1 4500 151 MORPHINE-WITHDRAWAL AVERSIVE MEMORIES AND THEIR EXTINCTION MODULATE H4K5 ACETYLATION AND BRD4 ACTIVATION IN THE RAT HIPPOCAMPUS AND BASOLATERAL AMYGDALA. CHROMATIN MODIFICATION IS A CRUCIAL MECHANISM IN SEVERAL IMPORTANT PHENOMENA IN THE BRAIN, INCLUDING DRUG ADDICTION. PERSISTENCE OF DRUG CRAVING AND RISK OF RELAPSE COULD BE ATTRIBUTED TO DRUG-INDUCED EPIGENETIC MECHANISMS THAT SEEM TO BE CANDIDATES EXPLAINING LONG-LASTING DRUG-INDUCED BEHAVIOUR AND MOLECULAR ALTERATIONS. HISTONE ACETYLATION HAS BEEN PROPOSED TO REGULATE DRUG-SEEKING BEHAVIOURS AND THE EXTINCTION OF REWARDING MEMORY OF DRUG TAKING. IN THIS WORK, WE STUDIED THE EPIGENETIC REGULATION DURING CONDITIONED PLACE AVERSION AND AFTER EXTINCTION OF AVERSIVE MEMORY OF OPIATE WITHDRAWAL. THROUGH IMMUNOFLUORESCENCE ASSAYS, WE ASSESSED SOME EPIGENETIC MARKS (H4K5AC AND P-BRD4) IN CRUCIAL AREAS RELATED TO MEMORY RETRIEVAL -BASOLATERAL AMYGDALA (BLA) AND HIPPOCAMPUS-. ADDITIONALLY, TO TEST THE DEGREE OF TRANSCRIPTIONAL ACTIVATION, WE EVALUATED THE IMMEDIATE EARLY GENES (IEGS) RESPONSE (ARC, BDNF, CREB, EGR-1, FOS AND NFKB) AND SMARCC1 (CHROMATIN REMODELER) THROUGH RT-QPCR IN THESE NUCLEI. OUR RESULTS SHOWED INCREASED P-BRD4 AND H4K5AC LEVELS DURING AVERSIVE MEMORY RETRIEVAL, SUGGESTING A MORE OPEN CHROMATIN STATE. HOWEVER, TRANSCRIPTIONAL ACTIVATION OF THESE IEGS WAS NOT FOUND, THEREFORE SUGGESTING THAT OTHER SECONDARY RESPONSE MAY ALREADY BE HAPPENING. ADDITIONALLY, SMARCC1 LEVELS WERE REDUCED DUE TO MORPHINE CHRONIC ADMINISTRATION IN BLA AND DENTATE GYRUS. THE ACTIVATION MARKERS RETURNED TO CONTROL LEVELS AFTER THE RETRIEVAL OF AVERSIVE MEMORIES, REVEALING A MORE REPRESSED CHROMATIN STATE. TAKEN TOGETHER, OUR RESULTS SHOW A MAJOR ROLE OF THE TANDEM H4K5AC/P-BRD4 DURING THE RETRIEVAL OF AVERSIVE MEMORIES. THESE RESULTS MIGHT BE USEFUL TO ELUCIDATE NEW MOLECULAR TARGETS TO IMPROVE AND DEVELOP PHARMACOLOGICAL TREATMENTS TO ADDRESS ADDICTION AND TO AVOID DRUG RELAPSE. 2023 2 5970 23 TESTOSTERONE ACTS WITHIN THE MEDIAL AMYGDALA OF RATS TO REDUCE INNATE FEAR TO PREDATOR ODOR AKIN TO THE EFFECTS OF TOXOPLASMA GONDII INFECTION. RATS INFECTED WITH THE PROTOZOAN TOXOPLASMA GONDII EXHIBIT A REDUCED AVERSION TO CAT ODOR. THIS BEHAVIORAL CHANGE IS THOUGHT TO INCREASE TROPHIC TRANSMISSION OF THE PARASITE. INFECTED MALE RATS ALSO SHOW A GREATER TESTICULAR SYNTHESIS OF TESTOSTERONE AND EPIGENETIC CHANGE IN ARGININE VASOPRESSIN WITHIN THE MEDIAL AMYGDALA. HERE, WE SHOW THAT EXOGENOUS SUPPLY OF TESTOSTERONE WITHIN MEA OF UNINFECTED CASTRATES RECAPITULATES REDUCTION IN INNATE FEAR AKIN TO BEHAVIORAL CHANGE ATTRIBUTED TO THE PARASITE. WE ALSO SHOW THAT CASTRATION POST ESTABLISHMENT OF CHRONIC INFECTION PRECLUDES CHANGES IN FEAR AND MEDIAL AMYGDALA ARGININE VASOPRESSIN IN THE INFECTED MALE RATS. THESE OBSERVATIONS SUPPORT THE ROLE OF GONADAL HORMONES AND PURSUANT NEUROENDOCRINE CHANGES IN MEDIATING THE LOSS OF FEAR IN THE INFECTED RATS. THIS WORK ALSO DEMONSTRATES THAT TESTOSTERONE ACTING SPECIFICALLY WITHIN THE MEDIAL AMYGDALA SUFFICIENTLY EXPLAINS REDUCED DEFENSIVE BEHAVIORS OFTEN OBSERVED DURING THE APPETITIVE COMPONENT OF REPRODUCTIVE BEHAVIORS. 2020 3 5876 23 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 4 2670 34 ETHANOL ACTIONS ON THE VENTRAL TEGMENTAL AREA: NOVEL POTENTIAL TARGETS ON REWARD PATHWAY NEURONS. THE VENTRAL TEGMENTAL AREA (VTA) EVALUATES SALIENCE OF ENVIRONMENTAL STIMULI AND PROVIDES DOPAMINERGIC INNERVATION TO MANY BRAIN AREAS AFFECTED BY ACUTE AND CHRONIC ETHANOL EXPOSURE. WHILE PRIMARILY ASSOCIATED WITH REWARDING AND REINFORCING STIMULI, RECENT EVIDENCE INDICATES A ROLE FOR THE VTA IN AVERSION AS WELL. ETHANOL ACTIONS IN THE VTA MAY TRIGGER NEUROADAPTATION RESULTING IN REDUCTION OF THE AVERSIVE RESPONSES TO ALCOHOL AND A RELATIVE INCREASE IN THE REWARDING RESPONSES. IN SEARCHING FOR EFFECTIVE PHARMACOTHERAPIES FOR THE TREATMENT OF ALCOHOL ABUSE AND ALCOHOLISM, RECOGNITION OF THIS IMBALANCE MAY REVEAL NOVEL STRATEGIES. IN ADDITION TO CONVENTIONAL RECEPTOR/ION CHANNEL PHARMACOTHERAPIES, EPIGENETIC FACTORS THAT CONTROL NEUROADAPTATION TO CHRONIC ETHANOL TREATMENT CAN BE TARGETED AS AN AVENUE FOR DEVELOPMENT OF THERAPEUTIC APPROACHES