Fluorosis, as a consequence of exposure to high amount of fluoride is a serious
public health problem in many parts of world. Fluoride can cause severe damage to the dental and skeletal systems, and is known to be an endogenous neurotoxin. In the present study, Wister albino rats of weighing100-200 gwere given 100, 200 and 300 ppm of sodium fluoride per kg body weight per day for forty conjunctive days while control were given 1 ml double distilled deionized water per kg body weight per day for same duration. The rats were sacrificed under ether anesthesia after fluoride treatment and cerebrum was carefully removed and fixed in Bouin’s fluid for neuropathological examination. Neuropathological examinations of cerebrum in fluoride treated rat revealed that some pyramidal neurons showed chromatolysis and were shrunken with vacuolation around them. The nuclei of many pyramidal neurons were eccentric in neuroplasm, irregular and spindle shaped, others were exhibiting necrosis and some presented dark constricted dot like structure. In few pyramidal neurons, the nuclei appeared as eosinophilic or red. Some pyramidal neurons in certain region showed hyperchromatic and hypertrophic nucleus that was filling entire neuroplasm. The granule cells were aggregated in the form of clumps, and neuropil exhibited heterogeneous acidophilic masses containing fragments of nuclei and clear halos. Many granule cells were swollen in shape and size while some appeared darkly stained with dot like shrunken nuclei and empty spaces around them. In cerebral cortex of fluoride treated rat, the blood capillaries were congested with narrow lumen and perivascular empty spaces.