Myelin lipids in aging human brain.

The studies were performed on autopsy material of 18 patients who died between the ages of 70-89 y, and of 5 patients who died between 23-44 ys of age. White matter of the frontal lobe and of oerebellum was submitted for histological and biochemical analysis. The neuropathological data provided a rationale for dividing the material into two subgroups: one including patients mainly with vascular changes in the brain, and the other consisting of patients with senile atrophy of the Alzheimer type. Chemical alterations noted both in frontal lobe and in cerebellum were an increase in lysophosphatidylcholine content and a marked decrease in myelin yield. Additionally, in cerebellum a decrease in sulphatide content was observed. The chemical results were almost identical in the two subgroups of patients, although they differ in neuropathological patterns of lesions. It is emphasized that the general decrease in myelin yield as well as some minor changes in myelin lipid pattern seem to be a sign of aging and are not connected with atrophy of the Alzheimer type.