SYMPATHECTOMY DOES NOT AFFECT THE EARLY ECTOPIC DISCHARGE FROM MYELINATED FIBERS IN FERRET INFERIOR ALVEOLAR NERVE NEUROMAS

Ectopic neural activity from damaged axons is thought to contribute to the development of sensory disorders following nerve injury. Here we have studied the role of sympathetic fibres in the generation or poten tiation of this abnormal activity by determining the effect of predege nerating these fibres. Twelve adult ferrets were used in the study and six of them underwent sympathectomy by removal of the left superior c ervical ganglion. Electrophysiological recordings were made from myeli nated axons in fine filaments dissected from the inferior alveolar ner ve, 3 days after it had been ligated further distally, and the level o f spontaneous activity and mechanical sensitivity was determined. Ther e was no significant difference between the level or characteristics o f spontaneous activity, or the level of mechanical sensitivity, in the two groups of animals. We conclude that, in this animal model, the ab sence of sympathetic nerve fibres does not affect the development or c haracteristics of ectopic neural activity in the early period followin g nerve injury. (C) 1998 Elsevier Science Ireland Ltd.