TO RESTORE THE BALANCE. FURTHERMORE, WHEN EXPLORING THERAPIES TO ADDRESS REWARD/AVERSION IMBALANCE IN THE ACTION OF ALCOHOL IN THE VTA, SEX DIFFERENCES HAVE TO BE TAKEN INTO ACCOUNT TO ENSURE EFFECTIVE TREATMENT FOR BOTH MEN AND WOMEN. THESE PRINCIPLES APPLY TO A VTA-CENTRIC APPROACH TO THERAPIES, BUT SHOULD HOLD TRUE WHEN THINKING ABOUT THE OVERALL APPROACH IN THE DEVELOPMENT OF NEUROACTIVE DRUGS TO TREAT ALCOHOL USE DISORDERS. ALTHOUGH THE FUNCTIONS OF THE VTA ITSELF ARE COMPLEX, IT IS A USEFUL MODEL SYSTEM TO EVALUATE THE REWARD/AVERSION IMBALANCE THAT OCCURS WITH ETHANOL EXPOSURE AND COULD BE USED TO PROVIDE NEW LEADS IN THE EFFORTS TO DEVELOP NOVEL DRUGS TO TREAT ALCOHOLISM. 2018 5 5201 37 PRENATAL MORPHINE EXPOSURE INCREASES GAMMA OSCILLATION AND THETA COHERENCE IN THE RAT REWARD SYSTEM. PREVIOUS STUDIES HAVE FOUND THAT PRENATAL MORPHINE (PNM) EXPOSURE LEADS TO BOTH INCREASED AND DECREASED RISK OF SUBSTANCE ABUSE IN OFFSPRING. UNDERSTANDING MORE ABOUT THE NEUROBIOLOGICAL CHANGES AFTER THE PNM EXPOSURE WOULD HELP TO UNDERSTAND MORE ABOUT THIS ISSUE. SIGNALING FROM DOPAMINE NEURONS OF THE VENTRAL TEGMENTAL AREA (VTA) IN THE MESOACCUMBAL AND MESOCORTICAL PATHWAYS PLAYS A VITAL ROLE IN DRUG DEPENDENCY. TO PROVIDE FURTHER KNOWLEDGE ABOUT THE EFFECTS OF PNM ON DRUG SEEKING BEHAVIOR AND THE DOPAMINE SYSTEM. WE RECORDED LOCAL FIELD POTENTIALS (LFP) SIMULTANEOUSLY IN THE VTA, NAC (NUCLEUS ACCUMBENS), BLA (BASOLATERAL AMYGDALA) AND MPFC (MEDIAL PREFRONTAL CORTEX) IN MALE ADULT RATS PRENATALLY TREATED WITH SALINE OR MORPHINE. MORPHINE (10 MG/KG) INDUCED CONDITIONED PLACE PREFERENCE (CPP) ESTABLISHMENT, EXTINCTION AND PRIMING WERE TESTED TO INVESTIGATE THE EFFECTS OF PNM ON ADDICTIVE-LIKE BEHAVIOR. IN ADDITION, THE EXPRESSION OF NUCLEAR HISTONE DEACETYLASES (HDAC4, HDAC5), WHICH PLAYS ESSENTIAL EPIGENETIC ROLES IN NEUROPLASTICITY AFTER DRUG USE WERE ALSO TESTED IN VTA AND NAC. THE RESULTS SHOWED THAT PNM DID NOT CHANGE THE ACQUISITION OF MORPHINE CPP IN MALE RATS, BUT IMPAIRED CPP EXTINCTION AND MORPHINE (5 MG/KG) - PRIMED REINSTATEMENT OF CPP AFTER EXTINCTION. PNM INCREASED THE LOW GAMMA (30-60 HZ) AND HIGH (60-90 HZ) GAMMA LFP POWERS IN NAC AND BLA. PNM ALSO LEADS TO INCREASED THETA (4-9 HZ) COHERENCE BETWEEN VTA AND NAC, AND INCREASED HDAC5 EXPRESSION IN VTA. AFTER CHRONIC MORPHINE ADMINISTRATION, COHERENCE BETWEEN VTA-NAC, MPFC-NAC AND MPFC-BLA INCREASED SIGNIFICANTLY IN PNS RATS, BUT NO CHANGES WERE FIND IN PNM RATS, INDICATING IMPAIRED PLASTICITY IN BRAIN CIRCUITS. ALL THESE RESULTS SUGGEST THAT PNM EXPOSURE INCREASED REWARD PROCESSING IN ADULT MALE RATS, BUT IMPAIRED MORPHINE CPP EXTINCTION AND REINSTATEMENT, WHICH RELATE TO DECREASES NETWORK PLASTICITY AND INCREASED HDAC5 EXPRESSION IN THE REWARD SYSTEM. 2022 6 3587 38 IMPACT OF TLR4 ON BEHAVIORAL AND COGNITIVE DYSFUNCTIONS ASSOCIATED WITH ALCOHOL-INDUCED NEUROINFLAMMATORY DAMAGE. TOLL-LIKE RECEPTORS (TLRS) PLAY AN IMPORTANT ROLE IN THE INNATE IMMUNE RESPONSE, AND EMERGING EVIDENCE INDICATES THEIR ROLE IN BRAIN INJURY AND NEURODEGENERATION. OUR RECENT RESULTS HAVE DEMONSTRATED THAT ETHANOL IS CAPABLE OF ACTIVATING GLIAL TLR4 RECEPTORS AND THAT THE ELIMINATION OF THESE RECEPTORS IN MICE PROTECTS AGAINST ETHANOL-INDUCED GLIAL ACTIVATION, INDUCTION OF INFLAMMATORY MEDIATORS AND APOPTOSIS. THIS STUDY WAS DESIGNED TO ASSESS WHETHER ETHANOL-INDUCED INFLAMMATORY DAMAGE CAUSES BEHAVIORAL AND COGNITIVE CONSEQUENCES, AND IF BEHAVIORAL ALTERATIONS ARE DEPENDENT OF TLR4 FUNCTIONS. HERE WE SHOW IN MICE DRINKING ALCOHOL FOR 5MONTHS, FOLLOWED BY A 15-DAY WITHDRAWAL PERIOD, THAT ACTIVATION OF THE ASTROGLIAL AND MICROGLIAL CELLS IN FRONTAL CORTEX AND STRIATUM IS MAINTAINED AND THAT THESE EVENTS ARE ASSOCIATED WITH COGNITIVE AND ANXIETY-RELATED BEHAVIORAL IMPAIRMENTS IN WILD-TYPE (WT) MICE, AS DEMONSTRATED BY TESTING THE ANIMALS WITH OBJECT MEMORY RECOGNITION, CONDITIONED TASTE AVERSION AND DARK AND LIGHT BOX ANXIETY TASKS. MICE LACKING TLR4 RECEPTORS ARE PROTECTED AGAINST ETHANOL-INDUCED INFLAMMATORY DAMAGE, AND BEHAVIORAL ASSOCIATED EFFECTS. WE FURTHER ASSESS THE POSSIBILITY OF THE EPIGENETIC MODIFICATIONS PARTICIPATING IN SHORT- OR LONG-TERM BEHAVIORAL EFFECTS ASSOCIATED WITH NEUROINFLAMMATORY DAMAGE. WE SHOW THAT CHRONIC ALCOHOL TREATMENT DECREASES H4 HISTONE ACETYLATION AND HISTONE ACETYLTRANSFERASES ACTIVITY IN FRONTAL CORTEX, STRIATUM AND HIPPOCAMPUS OF WT MICE. ALTERATIONS IN CHROMATIN STRUCTURE WERE NOT OBSERVED IN TLR4(-/-) MICE. THESE RESULTS PROVIDE THE FIRST EVIDENCE OF THE ROLE THAT TLR4 FUNCTIONS PLAY IN THE BEHAVIORAL CONSEQUENCES OF ALCOHOL-INDUCED INFLAMMATORY DAMAGE AND SUGGEST THAT THE EPIGENETIC MODIFICATIONS MEDIATED BY TLR4 COULD CONTRIBUTE TO SHORT- OR LONG-TERM ALCOHOL-INDUCED BEHAVIORAL OR COGNITIVE DYSFUNCTIONS. 