SEXUAL-BEHAVIOR IN MALE RATS AFTER RADIOFREQUENCY OR DOPAMINE-DEPLETING LESIONS IN NUCLEUS-ACCUMBENS

Considerable neurochemical evidence links dopamine (DA) in nucleus acc umbens (NAcc) to male sexual behavior. The present experiments were co nducted to extend this information to the male's sexual response to re mote stimuli from estrous female (noncontact erection; NCE). Male rats were tested for copulation and NCE after either 6-hydroxydopamine (6- OHDA) or radiofrequency (RF) lesions in NAcc). Males with an average 7 8% depletion of DA in NAcc had a lower incidence of NCE, longer latenc y to display NCE, and fewer erections. DA-depleted males also had less locomotor activity after injections of d-amphetamine, and reductions in apomorphine-induced yawning, but a normal incidence of penile erect ion. Males with RF lesions of the NAcc had longer NCE latencies. All m ales copulated to ejaculation after either 6-OHDA or RF lesions with l ittle or no deficit, although the 6-OHDA-treated males had longer intr omission latencies. The NCE deficit supports the hypothesized role of NAcc DA in arousal processes in responding to remote cues from estrous females. The minimal effect of lesions on copulation suggests that th e presence of additional proximal stimulation during copulation may ov ercome the deficits induced by DA depletions or lesions in NAcc. (C) 1 998 Elsevier Science Inc.