Effects of Al (2 mg/kg) and melatonin (4 mg/kg) on memory performance measured in MWM test in male Wistar rats. (A) Latency to reach the hidden platform on each of the 4 days of learning phase. (B) Percentage of time spent in the correct quadrant. Results are represented as mean ± SEM. *p < 0.05 vs. control group; and #p < 0.05 vs. Al-treated group.