The myelin sheath consists of multiple layers of cell membrane. These membranes are rich in lipids and proteins, such as myelin basic protein (MBP), proteolipid protein (PLP), and myelin-associated glycoprotein (MAG). The high lipid content, including cholesterol, cerebrosides, and sphingomyelin, gives myelin its characteristic white appearance in the white matter of the brain and spinal cord.
