THE CONTRIBUTION OF CAPSAICIN-SENSITIVE AFFERENTS TO THE DORSAL-ROOT GANGLION SPROUTING OF SYMPATHETIC AXONS AFTER PERIPHERAL-NERVE INJURY IN THE RAT

Transection of the sciatic nerve leads to sprouting of sympathetic eff erent, noradrenergic axons and terminals around large cell bodies in t he dorsal root ganglion. Here we examined whether injury to unmyelinat ed afferents contributes to the sprouting. Neonatal treatment with the C-fiber neurotoxin capsaicin increased sprouting after nerve injury. We conclude that injury to large, rather than small diameter fibers, t riggers the sprouting of sympathetic efferents after nerve injury. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.