Effects of excessive intake of trace elements on senile neuropathy and the development of a method for biological monitoring of trace elements

微量元素如锌（Zn）、铁（Fe）、铜（Cu）和锰（Mn）是必需元素，但已知过量的这些元素会引起许多神经退行性疾病。我们的研究表明，一些植物或动物来源的补充剂含有高浓度的Zn，Fe，Cu和Mn。本研究采用动物行为学、避暗回避、Y迷宫和新物体识别等实验方法，观察了慢性锰、锌、铜暴露对成年雄性和雌性大鼠行为学、避暗回避、Y迷宫和新物体识别的影响。这些行为测试表明，慢性暴露于锰抑制长期记忆和慢性暴露于锌抑制物体识别记忆的可能性。

Trace elements, such as zinc (Zn), iron (Fe), cupper (Cu) and manganese (Mn) are essential elements but excess amounts of these elements are known to cause many neurodegenerative diseases. Our studies showed that some supplements of botanical or animal origin contained high concentrations of Zn, Fe, Cu and Mn. Our questionnaire survey suggested that the risk of excessive intake of the trace elements is caused by taking food plus botanical or animal origin supplements.We investigated the effects of chronic exposure to Mn, Zn and Cu on animal behavior tests, a step-through passive avoidance task, a Y-maze test and a novel object recognition test, in male or female adult rats. These behavioral tests indicated the possibilities that chronic exposure to Mn inhibited long-term memory and chronic exposure to Zn inhibited object recognition memory.