| Summary: | 碩士 === 東海大學 === 食品科學系 === 98 === Depression is a prevalent psychiatric disorder. World Health Organization (WHO) suggests that the depression is one of major diseases in the twenty-first century. Epidemiological studies show that supplementation with omega-3 polyunsaturated fatty acids can improve clinical outcome of depression patients. In contrast, diet deficient of omega-3 polyunsaturated fatty acids exacerbates clinical outcome. These observations suggest that the alteration of omega-3 polyunsaturated fatty acid content may have a role in the induction and augmentation of depression. While the action mechanisms of omega-3 polyunsaturated fatty acid supplementation in the physiological processes have been widely studies, the effect and potential action mechanisms of omega-3 polyunsaturated fatty acid deficiency on neurobehavior remain largely unclear. This study was designed to investigate whether supplementation with omega-3 polyunsaturated fatty acid deficient diet alters animal neurobehavior and what is the potential action mechanism, focusing on depression-related changes. Rats fed with omega-3 polyunsaturated fatty acid deficient diet showed prolonged immobility time in tail suspension test and forced swimming test, indicating a depression-like behavior. In comparing with control normal diet, rats fed with omega-3 polyunsaturated fatty acid deficient diet showed decreases in brain weight, neuronal number, and NeuN and CNPase protein expression but increase in GFAP protein expression. The BrdU incorporation assay showed a decreased number of proliferating cells in omega-3 polyunsaturated fatty acid deficient diet-fed animals. Western blot analysis revealed that rats fed with omega-3 polyunsaturated fatty acid deficient diet expressed lower levels of Nestin, Klf4, and Sox 2 protein in cerebral cortices. Besides, a decreased level of BDNF was detected in cerebral cortices and plasma when rats were fed with omega-3 polyunsaturated fatty acid deficient diet. In conclusion, our results show that supplementation with omega-3 polyunsaturated fatty acid deficient diet may cause rats expressing depression-like behavior. This diet-induced behavioral alteration was accompanied by decreased number of endogenous neural stem cells, decreased neurogenesis, and decreased BDNF expression.
|
|---|
