Cation channel with high affinity for sodium, which is gated by extracellular protons and inhibited by the diuretic amiloride. Homotrimer or heterotrimer with other ASIC proteins. Expressed in central nervous system. First expressed at 48 hours post-fertilization (hpf). Expressed in dorsal midbrain and in retinal ganglion cells. Belongs to the amiloride-sensitive sodium channel (TC 1.A.6) family. ASIC4 subfamily.