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 of the injury increase gene expression, thus compounding the response of other astrocytes and contributing to the heterogeneity. Particularly, astrocytes closest to the lesion generally secrete more inhibitory molecules into the extracellular matrix. Microglia are the second most prominent cell type present within the glial scar. They are the nervous system analog of immune system macrophages. Microglia rapidly activate near the injury and secrete several cytokines, bioactive lipids, coagulation factors, reactive oxygen intermediates, and neurotrophic factors. The expression of these molecules depends on the location of the microglial cells relative to the injury, with the cells closest to the injury