1 1460 147 DISORDERS OF CONSCIOUSNESS AND PHARMACEUTICALS THAT ACT ON OXYGEN BASED AMINO ACID AND MONOAMINE NEUROTRANSMITTER PATHWAYS OF THE BRAIN. OXYGEN BASED NEUROTRANSMITTERS IN THE SYNAPSES OF THE BRAIN ARE PROPOSED TO PLAY AN IMPORTANT ROLE IN THE GENERATION OF CONSCIOUSNESS. THEY INCLUDE THE AMINO ACIDS GLUTAMATE AND GABA WHICH USE KREBS CYCLE PRECURSORS FOR THEIR SYNTHESIS, AND THE MONOAMINES DOPAMINE, NORADRENALIN, ADRENALIN AND SEROTONIN, WHICH ARE DERIVED FROM TYROSINE AND TRYPTOPHAN. DURING ISCHEMIA AFTER AN ACUTE BRAIN INJURY, A GABA SURGE OFTEN INITIATES BRAIN SUPPRESSION. IT HAS BEEN PROPOSED THAT WITH CHRONIC ISCHEMIA, A SECONDARY, POSSIBLY EPIGENETIC RESPONSE OCCURS WHEN NEUROTRANSMITTERS DEPLETE, A GLUCOSE AND OXYGEN SAVING MECHANISM TERMED NEURODORMANCY THAT MAY INVOKE ALTERNATIVE LONG TERM LOW ENERGY METABOLIC PATHWAYS IN THE BRAIN, ENCOUNTERED IN DISORDERS OF CONSCIOUSNESS. SOME MEDICATIONS CAN REVERSE DISORDERS OF CONSCIOUSNESS IN SOME PATIENTS. VIRTUALLY ALL OF THEM ACT ON NEUROTRANSMITTER SYSTEMS THAT USE OXYGEN AS A BUILDING BLOCK OR AS AN ENERGY SOURCE WITHIN THE BRAIN. PHARMACEUTICALS THAT ACT IN THE OXYGEN BASED AMINO ACID SYSTEMS OF THE BRAIN INCLUDE THE GABAERGIC MEDICATIONS ZOLPIDEM AND BACLOFEN, WHILE THOSE THAT ACT IN THE MONOAMINE AXES INCLUDE THE DOPAMINERGIC MEDICATIONS L DOPA, AMANTADINE, BROMOCRIPTINE, APOMORPHINE AND METHYLPHENIDATE, AND THE NORADRENERGIC AND SEROTONERGIC MEDICATIONS DESIPRAMINE, AMITRIPTYLINE, PROTRIPTYLINE AND FLUOXETINE. ANOTHER GROUP ARE THE CHOLINESTERASE INHIBITORS, RESPONSIBLE FOR INCREASING ACETYLCHOLINE, WHICH IS SYNTHESIZED FROM THE KREBS CYCLE INITIATOR, ACETYL COA. IT APPEARS THAT PHARMACEUTICALS THAT ARE ACTIVE IN THE OXYGEN BASED NEUROTRANSMITTER PATHWAYS OF THE BRAIN ARE SUCCESSFUL TO AROUSE TO CONSCIOUSNESS PATIENTS THAT SUFFER FROM ITS DISORDERS. RESEARCH NEEDS TO BE SUPPORTED AS FOUNDATION TO UNDERSTAND THE BIOCHEMICAL MECHANISMS THAT ARE INVOLVED IN CONSCIOUSNESS DISORDERS AND TO EXPLORE FURTHER THE PHARMACOLOGICAL TREATMENT POSSIBILITIES FOR THESE DEVASTATING NEUROLOGICAL CONDITIONS. 2014 2 533 33 ASTROCYTIC TRANSCRIPTION FACTOR REST UPREGULATES GLUTAMATE TRANSPORTER EAAT2, PROTECTING DOPAMINERGIC NEURONS FROM MANGANESE-INDUCED EXCITOTOXICITY. CHRONIC EXPOSURE TO HIGH LEVELS OF MANGANESE (MN) LEADS TO MANGANISM, A NEUROLOGICAL DISORDER WITH SIMILAR SYMPTOMS TO THOSE INHERENT TO PARKINSON'S DISEASE. HOWEVER, THE UNDERLYING MECHANISMS OF THIS PATHOLOGICAL CONDITION HAVE YET TO BE ESTABLISHED. SINCE THE HUMAN EXCITATORY AMINO ACID TRANSPORTER 2 (EAAT2) (GLUTAMATE TRANSPORTER 1 IN RODENTS) IS PREDOMINANTLY EXPRESSED IN ASTROCYTES AND ITS DYSREGULATION IS INVOLVED IN MN-INDUCED EXCITOTOXIC NEURONAL INJURY, CHARACTERIZATION OF THE MECHANISMS THAT MEDIATE THE MN-INDUCED IMPAIRMENT IN EAAT2 FUNCTION IS CRUCIAL FOR THE DEVELOPMENT OF NOVEL THERAPEUTICS AGAINST MN NEUROTOXICITY. REPRESSOR ELEMENT 1-SILENCING TRANSCRIPTION FACTOR (REST) EXERTS PROTECTIVE EFFECTS IN MANY NEURODEGENERATIVE DISEASES. BUT THE EFFECTS OF REST ON EAAT2 EXPRESSION AND ENSUING NEUROPROTECTION ARE UNKNOWN. GIVEN THAT THE EAAT2 PROMOTER CONTAINS REST BINDING SITES, THE PRESENT STUDY INVESTIGATED THE ROLE OF REST IN EAAT2 EXPRESSION AT THE TRANSCRIPTIONAL LEVEL IN ASTROCYTES AND MN-INDUCED NEUROTOXICITY IN AN ASTROCYTE-NEURON COCULTURE SYSTEM. THE RESULTS REVEAL THAT ASTROCYTIC REST POSITIVELY REGULATES EAAT2 EXPRESSION WITH THE RECRUITMENT OF AN EPIGENETIC MODIFIER, CAMP RESPONSE