Glycine receptors are ligand-gated chloride channels. Channel opening is triggered by extracellular glycine. Channel opening is also triggered by taurine and beta-alanine (PubMed:2176511). Plays a role in the down-regulation of neuronal excitability. Contributes to the generation of inhibitory postsynaptic currents. Plays a role in cellular responses to ethanol. Inhibited by strychnine. Homopentamer (in vitro). Interacts with GLRB. Heteropentamer composed of GLRA2 and GLRB. Both homopentamers and heteropentamers form functional ion channels, but their characteristics are subtly different. The alpha-2* subunit isoform is present in neonatal rats, but not in older animals (PubMed:2176511, PubMed:1707830). Isoform Alpha-2* and isoform Alpha-2B are detected in embryonic and neonatal brain. At later postnatal stages, isoform Alpha-2* levels greatly decrease while isoform Alpha-2B is barely detectable (PubMed:1645300). The alpha subunit binds strychnine. Identical to the human subunit alpha-2, except for 5 substitutions at positions 18, 24, 37, 194 and 404. Substitution at position 194 (G -> E) accounts for the lower strychnine sensitivity observed in neonatal rats. Belongs to the ligand-gated ion channel (TC 1.A.9) family. Glycine receptor (TC 1.A.9.3) subfamily. GLRA2 sub-subfamily.