Influence of ACTH1-24 on grooming and sociosexual behavior in the rat.

The effects of intraventricular administration of ACTH 1-24 on grooming, exploratory and socio-sexual behaviors in male rats were studied. The various behavioral elements were analyzed in terms of latency, frequency, and duration, which provided a multivariate behavioral profile. Behaviors that occur early during the test procedure had decreased, whereas behaviors displayed after the animal had spent some time in the test situation increased. Sociability, sexual approaches, and sexual preference in a sociosexual test situation were not altered by this treatment. The extinction of the response after removal of the incentive animals was delayed, however. It is concluded that ACTH1-24 did not specifically influence goal-directed behaviors. The obtained change in the behavioral profile, including the grooming pattern, rather suggest that ACTH1-24 affects mechanisms associated with attention and habituation.