Autotomy after nerve injury and its relation to spontaneous discharge originating in nerve-end neuromas

Following transection and ligation of the sciatic and saphenous nerves, rodents frequently scratch and bite their anesthetic foot (autotomy). Many authors have suggested that autotomy is related to uncomfortable paresthesias induced by abnormal afferent discharge known to be generated in myelinated afferents in nerve-end neuromas. We report that preventing the development of ectopic neuroma discharge in rats by treating the severed nerves with colchicine or vinblastine does not prevent, or even detectably reduce, autotomy directed toward the denervated hindlimb. We conclude that abnormal discharge in myelinated afferents is not necessary for the expression of autotomy following nerve injury in rats.