Immunolocalization of Notch1, Hes1, and Nf-Kb in the Murine Hippocampal Subgranular Zone (SGZ): Possible Role of the Notch Pathway in the Maintenance of the SGZ Neural Stem Cell Population.

The subgranular zone (SGZ) of the hippocampal dentate gyrus harbors neural stem cells that provide continued adult neurogenesis. The signals from the microenvironment maintain the neural stem cell population in this region. Nonetheless, the identity of these signals is largely unknown. In our study, we analyzed the existence of activated Notch1 (NICD), Hes1, and NF-kB in the SGZ of the murine hippocampus to elucidate the involvement of the Notch pathway in the maintenance of neural stem cell population in this zone. We performed immunohistochemistry and immunoblotting for the above molecules on adult and postnatal developing murine hippocampal tissues. The immunoblot analysis showed a gradual increase in the expression of NICD, Hes1, and NF-kB, as the postnatal hippocampus develops. Immunohistochemical analysis showed a highly positive immunoreactive staining for NICD, Hes1, and NF-kB in cells of the SGZ. Altogether, our own data suggest that the Notch pathway is activated in the SGZ and can play an important role in the regulation of the neural stem cell population in the above. [ABSTRACT FROM AUTHOR]