Acid sensing ion channels 

Acid sensing (proton-gated) ion channels (ASICs) are low pH activated Na+ permeable ion channels that are members of a Na+ channel superfamily that includes the epithelial Na+ channel, the FMRF-amide activated channel of invertebrates, the degenerins of c. elegans, channels in drosophila and bile acid-activated ion channels known as BASICs.   ASICs are widely expressed in the central and peripheral nervous systems where they act as pH sensors and can detect a broad range of physiological changes as well as tissue acidosis at tissue injury, inflammation, ischemia, stroke, and tumour sites as well as at fatiguing muscle, which activates pain sensing nerves.  ASICs are involved in several physiological and pathological processes and their activation is involved in pain perception, synaptic plasticity, learning and memory, fear sensation, seizure termination, neurodegeneration after ischaemic stroke and mechanosensation.

Further reading

Kweon and Suh  (2013) Acid-sensing ion channels (ASICs): therapeutic targets for neurological diseases and their regulation. BMB Rep. 46(6) 295 PMID: 23790972

Cheng et al (2018) Acid sensing ion channels: dual function proteins for chemo-sensing and mechano-sensing. J Biomed Sci. 25(1) 46 PMID: 29793480

Vullo and Kellenberger (2020) A molecular view of the function and pharmacology of acid-sensing ion channels. Pharmacol Res. 154 104166 PMID: 30731197