Postoperative neurocognitive disorder (PND) is a disease that frequently develops in older patients during the perioperative period. It seriously affects the quality of life of the affected patients. Despite advancements in understanding PND, this disorder’s mechanisms remain unclear, including pathophysiological processes such as central synaptic plasticity and function, neuroinflammation, excitotoxicity, and neurotrophic support. Growing evidence suggests that microenvironmental changes are major factors for PND induction in older individuals. Exosomes are carriers for transporting different bioactive molecules between nerve cells in the microenvironment and maintaining intercellular communication and tissue homeostasis. Studies have shown that exosomes and microRNAs (miRNAs) are involved in various physiological and pathological processes, including neural processes related to PND, such as neurogenesis and cell death, neuroprotection, and neurotrophy. This article reviews the effects of exosomes and miRNAs on the brain microenvironment in PND and has important implications to improve PND diagnosis, as well as to develop targeted therapy of this disorder.

术后神经认知障碍（PND）是围手术期老年患者常见的一种疾病。严重影响受影响患者的生活质量。尽管对 PND 的理解有所进步，但这种疾病的机制仍不清楚，包括病理生理过程，如中枢突触可塑性和功能、神经炎症、兴奋性毒性和神经营养支持。越来越多的证据表明，微环境变化是老年人 PND 诱发的主要因素。外泌体是微环境中神经细胞间转运不同生物活性分子并维持细胞间通讯和组织稳态的载体。研究表明，外泌体和微小RNA（miRNA）参与多种生理和病理过程，包括与 PND 相关的神经过程，如神经发生和细胞死亡、神经保护和神经营养。本文综述了外泌体和 miRNA 对 PND 脑微环境的影响，对改进 PND 诊断以及开发该疾病的靶向治疗具有重要意义。