Which glial cell is primarily involved in immune defense within the CNS?

Which glial cell is primarily involved in immune defense within the CNS?

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

Answer: (B)

Microglia are the brain’s resident immune cells. They constantly survey the CNS for pathogens and debris, and when they detect trouble they become activated, phagocytose invaders or debris, and release signaling molecules to recruit and coordinate other immune responses. This immune work is what sets them apart as the primary defense within the CNS. Astrocytes mainly provide support, maintain the blood-brain barrier, and regulate neurotransmission; oligodendrocytes myelinate CNS axons, and Schwann cells do the same for the peripheral nervous system. So the glial cell best known for CNS immune defense is microglia.

Microglia are the brain’s resident immune cells. They constantly survey the CNS for pathogens and debris, and when they detect trouble they become activated, phagocytose invaders or debris, and release signaling molecules to recruit and coordinate other immune responses. This immune work is what sets them apart as the primary defense within the CNS. Astrocytes mainly provide support, maintain the blood-brain barrier, and regulate neurotransmission; oligodendrocytes myelinate CNS axons, and Schwann cells do the same for the peripheral nervous system. So the glial cell best known for CNS immune defense is microglia.