Myelin in the CNS and PNS.

Myelin in the Central Nervous System (CNS) vs. Peripheral Nervous System (PNS)

Myelin is a protein-rich lipid sheath that coats and electrically insulates neuronal axons to facilitate rapid transmission of action potentials.

• Myelin in the CNS: Produced and maintained by oligodendrocytes. A single oligodendrocyte can myelinate up to 50 different axonal segments from multiple neurons. The major proteins are Proteolipid Protein (PLP) and Myelin Basic Protein (MBP).
• Myelin in the PNS: Produced by the Schwann cells. Each Schwann cell wraps around a single segment of a single peripheral axon. The key structural protein is Myelin Glycoprotein Zero (P0).