Immunohistochemical evidence for the interaction between levator ani and pudendal motor neurons in the coordination of pelvic floor and visceral activity in the squirrel monkey

The LA muscle has a distinct innervation with very little or no contribution from the pudendal nerve. The intriguing labeling of LA neural elements within a nucleus that innervates the external urethral and anal sphincters (involved in pelvic visceral control) may represent a neuroanatomic substrate for physiologic integration of spinal and supraspinal inputs for the coordination of pelvic floor and visceral activity.