1 6477 131 TOLUENE IMPAIRS LEARNING AND MEMORY, HAS ANTINOCICEPTIVE EFFECTS, AND MODIFIES HISTONE ACETYLATION IN THE DENTATE GYRUS OF ADOLESCENT AND ADULT RATS. TOLUENE MISUSE USUALLY INITIATES AT AN EARLY AGE WHEN THE CENTRAL NERVOUS SYSTEM IS STILL IMMATURE, CAUSING DELETERIOUS EFFECTS SUCH AS COGNITIVE IMPAIRMENT. EPIGENETIC REGULATORY MECHANISMS HAVE BEEN PROPOSED TO EXPLAIN LONG-TERM CHANGES INVOLVED NOT ONLY IN MEMORY, BUT ALSO IN TOLUENE'S ACTIONS. THE AIM OF THIS STUDY WAS TO EVALUATE THE EFFECTS OF ACUTE AND CHRONIC TOLUENE EXPOSURE ON LEARNING, MEMORY AND HISTONE ACETYLATION IN THE RAT HIPPOCAMPUS DURING TWO STAGES OF LIFE: ADOLESCENCE AND YOUNG ADULTHOOD. BECAUSE THE MEMORY TESTS USED IN THIS WORK INVOLVED OBJECT EXPLORATION AND THE PERCEPTION OF A NOXIOUS STIMULUS, GENERAL ACTIVITY AND NOCICEPTION TESTS WERE ALSO CONDUCTED. ACUTE AND CHRONIC TOLUENE INHALATION IMPAIRED LEARNING, SHORT-TERM AND LONG-TERM MEMORY IN AN OBJECT-RECOGNITION TEST AND IN AN INHIBITORY AVOIDANCE TASK IN BOTH GROUPS OF AGE. THIS EFFECT WAS CONCENTRATION-DEPENDENT AND OCCURRED EVEN AT LOW TOLUENE CONCENTRATIONS (1000, 2000 PPM) THAT WERE OTHERWISE NON-EFFECTIVE. ACUTE TOLUENE INHALATION PRODUCED ANTINOCICEPTION, AND TOLERANCE TO THIS EFFECT DEVELOPED AFTER CHRONIC EXPOSURE. HISTONE ACETYLATION IN THE DENTATE GYRUS SHOWED DIFFERENCES DEPENDING ON THE HISTONE, TREATMENT AND AGE: A SINGLE TOLUENE EXPOSURE INCREASED H4 ACETYLATION IN ADOLESCENTS AND YOUNG ADULT RATS, WHEREAS CHRONIC EXPOSURE DECREASED H3 ACETYLATION, BUT ONLY IN ADULTS. IN CONCLUSION, THIS WORK PROVIDES EVIDENCE OF TOLUENE-INDUCED IMPAIRMENT ON LEARNING, SHORT- AND LONG-TERM MEMORY IN ADOLESCENT AND YOUNG ADULT RATS, AND SHOWS THAT EVEN A SINGLE TOLUENE EXPOSURE CAN INDUCE EPIGENETIC MODIFICATIONS IN THE RAT HIPPOCAMPUS. 2012 2 1818 33 EFFECTS OF CHRONIC METHAMPHETAMINE EXPOSURE ON REWARDING BEHAVIOR AND NEURODEGENERATION MARKERS IN ADULT MICE. RECREATIONAL AND MEDICAL USE OF STIMULANTS AMONG YOUNG ADULTS HAVE GAINED POPULARITY IN THE UNITED STATES OVER THE LAST DECADE AND THEIR USE MAY INCREASE VULNERABILITY TO BRAIN BIOCHEMICAL CHANGES AND ADDICTIVE BEHAVIORS. THE LONG-TERM EFFECTS OF CHRONIC STIMULANT EXPOSURE IN LATER ADULTHOOD HAVE NOT BEEN FULLY ELUCIDATED.OUR STUDY INVESTIGATED WHETHER CHRONIC EXPOSURE TO METHAMPHETAMINE (METH), AT A DOSE DESIGNED TO EMULATE HUMAN THERAPEUTIC DOSING FOR ADHD, WOULD PROMOTE BIOCHEMICAL ALTERATIONS AND AFFECT SENSITIVITY TO THE REWARDING EFFECTS OF SUBSEQUENT METH DOSING.GROUPS OF 3.5-MONTH-OLD MALE AND FEMALE C57BL/6J MICE WERE ADMINISTERED NON-CONTINGENT INTRAPERITONEAL INJECTIONS OF EITHER SALINE OR METH (1.4 MG/KG) TWICE A DAY FOR 1 MONTH (5 DAYS/WEEK). METH (0.5 MG/KG)-INDUCED CONDITIONED PLACE PREFERENCE (CPP) WAS TESTED IN MICE TO DETERMINE THE EFFECTS OF PREVIOUS METH EXPOSURE ON REWARD-RELATED BEHAVIOR. MICE WERE RANDOMLY ASSIGNED TO EXPERIMENT I (MALES AND FEMALES) OR EXPERIMENT II (FEMALES ONLY) IN WHICH CPP TESTING WAS RESPECTIVELY PERFORMED EITHER 0.5 OR 5 MONTHS AFTER THE END OF METH INJECTIONS, AT ~5 OR 10 MONTHS OLD RESPECTIVELY. THE MIDBRAIN AND STRIATUM, REGIONS INVOLVED IN REWARD CIRCUIT, WERE ASSESSED FOR MARKERS ASSOCIATED WITH NEUROTOXICITY, DOPAMINERGIC FUNCTION, NEUROINFLAMMATION AND EPIGENETIC CHANGES AFTER BEHAVIORAL TESTING.PREVIOUS EXPOSURE TO CHRONIC METH DID NOT HAVE SIGNIFICANT SHORT-TERM EFFECTS ON CPP RESPONSE BUT LED TO A DECREASED CPP RESPONSE IN 10-MONTH-OLD FEMALES. PREVIOUS EXPOSURE TO METH INDUCED SOME SHORT-TERM CHANGES TO BIOCHEMICAL MARKERS MEASURED IN A BRAIN REGION AND SEX-DEPENDENT MANNER, WHILE LONG-TERM CHANGES WERE ONLY OBSERVED WITH GFAP AND KDM5C.IN CONCLUSION, OUR DATA SUGGEST SEX- AND POST-EXPOSURE DURATION-DEPENDENT OUTCOMES AND WARRANT FURTHER EXPLORATION OF THE LONG-TERM NEUROBEHAVIORAL CONSEQUENCES OF PSYCHOSTIMULANT USE IN BOTH SEXES. 