Which cell type forms myelin sheath in the CNS?

Which cell type forms myelin sheath in the CNS?

• A. Microglia
• B. Oligodendrocytes
• C. Astrocytes
• D. Schwann cells

Answer: (B)

In the central nervous system, the myelin sheath is formed by oligodendrocytes. These glial cells extend their processes to wrap around multiple axons, laying down multiple layers of membrane to create insulated segments that speed up electrical signaling through saltatory conduction. In contrast, Schwann cells form myelin in the peripheral nervous system, each wrapping around a single axon segment. Microglia are the CNS’s immune cells, and astrocytes support neurons and regulate the brain’s environment. Therefore, the cell responsible for CNS myelination is oligodendrocytes.

In the central nervous system, the myelin sheath is formed by oligodendrocytes. These glial cells extend their processes to wrap around multiple axons, laying down multiple layers of membrane to create insulated segments that speed up electrical signaling through saltatory conduction. In contrast, Schwann cells form myelin in the peripheral nervous system, each wrapping around a single axon segment. Microglia are the CNS’s immune cells, and astrocytes support neurons and regulate the brain’s environment. Therefore, the cell responsible for CNS myelination is oligodendrocytes.