The Role Of AMPA Receptor In The Injury Of Learning And Memory Induced By Subchronic Aluminum Exposure In Rats

[Objective] To study the role of AMPA receptor in the injury of learning and memory induced by subchronic aluminum exposure in rats.[Methods]1. Male SD rats were randomly divided into4groups:normal saline,0.41mg/kg-bw,0.82mg/kg-bw,1.23mg/kg-bw Al(mal)3groups. Rats were received intraperitoneal injection for8weeks respectively.2. The content of Al in brain was measured by graphite furnace atomic spectrophoto-metry.3. The Morris water maze test was used to examine the learning and memory abilities of rats, the spatial learning was observed by place navigation text in the first four days, and spatial memory was tested by space probe test in the last day.4. HE staining was employed to observe the pathological changes of the hippocampus.5. The gene expression of GluRl, GluR2, GluR3of AMPA receptor were tested by Real-time PCR method.6. The expression of GluRl, GluR2, GluR3of AMPA receptor in hippocampus were detected by immunohistochemisty and western blot method.[Results]1. The content of Al in brain were increased, and compared with the control group, the low, middle and high group was increased (P<0.01).2. Learning and memory capability test shows that compared with the control group, the time which middle and high dose groups finding the platform was significantly prolonged (P<0.05, P<0.05). The time which middle and high dose group remained on the platform was significantly shortened (P<0.05). Compared with the control groups, the frequency of high dose group passing through the platform was significantly shortened (P<0.05).3. HE staining showed that as the aluminum increased, the vertebral cells layer of hip-pocampus were scatteredly arranged, the number of cells was decreased, and vacuolar degeneration was found in the high dose group.4.The gene result shows that compared with control group, the expression of GluRl, GluR2, GluR3were decreased (P<0.01, P<0.01, P<0.05).5. Immunohistochemical result shows that as the higher Al(mal)3exposed, the less immune reactive positive neurons were observed. Wstern blot shows that the expression of AMPA recptor was decreased with the dose of Al(mal)3increasing. Compared with the control group, GluRl protein of middle, high groups were significantly decreased (P<0.01). The GluR2expression of high dose group was decreased (P<0.05). With the dose of Al(mal)3increasing, the expression of GluR3subunit protein was also increased, but no significantly differences among4groups.[Conclusion] Aluminium could cause the content of Al increasing, learning and memory disorder in rats, the vertebral cells layer of hippocampus were decreased, the gene and protein expression of AMPAR were decreased, There might be a hint that the AMPA receptor was related with learning and memory impairment caused by aluminum.