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. 2011:2011:535816.
doi: 10.4061/2011/535816. Epub 2011 Jun 14.

The default mode network in healthy aging and Alzheimer's disease

Katell Mevel  1 , Gaël Chételat, Francis Eustache, Béatrice Desgranges
Affiliations

The default mode network in healthy aging and Alzheimer's disease

Katell Mevel et al. Int J Alzheimers Dis. 2011.

Abstract

In the past decade, a "default mode network" (DMN) has been highlighted in neuroimaging studies as a set of brain regions showing increased activity in task-free state compared to cognitively demanding task, and synchronized activity at rest. Changes within this network have been described in healthy aging as well as in Alzheimer's disease (AD) and populations at risk for AD, that is, amnestic Mild Cognitive Impairment (aMCI) patients and APOE-ε4 carriers. This is of particular interest in the context of early diagnosis and more generally for our understanding of the physiopathological mechanisms of AD. This paper gives an overview of the anatomical and physiological characteristics of this network as well as its relationships with cognition, before focusing on changes in the DMN over normal aging and Alzheimer's disease. While perturbations of the DMN have been consistently reported, especially within the posterior cingulate, further studies are needed to understand their clinical implication.

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Figures

Figure 1
Figure 1
Resting-state fMRI cerebral activity in 71 healthy subjects aged from 19 to 80 years (a) Using an Independent Component Analysis, we identified the Default Mode Network (DMN) encompassing here the posterior cingulate/precuneus, anterior cingulate, orbitofrontal, ventromedial prefrontal, inferior temporal cortices, hippocampi, and angular gyri. (b) Using the posterior cingulate cortex (PCC) as a seed in a functional connectivity analysis, we identified a larger network extending to frontal, occipital, and middle temporal regions, as well as cerebellum, thalami, and motor cortices. Using this same method on (c) amnestic Mild Cognitive Impairment (aMCI) and Alzheimer's disease (AD) patients, a disruption of the connectivity between PCC and anterior then posterior brain areas was observed. (d) 18FDG-PET resting-state measures in two groups of aMCI and AD patients compared to healthy aged controls. While in the former group, hypometabolism was restricted to PCC and subcortical structures, it mainly extended to temporoparietal regions in the latter group.
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References

    1. Ghatan PH, Hsieh JC, Wirsen-Meurling A, et al. Brain activation induced by the perceptual maze test: a PET study of cognitive performance. NeuroImage. 1995;2(2):112–124. - PubMed
    1. Hutchinson M, Schiffer W, Joseffer S, et al. Task-specific deactivation patterns in functional magnetic resonance imaging. Magnetic Resonance Imaging. 1999;17(10):1427–1436. - PubMed
    1. Gusnard DA, Raichle ME. Searching for a baseline: functional imaging and the resting human brain. Nature Reviews Neuroscience. 2001;2(10):685–694. - PubMed
    1. Newman SD, Twieg DB, Carpenter PA. Baseline conditions and subtractive logic in neuroimaging. Human Brain Mapping. 2001;14(4):228–235. - PMC - PubMed
    1. McKiernan KA, Kaufman JN, Kucera-Thompson J, Binder JR. A parametric manipulation of factors affecting task-induced deactivation in functional neuroimaging. Journal of Cognitive Neuroscience. 2003;15(3):394–408. - PubMed

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