[Effect of preliminary mechanical and antidromal influences on orthodromal activity in in group C fibers of cat skin mechanoreceptors].

The afferent activity in unmyelinated fibres of the cat's cutaneous nerve was analyzed using the colliding impulses method. The effect of antidromic activity induced by electrical stimulation of the nerve and of mechanical stimulation of the receptors on the subsequent orthodromic activity under stretching of the skin was investigated. Antidromic activity in the nerve as well as mechanical stimulation of the receptors decreased the subsequent orthodromic activity in response to testing stimulation. The maximum decrease of the activity was observed 10-15 s after stimulation. The duration of the inhibitory effect was considerably greater after mechanical stimulation. A simultaneous action of mechanical stimulation and antidromic activation produced a greater decrease of the afferent activity and prolonged the period for its recovery. An increase in the frequency of antidromic excitation to 8 imp/s increased its inhibitory influence on the orthodromic activity of C-fibres.