Anatomy:

• Star-shaped, with many long, branched processes.

• End-feet make contact with capillaries and neurons.

• Expresses GFAP (glial fibrillary acidic protein).

Function:

• Maintain blood-brain barrier via end-foot interactions with endothelial cells.

• Regulate extracellular ion concentrations (especially K+).

• Recycle neurotransmitters (e.g., glutamate → glutamine).

• Provide metabolic support—transfer glucose/lactate to neurons.

• Modulate synaptic activity—release gliotransmitters (e.g., ATP, D-serine).

• Involved in neuroinflammation and scar formation post-injury (reactive gliosis).