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.
Krüppel-like factor 4 (KLF4) is a member of the sample Kruppel transcription factor protein family, is an evolutionary conservative contain zinc finger transcription factors, involved in regulating many cellular processes, such as cell growth, proliferation, differentiation and invasion, KLF4 expression in a variety of tissues and cells in the body, has widely in many physiological and pathological conditions. Many studies have shown that KLF4 is involved in neurobiological processes such as neuroinflammation, oxidative stress, apoptosis and axon regeneration, and is closely related to a variety of nervous system diseases such as epilepsy, stroke, and Alzheimer’s disease. Now KLF4 in its role in the development of nervous system diseases were reviewed, help to understand the pathogenesis of the disease and clinical treatment for diseases of the nervous system to provide potential targets.