ELEMENT-BINDING PROTEIN-BINDING PROTEIN/P300, TO ITS CONSENSUS BINDING SITES IN THE EAAT2 PROMOTER. MOREOVER, ASTROCYTIC OVEREXPRESSION OF REST ATTENUATES MN-INDUCED REDUCTION IN EAAT2 EXPRESSION, LEADING TO ATTENUATION OF GLUTAMATE-INDUCED NEUROTOXICITY IN THE ASTROCYTE-NEURON COCULTURE SYSTEM. OUR FINDINGS DEMONSTRATE THAT ASTROCYTIC REST PLAYS A CRITICAL ROLE IN PROTECTION AGAINST MN-INDUCED NEUROTOXICITY BY ATTENUATING MN-INDUCED EAAT2 REPRESSION AND THE ENSUING EXCITOTOXIC DOPAMINERGIC NEURONAL INJURY. THIS INDICATES THAT ASTROCYTIC REST COULD BE A POTENTIAL MOLECULAR TARGET FOR THE TREATMENT OF MN TOXICITY AND OTHER NEUROLOGICAL DISORDERS ASSOCIATED WITH EAAT2 DYSREGULATION. 2021 3 3130 35 GLAST BUT NOT LEAST--DISTRIBUTION, FUNCTION, GENETICS AND EPIGENETICS OF L-GLUTAMATE TRANSPORT IN BRAIN--FOCUS ON GLAST/EAAT1. SYNAPTICALLY RELEASED L-GLUTAMATE, THE MOST IMPORTANT EXCITATORY NEUROTRANSMITTER IN THE CNS, IS REMOVED FROM EXTRACELLULAR SPACE BY FAST AND EFFICIENT TRANSPORT MEDIATED BY SEVERAL TRANSPORTERS; THE MOST ABUNDANT ONES ARE EAAT1/GLAST AND EAAT2/GLT1. THE REVIEW FIRST SUMMARIZES THEIR LOCATION, FUNCTIONS AND BASIC CHARACTERISTICS. WE THEN LOOK AT GENETICS AND EPIGENETICS OF EAAT1/GLAST AND EAAT2/GLT1 AND PERFORM IN SILICO ANALYSES OF THEIR PROMOTER REGIONS. THERE IS ONE CPG ISLAND IN SLC1A2 (EAAT2/GLT1) GENE AND NONE IN SLC1A3 (EAAT1/GLAST) SUGGESTING THAT DNA METHYLATION IS NOT THE MOST IMPORTANT EPIGENETIC MECHANISM REGULATING EAAT1/GLAST LEVELS IN BRAIN. THERE ARE TARGETS FOR SPECIFIC MIRNA IN SLC1A2 (EAAT2/GLT1) GENE. WE ALSO NOTE THAT WHILE DEFECTS IN EAAT2/GLT1 HAVE BEEN ASSOCIATED WITH VARIOUS PATHOLOGICAL STATES INCLUDING CHRONIC NEURODEGENERATIVE DISEASES, VERY LITTLE IS KNOWN ON POSSIBLE CONTRIBUTIONS OF DEFECTIVE OR DYSFUNCTIONAL EAAT1/GLAST TO ANY SPECIFIC BRAIN DISEASE. FINALLY, WE REVIEW EVIDENCE OF EAAT1/GLAST INVOLVEMENT IN MECHANISMS OF BRAIN RESPONSE TO ALCOHOLISM AND PRESENT SOME PRELIMINARY DATA SHOWING THAT ETHANOL, AT CONCENTRATIONS WHICH MAY BE REACHED FOLLOWING HEAVY DRINKING, CAN HAVE AN EFFECT ON THE DISTRIBUTION OF EAAT1/GLAST IN CULTURED ASTROCYTES; THE EFFECT IS BLOCKED BY BACLOFEN, A GABA-B RECEPTOR AGONIST AND A DRUG POTENTIALLY USEFUL IN THE TREATMENT OF ALCOHOLISM. WE ARGUE THAT MORE RESEARCH EFFORT SHOULD BE FOCUSED ON EAAT1/GLAST, PARTICULARLY IN RELATION TO ALCOHOLISM AND DRUG ADDICTION. 2015 4 2772 41 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 5 1734 36 EAAT2 AS A RESEARCH TARGET IN BIPOLAR DISORDER AND UNIPOLAR DEPRESSION: A SYSTEMATIC REVIEW. GLUTAMATE IS IMPLICATED IN THE NEUROPATHOLOGY OF BOTH MAJOR DEPRESSIVE DISORDER AND BIPOLAR DISORDER. EXCITATORY AMINO ACID TRANSPORTER 2 (EAAT2) IS THE MAJOR GLUTAMATE TRANSPORTER IN THE MAMMALIAN BRAIN, REMOVING GLUTAMATE FROM THE SYNAPTIC CLEFT AND TRANSPORTING IT INTO GLIA FOR RECYCLING. IT IS THEREBY THE PRINCIPAL REGULATOR OF EXTRACELLULAR GLUTAMATE LEVELS AND PREVENTS NEURONAL EXCITOTOXICITY. EAAT2 IS A PROMISING TARGET FOR ELUCIDATING THE MECHANISMS BY WHICH THE GLUTAMATE-GLUTAMINE CYCLE INTERACTS WITH NEURONAL SYSTEMS IN MOOD DISORDERS. FORTY EAAT2 STUDIES (PUBLISHED JANUARY 1992-JANUARY 2018) WERE IDENTIFIED VIA A SYSTEMATIC LITERATURE SEARCH. THE STUDIES DEMONSTRATED THAT CHRONIC STRESS/STEROIDS WERE MOST COMMONLY ASSOCIATED WITH DECREASED EAAT2. IN RODENTS, EAAT2 INHIBITION WORSENED DEPRESSIVE BEHAVIORS. HUMAN EAAT2 EXPRESSION USUALLY DECREASED IN DEPRESSION, WITH SOME REGIONAL BRAIN DIFFERENCES. FEWER DATA