The Effect of Chronic Exposure To Fluorine and 7,12-Dimethylbenz(a)anthracene on Anxiety, Locomotor Activity, Spatial Learning, and Memory Consolidation in Rats

Abstract

In this study, the effect of fluorine, which is known to cause chronic toxication, and 7,12-dimethylbenz(a)nthracene (DMBA) on anxiety, locomotor activity, spatial learning, and memory consolidation in rats were investigated. Ninety adult Wistar albino male rats, weighing 150-200 g, were divided into 9 groups of 10 animals and treated for 90 days with fluoride (F), the ion of fluorine, in drinking water in the form of sodium fluoride (NaF) and weekly oral DMBA (10 mg/kg bw/po/weekly) in a sesame oil vehicle, in the following manner: group 1: 0 ppm F, 0 mg/kg bw DMBA (control); group 2: sesame oil weekly (vehicle control); group 3: 1 ppm F; group 4: 15 ppm F; group 5: 30 ppm F; group 6: DMBA; group 7: 1 ppm F and DMBA; group 8: 15 ppm F and DMBA; and group 9: 30 ppm F and DMBA. Tests for anxiety (elevated plus maze), locomotor activity (rotarod), and spatial learning and learning consolidation (Morris water maze) were administered to rats at the beginning and at the 30th, 60th, and 90th days of the study. The results showed that anxiety was increased by F at a low dose and DMBA, and decreased by high dose F. Locomotor activity was increased by F and decreased by F+DMBA. DMBA could either increase or decrease motor activity depending on the time of assessment. Spatial learning and memory consolidation were decreased by both F and DMBA. After considering these results, we plan to conduct further studies to clarify the mechanisms underlying these neurotoxic effects of fluorine and DMBA.