高锌饮食对大鼠学习记忆的影响

Effect of high zinc content diets on learning and memory in rats

本实验通过给动物喂以添加不同剂量锌的饲料（每公斤干饲料中添加２００、４００、８００、１２００ｍｇ硫酸锌，即Ｚ１、Ｚ２、Ｚ３、Ｚ４组），应用Ｙ－迷宫，步入试验及跳台试验等方法来探讨锌在学习记忆中的作用。结果表明：各组动物体重及旷场行为无显著差异；Ｚ１组在Ｙ－迷宫中达到学会标准所用的资数明显减少；Ｚ４组在步入试验中，潜伏期明显缩短，在跳台试验中，记忆保持率则有下降的趋势；实验组血锌较对照组有不同程度的提高；海马锌的含量除Ｚ４组外，其余三组均较对照组有显著升高；本实验提示；添加低剂量锌对学习记忆有促进作用，而过高剂量锌对学习记忆有损害作用。

Using Y-maze, step-through and step-down methods, the role of zinc in learning and memory was studied in rats fed with different additional zinc content food(Z1 200, Z2 400, Z3 800, Z4 1200mg ZnSO4/Kg) for 12 weeks. The results were as follows:there were no significant differences in body weight gaining and open field behaviour among different groups, but the tests of learning and memory showed some changes: the group Z1 took much less time to acquire the task in Y-maze(p<0.05); in group Z4,the step-through was signif,cantly shortened (P<0.05) and the memory keeping rate in step-down showed a declining tendency(P<0.1); the blood zinc content increased significantly in all four groups compared with the control; the hippocampal zinc content showed a significant increase in group Z1, Z2, Z3, but not in group Z4. This study showed that a proper dose of additional zinc may have a faciliated effect,whereas a high dose of additional zinc may have a noxious effect on learning and memory in rats.