Neurochemistry of male sexual behavior

Abstract

Steroid hormones regulate male sexual behavior, in part, by orchestrating the production and release of neurotransmitters in brain areas that control sexual motivation and copulatory performance. Major facilitative neurotransmitters are dopamine, glutamate, and, in some cases, norepinephrine. Serotonin, GABA, and opioid peptides provide primarily inhibitory influence, although low levels of some of these neurotransmitters, acting via specific receptor subtypes, may facilitate certain aspects of behavior. Other neuropeptides, including oxytocin, orexin/hypocretin, α-melanocyte stimulating hormone, gonadotropin releasing hormone, and galanin-like peptide may facilitate mating, whereas neuropeptide Y, prolactin, corticotropin releasing hormone, and angiotensin II may have inhibitory effects. Brain areas that are especially important for the control of male sexual behavior include the medial preoptic area, the medial amygdala, the paraventricular nucleus of the hypothalamus, the mesocorticolimbic dopamine tract, several midbrain and brainstem nuclei, and nuclei in the spinal cord that control the erectile and ejaculatory reflexes. Some dopaminergic and serotonergic receptor subtypes promote parasympathetically mediated erection, and other subtypes facilitate sympathetically mediated seminal emission and ejaculation. © 2007 Springer-Verlag US.