照明不足对生长期小鼠学习记忆的影响

Effects of insufficient illumination on the development, learning and memory of growing mice

目的：研究不同光照强度对生长期小鼠学习记忆的影响，进一步揭示照明不足对动物的危害。方法40只21日龄小鼠随机分为对照组、1 Lx光照组、10 Lx光照组以及50 Lx光照组，每组10只。各组小鼠每天不同强度光照持续照射8 h，连续照射3周后进行Morris水迷宫试验，最后将小鼠迅速断头取脑，冰台分离海马，检测乙酰胆碱酯酶（AchE）活性。结果与对照组相比，1 Lx光照组和10 Lx光照组AchE活性明显增高（P＜0．05），50 Lx光照组AchE活性无统计学意义。1 Lx 光照组 Morris 水迷宫试验穿越平台次数明显少于对照组（ P＜0．05），其余3组穿越平台次数的差异无统计学意义。各光照组与对照组相比，Morris水迷宫试验逃避潜伏期的差异无统计学意义。结论1 Lx光照使小鼠海马区AchE活性增高、学习记忆受损。

Objective To observe the effect of illumination at various light intensities on the learning and memory of growing mice, in order to reveal the damages of insufficient illumination to animals .Methods A total of 40 mice aged 21 days were randomly divided into four groups： a control group, a 1 Lx light group, a 10 Lx light group and a 50 Lx light group （n=10）.After continuously illuminated at different light intensities for 8 hours per day for 3 weeks, these animals were examined using the Morris′water maze test .The brains were removed to separate the hippocampus and then the activi-ty of acetylcholinesterase （ AchE） was measured .Results Compared with the control , the 1 Lx light group and the 10 Lx light group produced significantly enhanced activities of AchE （P〈0.05）.In contrast, no statistical difference was found in AchE activity between the 50 Lx light group and the control group .Mice in the 1 Lx light group less frequently reached the platform than the controls in the Morris′water maze test （P〈0.05）.There were no significant difference between the three light-exposure groups and the control group as to the mean latency in the Morris′water maze test .Conclusion Ex-posure of 1Lx illumination can enhance the activity of AchE in the hippocampus but impair learning and memory in mice .