SPECIFIC INVOLVEMENT OF CENTRAL 5-HT1A RECEPTORS IN THE MEDIATION OF MALE-RAT EJACULATORY BEHAVIOR

The aminotetralin 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), pharmacologically characterized as a 5-HT1A receptor agonist, produces a pronounced decrease in ejaculation latency in the male rat. Stimula tion of 5-HT receptors by a pharmacologically induced increase in the synaptic availability of 5-HT has been shown to produce the opposite e ffect. The 8-OH-DPAT-induced decrease in ejaculation latency is specif ic for this compound, and some chemically related ergot derivatives. I n this paper we review the evidence in support for stimulation of sero tonergic autoreceptors of the 5-HT1A receptor subtype as a mechanism o f action for effects by 8-OH-DPAT on male rat ejaculatory behavior. We also present the questions posed by the fact that quinpirole and lisu ride both produce 8-OH-DPAT-like effects on male rat ejaculatory behav ior. The effects by quinpirole, lisuride or 8-OH-DPAT are not sensitiv e to pretreatment with the DA D-2/3 receptor antagonist raclopride. Co ntinued studies will show whether the effects of quinpirole and lisuri de can be related to stimulation of 5-HT1A receptors, or if all these compounds have as yet undefined common properties.