Spatial learning and memory were tested with the MWM (Shanghai Jiliang Software Technology Company, Shanghai, China) 6 days before sacrifice. The maze consisted of three parts: a black circular pool with a diameter of 160 cm and depth of 45 cm; a camera system tracking the rats’ movement; and software for calculating parameters such as escape latency and the amount of time spent in the target quadrant. The pool was filled with water at 23°C ± 1°C and a platform was installed 1–2 cm below the water surface. The test comprised two phases: the place navigation test for five consecutive days, and the spatial probe test on day 6. In the first phase, the rat was placed in different quadrants of the pool on each day and allowed to search for the platform, with the camera and software system recording the rat’s swimming path. If the rat failed to locate the platform within 120 s, it was guided to the platform and allowed to remain there for 20 s. In this case, the escape latency was recorded as 120 s. For the spatial probe test, the platform was taken away. The experimental animals were placed in the water diagonally across from the original platform and allowed to search for the platform for 120 s. The number of platform crossings and the amount of time spent in the target quadrant were recorded.