ASIC channels belong to the ENaC/Degenerin superfamily and are proton-gated ion channels which are not voltage-dependent. Six different genes encode the different ASIC subunits and splice variants: ASIC1a, ASIC1b, ASIC2a, ASIC2b, ASIC3 and ASIC4.

ASIC channels sense protons and interact with proteins (namely proteases) and other ions such as Zn²⁺ and Ca²⁺ through their extracellular domains. The extracellular loop of ASIC1a undergoes cleavage by extracellular trypsin (a serine protease) which is responsible for shifting the pH dependence of the channel activation and inactivation to more acidic pH¹.

These channels are expressed in the brain and in the nervous system² but have also been found in the retina, testes, and other tissues^3,4 where they are involved in many physiological processes including nociception⁵, learning and memory⁶, mechanosensation⁷ among others.