A model for the study of sexual function in anesthetized male and female rats.

A preparation for the study of sexual function in anesthetized spinal male and female rats is discussed. Urethral stimulation in males elicited penile erection, ejaculation, and rhythmic contractions of the striated perineal muscles. In females, vaginal and uterine contractions and rhythmic contractions of the perineal muscles were elicited. These responses show many similarities to responses seen during sexual climax in unanesthetized humans and animals. This response, which we refer to as the urethrogenital reflex, is unaffected in either sex by gonadectomy. We determined that the urethrogenital reflex is produced by a spinal pattern generator and is under tonic descending inhibition from the brain stem. We conclude that this preparation may be a valuable model for experimental study of the neural mechanisms of sexual function in both sexes.