Increased BrdU incorporation and increased number of neural progenitor cells in response to LIF treatment. (A): Quantification of BrdU-positive, nestin-positive, and BrdU/nestin-double positive cells 48 h after plating. Error bars indicate S.E.M., * indicates p < 0.05, ** indicates p < 0.01, n = 8. Total cell numbers did not differ significantly when we compared LIF-treated with untreated cultures (1934 ± 403 and 2008 ± 435, respectively). (B-C): Representative pictures of plated sphere-derived cells without LIF treatment (B), and with 10 ng/ml LIF (C). Scale bar = 200 μm. (C'-C''): Higher magnification of two nestin-positive cells from (C) to illustrate the nuclear localization of the BrdU staining in one of the cells.