E, F, Luciferase assay in rTg4510:Fluc-EGFP mice. E, Left, scheme of brain regions used for luciferase assay color-coded by their vulnerability to tau pathology. Right, specific luciferase activity measured in the indicated brain regions of 4-month-old and 16-month-old rTg4510:Fluc-EGFP mice normalized to control littermates. F, Fluc-EGFP protein quantity in the indicated brain regions of rTg4510:Fluc-EGFP mice measured by Western blot (for representative blots, see Fig. EV3B). Values are normalized to control littermates. N=6 rTg4510:Fluc-EGFP mice, 4 WT:Fluc-EGFP mice, 6 CaMKIIα-tTA:Fluc-EGFP mice and 1 tetO-tauP301L:Fluc-EGFP mouse at 4 months; 4-5 rTg4510:Fluc-EGFP mice, 5 WT:Fluc-EGFP mice, 3 CaMKIIα-tTA:Fluc-EGFP mice and 4 tetO-tauP301L:Fluc-EGFP mice at 16 months. WT:Fluc-EGFP, CaMKIIα-tTA:Fluc-EGFP and tetO-tauP301L:Fluc-EGFP littermates did not differ from each other and were pooled together as controls. Light-red and dark-red asterisks indicate comparisons to the corresponding littermate group (one-sample t-test), black asterisks indicate significant comparisons between corresponding brain regions of rTg4510:Fluc-EGFP mice at 4 vs. 16 months (two-tailed t-test). 