饲料缺锌对幼鼠脑发育和学习记忆的影响

Effects of Zinc Deficiency in Fodder on Brian Development, Learning and Memory in Rats

从哺乳期开始建立缺锌幼鼠模型，采用电镜观察、神经生化和神经电生理等方法，观察饲料缺锌对幼鼠脑发育和学习记忆的影响并探讨其机理。结果如下：①缺锌组脑重、海马重及血清、海马锌含量均明显低于正常组。②缺锌组ＬＴＰ（ｌｏｎｇ－ｔｅｒｍｐｏｔｅｎｔｉａｔｉｏｎ）诱发率为０，其主动回避反应习得率明显低于ＬＴＰ诱发率为１００％的正常组。③大脑皮层及海马组织兴奋性和抑制性氨基酸以及谷氨酸、γ－氨基丁酸含量、海马一氧化氮含量缺锌组均明显高于正常组，而海马生长抑素含量及锥体细胞核ＤＮＡ含量则缺锌组明显低于正常组。④海马锥体细胞突触小泡较正常组减少。提示膳食缺锌明显影响幼鼠脑发育及功能。

Zinc deficiency (ZD) model was established in young rats starting from their lactation period. Effects of ZD in fodder on brian development and learning and memory were observed with electron microscopy and neurobiochemical and electroneurophysiological methods, and its mechanism was studied. Results showed that ① brain weight, hippocampal weight, and serum and hippocampal zinc concentrations were significantly lower in ZD group than those in controls; ② proportion of induced long term potentiation (LTP) was zero in ZD group and proportion of active avoidance response decreased profoundly in ZD group, significantly lower than that in normal controls whose LTP proportion was 100%; ③ concentrations of excitatory and inhibitory amino acids, glutamic acid, γ aminobutyric acid in cerebral cortex and hippocampus and nitrous oxide in hippocampus were significantly higher in ZD group than those in normal one, and content of somatostatin in hippocampus and DNA in pyramidocytes were significantly lower in ZD group than those in normal one; and ④ number of synaptic vesicles in pyramidocytes of hippocampus decreased obviously in ZD group. It suggests that brain development and function are obviously affected by fodder zinc deficiency in rats.