Glial scar hand, absence of the glial scar has been associated with impairments in the repair of the blood brain barrier. The glial scar is composed of several components briefly discussed below. Reactive astrocytes are the main cellular component of the glial scar. After injury, astrocytes undergo morphological changes, extend their processes, and increase synthesis of glial fibrillary acidic protein (GFAP). GFAP is an important intermediate filament protein that allows the astrocytes to begin synthesizing more cytoskeletal supportive structures and extend pseudopodia. Ultimately, the astrocytes form a dense web of their plasma membrane extensions that fills the empty space generated by the
Glial scar molecules that chemically prevent axonal extensions. Moreover, the basal membrane component is expected to generate an additional physical and chemical barrier to axonal extensions. The formation of the glial scar is a complex process. Several main classes of molecular mediators of gliosis have been identified and are briefly discussed below. Two neuronally-important subclasses of transforming growth factor family of molecules are TGFβ-1 and TGFβ-2 that directly stimulate astrocytes, endothelial cells, and macrophages. TGFβ-1 has been observed to increase immediately after injury to the central nervous system, whereas TGFβ-2 expression occurs more slowly near the injury site. Further, TGFβ-2 has been