Fig. 1.

Absolute (a) and relative (b) numbers of bromodeoxyuridine (BrdU)-positive cells and subpopulations at 1 day and 4 weeks after 10 BrdU injections. Most BrdU-positive cells were neuron-glia 2 (NG2)-immunoreactive and weakly co-expressed S100β (S100b). These cells appeared to proliferate slowly, and many of them still expressed NG2 at 4 weeks after BrdU. Microglia (expressing ionized calcium-binding adaptor molecule 1 [Iba-1]) and oligodendrocytes (expressing 2',3'-cyclic nucleotide 3'-phosphodiesterase [CNPase]) constituted smaller fractions of the total BrdU-positive cells (error bars SEM)