The formation of the myelin sheath, known as myelination, involves the wrapping of glial cells around the axon. In the central nervous system (CNS), oligodendrocytes are responsible for myelination, whereas in the peripheral nervous system (PNS), Schwann cells undertake this role. Each oligodendrocyte can myelinate multiple axons, whereas each Schwann cell myelinates a single axon segment.
