Ontogeny of functional innervation of bulbocavernosus muscles in male and female rats.

Electrical stimulation of the sixth lumbar ventral root reliably elicited contractions of the bulbocavernosus muscle (BC) in untreated female rats on the day before birth. This functional contact indicates that testosterone probably does not act to save the spinal nucleus of the bulbocavernosus (SNB) and its BC target muscles through the establishment of an active neuromuscular synapse, since this is already present in animals with an SNB system which is fated to die.