铜对大鼠学习记忆和海马区p-ERK表达的影响

目的观察铜负荷饮食对大鼠空间学习记忆行为和海马区神经元p-ERK1/2表达的影响。方法 40只雄性大鼠适应性喂养1周后,随机分为模型组和空白对照组各20只,模型组予含硫酸铜1 g/kg的粉状饲料和含量为0.185%硫酸铜的去离子水喂养,正常对照组喂食普通饲料,8周后采用Morris水迷宫实验测试大鼠学习记忆能力,采用原子吸收法检测肝、脑组织Cu元素含量,免疫组化方法检测海马区细胞外信号调节激酶磷酸化p-ERK1/2阳性细胞表达。结果 Morris水迷宫实验中模型组大鼠在定位航行试验中平均逃避潜伏期较正常对照组显著延长,空间探索试验中穿越平台次数较正常组明显减少(P<0.01),与正常对照组比较,模型组大鼠肝、脑组织Cu元素含量明显增加(P均<0.01),海马组织内p-ERK1/2阳性细胞数明显减少(P<0.01)。结论铜过量负荷可能通过ERK信号通路损伤海马神经元引起大鼠学习记忆功能障碍。

Effects of copper on learning and memory and p-ERK expression in hippocampus of rats

Objective It is to observe the effects of copper-overloaded diet on learning and memory and P-ERK expression in hippocampus of rats.Methods After 1 week's acclimation 40 male SD rats were randomly divided into 2 groups,control group and model group.The control group was given ordinary forage and water,the model group was given forage containing 1 g/kg copper sultate and water containing 0.185% copper sulfate.After 8 weeks feeding,Morris water maze was used to evaluate the learning and memory ability of the rats.Cu and Zn contents in liver and brain tissue were measured by atomic absorption spectrometer.Immunohistochemistry was used to detect p-ERK1/2 expression in in the hippocampus.Results In Morris water maze test,the mean escape latent period of the rats in model group was obviously longer and the times of traversing flat roof was obviously less than that of the rats in normal group(P<0.01).Compared with that of normal group,the contents of Cu and Zn in liver and brain tissue were increased in model group(P<0.01).the number of apoptotic p-ERK1/2 cells in hippocampus significantly decreased(P<0.01).Conclusion Copper-overloaded diet can cause learning and memory dysfunction of rats by damaging hippocampus neurons by affecting the activation of ERK signaling pathway.