Differential effects of a new serotoninomimetic drug, 8-OH-DPAT, on copulatory behavior and pelvic thrusting pattern in the male rat.

Treatment of sexually experienced male rats with 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), a new drug having central serotoninomimetic activity, caused a dose-dependent decrease in the number of mounts and intromissions to ejaculation and shortened the ejaculation latency. These changes in the coital pattern were not accompanied by any marked changes in the organization of the thrusting pattern. It was concluded that treatment with 8-OH-DPAT may influence the excitability of the central neural circuits determining the elicitation of ejaculation without affecting those involved in the pelvic thrusting pattern, despite evidence of general motor disturbances.