Changes in activation of the mammalian Target of Rapamycin (mTOR) signaling pathway. Representative immunoblots of PS2448-mTOR (289 kDa), total mTOR (289 kDa), PT389-p70S6K (70 kDa), total p70S6K (70 kDa) in cortex (A and B) and hippocampus (C and D) of wild-type (WT) mice and APPswePS1dE9 (APP) at 3, 6 and 12 months of age. Semi-quantitative analysis of immunoblot was performed using Gene Tools software (Syngene, Ozyme, Saint-Quentin-en-Yvelines, France). The immunoreactivity of protein was normalized to β-tubulin (55 kDa) immunoreactivity. The results are expressed as arbitrary units (% of WT). Results are mean ± SEM of 12 mice. Comparison between APP and WT mice at each age by a Mann-Whitney test: **
P < 0.01, ***
P < 0.001; comparison of the 3 classes of age (Kruskall-Wallis test) followed by two-by-two comparisons (Dunn’s multiple comparison test in APP mice): $$
P < 0.01 for 3-month old versus 6-month old APP mice, #
P < 0.05, ##
P < 0.01 for 6-month old versus 12-month old APP mice.