Effect Of Chronic Stress On Synapse-related Protein Expression In Hippocampus Of Rats

Objectives:This study aims to explore the expression of synapse-related protein under a chronic psychological stress and a chronic pain stress,including(1)Effects of chronic stress on behavioral changes and thresholds of hyperalgesia in rats;(2)Effects of chronic stress on the expression of synapse-related proteins in rat hippocampus;(3)The difference of left and right brains in rat hippocampal synapse-related protein expression under chronic stress conditions.Methods:Male Sprague-Dawley rats were randomly assigned to the control group,chronic psychological stress group,sham group,and chronic pain group.The chronic psychological stress model was established in the control group and the chronic psychological stress group to give rats 5 weeks chronic unpredictable mild stress(CUMS).Rats in the sham group and chronic pain group were treated with reserved nerve injury to establish a chronic pain stress model.During the establishment of the chronic stress model,observing the change of body weight,the sugar preference experiment,pain sensitivity threshold measurement was used to test whether the chronic stress model was successfully established.After behavioral experiments,further study of the effects of chronic stress on hippocampal synapse-related protein expression,western blotting was used to detect the changes of postsynaptic density protein 95,2',3'-Cyclic-nucleotide 3'-phosphodiesterase and synaptophysin in the hippocampus and whether there were differences in the expression of left and right hippocampus.Results:(1)Chronic stress induces changes in the behavior of rats and reduces the mechanical hyperalgesia threshold in rats;(2)chronic psychological stress caused a decrease in the relative expression of PSD95,CNPase and synaptophysin in the right hippocampus;(3)the influence of chronic psychological stress on the expression of hippocampal synapse-related proteins was significant in right brains than in left brains.Conclusions:(1)Chronic stress changes the behavior of rats and reduces the mechanical pain threshold in rats;(2)chronic psychological stress reduced the relative expression of synapse-related proteins in the right hippocampus of rats;(3)chronic stress affects hippocampal synapse-related proteins expression in rats and there is a difference in left and right brain.