The function of CHRNA2 (cholinergic receptor nicotinic alpha 2 subunit, ENSG00000120903) is as follows. Component of neuronal acetylcholine receptors (nAChRs) that function as pentameric, ligand-gated cation channels with high calcium permeability among other activities. nAChRs are excitatory neurotrasnmitter receptors formed by a collection of nAChR subunits known to mediate synaptic transmission in the nervous system and the neuromuscular junction. Each nAchR subunit confers differential attributes to channel properties, including activation, deactivation and desensitization kinetics, pH sensitivity, cation permeability, and binding to allosteric modulators (PubMed:18723036). CHRNA2 forms heteropentameric neuronal acetylcholine receptors with CHRNB2 and CHRNB4 and plays a role in nicotine dependence (PubMed:24467848, PubMed:27493220). {ECO:0000269|PubMed:24467848, ECO:0000269|PubMed:27493220, ECO:0000303|PubMed:18723036}.