Fluoride Action Network


The aim of this research was to study the mechanism of the decreased learning and memory of rats with chronic fluorosis. Compared with controls, decreased learning and memory ability, lower levels of total antioxidant capacity (TAOC), and increased content of malondialdehyde (MDA) in brain tissues were observed in both male and female young adult rats after 6 months with either 5 or 50 mg NaF/L in their drinking water. Interestingly, the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in the brain were reduced more in the rats with the lower NaF concentration than in those with the higher concentration, thereby suggesting a paradoxical dose-response effect of F on these enzymes. The results indicate that the reduced learning capacity and memory ability of rats induced by F may be connected with increased oxidative stress and diminished cholinergic nervous system responses.