The pilot study is conducted using 30 adult albino rats (200-250gm). They were divided into one control and one experimental group. Group 1 is Control (Ctrl), which received food and water adlibitum, experimental group received, 20 ppm of sodium fluoride (NaF) for 7 weeks. The body weights and physical activity was significantly reduced in experimental group, whereas fluoride levels of hippocampus, was greatly increased. Light microscopy of the hippocampus, showed reduced neuronal density more pronounced in the CA3 region of hippocampus. Neuronal density was reduced to 84.2 cells/cu mm in experimental group as compared to 132.2 cells/cu mm in control.