Repeated moderate-dose ethanol bouts impair cognitive function in Wistar rats

The effects of repeated, intermittent administration of a moderate dose of ethanol (3.4 g/kg/day x 6 days, intragastrically via gavages) on cognitive function were examined in male Wistar rats. No significant differences in weight gain between the ethanol- and water-treated rats were found. Analysis of physical dependence revealed no signs of spontaneous withdrawal, whereas withdrawal signs exacerbated by Ro15-4513, an inverse benzodiazepine agonist, were apparent 5 hours but not 24 hours after the cessation of ethanol treatment. Spatial learning and memory, as assessed in the Barnes maze, were impaired 36 days following the treatment but recovered by the 11th14th days. Reversal learning, however, was impaired throughout the 2-week observation period. Thus, bouts of moderate-dose ethanol administration transiently impair spatial learning and memory, and promote cognitive inflexibility. The employed ethanol exposure paradigm may provide a model of human cognitive deficits associated with alcohol binge drinking.