Figure 4. Timecourse of LacZ expression in Mtss1L reporter mice.

(A) Schematic representation of the experimental paradigm used for the Mtss1L reporter mice. KOMP Mtss1l ^+/- were either housed in their homecage or exposed to 2 hr of voluntary exercise. Brain sections were processed for LacZ immunohistochemistry at several time points. (B) Pink lines outline the granular cell layer of the dentate gyrus based on DAPI staining and blue square identifies the area magnified at right. LacZ was detected only in dentate granule cells of mice at 3 days post-exercise (bottom, right), whereas no expression was observed in homecage littermates (bottom, left). Scale bars: 250 µm, 12 µm. (C) LacZ expression in granule cells peaked at 3 days post-exercise and was not detectable at 5 or 7 days post-exercise (LacZ+ cells/mm³ 2 days post-exercise: 1235 ± 345, n = 3; 3 days post-exercise: 4573 ± 767,n = 3, one-way ANOVA p<0.0001).