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 facilitator of male rat copulatory behavior in both sexually experienced and sexually exhausted male rats. The basis of the facilitation is still not clear. Therefore, the purpose of the present study was to determine whether 8-OH-DPAT-induced sexual-behavior facilitation could be conteracted by lesioning the NA system with the noradrenergic neurotoxin DSP4 In NA-lesioned, sexually experienced, non-exhausted rats, the facilitatory effects of 8-OH-DPAT on the number of mounts and the postejaculatory interval were reduced, the effect on the intromission latency disappeared, while the percentage of copulating rats was not significantly altered. In sexually exhausted rats bearing a lesion of the NA system, the facilitatory effects of 8-OH-DPAT on the percentage of copulating rats was blocked. Data are discussed on the basis of the interactions between the noradrenergic and serotonergic systems in the mediation of the facilitatory effect of 8-OH-DPAT in sexually exhausted and non-exhausted rats