自主运动后BALB/c和C57BL/6小鼠学习记忆行为学指标的分析比较

Learning and memory abilities between BALB/c and C57BL/6 mice after voluntary movement

背景:BALB/c和C57BL/6小鼠是实验室常用的两种近交品系,但是自主运动后如何科学、合理选择行为学实验方法和指标,评价小鼠的学习记忆能力目前尚无相关报道。目的:分析比较自主运动后BALB/c和C57BL/6小鼠与学习记忆相关的行为学指标差异,为探讨运动对学习记忆能力的影响,并选择合理的行为学指标提供参考。方法:将2.5月龄BALB/c和C57BL/6小鼠分别随机分为对照组和跑轮运动组,应用Vital View软件记录小鼠自主跑轮运动。跑轮运动4周后,通过DCX免疫荧光染色检测海马新生神经元;新异臂探索实验、新物体识别实验和水迷宫实验分析比较小鼠空间学习记忆和探索能力。结果与结论:1BALB/c小鼠平均每天运动量约是C57BL/6小鼠的2.56倍(P<0.001)。2跑轮运动后两种品系小鼠海马DCX阳性细胞数较对照组增多。3跑轮运动后两种品系小鼠探索新异臂和新物体的次数、围绕新异臂和新物体探索的时间和距离均较对照组增高(P<0.001),其中BALB/c跑轮组的探索能力优于C57BL/6跑轮组(P<0.05)。4Morris水迷宫实验结果表明,C57BL/6跑轮组寻找平台的时间缩短,小鼠到达平台次数、在目标象限探寻的时间和距离均较对照组延长(P<0.05);但是,BALB/c跑轮组和对照组间水迷宫实验各项指标无统计学差异。综上所述,运动能促进BALB/c和C57BL/6小鼠海马神经发生;新异臂探索和新物体识别实验能够用于检测运动后两种小鼠的学习记忆能力,其中BALB/c的学习记忆能力优于C57BL/6小鼠,但运动后BALB/c小鼠不适合应用水迷宫实验检测其空间学习记忆能力的变化。

BACKGROUND： BALB/c and C57BL/6 mice are two inbred strains, but after voluntary movement, there is no report on how to scientifical y reasonably select behavioral experiment methods and indicators and to evaluate the learning and memory abilities of mice. OBJECTIVE： To analyze and compare the behavioral indicators between BALB/c and C57BL/6 mice fol owing voluntary wheel running, to explore the effect of exercise on learning and memory, and to provide a reference for selecting reasonable behavioral indicators. METHODS： 2.5-month-old BALB/c and C57BL/6 mice were randomly divided into control and voluntary wheel running groups. Independent running wheel movement of mice was recorded with VitalView system. 4 weeks later, newborn neurons were labeled via DCX immunofluorescence. Spatial learning, memory and exploration abilities were compared through new arm test, new object recognition test and Morris water maze test. RESULTS AND CONCLUSION： （1） The mean spontaneous activity of BALB/c mice daily was 2.56 fold of that of C57BL/6 mice during wheel running （P 〈 0.001）. （2） Hippocampal DCX-positive cel s in exercised BALB/c and C57BL/6 mice were more than those in control group. （3） Meantime, exhibited by higher frequencies to explore new arm or object, and longer time and distance of moving around them, the learning and exploring capability was improved after exercising （P 〈 0.001）, especial y in BALB/c mice. （4） Wheel running C57BL/6 mice exhibited progressed spatial learning and memory abilities compared with control mice in Morris water maze test, characterized by decreased latency to target, elevated target crossings and longer time or distance in quadrant zone （P 〈 0.05）. However, there was no significant difference between wheel running and control BALB/c mice. Taken these data together, voluntary wheel running contributed to hippocampal neurogenesis of BALB/c and C57BL/6 mice, accompanied by the change of learning and memory capability, which could be detected properly via both new arm test and new object recognition test, but for Morris water maze test, C57BL/6 mice might be superior to BALB/c mice.