Expression of nestin after traumatic brain injury in rat brain.

We tested the hypothesis that traumatic brain injury upregulates expression of nestin, an embryonic cell intermediate filament protein. Brain from rats (n=24) subjected to controlled cortical impact injury and sham operated (n=3) and normal (n=3) rats were processed for dual label immunohistochemical study to identify cellular expression of nestin. Our results show that in normal noninjured animals, nestin is expressed slightly and localized only in a few endothelial and subventricular cells. In contrast, at 1-4 weeks postinjury nestin is strongly expressed in astrocytes and microglia. The expression of nestin in astrocytes and microglia after traumatic brain injury support the hypothesis that injured cerebral tissue expresses developmental proteins, and that these proteins may promote recovery after injury.