Evaluation And Mechanism Of Depression And Anxiety In Obese Mice Induced By High Fat Diet

Objective:Evaluating the changes of depression and anxiety like behavior in obese mice induced by high-fat diet,then analyzing the possible mechanisms involved in the experiment.Methods:Twelve age-matched C57 BL / 6 female mice were selected and randomly assigned to two groups fed with high fat diet and chow diet respectively for eight weeks.Weight changes were observed daily and intraperitoneal glucose tolerance experient(ipgtt)were performed at the end of eight weeks.After that using open field test and force swimming test and tail suspention test and sucrose consumption test and social test and elevated plus-maze test and light-dark box test snd novel object stimulation test to evaluate the depression and anxiety like behavior in mice.Then using Real-time PCR to analyze relative expression level of inflammatory and glutamate receptors and glucocorticoid receptor and neurotrophic and neuroplasticity gene in mouse prefrontal cortex and hippocampus.Results: Contrast to chow diet,high fat diet induced weight change was significantly increased and associated with impaired glucose tolerance.There are no difference in ambulatory distance between two groups in open field test,so body weight change can not be used as a parameter to affect the activity of mice.Total immobility duration in force swimming test and tail suspension test was prolonged and sugar consumption percentage which represent of pleasure was decreased,and the stay time of social test did not differ between two chambers,indicating that high fat diet induced obese mice with a depressive phenotype.In the elevated plus maze test,the duration ratio and entrance frequency ratios of open arms and closed arms in high fat induced obese mice was significant increased.The frequency and duration into the white box was increased.Both the results indicate that high fat diet induced obese mice with anxiety phenotypes.The results of Real-Time PCR indicates that high fat diet induced mouse IL-6 levels in PFC increased obviously,but Glu N2 A and Glu N2 B decreased,and TNF-?levels in hippocampus were significantly increased,the Arc gene expression levels were significantly increased in PFC and other gene expression level had no significant difference.Conclusion:High fat diet can induce the obese-depression related mice model,which provides a new carrier for the study of the relationship between obesity and depression.At the same time,the change of inflammatory cytokines IL-6,TNF-?and NMDA receptor may play an important role,and Arc gene as a neuroprotective genes in high fat diet induced obese mice model was higher is worth to discuss.