2023 3 4860 25 OREXIN SIGNALING MEDIATES THE ANTIDEPRESSANT-LIKE EFFECT OF CALORIE RESTRICTION. DURING PERIODS OF REDUCED FOOD AVAILABILITY, ANIMALS MUST RESPOND WITH BEHAVIORAL ADAPTATIONS THAT PROMOTE SURVIVAL. DESPITE THE FACT THAT MANY PSYCHIATRIC SYNDROMES INCLUDE DISORDERED EATING PATTERNS AS A COMPONENT OF THE ILLNESS, LITTLE IS KNOWN ABOUT THE NEUROBIOLOGY UNDERLYING BEHAVIORAL CHANGES INDUCED BY SHORT-TERM CALORIE RESTRICTION. PRESENTLY, WE DEMONSTRATE THAT 10 D OF CALORIE RESTRICTION, CORRESPONDING TO A 20-25% WEIGHT LOSS, CAUSES A MARKED ANTIDEPRESSANT-LIKE RESPONSE IN TWO RODENT MODELS OF DEPRESSION AND THAT THIS RESPONSE IS DEPENDENT ON THE HYPOTHALAMIC NEUROPEPTIDE OREXIN (HYPOCRETIN). WILD-TYPE MICE, BUT NOT MICE LACKING OREXIN, SHOW LONGER LATENCY TO IMMOBILITY AND LESS TOTAL IMMOBILITY IN THE FORCED SWIM TEST AFTER CALORIE RESTRICTION. IN THE SOCIAL DEFEAT MODEL OF CHRONIC STRESS, CALORIE RESTRICTION REVERSES THE BEHAVIORAL DEFICITS SEEN IN WILD-TYPE MICE BUT NOT IN OREXIN KNOCK-OUT MICE. ADDITIONALLY, CHRONIC SOCIAL DEFEAT STRESS INDUCES A PROLONGED REDUCTION IN THE EXPRESSION OF PREPRO-OREXIN MRNA VIA EPIGENETIC MODIFICATION OF THE OREXIN GENE PROMOTER, WHEREAS CALORIE RESTRICTION ENHANCES THE ACTIVATION OF OREXIN CELLS AFTER SOCIAL DEFEAT. TOGETHER, THESE DATA INDICATE THAT OREXIN PLAYS AN ESSENTIAL ROLE IN MEDIATING REDUCED DEPRESSION-LIKE SYMPTOMS INDUCED BY CALORIE RESTRICTION. 2008 4 1177 25 CONTROL OF BREATHING AND THE CIRCULATION IN HIGH-ALTITUDE MAMMALS AND BIRDS. HYPOXIA IS AN UNREMITTING STRESSOR AT HIGH ALTITUDES THAT PLACES A PREMIUM ON OXYGEN TRANSPORT BY THE RESPIRATORY AND CARDIOVASCULAR SYSTEMS. PHENOTYPIC PLASTICITY AND GENOTYPIC ADAPTATION AT VARIOUS STEPS IN THE O2 CASCADE COULD HELP OFFSET THE EFFECTS OF HYPOXIA ON CELLULAR O2 SUPPLY IN HIGH-ALTITUDE NATIVES. IN THIS REVIEW, WE WILL DISCUSS THE UNIQUE MECHANISMS BY WHICH VENTILATION, CARDIAC OUTPUT, AND BLOOD FLOW ARE CONTROLLED IN HIGH-ALTITUDE MAMMALS AND BIRDS. ACCLIMATIZATION TO HIGH ALTITUDES LEADS TO SOME CHANGES IN RESPIRATORY AND CARDIOVASCULAR CONTROL THAT INCREASE O2 TRANSPORT IN HYPOXIA (E.G., VENTILATORY ACCLIMATIZATION TO HYPOXIA). HOWEVER, ACCLIMATIZATION OR DEVELOPMENT IN HYPOXIA CAN ALSO MODIFY CARDIORESPIRATORY CONTROL IN WAYS THAT ARE MALADAPTIVE FOR O2 TRANSPORT. HYPOXIA RESPONSES THAT AROSE AS SHORT-TERM SOLUTIONS TO O2 DEPRIVATION (E.G., PERIPHERAL VASOCONSTRICTION) OR REGIONAL VARIATION IN O2 LEVELS IN THE LUNGS (I.E., HYPOXIC PULMONARY VASOCONSTRICTION) ARE DETRIMENTAL AT IN CHRONIC HIGH-ALTITUDE HYPOXIA. EVOLVED CHANGES IN CARDIORESPIRATORY CONTROL HAVE ARISEN IN MANY HIGH-ALTITUDE TAXA, INCLUDING INCREASES IN EFFECTIVE VENTILATION, ATTENUATION OF HYPOXIC PULMONARY VASOCONSTRICTION, AND CHANGES IN CATECHOLAMINE SENSITIVITY OF THE HEART AND SYSTEMIC VASCULATURE. PARALLEL EVOLUTION OF SOME OF THESE CHANGES IN INDEPENDENT HIGHLAND LINEAGES SUPPORTS THEIR ADAPTIVE SIGNIFICANCE. MUCH LESS IS KNOWN ABOUT THE GENOMIC BASES AND POTENTIAL INTERACTIVE EFFECTS OF ADAPTATION, ACCLIMATIZATION, DEVELOPMENTAL PLASTICITY, AND TRANS-GENERATIONAL EPIGENETIC TRANSFER ON CARDIORESPIRATORY CONTROL. FUTURE WORK TO UNDERSTAND THESE VARIOUS INFLUENCES ON BREATHING AND CIRCULATION IN HIGH-ALTITUDE NATIVES WILL HELP ELUCIDATE HOW COMPLEX PHYSIOLOGICAL SYSTEMS CAN BE PUSHED TO THEIR LIMITS TO MAINTAIN CELLULAR FUNCTION IN HYPOXIA. 2015 5 2772 37 EXTRACELLULAR ATP AND NEURODEGENERATION. ATP IS A POTENT SIGNALING MOLECULE ABUNDANTLY PRESENT IN THE CNS. IT ELICITS A WIDE ARRAY OF PHYSIOLOGICAL EFFECTS AND IS REGARDED AS THE PHYLOGENETICALLY MOST ANCIENT EPIGENETIC FACTOR PLAYING CRUCIAL BIOLOGICAL ROLES IN SEVERAL DIFFERENT TISSUES. THESE CAN RANGE FROM NEUROTRANSMISSION, SMOOTH MUSCLE CONTRACTION, CHEMOSENSORY SIGNALING, SECRETION AND VASODILATATION, TO MORE COMPLEX PHENOMENA SUCH AS IMMUNE RESPONSES, PAIN, MALE REPRODUCTION, FERTILIZATION AND EMBRYONIC DEVELOPMENT. ATP IS RELEASED INTO THE EXTRACELLULAR SPACE EITHER EXOCYTOTICALLY OR FROM DAMAGED AND DYING CELLS. IT IS OFTEN CO-RELEASED WITH OTHER NEUROTRANSMITTERS AND IT CAN INTERACT WITH GROWTH FACTORS AT BOTH RECEPTOR- AND/OR SIGNAL TRANSDUCTION-LEVEL. ONCE IN THE EXTRACELLULAR ENVIRONMENT, ATP BINDS TO SPECIFIC RECEPTORS TERMED P2. BASED ON PHARMACOLOGICAL PROFILES, ON SELECTIVITY OF COUPLING TO SECOND-MESSENGER PATHWAYS AND ON MOLECULAR CLONING, TWO MAIN SUBCLASSES WITH MULTIPLE SUBTYPES HAVE BEEN DISTINGUISHED. THEY ARE P2X, I.E. FAST CATION-SELECTIVE RECEPTOR CHANNELS (NA+, K+, CA2+), POSSESSING LOW AFFINITY FOR ATP AND RESPONSIBLE FOR FAST EXCITATORY NEUROTRANSMISSION, AND P2Y, I.E. SLOW G PROTEIN-COUPLED METABOTROPIC RECEPTORS, POSSESSING HIGHER AFFINITY FOR THE LIGAND. IN THE NERVOUS SYSTEM, THEY ARE BROADLY EXPRESSED IN BOTH NEURONS AND GLIAL CELLS