束缚应激与单程长时应激致小鼠焦虑障碍的应激参数比较与优化

Parameters of restraint stress and single prolonged stress for modelling anxiety disorder in mice:comparison and optimization

目的通过比较与优化束缚应激(restraint stress,RS)和单程长时应激(single-prolonged stress,SPS)法致小鼠焦虑障碍的应激参数,筛选一种重复性好、用时少且操作简易的方法建立小鼠焦虑障碍模型,为深入研究焦虑障碍的发病机制提供可靠的实验动物模型建立方法。方法①将C57BL/6J雄性小鼠随机分为空白对照组、RS 14 d组和SPS 14 d组。RS造模方法为:每天给予RS 2 h,连续应激14 d;SPS造模方法为:每天先给予小鼠2 h RS,之后立即强迫游泳20 min,休息15 min后用异氟烷麻醉放回原笼,连续应激14 d。②将C57BL/6J雄性小鼠分为空白对照组和不同时长RS(2、4、6或8 h/d)7 d组;RS造模方法为:每天分别给予RS 2、4、6或8 h,连续应激7 d。造模期间每天观察小鼠体质量的变化。造模结束后,通过旷场实验检测小鼠自主活动和在中心区域停留时间,高架十字迷宫实验检测小鼠进入开放臂的次数和在开放臂内停留时间,观察小鼠的焦虑样行为变化。结果①与空白对照组相比,RS 14 d组和SPS 14 d组小鼠在应激第7~14天期间体质量均显著降低(P<0.01),其他各项行为学指标无明显变化;②在2、4、6或8 h/d不同时长RS连续应激7 d实验中,与空白对照组相比,RS 8 h组小鼠应激第7天的体质量显著降低(P<0.01),RS 2、4、6和8 h组小鼠应激第7天的自主活动和在旷场中心区域停留时间无明显变化,RS 2、4和6 h组小鼠在应激第7天高架十字迷宫内停留时间显著下降(P<0.05)。结论每天RS 2、4或6 h连续应激7 d可能成功建立小鼠焦虑障碍模型,其中每天RS 2 h用时少、重复性好、稳定性高,是理想的建立焦虑障碍模型的应激参数。

Objective To establish a simple and feasible method for modelling anxiety in mice,with good repeatability and stability,via the comparison and optimization of parameters of the restraint stress(RS)and single-prolonged stress(SPS)to create the mouse anxiety model and provide a reliable animal modelling method for further studies on the mechanism of anxiety disorders.Methods ① Male C57 BL/6 J mice were divided into the control group,the RS 14 d and SPS 14 d groups. The RS 14 d modelling procedure was as follows:the mice were restrained 2 h a day for continuous 14 days. The SPS model procedure was as follows:the mice were subjected to the following cycle of stress every day for continuous 14 days,restraining for 2 h,immediate forced-swimming for20 min,resting for 15 min,and then returning to the original cage after isoflurane anaesthesia.② Male C57 BL/6 J mice were divided into the control group and the RS(2,4,6 or 8 h/d)7 d groups,and the RS 7 d modelling was performed as restraining 2,4,6 or 8 hours a day for continuous 7 days. The changes in the body mass of mice were examined every day during the modelling time periods.At the end of modelling,the locomotor activity and residence time in the central area were determined by the open field test. The elevated plus maze test was used to detect the numbers of entries into and the residence times in the open arms,to evaluate the anxietylike behavior of mice. Results ① Compared with the control group,the body mass of mice was significantly decreased during the 7 th to 14 th days both in the RS 14 d group and the SPS 14 d group(P<0.01). There was no significant difference in anxiety-like behavior.② In the RS(2,4,6 or 8 h/d)7 d test,compared with the control group,the body mass of mice was significantly decreased in the8 h/d RS group(P<0.01)on the 7 th day. There was no significant difference in the locomotor activity and the residence time in central area on the 7 th day between the control group and all of the 2,4,6 and 8 h/d RS groups in the open field test. However,the residence time in the open arms was significantly lower in the 2,4 and 6 h/d RS groups(P<0.05)than in the control group in the elevated plus maze test. Conclusion RS 2,4 or 6 h/d for continuous 7 days could successfully create the anxiety mouse model,and the 2 h/d RS appeared to be best for modelling with the short running time,good repeatability and higher stability.