Context is a trigger for relapse to alcohol

The environment in which alcohol consumption occurs may trigger later relapse in alcohol abusers. In this study we tested whether an alcohol-associated environment would induce alcohol-seeking behavior. Male rats were trained to lever press for oral alcohol reinforcement in a distinctive context. Responding was then extinguished in a context with different olfactory, visual and tactile properties. Placement of the rats back into the original context in which they self-administered alcohol induced, in the absence of alcohol availability, a significant increase in lever press responding on the alcohol lever as compared to extinction levels of responding. The ability of the alcohol context to support alcohol-seeking behavior was maintained over three weeks, with no significant diminution. A second group of rats was trained to lever press for sucrose reinforcement; this group also demonstrated context-dependent reinstatement, although the degree of reinstatement decreased over repeated tests, returning to extinction values after three weeks. These findings indicate that contextual conditioning has a long-term impact on ethanol-seeking behavior after ethanol withdrawal. This animal model may be useful to study the neural mechanisms underlying relapse induced by ethanol-associated contexts in humans.