[3H]MK-801 binding in Alzheimer's disease.

The density of [3H]MK-801 binding sites was studied in homogenates prepared from different cortical regions of postmortem brains of Alzheimer patients and age matched controls. Highest number of binding sites for this noncompetitive antagonist of the N-methyl-D-aspartate (NMDA) receptor was in temporal pole (Brodmann area A-38) in both groups. There were no consistent differences between patients and controls in either binding density or affinity constant in any of the areas studied. Involvement of glutamatergic neurotransmission in Alzheimer's disease does not seem to be at the level of the MK-801 recognition site on the NMDA receptor complex.