中文摘要：

目的探讨慢性不可预知轻度应激对大鼠旷场行为的影响。方法将24只雄性SD大鼠随机分为3组：A为对照组、B为应激组、C为应激＋用药组，每组8只。A组不予以刺激，B、c两组采用慢性不可预知轻度应激（CUMS）模型的实验方法，每日予以1～2种刺激；A、B两组每日腹腔注射生理盐水2ml，c组每日腹腔注射西酞普兰2ml（10mg／kg）。实验为期6周，每周为大鼠称重，每3周测大鼠的糖水偏爱性、旷场试验评价大鼠行为，6周后施行安死术。结果B组及C组与A组相比，体重增长明显较少（均值分别为153．05g、127．69g、232．572）；B组与A组及c组比较，糖水偏爱度显著降低（均值分别为60％，73％，71％）；且B组大鼠在旷场中的总移动里程、总运动时间、越线次数等行为指标增大，而另两组在这些指标上均减小。结论慢性不可预知轻度应激诱发大鼠抑郁症状的同时，可能导致其行为增多等类焦虑症状。

英文摘要：

Objective To explore the influence of chronic unpredictable mild stress（CUMS） on rats＇ open field behaviors. Methods Twenty-four SD rats were randomly assigned to three groups： A is control group, B is CUMS group, C is CUMS ＋ citalopram group. Rats in group B and C were subjected to the CUMS schedule; Group A and B were submitted to administration with saline, while group C was pretreated with citalopram （CTP, 10 mg/kg, i.p.） every day. Body weight was measured every week. Sucrose preference and open field test were evaluated every three weeks. Animals were sacrificed after 6-week CUMS trial. Results CUMS rats, either with or without citalopram, weight gain was reduced compared to control （average 153.05 g, 127.69 g, 232.57 g, respectively）. Rats in CUMS group had lower sucrose preference than which in control group and CUMS ＋ citalopram group （average 60%, 73% and 71%, respectively）. However, several behavioral indicators in open field, including total distance travelled, total mobile time and number of line crossings, were increased in CUMS treated rats, while which in control and CUMS ＋ citalopram rats declined. Conclusion Chronic unpredictable mild stress may lead to rat＇s depression and elicit simultaneously some anxiety-like symptoms, such as increased motor activity.