title: Altered functional brain networks in amnestic mild cognitive impairment: a resting-state fMRI study.
abstract: Amnestic mild cognitive impairment MCI (aMCI) has a high progression to Alzheimer's disease (AD). Recently, resting-state functional MRI (RS-fMRI) has been increasingly utilized in studying the pathogenesis of aMCI, especially in resting-state networks (RSNs). In the current study, we aimed to explore abnormal RSNs related to memory deficits in aMCI patients compared to the aged-matched healthy control group using RS-fMRI techniques. Firstly, we used ALFF (amplitude of low-frequency fluctuation) method to define the regions of interest (ROIs) which exhibited significant changes in aMCI compared with the control group. Then, we divided these ROIs into different networks in line with prior studies. The aim of this study is to explore the functional connectivity between these ROIs within networks and also to investigate the connectivity between networks. Comparing aMCI to the control group, our results showed that 1) the hippocampus (HIPP) had decreased FC with the medial prefrontal cortex (mPFC) and inferior parietal lobe (IPL), and the mPFC showed increased connectivity to IPL in the default mode network; 2) the thalamus showed decreased FC with the putamen and HIPP, and the HIPP showed increased connectivity to the putamen in the limbic system; 3) the supplementary motor area had decreased FC with the middle temporal gyrus and increased FC with the superior parietal lobe in the sensorimotor network; 4) increased connectivity between the lingual gyrus and middle occipital gyrus in the visual network; and 5) the DMN has reduced inter-network connectivities with the SMN and VN. These findings indicated that functional brain networks involved in cognition such as episodic memory, sensorimotor and visual cognition in aMCI were altered, and provided a new sight in understanding the important subtype of aMCI.
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China.
authors.forename: Suping
authors.initials: S
authors.lastname: Cai
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Chong
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Peng
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China.
authors.forename: Wenyue
authors.initials: W
authors.lastname: Shen
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China.
authors.forename: Karen M
authors.initials: KM
authors.lastname: von Deneen
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710126, China. huangly@mail.xidian.edu.cn.
authors.forename: Liyu
authors.initials: L
authors.lastname: Huang
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology; D009929:Organ Size; D012146:Rest
keywords: Amnestic mild cognitive impairment; Default mode network; Functional connectivity; Limbic system; Sensorimotor network; Visual network