Central inhibition of sexual response in the male: a theoretical perspective

A theoretical model for central inhibition of sexual response is proposed, postulating individual variability in the propensity for such inhibition. Whereas such inhibition is typically adaptive, individuals with high propensity may be vulnerable to sexual dysfunction, and those with low propensity to high risk sexual behavior. Evidence of the existence and localization of such inhibitory mechanisms from both the animal and human literature is reviewed. Evidence of central neurotransmitters with sexual inhibitory effects is substantial, though in most cases the inhibition is not specific to sexual response or behavior. Recent studies have identified centers in the brain stem and lateral hypothalamus which appear to have specific inhibitory effects on sexual response. A variety of adaptive mechanisms involving inhibition of sexual response are considered, some involving perception of threat, others occurring more directly as consequences of previous sexual activity. These different adaptive functions may well involve different inhibitory mechanisms. This theoretical model opens a new agenda for experimental research into adaptive sexual behavior, both human and animal.