFTER ILLNESS OR INJURY. WE PROPOSE THAT THESE STATES LIE ON A CONTINUUM FROM A NAIVE HOMEOSTATIC BASELINE STATE IN THE ABSENCE OF STIMULATION, TO ACUTE NEUROIMMUNE ACTIVITY AND CHRONIC ACTIVATION. IMPORTANTLY, CONSEQUENCES OF ILLNESS OR INJURY INCLUDING COGNITIVE DEFICITS AND MOOD IMPAIRMENTS CAN PERSIST LONG AFTER RESOLUTION OF IMMUNE SIGNALING. THIS SUGGESTS THAT NEUROIMMUNE ACTIVATION ALSO RESULTS IN AN ENDURING SHIFT IN THE HOMEOSTATIC BASELINE STATE WITH LONG LASTING CONSEQUENCES FOR NEURAL FUNCTION AND BEHAVIOR. SUCH DIFFERENT STATES CAN BE IDENTIFIED IN A MULTIDIMENSIONAL WAY, USING PATTERNS OF CYTOKINE AND GLIAL ACTIVATION, BEHAVIORAL AND COGNITIVE CHANGES, AND EPIGENETIC SIGNATURES. IDENTIFYING DISTINCT NEUROIMMUNE STATES AND THEIR CONSEQUENCES FOR NEURAL FUNCTION WILL PROVIDE A FRAMEWORK FOR PREDICTING VULNERABILITY TO DISORDERS OF MEMORY, COGNITION AND EMOTION BOTH DURING AND LONG AFTER RECOVERY FROM ILLNESS. 2018 10 2011 45 EPIGENETIC BASIS OF MENTAL ILLNESS. PSYCHIATRIC DISORDERS ARE COMPLEX MULTIFACTORIAL ILLNESSES INVOLVING CHRONIC ALTERATIONS IN NEURAL CIRCUIT STRUCTURE AND FUNCTION AS WELL AS LIKELY ABNORMALITIES IN GLIAL CELLS. WHILE GENETIC FACTORS ARE IMPORTANT IN THE ETIOLOGY OF MOST MENTAL DISORDERS, THE RELATIVELY HIGH RATES OF DISCORDANCE AMONG IDENTICAL TWINS, PARTICULARLY FOR DEPRESSION AND OTHER STRESS-RELATED SYNDROMES, CLEARLY INDICATE THE IMPORTANCE OF ADDITIONAL MECHANISMS. ENVIRONMENTAL FACTORS SUCH AS STRESS ARE KNOWN TO PLAY A ROLE IN THE ONSET OF THESE ILLNESSES. EXPOSURE TO SUCH ENVIRONMENTAL INSULTS INDUCES STABLE CHANGES IN GENE EXPRESSION, NEURAL CIRCUIT FUNCTION, AND ULTIMATELY BEHAVIOR, AND THESE MALADAPTATIONS APPEAR DISTINCT BETWEEN DEVELOPMENTAL VERSUS ADULT EXPOSURES. INCREASING EVIDENCE INDICATES THAT THESE SUSTAINED ABNORMALITIES ARE MAINTAINED BY EPIGENETIC MODIFICATIONS IN SPECIFIC BRAIN REGIONS. INDEED, TRANSCRIPTIONAL DYSREGULATION AND THE ABERRANT EPIGENETIC REGULATION THAT UNDERLIES THIS DYSREGULATION IS A UNIFYING THEME IN PSYCHIATRIC DISORDERS. HERE, WE PROVIDE A PROGRESS REPORT OF EPIGENETIC STUDIES OF THE THREE MAJOR PSYCHIATRIC SYNDROMES, DEPRESSION, SCHIZOPHRENIA, AND BIPOLAR DISORDER. WE REVIEW THE LITERATURE DERIVED FROM ANIMAL MODELS OF THESE DISORDERS