The Study of Antidepressive and Cognition Improvement Property of N-3 Fatty Acids on Metabolic Syndroms

Unipolar depression has been recognized as one of major diseases by WHO in the 21st century. The etiology of depression is complicated, many factors such as genetics, social stress, aging, and special physical status (pregnancy, metabolic syndrome, and trauma) that cause disease development. The aging process may contribute to nerve system dysfunction, memory and cognition decline and even depression. It has been suggested that n-3 polyunsaturated fatty acid (PUFA) defect is highly correlated to cognition and depression in animal study and clinical trial. And even in the populations suffer with metabolic symptoms. Elevated plasma or RBC n-3 PUFAs may contribute to recover of cognition, depression and even CVD. However, individuals suffer on the metabolic syndrome show poor cognitive function in midlife. Eicosapentaenoic acid (EPA) is good for depression improvement; however, docosahexaenoic acid (DHA) presents highly correlation with cognition and memory. Both EPA and DHA are n-3 PUFAs, DHA is major lipid component in brain, whereas EPA is a main source of eicosanoids synthesis. Thus, it is worthy to clarify the different functional properties between EPA and DHA. Thus, in our study, we plan to use in v^-vo experiments (midlife and aging animal models which suffer the metabolic syndromes) to explore the differences of n-3 PUFA on cognition and depression. We will evaluate the effectiveness of selected n-3 PUFAs on midlife or aging murine via forced swim test and Morris water maze test; meantime, we also assess the expression of BDNF and its receptor TrkB and protein expression of 5-HT2B and NMDA in certain brain areas in two years. The possible mechanism of n-3 PUFAs on improvement of cognitive function and depression will also be elucidated. Finally, we try to demonstrate the cognition impairment and depression under metabolic syndrome may recover by the various n-3 PUFAs.