The brain’s white matter comprises areas of the central nervous system made up of myelinated axons. Its name is derived from the pale appearance of the lipids that comprise myelin. Myelin is a segmented sheath that insulates axons, ensuring the conduction of neural signals. The loss of myelin is documented in a number of neurodegenerative pathologies, including Alzheimer’s and Parkinson’s disease, and perhaps most notably, multiple sclerosis. As people age, demyelination becomes more likely.