Alcohol self-administration by rats in the presence of a tangible object.

The authors used the sucrose-substitution procedure to train operant self-administration of a 10% alcohol solution in 8 Long-Evans rats. After they established stable responding, they began a 10-session baseline. A 10-session experimental phase followed the baseline phase. During the experimental phase, the authors placed a large glass marble in the center of the experimental chambers before self-administration sessions. The presence of the marble decreased the rats' responding and alcohol intake significantly. The authors discussed the results in terms of distraction and the effects of concurrently available reinforcers on alcohol self-administration.