[Effect of oxytocin and its antagonist microinjected into the hippocampus on the intravenous self-administration of heroin in rats].

The paper deals with the effect of oxytocin (OXT) and its antagonist--oxytocin antiserum (ANT) microinjected in the ventral hippocampus--on learning of heroin intravenous self-administration in rats. OXT weakened the processes of heroin self-administration, while ANT in contrast improved the learning. The results of the study and data analysis suggest that endogenous OXT in the ventral hippocampus is involved in the mechanisms of behavioural reactions.