Decreased myelin basic protein content of the aged human brain

Abstract

Myelin basic protein was extracted from frontal lobe white matter obtained at autopsy from seven individuals ranging in age from 72 to 78 years. Qualitative and quantitative comparisons were made between basic protein from this group and that extracted from another group of individuals ranging in age from 45 to 65 years. The basic protein content of the older brains was considerably lower than that of the younger brains. Qualitative studies that included assay for encephalitogenic activity, disk gel electrophoresis at pH 4.3, and immunoprecipitation did not reveal any difference in the basic protein derived from the two age groups. Possible factors that may help explain the decreased basic protein content of the aged brain are discussed.