AND CAN MEDIATE DUAL EFFECTS: SHORT-TERM SUCH AS NEUROTRANSMISSION, AND LONG-TERM SUCH AS TROPHIC ACTIONS. SINCE MASSIVE EXTRACELLULAR RELEASE OF ATP OFTEN OCCURS AFTER METABOLIC STRESS, BRAIN ISCHEMIA AND TRAUMA, PURINERGIC MECHANISMS ARE ALSO CORRELATED TO AND INVOLVED IN THE ETIOPATHOLOGY OF MANY NEURODEGENERATIVE CONDITIONS. FURTHERMORE, EXTRACELLULAR ATP PER SE IS TOXIC FOR PRIMARY NEURONAL DISSOCIATED AND ORGANOTYPIC CNS CULTURES FROM CORTEX, STRIATUM AND CEREBELLUM AND P2 RECEPTORS CAN MEDIATE AND AGGRAVATE HYPOXIC SIGNALING IN MANY CNS NEURONS. CONVERSELY, SEVERAL P2 RECEPTOR ANTAGONISTS ABOLISH THE CELL DEATH FATE OF PRIMARY NEURONAL CULTURES EXPOSED TO EXCESSIVE GLUTAMATE, SERUM/POTASSIUM DEPRIVATION, HYPOGLYCEMIA AND CHEMICAL HYPOXIA. IN PARALLEL WITH THESE DETRIMENTAL EFFECTS, ALSO TROPHIC FUNCTIONS HAVE BEEN EXTENSIVELY DESCRIBED FOR EXTRACELLULAR PURINES (BOTH FOR NEURONAL AND NON-NEURONAL CELLS), BUT THESE MIGHT EITHER AGGRAVATE OR AMELIORATE THE NORMAL CELLULAR CONDITIONS. IN SUMMARY, EXTRACELLULAR ATP PLAYS A VERY COMPLEX ROLE NOT ONLY IN THE REPAIR, REMODELING AND SURVIVAL OCCURRING IN THE NERVOUS SYSTEM, BUT EVEN IN CELL DEATH AND THIS CAN OCCUR EITHER AFTER NORMAL DEVELOPMENTAL CONDITIONS, AFTER INJURY, OR ACUTE AND CHRONIC DISEASES. 2003 6 2770 31 EXTENDING INJURY- AND DISEASE-RESISTANT CNS PHENOTYPES BY REPETITIVE EPIGENETIC CONDITIONING. SIGNIFICANT REDUCTIONS IN THE EXTENT OF ACUTE INJURY IN THE CNS CAN BE ACHIEVED BY EXPOSURE TO DIFFERENT PRECONDITIONING STIMULI, BUT THE DURATION OF THE INDUCED PROTECTIVE PHENOTYPE IS TYPICALLY SHORT-LASTING, AND THUS IS DEEMED AS LIMITING ITS CLINICAL APPLICABILITY. EXTENDING THE PERIOD OVER WHICH SUCH ADAPTIVE EPIGENETIC CHANGES PERSIST - IN EFFECT, EXPANDING CONDITIONING'S "THERAPEUTIC WINDOW" - WOULD SIGNIFICANTLY BROADEN THE POTENTIAL APPLICATIONS OF SUCH A TREATMENT APPROACH IN PATIENTS. THE FREQUENCY OF THE CONDITIONING STIMULUS MAY HOLD THE KEY. WHILE TRANSIENT (1-3 DAYS) PROTECTION AGAINST CNS ISCHEMIC INJURY IS WELL ESTABLISHED PRECLINICALLY FOLLOWING A SINGLE PRECONDITIONING STIMULUS, REPETITIVELY PRESENTING PRECONDITIONING STIMULI EXTENDS THE DURATION OF ISCHEMIC TOLERANCE BY MANY WEEKS. MOREOVER, REPETITIVE INTERMITTENT POSTCONDITIONING ENHANCES POST-ISCHEMIC RECOVERY METRICS AND IMPROVES LONG-TERM SURVIVAL. INTERMITTENT CONDITIONING IS ALSO EFFICACIOUS FOR PREVENTING OR DELAYING INJURY IN PRECLINICAL MODELS OF CHRONIC NEURODEGENERATIVE DISEASE, AND FOR PROMOTING LONG-LASTING FUNCTIONAL IMPROVEMENTS IN A NUMBER OF OTHER PATHOLOGIES AS WELL. ALTHOUGH THE DETAILED MECHANISMS UNDERLYING THESE PROTRACTED KINDS OF NEUROPLASTICITY REMAIN LARGELY UNSTUDIED, ACCUMULATING EMPIRICAL EVIDENCE SUPPORTS THE CONTENTION THAT ALL OF THESE ADAPTIVE PHENOTYPES ARE EPIGENETICALLY MEDIATED. GOING FORWARD, ADDITIONAL PRECLINICAL DEMONSTRATIONS OF THE ABILITY TO INDUCE SUSTAINED BENEFICIAL PHENOTYPES THAT REDUCE THE BURDEN OF ACUTE AND CHRONIC NEURODEGENERATION, AND EXPERIMENTAL INTERROGATIONS OF THE REGULATORY CONSTRUCTS RESPONSIBLE FOR THESE EPIGENETIC RESPONSES, WILL ACCELERATE THE IDENTIFICATION OF NOT ONLY EFFICACIOUS BUT ALSO PRACTICAL, ADAPTIVE EPIGENETICS-BASED TREATMENTS FOR INDIVIDUALS WITH NEUROLOGICAL DISEASE. 2015 7 1761 39 EARLY STRESS EVOKES AGE-DEPENDENT BIPHASIC CHANGES IN HIPPOCAMPAL NEUROGENESIS, BDNF EXPRESSION, AND COGNITION. BACKGROUND: ADULT-ONSET STRESSORS EXERT OPPOSING EFFECTS ON HIPPOCAMPAL NEUROGENESIS AND COGNITION, WITH ENHANCEMENT OBSERVED FOLLOWING MILD STRESS AND DYSFUNCTION FOLLOWING SEVERE CHRONIC STRESS. WHILE EARLY LIFE STRESS EVOKES PERSISTENT CHANGES IN ANXIETY, IT IS UNKNOWN WHETHER EARLY STRESS DIFFERENTIALLY REGULATES HIPPOCAMPAL NEUROGENESIS, TROPHIC FACTOR EXPRESSION, AND COGNITION ACROSS THE LIFE SPAN. METHODS: HIPPOCAMPAL-DEPENDENT COGNITIVE BEHAVIOR, NEUROGENESIS, AND EPIGENETIC REGULATION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) EXPRESSION WAS EXAMINED AT DISTINCT TIME POINTS ACROSS THE LIFE SPAN IN RATS SUBJECTED TO THE EARLY STRESS OF MATERNAL SEPARATION (ES) AND CONTROL GROUPS. WE ALSO EXAMINED THE INFLUENCE OF CHRONIC ANTIDEPRESSANT TREATMENT ON THE NEUROGENIC, NEUROTROPHIC, AND COGNITIVE CHANGES IN MIDDLE-AGED ES ANIMALS. RESULTS: ANIMALS SUBJECTED TO EARLY STRESS OF MATERNAL SEPARATION EXAMINED DURING POSTNATAL LIFE AND