Project Grant F31AA032988

INVESTIGATING THE ROLES, PROPERTIES, AND SIGNALING DYNAMICS OF CENTRAL AMYGDALA NEUROTENSIN NEURONS IN ALCOHOL USE DISORDER - ABSTRACT ALCOHOL IS THE MOST WIDELY USED PSYCHOACTIVE DRUG IN THE WORLD WITH WIDESPREAD HEALTH AND SOCIETAL IMPACTS. DESPITE HIGH CONSUMPTION RATES, ONLY ~10% OF INDIVIDUALS WHO DRINK IN THE US SUBSEQUENTLY DEVELOP ALCOHOL USE DISORDERS (AUD). FOR THOSE THAT HAVE AUD, TREATMENTS REMAIN LIMITED IN NUMBER AND EFFICACY. NEUROTENSIN (NTS) IS A NEUROPEPTIDE THAT HAS EMERGED AS A POTENTIAL THERAPEUTIC FOR REDUCING ALCOHOL USE, BUT THE MECHANISMS BEHIND NEUROTENSINERGIC SIGNALING THAT MEDIATE CHANGES IN ALCOHOL DRINKING REMAIN LARGELY UNEXPLORED. THIS RESEARCH PROPOSAL INVESTIGATES THE ROLE OF NTS SIGNALING IN THE CENTRAL AMYGDALA (CEA) AS A SYSTEM UNDERLYING ALCOHOL DRINKING AND ITS POTENTIAL AS A THERAPEUTIC TARGET FOR MITIGATING ALCOHOL MISUSE. THE CEA IS A HIGHLY INTERCONNECTED GABAERGIC REGION INVOLVED IN CONSUMPTION, AVOIDANCE, AND VALENCE PROCESSING. THE CEA SHOWS ELEVATED ACTIVATION DURING PERIODS OF ALCOHOL WITHDRAWAL, AND BOTH THE CEA AND ITS DOWNSTREAM TARGET, THE BED NUCLEUS OF THE STRIA TERMINALIS (BNST), EXHIBIT INCREASED ACTIVITY DURING PERIODS OF ALCOHOL DRINKING. WITHIN THE CEA, OUR LAB HAS DEMONSTRATED NTS AS A KEY MEDIATOR OF ALCOHOL CONSUMPTION: ABLATION OF NTS FROM THE CEA DECREASES ALCOHOL DRINKING, AS DOES KNOCKDOWN OF GABA FROM NTSCEA NEURONS IN A SEX-DEPENDENT MANNER. FURTHERMORE, PHARMACOLOGICAL MODULATION OF THE NTS SYSTEM VIA SBI-553, A B-ARRESTIN BIASED ALLOSTERIC MODULATOR OF NTSR1, REDUCES ALCOHOL CONSUMPTION IN DRINKING-IN-THE-DARK TASKS. YET HOW NTSCEA SIGNALING IS ALTERED ACROSS DIFFERENT PATTERNS OF ALCOHOL DRINKING AND THE CELLULAR AND CIRCUIT-LEVEL MECHANISMS BY WHICH SBI-553 REDUCES ALCOHOL CONSUMPTION HAVE NOT BEEN CHARACTERIZED. TO FURTHER ELUCIDATE THE ROLE OF THE NEUROTENSINERGIC SYSTEM IN HEIGHTENED ALCOHOL USE, I WILL UTILIZE A NOVEL PARADIGM WHICH I PREVIOUSLY DEVELOPED: THE STRUCTURED TRACKING OF ALCOHOL REINFORCEMENT (STAR). STAR IS A FRAMEWORK DESIGNED TO ASSESS THE INDIVIDUAL DEVELOPMENT OF ALCOHOL CONSUMPTION AND AVERSION-RESISTANT DRINKING (COMPULSION, A HALLMARK OF AUD) THROUGH OPERANT CONDITIONING. IN AIM 1, WHOLE-CELL PATCH-CLAMP ELECTROPHYSIOLOGY WILL BE USED TO INVESTIGATE HOW CEA INTRINSIC PROPERTIES ARE ALTERED BY ALCOHOL EXPOSURE AND HOW THESE CHANGES RELATE TO DRINKING PHENOTYPES ESTABLISHED THROUGH STAR. AIM 2 WILL EXAMINE HOW NTSR1 MODULATION WITH SBI-553 DIFFERENTIALLY ALTERS ALCOHOL CONSUMPTION ACROSS BEHAVIORAL PHENOTYPES AND HOW THESE CHANGES ARE REFLECTED AT THE CELLULAR LEVEL THROUGH IMMUNOHISTOCHEMISTRY. AIM 3 WILL EMPLOY FIBER PHOTOMETRY TO MONITOR IN VIVO CALCIUM DYNAMICS OF NTSCEA PROJECTIONS TO THE BNST OR PARABRACHIAL NUCLEUS (PBN; ANOTHER REGION THAT RECEIVES STRONG CEA NTS INPUT) DURING HOMECAGE ALCOHOL CONSUMPTION AT BASELINE AND FOLLOWING SBI- 553 TREATMENT. TOGETHER, THESE STUDIES AIM TO ESTABLISH A COHESIVE PICTURE OF HOW CELLULAR PROPERTIES AND CIRCUIT DYNAMICS IN THE CEA RELATE TO INDIVIDUAL DIFFERENCES IN ALCOHOL DRINKING AND COMPULSIVE-LIKE BEHAVIORS, AND HOW PHARMACOLOGICAL MODULATION OF THIS SYSTEM IMPACTS CONSUMPTION.