The function of ENSG00000110881 (ASIC1, acid sensing ion channel subunit 1) is as follows. Forms voltage-independent, pH-gated trimeric sodium channels that act as postsynaptic excitatory receptors in the nervous system, playing a crucial role in regulating synaptic plasticity, learning, and memory (PubMed:21036899, PubMed:32915133, PubMed:34319232). Upon extracellular pH drop this channel elicits transient, fast activating, and completely desensitizing inward currents (PubMed:21036899). Displays high selectivity for sodium ions but can also permit the permeation of other cations (PubMed:21036899). Regulates more or less directly intracellular calcium concentration and CaMKII phosphorylation, and thereby the density of dendritic spines. Modulates neuronal activity in the circuits underlying innate fear (By similarity). {ECO:0000250|UniProtKB:Q6NXK8, ECO:0000269|PubMed:21036899, ECO:0000269|PubMed:32915133, ECO:0000269|PubMed:34319232}. [Isoform Asic1a]: Has high selectivity for sodium ions, but can also be permeable to other cations including calcium, lithium and potassium. . [Isoform Asic1b]: Produces acid activated currents with a reduced amplitude and inactivates faster (PubMed:21036899). Has high selectivity for sodium ions but also supports a calcium-mediated current which is sustained and maintained as long as acidic conditions are present (PubMed:21036899). Also potentially permeable to lithium and potassium (PubMed:21036899). . [Isoform 1]: Has no measurable proton-gated sodium channel activity in vitro. .