早年创伤性应激经历对成年大鼠前额叶和海马5-HT受体亚型的影响

Effects of Early-life Traumatic Stress Experience on the Expression of 5-HT Receptors in Rats' Prefrontal Cortex and Hippocampus

目的:研究早年创伤性应激经历对成年大鼠前额叶和海马5-HT1A和5-HT2C受体表达的影响。方法:33只雄性20日龄Wistar大鼠随机分为对照组、PTSD组和运动组,每组11只。以不可逃避的足底电击建立PTSD模型,以渐进性自主运动作为干预手段。采用旷场试验和高架十字迷宫评估行为学改变,采用免疫组化和Western Blot-ting检测前额叶和海马5-HT1AR和5-HT2CR表达变化。结果:与对照组和运动组相比,PTSD组在旷场试验中中央格停留时间、跨格数和直立次数明显减少;在高架十字迷宫试验中进入开放臂次数百分比,时间百分比明显降低。在免疫组化实验中,与对照组相比,PTSD组5-HT1AR在前额叶和海马表达均明显增加,运动组前额叶5-HT1AR表达显著低于PTSD组。与对照组和运动组比较,PTSD组5-HT2CR在前额叶和海马表达明显增加。在Western Blot-ting实验中,与对照组和运动组相比,PTSD组5-HT1AR在前额叶表达明显升高,5-HT2CR在前额叶和海马表达均明显升高。结论:早年创伤性应激导致成年大鼠明显的抑郁和焦虑症状,前额叶和海马5-HT1A和5-HT2C受体表达上调,渐进性自主运动可减轻应激导致的焦虑抑郁症状,可能是通过下调中枢5-HT受体亚型实现的。

Objective： The aim of the study was to investigate the expression of 5-HT receptors in rats prefrontal cortex（PFC） and hippocampus（HIP） after adolescent traumatic stress. Methods： 33 healthy Wistar male rats were randomly as-signed to control group, post-traumatic stress disorder（PTSD）group and exercise group（11 in each group）.The PTSD modelwas prepared by the inescapable electric foot shock stress. The anxiety-like and depressive behavior was evaluated by theelevated plus maze and the open-field test. The expression of the 5-HT1 AR and 5-HT2 CR were examined by WesternBlotting and Immunohistochemistry. Results： The PTSD group showed lower crossing and less time in the center and alsolower rearing compared to the control and exercise group in the open-field test, less time spent in the open arms and lessopen arm entries percentages in the elevated plus maze test. By Immunohistochemistry test and Western Blotting test, theexpression of 5-HT1 AR in the PFC was significantly increased in the PTSD group compared to both control group and exer-cise group. The expression of 5-HT2 CR in the PFC and HIP were both remarkably increased in the PTSD group. The con-trol group＇s expression of 5-HT1 AR in the HIP was significantly lower than the PTSD group in the Immunohistochemistrytest. Conclusion： Early life traumatic experience induces the depression along with anxiety symptoms,it also increases theexpression of 5-HT1 AR and 5-HT2 CR in the PFC and HIP. Progressive increasing exercise could effectively reduce therisk of stress impairment,which may be mediated by the down-regulation of 5-HT1 AR and 5-HT2 CR.