YOUNG ADULTHOOD EXHIBITED ENHANCED HIPPOCAMPAL NEUROGENESIS, DECREASED REPRESSIVE HISTONE METHYLATION AT THE BDNF IV PROMOTER ALONG WITH ENHANCED BDNF LEVELS, AND IMPROVED PERFORMANCE ON THE STRESS-ASSOCIATED MORRIS WATER MAZE. STRIKINGLY, OPPOSING CHANGES IN HIPPOCAMPAL NEUROGENESIS AND EPIGENETIC REGULATION OF BDNF IV EXPRESSION, CONCOMITANT WITH IMPAIRMENTS ON HIPPOCAMPAL-DEPENDENT COGNITIVE TASKS, WERE OBSERVED IN MIDDLE-AGED ES ANIMALS. CHRONIC ANTIDEPRESSANT TREATMENT WITH AMITRIPTYLINE ATTENUATED THE MALADAPTIVE NEUROGENIC, EPIGENETIC, TRANSCRIPTIONAL, AND COGNITIVE EFFECTS IN MIDDLE-AGED ES ANIMALS. CONCLUSIONS: OUR STUDY PROVIDES NOVEL INSIGHTS INTO THE SHORT- AND LONG-TERM CONSEQUENCES OF ES, DEMONSTRATING BOTH BIPHASIC AND UNIQUE, AGE-DEPENDENT CHANGES AT THE MOLECULAR, EPIGENETIC, NEUROGENIC, AND BEHAVIORAL LEVELS. THESE RESULTS INDICATE THAT EARLY STRESS MAY TRANSIENTLY ENDOW ANIMALS WITH A POTENTIAL ADAPTIVE ADVANTAGE IN STRESSFUL ENVIRONMENTS BUT ACROSS A LIFE SPAN IS ASSOCIATED WITH LONG-TERM DELETERIOUS EFFECTS. 2013 8 211 24 ACTIVITY-DEPENDENT A-TO-I RNA EDITING IN RAT CORTICAL NEURONS. CHANGES IN NEURAL ACTIVITY INFLUENCE SYNAPTIC PLASTICITY/SCALING, GENE EXPRESSION, AND EPIGENETIC MODIFICATIONS. WE PRESENT THE FIRST EVIDENCE THAT SHORT-TERM AND PERSISTENT CHANGES IN NEURAL ACTIVITY CAN ALTER ADENOSINE-TO-INOSINE (A-TO-I) RNA EDITING, A POST-TRANSCRIPTIONAL SITE-SPECIFIC MODIFICATION FOUND IN SEVERAL NEURON-SPECIFIC TRANSCRIPTS. IN RAT CORTICAL NEURON CULTURES, ACTIVITY-DEPENDENT CHANGES IN A-TO-I RNA EDITING IN CODING EXONS ARE PRESENT AFTER 6 HR OF HIGH POTASSIUM DEPOLARIZATION BUT NOT AFTER 1 HR AND REQUIRE CALCIUM ENTRY INTO NEURONS. WHEN TREATMENTS ARE EXTENDED FROM HOURS TO DAYS, WE OBSERVE A NEGATIVE FEEDBACK PHENOMENON: CHRONIC DEPOLARIZATION INCREASES EDITING AT MANY SITES AND CHRONIC SILENCING DECREASES EDITING. WE PRESENT SEVERAL DIFFERENT MODULATIONS OF NEURAL ACTIVITY THAT CHANGE THE EXPRESSION OF DIFFERENT MRNA ISOFORMS THROUGH EDITING. 2012 9 231 24 ADAPTIVE CARDIORESPIRATORY CHANGES TO CHRONIC CONTINUOUS AND INTERMITTENT HYPOXIA. THIS CHAPTER REVIEWS CARDIORESPIRATORY ADAPTATIONS TO CHRONIC HYPOXIA (CH) EXPERIENCED AT HIGH ALTITUDE AND CARDIORESPIRATORY PATHOLOGIES ELICITED BY CHRONIC INTERMITTENT HYPOXIA (CIH) OCCURRING WITH OBSTRUCTIVE SLEEP APNEA (OSA). SHORT-TERM CH INCREASES BREATHING (VENTILATORY ACCLIMATIZATION TO HYPOXIA) AND BLOOD PRESSURE (BP) THROUGH CAROTID BODY (CB) CHEMO REFLEX. HYPERPLASIA OF GLOMUS CELLS, ALTERATIONS IN ION CHANNELS, AND RECRUITMENT OF ADDITIONAL EXCITATORY MOLECULES ARE IMPLICATED IN THE HEIGHTENED CB CHEMO REFLEX BY CH. TRANSCRIPTIONAL ACTIVATION OF HYPOXIA-INDUCIBLE FACTORS (HIF-1 AND 2) IS A MAJOR MOLECULAR MECHANISM UNDERLYING RESPIRATORY ADAPTATIONS TO SHORT-TERM CH. HIGH-ALTITUDE NATIVES EXPERIENCING LONG-TERM CH EXHIBIT BLUNTED HYPOXIC VENTILATORY RESPONSE (HVR) AND REDUCED BP DUE TO DESENSITIZATION OF CB RESPONSE TO HYPOXIA AND IMPAIRED PROCESSING OF CB SENSORY INFORMATION AT THE CENTRAL NERVOUS SYSTEM. VENTILATORY CHANGES EVOKED BY LONG-TERM CH ARE NOT READILY REVERSED AFTER RETURN TO SEA LEVEL. OSA PATIENTS AND RODENTS SUBJECTED TO CIH EXHIBIT HEIGHTENED CB CHEMO REFLEX, INCREASED HYPOXIC VENTILATORY RESPONSE, AND HYPERTENSION. INCREASED GENERATION OF REACTIVE OXYGEN SPECIES (ROS) IS A MAJOR CELLULAR MECHANISM UNDERLYING CIH-INDUCED ENHANCED CB CHEMO REFLEX AND THE ENSUING CARDIORESPIRATORY PATHOLOGIES. ROS GENERATION BY CIH IS MEDIATED BY NONTRANSCRIPTIONAL, DISRUPTED HIF-1 AND HIF-2-DEPENDENT TRANSCRIPTIONS AS WELL AS EPIGENETIC MECHANISMS. 2022 10 3973 32 LONG-TERM BEHAVIORAL AND NEUROENDOCRINE ALTERATIONS FOLLOWING CHRONIC SOCIAL STRESS IN MICE: IMPLICATIONS FOR STRESS-RELATED DISORDERS. THE PERIOD OF ADOLESCENCE IS CHARACTERIZED BY A HIGH VULNERABILITY TO STRESS AND TRAUMA, WHICH MIGHT RESULT IN LONG-LASTING CONSEQUENCES AND AN INCREASED RISK TO DEVELOP PSYCHIATRIC DISORDERS. USING A RECENTLY DEVELOPED MOUSE MODEL FOR CHRONIC SOCIAL STRESS DURING ADOLESCENCE, WE STUDIED PERSISTENT NEUROENDOCRINE AND BEHAVIORAL EFFECTS OF CHRONIC SOCIAL STRESS OBTAINED 12 MONTHS AFTER CESSATION OF THE STRESSOR. AS A REFERENCE, WE INVESTIGATED IMMEDIATE EFFECTS OF CHRONIC STRESS EXPOSURE OBTAINED AT THE END OF THE CHRONIC STRESS PERIOD. IMMEDIATELY AFTER THE 7 WEEK