Immunostaining of brain sections or dissociated neural cells was performed as described previously (Kim et al. 2004 (link); Ka et al. 2016b (link)). The following primary antibodies were used: Mouse anti-NeuN (EMD Millipore, MAB337), rat anti-neural cell adhesion molecule L1 (EMD Millipore, MAB5272), rabbit anti-TBR1 (Abcam, ab31940), rabbit anti-CUX1 (Santa Cruz, sc-13024), chicken anti-MAP2 (Abcam, ab5392), rabbit anti-GFAP (Abcam, ab7260), rabbit anti-Ki67 (Cell Signaling, #9129), rabbit anti-phospho-Histone H3 (Cell Signaling, #9701S), mouse anti-BrdU (BD Biosciences, 555627), chicken anti-Tbr2 (EMD Millipore, ab15894), rabbit anti-BLBP (Abcam, ab32423), mouse anti-Nestin (PhosphoSolutions, 1435-NES), rabbit anti-ARL13B (Abcam, ab83879), rabbit anti-Acetyl-α-Tubulin (Cell Signaling, #5335), chicken anti-GFP (Thermo Fisher, A10262), rabbit anti-GFP (Thermo Fisher, A11122) and mouse anti-MACF1 (Santa Cruz, sc-377532). Alexa Fluor568-Phalloidin (Thermo Fisher, A12380) was used to stain polymerized actin. Appropriate secondary antibodies conjugated with Alexa Fluor dyes (Thermo Fisher) were used to detect primary antibodies. The purpose of using each antibody is listed in Table1.