Radial organization and immunocytochemical patterns at the end of DS1. A. Ectopic expression of pShhiEGFP in an electroporated OT (ED4.5); patches of positive NE cell bodies at the ventricular zone (VZ) and of postmitotic neurons at the premigratory zone (PMZ) can be observed. B. Hematoxylin-Eosin staining. Arrowheads point to mNE cells located along ventricular zone; they show PH3 nuclear labeling (C) and Notch reactive cytoplasm (D). Arrows point to neurons in the premigratory zone; they display nuclear NeuroD reactivity (E) and βIIITub reactive perikarya (F). Bar: 10 μm.