CHRONIC STRESS PERIOD STRESSED ANIMALS SHOW SIGNIFICANTLY INCREASED ADRENAL WEIGHTS, DECREASED THYMUS WEIGHT, INCREASED BASAL CORTICOSTERONE SECRETION AND A FLATTENED CIRCADIAN RHYTHM. FURTHERMORE, STRESSED ANIMALS DISPLAY AN INCREASED ANXIETY-LIKE BEHAVIOR IN THE ELEVATED PLUS MAZE AND THE NOVELTY-INDUCED SUPPRESSION OF FEEDING TEST. HIPPOCAMPAL MINERALOCORTICOID RECEPTOR (MR) AND THE GLUCOCORTICOID RECEPTOR (GR) MRNA LEVELS WERE SIGNIFICANTLY DECREASED. TO INVESTIGATE PERSISTENT CONSEQUENCES OF THIS EARLY STRESSFUL EXPERIENCE, THE SAME PARAMETERS WERE ASSESSED IN AGED MICE 12 MONTHS AFTER THE CESSATION OF THE STRESSOR. INTERESTINGLY, WE STILL FOUND DIFFERENCES BETWEEN FORMERLY STRESSED AND CONTROL MICE IN IMPORTANT STRESS-RELATED PARAMETERS. MR EXPRESSION LEVELS WERE SIGNIFICANTLY LOWER IN STRESSED ANIMALS, SUGGESTING LASTING, POSSIBLY EPIGENETIC ALTERATIONS IN GENE EXPRESSION REGULATION. FURTHERMORE, WE OBSERVED LONG-TERM BEHAVIORAL ALTERATIONS IN ANIMALS STRESSED DURING ADOLESCENCE. THUS, WE COULD DEMONSTRATE THAT CHRONIC STRESS EXPOSURE DURING A CRUCIAL DEVELOPMENTAL TIME PERIOD RESULTS IN LONG-TERM, PERSISTENT EFFECTS ON PHYSIOLOGICAL AND BEHAVIORAL PARAMETERS THROUGHOUT LIFE, WHICH MAY CONTRIBUTE TO AN ENHANCED VULNERABILITY TO STRESS-INDUCED DISEASES. 2008 11 3587 35 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 12 3971 41 LONG-LASTING NEUROTOXIC EFFECTS OF EXPOSURE TO METHYLMERCURY DURING DEVELOPMENT. AMONGST ENVIRONMENTAL CHEMICAL CONTAMINANTS, METHYLMERCURY (MEHG) REMAINS A MAJOR CONCERN BECAUSE OF ITS DETRIMENTAL EFFECTS ON DEVELOPING ORGANISMS, WHICH APPEAR TO BE PARTICULARLY SUSCEPTIBLE TO ITS TOXICITY. HERE, WE INVESTIGATED THE EFFECTS OF LOW MEHG LEVELS ON THE DEVELOPMENT OF THE NERVOUS SYSTEM USING BOTH IN VITRO AND IN VIVO EXPERIMENTAL MODELS. IN NEURAL STEM CELLS (NSCS), MEHG DECREASED PROLIFERATION AND NEURONAL DIFFERENTIATION AND INDUCED CELLULAR SENESCENCE ASSOCIATED WITH IMPAIRMENT IN MITOCHONDRIAL FUNCTION AND A CONCOMITANT DECREASE IN GLOBAL DNA METHYLATION. INTERESTINGLY, THE EFFECTS WERE HERITABLE AND COULD BE OBSERVED IN DAUGHTER NSCS NEVER DIRECTLY EXPOSED TO MEHG. BY CHRONICALLY EXPOSING PREGNANT/LACTATING MICE TO MEHG, WE FOUND PERSISTENT BEHAVIOURAL CHANGES IN THE MALE OFFSPRING, WHICH EXHIBITED DEPRESSION-LIKE BEHAVIOUR THAT COULD BE REVERSED BY CHRONIC TREATMENT WITH THE ANTIDEPRESSANT FLUOXETINE. THE BEHAVIOURAL ALTERATIONS WERE ASSOCIATED WITH A DECREASED NUMBER OF PROLIFERATING CELLS AND LOWER EXPRESSION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) MRNA IN THE HIPPOCAMPAL DENTATE GYRUS. MEHG EXPOSURE ALSO INDUCED LONG-LASTING DNA HYPERMETHYLATION, INCREASED HISTONE H3-K27 TRI-METHYLATION AND DECREASED H3 ACETYLATION AT THE BDNF PROMOTER IV, INDICATING THAT EPIGENETIC MECHANISMS PLAY A CRITICAL ROLE IN MEDIATING THE LONG-LASTING EFFECTS OF PERINATAL EXPOSURE TO MEHG. FLUOXETINE TREATMENT RESTORED THE BDNF MRNA EXPRESSION LEVELS, AS WELL AS THE NUMBER OF PROLIFERATING CELLS IN THE GRANULE CELL LAYER OF THE DENTATE GYRUS, WHICH FURTHER SUPPORTS THE HYPOTHESIS THAT LINKS DEPRESSION TO IMPAIRED NEUROGENESIS. ALTOGETHER, OUR FINDINGS HAVE SHOWN THAT LOW CONCENTRATIONS OF MEHG INDUCE LONG-LASTING EFFECTS IN NSCS THAT CAN POTENTIALLY PREDISPOSE INDIVIDUALS TO DEPRESSION, WHICH WE HAVE REPORTED EARLIER TO OCCUR IN EXPERIMENTAL ANIMALS EXPOSED TO MEHG DURING PRENATAL AND EARLY POSTNATAL DEVELOPMENT. 2013 13 4938 23 PATERNAL NICOTINE ENHANCES FEAR MEMORY, REDUCES NICOTINE ADMINISTRATION, AND ALTERS HIPPOCAMPAL GENETIC AND NEURAL FUNCTION IN OFFSPRING. NICOTINE USE REMAINS HIGHLY PREVALENT WITH TOBACCO AND E-CIGARETTE PRODUCTS CONSUMED WORLDWIDE. HOWEVER, INCREASING EVIDENCE OF TRANSGENERATIONAL EPIGENETIC INHERITANCE SUGGESTS THAT NICOTINE USE MAY ALTER BEHAVIOR AND NEUROBIOLOGY IN SUBSEQUENT GENERATIONS. WE TESTED THE EFFECTS OF CHRONIC PATERNAL NICOTINE EXPOSURE IN C57BL6/J MICE ON FEAR CONDITIONING IN F1 AND F2 OFFSPRING, AS WELL AS CONDITIONED FEAR EXTINCTION AND SPONTANEOUS RECOVERY, NICOTINE SELF-ADMINISTRATION, HIPPOCAMPAL CHOLINERGIC FUNCTIONING, RNA EXPRESSION, AND DNA METHYLATION IN F1 OFFSPRING. PATERNAL NICOTINE EXPOSURE WAS ASSOCIATED WITH ENHANCED CONTEXTUAL AND CUED FEAR CONDITIONING AND SPONTANEOUS RECOVERY OF EXTINGUISHED FEAR MEMORIES. FURTHER, NICOTINE REINFORCEMENT WAS REDUCED IN NICOTINE-SIRED MICE, AS ASSESSED IN A SELF-ADMINISTRATION PARADIGM. THESE BEHAVIORAL PHENOTYPES WERE COUPLED WITH ALTERED RESPONSE TO NICOTINE, UPREGULATED HIPPOCAMPAL NICOTINIC ACETYLCHOLINE RECEPTOR BINDING, REDUCED EVOKED HIPPOCAMPAL CHOLINERGIC CURRENTS, AND ALTERED METHYLATION AND EXPRESSION OF HIPPOCAMPAL GENES RELATED TO NEURAL DEVELOPMENT AND PLASTICITY. GENE EXPRESSION ANALYSIS SUGGESTS MULTIGENERATIONAL EFFECTS ON BROADER GENE NETWORKS POTENTIALLY INVOLVED IN NEUROPLASTICITY AND MENTAL DISORDERS. THE CHANGES IN FEAR CONDITIONING SIMILARLY SUGGEST PHENOTYPES ANALOGOUS TO ANXIETY DISORDERS SIMILAR TO POST-TRAUMATIC STRESS. 