褪黑素对侧脑室注射氯化铝致小鼠学习记忆障碍的改善作用及其机制

EFFECT OF MELATONIN ON LEARNING AND MEMORY IMPAIRMENT INDUCED BY ALUMINUM CHLORIDE AND ITS MECHANISM

目的 探讨褪黑素 (MLT)对氯化铝 (AlCl3 )致小鼠拟阿尔茨海默病学习记忆功能障碍的改善作用及其机制。方法 避暗法测试各组小鼠被动回避能力 ,水迷宫法测空间学习记忆能力及测定大脑皮层及海马组织超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GSH Px)活性及丙二醛 (MDA)含量。结果 MLT可明显改善AlCl3 致小鼠被动回避记忆能力、空间学习记忆能力的下降 ;对AlCl3 诱发的小鼠大脑皮层及海马组织总SOD ,CuZn SOD和GSH Px活性下降及MDA含量增加均有显著的对抗作用。结论 MLT对AlCl3 致小鼠学习记忆功能障碍有显著改善作用 。

AIM To investigate the effect of melatonin on learning and memory impairment in mice induced by aluminum chloride and its possible mechanism. METHODS Mice were treated with intracerebroventricular (icv) injection of 2 μL 5% alumi num chloride solution, once a day for 5 d. At the same time, the mice were given intraperitoneally melatonin 0 6, 3 and 15 mg·kg -1 , once a day for 1 4 d. The passive avoidance of the mice was assessed by step through test on day 15 after the last icv injection, and then the place navigation and spatial prob e ability by Morris water maze were tested. After the spatial probe test, the ac tivities of total superoxide dismutase (T SOD), CuZn superoxide dismutase (CuZn SOD), glutathione peroxidase (GSH Px) and the content of malondialdehyde (MDA ) in the cerebral cortex and hippocampus of mice brain were determined. RESULTS Melatonin ameliorated significantly the impairment of passive avoidance memory, the place navigation and spatial probe ability of mice induced by aluminum chlor ide. Melatonin was found to prevent significantly the decline of T SOD, CuZn S OD and GSH Px activities, the increase of MDA content in the cortex and hippoca mpus of mouse brain induced by aluminum chloride. CONCLUSION The results suggest that melatonin improves significantly the learning and m emory impairment in mice induced by aluminum chloride, and this effect may be at tributed to its antioxidation.