Effects of Aluminum chloride (AlCl3) on spatial memory: association with oxidative stress

The effects of chronic AlCl3 exposure on spatial memory in rats remain controversial. Since some toxic metals such as aluminum when entered the body, can contribute to diseases such as Alzheimer, in this study the time course effect of the systematically administered AlCl3 on the spatial memory retention in the Morris Water Maze was investigated. Rats were treated with AlCl3 (1 gr/lit) for two, four and eight week periods. Rats in all groups were trained for four days, each day included one block, and each block contained four trials. Test trials were conducted 48 hours after the completion of AlCl3 treatment. The results of our study show that AlCl3 increased the escape latency and the traveled distance by the AlCl3 treated rats in comparison to the controls, but no significant difference in the swimming speed between the two groups was observed. This findings suggests that AlCl3 has caused significant spatial memory retention impairment in the groups that received it for a period of eight weeks. Also the levels of plasma thiol groups and plasma antioxidant capacity showed a significant decrease in rats given AlCl3 for four and eight weeks in comparison with the control group. Our results also show that neurotoxicity which is caused by aluminum is associated with oxidative stress. Oxidative damage leads to formation of amyloid plaques in the nerve cells which in turn leads to decrease in the learning capability of the lab animals. Therefore, the results of our study provide a recommendation to people chronically exposed to Al, to consume fresh vegetables and fruits and/or take safe doses of antioxidant supplements to strengthen their defense mechanism against the antioxidants.