2011 7 5535 35 ROLE OF BRD4 PHOSPHORYLATION IN THE NUCLEUS ACCUMBENS IN RELAPSE TO COCAINE-SEEKING BEHAVIOR IN MICE. COCAINE ADDICTION IS A CHRONIC RELAPSING BRAIN DISORDER CHARACTERIZED BY COMPULSIVE DRUG SEEKING. PRELIMINARY STUDY SUGGESTED THAT BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4), AN EPIGENETIC READER PROTEIN, PARTICIPATES IN COCAINE-INDUCED REWARD AND NEUROPLASTICITY. HOWEVER, THE EXACT ROLE OF BRD4 IN COCAINE ADDICTION, PARTICULARLY COCAINE RELAPSE, REMAINS ELUSIVE. IN THIS STUDY, WE FOUND THAT BRD4 PHOSPHORYLATION IN THE NUCLEUS ACCUMBENS (NAC) WAS CLOSELY RELATED TO THE MAINTENANCE OF COCAINE REINFORCEMENT AND RELAPSE IN DIFFERENT COCAINE EXPOSURE PARADIGMS. COCAINE SIGNIFICANTLY INCREASED THE BINDING OF PHOSPHORYLATED BRD4 (PBRD4) AT THE PROMOTER OF GRIA2 AND BDNF GENES IN THE NAC. (+)JQ1, A SELECTIVE BRD4 INHIBITOR, MARKEDLY REDUCED THE REINFORCEMENT AND REINSTATEMENT OF COCAINE-SEEKING BEHAVIORS, WHICH WAS ACCOMPANIED BY THE DECREASED EXPRESSIONS OF GRIA2 AND BDNF. FURTHERMORE, CHROMATIN IMMUNOPRECIPITATION ASSAY SHOWED THAT (+)JQ1 CLEARLY ATTENUATED COCAINE-ENHANCED BINDING OF PBRD4 AT THE PROMOTOR OF GRIA2 AND BDNF GENES. BLOCKADE OF CASEIN KINASE II SIGNIFICANTLY ATTENUATED BRD4 PHOSPHORYLATION AND COCAINE RELAPSE-LIKE BEHAVIORS, SUGGESTING THE IMPORTANT ROLE OF PBRD4 IN MODULATING COCAINE EFFECT. TOGETHER, OUR FINDINGS SUGGEST THAT BRD4 PHOSPHORYLATION IN THE NAC MODULATES MULTIPLE ADDICTION-RELATED BEHAVIORS OF COCAINE AND PARTICULARLY RELAPSE TO COCAINE-SEEKING BEHAVIORS. INHIBITION OF BRD4 ACTIVITY MAY BE A NOVEL TARGET AGAINST COCAINE ADDICTION AND RELAPSE. 2020 8 1088 28 COCAINE DIRECTLY IMPAIRS MEMORY EXTINCTION AND ALTERS BRAIN DNA METHYLATION DYNAMICS IN HONEY BEES. DRUG ADDICTION IS A CHRONIC RELAPSING BEHAVIORAL DISORDER. THE HIGH RELAPSE RATE HAS OFTEN BEEN ATTRIBUTED TO THE PERSEVERANCE OF DRUG-ASSOCIATED MEMORIES DUE TO HIGH INCENTIVE SALIENCE OF STIMULI LEARNT UNDER THE INFLUENCE OF DRUGS. DRUG ADDICTION HAS ALSO BEEN INTERPRETED AS A MEMORY DISORDER SINCE DRUG ASSOCIATED MEMORIES ARE UNUSUALLY ENDURING AND SOME DRUGS, SUCH AS COCAINE, INTERFERE WITH NEUROEPIGENETIC MACHINERY KNOWN TO BE INVOLVED IN MEMORY PROCESSING. HERE WE USED THE HONEY BEE (AN ESTABLISHED INVERTEBRATE MODEL FOR EPIGENOMICS AND BEHAVIORAL STUDIES) TO EXAMINE WHETHER OR NOT COCAINE AFFECTS MEMORY PROCESSING INDEPENDENTLY OF ITS EFFECT ON INCENTIVE SALIENCE. USING THE PROBOSCIS EXTENSION REFLEX TRAINING PARADIGM WE FOUND THAT COCAINE STRONGLY IMPAIRS CONSOLIDATION OF EXTINCTION MEMORY. BASED ON CORRELATION BETWEEN THE OBSERVED EFFECT OF COCAINE ON LEARNING AND EXPRESSION OF EPIGENETIC PROCESSES, WE PROPOSE THAT COCAINE INTERFERES WITH MEMORY PROCESSING INDEPENDENTLY OF INCENTIVE SALIENCE BY DIRECTLY ALTERING DNA METHYLATION DYNAMICS. OUR FINDINGS EMPHASIZE THE IMPACT OF COCAINE ON MEMORY SYSTEMS, WITH RELEVANCE FOR UNDERSTANDING HOW COCAINE CAN HAVE SUCH AN ENDURING IMPACT ON BEHAVIOR. 2018 9 4846 26 OPIATE ADDICTION AND COCAINE ADDICTION: UNDERLYING MOLECULAR NEUROBIOLOGY AND GENETICS. ADDICTIVE DISEASES, INCLUDING ADDICTION TO HEROIN, PRESCRIPTION OPIOIDS, OR COCAINE, POSE MASSIVE PERSONAL AND PUBLIC HEALTH COSTS. ADDICTIONS ARE CHRONIC RELAPSING DISEASES OF THE BRAIN CAUSED BY DRUG-INDUCED DIRECT EFFECTS AND PERSISTING NEUROADAPTATIONS AT THE EPIGENETIC, MRNA, NEUROPEPTIDE, NEUROTRANSMITTER, OR PROTEIN LEVELS. THESE NEUROADAPTATIONS, WHICH CAN BE SPECIFIC TO DRUG TYPE, AND THEIR RESULTANT BEHAVIORS ARE MODIFIED BY VARIOUS INTERNAL AND EXTERNAL ENVIRONMENTAL FACTORS, INCLUDING STRESS RESPONSIVITY, ADDICT MINDSET, AND SOCIAL SETTING. SPECIFIC GENE VARIANTS, INCLUDING VARIANTS ENCODING PHARMACOLOGICAL TARGET PROTEINS OR GENES MEDIATING NEUROADAPTATIONS, ALSO MODIFY VULNERABILITY AT PARTICULAR STAGES OF ADDICTION. GREATER UNDERSTANDING OF THESE INTERACTING FACTORS THROUGH LABORATORY-BASED AND TRANSLATIONAL STUDIES HAVE THE POTENTIAL TO OPTIMIZE EARLY INTERVENTIONS FOR THE THERAPY OF CHRONIC ADDICTIVE DISEASES AND TO REDUCE THE BURDEN OF RELAPSE. HERE, WE REVIEW THE MOLECULAR NEUROBIOLOGY AND GENETICS OF OPIATE ADDICTION, INCLUDING HEROIN AND PRESCRIPTION OPIOIDS, AND COCAINE ADDICTION. 