title: Physical activity over a decade modifies age-related decline in perfusion, gray matter volume, and functional connectivity of the posterior default-mode network-A multimodal approach.
abstract: One step toward healthy brain aging may be to entertain a physically active lifestyle. Studies investigating physical activity effects on brain integrity have, however, mainly been based on single brain markers, and few used a multimodal imaging approach. In the present study, we used cohort data from the Betula study to examine the relationships between scores reflecting current and accumulated physical activity and brain health. More specifically, we first examined if physical activity scores modulated negative effects of age on seven resting state networks previously identified by Salami, Pudas, and Nyberg (2014). The results revealed that one of the most age-sensitive RSN was positively altered by physical activity, namely, the posterior default-mode network involving the posterior cingulate cortex (PCC). Second, within this physical activity-sensitive RSN, we further analyzed the association between physical activity and gray matter (GM) volumes, white matter integrity, and cerebral perfusion using linear regression models. Regions within the identified DMN displayed larger GM volumes and stronger perfusion in relation to both current and 10-years accumulated scores of physical activity. No associations of physical activity and white matter integrity were observed. Collectively, our findings demonstrate strengthened PCC-cortical connectivity within the DMN, larger PCC GM volume, and higher PCC perfusion as a function of physical activity. In turn, these findings may provide insights into the mechanisms of how long-term regular exercise can contribute to healthy brain aging.
authors.affiliation: Center for Demographic and Aging Research (CEDAR), Umeå University, 901 87 Umeå, Sweden; Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 901 87 Umeå, Sweden. Electronic address: cj.boraxbekk@umu.se.
authors.forename: Carl-Johan
authors.initials: CJ
authors.lastname: Boraxbekk
authors.affiliation: Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 901 87 Umeå, Sweden; Aging Research Center (ARC), Karolinska Institute, Stockholm, Sweden.
authors.forename: Alireza
authors.initials: A
authors.lastname: Salami
authors.affiliation: Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 901 87 Umeå, Sweden; Radiation Physics, Department of Radiation Sciences, Umeå University, 901 87 Umeå, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Wåhlin
authors.affiliation: Umeå Center for Functional Brain Imaging (UFBI), Umeå University, 901 87 Umeå, Sweden; Physiology Section, Department of Integrative Medical Biology, Umeå University, 901 87 Umeå, Sweden; Diagnostic Radiology, Department of Radiation Sciences, Umeå University, 901 87 Umeå, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Nyberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003198:Computer Simulation; D063132:Connectome; D015444:Exercise / Q000502:physiology*; D005260:Female; D066128:Gray Matter / Q000033:anatomy & histology / Q000502:physiology*; D006179:Gyrus Cinguli / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D015233:Models, Statistical; D009415:Nerve Net / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D009929:Organ Size / Q000502:physiology; D012146:Rest / Q000502:physiology; D055815:Young Adult
keywords: DMN; Perfusion; Physical activity; Resting state networks; fMRI