Fig. 5

The GES enhanced learning and memory performance of 5xFAD mice. The Morris Water Maze test was carried out as detailed in Materials and Methods (Fig. 1) for swimming efficiency and latency to the invisible escape platform in a 4-day training trial before (Wk 0) and after (Wk 4). The memory enhancement was assessed with the time percentage spent at the target quadrant (at which quadrant the platform was removed) in a 60-second probe trial, before and after GES. A-E. The swimming efficiency was enhanced in 25–200 µA GES groups. F-J. The latency to find the hidden platform was attenuated in 25–200 µA GES groups. K. The percentage time in the target quadrant of probe trials showed significantly improved memory in the 200 µA group. L. Representative swimming paths before and after the 4-week GES treatment. Data are mean ± SEM from 200 µA group (n = 7 mice), 50 µA group (n = 8), and sham group (n = 6 mice). Data are mean ± SEM from the sham (n = 6 mice), 25 µA (n = 8), 50 µA (n = 8), 100 µA (n = 6), and 200 µA (n = 7) groups. *P < 0.05 was considered as significantly different for after vs. before GES