HAVE BEEN COLLECTED REGARDING THE ROLES AND REGULATION OF EAAT2 IN BIPOLAR DISORDER. FUTURE DIRECTIONS FOR RESEARCH INCLUDE CORRELATING EAAT2 AND GLUTAMATE LEVELS IN VIVO, ELUCIDATING GENETIC VARIABILITY AND EPIGENETIC REGULATION, CLARIFYING INTRACELLULAR PROTEIN AND PHARMACOLOGIC INTERACTIONS, AND EXAMINING EAAT2 IN DIFFERENT BIPOLAR MOOD STATES. AS PART OF A MACROMOLECULAR COMPLEX WITHIN GLIA, EAAT2 MAY CONTRIBUTE SIGNIFICANTLY TO INTRACELLULAR SIGNALING, ENERGY REGULATION, AND CELLULAR HOMEOSTASIS. AN ENHANCED UNDERSTANDING OF THIS SYSTEM IS NEEDED. 2020 6 6352 31 THE ROLE OF GABA(A) RECEPTORS IN THE DEVELOPMENT OF ALCOHOLISM. ALCOHOLISM IS A COMMON, HERITABLE, CHRONIC RELAPSING DISORDER. GABA(A) RECEPTORS UNDERGO ALLOSTERIC MODULATION BY ETHANOL, ANESTHETICS, BENZODIAZEPINES AND NEUROSTEROIDS AND HAVE BEEN IMPLICATED IN THE ACUTE AS WELL AS THE CHRONIC EFFECTS OF ETHANOL INCLUDING TOLERANCE, DEPENDENCE AND WITHDRAWAL. MEDICATIONS TARGETING GABA(A) RECEPTORS AMELIORATE THE SYMPTOMS OF ACUTE WITHDRAWAL. ETHANOL INDUCES PLASTICITY IN GABA(A) RECEPTORS: TOLERANCE IS ASSOCIATED WITH GENERALLY DECREASED GABA(A) RECEPTOR ACTIVATION AND DIFFERENTIALLY ALTERED SUBUNIT EXPRESSION. THE DOPAMINE (DA) MESOLIMBIC REWARD PATHWAY ORIGINATING IN THE VENTRAL TEGMENTAL AREA (VTA), AND INTERACTING STRESS CIRCUITRY PLAY AN IMPORTANT ROLE IN THE DEVELOPMENT OF ADDICTION. VTA GABAERGIC INTERNEURONS ARE THE PRIMARY INHIBITORY REGULATORS OF DA NEURONS AND A SUBSET OF VTA GABA(A) RECEPTORS MAY BE IMPLICATED IN THE SWITCH FROM HEAVY DRINKING TO DEPENDENCE. GABA(A) RECEPTORS MODULATE ANXIETY AND RESPONSE TO STRESS; IMPORTANT ELEMENTS OF SUSTAINED DRINKING AND RELAPSE. THE GABA(A) RECEPTOR SUBUNIT GENES CLUSTERED ON CHROMOSOME 4 ARE HIGHLY EXPRESSED IN THE REWARD PATHWAY. SEVERAL RECENT STUDIES HAVE PROVIDED STRONG EVIDENCE THAT ONE OF THESE GENES, GABRA2, IS IMPLICATED IN ALCOHOLISM IN HUMANS. THE INFLUENCE OF THE INTERACTION BETWEEN ETHANOL AND GABA(A) RECEPTORS IN THE REWARD PATHWAY ON THE DEVELOPMENT OF ALCOHOLISM TOGETHER WITH GENETIC AND EPIGENETIC VULNERABILITIES WILL BE EXPLORED IN THIS REVIEW. 2008 7 6139 35 THE ETIOLOGICAL CONTRIBUTION OF GABAERGIC PLASTICITY TO THE PATHOGENESIS OF NEUROPATHIC PAIN. NEUROPATHIC PAIN DEVELOPING AFTER PERIPHERAL OR CENTRAL NERVE INJURY IS THE RESULT OF PATHOLOGICAL CHANGES GENERATED THROUGH COMPLEX MECHANISMS. DISRUPTION IN THE HOMEOSTASIS OF EXCITATORY AND INHIBITORY NEURONS WITHIN THE CENTRAL NERVOUS SYSTEM IS A CRUCIAL FACTOR IN THE FORMATION OF HYPERALGESIA OR ALLODYNIA OCCURRING WITH NEUROPATHIC PAIN. THE CENTRAL GABAERGIC PATHWAY HAS RECEIVED ATTENTION FOR ITS EXTENSIVE DISTRIBUTION AND FUNCTION IN NEURAL CIRCUITS, INCLUDING THE GENERATION AND DEVELOPMENT OF NEUROPATHIC PAIN. GABAERGIC INHIBITORY CHANGES THAT OCCUR IN THE INTERNEURONS ALONG DESCENDING MODULATORY AND NOCICEPTIVE PATHWAYS IN THE CENTRAL NERVOUS SYSTEM ARE BELIEVED TO GENERATE NEURONAL PLASTICITY, SUCH AS SYNAPTIC PLASTICITY OR FUNCTIONAL PLASTICITY OF THE RELATED GENES OR PROTEINS, THAT IS THE FOUNDATION OF PERSISTENT NEUROPATHIC PAIN. THE PRIMARY GABAERGIC PLASTICITY OBSERVED IN NEUROPATHIC PAIN INCLUDES GABAERGIC SYNAPSE HOMO- AND HETEROSYNAPTIC PLASTICITY, DECREASED SYNTHESIS OF GABA, DOWN-EXPRESSION OF GLUTAMIC ACID DECARBOXYLASE AND GABA TRANSPORTER, ABNORMAL EXPRESSION OF NKCC1 OR KCC2, AND DISTURBED FUNCTION OF GABA RECEPTORS. IN THIS REVIEW, WE DESCRIBE POSSIBLE MECHANISMS ASSOCIATED WITH GABAERGIC PLASTICITY, SUCH AS CENTRAL