Neurophysiologic maps of cutaneous innervation of the hind limb of sheep

The area of skin supplied by afferent fibers in a peripheral nerve is called the cutaneous area (CA) of that nerve. The CA of hind limb nerves that were responsive to movement of wool/hairs were mapped neurophysiologically in 25 barbiturate-anesthetized sheep. The CA of the dorsal cutaneous branches of the caudal lumbar spinal nerves and of the sacral spinal nerves extended over the lateral aspect of the thigh. The CA of the lateral cutaneous femoral nerve was restricted to the stifle region, that of the saphenous nerve did not reach the digits, that of the deep peroneal nerve lay between the 3rd and 4th digits, and that of the lateral plantar nerve was confined to the lateral aspect of the 4th digit. The CA of the superficial peroneal nerve enveloped the dorsal, medial, and lateral aspects of the distal portions of the hind limb. In some sheep, the boundaries of the CA of the superficial peroneal nerve were juxtaposed caudally in such way that the medial plantar nerve did not have an autonomous zone. Differences in sizes of the CA resulted in corresponding differences in the overlap between adjacent CA and concomitant differences in the sizes of autonomous zones.