Acid-sensing Ion Channels in Sensory Perception

Acid-activated currents blocked by amiloride have been reported for a long time in most neurons of the mammalian brain as well as in sensory neurons (1). A decade ago, Waldmann and colleagues (2) were the first to clone the ion channels underlying these currents, which have been called acid-sensing ion channels (ASICs).2 ASICs are neuronal voltage-insensitive cationic channels activated by extracellular protons. They belong to the ENaC/DEG (epithelial amiloride-sensitive Na+ channel and degenerin) family of ion channels (3).