2021 14 3715 44 INHERITED EFFECTS OF LOW-DOSE EXPOSURE TO METHYLMERCURY IN NEURAL STEM CELLS. METHYLMERCURY (MEHG) IS AN ENVIRONMENTAL CONTAMINANT WITH RECOGNIZED NEUROTOXIC EFFECTS, PARTICULARLY TO THE DEVELOPING NERVOUS SYSTEM. IN THE PRESENT STUDY, WE SHOW THAT NANOMOLAR CONCENTRATIONS OF MEHG CAN INDUCE LONG-LASTING EFFECTS IN NEURAL STEM CELLS (NSCS). WE INVESTIGATED SHORT-TERM DIRECT AND LONG-TERM INHERITED EFFECTS OF EXPOSURE TO MEHG (2.5 OR 5.0 NM) USING PRIMARY CULTURES OF RAT EMBRYONIC CORTICAL NSCS. WE FOUND THAT MEHG HAD NO ADVERSE EFFECT ON CELL VIABILITY BUT REDUCED NSC PROLIFERATION AND ALTERED THE EXPRESSION OF CELL CYCLE REGULATORS (P16 AND P21) AND SENESCENCE-ASSOCIATED MARKERS. IN ADDITION, WE DEMONSTRATED A DECREASE IN GLOBAL DNA METHYLATION IN THE EXPOSED CELLS, INDICATING THAT EPIGENETIC CHANGES MAY BE INVOLVED IN THE MECHANISMS UNDERLYING THE MEHG-INDUCED EFFECTS. THESE CHANGES WERE OBSERVED IN CELLS DIRECTLY EXPOSED TO MEHG (PARENT CELLS) AND IN THEIR DAUGHTER CELLS CULTURED UNDER MEHG-FREE CONDITIONS. IN AGREEMENT WITH OUR IN VITRO DATA, A TREND WAS FOUND FOR DECREASED CELL PROLIFERATION IN THE SUBGRANULAR ZONE IN THE HIPPOCAMPI OF ADULT MICE EXPOSED TO LOW DOSES OF MEHG DURING THE PERINATAL PERIOD. INTERESTINGLY, THIS IMPAIRED PROLIFERATION HAD A MEASURABLE IMPACT ON THE TOTAL NUMBER OF NEURONS IN THE HIPPOCAMPAL DENTATE GYRUS. IMPORTANTLY, THIS EFFECT COULD BE REVERSED BY CHRONIC ANTIDEPRESSANT TREATMENT. OUR STUDY PROVIDES NOVEL EVIDENCE FOR PROGRAMMING EFFECTS INDUCED BY MEHG IN NSCS AND SUPPORTS THE IDEA THAT DEVELOPMENTAL EXPOSURE TO LOW LEVELS OF MEHG MAY RESULT IN LONG-TERM CONSEQUENCES PREDISPOSING TO NEURODEVELOPMENTAL DISORDERS AND/OR NEURODEGENERATION. 2012 15 243 36 ADOLESCENT CHRONIC INTERMITTENT TOLUENE INHALATION DYNAMICALLY REGULATES THE TRANSCRIPTOME AND NEURONAL METHYLOME WITHIN THE RAT MEDIAL PREFRONTAL CORTEX. INHALANTS CONTAINING THE VOLATILE SOLVENT TOLUENE ARE MISUSED TO INDUCE EUPHORIA OR INTOXICATION. INHALANT ABUSE IS MOST COMMON DURING ADOLESCENCE AND CAN RESULT IN COGNITIVE IMPAIRMENTS DURING AN IMPORTANT MATURATIONAL PERIOD. DESPITE EVIDENCE SUGGESTING THAT EPIGENETIC MODIFICATIONS MAY UNDERPIN THE COGNITIVE EFFECTS OF INHALANTS, NO STUDIES TO DATE HAVE THOROUGHLY INVESTIGATED TOLUENE-INDUCED REGULATION OF THE TRANSCRIPTOME OR DISCRETE EPIGENETIC MODIFICATIONS WITHIN THE BRAIN. TO ADDRESS THIS, WE INVESTIGATED EFFECTS OF ADOLESCENT CHRONIC INTERMITTENT TOLUENE (CIT) INHALATION ON GENE EXPRESSION AND DNA METHYLATION PROFILES WITHIN THE RAT MEDIAL PREFRONTAL CORTEX (MPFC), WHICH UNDERGOES MATURATION THROUGHOUT ADOLESCENCE AND HAS BEEN IMPLICATED IN TOLUENE-INDUCED COGNITIVE DEFICITS. EMPLOYING BOTH RNA-SEQ AND GENOME-WIDE METHYL CPG BINDING DOMAIN (MBD) ULTRA-SEQ ANALYSIS, WE DEMONSTRATE THAT ADOLESCENT CIT INHALATION (10 000 PPM FOR 1 H/DAY, 3 DAYS/WEEK FOR 4 WEEKS) INDUCES BOTH TRANSIENT AND PERSISTENT CHANGES TO THE TRANSCRIPTOME AND DNA METHYLOME WITHIN THE RAT MPFC FOR AT LEAST 2 WEEKS FOLLOWING TOLUENE EXPOSURE. WE DEMONSTRATE FOR THE FIRST TIME THAT ADOLESCENT CIT EXPOSURE RESULTS IN DYNAMIC REGULATION OF THE MPFC TRANSCRIPTOME LIKELY RELATING TO ACUTE INFLAMMATORY RESPONSES AND PERSISTENT DEFICITS IN SYNAPTIC PLASTICITY. THESE ADAPTATIONS MAY CONTRIBUTE TO THE COGNITIVE DEFICITS ASSOCIATED WITH CHRONIC TOLUENE EXPOSURE AND PROVIDE NOVEL MOLECULAR TARGETS FOR PREVENTING LONG-TERM NEUROPHYSIOLOGICAL ABNORMALITIES FOLLOWING CHRONIC TOLUENE INHALATION. 