CHRONIC EFFECTS OF ORAL SODIUM FLUORIDE ON MODELS OF COGNITION IN ADULT MICE

Background: Sodium fluoride (NaF) is an inorganic fluoride salt used for the treatment of dental caries topically. It is also used in water fluoridation to prevent tooth decay. It has been reported to be associated with a lot of harmful effects, including neurotoxic effects. The aim of our study was to evaluate the chronic effects of NaF on the models of cognition in adult mice. Methods: Forty mice were randomly divided into four equal groups. NaF was administered dissolved in drinking water. The control group was Group I and received distilled water. Oral NaF at doses of 10mg/L, 20mg/L and 30mg/L respectively was given to Group II, Group III, Group IV. The influence of fluoride exposure on cognition was assessed using forced alternation test and spontaneous alternation test using Y-Maze. Evaluation was done at baseline, at the end of one month, two months and three months of NaF administration. Statistical analysis was done with the help of the Wilcoxon Signed Rank Test (within the group), Kruskal Wallis Test (between-group) and Mann-Whitney U Test. For all statistical analysis, p value<0.05 was taken as the threshold for statistical significance. Results: Animals receiving NaF at a dose of 10mg/L, 20mg/L and 30mg/L showed a significant decrease in the percentage of alternations in forced alternation test as compared to the control group with a p<0.01. Animals receiving NaF at a dose of 10mg/L, 20mg/L and 30mg/L showed a significant decrease in the percentage of alternations in spontaneous alternation test as compared to the control group with a p<0.01. Conclusion: Chronic use of oral NaF in adult mice may lead to cognitive impairment.