2012 10 6602 29 TWO KINDS OF TRANSCRIPTION FACTORS MEDIATE CHRONIC MORPHINE-INDUCED DECREASE IN MIR-105 IN MEDIAL PREFRONTAL CORTEX OF RATS. CHRONIC MORPHINE ADMINISTRATION ALTERS GENE EXPRESSION IN DIFFERENT BRAIN REGIONS, AN EFFECT WHICH MAY CONTRIBUTE TO PLASTIC CHANGES ASSOCIATED WITH ADDICTIVE BEHAVIOR. THIS CHANGE IN GENE EXPRESSION IS MOST POSSIBLY MEDIATED BY ADDICTIVE DRUG-INDUCED EPIGENETIC REMODELING OF GENE EXPRESSION PROGRAMS. OUR PREVIOUS STUDIES SHOWED THAT CHRONIC MORPHINE-INDUCED DECREASE OF MIR-105 IN THE MEDIAL PREFRONTAL CORTEX (MPFC) CONTRIBUTED TO CONTEXT-INDUCED RETRIEVAL OF MORPHINE WITHDRAWAL MEMORY. HOWEVER, HOW CHRONIC MORPHINE TREATMENT DECREASES MIR-105 IN THE MPFC STILL REMAINS UNKNOWN. THE PRESENT STUDY SHOWS THAT CHRONIC MORPHINE INDUCES ADDICTION-RELATED CHANGE IN MIR-105 IN THE MPFC VIA TWO KINDS OF TRANSCRIPTION FACTORS: THE FIRST TRANSCRIPTION FACTOR IS CREB ACTIVATED BY MU RECEPTORS-ERK-P90RSK SIGNALING PATHWAY AND THE SECOND TRANSCRIPTION FACTOR IS GLUCOCORTICOID RECEPTOR (GR), WHICH AS A NEGATIVE TRANSCRIPTION FACTOR, MEDIATES CHRONIC MORPHINE-INDUCED DECREASE IN MIR-105 IN THE MPFC OF RATS. 2022 11 4878 45 OVEREXPRESSION OF THE HISTONE DIMETHYLTRANSFERASE G9A IN NUCLEUS ACCUMBENS SHELL INCREASES COCAINE SELF-ADMINISTRATION, STRESS-INDUCED REINSTATEMENT, AND ANXIETY. REPEATED EXPOSURE TO COCAINE INDUCES LASTING EPIGENETIC CHANGES IN NEURONS THAT PROMOTE THE DEVELOPMENT AND PERSISTENCE OF ADDICTION. ONE EPIGENETIC ALTERATION INVOLVES REDUCTIONS IN LEVELS OF THE HISTONE DIMETHYLTRANSFERASE G9A IN NUCLEUS ACCUMBENS (NAC) AFTER CHRONIC COCAINE ADMINISTRATION. THIS REDUCTION IN G9A MAY ENHANCE COCAINE REWARD BECAUSE OVEREXPRESSING G9A IN THE NAC DECREASES COCAINE-CONDITIONED PLACE PREFERENCE. THEREFORE, WE HYPOTHESIZED THAT HSV-MEDIATED G9A OVEREXPRESSION IN THE NAC SHELL (NACSH) WOULD ATTENUATE COCAINE SELF-ADMINISTRATION (SA) AND COCAINE-SEEKING BEHAVIOR. INSTEAD, WE FOUND THAT G9A OVEREXPRESSION, AND THE RESULTING INCREASE IN HISTONE 3 LYSINE 9 DIMETHYLATION (H3K9ME2), INCREASES SENSITIVITY TO COCAINE REINFORCEMENT AND ENHANCES MOTIVATION FOR COCAINE IN SELF-ADMINISTERING MALE RATS. MOREOVER, WHEN G9A OVEREXPRESSION IS LIMITED TO THE INITIAL 15 D OF COCAINE SA TRAINING, IT PRODUCES AN ENDURING POSTEXPRESSION ENHANCEMENT IN COCAINE SA AND PROLONGED (OVER 5 WEEKS) INCREASES IN REINSTATEMENT OF COCAINE SEEKING INDUCED BY FOOT-SHOCK STRESS, BUT IN THE ABSENCE OF CONTINUED GLOBAL ELEVATIONS IN H3K9ME2. THE INCREASE IN STRESS-INDUCED REINSTATEMENT IS PARALLELED BY HEIGHTENED ANXIETY MEASURES, SUGGESTING THAT COUNTERING THE COCAINE-INDUCED DECREASES IN ENDOGENOUS G9A WITH ECTOPIC G9A OVEREXPRESSION LEADS TO LASTING ANXIOGENIC EFFECTS. FINALLY, WE FOUND AN ENDURING REDUCTION IN PHOSPHORYLATED CAMP-RESPONSE ELEMENT BINDING PROTEIN LEVELS IN THE NACSH THAT COULD ACCOUNT FOR THE INCREASED ANXIETY. THESE DATA DEMONSTRATE A NOVEL ROLE FOR G9A IN PROMOTING COMORBID COCAINE ADDICTION AND ANXIETY AND SUGGEST THAT INCREASED EPIGENETIC REPRESSION OF TRANSCRIPTION THROUGH H3K9 DURING COCAINE USE CAN HAVE LONG-LASTING AND UNEXPECTED NEGATIVE CONSEQUENCES ON BEHAVIOR.SIGNIFICANCE STATEMENT COCAINE ADDICTION IS A NEUROPSYCHIATRIC DISORDER THAT IS DETRIMENTAL TO SOCIETY AND CURRENTLY HAS NO EFFECTIVE TREATMENTS. THE DIFFICULTY IN TREATING DRUG ADDICTION IS COMPOUNDED BY THE HIGH COMORBIDITY WITH OTHER PSYCHIATRIC ILLNESSES, INCLUDING ANXIETY DISORDERS. HERE, WE DEMONSTRATE THAT G9A, AN EPIGENETIC REPRESSOR OF GENE EXPRESSION, ACTING IN THE NUCLEUS ACCUMBENS, A BRAIN REWARD REGION, IS CAPABLE OF INCREASING BOTH ADDICTION- AND ANXIETY-LIKE BEHAVIORS IN RATS. THESE FINDINGS ARE INTRIGUING BECAUSE REPEATED COCAINE EXPOSURE DECREASES G9A IN THIS REGION AND THEREBY ENHANCES EXPRESSION OF CERTAIN ADDICTION-PROMOTING GENES. HOWEVER, OUR RESULTS SUGGEST THAT COUNTERING THIS COCAINE-INDUCED DECREASE IN G9A ACTIVITY ACTUALLY EXACERBATES ADDICTION AND SENSITIVITY TO RELAPSE UNDER STRESSFUL SITUATIONS. 