Figure 7

Reversal by MgT treatment of behavioral and structural deficits in aged APPswe/PS1dE9 mice (Tg mice) and prevention of their premature death. (A) Experimental design to test whether MgT treatment can reverse behavioral deficits in aged Tg mice. (B) Recognition index of the novel object (Nov) and other familiar objects (Obj 13) during STM (left) and LTM (right) tests in the NORT task. WT (n = 10, ANOVA, STM: p < 0.0001; LTM: p < 0.0001) and untreated Tg (n = 8). (C) Same as (B) and on the same mice but NORT tests were re-conducted after MgT treatment was given to Tg mice for 1 month. ANOVA revealed significant differences in WT (n = 8, STM: p < 0.001; LTM: p < 0.05) as well as in MgT-treated aged Tg mice (n = 7, STM: p < 0.0001; LTM: p < 0.0001). Dashed lines represent chance levels of performance (25%). ANOVA was followed by Bonferroni's post hoc test. (D) Nest construction social behavior in WT (n = 10) and untreated Tg mice (n = 10). (E) Same as (D) and on the same WT (n = 7) and Tg (n = 6) mice, but after MgT treatment was given to Tg for 1 month. (F) Density of synaptophysin positive terminals (Syn Puncta). Data from untreated aged Tg mice (from Figure2B) were inserted (black bars) to show the effects of the 1 month treatment. ANOVAs (Table2) were followed by Bonferroni's post hoc test. Error bars show SEM. * p < 0.05, ** p < 0.01, *** p < 0.001. (G) Survival curves of WT (n = 65), Tg (n = 68) and Tg + MgT (n = 76) over 678days of lifespan (MgT treatment started at 6 months of age). Log-rank Mantel-Cox test revealed significant difference between Tg mice and WT (p < 0.05) as well as Tg + MgT (p < 0.01).