(guinea pig, 1:1,000; Millipore: AB2253); anti–TBR1 (rabbit, 1:200; Abcam: AB31940), anti–GFAP (rabbit, 1:1,000; DAKO Z0334), anti–CTIP2 (rat, 1:300; Abcam: AB18465), anti–OCT4 (rabbit, 1:200, Cell Signaling Technology), anti–SSEA4 (mouse, 1:200, Cell Signaling Technology). AlexaFluo Dyes (Life Technologies) were used at 1:1000 dilution for amplifying the signal. Nuclei were visualized with Hoechst 33258 (Life Technologies). Cryosections were mounted for microscopy on glass slides using Aquamount (Thermo Scientific) and imaged on a Zeiss M1 Axioscope or Leica TCS SP8 confocal microscope. Images were processed in ImageJ (Fiji).
