New method to identify nociceptor units innervating glabrous skin of the human hand.

A new technique is described for detecting nociceptor activity in microelectrode recordings from cutaneous fascicles of the human median nerve. The search strategy involves combined intraneural microstimulation and microneurographic recording in intrafascicular sites, where a critically low electrical stimulus amplitude evokes a threshold sensation of pain. From the subject's projection of pain to a small area of skin, the experimenter is guided to receptive fields of recordable nociceptor units. This technique has allowed, for the first time, to identify and study receptive properties of very high threshold nociceptors with A and C fibers in the glabrous skin of the human hand.