Deep innervation of sural nerve

Discharges of 37 sural afferents in the A alpha to C fiber range have been recorded during stimulation of subcutaneous tissues after removal of the skin. Except for one A alpha unit with muscle spindle properties, fibers were not easily excited by muscle stretching. The more slowly conducting fibers tended to have higher thresholds. After repeated stimulation, most A delta and C units displayed a persistent afterdischarge which lasted from several minutes to more than half an hour.