An eight month randomized controlled exercise intervention alters resting state synchrony in overweight children

Abstract

Children with low aerobic fitness have altered brain function compared to higher-fit children. This study examined the effect of an 8-month exercise intervention on resting state synchrony. Twenty-two sedentary, overweight (body mass index ≥85th percentile) children 8-11 years old were randomly assigned to one of two after-school programs: aerobic exercise (n=13) or sedentary attention control (n=9). Before and after the 8-month programs, all subjects participated in resting state functional magnetic resonance imaging scans. Independent components analysis identified several networks, with four chosen for between-group analysis: salience, default mode, cognitive control, and motor networks. The default mode, cognitive control, and motor networks showed more spatial refinement over time in the exercise group compared to controls. The motor network showed increased synchrony in the exercise group with the right medial frontal gyrus compared to controls. Exercise behavior may enhance brain development in children.

Keywords: AFNI; ANOVA; Analysis of Functional Neuroimages; BOLD; CAS; CC; Cognitive Assessment System; DMN; FMRIB Software Libraries; FOV; FSL; ICA; Independent Component Analysis; MNI; Montreal Neurological Institute; RSNs; TE; TR; aerobic exercise; analysis of variance; blood oxygenation level-dependent; cognitive control; default mode; default mode network; development; echo time; fMRI; field of view; functional magnetic resonance imaging; obesity; repetition time; resting state fMRI; resting state networks; rsfMRI.

Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Figures

Figure 1

Salience network. Axial slices (top left z = -26 through bottom right z = 62, spacing = 8 mm) displaying the salience network across all participants and both time points. Scale indicates z-value. The background anatomical image is the pediatric template that was used during alignment and is shown using radiological convention.

Figure 2

Default mode network. Axial slices (top left z = -26 through bottom right z = 62, spacing = 8 mm) displaying the default mode network across all participants and both time points. Scale indicates z-value. The arrow points to the left middle occipital gyrus, which showed a significant group by time interaction. The region is blue, indicating that the exercise group showed decreased synchrony with the DMN over time compared to the control group. The background anatomical image is the pediatric template that was used during alignment and is shown using radiological convention.

Figure 3

Cognitive control network. Axial slices (top left z = -26 through bottom right z = 62, spacing = 8 mm) displaying the cognitive control network across all participants and both time points. Scale indicates z-value. Arrow 2 points to the right culmen and arrow 3 points to the cingulate, both of which showed significant group by time interactions. Both regions are blue, indicating that the exercise group showed decreased synchrony with the cognitive control network over time compared to the control group. Where the clusters overlap with the cognitive control network, the overlap is in green. The background anatomical image is the pediatric template that was used during alignment and is shown using radiological convention.

Figure 4

Motor network. Axial slices (top left z = -26 through bottom right z = 62, spacing = 8 mm) displaying the motor network across all participants and both time points. Scale indicates z-value. Arrow 4 points to the left cuneus and arrow 5 points to the right medial frontal gyrus, both of which showed significant group by time interactions. The left cuneus is blue, indicating that the exercise group showed decreased synchrony with the motor network over time compared to the control group. The right medial frontal gyrus is red, indicating that the interaction was in the opposite direction, with the exercise group showing increased synchrony with the motor network over time compared to the control group. The background anatomical image is the pediatric template that was used during alignment and is shown using radiological convention.