Figure 1. Hyperglycemia exacerbates the cognitive damage in T2DM rats. (A) The escape latency (EL) of the Morris water maze of three groups is not significantly different on the 1st-2nd day (P > 0.05). From the 3rd to 5th day, there is a significant difference of EL between the DE and CG groups, as well as the DM group (P < 0.05). In the entire process, there is no significant difference between the DM and CG groups. (B) There is a significant difference in the distances across the platform between CG and DM groups, as well as the DE group (P < 0.05), whereas no significant difference is evident between the DM group and the DE group. (C) The number of rats crossing the platform among the three groups shows a decreasing trend, with no statistical significance between Con and DM (P > 0.05), but there is a significance between Con and DE (P < 0.05). (D) The Morris water maze tests show a confusing trajectory in the DE group, which makes it difficult for rats to find the platform. However, the trajectory of the CG and the DM group is clear and they both directly travel to the platform. Data are presented as the mean ± SD (n = 3 per group). * P < 0.01 vs. control group, ** P < 0.05 vs. the control group, n = 5 for each group.