Age-related effects of restraint stress on ethanol intake and ethanol-induced narcosis

PAUTASSI R.M; MS FERNÁNDEZ; NIZHNIKOV ME; SPEAR LP

Valencia

Congreso; 15t Meeting of the European Society for Biomedical Research on Alcoholism; 2015

European Society for Biomedical Research on Alcoholism

stress than adults, yet relatively little is known about age-related differencesin stress-induced ethanol drinking. Moreover, there is an ongoingcontroversy regarding the effects of restraint stress (RS), asapplied in preclinical animal models, upon ethanol intake. Thereare reports of RS increasing, decreasing or not affecting ethanol intake.We tested the hypothesis that chronic RS enhances ethanoldrinking in adolescent, but not in adult, male rats. In Experiment 1,adolescent and adult rats were given RS (5 daily sessions, duration:120 min) and then assessed for ethanol drinking in two-bottle choicetests. Stressed adolescents, but not stressed adults, drank more thantheir non-stressed counterparts. A subsequent experiment tested, inadolescent and adult rats exposed or not to chronic RS, sensitivityto ethanol-induced loss of righting reflex (LORR) and sleep time.Stress did not affect latency to LORR at any age. Adults exhibit significantlygreater ethanol-induced narcosis than adolescent rats, yetstress exposure reduced ethanol-induced narcosis time only in adults.These results indicate that adolescent rats are more prone than adultsto increase their ethanol drinking patterns after RS exposure. Stressreduced the narcotic effect of ethanol in the older animals, yet this?sobering? effect did not translate in greater ethanol intake. The resultsmeet the hypothesis that adolescents exhibit an idiosyncratic patternof response to ethanol, or to ethanol-stress interactions, that mayout them at risk for rapid transition from initiation to escalation ofethanol intake