2021 16 2473 33 EPIGENETIC TREATMENTS OF ADULT RATS PROMOTE RECOVERY FROM VISUAL ACUITY DEFICITS INDUCED BY LONG-TERM MONOCULAR DEPRIVATION. IN MAMMALS THE DEVELOPMENT OF THE VISUAL SYSTEM MAY BE ALTERED DURING A SENSITIVE PERIOD BY MODIFYING THE VISUAL INPUT TO ONE OR BOTH EYES. THESE PLASTIC PROCESSES ARE REDUCED AFTER THE END OF THE SENSITIVE PERIOD. IT HAS BEEN PROPOSED THAT REDUCED LEVELS OF PLASTICITY ARE AT THE BASIS OF THE LACK OF RECOVERY FROM EARLY VISUAL DEPRIVATION OBSERVED IN ADULT ANIMALS. A DEVELOPMENTAL DOWNREGULATION OF EXPERIENCE-DEPENDENT REGULATION OF HISTONE ACETYLATION HAS RECENTLY BEEN FOUND TO BE INVOLVED IN CLOSING THE SENSITIVE PERIOD. THEREFORE, WE TESTED WHETHER PHARMACOLOGICAL EPIGENETIC TREATMENTS INCREASING HISTONE ACETYLATION COULD BE USED TO REVERSE VISUAL ACUITY DEFICITS INDUCED BY LONG-TERM MONOCULAR DEPRIVATION INITIATED DURING THE SENSITIVE PERIOD. WE FOUND THAT CHRONIC INTRAPERITONEAL ADMINISTRATION OF VALPROIC ACID OR SODIUM BUTYRATE (TWO DIFFERENT HISTONE DEACETYLASES INHIBITORS) TO LONG-TERM MONOCULARLY DEPRIVED ADULT RATS COUPLED WITH REVERSE LID-SUTURING CAUSED A COMPLETE RECOVERY OF VISUAL ACUITY, TESTED ELECTROPHYSIOLOGICALLY AND BEHAVIORALLY. THUS, MANIPULATIONS OF THE EPIGENETIC MACHINERY CAN BE USED TO PROMOTE FUNCTIONAL RECOVERY FROM EARLY ALTERATIONS OF SENSORY INPUT IN THE ADULT CORTEX. 2010 17 2827 33 FLUOXETINE INCREASES HIPPOCAMPAL NEUROGENESIS AND INDUCES EPIGENETIC FACTORS BUT DOES NOT IMPROVE FUNCTIONAL RECOVERY AFTER TRAUMATIC BRAIN INJURY. THE SELECTIVE SEROTONIN REUPTAKE INHIBITOR FLUOXETINE INDUCES HIPPOCAMPAL NEUROGENESIS, STIMULATES MATURATION AND SYNAPTIC PLASTICITY OF ADULT HIPPOCAMPAL NEURONS, AND REDUCES MOTOR/SENSORY AND MEMORY IMPAIRMENTS IN SEVERAL CNS DISORDERS. IN THE SETTING OF TRAUMATIC BRAIN INJURY (TBI), ITS EFFECTS ON NEUROPLASTICITY AND FUNCTION HAVE YET TO BE THOROUGHLY INVESTIGATED. HERE WE EXAMINED THE EFFICACY OF FLUOXETINE AFTER A MODERATE TO SEVERE TBI, PRODUCED BY A CONTROLLED CORTICAL IMPACT. THREE DAYS AFTER TBI OR SHAM SURGERY, MICE WERE TREATED WITH FLUOXETINE (10 MG/KG/D) OR VEHICLE FOR 4 WEEKS. TO EVALUATE THE EFFECTS OF FLUOXETINE ON NEUROPLASTICITY, HIPPOCAMPAL NEUROGENESIS AND EPIGENETIC MODIFICATION WERE STUDIED. STEREOLOGIC ANALYSIS OF THE DENTATE GYRUS REVEALED A SIGNIFICANT INCREASE IN DOUBLECORTIN-POSITIVE CELLS IN BRAIN-INJURED ANIMALS TREATED WITH FLUOXETINE RELATIVE TO CONTROLS, A FINDING CONSISTENT WITH ENHANCED HIPPOCAMPAL NEUROGENESIS. EPIGENETIC MODIFICATIONS, INCLUDING AN INCREASE IN HISTONE 3 ACETYLATION AND INDUCTION OF METHYL-CPG-BINDING PROTEIN, A TRANSCRIPTION FACTOR INVOLVED IN DNA METHYLATION, WERE LIKEWISE SEEN BY IMMUNOHISTOCHEMISTRY AND QUANTITATIVE WESTERN IMMUNOBLOTS, RESPECTIVELY, IN BRAIN-INJURED ANIMALS TREATED WITH FLUOXETINE. TO DETERMINE IF FLUOXETINE IMPROVES NEUROLOGICAL OUTCOMES AFTER TBI, GAIT FUNCTION AND SPATIAL LEARNING AND MEMORY WERE ASSESSED BY THE CATWALK-ASSISTED GAIT TEST AND BARNES MAZE TEST, RESPECTIVELY. NO DIFFERENCES IN THESE PARAMETERS WERE SEEN BETWEEN FLUOXETINE- AND VEHICLE-TREATED ANIMALS. THUS WHILE FLUOXETINE ENHANCED NEUROPLASTICITY IN THE HIPPOCAMPUS AFTER TBI, ITS CHRONIC ADMINISTRATION DID NOT RESTORE LOCOMOTOR FUNCTION OR AMELIORATE MEMORY DEFICITS. 2011 18 892 32 CHRONIC ETHANOL EXPOSURE ALTERS DNA METHYLATION IN NEURAL STEM CELLS: ROLE OF MOUSE STRAIN AND SEX. PRENATAL ALCOHOL EXPOSURE (PAE) IS CONSIDERED AS A RISK FACTOR FOR THE DEVELOPMENT OF FETAL ALCOHOL SPECTRUM DISORDERS (FASD). EVIDENCE INDICATES THAT PAE AFFECTS EPIGENETIC MECHANISMS (SUCH AS DNA METHYLATION) AND ALTERS THE NORMAL DIFFERENTIATION AND DEVELOPMENT OF NEURAL STEM CELLS (NSC) IN THE FETAL BRAIN. HOWEVER, PAE EFFECTS DEPEND ON SEVERAL FACTORS SUCH AS SEX AND STRAIN OF THE STUDIED SUBJECTS. HERE, WE INVESTIGATED WHETHER MURINE SEX AND STRAIN CONTRIBUTE TO THE EFFECTS OF CHRONIC ETHANOL EXPOSURE ON DNA METHYLATION MACHINERY OF DIFFERENTIATING NSC. FURTHER, THE EFFECTS OF PAE ON GLIAL LINEAGE (INCLUDING BOTH ASTROCYTES AND OLIGODENDROCYTES) IN A SEX- AND STRAIN-DEPENDENT MANNER HAVE NOT BEEN STUDIED YET. TO EXAMINE THE EFFECTS OF CHRONIC ETHANOL EXPOSURE ON GLIOGENESIS, WE EXPOSED DIFFERENTIATING NSC TO GLIO-INDUCTIVE CULTURE CONDITIONS. APPLYING A STANDARD IN VITRO MODEL SYSTEM, WE TREATED MALE AND FEMALE DIFFERENTIATING NSC (OBTAINED FROM THE FOREBRAIN OF CD1 AND C57BL/6 EMBRYOS AT EMBRYONIC DAY 14.5) WITH CHRONIC ETHANOL EXPOSURE (70 MM) FOR 8 DAYS. WE SHOW THAT ETHANOL INDUCES GLOBAL DNA HYPOMETHYLATION, WHILE