衰老和神经系统疾病导致的认知功能下降严重影响老年人的日常生活行为和生活质量，因此寻找有效的干预措施以改善老年人的认知功能和提高生活质量已日益受到重视。运动可以降低阿尔茨海默病和抑郁症的发病风险，改善记忆和认知功能，促进大脑健康，但是目前尚不清楚其中的分子机制。鸢尾素（irisin）是一种肌肉因子，由膜结合蛋白前体骨骼肌Ⅲ型纤连蛋白组件包含蛋白5（fibronectin type Ⅲ domain-containing protein 5，FNDC5）剪切加工而成，而运动是促进鸢尾素合成和分泌的主要因素。鸢尾素可以促进神经干细胞分化，增加神经可塑性，改善记忆和认知功能。最近的研究表明，运动可以直接促进神经组织表达FNDC5，通过过氧化物酶体增殖物激活受体γ辅激活因子1α（peroxisome proliferator-activated receptor-γ coactivator-1α，PGC-1α）-FNDC5-脑源性神经营养因子（brain-derived neurotrophic factor，BDNF）信号通路影响大脑的微观结构和功能。运动还可以刺激肌肉等组织合成和分泌大量的鸢尾素，并促进大脑分泌BDNF。鉴于鸢尾素在神经系统调节中的重要作用及其与运动的密切关联，本文对鸢尾素在调控运动促进大脑功能中的作用机制的研究进展进行综述。

The decline of cognitive function caused by aging and neurological diseases seriously decreases the ability of daily life and the quality of life in old people. Therefore, it has been paid more and more attention to find effective interventions to improve the cognitive function and quality of life of the old people. Exercise can reduce the risks of Alzheimer disease (AD) and depression, improve the memory and cognitive function, and keep brain healthy, but the underlying molecular mechanism remains unclear. Irisin is a muscle cytokine, which is a cleaved version of fibronectin type Ⅲ domain-containing protein 5 (FNDC5), and the exercise is the main factor to promote the synthesis and secretion of irisin. Irisin can promote the differentiation of neural stem cells, increase the neuroplasticity, and improve the memory and cognitive function. Recent studies have shown that exercise can directly promote the expression of FNDC5 in nerve tissue, and influence the microstructure and function of the brain by peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α)-FNDC5-brain-derived neurotrophic factor (BDNF) pathway. Exercise can also stimulate the muscles and other tissues to synthesize and secrete a large amount of irisin, and promote the brain to secrete BDNF. In view of the important role of irisin in the regulation of nervous system and its close relationship with exercise, this paper reviews the research progress in the mechanism of irisin regulating exercise to promote the brain function.