Astrocytes

Astrocytes are cells of the central nervous system which act as both physical and physiological support for the neurones that are embedded between them. They are particularly abundant in the grey matter, where they are the most abundant glial cells ¹.

They are highly branched and contribute to the blood-brain barrier, the subpial glia limitans, as well as regulating extracellular fluid transport (known as the glymphatic pathway). They also are important in the metabolic exchange between neurones and capillaries, as well as responding to mechanical and biochemical insults to the brain (e.g. gliosis) ¹. 

Histology

Immunohistochemistry

Astrocytes are most easily identified by immunohistochemical staining for GFAP and S100 ¹.