FIGURE 8.

ERK5 is required in prolactin-induced SVZ neurogenesis in vivo. A, schematic illustration of experimental design. Tamoxifen was orally administered to female control (ERK5^loxP/loxP) or ERK5 inducible and conditional knock-out (icKO) mice (Nestin-CreER^TM/ERK5^loxP/loxP) for 7 consecutive days. Two weeks after the last dose of tamoxifen treatment, mice were infused with either vehicle or prolactin for 7 days followed by BrdU injection to label proliferating cells. Animals were perfused 0.5 h after the last dose of BrdU for immunostaining. B–E, representative immunostaining of adult mouse brain sections showing that tamoxifen treatment effectively knocks down ERK5 expression (green) in the SVZ of ERK5 icKO mice. Scale bar: 50 μm. F–I, confocal images of BrdU staining (red) in the SVZ of control mice (F, G) and ERK5 icKO (H, I) infused with vehicle (F, H) or prolactin (G, I). Scale bar: 50 μm. J, quantification of the total number of BrdU⁺ cells in the SVZ of control and ERK5 icKO mice. n = 4–5 mice/genotype/treatment. **, p < 0.01; n.s. not statistically significant.