饲料锌对幼鼠海马发育和学习记忆的影响

从哺乳期开始建立缺锌（ＺＤ）高锌（ＺＨ）和对照（ＡＬ）幼鼠模型研究饲料锌含量对幼鼠海马发育和学习记忆的影响。结果、（１）ＺＤ、ＺＨ组幼鼠体重增长值、饲料效价均低于ＡＬ组（Ｐ＜０．０１）；（２）血清锌和海马锌含量ＺＤ组明显低于而ＺＨ组明显高于ＡＬ组；（３）海马锥体细胞ＤＮＡ含量ＺＤ组明显低于ＡＬ组，ＺＨ组与ＡＬ组无差异；（４）兴奋性和抑制性基氨酸总量ＺＤ、ＺＨ组均高于ＡＬ组，以谷氨酸和γ氨基丁酸差异最显著；（５）ＺＤ、ＺＨ组主动回避反应习得率均明显低于ＡＬ组；（６）ＺＤ、ＺＨ组海马长时程增强诱发率为０，ＡＬ组为１００％；（７）海马神经元突触小泡ＺＤ组明显减少，而ＺＨ组则突触小泡破裂，海马神经元、胶质细胞均有不同程度变性坏死，上述结果提示：从哺乳期开始摄入缺锌、高锌饲料均可影响幼鼠海马发育和学习记忆。

THE INFLUENCE OF DIETARY ZINC LEVELS ON THE HIPPOCAMPAL DEVELOPMENT AND LEARNING MEMORY IN YOUNG RATS

New born rats were divided into three groupsZn deficiency(ZD),high Zn (ZH), ad libitum(AL) to study the effect of dietary Zn level on hippocampal development and learning memory. The results showed:(1)Both the increase of body weight and feed efficiency in ZD and ZH groups were remarkably lower than that of AL group(<0.01).(2)Compared with AL group, Zn levels of serum and hippocampus in ZD and ZH groups were lower and higher respectively.(3)DNA content of hippocampal pyramidal neuron in ZD group was significantly lower than than of AL group, and no difference was seen between ZH and AL groups. (4)The amounts of excitatoty amino acids and inhibitory amino acids in ZD and ZH groups were remarkably and inhibitory amino acids in ZD and ZH groups were remarkably higher than that of AL group, especially the contents of glutamic acid and GABA were the highest.(5)The active advoidance response rates of ZD and ZH groups were lower than that of AL group. (6)The induced rates of longterm potentiation of ZD and ZH groups were zero, but 100% in AL group after stimulating. (7)Numbers of synaptic vesicles of hippocampal pyramidal neuron decreased in ZD group, while in ZH group ruptures of synaptic vesicles, degeneration of hippocampal neurons and glial cells could be found in different degrees.All of tlie results suggested that both Zn deficiency and high Zn intake might have effects on hippocampal development and learning memory in young rats.