Changes of learn memory and contents of brain monoamine neurotransmitter in rats with aluminum exposure

Objective To observe the effect of aluminum on the learn memory and contents of monoamine neurotransmitter in rats brain and to provide evidence on the mechanism of neurotoxicity. Methods 144 Wistar rats were divided into three experimental and one control group, experimental groups were intraperitoneally injected with aluminum chloride in 5.0, 15.0 and 25.0 mg/kg respectively and control group intraperitoneally injected with N.S for several weeks. Step-down test was performed and then killed, the contents of monoamine neurotransmitter in rat brain was measured with Fluorescene Spectrophotometer. Results Aluminum could decrease active avoidance response and retard passive avoidance time significantly (P 0.01); DA and NE levels were less than those of control group significantly (P 0.01); 5-HT and 5-HIAA levels in all dose groups were less than those in control group significantly (P 0.01) except 5-HT levels in cerebrum and 5-HIAA levels in hippocampus levels at dose of 5.0 mg/kg during the 4th and the 8th weeks.Conclusion It suggested that aluminum could have influence on learn memory and could decrease monoamine neurotransmitter levels in different brain regions. It might be one of the mechanisms of aluminum neurotoxicity.