Transient alterations in proliferation, ploidy, and gene regulation characterize subventricular differentiation. (A): Subventricular-derived NSCs proliferated in response to removal of mitogenic stimuli. (B): Twenty-four-hr incremental BrDU pulse labeling revealed increases in thymidine analog incorporation 24–72 hr following mitogenic differentiation in subventricular cultures. Alteration in gene expression accompanied differentiation in SVZ tissues: increases in cell cycle promoting genes 12–36 hr following mitogenic withdrawal (C) were followed by increases in cell cycle checkpoint genes (D). Mitogenic deprivation signaled increases in cellular growth (E) and aneuploidic (hyperploidic) cells (F), which were resolved upon the generation of neuroblasts. Abbreviations: BrDU, 5′-bromodeoxyuridine; diff, differentiated; hr, hour; nSVZ, non-subventricular zone; SVZ, subventricular zone.