Major population of MZ interneurons are wandering cells. Data are from DsRed cells in E12Ge:E15.5 GAD67-GFP cortices (n = 1; a in the abscissa of A and B) and GFP cells in E12Ge:E15.5 wild-type cortices (n = 7; b–h in the abscissa of A and B) (A–C) or mCherry cells in E15Ge:P1 GAD67-GFP cortices (D–F). A, D, The rate of migration of individual cells in E12Ge:E15.5 (n = 267 cells, 8 brains) (A) and E15Ge:P1 (n = 116 cells, 7 brains) (D) cortices. The dark gray bar indicates the range of cells categorized as stationary cells. B, E, The deflection angle of individual migrating cells from their preferred directions in E12Ge:E15.5 (n = 181 cells, 8 brains) (B) and E15Ge:P1 (n = 98 cells, 7 brains) (E) cortices. The white or light gray bar indicates the range of cells categorized as wandering or directed cells, respectively. C, F, The proportion of cells showing a stationary, directed, or wandering behavior in E12Ge:E15.5 (n = 267 cells, 8 brains) (C) and E15Ge:P1 (n = 116 cells, 7 brains) (F) cortices (average ± SEM).