束缚应激对局灶性脑缺血小鼠行为的影响

目的观察束缚应激对局灶性脑缺血模型小鼠运动行为的影响。方法采用阻断左侧大脑中动脉（MCAO）缺血／再灌注小鼠模型，缺血后1周开始束缚应激（每天2h，共2周），应激结束后即行抑郁行为测试。结果束缚应激使局灶性脑缺血小鼠的自发运动明显减少，蔗糖水偏好比降低，而强迫游泳不动时间显著延长，与正常对照组比较差异显著（P〈O．01）。结论施加束缚应激后，局灶性脑缺血小鼠出现明显的抑郁行为，可考虑将其作为一种脑卒中后抑郁（PsD）动物模型，为进一步研究其生物学机制创造条件。

Effects of restraint stress on behaviors of mice with focal cerebral ischemia

Objective To evaluate the effects of restraint stress on behaviors of mice with focal cerebral ischemia. Methods Male mice were first subjected to left middle cerebral artery occlusion/reperfusion. Repeated restraint stress (2 hours/day for 2 weeks) was given from 1 week after surgery. At the end of stress scheme, sucrose solution consumption test, open-field test and forced swimming test were performed. Results Spontaneous locomotor activity and coordination test were decreased to the lowest level on the 1st day after MCAO compared with the baseline values before surgery (P<0.01). A quick improvement in motor functions was observed from the 2nd day to the 4th day after surgery. The motor functions on the 5th day showed no statistically significant differences compared with the baseline values. The mice with MCAO surgery when subjected to restraint stress showed significant decreased open-field activities and preference for the sucrose solution, exhibiting the characteristic of decreased responsiveness to rewards and explorative behaviors to a novol environment. Furthermore, there was a significant increased restriction in activity in forced swimming test in the mice with MCAO surgery when subjected to restraint stress compared with that in the control animals (P<0.01). Conclusion The mice with MCAO surgery subjected to restraint stress show anhedonia and decreased activities, and this may represent an animal model of post-stroke depression for further study of its underlying biological mechanism.