We differentiated iPSC lines into telencephalic neurons using a modification of our free-floating tridimensional (3D) culture method (Mariani et al., 2012). Briefly, floating aggregates composed of manually isolated neural rosettes, which are early neural progenitors, were kept in suspension for one week under growth-promoting conditions and then for four to five weeks under conditions favoring terminal differentiation (see Extended Experimental Procedures and schematic outline in Figure S3A).
