Effect of environmental enrichment on depressive-like behaviors induced bv chronic stress in rats / 中华行为医学与脑科学杂志

ABSTRACT

ObjectiveTo observe the effects of enriched environment on depressive-like behaviors induced by chronic stress in rats.MethodsAdult 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).ConclusionChronic stress can reduce depressive-like behaviors,and EE can restore depressive-like behaviors induced by chronic stress.