Figure 1.

Evaluation of the spatial reference memory of 12-month-old wild-type C57BL/6 mice and transgenic APP/PS1 mice using the radial arm water maze (RAWM) test. C57BL/6 mice and transgenic APP/PS1 mice were divided into three study groups, i.e., the non-transgenic control (NTG), transgenic APP/PS1 (TG) control, and TG MIT treatment groups, and treated with vehicle control or MIT once daily for 3 months. The cognitive performances of NTG and TG mice were presented as trials of the number of errors and escape latency. Both parameters demonstrated the difference in cognitive performance at the learning phase—Trial 1—and at the memory phase—Trial 5. The values are expressed as means ± standard deviation (SD) (N = 9 for the NTG control group, N = 10 for the TG control groups, and N = 9 for the TG MIT treatment group). SD is denoted by error bars. A comparison of (A) baseline number of errors, (B) baseline latency, (C) the post-treatment number of errors, and (D) the post-treatment latency between Trial 1 and Trial 5 demonstrated a significant decrease in baseline number of errors (p < 0.05), post-treatment number of errors (p < 0.01), and latency (p < 0.05) in NTG control mice; a significant decrease in the post-treatment number of errors (p < 0.05) in TG control mice; and a significant decrease in the post-treatment number of errors (p < 0.01) and latency (p < 0.05) in MIT-treated TG mice. One-way ANOVA followed by a Tukey’s post hoc multiple comparison test showed that there was no statistically significant difference in the number of errors and latency between the three study groups. * p < 0.05 and ** p < 0.01 compared with Trial 1 using the paired-sample t-test.