Electrostimulation and penile erection.

Electrostimulation was used to study the neuroanatomy and physiology of penile erection in dogs and monkeys. The canine spinal nuclei responsible for penile erection, identified by the retrograde horseradish peroxidase transport technique after verification of the cavernous nerves with neurostimulation, were mediolateral autonomic neurons at T12-L3 and S1-S3. The erection induced by electrostimulation of the cavernous nerves is the result of increased arterial flow, relaxation of cavernous muscles, and venous outflow restriction. Study of electrostimulation in dogs and monkeys is invaluable for the understanding of the complex neurophysiology of human penile erection.