Validation of striatal neurons. (A): Colocalization of MAP2 with calbindin and with GABA. (B): Colocalization of MAP2 and DARPP-32 at the beginning and the end of the differentiation protocols. (C): Colocalization of DARPP-32 and CTIP2. (D): Quantitative reverse transcriptase-polymerase chain reaction analysis of different MSN markers. Levels of statistical significance were set at ∗, p < .05, ∗∗, p < .01, and ∗∗∗, p < .001. The scale bars correspond to 50 μm on the specimen level. Abbreviations: D, day; DAPI, 4′,6-diamidino-2-phenylindole; NPC, neural progenitor cell; P1, two-step protocol; P2, three-step protocol.