Which glial cell type forms the blood-brain barrier and provides metabolic support to neurons?

Which glial cell type forms the blood-brain barrier and provides metabolic support to neurons?

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

Answer: (A)

Astrocytes perform the two key roles described: they form the blood-brain barrier via their perivascular endfeet that wrap around brain capillaries and help create the selective environment by influencing tight junctions and transporter expression. They also provide metabolic support to neurons by taking up glucose from blood and converting it to lactate to shuttle to neurons as an energy substrate; they store glycogen and help regulate extracellular ions and neurotransmitters, keeping neuronal signaling smooth and preventing excitotoxicity. In contrast, other glial types have different primary jobs: oligodendrocytes make myelin, microglia act as immune cells in the CNS, and ependymal cells line the ventricles and help produce or move CSF. So, the glial cell most fitting both roles is astrocytes.

Astrocytes perform the two key roles described: they form the blood-brain barrier via their perivascular endfeet that wrap around brain capillaries and help create the selective environment by influencing tight junctions and transporter expression. They also provide metabolic support to neurons by taking up glucose from blood and converting it to lactate to shuttle to neurons as an energy substrate; they store glycogen and help regulate extracellular ions and neurotransmitters, keeping neuronal signaling smooth and preventing excitotoxicity. In contrast, other glial types have different primary jobs: oligodendrocytes make myelin, microglia act as immune cells in the CNS, and ependymal cells line the ventricles and help produce or move CSF. So, the glial cell most fitting both roles is astrocytes.