The organization of saphenous nerve fibers in the dorsal roots of the rabbit and cat.

Electrophysiological experiments have been carried out on rabbits and cats to find out whether there is a relationship between the dorsal rootlet by which a particular saphenous nerve fiber passes to the spinal cord and the part of the saphenous nerve territory it supplies. Preliminary experiments were carried out to determine the extent of the saphenous nerve field in both animals and to determine the dorsal rootlets by which saphenous nerve fibers reach the cord in rabbits. Then, in experiments on rabbits and cats in which recordings were made from fiber bundles dissected from dorsal rootlets, it was found that saphenous nerve fibers in any one dorsal rootlet supplied only a limited portion of the saphenous nerve field; that there was overlap in the areas of the saphenous nerve field supplied by adjacent rootlets; and that moving caudo-rostrally through the rootlets containing saphenous fibers, the areas of skin supplied gradually moved from distal parts of the field to proximal ones. The results show that the saphenous nerve input to the spinal cord is somatotopically organized.