慢性炎性痛模型大鼠诱发焦虑抑郁样情绪行为观察

Observation of the anxiety and depression-like behavior induced by chronic inflammatory pain in rats

目的动态观察弗氏完全佐剂(CFA)诱导慢性炎性痛模型大鼠痛情绪的改变情况,探索慢性炎性痛模型大鼠诱导焦虑、抑郁情绪的时间差异性。方法所有实验大鼠随机分为空白对照组和模型对照组,模型对照组于足底注射CFA建立慢性炎性痛模型。动态观察各组大鼠造模前、造模后1,3,7,18和26 d机械缩足阈变化(PWTs);观察造模后28 d旷场实验(OF),29 d高架O迷宫实验(EZM),30 d新奇食物抑制实验(NSF),造模后12,20和31 d大理石掩埋实验(MBT),造模后17,25和35 d糖水偏爱度实验(SPT)中大鼠行为改变情况。结果造模后1 d,模型对照组大鼠PWTs显著降低(P<0.01),且在整个实验过程中均显著低于空白对照组(P<0.01)。模型对照组在OF中较空白对照组大鼠的中央区运动距离、中央区停留时间、中央区进入次数显著减少(P<0.01);在EZM中较空白对照组大鼠的开放臂运动距离,开放臂停留时间,开放臂进入次数显著减少(P<0.05);在NSF中较空白对照组大鼠摄食潜伏期明显增加(P<0.05),且食物消耗量无明显差异(P>0.05);而MBT仅模后31 d,模型对照组较空白对照组大鼠大理石埋藏数量显著增加(P<0.05);SPT中模后各时间点模型对照组与空白对照组大鼠比较均无明显差异(P>0.05)。结论CFA诱发的慢性炎性痛模型大鼠在4周后可出现多种与焦虑样情绪相关的动物行为改变,但在5周内均并未观察到与抑郁样情绪相关的动物行为改变。

Objective To dynamically observe the temporal differences of anxiety and depression-like behavior in rats with chronic inflammatory pain induced by complete Freund’s adjuvant(CFA).Methods All rats were randomly divided into control and model groups.The model group rats was injected with CFA into the hind paws to establish the chronic inflammatory pain model.We dynamically observed the changes of paw withdrawal thresholds before modeling and at 1,3,7,18,and 26 days after modeling.In addition,behavioral changes were observed in an open field test at 28 days,in an elevated zero maze test at 29 days,in a novelty-suppressed feeding test at 29 days,and in a marble-burying test at 12,20,and 31 days,as well as through a sucrose preference test after modeling at 17,25,and 35 days.Results Compared with the control group,the paw withdrawal threshold of the model group significantly decreased after 1 day(P<0.01)and was significantly lower than the control group throughout the experiment(P<0.01).Compared with the control group,the distance in the central area,time in the central area,and number of central zone entries of the model group were significantly reduced in the open field(P<0.01).Compared with the control group,the distance in open arm,time in open arm,and number of the open arm entries of the model group were significantly reduced in the elevated zero maze(P<0.05).The latency of food of the model group was significantly increased(P<0.05),and there was no significant difference in food consumption in the novelty-suppressed feeding(P>0.05).In the marble-burying test,the number of buried marbles in the model group increased significantly compared with the control group(P<0.05)31 days after modeling.There was no significant difference between the control group and the model group at any time point in the sucrose preference test(P>0.05).Conclusions Chronic inflammatory pain induced by CFA can lead to a variety of changes in the anxiety-like behavior of animals after 4 weeks,while no changes in the depression-like behaviors of animal was seen before 5 weeks.