EFFECTS OF ZINC ON LEARNING AND MEMORY IN D-GALACTOSE-INDUCED AGING MICE / 营养学报

ABSTRACT

Objective: To study the effects of zinc-deficiency(ZD)and zinc-supplement(ZS)on learning and memory in aging mice. Methods: Seventy 3-month-old male mice were divided randomly into 5 groupsnormal young , aging model , aging+ZD, aging+pair-fed , aging+ZS . The aging model was established with D-galactose (100 mg/kg bw) by nape subcutaneous injection, while the young control group was injected with normal saline in the same way, which lasted 30 days. Aging+ZD and aging+ZS group were fed with ZD feed(zinc 1.61 mg/kg), others with normal feed(zinc 50 mg/kg). ZS feed(zinc 100 mg/kg)was given to aging+ZS for last 2 weeks. During the last week, the behavior tests were carried on. Finally the mice were all killed and samples were collected immediately for detection of indices . Results:Compared with the aging model group, ZD made serum zinc decrease significantly, the locomotor activity reduced and the ability of learning and memory weakened. Comet assay also showed that ZD induced DNA damage of cerebrum cells more serious in aging mice than the control. The ratio of tail length/comet cell length in Group ZD also increased significantly. However, moderate ZS could turn those indices better significantly. Conclusion: Zinc can ameliorate the learning and memory function of aging significantly. By reducing the function of DNA repair, ZD can act on learning and memory, while moderate ZS seems to be beneficial.