Objective    To explore the role of nicotine pretreatment on Alzheimer disease (AD).     Methods    Totally 26 SD rats orally took 5 μg/ml nicotine in 2% sugar solution daily

and then 7 d later

they (nicotine AD group) and other 26 rats (AD group) received the injection of amyloid peptideβ

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into their hippocampus to establish AD rat model. Another 8 rats served as normal control. Functions of learning and memory were evaluated by Morris test.     Results    During the place navigation test

the latency of the nicotine AD group was  decreased compared with the AD group

and the percentages of swimming time and swimming distance at the target quadrant were higher than the AD group.     Conclusion    Nicotine prevents the dysfunction of learning and memory induced by Aβ

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. The

mechanism may be related with neurotransmitter release promoted by nicotine.