Activity from skin mechanoreceptors recorded percutaneously in awake human subjects.

A technique is described which allows recording of multi-fiber discharge and single-unit activity from intact peripheral nerves of awake human subjects. A tungsten electrode with a tip diameter of 5-15 p was driven manually through skin, subcutaneous tissues and nerve sheath. From many recording sites in mixed nerve trunks neural impulses with an amplitude of 40 .uv were recorded in response to peripheral mechanical stimuli. It was possible to judge when afferent nerve fibers of cutaneous origin lay close to the electrode tip by the quality of the insertion paresthesias and the type of peripheral stimuli required to induce afferent responses. Examples are presented of fast and slowly adapting mass discharge induced by mechanical stimuli on glabrous and nonglabrous skin areas. When single-unit activity was discriminated it was often possible to determine the site of the cutaneous end organ, the discharge characteristics of the unit, and the conduction velocity of the nerve fiber. Ten such single-unit recordings are described.