Résumé
Reactive gliosis, leading to the formation of glial scar, is the response of astrocytes to CNS injury. It is an ubiquitous reaction observed in a large number of pathological conditions, such as mechanical and chemical lesions, as well as degenerative processes (Fulcrand and Privat, 1977; Eng and De Armond, 1982). This reaction is twofold, being characterized by an astrocyte multiplication (hyperplasia) as well as an hypertrophy of the perikarya and processes (Hain et al., 1960; Nathaniel and Nathaniel, 1981). The main intracellular event is an increase of the number of gliafilaments, paralleled by a raise in GFAP immunoreactivity.