AS WELL AS FROM STUDIES OF POSTMORTEM BRAIN TISSUE FROM HUMAN PATIENTS. WHILE EPIGENETIC STUDIES OF MENTAL ILLNESS REMAIN AT EARLY STAGES, UNDERSTANDING HOW ENVIRONMENTAL FACTORS RECRUIT THE EPIGENETIC MACHINERY WITHIN SPECIFIC BRAIN REGIONS TO CAUSE LASTING CHANGES IN DISEASE SUSCEPTIBILITY AND PATHOPHYSIOLOGY IS REVEALING NEW INSIGHT INTO THE ETIOLOGY AND TREATMENT OF THESE CONDITIONS. 2016 11 6324 36 THE ROLE OF ALPHA-SYNUCLEIN IN THE PATHOPHYSIOLOGY OF ALCOHOLISM. ALCOHOLISM HAS COMPLEX ETIOLOGY AND THERE IS EVIDENCE FOR BOTH GENETIC AND ENVIRONMENTAL FACTORS IN ITS PATHOPHYSIOLOGY. CHRONIC, LONG-TERM ALCOHOL ABUSE AND ALCOHOL DEPENDENCE ARE ASSOCIATED WITH NEURONAL LOSS WITH THE PREFRONTAL CORTEX BEING PARTICULARLY SUSCEPTIBLE TO NEUROTOXIC DAMAGE. THIS BRAIN REGION IS INVOLVED IN THE DEVELOPMENT AND PERSISTENCE OF ALCOHOL ADDICTION AND NEUROTOXIC DAMAGE IS LIKELY TO EXACERBATE THE REINFORCING EFFECTS OF ALCOHOL AND MAY HINDER TREATMENT. UNDERSTANDING THE MECHANISM OF ALCOHOL'S NEUROTOXIC EFFECTS ON THE BRAIN AND THE GENETIC RISK FACTORS ASSOCIATED WITH ALCOHOL ABUSE ARE THE FOCUS OF CURRENT RESEARCH. BECAUSE OF ITS WELL-ESTABLISHED ROLE IN NEURODEGENERATIVE AND NEUROPSYCHOLOGICAL DISORDERS, AND ITS EMERGING ROLE IN THE PATHOPHYSIOLOGY OF ADDICTION, HERE WE REVIEW THE GENETIC AND EPIGENETIC FACTORS INVOLVED IN REGULATING ALPHA-SYNUCLEIN EXPRESSION AND ITS POTENTIAL ROLE IN THE PATHOPHYSIOLOGY OF CHRONIC ALCOHOL ABUSE. ELUCIDATION OF THE MECHANISMS OF ALPHA-SYNUCLEIN REGULATION MAY PROVE BENEFICIAL IN UNDERSTANDING THE ROLE OF THIS KEY SYNAPTIC PROTEIN IN DISEASE AND ITS POTENTIAL FOR THERAPEUTIC MODULATION IN THE TREATMENT OF SUBSTANCE USE DISORDERS AS WELL AS OTHER NEURODEGENERATIVE DISEASES. 2013 12 6414 39 THE STRESSED SYNAPSE 2.0: PATHOPHYSIOLOGICAL MECHANISMS IN STRESS-RELATED NEUROPSYCHIATRIC DISORDERS. STRESS IS A PRIMARY RISK FACTOR FOR SEVERAL NEUROPSYCHIATRIC DISORDERS. EVIDENCE FROM PRECLINICAL MODELS AND CLINICAL STUDIES OF DEPRESSION HAVE REVEALED AN ARRAY OF STRUCTURAL AND FUNCTIONAL MALADAPTIVE CHANGES, WHEREBY ADVERSE ENVIRONMENTAL FACTORS SHAPE THE BRAIN. THESE CHANGES, OBSERVED FROM THE MOLECULAR AND TRANSCRIPTIONAL LEVELS THROUGH TO LARGE-SCALE BRAIN NETWORKS, TO THE BEHAVIOURS REVEAL A