Low and moderate doses of acute ethanol do not impair spatial cognition but facilitate accelerating rotarod performance in adolescent and adult rats

Abstract

Adolescents and adult rodents have differing sensitivities to the acute effects of ethanol on a variety of behavioral and electrophysiological measures. Often, these differences are revealed using high ethanol doses and consequently little is known about these age-related effects using lower ethanol doses. We sought to determine if low-dose ethanol produces differential effects on cognition and motor behavior in adolescent and adult rats. Adolescent (postnatal day PD 30-32) and adult (PD 70-72) male Sprague Dawley rats were trained on the standard version of the Morris Water Maze (MWM) for 5 days or received 5 training trials on an accelerating rotarod (ARR). Adolescents learned the location of the submerged platform in the MWM significantly slower than adults during training and, acute ethanol administration (0.5 g/kg, 0.75 g/kg, or 1.0 g/kg) 30 min before testing did not impair spatial memory in either age group. On the ARR test, adolescent rats spent significantly more time on the rotarod compared to adults and, alcohol exposure (1.0 g/kg) significantly increased ARR performance 30 min following administration. Our findings address the utility of investigating low and moderate doses of ethanol during different developmental stages in rats.