Fig. 3.

Astrocyte morphology remote from CNS lesions and with different gradations of reactive astrogliosis. Brightfield immunohistochemistry for GFAP counterstained with haematoxylin (H) in human autopsy specimens, surveys with details (boxed areas). a Appearance of astrocytes in tissue remote from a lesion and presumed healthy. Note that the territories of astrocyte processes do not overlap and that many astrocytes do not express detectable levels of GFAP. b Moderately reactive astrogliosis in which most (if not all) astrocytes have up regulated expression of GFAP and exhibit cellular hypertrophy, but with preservation of individual astrocyte domains and without pronounced overlap of astrocyte processes. c Severe diffuse reactive astrogliosis with pronounced up regulation of GFAP expression, astrocyte hypertrophy, astrocyte proliferation and pronounced overlap of astrocyte processes resulting in disruption of individual astrocyte domains. Scale bars surveys = 25 μm, details = 10 μm