Which type of glial cell is responsible for forming myelin in the central nervous system?

Oligodendrocytes are specialized glial cells in the central nervous system (CNS) that play a crucial role in producing myelin, a fatty substance that insulates nerve fibers. This myelin sheath is essential for the efficient transmission of electrical impulses along neurons, allowing for faster communication between different parts of the nervous system. Each oligodendrocyte can extend its processes to myelinate multiple axons, enhancing the overall speed of neural signals.

Astrocytes, while important in maintaining the blood-brain barrier and supporting metabolic functions of neurons, do not form myelin. Microglia serve as the immune cells of the CNS, involved in response to injury and disease, but they are not responsible for myelination. Ependymal cells line the ventricles of the brain and the central canal of the spinal cord, contributing to the production and circulation of cerebrospinal fluid, but they also do not participate in myelin formation. Therefore, the role of oligodendrocytes in myelination is key to maintaining a healthy and functioning nervous system.