Astrocytes and the Blood Brain Barrier

Astrocytes, like the one highlighted here by GFAP stain, are star-shaped glial cells that are involved in a large number of CNS functions, including the blood brain barrier. Together with pericytes and endothelial cells, astrocyte end plates surrounding a vessel forms an essential component of the blood brain barrier which severely limits passage of certain substances into the brain and thereby protects the brain from harmful effects of drugs or toxins in the blood.