Hippocampal Neurogenesis images (total of 10–14 mm thick) from framed areas or pointing arrows in panels B2, D3 and E1. The white crosshairs in these panels were positioned to show co-expression in single cells of markers of interest, as labeled above each panel. Arrows and arrowheads point at cells of interest. CA = cornu ammonis, LV = lateral ventricle, SGZ = sub granular zone, GCL = granule cell layer, SVZ = subventricular zone, h = hilus. Scale bars: 300 mm (A), 50 mm (B1–3, C1–4, D1–3 and E1), 25 mm (B4, D4, D5 and E2–5). doi:10.1371/journal.pone.0004779.g008 Figure 9. Model of postnatal hippocampal granule neurogenesis. Multipotent GFAP/Nestin/Pax6/Glast+ radial glia stem cells give rise to multipotent and highly dividing Pax6/Mash1+ progenitors. Ngn2 initiates neuronal commitment of Pax6/Mash1+ progenitors. Ngn2 progenies undergo asymmetric divisions and amplify until they divide symmetrically and express NeuroD1. NeuroD1 stops the amplification phase of Ngn2 progenies and direct neuronal maturation. NeuroD1 progenies undergo maturation through the expression of the transcription factors Tbr1, NeuroD2 and Prox1 and the cellular markers Dcx, PSA-NCAM, Calretinin and NeuN. doi:10.1371/journal.pone.0004779.g009 PLoS ONE | www.plosone.org 14 March 2009 | Volume 4 | Issue 3 | e4779