GFAP and Alzheimer disease: Interestingly, in the visual cortex of AD brains with severe pathology, GFAP-immunoreactive astrocytes and plaques are arranged in a specific laminar distribution: indeed gliosis is preferentially localized in laminae II, III, IVa and IVc, the latter presenting a discrete plaque-associated glyotic horizontal band at the lower edge (Beach and McGeer, 1988).