Preconditioning with sevoflurane ameliorates spatial learning and memory deficit after focal cerebral ischemia–reperfusion in rats

•Early animal study showed the occurrence of hippocampal neuronal damage following middle cerebral artery occlusion (MCAO) in rats.•Spatial learning and memory in rats and humans are largely dependent on the hippocampal formation.•We examine preconditioning with sevoflurane offers a protective effect on the ChAT positive cells in CA1 region.•We find that preconditioning with sevoflurane ameliorates spatial learning and memory ability in rats.

Previous studies have demonstrated that sevoflurane could attenuate cerebral neuron necrosis and apoptosis in ischemia–reperfusion models in rats. The aim of our study was to investigate the effect of preconditioning with sevoflurane on spatial learning and memory ability after focal cerebral ischemia–reperfusion injury in rats and its potential mechanisms. Focal cerebral ischemia was performed via 1 h of middle cerebral artery occlusion (MCAO) followed by reperfusion. Before ischemia, rats were subjected to preconditioning with inhalation of 2.4% sevoflurane for 1 h. The spatial learning and memory ability of rats was measured by the Morris water maze. The activity of choline acetyltransferase (ChAT) in hippocampus CA1 region was observed by immunohistochemistry method. We found MCAO elicited a significant decrease of the ability of spatial learning and memory in contrast to the sham surgery controls. However, preconditioning with sevoflurane resulted in significantly ameliorates spatial learning and memory deficit induced by MCAO. Furthermore, the number of ChAT positive cells in hippocampus CA1 region in sevoflurane preconditioning group was striking more than that of ischemia–reperfusion group. All results suggested that preconditioning with 2.4% sevoflurane could ameliorate the ability of spatial learning and memory after focal cerebral ischemia–reperfusion in rats via protecting the cholinergic neurons in hippocampal CA1 region.