Fig. 4. Cell proliferation in adherent neurospheres. Neurospheres were allowed to adhere for 7 days and then incubated for 24 hours in the presence of 10 µM BrdU. Cells were fixed and processed for double-labeling with anti-BrdU (green) and anti-GFAP (red) antibodies. Note that most BrdU-positive cells were concentrated within the sphere, whereas only a few of them were found in the outgrowth. Bar, 100 µm.