2018 12 69 30 A MEDIAL PREFRONTAL CORTEX-NUCLEUS ACUMENS CORTICOTROPIN-RELEASING FACTOR CIRCUITRY FOR NEUROPATHIC PAIN-INCREASED SUSCEPTIBILITY TO OPIOID REWARD. RECENT STUDIES HAVE SHOWN THAT PERSISTENT PAIN FACILITATES THE RESPONSE TO MORPHINE REWARD. HOWEVER, THE CIRCUIT MECHANISM UNDERLYING THIS PROCESS REMAINS AMBIGUOUS. IN THIS STUDY, USING CHRONIC CONSTRICTION INJURY (CCI) OF THE SCIATIC NERVE IN MICE, WE FOUND THAT PERSISTENT NEUROPATHIC PAIN REDUCED THE MINIMUM NUMBER OF MORPHINE CONDITIONING SESSIONS REQUIRED TO INDUCE CONDITIONED PLACE PREFERENCE (CPP) BEHAVIOR. THIS DOSE OF MORPHINE HAD NO EFFECT ON THE PAIN THRESHOLD. IN THE MEDIAL PREFRONTAL CORTEX (MPFC), WHICH IS INVOLVED IN BOTH PAIN AND EMOTION PROCESSING, CORTICOTROPIN-RELEASING FACTOR (CRF) EXPRESSING NEURONAL ACTIVITY WAS INCREASED IN CCI MICE. CHEMOGENETIC INHIBITION OF MPFC CRF NEURONS REVERSED CCI-INDUCED MORPHINE CPP FACILITATION. FURTHERMORE, THE NUCLEUS ACUMENS (NAC) RECEIVED MPFC CRF FUNCTIONAL PROJECTIONS THAT EXERTED EXCITATORY EFFECTS ON NAC NEURONS. OPTOGENETIC INHIBITION OF MPCF NEURONAL TERMINALS OR LOCAL INFUSION OF THE CRF RECEPTOR 1 (CRFR1) ANTAGONIST IN THE NAC RESTORED THE EFFECTS OF NEUROPATHIC PAIN ON MORPHINE-INDUCED CPP BEHAVIOR, BUT NOT IN NORMAL MICE. ON A MOLECULAR LEVEL, IN CCI MICE, CRFR1 PROTEIN EXPRESSION WAS INCREASED IN THE NAC BY A HISTONE DIMETHYLTRANSFERASE G9A-MEDIATED EPIGENETIC MECHANISM. LOCAL G9A KNOCKDOWN INCREASED THE EXPRESSION OF CRFR1 AND MIMICKED CCI-INDUCED HYPERSENSITIVITY TO ACQUIRING MORPHINE CPP. TAKEN TOGETHER, THESE FINDINGS DEMONSTRATE A PREVIOUSLY UNKNOWN AND SPECIFIC MPFC CRF ENGAGEMENT OF NAC NEURONAL CIRCUITS, THE SENSITIZATION OF WHICH FACILITATES BEHAVIORAL RESPONSES TO MORPHINE REWARD IN NEUROPATHIC PAIN STATES VIA CRFR1S. 2018 13 1677 23 DRUG ADDICTION: HYPERKATIFEIA/NEGATIVE REINFORCEMENT AS A FRAMEWORK FOR MEDICATIONS DEVELOPMENT. COMPULSIVE DRUG SEEKING THAT IS ASSOCIATED WITH ADDICTION IS HYPOTHESIZED TO FOLLOW A HEURISTIC FRAMEWORK THAT INVOLVES THREE STAGES (BINGE/INTOXICATION, WITHDRAWAL/NEGATIVE AFFECT, AND PREOCCUPATION/ANTICIPATION) AND THREE DOMAINS OF DYSFUNCTION (INCENTIVE SALIENCE/PATHOLOGIC HABITS, NEGATIVE EMOTIONAL STATES, AND EXECUTIVE FUNCTION, RESPECTIVELY) VIA CHANGES IN THE BASAL GANGLIA, EXTENDED AMYGDALA/HABENULA, AND FRONTAL CORTEX, RESPECTIVELY. THIS REVIEW FOCUSES ON NEUROCHEMICAL/NEUROCIRCUITRY DYSREGULATIONS THAT CONTRIBUTE TO HYPERKATIFEIA, DEFINED AS A GREATER INTENSITY OF NEGATIVE EMOTIONAL/MOTIVATIONAL SIGNS AND SYMPTOMS DURING WITHDRAWAL FROM DRUGS OF ABUSE IN THE WITHDRAWAL/NEGATIVE AFFECT STAGE OF THE ADDICTION CYCLE. HYPERKATIFEIA PROVIDES AN ADDITIONAL SOURCE OF MOTIVATION FOR COMPULSIVE DRUG SEEKING VIA NEGATIVE REINFORCEMENT. NEGATIVE REINFORCEMENT REFLECTS AN INCREASE IN THE PROBABILITY OF A RESPONSE TO REMOVE AN AVERSIVE STIMULUS OR DRUG SEEKING TO REMOVE HYPERKATIFEIA THAT IS AUGMENTED BY GENETIC/EPIGENETIC VULNERABILITY, ENVIRONMENTAL TRAUMA, AND PSYCHIATRIC COMORBIDITY. NEUROBIOLOGICAL TARGETS FOR HYPERKATIFEIA IN ADDICTION INVOLVE NEUROCIRCUITRY OF THE EXTENDED AMYGDALA AND ITS CONNECTIONS VIA WITHIN-SYSTEM NEUROADAPTATIONS IN DOPAMINE, ENKEPHALIN/ENDORPHIN OPIOID PEPTIDE, AND GAMMA-AMINOBUTYRIC ACID/GLUTAMATE SYSTEMS AND BETWEEN-SYSTEM NEUROADAPTATIONS IN PROSTRESS CORTICOTROPIN-RELEASING FACTOR, NOREPINEPHRINE, GLUCOCORTICOID, DYNORPHIN, HYPOCRETIN, AND NEUROIMMUNE SYSTEMS AND ANTISTRESS NEUROPEPTIDE Y, NOCICEPTIN, ENDOCANNABINOID, AND OXYTOCIN SYSTEMS. SUCH NEUROCHEMICAL/NEUROCIRCUITRY DYSREGULATIONS ARE HYPOTHESIZED TO MEDIATE A NEGATIVE HEDONIC SET POINT THAT GRADUALLY GAINS ALLOSTATIC LOAD AND SHIFTS FROM A HOMEOSTATIC HEDONIC STATE TO AN ALLOSTATIC HEDONIC STATE. BASED ON PRECLINICAL STUDIES AND TRANSLATIONAL STUDIES TO DATE, MEDICATIONS AND