Figure 1. Dual SMAD inhibition allows for a highly efficient neural induction of neuron and neural crest (NC) cells from hiPS cells.

(A) Differentiation scheme used for neural induction can be achieved with the combination of Noggin, a BMP inhibitor and SB431542, an ALK inhibitor; (B) By day 10, the cells appear dramatically thicker with densely packed nuclei and phase-bright ridges; (C) By day 20 the typical cell morphology of neuron under light field (LF); (D–I) By day 20, the neuron-like cells showed positive for mature neuron marker MAP2 (red) and Tuj1 (red) by immunocytochemistry; (J–R) By day 10, the hiPS cells could be selectively directed toward neural crest cells if neural induction began at lower densities. In this case more cells are observed expressing NC markers, p75 (red), HNK-1 (red) and AP-2α (red), but without expressing Pax6 (green), an early marker of neurectodermal differentiation. Nuclei were stained with DAPI (blue). Bars = 200 mm (B,D–F, J–R), 400 mm (C,G–I).