COMPLEX MATRIX OF INTERRELATED PATHOPHYSIOLOGICAL PROCESSES THAT DIFFER BETWEEN SEXES, PROVIDING INSIGHT INTO THE POTENTIAL UNDERPINNINGS OF THE SEX BIAS OF NEUROPSYCHIATRIC DISORDERS. ALTHOUGH MANY PRECLINICAL STUDIES USE CHRONIC STRESS PROTOCOLS, LONG-TERM CHANGES ARE ALSO INDUCED BY ACUTE EXPOSURE TO TRAUMATIC STRESS, OPENING A PATH TO IDENTIFY DETERMINANTS OF RESILIENT VERSUS SUSCEPTIBLE RESPONSES TO BOTH ACUTE AND CHRONIC STRESS. EPIGENETIC REGULATION OF GENE EXPRESSION HAS EMERGED AS A KEY PLAYER UNDERLYING THE PERSISTENT IMPACT OF STRESS ON THE BRAIN. INDEED, HISTONE MODIFICATION, DNA METHYLATION AND MICRORNAS ARE CLOSELY INVOLVED IN MANY ASPECTS OF THE STRESS RESPONSE AND REVEAL THE GLUTAMATE SYSTEM AS A KEY PLAYER. THE SUCCESS OF KETAMINE HAS STIMULATED A WHOLE LINE OF RESEARCH AND DEVELOPMENT ON DRUGS DIRECTLY OR INDIRECTLY TARGETING GLUTAMATE FUNCTION. HOWEVER, THE CHALLENGE OF TRANSLATING THE EMERGING UNDERSTANDING OF STRESS PATHOPHYSIOLOGY INTO EFFECTIVE CLINICAL TREATMENTS REMAINS A MAJOR CHALLENGE. 2022 13 2963 29 GENETIC AND EPIGENETIC MECHANISMS LINKING PAIN AND PSYCHIATRIC DISORDERS. THE NEUROPHYSIOLOGICAL LINK BETWEEN NEUROPATHIC PAIN AND DEPRESSION REMAINS UNKNOWN DESPITE EVIDENT HIGH COMORBIDITY OF THESE TWO DISORDERS. HOWEVER, THERE IS CONVINCING EVIDENCE THAT GENOTYPE PLAYS A ROLE IN BOTH PAIN AND DEPRESSION. USING VARIOUS TYPES OF GENETIC ANALYSIS - POPULATION GENETICS, CYTOGENETICS AND MOLECULAR TECHNOLOGIES - SPECIFIC GENES HAVE BEEN IMPLICATED IN MEDIATING ALMOST ALL ASPECTS OF NOCICEPTION AND MOOD DISORDERS. THE CURRENT REVIEW ATTEMPTS TO IDENTIFY SPECIFIC GENES AND EPIGENETIC MECHANISMS COMMON TO BOTH DISORDERS. IT IS CONCLUDED THAT EXTERNAL AND INTERNAL FACTORS (INFLAMMATION, STRESS, GENDER, ETC.) THAT CONTRIBUTE TO THE PATHOLOGIES MAY DO SO THROUGH EPIGENETIC MECHANISMS THAT MAY AFFECT EXPRESSION OF THESE PARTICULAR GENES. THE POSSIBLE INVOLVEMENT OF EPIGENETIC REGULATION IN PAIN AND PSYCHIATRIC DISORDERS SUGGESTS THAT TREATMENTS TARGETING EPIGENETIC MECHANISMS THAT MEDIATE ADVERSE LIFE EVENTS SHOULD BE CONSIDERED. 