ABSTRACT
Penile erection is mediated by coordinated spinal activity in the autonomic pathways to the penis and in the somatic pathways to the perineal striated muscles. The process is initiated by the recruitment of afferent impulses, and after central processing and integration of tactile, visual, olfactory, and imaginative stimuli, the signals to the peripheral tissues involved are generated. This central regulation of penile erection (Fig. 1) involves many transmitters and transmitter systems, the details of which are still not completely known. Some of the anatomical areas of the brain that relate to sexual function have been defined, including the medial amygdala, medial preoptic area (MPOA), paraventricular nucleus (PVN), periaqueductal gray, and ventral tegmentum (1-3). Studies in rats have revealed that electrical stimulation of the MPOA (4), the PVN (5), or the hippocampal formation (6) can elicit an erectile response.
