目的 探讨DAPT对脑缺血再灌注损伤小鼠学习记忆能力的影响，以及Notch信号通路的调控作用。 方法 140只健康雄性小鼠随机分为假手术组（sham组）、模型组（I/R组）和DAPT组，每组再分为3d、7d、14d 3个亚组。取材前1 d Y型迷宫检测小鼠学习记忆能力；然后TTC染色测定脑梗死面积；比色法测定脑组织超氧化物歧化酶（SOD）及丙二醛（MDA）含量；光学显微镜下观察海马CA3区形态结构变化；免疫荧光检测Hes1阳性细胞；Western blotting检测Hes5蛋白表达变化并进行定量分析。 结果 与sham组相比，I/R组和DAPT组小鼠学习记忆能力均下降，脑梗死面积增加，SOD活性降低，MDA含量升高（P<0.05）。与I/R组相比，DAPT组小鼠学习记忆能力提高，脑梗死面积减小，SOD活性升高，MDA含量降低（P<0.05）。光学显微镜下，sham组小鼠海马CA3区神经元结构未见异常；I/R组细胞水肿，染色较深，排列疏松，大量神经元缺失，出现核固缩现象；DAPT组细胞数量增加，染色变浅。与sham组相比，I/R组与DAPT组Hes1阳性细胞明显增多，Hes5蛋白表达增加；而DAPT各亚组较I/R各亚组Hes1阳性细胞减少，Hes5蛋白表达降低（P<0.05）。 结论 DAPT对小鼠缺血再灌注损伤有改善作用，其作用机制可能与阻断Notch 信号通路有关。

Objective To study the effect of DAPT on learning and memory abilities and the regulation of Notch signaling pathway in the cerebral ischemia-reperfusion injury mice. Methods A total of 140 health male mice were randomly divided into the sham group, the ischemia-reperfusion (I/R) group, and the DAPT group. Each group was subdivided into the 3 days, 7 days and 14 days subgroups. The learning and memory abilities were detected by Y-maze at one day before execution. Infarct volume was detected by triphenyltetrazolium chloride staining. The colorimetric method was used to detect the superoxide dismutase (SOD) and malondialdehyde (MDA) content. The morphological structures and Hes1 immunopositive cells in the hippocampal CA3 area were observed under a light microscope. Quantitative analysis was performed by cell morphometric technique. The expression of Hes5 protein was detected by Western blotting. Results Compared with the sham group, the learning and memory abilities of both the I/R group and the DAPT group were obviously improved and the SOD activity was significantly increased, but the contents of MDA were decreased (P＜0.05). After DAPT treatment, the SOD activity was obviously decreased, nevertheless the contents of MDA were increased in the DAPT group(P＜0.05).Under a light microscope, the neurons in the hippocampal CA3 area in the sham group were normal, but the neurons of the I/R group were showed cell edema, the dyeing depth, and loose arrangement, and the large number of neurons losed. The number of neurons in DAPT group increased and the staining became shallower. Compared with the sham group, the quantity of Hes1 immunopositive neurons and the expression of Hes5 protein were obviously improved in both the I/R group and the DAPT group. Compared with the I/R group, the expressions of Hes1 and Hes5 in DAPT group were decreased(P＜0.05). Conclusion DAPT can significantly reduce cerebral ischemia-reperfusion injury，which is closely related to the activation of Notch signaling pathway.