Fig. 6.

Neural cell proliferation and survival defects in the β8^–/– subventricular zone. (A,B) Sagittal brain sections from P60 wild-type (A) and β8^–/– (B) mice that were killed after receiving intraperitoneal injections of BrdU, were immunofluorescently labeled with anti-BrdU antibody. Dashed white lines denote ventricle boundaries. (C) Brain sections from wild-type (n=6) and β8^–/– (n=11) mice were immunofluorescently labeled with anti-BrdU antibody and BrdU⁺ cells were quantified by analyzing serial sections. Note the significant reduction in the numbers of proliferating cells in the SVZ of β8^–/– mutant mice, *P<0.001 compared with wild-type samples. (D,E) Ultrastructural analyses of SVZ regions dissected from P90 wild-type (D) and β8^–/– (E) mice. Unlike the wild-type SVZ (D), which contains distinct units of a, b and c cells, the SVZ in β8^–/– mice has an abnormal cytoarchitecture with increased numbers of apoptotic cells (arrows in E). (F) Serial coronal sections through the SVZ of P60 wild-type (n=7) and β8^–/– (n=9) mice were immunofluorescently labeled to identify TUNEL⁺ cells and these cells were quantified. Note the higher numbers of apoptotic cells in the SVZ of β8^–/– mice. *P<0.001 compared with wild-type samples. V, ventricle; BrdU, bromodeoxyuridine; a, SVZ type a neuroblast; b, SVZ neural stem cell; c, SVZ transit amplifying cell.