“Myelin is synthesized as a multilamellar membrane, but the mechanisms of membrane turnover are unknown. We found that myelin pieces were gradually released from aging myelin sheaths and were subsequently cleared by microglia.”
“Myelin fragmentation increased with age and led to the formation
of insoluble, lipofuscin-like lysosomal inclusions in microglia. Thus,
age-related myelin fragmentation is substantial, leading to lysosomal storage and contributing to microglial senescence and immune dysfunction in aging.”
S.Safaiyan, et al
Age-related myelin degradation burdens the clearance function of microglia during aging
Nature Neuroscience — Volume 19 #8 — August 2016 — page 99