Astrocytes
Astrocytes are specialized glial cells that contiguously tile the entire central nervous system (CNS) and exert many complex functions in the CNS. The intermediate filament glial fibrillary acidic protein (GFAP) is expressed by many of the astrocytes, which are traditionally identified using histological analysis. There are three types of astrocytes in the central nervous system: fibrous (in white matter), protoplasmic (in gray matter), and radial.