Effects of running on excitatory synapses in medial prefrontal cortex in rat model of depression
Objective:To precisely and quantitatively study the effects of running exercise on the number of spinophilin(Sp+)excit-atory synapses in the medial prefrontal cortex(mPFC)in a rat model of depression induced by chronic restraint stress(CRS).Methods:After adaptive feeding and baseline saccharin preference testing,54 male Sprague-Dawley rats were randomly divided into three groups:control group,CRS depression model group,and model+running group.The model+running group had 4-week running exercise since the 5th week of restraint.Then behavioral tests were performed for each group.The changes in Sp+excitatory synapses in mPFC were measured quantitatively and precisely by immunohistochemistry and modern stereology.Results:Compared with the control group,the depression model group showed a significantly lower saccharin preference[(97.14±2.64)％vs.(89.62±6.05)％,P=0.002],a significantly slower increase in body weight,a significantly longer immobility time in the forced swimming test,and a signifi-cantly longer latency to eat in the novelty-suppressed feeding test.Compared with the depression model group,4-week running signifi-cantly increased saccharin preference[(89.30±5.06)％vs.(97.30±2.08)％,P=0.018],and significantly shortened the immobility time of the forced swimming test and the latency to eat in the novelty-suppressed feeding test.The stereology results revealed a signifi-cantly less total number of Sp+excitatory synapses in mPFC in the depression model group than in the control group[(9.98±0.35)×108 vs.(11.50±1.27) × 108,P=0.013];and running exercise significantly reversed the decrease in the total number of Sp+excitatory synapses in mPFC in depressive rats[(11.30±1.21)×108,P=0.003].Conclusion:Modulating the number of Sp+excitatory synapses in mPFC may be one of the neurobiological bases for running to relieve depression.
万方数据
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