BEHAVIORAL-EFFECTS INDUCED BY THE DOPAMINE D-3 AGONIST 7-OH-DPAT IN SEXUALLY-ACTIVE AND SEXUALLY-INACTIVE MALE-RATS

The present study investigates the effects induced by the putative DA D-3 agonist 7-OH-DPAT (0.1 and 1 mg/kg, s.c.) on: (1) the sexual behav ior of male rats, categorized on the basis of seven consecutive mating pre-tests as sexually-active (SA) and sexually-inactive (SI); and (2) stretching-yawning, penile erection, sedation and stereotyped behavio r of the same animals. The data obtained show that 7-OH-DPAT at both d oses modifies the copulatory pattern of SA rats, facilitating ejaculat ion mechanisms, but fails to increase the sexual drive of the animals as is evident from the ineffectiveness in SI rats. The second major fi nding is that the two groups of rats, which are markedly different as regards sexual typology, exhibit different behavioral responses to 7-O H-DPAT. Copyright (C) 1996 Elsevier Science Ltd.