Examination of beta-protein deposits in Alzheimer's cerebral cortices by three-dimensional observation.

We examined the location of beta-protein deposits (small diffuse plaques) in the cerebral cortices of Alzheimer's patients and aged nondemented controls by observing the methenamine silver stained serial sections. Some vessels, astrocytes or neuronal elements existed near or within the diffuse plaques, and the preamyloids in the plaques were frequently detected in direct contact with vessels, astrocytes or neuronal elements. Although these findings do not demonstrate that the beta-protein within the senile plaques is produced in various cellular elements of the brain, they suggest some associations between beta-protein deposition and vessels, astrocytes or neuronal elements.