Multivesicular bodies in cortical dendrites of two patients with Alzheimer's disease.

Biopsy fragments from the frontal cortex of 2 patients with Alzheimer's disease were studied with ultrastructural and cytochemical methods. A great number of light and dark, acid phosphatase positive, multivesicular bodies were observed in dendrites and their spines, in all cortical layers, being more abundant in layers 3 and 4. A close topographic relationship between these organelles and post-synaptic membranes was found. It is postulated that these findings might be related to the neurite formation of the senile plaques and to the synaptic involvement in Alzheimer's disease.