2015 14 1329 39 DEPRESSION ASSOCIATED WITH DIABETES: FROM PATHOPHYSIOLOGY TO TREATMENT. DIABETES IS A CHRONIC AND PROGRESSIVE SYNDROME COMMONLY ASSOCIATED WITH SEVERAL NEUROPSYCHIATRIC COMORBITIES, OF WHICH DEPRESSION IS THE MOST STUDIED. THE PREVALENCE OF DEPRESSION IS ABOUT TWO OR THREE TIMES HIGHER IN DIABETIC PATIENTS COMPARED TO THE GENERAL POPULATION. IT IS BELIEVED THAT THE DIABETES - DEPRESSION RELATION MAY BE BIDIRECTIONAL, I.E., THE DEPRESSION CAN LEAD TO DIABETES AND CONVERSELY DIABETES COULD FACILITATE THE EMERGENCE OF DEPRESSION. DEPRESSION IS ONE OF THE MOST NEGLECTED SYMPTOMS IN DIABETIC PATIENTS AND IS DIRECTLY LINKED WITH LOWERING OF QUALITY OF LIFE. THE TREATMENT OF DEPRESSION IN THESE PATIENTS IS STILL QUITE INEFFECTIVE AND IN MANY CASES TREATMENTREFRACTORY. FURTHERMORE, SOME OF THE FIRST CHOICE DRUGS USED TO TREAT THE DEPRESSION AFFECT THE BLOOD GLUCOSE CONTROL, AGGRAVATING THE HYPERGLYCEMIC STATE. THESE ISSUES UNDERSCORE THE URGENCY IN STUDIES SEARCHING FOR NEW PHARMACOLOGICAL TARGETS FOR THE TREATMENT OF DEPRESSION ASSOCIATED WITH DIABETES. FOR THIS, A BETTER UNDERSTANDING OF THE PATHOPHYSIOLOGY THAT RELATES THIS COMORBIDITY BECOMES CRITICAL. IN THIS RESPECT, THIS REVIEW WILL FOCUS ON SOME HYPOTHESES THAT HAVE BEEN PROPOSED TO EXPLAIN THE MECHANISMS UNDERLYING DEPRESSION ASSOCIATED WITH DIABETES, HIGHLIGHTING THE TREATMENT OPTIONS CURRENTLY AVAILABLE AND THEIR LIMITATIONS. AMONG THESE HYPOTHESES, WE WILL POINT OUT THE HYPERGLYCEMIA AS A PRIMARY METABOLIC CAUSE OF THE DEPRESSION DEVELOPMENT, THE INVOLVEMENT OF THE DYSREGULATION OF HYPOTHALAMIC PITUITARY-ADRENAL (HPA) AXIS AND OF NEUROTRANSMITTER SYSTEMS, SPECIALLY MONOAMINERGIC SYSTEM. BESIDES, THE ROLE OF OXIDATIVE STRESS, NEUROINFLAMMATION AND CELL DEATH, ESPECIALLY IN HIPPOCAMPUS AND PREFRONTAL CORTEX, BRAIN AREAS IMPORTANT FOR THE MEDIATION AND MODULATION OF EMOTIONAL BEHAVIOR WILL ALSO BE DISCUSSED. FINALLY, WE WILL BRING UP THE INFLUENCE OF THE EPIGENETIC REGULATION WITH RESPECT TO NEUROPSYCHIATRIC DISORDERS. 2016 15 6775 33 [ALCOHOL DEPENDENCE MEDIATED BY MONOAMINE NEUROTRANSMITTERS IN THE CENTRAL NERVOUS SYSTEM]. ALCOHOL DEPENDENCE, A CHRONIC RELAPSING BRAIN DISEASE WITH THE CHARACTERISTICS OF DRINKING ALCOHOL OUT OF CONTROL, HAS BECOME A SERIOUS SOCIAL PROBLEM. MONOAMINE NEUROTRANSMITTERS, MAINLY INCLUDING DOPAMINE AND 5-HYDROXYTRYP NOTTAMINE, PLAY IMPORTANT ROLES IN THE OCCURRENCE, DEVELOPMENT AND NEURAL