Toll样受体4在术后认知功能障碍中作用机制的研究进展

术后认知功能障碍（POCD）是由多种因素引起的麻醉和手术后认知功能减退，持续时间可达数周、数月甚至更长，对高危人群早期筛查和干预能够明显改善围术期POCD患者的转归。Toll样受体4（TLR4）是目前研究最多的免疫炎性模式识别受体，在多种类型的中枢神经细胞中表达并对神经认知发挥调控作用。在POCD发生过程中，TLR4可通过参与炎症反应、调控神经发生、激发氧化应激以及微生物-肠-脑轴等多种途径调控其进展。本文对TLR4的结构和功能和TLR4参与POCD进展的可能作用机制进行综述。

Research progress on the mechanism of Toll-like receptor 4 in postoperative cognitive dysfunction

Postoperative cognitive dysfunction (POCD) refers to the decline of cognitive function after anesthesia and surgery, of which a varity of influencing factors have been widely investigated. POCD results in alterations of memory, learning and behavior that can last for several weeks, months or even longer. Early screening and treatment for high-risk groups can improve the outcome of perioperative POCD patients. Toll-like receptor 4 (TLR4) is one of the most popular receptors recognizing immune inflammatory pattern. In the process of POCD, TLR4 can regulate its progression through various pathways, such as participating in flammatory response, regulating neurogenesis, stimulating oxidative stress, and microbial-gut-brain axis. It is expressed in many types of central nerve cells and plays a vital role in regulating cognitive function. In this review, the structure and function of TLR4, the interaction of signal axis and the possible mechanisms of TLR4 in POCD are elaborated.