Effects of a fixed time schedule and body weight on ethanol self-administration.

Two experiments are reported. The first study showed that the patterns of ethanol acquisition using the schedule induced self-injection paradigm, are more similar to those of heroin than methadone or nicotine but dissimilar to that of d-amphetamine. The second study showed that ethanol intake once established was not maintained by removal of the schedule. The results also showed that schedule induced behavior may be stressful as indexed by a significant increase of plasma corticosterone levels.