Regulation of nestin expression after cortical ablation in adult rat brain

During embryogenesis, transient expression of nestin in proliferating neuroepithelial stem cells signals the commitment of progenitor cells to differentiate. Although adult mammalian brain contains very little nestin, significant upregulation of nestin has been reported following cerebral injury, leading to speculation that nestin may be involved in brain repair. In this study, we assessed the temporal profile of nestin expression following ablation injury of the sensory barrel cortex and investigated the influence of contralateral whisker stimulation on nestin expression. Since the adult mammalian brain contains proliferating neuronal progenitor cells that can be labeled with bromodeoxyuridine (BrdU), we also determined the association of nestin reexpression with BrdU-labeled cells. Nestin reexpression was detected predominantly in the ipsilateral cortex 3 days post-ablation. There was no significant nestin upregulation in the subcortical region. Nestin reexpression was most marked surrounding the lesion, but also extended throughout the entire lateral cortex. Nestin in the ipsilateral cortex subsided by day 7, although perilesional nestin expression was still apparent 28 days post-injury. Western blot analysis of nestin expression 3 days post-ablation confirmed a significant two-fold increase in nestin expression ( p