Afferent Cutaneous C-fibre Reactivity to Repeated Thermal Stimuli

Abstract

SINGLE afferent C-fibres from the skin of the rat's tail were isolated by the method described by Hensel, Iggo and Witt¹. These fibres were non-specific; activity was recorded in them both to mechanical and strong thermal stimuli applied to the skin. There was in this respect a strong similarity between these fibres and a few C-fibres in the cat's skin described by Iruichijima and Zotterman² which responded to mechanical stimuli, to heating the skin above 50° C. and to cooling the skin below 10° C. Non-specific fibres responding to all kinds of noxious and non-noxious thermal and mechanical stimuli have been found recently by Witt³ and fibres, responding to extreme thermal stimuli only by Iggo⁴. It has been suggested^2–4 that these fibres might have a “nociceptive function”. The present investigations, which concern the behaviour of non-specific C-fibres to repeated stimulation, would appear to confirm the suggested “nociceptive function” of these afferents.