DYSFUNCTION OF ALCOHOL DEPENDENCE SYNDROME. IN THIS REVIEW, THE ROLES OF KEY FACTORS OF THE MONOAMINE SYSTEM (DOPAMINE RECEPTOR GENES, 5-HYDROXYTRYPTAMINE RECEPTOR GENES, TRANSPORTER GENES, TYROSINE HYDROXYLASE GENE, TRYPTOPHANHYDROXYLASE GENE AND MONOAMINE OXIDASE GENE) IN ALCOHOL DEPENDENCE WERE DISCUSSED, AND STRATEGIES FOR FURTHER STUDIES OF MOLECULAR MECHANISMS WERE PROPOSED BASED ON GENE KNOCKOUT MICE MODELS GENERATED IN OUR LABORATORY. THEN, COMBINING WITH STUDIES ON TYROSINE HYDROXYLASE ACTIVATOR CAMKII IN OUR LAB, THERAPEUTIC TARGETS WERE DISCUSSED. BESIDES, EPIGENETIC STRATEGIES FOR PREVENTION AND TREATMENT OF ALCOHOL DEPENDENCE SYNDROME WERE PROPOSED. FURTHERMORE, MANIPULATING METHYLATION LEVELS IN GENE REGULATORY REGIONS AND ALTERNATIVE SPLICING OF PRE-MRNAS MIGHT ALSO HAVE CLINICAL IMPLICATIONS. FINALLY, BASED ON NEW FINDINGS ON GENETIC POLYMORPHISM, IT IS OF GREAT POTENTIAL TO CARRY OUT INDIVIDUAL PREVENTION AND TREATMENT FOR PATIENTS SUFFERING FROM ALCOHOL DEPENDENCE. 2014 16 4206 46 METABOTROPIC GLUTAMATE 2/3 RECEPTORS AND EPIGENETIC MODIFICATIONS IN PSYCHOTIC DISORDERS: A REVIEW. SCHIZOPHRENIA AND BIPOLAR DISORDER ARE CHRONIC PSYCHIATRIC DISORDERS, BOTH CONSIDERED AS "MAJOR PSYCHOSIS"; THEY ARE THOUGHT TO SHARE SOME PATHOGENETIC FACTORS INVOLVING A DYSFUNCTIONAL GENE X ENVIRONMENT INTERACTION. ALTERATIONS IN THE GLUTAMATERGIC TRANSMISSION HAVE BEEN SUGGESTED TO BE INVOLVED IN THE PATHOGENESIS OF PSYCHOSIS. OUR GROUP DEVELOPED AN EPIGENETIC MODEL OF SCHIZOPHRENIA ORIGINATED BY PRENATAL RESTRAINT STRESS (PRS) PARADIGM IN MICE. PRS MICE DEVELOPED SOME BEHAVIORAL ALTERATIONS OBSERVED IN SCHIZOPHRENIC PATIENTS AND CLASSIC ANIMAL MODELS OF SCHIZOPHRENIA, I.E. DEFICITS IN SOCIAL INTERACTION, LOCOMOTOR ACTIVITY AND PREPULSE INHIBITION. THEY ALSO SHOWED SPECIFIC CHANGES IN PROMOTER DNA METHYLATION ACTIVITY OF GENES RELATED TO SCHIZOPHRENIA SUCH AS REELIN, BDNF AND GAD67, AND ALTERED EXPRESSION AND FUNCTION OF MGLU2/3 RECEPTORS IN THE FRONTAL CORTEX. INTERESTINGLY, BEHAVIORAL AND MOLECULAR ALTERATIONS WERE REVERSED BY TREATMENT WITH MGLU2/3 AGONISTS. BASED ON THESE FINDINGS, WE SPECULATE THAT PHARMACOLOGICAL MODULATION OF THESE RECEPTORS COULD HAVE A GREAT IMPACT ON EARLY PHASE TREATMENT OF PSYCHOSIS