THE MEDIATION OF FELINE ERECTION THROUGH SYMPATHETIC PATHWAYS WITH SOME REMARKS ON SEXUAL BEHAVIOR AFTER DEAFFERENTATION OF THE GENITALIA

Abstract

After removal of the lower segments of the spinal cord, 21 male cats were tested repeatedly over periods of wks. Each regularly developed full erections when they attempted to mount estrous females. In every case the 3 sacral segments, from which the nervi erigentes originate, had been removed, and in the majority the 2 lowermost lumbar segments as well. In some, the extirpation extended upwards to include the 5th or 4th lumbar segment. Six of the animals with lumbosacral removals were later subjected to cord transections at various upper lumbar or lower thoracic levels. The results showed that the suprasacral vasodilator (erector) outflow to the penis is composed of fibers which originate chiefly from the 2d, 3d, and 4th lumbar spinal segments. That the pathway runs through the lumbar portions of the abdominal sympathetic chains and reaches the pelvis, in most cases, by way of the inferior mesenteric ganglia and hypogastric nerves was shown by combining one or another sympathectomy with ablation of the lower spinal segments. With the spinal cord intact, removal of the abdominal sympathetic chains produced no disorder of the sexual activities and behavior of male cats except failure to ejaculate (actually failure of emission). Exclusion of afferent impulses from the genital organs and indeed from the whole pelvic region and tail, including wide skin areas around the external genitalia, did not affect the sexual aggressiveness of male cats.