VPA suppressed Bax expression both in vitro and in vivo. (A) Bax expression was measured by Western blot. VPA reduced Bax expression in cultured NPCs. (B) The reduction of Bax expression was confirmed by immunocytochemical staining. Left, NPCs were stained with Bax. Middle, NPCs were stained with COX4, a marker of mitochondria. Right, merged image of Bax and COX4 staining. (C) VPA was injected into pregnant rats at E12 and Bax level in embryonic brain was determined at E14 and E16. The level of Bax in brain was decreased at both time points. Scale bar represents 10 μm.