The output of the hippocampus is inhibited during social behavior in the male rat.

During sexual behavior in the male rat, peptidergic cells in the medial amygdaloid nucleus become active and release a vasopressin-like peptide. The present experiments were designed to examine hippocampal changes as a result of this peptide's action during sexual behaviors. Chronic field-potential recordings from the hippocampus of male rats were acquired in a wide variety of social and nonsocial circumstances.