Comparison of Lhx9(left) and Lhx2 (right) expression in the neocortical epithelium at indicated stages. The pial surface (p) is at the top, and the ventricular surface (v) is at thebottom. Left and rightphotographs were taken on adjacent sections. cp, Cortical plate; iz, intermediate zone;mz, marginal zone; pp, preplate;sp, subplate; svz, subventricular zone;vz, ventricular zone. Scale bars, 100 μm.