Basic electrophysiology in nociception

Abstract

Sensory receptors that respond to noxious stimuli, called nociceptors, in the skin are present in free nerve endings of Aδ- and C-fibers. The Aδ-nociceptors develop picking pain and fast pain in response to mechanical stimulation. On the other hand, the C-nociceptors develop burning pain and slow pain in response to thermal, cold, chemical, and mechanical stimulation. In these free nerve endings, mechanical stimuli activate ion channels, such as piezo1 or ASICs, thermal stimuli activate ion channels, such as TRPV1, TRPV2, TRPV3, or TRPV4, cold stimuli activate ion channels, such as TRPM8 or TRPA1, and chemical stimuli activate ion channels and receptors, ASCIs, TRPV1, TRPV3, TRPM8, TRPA1, ATP receptors, or B2 receptors. In this review, we summarize the roles of ion channels and receptors in the nociception from the electrophysiological point of view.