Detailed quantification was performed for DCX-IR cells. DCX is a marker for young neurons, and the developmental stages of young neurons can be further delineated using morphological analysis. Early-phase DCX-IR cells represent a mixed population of proliferating late progenitors, transiently amplifying neuroblasts, and post-mitotic migrating cells that become immature neurons (Mandyam et al., 2008b). The late-phase DCX-IR cells, however, represent differentiating mature cells that co-label with mature neuronal markers such as NeuN (Kuhn et al., 2005; Mandyam et al., 2008b). Specifically early phase (immature) DCX-IR cells can be differentiated from the late phase (mature) DCX-IR cell types, with early phase cells having short processes and late phase cells having long processes that extend into the molecular layer of the dentate gyrus (Brown et al., 2003a; Brown et al., 2003b; Couillard-Despres et al., 2005; Mandyam et al., 2008a; Plumpe et al., 2006; Rao and Shetty, 2004; Serio et al., 1996). The early phase and late phase DCX-IR cells were quantified separately.
