Thickness of the VZ/SVZ (A), IZ (B), SP/CP (C), and pallium (D) in Ts16 (filled circles) and euploid (open squares) cortices. Data represent mean ± SEM (n = 6). Error bars are shown when larger than dimensions of symbols. In all areas examined, there were no differences at E13 (the IZ was not present in Ts16 or euploid brains at E13). However, abnormalities in thickness of the SP/CP, pallium, and IZ were apparent at E14 and were marked by E16. The Ts16 VZ/SVZ exhibited a slight increase at E14. By E18, all cortical layers were of normal thickness. *p < 0.05, **p < 0.001.