Time-lapse series of two distinct patterns of hESC-derived neural differentiation on PDL/Laminin substrates. Phase contrast images of cell expansion at 0 hr, 3 hr, 1 day and 3 days postplating. Some hES cell-derived embryoid bodies (EBs) at 15 days of differentiation show a solid, dark core (dark EBs) (A at 0 hr postplating) while many EBs at 17–20 days of differentiation exhibit light, transparent appearance (light EBs) (B at 0 hr postplating). (A) From a dark EB, new cells constantly generate and radially migrate away from the center of the EB and form a rim of cells. These expanded cells are mixed neural progenitors and neurons (see Fig. 2). (B) light EB gives rise to a homogenous cell population composed of almost all neural progenitors (See Fig. 3). Scale bars: in (A) = 200 μm; in (B) = 100 μm.