TOGETHER WITH THE POSSIBILITY TO MODULATE SPECIFIC EPIGENETIC KEY PROTEIN INVOLVED IN THE DEVELOPMENT OF PSYCHOSIS. IN THIS REVIEW, WE WILL DISCUSS IN MORE DETAILS THE SPECIFIC FEATURES OF THE PRS MICE AS A SUITABLE EPIGENETIC MODEL FOR MAJOR PSYCHOSIS. WE WILL THEN FOCUS ON KEY PROTEINS OF CHROMATIN REMODELING MACHINERY AS POTENTIAL TARGET FOR NEW PHARMACOLOGICAL TREATMENT THROUGH THE ACTIVATION OF METABOTROPIC GLUTAMATE RECEPTORS. 2016 17 4642 41 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 18 38 32 A COMMON ROLE FOR PSYCHOTROPIC MEDICATIONS: MEMORY IMPAIRMENT. THE PSYCHOPATHOLOGIC PROFILE OF MENTAL DISORDERS IS VERY DIVERSE AND PSYCHOTROPIC MEDICATIONS USED TO TREAT THEM DIFFER IN THEIR CHEMICAL STRUCTURE. NEVERTHELESS, THESE DRUGS SHARE THESE FOUR CHARACTERISTICS: DELAYED ONSET OF CLINICAL RESPONSE, NOT ONE OF THEM CAN BE SAID TO CURE, THERE IS A HIGH NUMBER OF NON-RESPONDERS, AND THE MECHANISM RESPONSIBLE FOR THEIR THERAPEUTIC ACTION IS NOT KNOWN. IT IS HYPOTHESIZED THAT THE ACTION OF PSYCHOTROPIC MEDICATIONS IS MEMORY IMPAIRMENT, UNDERSTANDING MEMORY AS THE TRACE LEFT IN THE NERVOUS SYSTEM NOT ONLY BY INDIVIDUAL EXPERIENCES BUT ALSO BY GENETIC AND EPIGENETIC PHENOMENA. IT IS SUGGESTED THAT IT WOULD BE BENEFICIAL TO TRANSLATE SOME RESEARCH STRATEGIES FROM THE NEUROBIOLOGY OF LEARNING AND MEMORY TO THE STUDY OF THE EFFECTS OF PSYCHOTROPIC MEDICATIONS. THE HYPOTHESIS IS BRIEFLY ASSESSED ACCORDING TO THE FOLLOWING THREE CRITERIA: (A). THE COMPARISON BETWEEN THE MOLECULAR EFFECTS OF PSYCHOTROPIC MEDICATIONS AND THE SO-CALLED MOLECULAR BIOLOGY OF LEARNING AND MEMORY, (B). THE EFFECTS OF THESE DRUGS, PREFERENTIALLY AFTER CHRONIC USE, ON MEMORY TESTS, AND (C). THE EFFECTS OF DRUGS THAT IMPAIR MEMORY ON TESTS USED FOR SCREENING PSYCHOTROPIC MEDICATIONS. FINALLY, SOME GENERAL SUGGESTIONS FOR FUTURE RESEARCH ARE POINTED OUT. 2003 19 6866 34 [PAIN AND EMOTIONAL DYSREGULATION: CELLULAR MEMORY DUE TO PAIN]. GENETIC FACTORS ARE INVOLVED IN DETERMINANTS FOR THE RISK OF PSYCHIATRIC DISORDERS, AND NEUROLOGICAL AND NEURODEGENERATIVE DISEASES. CHRONIC PAIN STIMULI AND INTENSE PAIN HAVE EFFECTS AT A CELLULAR AND/OR GENE EXPRESSION LEVEL, AND WILL EVENTUALLY INDUCE "CELLULAR MEMORY DUE TO PAIN", WHICH MEANS THAT TISSUE