BEHAVIORAL THERAPIES THAT RESET BRAIN STRESS, ANTISTRESS, AND EMOTIONAL PAIN SYSTEMS AND RETURN THEM TO HOMEOSTASIS WOULD BE PROMISING NEW TARGETS FOR MEDICATION DEVELOPMENT. SIGNIFICANCE STATEMENT: THE FOCUS OF THIS REVIEW IS ON NEUROCHEMICAL/NEUROCIRCUITRY DYSREGULATIONS THAT CONTRIBUTE TO HYPERKATIFEIA, DEFINED AS A GREATER INTENSITY OF NEGATIVE EMOTIONAL/MOTIVATIONAL SIGNS AND SYMPTOMS DURING WITHDRAWAL FROM DRUGS OF ABUSE IN THE WITHDRAWAL/NEGATIVE AFFECT STAGE OF THE DRUG ADDICTION CYCLE AND A DRIVING FORCE FOR NEGATIVE REINFORCEMENT IN ADDICTION. MEDICATIONS AND BEHAVIORAL THERAPIES THAT REVERSE HYPERKATIFEIA BY RESETTING BRAIN STRESS, ANTISTRESS, AND EMOTIONAL PAIN SYSTEMS AND RETURNING THEM TO HOMEOSTASIS WOULD BE PROMISING NEW TARGETS FOR MEDICATION DEVELOPMENT. 2021 14 4935 30 PATERNAL COCAINE TAKING ELICITS EPIGENETIC REMODELING AND MEMORY DEFICITS IN MALE PROGENY. PATERNAL ENVIRONMENTAL PERTURBATIONS INCLUDING EXPOSURE TO DRUGS OF ABUSE CAN PRODUCE PROFOUND EFFECTS ON THE PHYSIOLOGY AND BEHAVIOR OF OFFSPRING VIA EPIGENETIC MODIFICATIONS. HERE WE SHOW THAT ADULT DRUG-NAIVE MALE OFFSPRING OF COCAINE-EXPOSED SIRES HAVE MEMORY FORMATION DEFICITS AND ASSOCIATED REDUCTIONS IN NMDA RECEPTOR-MEDIATED HIPPOCAMPAL SYNAPTIC PLASTICITY. REDUCED LEVELS OF THE ENDOGENOUS NMDA RECEPTOR CO-AGONIST D-SERINE WERE ACCOMPANIED BY INCREASED EXPRESSION OF THE D-SERINE DEGRADING ENZYME D-AMINO ACID OXIDASE (DAO1) IN THE HIPPOCAMPUS OF COCAINE-SIRED MALE PROGENY. INCREASED DAO1 TRANSCRIPTION WAS ASSOCIATED WITH ENRICHMENT OF PERMISSIVE EPIGENETIC MARKS ON HISTONE PROTEINS IN THE HIPPOCAMPUS OF MALE COCAINE-SIRED PROGENY, SOME OF WHICH WERE ENHANCED NEAR THE DAO1 LOCUS. FINALLY, HIPPOCAMPAL ADMINISTRATION OF D-SERINE REVERSED BOTH THE MEMORY FORMATION AND SYNAPTIC PLASTICITY DEFICITS. COLLECTIVELY, THESE RESULTS DEMONSTRATE THAT PATERNAL COCAINE EXPOSURE PRODUCES EPIGENETIC REMODELING IN THE HIPPOCAMPUS LEADING TO NMDA RECEPTOR-DEPENDENT MEMORY FORMATION AND SYNAPTIC PLASTICITY IMPAIRMENTS ONLY IN MALE PROGENY, WHICH HAS SIGNIFICANT IMPLICATIONS FOR THE MALE DESCENDANTS OF CHRONIC COCAINE USERS. 2017 15 2513 29 EPIGENETICS AND PSYCHOSTIMULANT ADDICTION. CHRONIC DRUG EXPOSURE ALTERS GENE EXPRESSION IN THE BRAIN AND PRODUCES LONG-TERM CHANGES IN NEURAL NETWORKS THAT UNDERLIE COMPULSIVE DRUG TAKING AND SEEKING. EXACTLY HOW DRUG-INDUCED CHANGES IN SYNAPTIC PLASTICITY AND SUBSEQUENT GENE EXPRESSION ARE TRANSLATED INTO PERSISTENT NEUROADAPTATIONS REMAINS UNCLEAR. EMERGING EVIDENCE SUGGESTS THAT COMPLEX DRUG-INDUCED NEUROADAPTATIONS IN THE BRAIN ARE MEDIATED BY HIGHLY SYNCHRONIZED AND DYNAMIC PATTERNS OF GENE REGULATION. RECENTLY, IT HAS BECOME CLEAR THAT EPIGENETIC MECHANISMS CONTRIBUTE TO DRUG-INDUCED STRUCTURAL, SYNAPTIC, AND BEHAVIORAL PLASTICITY BY REGULATING EXPRESSION OF GENE NETWORKS. HERE WE REVIEW HOW ALTERATIONS IN HISTONE MODIFICATIONS, DNA METHYLATION, AND MICRORNAS REGULATE GENE EXPRESSION AND CONTRIBUTE TO PSYCHOSTIMULANT ADDICTION WITH A FOCUS ON THE EPIGENETIC MECHANISMS THAT REGULATE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) EXPRESSION FOLLOWING CHRONIC COCAINE EXPOSURE. IDENTIFYING EPIGENETIC SIGNATURES THAT DEFINE PSYCHOSTIMULANT ADDICTION MAY LEAD TO NOVEL, EFFICACIOUS TREATMENTS FOR DRUG CRAVING AND RELAPSE. 2013 16 3314 42 HIPPOCAMPAL CANNABINOID 1 RECEPTORS ARE MODULATED FOLLOWING COCAINE SELF-ADMINISTRATION IN MALE RATS. COCAINE ADDICTION IS A COMPLEX PATHOLOGY INDUCING LONG-TERM NEUROPLASTIC CHANGES THAT, IN TURN, CONTRIBUTE TO MALADAPTIVE BEHAVIORS. THIS BEHAVIORAL DYSREGULATION IS ASSOCIATED WITH TRANSCRIPTIONAL REPROGRAMMING IN BRAIN REWARD CIRCUITRY, ALTHOUGH THE MECHANISMS UNDERLYING THIS MODULATION REMAIN POORLY UNDERSTOOD. THE ENDOGENOUS CANNABINOID SYSTEM MAY PLAY A ROLE IN THIS PROCESS IN THAT CANNABINOID MECHANISMS MODULATE DRUG REWARD AND CONTRIBUTE TO COCAINE-INDUCED NEURAL ADAPTATIONS. IN THIS STUDY, WE INVESTIGATED WHETHER COCAINE SELF-ADMINISTRATION INDUCES LONG-TERM ADAPTATIONS, INCLUDING TRANSCRIPTIONAL MODIFICATIONS AND ASSOCIATED EPIGENETIC PROCESSES. WE FIRST EXAMINED ENDOCANNABINOID GENE EXPRESSION IN REWARD-RELATED BRAIN REGIONS OF THE RAT FOLLOWING SELF-ADMINISTERED (0.33 MG/KG INTRAVENOUS, FR1, 10 DAYS) COCAINE INJECTIONS. INTERESTINGLY, WE FOUND INCREASED CNR1 EXPRESSION IN SEVERAL STRUCTURES, INCLUDING PREFRONTAL CORTEX, NUCLEUS ACCUMBENS, DORSAL STRIATUM, HIPPOCAMPUS, HABENULA, AMYGDALA, LATERAL HYPOTHALAMUS, VENTRAL TEGMENTAL AREA, AND ROSTROMEDIAL TEGMENTAL NUCLEUS, WITH MOST PRONOUNCED EFFECTS IN THE HIPPOCAMPUS. ENDOCANNABINOID LEVELS, MEASURED BY MASS SPECTROMETRY, WERE ALSO ALTERED IN THIS STRUCTURE. CHROMATIN IMMUNOPRECIPITATION FOLLOWED BY QPCR IN THE HIPPOCAMPUS REVEALED THAT TWO ACTIVATING HISTONE MARKS, H3K4ME3 AND H3K27AC, WERE ENRICHED AT SPECIFIC ENDOCANNABINOID GENES FOLLOWING COCAINE INTAKE. TARGETING CB1 RECEPTORS USING CHROMOSOME CONFORMATION CAPTURE, WE HIGHLIGHTED SPATIAL CHROMATIN RE-ORGANIZATION IN THE HIPPOCAMPUS, AS WELL AS IN THE NUCLEUS ACCUMBENS, SUGGESTING THAT DESTABILIZATION OF THE CHROMATIN MAY CONTRIBUTE TO NEURONAL RESPONSES TO COCAINE. OVERALL, OUR RESULTS HIGHLIGHT A KEY ROLE FOR THE HIPPOCAMPUS IN COCAINE-INDUCED PLASTICITY AND BROADEN THE UNDERSTANDING OF NEURONAL ALTERATIONS ASSOCIATED WITH ENDOCANNABINOID SIGNALING. THE LATTER SUGGESTS THAT EPIGENETIC MODIFICATIONS CONTRIBUTE TO MALADAPTIVE BEHAVIORS ASSOCIATED WITH CHRONIC DRUG USE. 2022 17 4418 27 MOLECULAR AND EPIGENETIC ASPECTS OF OPIOID RECEPTORS IN DRUG ADDICTION AND PAIN MANAGEMENT IN SPORT. OPIOIDS ARE SUBSTANCES DERIVED FROM OPIUM (NATURAL OPIOIDS). IN ITS RAW STATE, OPIUM IS A GUMMY LATEX EXTRACTED FROM PAPAVER SOMNIFERUM. THE USE OF OPIOIDS AND THEIR NEGATIVE HEALTH CONSEQUENCES AMONG PEOPLE WHO USE DRUGS HAVE BEEN STUDIED. TODAY, OPIOIDS ARE STILL THE MOST COMMONLY USED AND EFFECTIVE ANALGESIC TREATMENTS FOR SEVERE PAIN, BUT THEIR USE AND ABUSE CAUSES DETRIMENTAL SIDE EFFECTS FOR HEALTH, INCLUDING ADDICTION, THUS IMPACTING THE USER'S QUALITY OF LIFE AND CAUSING OVERDOSE. THE MESOCORTICOLIMBIC DOPAMINERGIC CIRCUITRY REPRESENTS THE BRAIN CIRCUIT MEDIATING BOTH NATURAL REWARDS AND THE REWARDING ASPECTS OF NEARLY ALL DRUGS OF ABUSE, INCLUDING OPIOIDS. HENCE, UNDERSTANDING HOW OPIOIDS AFFECT THE FUNCTION OF DOPAMINERGIC CIRCUITRY MAY BE USEFUL FOR BETTER KNOWLEDGE OF THE PROCESS AND TO DEVELOP EFFECTIVE THERAPEUTIC STRATEGIES IN ADDICTION. THE AIM OF THIS REVIEW WAS TO SUMMARIZE THE MAIN FEATURES OF OPIOIDS AND OPIOID RECEPTORS AND FOCUS ON THE MOLECULAR AND UPCOMING EPIGENETIC MECHANISMS LEADING TO OPIOID ADDICTION. SINCE SYNTHETIC OPIOIDS CAN BE EFFECTIVE FOR PAIN MANAGEMENT, THEIR ABILITY TO INDUCE ADDICTION IN ATHLETES, WITH THE RISK OF INCURRING DOPING, IS ALSO DISCUSSED. 2023 18 1783 28 EFFECT OF AGOMELATINE ON MEMORY DEFICITS AND HIPPOCAMPAL GENE EXPRESSION INDUCED BY CHRONIC SOCIAL DEFEAT STRESS IN MICE. CHRONIC STRESS IS KNOWN TO INDUCE NOT ONLY ANXIETY AND DEPRESSIVE-LIKE PHENOTYPES IN MICE BUT ALSO COGNITIVE IMPAIRMENTS, FOR WHICH THE ACTION OF CLASSICAL ANTIDEPRESSANT COMPOUNDS REMAINS UNSATISFACTORY. IN THIS CONTEXT, WE INVESTIGATED THE EFFECTS OF CHRONIC SOCIAL DEFEAT STRESS (CSDS) ON ANXIETY-, SOCIAL- AND COGNITIVE-RELATED BEHAVIORS, AS WELL AS HIPPOCAMPAL BDNF, SYNAPTIC PLASTICITY MARKERS (PSD-95, SYNAPTOPHYSIN, SPINOPHILIN, SYNAPSIN I AND MAP-2), AND EPIGENETIC MODIFYING ENZYMES (MYST2, HDAC2, HDAC6, MLL3, KDM5B, DNMT3B, GADD45B) GENE EXPRESSION IN C57BL/6J MICE. CSDS FOR 10 DAYS PROVOKED LONG-LASTING ANXIOUS-LIKE PHENOTYPE IN THE OPEN FIELD AND EPISODIC MEMORY DEFICITS IN THE NOVEL OBJECT RECOGNITION TEST. WHILE TOTAL BDNF MRNA LEVEL WAS UNCHANGED, BDNF EXON IV, MAP-2, HDAC2, HDAC6 AND MLL3 GENE EXPRESSION WAS SIGNIFICANTLY DECREASED IN THE CSDS MOUSE HIPPOCAMPUS. IN CSDS MICE TREATED 3 WEEKS WITH 50 MG/KG/D AGOMELATINE, AN ANTIDEPRESSANT WITH MELATONERGIC RECEPTOR AGONIST AND 5-HT(2C) RECEPTOR ANTAGONIST PROPERTIES, THE ANXIOUS-LIKE PHENOTYPE WAS NOT REVERSED, BUT THE TREATMENT SUCCESSFULLY PREVENTED THE COGNITIVE IMPAIRMENTS AND HIPPOCAMPAL GENE EXPRESSION MODIFICATIONS. ALTOGETHER, THESE DATA EVIDENCED THAT, IN MICE, AGOMELATINE WAS EFFECTIVE IN ALLEVIATING STRESS-INDUCED ALTERED COGNITIVE FUNCTIONS, POSSIBLY THROUGH A MECHANISM INVOLVING BDNF SIGNALING, SYNAPTIC PLASTICITY AND EPIGENETIC REMODELING. 