Histomorphological Changes and Cognitive Function in Fluoride and Arsenic Induced Injury to Hippocampus and the Cerebral Cortex in Wistar Rats

Suresh Tadipi, C. V. Raghuveer, K. V. Venkateshu, P. Kiranmayee


Fluoride and Arsenic are two inorganic contaminants found in drinking water, and ingestion of such drinking water may result in complicated adverse effects. This research aimed to study the effects of Fluoride and Arsenic alone and their co-exposure on the histomorphological changes in sub regions of the hippocampus and cerebral cortex and learning and memory ability in Wistar rats. One-month-old male Wistar rats 32 were randomly allocated and assigned to a Control group, Fluoride group, Arsenic group, and Fluoride + Arsenic group. The control rats were treated with potable water. The remaining rats were treated with 120 ppm of Fluoride and 70 ppm of Arsenic water. Hebb William’s Maze and T-Mazes have been used as learning and memory tests. Learning and memory ability declined in Arsenic and Fluoride + Arsenic-treated rats compared to Fluoride and Control rats. The assessment of histomorphological changes in the hippocampus and cerebral cortex by Cresyl violet stain. In the control group, neurons exhibited a clear nucleus and cytoplasm, In Arsenic and Fluoride + Arsenic-treated rats showed irregularly arranged cells and evidence of Karyopyknosis compared to Fluoride and Control rats. The hippocampus and cerebral cortex showed many vacuoles. The pyramidal cells were irregular in shape and had darkly stained nuclei, Granular cells were shrunken and deeply stained in Arsenic and Fluoride + Arsenic-treated rats compared to Fluoride and Control rats. Combined Fluoride and Arsenic exposure for long duration has damaging effects on the brain as resulted in diminished learning and memory ability and histomorphological changes compared to the effect of Fluoride and Control groups.


Keywords: Fluoride, Arsenic, hippocampus, cerebral cortex.



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