丰富环境对社会隔离小鼠焦虑、抑郁情绪和认知功能的影响

Effects of Environmental Enrichment on Anxiety,Depression and Cognitive Function in Socially Isolated Mice

目的:探讨不同饲养环境对社会隔离小鼠焦虑与抑郁情绪和认知功能的影响。方法:将出生后21 d的昆明小鼠随机分为对照组、模型组和治疗组,每组8只;对照组以每笼4只饲养于标准环境,模型组、治疗组以每笼1只分别饲养于标准环境、丰富环境;4周后行开放旷场实验、高架十字迷宫实验、悬尾实验、强迫游泳实验和Morris水迷宫实验,观察小鼠自主活动度、焦虑、抑郁样行为和学习记忆能力。结果:与模型组小鼠比较,(1)治疗组小鼠运动总距离缩短[(3055.41±210.78)vs(2812.19±166.53)cm,P<0.05];(2)治疗组小鼠进入中央区次数[(19.38±2.33)vs(28.63±2.26)次]、中央区停留时间[(35.62±2.65)vs(55.01±6.34)s]、进入开臂次数[(3.50±1.31)vs(7.13±0.64)次]和开臂停留时间[(13.27±1.06)vs(16.73±1.14)s]增多,差异均具有统计学意义(P<0.05);(3)治疗组小鼠悬尾累积不动时间[(68.47±15.29)vs(29.74±4.75)s]和强迫游泳累积不动时间[(127.21±20.59)vs(70.31±12.16)s]均缩短(P<0.05);(4)治疗组小鼠第3天逃避潜伏期[(48.28±3.17)vs(45.50±6.60)s]缩短,第4天[(43.84±5.00)vs(32.86±4.79)s]、第5天[(36.57±5.13)vs(25.76±5.16)s]潜伏期明显缩短(P<0.05),第6天撤掉平台后在目标象限停留时间[(33.47±3.24)vs(42.89±3.89)s]和穿越平台次数[(1.63±0.52)vs(2.63±0.74)次]增多(P<0.05)。结论:丰富环境饲养可减少社会隔离小鼠自主活动度,减轻焦虑、抑郁样行为,改善学习记忆能力。

Objective:To investigate the effects of different rearing environments on anxiety,depression,and cognitive function in socially isolated mice.Methods:Kunming mice(21 days of age)were randomly divided into the control group,model group,and treatment group,with 8 mice in each group.The mice in the control group were raised in the standard environment with 4 mice per cage.The mice in the model group and treatment group were raised in the standard environment and environmental enrichment respectively with 1 mouse per cage.The open field test(OFT),elevated plus maze test(EPMT),tail suspension test(TST),forced swimming test(FST)and Morris water maze test(MWMT)were carried out to observe the autonomic activity,anxiety,depression and learning and memory ability after 4 weeks.Results:(1)Compared with the model group,the total distance of movement in the treatment group was significantly shortened(P<0.05).(2)Compared with the model group,the number of central zone entries,the time in the central zone,the number of open arm entries,and the time in open arm in the treatment group were increased significantly(P<0.05).(3)Compared with the model group,the cumulative immobility time in TST and the cumulative immobility time in FST in the treatment group were significantly shortened(P<0.05).(4)Compared with the model group,the escape latency on the third day was shortened,and the escape latency on the fourth day and fifth day were significantly shortened.Compared with the model group,the time spent in the target quadrant and the number of times crossing platform in the treatment group were significantly increased after the platform was removed on the sixth day(P<0.05).Conclusion:EE exposure can reduce autonomic activity,alleviate anxiety-and depression-like behavior,and improve the learning and memory ability of socially isolated mice.