Figure 3.

Blocking SDF1 signaling in brain slices increases branching and shifts interneuron distribution toward the cortical plate (CP). A, Control-treated Dlx5/6-Cre-IRES-GFP animals express GFP in interneurons born in the medial and lateral ganglionic eminences. The brain slice in A shows typical stream migration in the marginal zone, MZ, and subventricular zone/intermediate zone, SVZ/IZ. B (and supplemental Figs. 3, 5, video 1), Blocking SDF signaling with AMD3100 results in a loss of distinct interneuron stream migration and an increase in interneurons in the cortical plate. C, Quantification of interneuron branching frequency shows a significant increase in branching in slices when SDF1 signaling is blocked. Error bars are ± SEM (***p < 0.001, t test); 18 cells for each condition; six independent experiments. D, Interneurons normally contained in the SVZ/IZ migration stream (bins 5 and 6) are shifted outwards toward the cortical plate (bins 7 and 8) in slices with blocked SDF1 signaling. Several interneurons also migrated toward the VZ (bin 1) in AMD3100-treated slices. Error bars are ± SEM (*p < 0.05, **p < 0.01, ***p < 0.001, χ² test); 10 slices for each condition; three independent experiments; cntl, Control. Scale bar, 100 μm.