DAMAGE, EVEN IF ONLY TRANSIENT, CAN ELICIT EPIGENETICALLY ABNORMAL TRANSCRIPTION/TRANSLATION AND POST-TRANSLATIONAL MODIFICATION IN RELATED CELLS DEPENDING ON THE DEGREE OR KIND OF INJURY OR ASSOCIATED CONDITIONS. SUCH CELL MEMORY/TRANSFORMATION DUE TO PAIN CAN CAUSE AN ABNORMALITY IN A FUNDAMENTAL INTRACELLULAR RESPONSE, SUCH AS A CHANGE IN THE THREE-DIMENSIONAL STRUCTURE OF DNA, TRANSCRIPTION, OR TRANSLATION. ON THE OTHER HAND, PAIN IS A MULTIDIMENSIONAL EXPERIENCE WITH SENSORY-DISCRIMINATIVE AND MOTIVATIONAL-AFFECTIVE COMPONENTS. RECENT HUMAN BRAIN IMAGING STUDIES HAVE EXAMINED DIFFERENCES IN ACTIVITY IN THE NUCLEUS ACCUMBENS BETWEEN CONTROLS AND PATIENTS WITH CHRONIC PAIN, AND HAVE REVEALED THAT THE NUCLEUS ACCUMBENS PLAYS A ROLE IN PREDICTING THE VALUE OF A NOXIOUS STIMULUS AND ITS OFFSET, AND IN THE CONSEQUENT CHANGES IN THE MOTIVATIONAL STATE. IN THIS REVIEW, WE PROVIDE A VERY BRIEF OVERVIEW OF A COMPREHENSIVE UNDERSTANDING OF CHRONIC PAIN ASSOCIATED WITH EMOTIONAL DYSREGULATION DUE TO TRANSCRIPTIONAL REGULATION, EPIGENETIC MODIFICATION AND MIRNA REGULATION. 2015 20 252 47 ADVANCEMENTS IN THE UNDERLYING PATHOGENESIS OF SCHIZOPHRENIA: IMPLICATIONS OF DNA METHYLATION IN GLIAL CELLS. SCHIZOPHRENIA (SZ) IS A CHRONIC AND SEVERE MENTAL ILLNESS FOR WHICH CURRENTLY THERE IS NO CURE. AT PRESENT, THE EXACT MOLECULAR MECHANISM INVOLVED IN THE UNDERLYING PATHOGENESIS OF SZ IS UNKNOWN. THE DISEASE IS THOUGHT TO BE CAUSED BY A COMBINATION OF GENETIC, BIOLOGICAL, PSYCHOLOGICAL, AND ENVIRONMENTAL FACTORS. RECENT STUDIES HAVE SHOWN THAT EPIGENETIC REGULATION IS INVOLVED IN SZ PATHOLOGY. SPECIFICALLY, DNA METHYLATION, ONE OF THE EARLIEST FOUND EPIGENETIC MODIFICATIONS, HAS BEEN EXTENSIVELY LINKED TO MODULATION OF NEURONAL FUNCTION, LEADING TO PSYCHIATRIC DISORDERS SUCH AS SZ. HOWEVER, INCREASING EVIDENCE INDICATES THAT GLIAL CELLS, ESPECIALLY DYSFUNCTIONAL OLIGODENDROCYTES UNDERGO DNA METHYLATION CHANGES THAT CONTRIBUTE TO THE PATHOGENESIS OF SZ. THIS REVIEW PRIMARILY FOCUSES ON DNA METHYLATION INVOLVED IN GLIAL DYSFUNCTIONS IN SZ. CLARIFYING THIS MECHANISM MAY LEAD TO THE DEVELOPMENT OF NEW THERAPEUTIC INTERVENTIONAL STRATEGIES FOR THE TREATMENT OF SZ AND OTHER ILLNESSES BY CORRECTING ABNORMAL METHYLATION IN GLIAL CELLS. 2015