自发活动实验在小鼠全脑缺血后功能损伤评价中的应用

Application of locomotor activity test to evaluate functional injury after global cerebral ischemia in C57BL/6 mice

目的：了解自发活动实验在小鼠全脑缺血后功能损伤评价中的意义.方法：采用双侧颈总动脉阻断30 min建立C57BL/6小鼠全脑缺血模型,缺血对照组和米诺环素组术后腹腔注射生理盐水或米诺环素（45 mg/kg）,每天1次,持续到缺血后第6天.术后第6天进行开场实验,记录1h内小鼠的自发活动.以自发活动总路程、中央路程、周边路程、中央路程比值、周边路程比值、中央时间和周边时间为指标,评价C57BL/6小鼠全脑缺血后自发活动行为的变化特点.采用尼氏染色检测小鼠海马CA1区、皮层和纹状体区神经元存活情况.结果：C57 BL/6小鼠全脑缺血后在开场实验中的总路程、中央路程和中央时间均较假手术组增高（P＜0.05）,周边时间较假手术组减少（P＜0.05）;米诺环素可缩短小鼠的中央路程和中央时间,增加周边时间（P＜0.05）.小鼠全脑缺血后海马CA1区、皮层和纹状体区神经细胞损伤明显,米诺环素可显著改善海马CA1区和纹状体区神经细胞损伤（P ＜0.001和P＜0.05）.结论：自发活动实验可作为客观评价小鼠全脑缺血后功能损伤的行为学实验方法,其中央路程和中央时间可作为定量评价指标.

Objective：To evaluate the application of locomotor activity test in functional injury after global cerebral ischemia （GCI） in C57BL/6 mice.Methods：GCI was induced by bilateral carotid arteries occlusion for 30 min in C57BL/6 mice.Mice were divided into sham group,GCI group and minocycline group.Saline or minocycline （45 mg/kg） was i.p.injected once daily for 6 d after ischemia.At Day 6 after ischemia,locomotor activity was recorded for 1 h in open field test.Total distance,central distance,central distance ratio,periphery distance,periphery distance ratio,central time and periphery time were used to evaluate the behavior characteristics of locomotor activity in C57BL/6 mice after ischemia.The survival neuron density was detected by Nissl staining in hippocampus,cortex and striatum.Results：Compared with sham group,total distance,central distance and central time increased and periphery time decreased in C57BL/6 mice after GCI （Ps 〈 0.05）.However,minocycline significantly reduced the central distance and central time and increased the periphery time （Ps 〈 0.05）.Neurons were damaged in hippocampus,cortex and striatum after GCI,which manifested by decreased neurons and the most serious damage in hippocampal CA1 region.Minocycline significantly improved the neuron appearance and increased the neuron number in hippocampus and striatum （P 〈 0.001 or P 〈0.05）.Conclusion：Locomotor activity in open field test can objectively evaluate the behavior injury after GCI in mice.Central distance and central time can be used as indexes of quantitative assessment.