Abstract: Background and Objective：Increased blood pressure variability （BPV），which has been considered to cause brain damage，can be induced by sinoaortic denervation （SAD） in rats. This study was designed to test the hypothesis that increased BPV impairs learning and memory in rats with SAD. Methods：SAD was performed in male Sprague-Dawley rats. Passive avoidance trial was used to evaluate learning and memory ability. Results：Compared with shamoperated （Sham） group，there was no significant difference in the latency of passive avoidance in adaption trial. The latency of avoiding darkness in retention trial in SAD group was significantly lower than that in Sham group both 2 and 16 weeks after SAD （P<0.05，P<0.01）. Westernblot assay revealed that all the expression of choline acetyltransferase，vesicular acetylcholine transporter and α7 nicotinic acetylcholine receptor decreaed in both cerebral cortex （P<0.05） and hippocampus （P<0.05） 16 weeks after SAD （P<0.05），while only level of α7 nicotinic acetylcholine receptor was reduced in hippocampus 2 weeks after SAD （P<0.05）. Conclusion： Increasd BPV reduces memory ability in SAD rats，potentially through cholinergic pathway.

Key words: blood pressure variability, sinoaortic denervation, memory, cholinergic, &alpha, 7nicotinic acetylcholine receptor