SENSITIZATION AND GABAERGIC INTERNEURON APOPTOSIS, AND THE EPIGENETIC ETIOLOGIES OF GABAERGIC PLASTICITY IN NEUROPATHIC PAIN. MOREOVER, WE SUMMARIZE POTENTIAL THERAPEUTIC TARGETS OF GABAERGIC PLASTICITY THAT MAY ALLOW FOR SUCCESSFUL RELIEF OF HYPERALGESIA FROM NERVE INJURY. FINALLY, WE COMPARE THE EFFECTS OF THE GABAERGIC SYSTEM IN NEUROPATHIC PAIN TO OTHER TYPES OF CHRONIC PAIN TO UNDERSTAND THE CONTRIBUTION OF GABAERGIC PLASTICITY TO NEUROPATHIC PAIN. 2019 8 2934 30 GENETIC ADDICTION RISK SCORE (GARS) , A PREDICTOR OF VULNERABILITY TO OPIOID DEPENDENCE. THE INTERACTION OF NEUROTRANSMITTERS AND GENES THAT CONTROL THE RELEASE OF DOPAMINE IS THE BRAIN REWARD CASCADE (BRC). VARIATIONS WITHIN THE BRC, WHETHER GENETIC OR EPIGENETIC, MAY PREDISPOSE INDIVIDUALS TO ADDICTIVE BEHAVIORS AND ALTERED PAIN TOLERANCE. THIS DISCUSSION AUTHORED BY A GROUP OF CONCERNED SCIENTISTS AND CLINICIANS EXAMINES THE GENETIC ADDICTION RISK SCORE (GARS), THE FIRST TEST TO ACCURATELY PREDICT VULNERABILITY TO PAIN, ADDICTION, AND OTHER COMPULSIVE BEHAVIORS, DEFINED AS REWARD DEFICIENCY SYNDROME (RDS). INNOVATIVE STRATEGIES TO COMBAT EPIDEMIC OPIOID, IATROGENIC PRESCRIPTION DRUG ABUSE AND DEATH, BASED ON THE ROLE OF DOPAMINERGIC TONE IN PAIN PATHWAYS, ARE PROPOSED. SENSITIVITY TO PAIN MAY RESIDE IN THE MESOLIMBIC PROJECTION SYSTEM, WHERE GENETIC POLYMORPHISMS ASSOCIATE WITH A PREDISPOSITION TO PAIN VULNERABILITY OR TOLERANCE. THEY PROVIDE UNIQUE THERAPEUTIC TARGETS THAT COULD ASSIST IN THE TREATMENT OF PAIN, AND IDENTIFY RISK FOR SUBSEQUENT ADDICTION. PHARMACOGENOMIC TESTING OF CANDIDATE GENES LIKE CB1, MU RECEPTORS, AND PENK MIGHT RESULT IN PHARMACOGENOMIC, PERSONALIZED SOLUTIONS, AND IMPROVED CLINICAL OUTCOMES. GENETICALLY IDENTIFYING RISK FOR ALL RDS BEHAVIORS, ESPECIALLY IN COMPROMISED POPULATIONS, MAY BE A FRONTLINE TOOL TO ASSIST MUNICIPALITIES TO PROVIDE BETTER RESOURCE ALLOCATION. 2018 9 4848 28 OPIOID-INDUCED STRUCTURAL AND FUNCTIONAL PLASTICITY OF MEDIUM-SPINY NEURONS IN THE NUCLEUS ACCUMBENS. OPIOID USE DISORDER (OUD) IS A CHRONIC RELAPSING CLINICAL CONDITION WITH TREMENDOUS MORBIDITY AND MORTALITY THAT FREQUENTLY PERSISTS, DESPITE TREATMENT, DUE TO AN INDIVIDUAL'S UNDERLYING PSYCHOLOGICAL, NEUROBIOLOGICAL, AND GENETIC VULNERABILITIES. EVIDENCE SUGGESTS THAT THESE VULNERABILITIES MAY HAVE NEUROCHEMICAL, CELLULAR, AND MOLECULAR BASES. KEY NEUROPLASTIC EVENTS WITHIN THE MESOCORTICOLIMBIC SYSTEM THAT EMERGE THROUGH CHRONIC EXPOSURE TO OPIOIDS MAY HAVE A DETERMINATIVE INFLUENCE ON BEHAVIORAL SYMPTOMS ASSOCIATED WITH OUD. IN PARTICULAR, STRUCTURAL AND FUNCTIONAL ALTERATIONS IN THE DENDRITIC SPINES OF MEDIUM SPINY NEURONS (MSNS) WITHIN THE NUCLEUS ACCUMBENS (NAC) AND ITS DOPAMINERGIC PROJECTIONS FROM THE VENTRAL TEGMENTAL AREA (VTA) ARE BELIEVED TO FACILITATE THESE BEHAVIORAL SEQUELAE. ADDITIONALLY, GLUTAMATERGIC NEURONS FROM THE PREFRONTAL CORTEX, THE BASOLATERAL AMYGDALA, THE HIPPOCAMPUS, AND THE THALAMUS PROJECT TO THESE SAME MSNS, PROVIDING AN ENRICHED TARGET FOR SYNAPTIC PLASTICITY. HERE, WE REVIEW LITERATURE RELATED TO NEUROADAPTATIONS IN NAC MSNS FROM DOPAMINERGIC AND GLUTAMATERGIC PATHWAYS IN OUD. WE ALSO DESCRIBE NEW FINDINGS RELATED TO TRANSCRIPTIONAL, EPIGENETIC, AND MOLECULAR MECHANISMS IN MSN PLASTICITY IN THE DIFFERENT STAGES OF OUD. 2021 10 6775 31 [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 11 1091 38 COGNITIVE ENHANCERS AS A TREATMENT FOR HEROIN RELAPSE AND ADDICTION. HEROIN ADDICTION IS A DISORDER THAT STEMS