Glycine is an important inhibitory transmitter in the brainstem and spinal cord. Glycine receptors are members of the ligand-gated ion channel family (LGICs) that mediate rapid chemical neurotransmission (Schofield et al., 2003). The binding of glycine to its receptor produces a large increase in chloride conductance, which causes membrane hyperpolarization. Glycine receptors are anchored at inhibitory chemical synapses by a cytoplasmic protein, gephyrin (Fischer et al., 2000). The glycine receptor has been used to great advantage in the identification of the binding sites for alcohol on the LGIC family of proteins (Beckstead et al., 2001; Mihic et al., 1997). These receptors have also been extremely useful in studies of synaptic clustering of receptors (Craig and Lichtman, 2001). The glycine receptor may also act in concert with an NMDAR subunit to form an excitatory receptor (Chatterton et al., 2002).
