Normal brain aging and a serious of neurodegenerative diseases may lead to decline in memory, attention and executive ability and poorer quality of life. The mechanism of the decline is not clear now and is still a hot issue in the fields of neuroscience and medicine. A large number of researches showed that resting state functional brain networks based functional magnetic resonance imaging (fMRI) are sensitive and susceptive to the change of cognitive function. In this paper, the researches of brain functional connectivity based on resting fMRI in recent years were compared, and the results of subjects with different levels of cognitive decline including normal brain aging, mild cognitive impairment (MCI) and Alzheimer's disease (AD) were reviewed. And the changes of brain functional networks under three different levels of cognitive decline are introduced in this paper, which will provide the basis for the detection of normal brain aging and clinical diseases.
正常脑老化和神经退行性疾病等都会引起记忆力、注意能力等认知功能不同程度的衰退，严重影响日常生活。其发生发展的神经机制目前仍不明确，依然是神经科学和医学领域的一个热点问题。大量研究成果表明，基于磁共振的静息态网络（RSNs）对认知功能的改变具有较高的敏感度和特异性。本文调查近几年静息态功能磁共振成像（fMRI）脑功能连接网络对正常脑老化（aging brain）、轻度认知障碍（MCI）和阿尔兹海默病（AD）等不同认知衰退水平受试者的研究，从分析方法、研究结果以及发展趋势等进行了综述，较全面地介绍了在三种不同水平认知衰退条件下脑功能网络的改变，将为正常脑老化和临床疾病的检测提供依据。.
Keywords: Alzheimer’s disease; aging brain; functional connectivity; mild cognitive impairment.