Figure 12

Co-analysis of BrdU incorporation with antigen expression indicates that division of both DCX⁺ neuronal progenitors and Olig2⁺ oligodendrocyte precursors is reduced by systemic exposure to cytarabine. In the CC, where there was an approximately 50% reduction in the number of BrdU⁺ cells (see Figure 11b), the proportion of BrdU⁺ cells that were Olig2⁺ was no different between controls and treated animals on either day 1 ((a) control; (b) cytarabine) or on day 56 ((c) control; (d) cytarabine) after completion of treatment. Thus, the reduction in apparent division of Olig2⁺ cells was proportionate to the overall reduction in all BrdU⁺ cells. In contrast with effects on Olig2⁺ populations in the corpus callosum, our analyses indicate an enhanced loss of DCX⁺ cells from among the BrdU⁺ population in both the SVZ and DG. This was particularly striking in the DG, where at 56 days post-treatment the proportion of BrdU⁺ cells in the cytarabine-treated animals was < 40% of that seen in control animals. Data are means ± SEM; *P < 0.05, **P < 0.01, and ***P < 0.001 in comparisons with control animals.