FROM MALADAPTIVE PLASTICITY WITHIN NEURAL CIRCUITS AND PRODUCES BROAD COGNITIVE DEFICITS. DESPITE CONSIDERABLE ADVANCES IN PSYCHOTHERAPY AND PHARMACOTHERAPY FOR HEROIN RELAPSE AND ADDICTION, EFFECTIVE TREATMENTS FOR HEROIN USE DISORDER ARE STILL LACKING. INCREASING PRECLINICAL EVIDENCE INDICATES THAT HEROIN SEEKING BEHAVIOR IS PERSISTENT AFTER WITHDRAWAL, WHILE COGNITIVE DYSFUNCTIONS ASSOCIATED WITH CHRONIC HEROIN USE ARE AN IMPORTANT CONTRIBUTING FACTOR TO RISK OF HEROIN RELAPSE AND ADDICTION. COGNITIVE ENHANCERS MAY BE USED TO STIMULATE TREATMENT SUCCESS AND ENHANCE TREATMENT EFFICACY. THE PURPOSE OF THIS REVIEW IS TO OUTLINE THE LITERATURE THAT DEMONSTRATES THE COGNITIVE DEFICITS DURING THE DEVELOPMENT OF HEROIN ADDICTION AND WITHDRAWAL PROCESS, AND SEVERAL FACTORS THAT UNDERLINE THE EFFICACY OF COGNITIVE ENHANCERS FOR HEROIN USE DISORDERS. THE REVIEW, THEN, EXAMINES THE POTENTIAL USE AND PHARMACOLOGICAL MECHANISMS OF COGNITIVE ENHANCERS THAT ACT ON CHOLINERGIC, GLUTAMATERGIC, DOPAMINERGIC OR ADRENERGIC PATHWAYS. IT ALSO EXAMINES THE EFFECTS OF COMPOUNDS THAT ALTER CREB SIGNALING AND EPIGENETIC MECHANISMS IN ANIMAL MODEL OF HEROIN RELAPSE. THE CURRENT BODY OF RESEARCH REVEALS THE NEW INSIGHTS INTO THE PHARMACOLOGICAL MECHANISMS UNDERLYING HEROIN ADDICTION AND HOLDS A SIGNIFICANT PROMISE FOR COGNITIVE ENHANCERS AS AN IMPROVED APPROACH TO TREAT HEROIN USE DISORDER IN A MORE EFFICIENT AND PERSISTENT WAY. 2019 12 189 34 ACETYL-L-CARNITINE IN CHRONIC PAIN: A NARRATIVE REVIEW. ACETYL-L-CARNITINE (ALC) IS AN ENDOGENOUS MOLECULE THAT NOT ONLY PLAYS A ROLE IN ENERGY METABOLISM, BUT ALSO HAS ANTIOXIDANT PROPERTIES, PROTECTS FROM OXIDATIVE STRESS, MODULATES BRAIN NEUROTRANSMITTERS SUCH AS ACETYLCHOLINE, SEROTONIN AND DOPAMINE, AND ACTS ON NEUROTROPHIC FACTORS SUCH AS NERVE GROWTH FACTOR (NGF) AND METABOTROPIC GLUTAMATE (MGLU) RECEPTORS BY MEANS OF EPIGENETIC MECHANISMS. IMPORTANTLY, IT INDUCES MGLU2 EXPRESSION AT NERVE TERMINALS, THUS GIVING RISE TO ANALGESIA AND PREVENTING SPINAL SENSITISATION. IT HAS ALSO BEEN FOUND TO HAVE EVEN LONG-TERM NEUROTROPHIC AND ANALGESIC ACTIVITY IN EXPERIMENTAL MODELS OF CHRONIC INFLAMMATORY AND NEUROPATHIC PAIN. THE AIM OF THIS NARRATIVE REVIEW IS TO SUMMARISE THE CURRENT EVIDENCE REGARDING THE USE OF ALC IN PATIENTS WITH CHRONIC PAIN, AND COGNITIVE AND MOOD DISORDERS, AND INVESTIGATE THE RATIONALE UNDERLYING ITS USE IN PATIENTS WITH FIBROMYALGIA SYNDROME, WHICH IS CHARACTERISED BY NOCIPLASTIC CHANGES THAT INCREASE THE SENSITIVITY OF THE NERVOUS SYSTEM TO PAIN. 2021 13 1651 36 DOPAMINE AND GLUCOSE, OBESITY, AND REWARD DEFICIENCY SYNDROME. OBESITY AS A RESULT OF OVEREATING AS WELL AS A NUMBER OF WELL DESCRIBED EATING DISORDERS HAS BEEN ACCURATELY CONSIDERED TO BE A WORLD-WIDE EPIDEMIC. RECENTLY A NUMBER OF THEORIES BACKED BY A PLETHORA OF SCIENTIFICALLY SOUND NEUROCHEMICAL AND GENETIC STUDIES PROVIDE STRONG EVIDENCE THAT FOOD ADDICTION IS SIMILAR TO PSYCHOACTIVE DRUG ADDICTION. OUR LABORATORY HAS PUBLISHED ON THE CONCEPT KNOWN AS REWARD DEFICIENCY SYNDROME (RDS) WHICH IS A GENETIC AND EPIGENETIC PHENOMENA LEADING TO IMPAIRMENT OF THE BRAIN REWARD CIRCUITRY RESULTING IN A HYPO-DOPAMINERGIC FUNCTION. RDS INVOLVES THE INTERACTIONS OF POWERFUL NEUROTRANSMITTERS AND RESULTS IN ABNORMAL CRAVING BEHAVIOR. A NUMBER OF IMPORTANT FACTS WHICH COULD HELP TRANSLATE TO POTENTIAL THERAPEUTIC TARGETS ESPOUSED IN THIS FOCUSED REVIEW INCLUDE: (1) CONSUMPTION OF ALCOHOL IN LARGE QUANTITIES OR CARBOHYDRATES BINGING