Figure 3.

Depletion of neuroblasts with a concomitant increase in dividing Mash1⁺ cells in the OB of APC-CKO mice. A. Quantification of BrdU⁺ dividing cells (administered 2 h before tissue harvest), Mash1⁺ cells, and Dcx⁺ neuroblasts through the SVZ-RMS. Scheme illustrating coronal sections at different rostrocaudal levels used for quantification; the anterior SVZ(1), caudal RMS(2), rostral RMS(3), and OB-RMS(4). n=4-7, *p<0.05, **p<0.01, ***p<0.001 versus controls, t test. B, Representative images of coronal sections of the SVZ and OB stained by BrdU, Ki67, GFAP, Mash1, Dcx, and PSA-NCAM. Note that BrdU⁺ and Ki67⁺ dividing cells as well as Mash1⁺ cells markedly increase, whereas Dcx⁺ and PSA-NCAM⁺ neuroblasts are depleted in the OB of CKO mice. C. BrdU⁺ dividing cells in the OB of CKO mice are frequently positive for GFP and Mash1, and occasionally positive for Olig2 (arrowhead), but negative for Dcx, GFAP, and S100. Scale bars: B, 20 μm; C, 10 μm. SVZ, subventricular zone; RMS, rostral migratory stream; OB, olfactory bulb; GCL, granule cell layer, LV, lateral ventricle; Dcx, doublecortin.