The neural stem cell niche in the subventricular zone. (a) Localization of the canonical germinative zones in the brain, the subventricular zone (SVZ), and the subgranular zone (SGZ). (b) NSC proliferation in the SVZ is stimulated by autocrine bFGF signalling and inhibited by CBF1-dependent Notch signalling. Noggin, secreted by ependymal cells, may inhibit Bmp signalling via Bmp receptors on NSCs and intermediate neural progenitors (INPs). Endothelial cells provide for regulatory factors including VEGF that stimulate INP proliferation. INP proliferation is inhibited by Bmps and CBF1-independent Notch signalling.