ALTERING THE EXPRESSION OF DNA METHYLATION-RELATED GENES IN A SEX- AND STRAIN-SPECIFIC MANNER. THE OBSERVED CHANGE IN CELLULAR DNA METHYLATION LEVELS WAS ASSOCIATED WITH ALTERED EXPRESSION OF GLIAL MARKERS CNPASE, GFAP, AND OLIG2 IN CD1 (BUT NOT C57BL/6) CELLS. WE CONCLUDE THAT THE IMPACT OF ETHANOL EFFECT ON DNA METHYLATION IS DEPENDENT ON CELLULAR SEX AND STRAIN. ALSO, ETHANOL IMPACT ON NEURAL STEM CELL FATE COMMITMENT WAS ONLY DETECTED IN CELLS ISOLATED FROM CD1 MOUSE STRAIN, BUT NOT IN C57BL/6 CELLS. THE RESULTS OF THE CURRENT STUDY PROVIDE EVIDENCE THAT SEX AND STRAIN OF RODENTS (C57BL/6 AND CD1) DURING GESTATION ARE IMPORTANT FACTORS, WHICH AFFECT ALCOHOL EFFECTS ON NSC DIFFERENTIATION AND DNA METHYLATION. RESULTS OF THIS STUDY MAY ALSO HELP IN INTERPRETING DATA ON THE DEVELOPMENTAL TOXICITY OF MANY COMPOUNDS DURING THE GESTATIONAL PERIOD. 2020 19 5313 29 PSYCHOLOGICAL STRESS AS A MODULATOR OF FUNCTIONAL RECOVERY FOLLOWING SPINAL CORD INJURY. THERE IS STRONG EVIDENCE INDICATING THAT THE SOCIAL ENVIRONMENT TRIGGERS CHANGES TO THE PSYCHOLOGICAL STRESS RESPONSE AND GLUCOCORTICOID RECEPTOR FUNCTION. CONSIDERABLE LITERATURE LINKS THE SUBSEQUENT CHANGES IN STRESS RESILIENCY TO PHYSICAL HEALTH. HERE, CONVERGING EVIDENCE FOR THE MODULATORY ROLE OF CHRONIC PSYCHOLOGICAL STRESS IN THE RECOVERY PROCESS FOLLOWING SPINAL CORD INJURY (SCI) IS PRESENTED. DESPITE THE CONSIDERABLE ADVANCES IN SCI RESEARCH, WE ARE STILL UNABLE TO IDENTIFY THE CAUSES OF VARIABILITY IN PATIENTS' RECOVERY FOLLOWING INJURY. WE PROPOSE THAT INDIVIDUALS' PAST AND PRESENT LIFE EXPERIENCES (IN THE FORM OF STRESS EXPOSURE) MAY SIGNIFICANTLY MODULATE PATIENTS' OUTCOME POST-SCI. WE PROPOSE A THEORETICAL MODEL TO EXPLAIN THE NEGATIVE IMPACT OF CHRONIC PSYCHOLOGICAL STRESS ON PHYSICAL AND PSYCHOLOGICAL RECOVERY. THE STRESS EXPERIENCED IN LIFE PRIOR TO SCI AND ALSO AS A RESULT OF THE TRAUMATIC INJURY, COULD COMPROMISE GLUCOCORTICOID RECEPTOR SENSITIVITY AND FUNCTION, AND CONTRIBUTE TO HIGH LEVELS OF INFLAMMATION AND APOPTOSIS POST-SCI, DECREASING THE TISSUE REMAINING AT THE INJURY SITE AND UNDERMINING RECOVERY OF FUNCTION. BOTH STRESS-INDUCED GLUCOCORTICOID RESISTANCE AND STRESS-INDUCED EPIGENETIC CHANGES TO THE GLUCOCORTICOID RECEPTOR CAN MODULATE THE NUCLEAR FACTOR-KAPPA B REGULATED INFLAMMATORY PATHWAYS AND THE BCL-2 REGULATED APOPTOSIS PATHWAYS. THIS MODEL NOT ONLY CONTRIBUTES TO THE THEORETICAL UNDERSTANDING OF THE RECOVERY PROCESS FOLLOWING INJURY, BUT ALSO PROVIDES CONCRETE TESTABLE HYPOTHESES FOR FUTURE STUDIES. 2014 20 6528 32 TRANSCRIPTIONAL CORRELATES OF CHRONIC ALCOHOL NEUROADAPTATION IN DROSOPHILA LARVAE. WHEN PRESENTED WITH THE CHOICE, DROSOPHILA MELANOGASTER FEMALES WILL OFTEN PREFER TO LAY EGGS ON FOOD CONTAINING A SIGNIFICANT AMOUNT OF ALCOHOL. WHILE, IN SOME CASES, THIS BEHAVIORAL DECISION CAN PROVIDE A SURVIVAL ADVANTAGE TO THE DEVELOPING LARVAE, IT CAN ALSO LEAD TO DEVELOPMENTAL AND COGNITIVE PROBLEMS. ALCOHOL CONSUMPTION CAN AFFECT EXECUTIVE FUNCTIONS, EPISODIC MEMORY, AND OTHER BRAIN FUNCTION CAPACITIES. HOWEVER, IN THE FRUIT FLY, THE INITIAL COGNITIVE EFFECTS OF ALCOHOL CONSUMPTION HAVE BEEN SHOWN TO REVERSE UPON PERSISTENT EXPOSURE TO ALCOHOL. USING AN OLFACTORY CONDITIONING ASSAY WHERE AN ODORANT IS IMPLEMENTED AS A CONDITIONED STIMULUS AND PAIRED WITH A HEAT SHOCK AS AN UNCONDITIONED STIMULUS, A PREVIOUS STUDY HAS SHOWN THAT WHEN EXPOSED TO A SHORT ACUTE DOSE OF ALCOHOL, DROSOPHILA LARVAE CAN NO LONGER LEARN THIS ASSOCIATION. INTERESTINGLY, UPON PROLONGED CHRONIC ALCOHOL EXPOSURE, LARVAE SEEM TO SUCCESSFULLY AVOID THE CONDITIONED STIMULUS JUST AS WELL AS CONTROL ALCOHOL-NAIVE LARVAE, SUGGESTIVE OF ALCOHOL-INDUCED NEUROADAPTATIONS. HOWEVER, THE MECHANISMS BY WHICH DROSOPHILA ADAPT TO THE PRESENCE OF ALCOHOL REMAINS UNKNOWN. IN THIS STUDY, WE EXPLORE THE TRANSCRIPTIONAL CORRELATES OF NEUROADAPTATION IN DROSOPHILA LARVAE EXPOSED TO CHRONIC ALCOHOL TO UNDERSTAND THE GENETIC AND CELLULAR COMPONENTS RESPONSIBLE FOR THIS ADAPTATION. FOR THIS, WE EMPLOYED RNA SEQUENCING TECHNOLOGY TO EVALUATE DIFFERENCES IN GENE EXPRESSION IN THE BRAIN OF LARVAE CHRONICALLY EXPOSED TO ALCOHOL. OUR RESULTS SUGGEST THAT ALCOHOL-INDUCED NEUROADAPTATIONS ARE MODULATED BY A DIVERSE ARRAY OF SYNAPTIC GENES WITHIN THE LARVAL BRAIN THROUGH A SERIES OF EPIGENETIC MODULATORS. 2021