TY - JOUR
T1 - Progressive bidirectional age-related changes in default mode network effective connectivity across six decades
AU - Li, Karl
AU - Laird, Angela R.
AU - Price, Larry R.
AU - McKay, D. Reese
AU - Blangero, John
AU - Glahn, David C.
AU - Fox, Peter T.
N1 - Funding Information:
This was supported by the National Institutes of Health grant 5R01MH074457-09, Meta-Analysis in Human Brain Mapping. The data was provided for by NIH grant 1R01MH078111-01, the Genetics of Brain Structure, and Function study. Special thanks to Crystal Franklin for help in data pre-processing and Mary Woosley for help in providing demographic information for the data used.
PY - 2016/6/14
Y1 - 2016/6/14
N2 - The default mode network (DMN) is a set of regions that is tonically engaged during the resting state and exhibits task-related deactivation that is readily reproducible across a wide range of paradigms and modalities. The DMN has been implicated in numerous disorders of cognition and, in particular, in disorders exhibiting age-related cognitive decline. Despite these observations, investigations of the DMN in normal aging are scant. Here, we used blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) acquired during rest to investigate age-related changes in functional connectivity of the DMN in 120 healthy normal volunteers comprising six, 20-subject, decade cohorts (from 20-29 to 70-79). Structural equation modeling (SEM) was used to assess age-related changes in inter-regional connectivity within the DMN. SEM was applied both using a previously published, meta-analytically derived, node-and-edge model, and using exploratory modeling searching for connections that optimized model fit improvement. Although the two models were highly similar (only 3 of 13 paths differed), the sample demonstrated significantly better fit with the exploratory model. For this reason, the exploratory model was used to assess age-related changes across the decade cohorts. Progressive, highly significant changes in path weights were found in 8 (of 13) paths: Four rising, and four falling (most changes were significant by the third or fourth decade). In all cases, rising paths and falling paths projected in pairs onto the same nodes, suggesting compensatory increases associated with age-related decreases. This study demonstrates that age-related changes in DMN physiology (inter-regional connectivity) are bidirectional, progressive, of early onset and part of normal aging.
AB - The default mode network (DMN) is a set of regions that is tonically engaged during the resting state and exhibits task-related deactivation that is readily reproducible across a wide range of paradigms and modalities. The DMN has been implicated in numerous disorders of cognition and, in particular, in disorders exhibiting age-related cognitive decline. Despite these observations, investigations of the DMN in normal aging are scant. Here, we used blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) acquired during rest to investigate age-related changes in functional connectivity of the DMN in 120 healthy normal volunteers comprising six, 20-subject, decade cohorts (from 20-29 to 70-79). Structural equation modeling (SEM) was used to assess age-related changes in inter-regional connectivity within the DMN. SEM was applied both using a previously published, meta-analytically derived, node-and-edge model, and using exploratory modeling searching for connections that optimized model fit improvement. Although the two models were highly similar (only 3 of 13 paths differed), the sample demonstrated significantly better fit with the exploratory model. For this reason, the exploratory model was used to assess age-related changes across the decade cohorts. Progressive, highly significant changes in path weights were found in 8 (of 13) paths: Four rising, and four falling (most changes were significant by the third or fourth decade). In all cases, rising paths and falling paths projected in pairs onto the same nodes, suggesting compensatory increases associated with age-related decreases. This study demonstrates that age-related changes in DMN physiology (inter-regional connectivity) are bidirectional, progressive, of early onset and part of normal aging.
KW - Default mode network (DMN)
KW - Functional connectivity (FC)
KW - Meta-analytic connectivity modeling
KW - Normal aging
KW - Structural equation modeling (SEM)
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U2 - 10.3389/fnagi.2016.00137
DO - 10.3389/fnagi.2016.00137
M3 - Article
AN - SCOPUS:84980325780
VL - 8
JO - Frontiers in Aging Neuroscience
JF - Frontiers in Aging Neuroscience
SN - 1663-4365
IS - JUN
M1 - 137
ER -