Glycine modulation of the phencyclidine binding site in mammalian brain

Neurophysiological studies have shown that glycine potentiates the NMDA response in cultured neurons by a strychnine-insensitive mechanism. Autoradiographic data have demonstrated a correspondence between strychnine-insensitive [ 3H]glycine binding sites and NMDA-sensitive [ 3H]glutamate binding sites. Here we report that in synaptic plasma membranes from rat brain, the binding of a PCP analog, [ 3H]TCP, was enhanced more than 5-fold by 1 μM glycine. This glycine stimulation of binding of [ 3H]TCP was blocked by the competitive NMDA-receptor antagonist, D-AP7. These data provide support for the hypothesis that a unique amino acid recognition site is associated with the proposed NMDA/PCP receptor complex in brain.