脑发育不同阶段甲醛暴露对大鼠学习记忆能力及海马CA3区CaMKⅡ表达的影响  

Effects of inhaled formaldehyde on learning and memory and expression of CaMKⅡ in hippocampus of Wistar rats of different ages

作　　者：廖双[1] 蒋莉[1] 张晓萍[1] 

机构地区：[1]重庆医科大学附属儿童医院神经内科,重庆400014

出　　处：《重庆医科大学学报》2010年第3期342-345,共4页Journal of Chongqing Medical University

摘　　要：目的:研究低浓度甲醛吸入对脑发育不同阶段大鼠空间学习记忆能力、生长发育及海马CA3区CaMKⅡ表达的影响。方法:选择生后3d、14d、60d(相当于新生儿期、幼年期、成年期)Wistar大鼠,每年龄段随机分为对照组和染毒组各8只,采用吸入方式染毒(甲醛浓度为0.5mg/m3),2h/d,连续28d;监测大鼠体重,用Morris水迷宫检测其空间学习记忆能力,免疫组织化学方法检测海马CA3区CaMKⅡ表达。结果:所有染毒组大鼠较同龄对照组均出现体重增长落后(P<0.05);新生鼠染毒组和幼年鼠染毒组在Morris水迷宫中定位航行实验逃避潜伏期比同龄对照组明显延长(P<0.05);空间探索试验穿越平台次数也明显少于同龄对照组(P<0.05);免疫组织化学检测海马CA3区CaMKⅡ表达较同龄对照组下降(P<0.05);而成年组除染毒组体重增长落后外,水迷宫逃避潜伏期、穿越平台次数及海马CA3区CaMKⅡ表达两组均无显著性差异(P>0.05)。结论:甲醛吸入染毒可能影响Wistar大鼠学习记忆能力,脑发育早期(新生儿期和婴幼儿期)对甲醛的神经毒性更为敏感;海马CA3区CaMKⅡ表达下降可能是甲醛影响大鼠学习记忆的机制之一。Objective：To investigate the effects of inhaled low level formaldehyde on learning and memory,the body weight,and the expression of CaMKⅡ in hippocampus of Wistar rats of different ages.Methods：48 Wistar rats including 16 neonatal rats（P3）,16 childhood rats（P14） and 16 adult rats（P60） were divided into control groups and formaldehyde exposure groups randomly according to their age.During 28 consecutive days,the experimental groups were exposed to the gaseous formaldehyde（0.5mg/m3） for 2 h/d.The Morris water maze test was conducted to investigate the spatial learning and memory of the rats.The expressions of CaMKⅡ were assayed by immunohistochemical techniques.Results：The body weight of all the experimental groups were less than that of control groups（P0.05）.In neonatal and childhood rats groups,the escape latency in experimental groups were significantly longer than that of control groups（P0.05）,while the frequency of stepping over the platform location were significantly less than that of control groups（P0.05）,and the expression of CaMKⅡ in hippocampus in experimental groups showed a significant decrease compared with control groups（P0.05）.But in adult groups there were no significant difference between experimental groups and the control groups（P0.05）,except with the body weight.Conclusion：Inhaled formaldehyde has a negative effect on learning and memory of Wistar rats;the developing brain appears far more vulnerable than the mature brain.Changes of CaMKⅡ in hippocampus may be one of the mechanisms of the effects on learning and memory.

关 键 词：甲醛 学习记忆 钙调蛋白依赖性蛋白激酶 发育期 

分 类 号：R126.8[医药卫生—环境卫生学]