Knockdown of p116^Rip impairs neuroblast migration along the RMS. (A) Composite confocal images of forebrains of mice electroporated at P3 with plasmids expressing EGFP and scr#2 shRNA, p116^Rip#1 shRNA, or p116^Rip#1 shRNA together with RNAi-resistant p116^Rip and sacrificed at P10, showing distribution of EGFP⁺ transfected neuroblasts along the V-SVZ–RMS–OB pathway. Slices were counterstained with DAPI. Dotted lines outline borders of sagittal slices. Bar, 500 µm. (B) Quantification of the distribution of EGFP⁺ transfected cells along the V-SVZ–RMS–OB pathway. n = 816–2,100 cells from at least three animals for each condition. (C) Quantification of the length of the LP of neuroblasts expressing indicated constructs. n = 60–147 cells from at least three animals for each condition. (D–G) P2–3 mouse pups were electroporated with a tdTomato-expressing plasmid together with one of the indicated constructs. Acute sagittal brain slices were prepared 5 d later and subjected to confocal live-cell imaging. Quantification of the mean migrated distance (D), displacement (E), velocity (F), and number of branching events per h (G) for the tdTomato⁺ transfected neuroblasts. n = 40–52 cells from five to six animals for each condition. Data are shown as means ± SEM. **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; ns, P > 0.05 (B and C, compared with scr#2); one-way ANOVA with Dunnett’s post hoc test (B and C) or Student’s t test (D–G).