3. Effects of capsaicin on nociceptive afferents from the skin

Capsaicin is a well-known excitant of cutaneous C-fibre nociceptors. In addition it has long-lasting effects on the functions of C-afferents in the rodent. Administration of capsaicin to neonatal rats causes a large reduction in the number of all functional classes of afferent C-fibre (Carpenter & Lynn 1983; Lynn 1984). We have now examined the effects of direct application to cutaneous nerves in adult animals and have found dramatic and selective effects on axonal conduction and nociceptor function.