8-OH-DPAT AND MALE-RAT SEXUAL-BEHAVIOR - PARTIAL BLOCKADE BY NORADRENERGIC LESION AND SEXUAL EXHAUSTION

As previously shown, the 5-HT1A agonist 8-OH-DPAT is a potent facilita tor of male rat copulatory behavior in both sexually experienced and s exually exhausted male rats. The basis of the facilitation is still no t clear. Therefore, the purpose of the present study was to determine whether 8-OH-DPAT-induced sexual-behavior facilitation could be conter acted by lesioning the NA system with the noradrenergic neurotoxin DSP 4 In NA-lesioned, sexually experienced, non-exhausted rats, the facili tatory effects of 8-OH-DPAT on the number of mounts and the postejacul atory interval were reduced, the effect on the intromission latency di sappeared, while the percentage of copulating rats was not significant ly altered. In sexually exhausted rats bearing a lesion of the NA syst em, the facilitatory effects of 8-OH-DPAT on the percentage of copulat ing rats was blocked. Data are discussed on the basis of the interacti ons between the noradrenergic and serotonergic systems in the mediatio n of the facilitatory effect of 8-OH-DPAT in sexually exhausted and no n-exhausted rats