It can be activated by a range of simple amino acids including glycine, β-alanine and taurine, and can be selectively blocked by the high-affinity competitive antagonist strychnine (Rajendra et al., 1997). Strychnine-sensitive glycine receptors (GlyRs) are members of a family of Ligand-gated ion channels. Receptors of this family are arranged as five subunits surrounding a central pore with each subunit composed of four α helical transmembrane segments (Miyazawa et al. 2003). There are presently four known isoforms of the α-subunit (α_1-4) of GlyR that are essential to bind ligands, and a single β-subunit. The adult form of the GlyR is the heteromeric α₁β receptor, which is believed to have a stoichiometry of three α₁ subunits and two β subunits (Kuhse et al., 1993) or four α₁ subunits and one β subunit (Kuhse et al., 1995). The α-subunits are also able to form functional homo-pentameric receptors in heterologous expression systems in African clawed frog's oocytes or mammalian cell lines (Kuhse et al., 1995), and the α₁ homomeric receptor is essential for studies of channel pharmacokinetics and pharmacodynamics (Lewis et al., 2003).