RESUMO
Preclinical and clinical evidence suggests that exogenous administration of oxytocin (OT) may hold promise as a therapeutic strategy for reducing heavy alcohol drinking. However, it remains unknown whether these effects are mediated by stimulation of endogenous sources of OT and signaling at oxytocin receptors (OTR) in brain or in the periphery. To address this question, we employed a targeted chemogenetic approach to examine whether selective activation of OT-containing neurons in the paraventricular nucleus of the hypothalamus (PVN) alters alcohol consumption in a binge-like drinking ("Drinking-in-the-Dark"; DID) model. Adult male Oxt-IRES-Cre mice received bilateral infusion of a Cre-dependent virus containing an excitatory DREADD (AAV8-hSyn-DIO-hM3Dq-mCherry) or control virus (AAV8-hSyn-DIO-mCherry) into the PVN. Chemogenetic activation of PVNOT+ neurons following clozapine-N-oxide injection reduced binge-like alcohol drinking in a similar manner as systemic administration of the neuropeptide. Pretreatment with a brain-penetrant OTR antagonist (L-368,899) reversed this effect while systemic administration of a peripherally restricted OTR antagonist (Atosiban) did not alter reduced alcohol drinking following chemogenetic activation of PVNOT+ neurons. Altogether, these data are the first to demonstrate that targeted activation of hypothalamic (endogenous) OT reduces alcohol consumption, providing further evidence that this neuropeptide plays a role in regulation of alcohol self-administration behavior. Further, results indicate that the ability OT to reduce alcohol drinking is mediated by signaling at OTR in the brain.
Assuntos
Consumo Excessivo de Bebidas Alcoólicas , Ocitocina , Receptores de Ocitocina , Animais , Hipotálamo/metabolismo , Masculino , Camundongos , Neurônios/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Receptores de Ocitocina/metabolismoRESUMO
INTRODUCTION: Some anticonvulsants ameliorate signs and symptoms of alcohol withdrawal, but have an unacceptable side effect burden. Among the advantages of using anticonvulsant agents in this capacity is their purported lack of interaction with alcohol that could increase psychomotor deficits, increase cognitive impairment, or increase intoxication. The aim of this study was to evaluate alcohol use and symptom reduction of gabapentin when compared with lorazepam in the treatment of alcohol withdrawal in a double-blinded randomized clinical trial. METHODS: One hundred individuals seeking outpatient treatment of alcohol withdrawal with Clinical Institute Withdrawal Assessment for Alcohol-Revised (CIWA-Ar) ratings > or =10 were randomized to double-blind treatment with 2 doses of gabapentin (900 mg tapering to 600 mg or 1200 tapering to 800 mg) or lorazepam (6 mg tapering to 4 mg) for 4 days. Severity of alcohol withdrawal was measured by the CIWA-Ar on days 1 to 4 of treatment and on days 5, 7, and 12 post-treatment and alcohol use monitored by verbal report and breath alcohol levels. RESULTS: CIWA-Ar scores decreased over time in all groups; high-dose gabapentin was statistically superior but clinically similar to lorazepam (p = 0.009). During treatment, lorazepam-treated participants had higher probabilities of drinking on the first day of dose decrease (day 2) and the second day off medication (day 6) compared to gabapentin-treated participants (p = 0.0002). Post-treatment, gabapentin-treated participants had less probability of drinking during the follow-up post-treatment period (p = 0.2 for 900 mg and p = 0.3 for 1200 mg) compared to the lorazepam-treated participants (p = 0.55). The gabapentin groups also had less craving, anxiety, and sedation compared to lorazepam. CONCLUSIONS: Gabapentin was well tolerated and effectively diminished the symptoms of alcohol withdrawal in our population especially at the higher target dose (1200 mg) used in this study. Gabapentin reduced the probability of drinking during alcohol withdrawal and in the immediate postwithdrawal week compared to lorazepam.