Cerebral organoids from hESCs were developed using a combination of two protocols (Supplementary Fig. 1a, Supplementary Methods). At day 8 the organoids formed stable cortical rosettes (Fig. 1, a1, a2) with proliferative Ki67 positive cells in the inner layer and a mixture of doublecortin positive (DCX+) neuroblasts and immature βIII-tubulin positive neurons in the outer layers (Fig. 1, a3, a4).
