Disrupted interneuron tangential migration in Disc1- L100P embryonic mice. (A) Coronal sections of either E14 or E16 embryonic brains immunostained with CB were straightened and divided into seven equidistant bins covering the tangential migratory pathway of interneurons. Fluorescently-labeled cell numbers were counted in each bin and normalized to the total number in all bins. The distribution of these interneurons was significantly different for both E14 and E16 time points between WT and Disc1-L100P (two-way ANOVA, p < 0.01). (B) E14 CB-immunolabeled images of WT and Disc1- L100P mice are shown on the left. Disc1- L100P mice had a significantly lower proportion of CB-cells in the ventral bin 6 when compared to WT controls (n = 25–28 sections from 4 different embryos per group, t-test, p < 0.05). (C) At E16, a more pronounced difference in interneuron tangential migration was observed between WT and Disc1- L100P mice (white arrows). Disc1- L100P mutants had significantly less CB+ cells in bins 3 and 4, while more remained near the ventral bin 6 when compared to WT (n = 19–24 sections from 4 different embryos per group, t-test, p < 0.01). Scale Bar, 300 μm. All data are shown as mean ± SEM; * p < 0.05, ** p < 0.01 versus WT. CB, calbindin.