Central neurophysiology and dopaminergic control of ejaculation

Although premature ejaculation (PE) represents the most common male sexual dysfunction, brain mechanisms controlling ejaculatory process remain poorly understood. Recently a group of neurons, identified in the lumbar spinal cord, has been proposed to constitute a spinal ejaculation generator. This key site in ejaculation control, relaying sensory inputs to the brain, is under supraspinal excitatory (medial preoptic area, paraventricular nucleus of the hypothalamus) and inhibitory (nucleus paragigantocellularis) controls. Activation of brain excitatory areas by dopamine (DA) or DA agonists being demonstrated to facilitate ejaculation, it seems particularly interesting to further understand the implication of central DA in the complex process leading to ejaculation. Moreover, the fact that dopaminergic pathways are involved in sexual behavior and that DA release in some brain regions is an important facilitator of male sexual behavior reinforces the crucial implication of DA. Clearly, a better understanding of DA incerto-hypothalamic pathways and targeting brain DA receptor subtypes mediating ejaculation (especially D(3) receptors) will benefit the development of new pharmacological strategies to treat ejaculatory dysfunction including PE.