STIMULATES THE BRAIN'S PRODUCTION OF AND UTILIZATION OF DOPAMINE; (2) IN THE MESO-LIMBIC SYSTEM THE ENKEPHALINERGIC NEURONS ARE IN CLOSE PROXIMITY, TO GLUCOSE RECEPTORS; (3) HIGHLY CONCENTRATED GLUCOSE ACTIVATES THE CALCIUM CHANNEL TO STIMULATE DOPAMINE RELEASE FROM P12 CELLS; (4) A SIGNIFICANT CORRELATION BETWEEN BLOOD GLUCOSE AND CEREBROSPINAL FLUID CONCENTRATIONS OF HOMOVANILLIC ACID THE DOPAMINE METABOLITE; (5) 2-DEOXYGLUCOSE (2DG), THE GLUCOSE ANALOG, IN PHARMACOLOGICAL DOSES IS ASSOCIATED WITH ENHANCED DOPAMINE TURNOVER AND CAUSES ACUTE GLUCOPRIVATION. EVIDENCE FROM ANIMAL STUDIES AND FMRI IN HUMANS SUPPORT THE HYPOTHESIS THAT MULTIPLE, BUT SIMILAR BRAIN CIRCUITS ARE DISRUPTED IN OBESITY AND DRUG DEPENDENCE AND FOR THE MOST PART, IMPLICATE THE INVOLVEMENT OF DA-MODULATED REWARD CIRCUITS IN PATHOLOGIC EATING BEHAVIORS. BASED ON A CONSENSUS OF NEUROSCIENCE RESEARCH TREATMENT OF BOTH GLUCOSE AND DRUG LIKE COCAINE, OPIATES SHOULD INCORPORATE DOPAMINE AGONIST THERAPY IN CONTRAST TO CURRENT THEORIES AND PRACTICES THAT UTILIZES DOPAMINE ANTAGONISTIC THERAPY. CONSIDERING THAT UP UNTIL NOW CLINICAL UTILIZATION OF POWERFUL DOPAMINE D2 AGONISTS HAVE FAILED DUE TO CHRONIC DOWN REGULATION OF D2 RECEPTORS NEWER TARGETS BASED ON NOVEL LESS POWERFUL D2 AGONISTS THAT UP-REGULATE D2 RECEPTORS SEEMS PRUDENT. WE ENCOURAGE NEW STRATEGIES TARGETED AT IMPROVING DA FUNCTION IN THE TREATMENT AND PREVENTION OF OBESITY A SUBTYPE OF REWARD DEFICIENCY. 2014 14 4207 27 METABOTROPIC GLUTAMATE RECEPTORS AND THE CONTROL OF CHRONIC PAIN. OVER THE PAST TWO DECADES METABOTROPIC GLUTAMATE (MGLU) RECEPTOR LIGANDS HAVE BEEN INVESTIGATED FOR THEIR POTENTIAL THERAPEUTIC EFFECTS IN DIFFERENT DISORDERS OF THE CENTRAL NERVOUS SYSTEM (CNS), INCLUDING ANXIETY, DEPRESSION, SCHIZOPHRENIA, AND NEURODEGENERATIVE DISEASES. IN ADDITION, IT HAS BEEN WIDELY DEMONSTRATED THAT MGLU RECEPTORS ARE ABLE TO MODULATE PAIN TRANSMISSION BOTH IN INFLAMMATORY AND NEUROPATHIC PAIN MODELS. A LARGE NUMBER OF PRECLINICAL STUDIES COMBINING THE USE OF SELECTIVE LIGANDS WITH THE KNOCKOUT STRATEGY HAVE REVEALED MORE DETAILS ABOUT THE ROLE OF THE DIFFERENT MGLU RECEPTOR SUBTYPES IN THE MODULATION OF PAIN INFORMATION. THIS REVIEW WILL ADDRESS THE ROLE OF MGLU RECEPTORS IN PAIN SENSITIVITY FOCUSING ON DIFFERENT STRATEGIES TO ACHIEVE PAIN CONTROL BY TARGETING SPECIFIC MGLU RECEPTOR SUBTYPES. SPECIFICALLY, PHARMACOLOGICAL INTERVENTIONS AIMED AT INHIBITING GROUP I MGLU RECEPTOR-MEDIATED SIGNALING AND/OR POTENTIATING GROUPS II AND III MGLU RECEPTOR SIGNALING TOGETHER WITH AN EPIGENETIC APPROACH LEADING TO AN INCREASED EXPRESSION OF MGLU2 RECEPTORS WILL BE DISCUSSED. 2012 15 23 36 60 YEARS OF NEUROENDOCRINOLOGY: REDEFINING NEUROENDOCRINOLOGY: STRESS, SEX AND COGNITIVE AND EMOTIONAL REGULATION. THE DISCOVERY OF STEROID HORMONE RECEPTORS IN BRAIN REGIONS THAT MEDIATE EVERY ASPECT OF BRAIN FUNCTION HAS BROADENED THE DEFINITION OF 'NEUROENDOCRINOLOGY' TO INCLUDE THE RECIPROCAL COMMUNICATION BETWEEN THE BRAIN AND THE BODY VIA HORMONAL AND NEURAL PATHWAYS. THE BRAIN IS THE CENTRAL ORGAN OF STRESS AND ADAPTATION TO STRESS BECAUSE IT PERCEIVES AND DETERMINES WHAT IS THREATENING, AS WELL AS THE BEHAVIORAL AND PHYSIOLOGICAL RESPONSES TO THE STRESSOR. THE ADULT AND DEVELOPING BRAIN POSSESS REMARKABLE STRUCTURAL AND FUNCTIONAL PLASTICITY IN RESPONSE TO STRESS, INCLUDING NEURONAL REPLACEMENT, DENDRITIC REMODELING, AND SYNAPSE TURNOVER. STRESS CAUSES AN IMBALANCE OF NEURAL CIRCUITRY SUBSERVING