Fig. 3

Hypoxia increases the size and number of neurospheres derived from rat BMSCs in an epidermal growth factor (EGF)-dependent manner. Representative images of nestin-positive rat BMSC-derived neurospheres formed following normoxia (a, c) and hypoxic preconditioning (b, d) with EGF supplementation at 20 ng / ml. e Hypoxic preconditioning led to an increase in sphere numbers with EGF concentrations at 200, 20, and 0.2 ng/ml. f A significant increase in sphere size as compared to the corresponding normoxic control was observed with EGF supplementation at 200 and 0.2 ng/ml. Mean ± SD, n = 4; *p < 0.05, **p < 0.01