Robust induction of GABAergic neurons was also observed after further maturation of MGE cells (Fig. 6a,b and Table 4). These GABAergic neurons expressed Lhx6, indicating their MGE origin (Fig. 6c,d and Table 4). In addition, these GABAergic neurons co-expressed Sox6 (Fig. 6e and Table 4), which has been recently shown to be a very specific marker for human MGE-derived interneurons [8]. Some of these cells expressed Calbindin (Fig. 6f and Table 4), which was expressed in some of the migrating interneurons. Some of these cells expressed more mature interneuron markers Parvalbumin (PV; Fig. 6g – i and Table 4) and Somatostatin (SST; Fig. 6j – l and Table 4) at this time point, as would be predicted from their MGE origin. CGE cells generated neural populations enriched with VIP+ or Calretinin+ neurons (Fig. 7a – d and Table 4), whereas few SST+ or PV+ cells were observed (Fig. 7e,f and Table 4).