COGNITION, DECISION-MAKING, ANXIETY AND MOOD THAT CAN ALTER EXPRESSION OF THOSE BEHAVIORS AND BEHAVIORAL STATES. THIS IMBALANCE, IN TURN, AFFECTS SYSTEMIC PHYSIOLOGY VIA NEUROENDOCRINE, AUTONOMIC, IMMUNE AND METABOLIC MEDIATORS. IN THE SHORT TERM, AS FOR INCREASED FEARFUL VIGILANCE AND ANXIETY IN A THREATENING ENVIRONMENT, THESE CHANGES MAY BE ADAPTIVE. BUT, IF THE DANGER PASSES AND THE BEHAVIORAL STATE PERSISTS ALONG WITH THE CHANGES IN NEURAL CIRCUITRY, SUCH MALADAPTATION MAY NEED INTERVENTION WITH A COMBINATION OF PHARMACOLOGICAL AND BEHAVIORAL THERAPIES, AS IS THE CASE FOR CHRONIC ANXIETY AND DEPRESSION. THERE ARE IMPORTANT SEX DIFFERENCES IN THE BRAIN RESPONSES TO STRESSORS THAT ARE IN URGENT NEED OF FURTHER EXPLORATION. MOREOVER, ADVERSE EARLY-LIFE EXPERIENCE, INTERACTING WITH ALLELES OF CERTAIN GENES, PRODUCE LASTING EFFECTS ON BRAIN AND BODY OVER THE LIFE-COURSE VIA EPIGENETIC MECHANISMS. WHILE PREVENTION IS MOST IMPORTANT, THE PLASTICITY OF THE BRAIN GIVES HOPE FOR THERAPIES THAT TAKE INTO CONSIDERATION BRAIN-BODY INTERACTIONS. 2015 16 5644 18 SEX AND THE MIGRAINE BRAIN. THE BRAIN RESPONDS DIFFERENTLY TO ENVIRONMENTAL AND INTERNAL SIGNALS THAT RELATE TO THE STAGE OF DEVELOPMENT OF NEURAL SYSTEMS. WHILE GENETIC AND EPIGENETIC FACTORS CONTRIBUTE TO A PREMORBID STATE, HORMONAL FLUCTUATIONS IN WOMEN MAY ALTER THE SET POINT OF MIGRAINE. THE CYCLIC SURGES OF GONADAL HORMONES MAY DIRECTLY ALTER NEURONAL, GLIAL AND ASTROCYTE FUNCTION THROUGHOUT THE BRAIN. ESTROGEN IS MAINLY EXCITATORY AND PROGESTERONE INHIBITORY ON BRAIN NEURONAL SYSTEMS. THESE CHANGES CONTRIBUTE TO THE ALLOSTATIC LOAD OF THE MIGRAINE CONDITION THAT MOST NOTABLY STARTS AT PUBERTY IN GIRLS. 2014 17 5149 32 PPAR AND FUNCTIONAL FOODS: RATIONALE FOR NATURAL NEUROSTEROID-BASED INTERVENTIONS FOR POSTPARTUM DEPRESSION. ALLOPREGNANOLONE, A GABAERGIC NEUROSTEROID AND PROGESTERONE DERIVATIVE, WAS RECENTLY APPROVED BY THE FOOD AND DRUG ADMINISTRATION FOR THE TREATMENT OF POSTPARTUM DEPRESSION (PPD). SEVERAL MECHANISMS APPEAR TO BE INVOLVED IN THE PATHOGENESIS OF PPD, INCLUDING NEUROENDOCRINE DYSFUNCTION, NEUROINFLAMMATION, NEUROTRANSMITTER ALTERATIONS, GENETIC AND EPIGENETIC MODIFICATIONS. RECENT EVIDENCE HIGHLIGHTS THE HIGHER RISK FOR INCIDENCE OF PPD IN MOTHERS EXPOSED TO UNHEALTHY DIETS THAT NEGATIVELY IMPACT THE MICROBIOME COMPOSITION AND INCREASE INFLAMMATION, ALL EFFECTS THAT ARE STRONGLY CORRELATED WITH MOOD DISORDERS. CONVERSELY, HEALTHY DIETS HAVE CONSISTENTLY BEEN REPORTED TO DECREASE THE RISK OF PERIPARTUM DEPRESSION AND TO PROTECT THE BODY AND BRAIN AGAINST LOW-GRADE SYSTEMIC CHRONIC INFLAMMATION. SEVERAL BIOACTIVE MICRONUTRIENTS FOUND IN THE SO-CALLED FUNCTIONAL FOODS HAVE BEEN SHOWN TO PLAY A RELEVANT ROLE IN PREVENTING NEUROINFLAMMATION AND DEPRESSION, SUCH AS VITAMINS, MINERALS, OMEGA-3 FATTY ACIDS AND FLAVONOIDS. AN INTRIGUING MOLECULAR SUBSTRATE LINKING FUNCTIONAL FOODS WITH IMPROVEMENT OF MOOD DISORDERS MAY BE REPRESENTED BY THE PEROXISOME-PROLIFERATOR ACTIVATED RECEPTOR (PPAR) PATHWAY, WHICH CAN REGULATE ALLOPREGNANOLONE BIOSYNTHESIS AND BRAIN-DERIVED NEUROTROPIC FACTOR (BDNF) AND THEREBY MAY REDUCE INFLAMMATION AND ELEVATE MOOD. HEREIN, WE DISCUSS THE POTENTIAL CONNECTION BETWEEN FUNCTIONAL FOODS AND PPAR AND THEIR ROLE IN PREVENTING NEUROINFLAMMATION AND SYMPTOMS OF PPD THROUGH NEUROSTEROID REGULATION. WE SUGGEST THAT HEALTHY DIETS BY TARGETING THE PPAR-NEUROSTEROID AXIS AND THEREBY DECREASING INFLAMMATION MAY OFFER A SUITABLE FUNCTIONAL STRATEGY TO PREVENT AND SAFELY ALLEVIATE MOOD SYMPTOMS DURING THE PERINATAL PERIOD. 