Glial fibrillary acidic protein in astrocytes in the human neocortex.

Glial fibrillary acidic protein (GFAP), expressed in the brain by astrocytes, is one of the major immunocytochemical markers of these cells. The aim of the present work was to study the structure of GFAP-positive astrocytes in the human neocortex. Immunocytochemical confocal laser microscopy was used to characterize the main types of GFAP-immunoreactive astrocytes in the human neocortex. These were astrocytes of layer I, forming the superficial glial delimiting membrane, along with transmembrane astrocytes of layer I, with very long processes penetrating several layers of the cortex, astrocytes of the middle layers of the neocortex, mostly of the protoplasmic type and involved in forming perivascular delimiting membranes, and typical white matter fibrous astrocytes. These data may help unify assessments of histopathological processes seen in various types of gliosis in the CNS.