The effect of selenium on the morphological changes in the hippocampus and cerebral cortex of scopolamine induced alzheimer's type dementia rat model by histological analysis

Alzheimer's Disease (AD) is one of the neurodegenerative diseases with significant memory loss and it is very common worldwide. Amyloid plaques and neurofibrillary tangles which are important hallmarks of the disease result in progressive neuronal loss in hippocampus and cerebral cortex regions in the brain. In recent years, various studies demonstrates that selenium is one of the important compounds that can be promising effects on AD pathology. Selenium affiliates the active sites of catalytic enzymes which are responsible for the protection of cells from oxidative damage. In this study, the effect of selenium on the hippocampus and cerebral cortex was evaluated in scopolamine-induced Alzheimer's rat model to examine morphological changes. It is hypothesis that selenium has a protective effect in this model.It was observed that the scopolamine substance caused a loss of locomotor movement like Alzheimer's, and it was understood that the selenium substance caused a slight improvement in these movements. Hematoxylin, eosin, cresyl violet and silver staining were used to observe pathological findings, and as expected, less pathological findings were observed in the selenium treatment group compared to the scopolamine group. H-Scores were calculated in iNOS, Amyloid-Beta immunohistochemistry staining, and there are significant differences between the results of the scopolamine and control groups (p<0.05, p<0.05).Amyloid-Beta immunohistochemistry staining showed intense amyloid plaque formation in the scopolamine group and rare amyloid plaque formation in the test group, but no statistical differences (p>0.05) were observed between the groups whose H-Scores were calculated because of VEGF immunohistochemistry staining. Finally, the apoptotic index was calculated with the TUNEL experiment, highest values were obtained in the scopolamine group, second highest in the test group, lowest in the control and selenium groups(p<0.05). As a result, as anticipated in this study, selenium caused an improvement in Alzheimer's model pathology simulated by scopolamine according to antioxidant role of selenium.