What are macrophages found in the brain called?

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

Answer: (B)

Microglia are the brain's resident macrophages. They originate from yolk sac myeloid precursors that migrate into the CNS early in development and remain as the primary immune effector cells within the brain. In a healthy brain they continuously survey the neural environment with branched processes, and when injury or infection occurs they become activated to phagocytose debris and pathogens, while releasing cytokines to coordinate the inflammatory response. Other glial cells have different roles: astrocytes support neuronal function, help maintain the blood–brain barrier, and regulate ion and neurotransmitter balance; oligodendrocytes form the myelin sheaths around CNS axons; ependymal cells line the ventricles and assist with cerebrospinal fluid production and movement. So, the macrophage-like cells in the brain are microglia.