The dual role of the neurotransmitter Glycine in the CNS

Glycine, the simplest of all amino acids, inhibits postsynaptic neurons via strychnine-sensitive glycine receptors and, together with glutamate, enhances neuronal excitation by the activation of excitatory N-methyl-D-aspartate (NMDA) receptors. Studies at the MPI for Brain Research indicate that a distinct NMDA receptor subtype is activated by glycine alone, and thus functions as an “excitatory glycine receptor”. Recent results establish a central role of glycine in the regulation of neuronal excitability.