2017 19 1821 30 EFFECTS OF CHRONIC SOCIAL DEFEAT ON BEHAVIORAL AND NEURAL CORRELATES OF SOCIALITY: VASOPRESSIN, OXYTOCIN AND THE VASOPRESSINERGIC V1B RECEPTOR. CHRONIC SOCIAL STRESS IN RODENTS PRODUCES BEHAVIORAL AND NEUROENDOCRINE PATTERNS ANALOGOUS TO SYMPTOMS ASSOCIATED WITH PSYCHOPATHOLOGIES IN HUMANS. CHRONIC SOCIAL DEFEAT IN MICE HAS BEEN USED TO STUDY THE GENETIC AND EPIGENETIC PRECURSORS OF STRESS-RELATED SOCIAL DISORDERS. THE NEUROPEPTIDES ARGININE VASOPRESSIN (AVP) AND OXYTOCIN (OT) ARE RELEASED IN CENTRAL TARGETS TO MODULATE ANTI- AND PRO-SOCIAL BEHAVIORS, RESPECTIVELY. AVP BINDS TO V1A AND V1B RECEPTORS (V1BRS) IN DISCRETE BRAIN REGIONS RELATED TO ANXIETY, DEPRESSION AND AFFILIATIVE BEHAVIORS. RECENT EVIDENCE SUGGESTS THAT V1BRS ARE INVOLVED IN STRESS AND ANXIETY AND MAY BE AN ATTRACTIVE TARGET FOR THE TREATMENT OF ASSOCIATED DISORDERS. IN THE PRESENT SERIES OF EXPERIMENTS, WE AIMED TO EVALUATE THE EFFECTS OF CHRONIC SOCIAL DEFEAT STRESS ON: 1) ANXIETY-RELATED BEHAVIORS IN A SOCIAL INVESTIGATION PARADIGM AND THEIR POTENTIAL MODULATION BY AN ACUTE DOSE OF SSR149415, A V1BR ANTAGONIST; 2) AVP AND FOS PROTEIN LEVELS IN THE PARAVENTRICULAR NUCLEUS OF THE HYPOTHALAMUS (PVN) AND; 3) AVP- AND OT-RECEPTOR (OTR) MRNA LEVELS IN BRAIN REGIONS ASSOCIATED WITH SOCIALITY. WHEN COMPARED TO UNDEFEATED ANIMALS, SOCIALLY DEFEATED MICE EXHIBITED AN ANXIOGENIC BEHAVIORAL PROFILE TOWARDS A NOVEL MALE CONSPECIFIC, WITH SSR149415 PARTLY ATTENUATING THESE EFFECTS. HISTOCHEMISTRY USING IMMUNOFLUORESCENCE SHOWED DEFEAT PRODUCED SIGNIFICANT ELEVATIONS OF FOS AND DOUBLE LABELING OF AVP AND FOS PROTEINS IN THE PARAVENTRICULAR NUCLEUS OF THE HYPOTHALAMUS (PVN). SSR149415 ATTENUATED THE EFFECTS OF DEFEAT ON FOS AND AVP/FOS DOUBLE LABELING, CONSISTENT WITH AN ANXIOLYTIC EFFECT. DEFEATED MICE SHOWED ELEVATED LEVELS OF OTR MRNA LEVELS IN THE LATERAL SEPTUM (LS) IN ADDITION TO INCREASED V1BR AND OTR MRNA IN THE MEDIAL AMYGDALA (MEA). WE SUGGEST THE INVOLVEMENT OF V1BRS AND OTRS IN A CIRCUIT INVOLVING THE PVN, MEA AND LS IN THE EFFECTS OF DEFEAT ON SOCIALITY. SSR149415 ATTENUATED ANXIOGENESIS IN THE SOCIAL INVESTIGATION MODEL AND BOTH FOS AND AVP/FOS LABELING, SUGGESTING V1BRS ARE AN ATTRACTIVE TARGET FOR THE TREATMENT OF ANXIETY IN GENERAL AND DISORDERS OF SOCIALITY IN PARTICULAR. 2011 20 2773 31 EXTRACELLULAR SIGNAL-REGULATED PROTEIN KINASES 1 AND 2 ACTIVATION BY ADDICTIVE DRUGS: A SIGNAL TOWARD PATHOLOGICAL ADAPTATION. ADDICTION IS A CHRONIC AND RELAPSING PSYCHIATRIC DISORDER THAT IS THOUGHT TO OCCUR IN VULNERABLE INDIVIDUALS. SYNAPTIC PLASTICITY EVOKED BY DRUGS OF ABUSE IN THE SO-CALLED NEURONAL CIRCUITS OF REWARD HAS BEEN PROPOSED TO UNDERLIE BEHAVIORAL ADAPTATIONS THAT CHARACTERIZE ADDICTION. BY INCREASING DOPAMINE IN THE STRIATUM, ADDICTIVE DRUGS ALTER THE BALANCE OF DOPAMINE AND GLUTAMATE SIGNALS CONVERGING ONTO STRIATAL MEDIUM-SIZED SPINY NEURONS (MSNS) AND ACTIVATE INTRACELLULAR EVENTS INVOLVED IN LONG-TERM BEHAVIORAL ALTERATIONS. OUR LABORATORY CONTRIBUTED TO THE IDENTIFICATION OF SALIENT MOLECULAR CHANGES INDUCED BY ADMINISTRATION OF ADDICTIVE DRUGS TO RODENTS. WE PIONEERED THE OBSERVATION THAT A COMMON FEATURE OF ADDICTIVE DRUGS IS TO ACTIVATE, BY A DOUBLE TYROSINE/THREONINE PHOSPHORYLATION, THE EXTRACELLULAR SIGNAL-REGULATED KINASES 1 AND 2 (ERK1/2) IN THE STRIATUM, WHICH CONTROL A PLETHORA OF SUBSTRATES, SOME OF THEM BEING CRITICALLY INVOLVED IN COCAINE-MEDIATED MOLECULAR AND BEHAVIORAL ADAPTATIONS. HEREIN, WE REVIEW HOW THE INTERPLAY BETWEEN DOPAMINE AND GLUTAMATE SIGNALING CONTROLS COCAINE-INDUCED ERK1/2 ACTIVATION IN MSNS. WE EMPHASIZE THE KEY ROLE OF N-METHYL-D-ASPARTATE RECEPTOR POTENTIATION BY D1 RECEPTOR TO TRIGGER ERK1/2 ACTIVATION AND ITS SUBSEQUENT NUCLEAR TRANSLOCATION WHERE IT MODULATES BOTH EPIGENETIC AND GENETIC PROCESSES ENGAGED BY COCAINE. WE DISCUSS HOW COCAINE-INDUCED LONG-TERM SYNAPTIC AND STRUCTURAL PLASTICITY OF MSNS, AS WELL AS BEHAVIORAL ADAPTATIONS, ARE INFLUENCED BY ERK1/2-CONTROLLED TARGETS. WE CONCLUDE THAT A BETTER KNOWLEDGE OF MOLECULAR MECHANISMS UNDERLYING ERK1/2 ACTIVATION BY DRUGS OF ABUSE AND/OR ITS ROLE IN LONG-TERM NEURONAL PLASTICITY IN THE STRIATUM MAY PROVIDE A NEW ROUTE FOR THERAPEUTIC TREATMENT IN ADDICTION. 2014