Figure 3.

Impairment of neural migration, but not neurogenesis, in the SVZ and RMS. a, Representative images from the adult SVZ immunostained against BrdU after BrdU pulses 1 d earlier. Control and Tg1/Tg2 sections were counterstained with Nissl dye. b, Quantification of BrdU-positive cells in the SVZ/RMS region revealed no differences in the number of BrdU-positive cells in control and Tg1/Tg2 mice, either in the SVZ or in the RMS. c, Representative images from OB sections immunostained against BrdU, from control and Tg1/Tg2 mice BrdU injected 20 d before being killed. Note the reduced numbers of stained cells in the GCL. d, Densities of BrdU-labeled neurons in the GCL and PGC layers of the OB, demonstrating decreased numbers of BrdU-positive cells in the GCL of Tg1/Tg2 mice. e, Distribution of TH-immunoreactive cells in control and in Tg1/Tg2 OB tissue sections from 12-month-old mice. In controls, TH-positive cells are restricted to the PGC layer; in Tg1/Tg2 sections ectopic TH-positive neurons are detected in the GCL (arrows in right panel). The inset depicts ectopic TH-positive neurons. f, Density of ectopic TH-immunoreactive neurons in the GCL of control and Tg1/Tg2 mice at different ages; notice the marked increment at older ages. CC, Corpus callosum; DiV, days in vivo; PGC, periglomerular cell layer; LV, lateral ventricle; EPL, external plexiform layer; MCL, mitral cell layer; STR, striatum. Data are presented as mean ± SEM; ***p < 0.001; Student's t test. Scale bars: a, c, e, 100 μm.