Linkage between phencyclidine (PCP) and N-methyl-D-aspartate (NMDA) receptors in the cerebellum.

It has been suggested that phencyclidine (PCP) receptors may not be linked with N-methyl-D-aspartate (NMDA) receptors in all brain areas. We found that NMDA enhanced [3H]TCP (a PCP analog) binding in extensively washed cortical, but not cerebellar membranes. However, PCP potently inhibited NMDA-induced [3H]norepinephrine release from cerebellar slices in a concentration-dependent manner, suggesting that a subtype of cerebellar PCP receptors is functionally linked with NMDA receptors. It is suggested that this subtype cannot be demonstrated by [3H]TCP binding because of the predominance of low affinity PCP receptors in the cerebellum.