Several characteristics of afferent flow following skin injuries

: Using a crosscorrelation method, the quantitative characteristics of afferent impulse flow in the n. saphenus were investigated under stimulation of cat's skin with acid, needles, and pins. The appearance of the nociceptive reaction served as a noxious stimulation test. Noxious mechanical and chemical stimuli affecting directly the nerve fibres activate the same afferent fibres as those activated by weak tactile ones exciting the receptors. The impulse flows under such conditions differ by the amount of active A and C fibres, their correlation and the activity duration in them. The nociceptive reaction is realized owing to a considerable predominance of activity in C fibres over that in A fibres and owing to the long activity duration in both kinds of fibres, particularly in C fibres. The paper demonstrates the possibility to use an optic correlometer for the analysis of the activity in a whole nerve.