丰富环境对慢性应激大鼠抑郁样行为的影响

目的 观察丰富环境干预对慢性应激大鼠抑郁样行为的治疗作用.方法 成年大鼠随机分为应激组( stress)和对照组(control),21d后给予丰富环境(EE)和标准环境(SE)干预28d.采用旷场试验、糖水偏爱试验和强迫游泳试验评估大鼠抑郁样行为.结果 (1)旷场试验:与control组比较,stress组大鼠穿越格数、直立次数和修饰次数减少[分别为( 13.88±4.38)格,(45.00±10.19)次,(9.13±2.54)次；(16.38±4.11)格和(4.78±1.39)次,(10.51±2.52)次；n=8),有显著性差异(均P＜0.01)；而stress+ EE组大鼠穿越格数和直立次数较stress+ SE组增加[分别为(41.61±10.53)格,(26.25±6.18)次和(16.79±3.49)格,(11.25±3.12)次；n=8),有显著性差异(P＜0.01,P＜0.05).(2)糖水偏爱试验:与control组比较,stress组大鼠糖水消耗量和偏爱率％下降[分别为(5.22±0.94)％,(10.61±2.59)％和(49.11±6.77)％,(63.38±8.36)％；n=8),差异有显著性(均P＜0.01).(3)强迫游泳试验:与control组比较,stress 组大鼠静止时间明显增加[(19.5±5.43)s,(12.75±3.9)s；n=8；P＜0.05]；而stress+ EE组大鼠静止时间较stress+ SE组明显减少[(10.25±3.57)s,(17.75±5.45)s; n=8; P＜0.05].结论 慢性制动应激可以导致抑郁样行为,而丰富环境干预可以改善慢性应激导致的抑郁样行为.

Effect of environmental enrichment on depressive-like behaviors induced bv chronic stress in rats

Objective To observe the effects of enriched environment on depressive-like behaviors induced by chronic stress in rats.Methods Adult rats were randomly divided into stress group and the control group,then after 21 days of stress,rats were raised in an enrich environment (EE) or standard environment (SE)for 28 days.Open field test,forced swimming test and sucrose preference test were used to detect depressive-like behavior in rats.Results ( 1 ) Open field test showed that grid crossing,standing and rearing in stress ( no gap)rats were significantly reduced ( 13.88 ±4.38 vs 45.00 ± 10.19,9.13 ±2.54 vs 16.38 ±4.11 and 4.78 ± 1.39vs 10.51 ± 2.52 ; n =8 ; P＜ 0.01 respectively) ; but grid crossing and standing in stress + EE rats were significantly increased than stress + SE rats (41.61 ± 10.53 vs 26.25 ± 6.18 and 16.79 ± 3.49 vs 11.25 ± 3.12 ; n =8 ; P＜0.01 and P＜0.05 respectively).(2) Sucrose preference tests showed that sucrose consumption and sucrose preference％ in stress ( no gap) rats were significantly decreased than those in the control group ( 5.22 ± 0.94 vs 10.61 ±2.59 and (49.11 ±6.77)％ vs(63.38 ±8.36)％ ; n=8; P＜0.01 respectively).(3) Forced swimming test showed that immobility time was increased in stress ( no gap) rats ( ( 19.5 ± 5.43 ) s vs ( 12.75 ± 3.9 ) s; n =8 ; P ＜ 0.05 ) and was restored by EE compared to SE rats ( ( 10.25 ± 3.57) s vs ( 17.75 ± 5.45 ) s; n =8 ; P ＜ 0.05).Conclusion Chronic stress can reduce depressive-like behaviors,and EE can restore depressive-like behaviors induced by chronic stress.