Morris water maze

The cognitive function of the animals was evaluated using a Morris water maze as previously described [25]. The Morris water maze (MWM) test was administered before treatment (to confirm behavioral deficits in APP/PS1 mice) and after the HT, MEM and saline treatments. In brief, mice can escape onto the platform within 60 s and then stay on the platform for at least 5 s during acquisition phase trials (days 1–5). If the mice failed to find the platform within the permitted 60 s, they were manually placed on the platform for 30 s so that they could recollect the location of the platform, and the latency was recorded for 60 s. The escape distance and escape latency were analyzed by Any-maze software (Stoelting, USA). On the 6th day, the platform was removed from the water maze, and the mice were released to swim freely for 60 s. The number of times they crossed the target platform and the time spent in the target quadrant were automatically recorded by the video/computer system.