European Journal of Biomedical and Pharmaceutical Sciences

HISTOPATHOLOGICAL CHANGES IN CENTRAL NERVOUS SYSTEM OF RATS FOLLOWING ADMINISTRATION OF FLUORIDE

Shashi A* and Jatinder Kumar

ABSTRACT

Fluoride has the ability to interfere with the functions of the brain that causes impairment of central nervous system. In the present study young, healthy Wistar albino rats weighing 100-200 g were allocated to four groups. Group I was given 1 ml double distilled deionized water/kg body weight/day for forty days and kept as control. The remaining groups II, III and IV were treated with 100, 200 and 300 ppm of sodium fluoride/kg body weight/day via oral gavage for the same period. The rats were sacrificed and hematoxylin and eosin stained sections of cerebellum were studied for neuropathological alterations. In rat treated with 100 ppm sodium fluoride, the cerebellar cortex exhibited decrease in the number of Purkinje neurons. Some Purkinje neurons exhibited degeneration, distortion in the form of rounded, crescent and spindle shaped cell formation. Pyknosis of granule cells and atrophied nuclei of Purkinje neurons were seen in Purkinje neuron layer. In rat treated with 200 ppm sodium fluoride, neurofibrillary tangles in the granule layer and sign degenerative spaces around constricted Purkinje neurons were visible. Neuronophagia, pyknotic Purkinje neurons and loss of Nissl substance from neuroplasm were observed. The clumps of granular cells and degeneration in between granular cell layer were present. In cerebellar cortex of rat treated with 300 ppm sodium fluoride, the Purkinje neurons showed dot like nuclei. In the central medulla of white matter and granular layer, there were present fluid filled degenerating spaces with debris of dead granular cells and nerve fibers. In some Purkinje neurons, darkly stained, spindle formed nuclei were shifted to the periphery. Degenerative spaces in the Purkinje neuron layer, chromatolysis in the granule cells and perivascular edema around constricted blood capillaries were clearly observed. The neuropathological observations in cerebellar cortex of this study clearly reveal that the fluoride may be playing important role as causative agent for the neuronal cell damage and disruption of cerebellar integrity.

Keywords: Cerebellum, Cerebellar cortex, Neuropathology, Purkinje Neuron, Sodium fluoride, Wistar albino rat.