Glycine receptors are ligand-gated chloride channels . Channel opening is triggered by extracellular glycine . Channel opening is also triggered by taurine and beta-alanine . Channel characteristics depend on the subunit composition; heteropentameric channels are activated by lower glycine levels and display faster desensitization . Plays an important role in the down-regulation of neuronal excitability . Contributes to the generation of inhibitory postsynaptic currents . Channel activity is potentiated by ethanol . Potentiation of channel activity by intoxicating levels of ethanol contribute to the sedative effects of ethanol (By similarity).