title: Altered effective connectivity patterns of the default mode network in Alzheimer's disease: an fMRI study.
abstract: The aim of this work is to investigate the differences of effective connectivity of the default mode network (DMN) in Alzheimer's disease (AD) patients and normal controls (NC). The technique of independent component analysis (ICA) was applied to identify DMN components and multivariate Granger causality analysis (mGCA) was used to explore an effective connectivity pattern. We found that: (i) connections in AD were decreased than those in NC, in terms of intensity and quantity. Posterior cingulated cortex (PCC) exhibited significant activity in NC as it connected with most of the other regions within the DMN. Besides, the PCC was the convergence center which only received interactions from other regions; (ii) right inferior temporal cortex (rITC) in the NC exhibited stronger interactions with other regions within the DMN compared with AD patients; and (iii) interactions between medial prefrontal cortex (MPFC) and bilateral inferior parietal cortex (IPC) in the NC were weaker than those in AD patients. These findings may implicate a brain dysfunction in AD patients and reveal more pathophysiological characteristics of AD.
authors.affiliation: School of Life Science and Technology, Xidian University, Xi-an, Shaanxi 710071, China.
authors.forename: Yufang
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: School of Life Science and Technology, Xidian University, Xi-an, Shaanxi 710071, China. Electronic address: huangly@mail.xidian.edu.cn.
authors.forename: Liyu
authors.initials: L
authors.lastname: Huang
authors.affiliation: School of Life Science and Technology, Xidian University, Xi-an, Shaanxi 710071, China.
authors.forename: Suping
authors.initials: S
authors.lastname: Cai
authors.affiliation: School of Life Science and Technology, Xidian University, Xi-an, Shaanxi 710071, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Life Science and Technology, Xidian University, Xi-an, Shaanxi 710071, 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 710071, China.
authors.forename: Aifeng
authors.initials: A
authors.lastname: Ren
authors.affiliation: School of Life Science and Technology, Xidian University, Xi-an, Shaanxi 710071, China.
authors.forename: Junchan
authors.initials: J
authors.lastname: Ren
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*
keywords: Alzheimer's disease (AD); Default mode network (DMN); Independent component analysis (ICA); Multivariate Granger causality analysis (mGCA)