Mechanism of sympathetic efferent control of c-receptor responses to skin cooling in cats

The effect of sympathetic efferents on the afferent flow in C fibers was studied in acute experiments on cats. The number of C fibers active during skin cooling was found to be increased 5–7 sec but reduced 30–40 sec after stimulation of the sympathetic chain. The increase in activity in C-afferents can be explained by a change in the mechanical state of the skin during contraction of its contractile elements. The decrease in activity in C afferents, on the other hand, is evidently due to the effect of sympathetic nervous system mediators on C receptors or directly on afferent C fibers.