术后认知功能障碍（POCD）是指麻醉和手术后出现的记忆能力下降等认知功能改变，可降低生活质量，增加术后死亡率。临床证据表明局麻下手术仍然可以发生POCD。手术本身造成的中枢炎症反应与动物术后学习和记忆能力下降相关，但是不能解释类似的炎症反应仅破坏老年个体的学习和记忆能力，而对成年个体没有影响。胆碱能神经系统随年龄退化，可以造成中枢对抗各种损伤的能力下降。我们的研究证明胆碱酯酶抑制剂能够预防异氟醚造成的老年动物学习和记忆能力下降，因此我们认为中枢胆碱能神经系统的退化程度是造成不同月龄动物术后学习和记忆能力发生不同变化的主要原因。本研究中分别选择阑尾切除术后学习和记忆能力没有变化的低月龄小鼠和明显降低的高月龄小鼠进行中枢胆碱能神经系统干预，通过术后学习和记忆能力变化来确定假说的正确性。同时研究其机制与脑源性神经营养因子的关系。本课题可为临床上应用胆碱酯酶抑制剂防治POCD提供理论依据。

Postoperative cognitive dysfunction(POCD) is a kind of learning and memory impairment after anesthesia and surgery. It decrease the quality of life and even increase the mortality. Clinical evidences showed that POCD occured after sugery even with local anesthesia. Cerebral inflammation induced by surgery is related to the impairment of the learning and memory after surgery. However, it can not explain why the samilar cerebral inflammation only impair the learning and memory ability of aged animals but not the adult. Cerebral cholinergic system, which play neuroprotective or compensatory role against injury, degradate significantly with aging. Our pervious study demonstrated that Donepezil an acetylcholinesterase inhibitor prevent the damage of learing and memory induced by isoflurane exposure.Token together, we hypothesized that the different degrees of cerebral cholinergic degradation was the main reason of the different response of different aged animals to surgery. In order to confirm the hypothesis, in present study we will observe the different effects of appendectomy on the learning and memory ability of different aged animals. Then we will interfere the cerebral cholinergic system and investigate the changes of learning and memory ability in different aged animals, and finally verify the hypothesis. At the same time we also test the roles of brain-derived neurotrophic factor in it. Present study will supply the basic theory for applying cholinesterase inhibitors on the therapy of POCD.