Abstract

The protective role of vitamin E (Vit E) against neurotoxicity induced by fluorosis was investigated by using Sprague-Dawley (SD) rats fed with 50 ppm fluoride in drinking water for 10 months. Spatial learning and memory of rats were measured by the Morris water maze test; the expressions of M1 and M3 muscarinic acetylcholine receptors (mAChRs) at the protein level in the hippocampus and cortex were detected by immunohistochemistry; and the levels of O 2 •– and malondiadehyde (MDA) were evaluated by biochemical methods. The results showed that high fluoride inhibited learning ability and memory of the rats, reduced the protein expressions of both M1 and M3 mAChRs, and elevated the levels of O 2 •– and MDA in the rat brains. Interestingly, the treatment of Vit E prevented the increased production of O 2 •– and MDA in brains of the rats fed with high fluoride. In addition, Vit E attenuated the decreased learning ability and memory of the rats exposed to high fluoride, and the mechanism for this may involve the recovered expression of mAChRs resulting from the use of the antioxidant.