2020 18 4420 24 MOLECULAR AND EPIGENETIC MECHANISMS FOR THE COMPLEX EFFECTS OF STRESS ON SYNAPTIC PHYSIOLOGY AND COGNITIVE FUNCTIONS. EVIDENCE OVER THE PAST DECADES HAS FOUND THAT STRESS, PARTICULARLY THROUGH THE CORTICOSTERONE STRESS HORMONES, PRODUCES COMPLEX CHANGES IN GLUTAMATERGIC SIGNALING IN PREFRONTAL CORTEX, WHICH LEADS TO THE ALTERATION OF COGNITIVE PROCESSES MEDICATED BY THIS BRAIN REGION. INTERESTINGLY, THE EFFECTS OF STRESS ON GLUTAMATERGIC TRANSMISSION APPEAR TO BE "U-SHAPED," DEPENDING UPON THE DURATION AND SEVERITY OF THE STRESSOR. THESE BIPHASIC EFFECTS OF ACUTE VS CHRONIC STRESS REPRESENT THE ADAPTIVE VS MALADAPTIVE RESPONSES TO STRESSFUL STIMULI. ANIMAL STUDIES SUGGEST THAT THE STRESS-INDUCED MODULATION OF EXCITATORY SYNAPTIC TRANSMISSION INVOLVES CHANGES IN PRESYNAPTIC GLUTAMATE RELEASE, POSTSYNAPTIC GLUTAMATE RECEPTOR MEMBRANE TRAFFICKING AND DEGRADATION, SPINE STRUCTURE AND CYTOSKELETON NETWORK, AND EPIGENETIC CONTROL OF GENE EXPRESSION. THIS REVIEW WILL DISCUSS CURRENT FINDINGS ON THE KEY MOLECULES INVOLVED IN THE STRESS-INDUCED REGULATION OF PREFRONTAL CORTEX SYNAPTIC PHYSIOLOGY AND PREFRONTAL CORTEX-MEDIATED FUNCTIONS. UNDERSTANDING THE MOLECULAR AND EPIGENETIC MECHANISMS THAT UNDERLIE THE COMPLEX EFFECTS OF STRESS WILL HELP TO DEVELOP NOVEL STRATEGIES TO COPE WITH STRESS-RELATED MENTAL DISORDERS. 2017 19 3092 28 GENOMIC AND EPIGENOMIC MECHANISMS OF GLUCOCORTICOIDS IN THE BRAIN. FOLLOWING THE DISCOVERY OF GLUCOCORTICOID RECEPTORS IN THE HIPPOCAMPUS AND OTHER BRAIN REGIONS, RESEARCH HAS FOCUSED ON UNDERSTANDING THE EFFECTS OF GLUCOCORTICOIDS IN THE BRAIN AND THEIR ROLE IN REGULATING EMOTION AND COGNITION. GLUCOCORTICOIDS ARE ESSENTIAL FOR ADAPTATION TO STRESSORS (ALLOSTASIS) AND IN MALADAPTATION RESULTING FROM ALLOSTATIC LOAD AND OVERLOAD. ALLOSTATIC OVERLOAD, WHICH CAN OCCUR DURING CHRONIC STRESS, CAN RESHAPE THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS THROUGH EPIGENETIC MODIFICATION OF GENES IN THE HIPPOCAMPUS, HYPOTHALAMUS AND OTHER STRESS-RESPONSIVE BRAIN REGIONS. GLUCOCORTICOIDS EXERT THEIR EFFECTS ON THE BRAIN THROUGH GENOMIC MECHANISMS THAT INVOLVE BOTH GLUCOCORTICOID RECEPTORS AND MINERALOCORTICOID RECEPTORS DIRECTLY BINDING TO DNA, AS WELL AS BY NON-GENOMIC MECHANISMS. FURTHERMORE, GLUCOCORTICOIDS SYNERGIZE BOTH GENOMICALLY AND NON-GENOMICALLY WITH NEUROTRANSMITTERS, NEUROTROPHIC FACTORS, SEX HORMONES AND OTHER STRESS MEDIATORS TO SHAPE AN ORGANISM'S PRESENT AND FUTURE RESPONSES TO A STRESSFUL ENVIRONMENT. HERE, WE DISCUSS THE MECHANISMS OF GLUCOCORTICOID ACTION IN THE BRAIN AND REVIEW HOW GLUCOCORTICOIDS INTERACT WITH STRESS MEDIATORS IN THE CONTEXT OF ALLOSTASIS, ALLOSTATIC LOAD AND STRESS-INDUCED NEUROPLASTICITY. 2017 20 6097 13 THE EFFECTS OF STRESS ON GLUTAMATERGIC TRANSMISSION IN THE BRAIN. STRESS LEADS TO DETRIMENTAL EFFECTS ON BRAIN FUNCTIONS AND RESULTS IN VARIOUS DISEASES. RECENT STUDIES HIGHLIGHT THE INVOLVEMENT OF GLUTAMATERGIC TRANSMISSION IN PATHOGENESIS OF DEPRESSIVE BEHAVIORS AND FEARS. ACUTE STRESS GENERATES DIFFERENT IMPACTS ON THE EXCITATORY TRANSMISSION COMPARED TO CHRONIC STRESS. DIFFERENT NEUROMODULATORS AND EPIGENETIC FACTORS ALSO PARTICIPATE IN THE ALTERATION OF SYNAPTIC TRANSMISSION AND THE REGULATION OF SYNAPTIC PLASTICITY. RESTORATION OF THE GLUTAMATERGIC TRANSMISSION IN STRESS-AFFECTED BRAIN AREAS THEREFORE PROVIDES NOVEL DIRECTIONS OF THERAPEUTIC INTERVENTIONS AGAINST STRESS. 2015