Anti-anxiety Self-medication Induced by Incentive Loss in Rats

Ethanol can be used to ameliorate negative emotion in anxiety-inducing situations. Two experiments tested whether rats would increase preference for ethanol immediately after anxiogenic sessions of appetitive extinction. It was predicted that preference for ethanol would be greater in inbred Roman low-avoidance rats (RLA-I) than in inbred Roman high-avoidance rats (RHA-I), given previous research demonstrating that the former strain exhibits greater sensitivity to incentive loss. Experiment 1 used a consummatory extinction task (22-to-0% sucrose downshift), whereas Experiment 2 used an instrumental extinction task (12-to-0 pellet downshift). In both experiments, postsession ethanol consumption was higher in RLA-I rats than in RHA-I rats. No strain differences in ethanol preference were found after acquisition sessions or in groups given postsession access to water. Because ethanol is an anti-anxiety drug, the present results suggest that rats are capable of changing their consummatory behavior to correct for an aversive emotional state induced by incentive loss.