Biochemical studies on frontal lobe white matter of young and old human brains

Frontal lobe white matter obtained at autopsy from 5 young (45–60 yr) and 5 non-demented old (77–78 yr) individuals was studied. Water, total protein, myelin basic protein (BP) content and 2′,3′-cyclic nucleotide 3′phosphohydrolase (CNP) activity in the frontal white matter of the two groups were compared. Myelin BP was measured by two different methods, RIA and batch extraction. Results indicated no significant changes in water and in total protein content. Myelin BP, as measured by both methods, however, was found to be significantly decreased in brains of the older group. CNP activity was also decreased but only slightly. This data suggests that with advancing age, myelin may undergo some qualitative changes.