CORTICAL NMDA RECEPTOR PROPERTIES AND MEMBRANE FLUIDITY ARE ALTERED IN ALZHEIMERS-DISEASE

NMDA receptor density as measured by the specific binding of [H-3]MK 8 01 was significantly decreased (about 20%) in the frontal but not in t he parietal cortex of postmortem brain samples of Alzheimer's disease (AD) patients (n = 21), when compared with control brains (n = 20). Me mbrane fluidity was not altered in the frontal cortex samples, but was slightly reduced in the parietal cortex samples of the AD patients. S ince AD-specific histopathological changes (densities of senile plaque s and neurofibrillary tangles) were about similar in both areas, it is concluded that the reductions of NMDA receptor densities in the front al cortex is independent of AD-specific histopathological changes and of changes of membrane fluidity.