Ethanol consumption improves avoidance learning in rats: role of deprivation interval

Voluntary oral self-administration of ethanol in rats has been used to model ethanol consumption and abuse in human beings, with contradictory results. The purpose of the current study was to assess the effect of voluntary ethanol consumption on acquisition of a lever press escape/avoidance task in rats. Male Wistar rats were exposed to ethanol in a limited-access procedure, and either 1 day or 10 days after their last ethanol exposure, animals received a 4-h lever press escape/avoidance session. Control animals were not exposed to ethanol at any time. Animals in the 1-day ethanol-deprivation group performed significantly better than did the other two groups with respect to avoidance responding. There were no group differences in number of lever presses during a safety period, a measure of anxiety. Further, we obtained a significant negative correlation between behavioral performance and change in ethanol consumption after the escape/avoidance session, as well as a significant positive correlation between baseline ethanol consumption and avoidance performance. Results are discussed in terms of the potential neural mediators of the improved avoidance effect in animals in the 1-day ethanol-deprivation group. (c) 2005 Elsevier Inc. All rights reserved.