Effect of VPA on morphology and proliferation of NPCs. NPCs were treated with 1 mM VPA for 48 h in the presence or absence of 10 ng/ml bFGF. (A) Micrographs were taken at a magnification of 200×. (B) Cells were harvested and then counted using a hemocytometer. In three independent experiments, cells within the 230-μm square were counted and expressed as percent of the total number of cells in bFGF-treated cultures. Data represent mean ± SD of three separate experiments. P*** < 0.001 by one-way ANOVA followed by Newman-Keuls test.