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The role of the arousal system in age-related differences in cortical functional network architecture.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Guardia, Tiago 
Geerligs, Linda 
Tsvetanov, Kamen A.  ORCID logo  https://orcid.org/0000-0002-3178-6363
Ye, Rong 
Campbell, Karen L 

Abstract

A common finding in the aging literature is that of the brain's decreased within- and increased between-network functional connectivity. However, it remains unclear what is causing this shift in network organization with age. Given the essential role of the ascending arousal system (ARAS) in cortical activation and previous findings of disrupted ARAS functioning with age, it is possible that age differences in ARAS functioning contribute to disrupted cortical connectivity. We test this possibility here using resting state fMRI data from over 500 individuals across the lifespan from the Cambridge Center for Aging and Neuroscience (Cam-CAN) population-based cohort. Our results show that ARAS-cortical connectivity declines with age and, consistent with our expectations, significantly mediates some age-related differences in connectivity within and between association networks (specifically, within the default mode and between the default mode and salience networks). Additionally, connectivity between the ARAS and association networks predicted cognitive performance across several tasks over and above the effects of age and connectivity within the cortical networks themselves. These findings suggest that age differences in cortical connectivity may be driven, at least in part, by altered arousal signals from the brainstem and that ARAS-cortical connectivity relates to cognitive performance with age.

Description

Keywords

ascending arousal system, fMRI, functional networks, neurocognitive aging

Journal Title

Human Brain Mapping

Conference Name

Journal ISSN

1065-9471
1097-0193

Volume Title

Publisher

Wiley Open Access
Sponsorship
Biotechnology and Biological Sciences Research Council (BB/H008217/1)
British Academy (pf160048)
Guarantors of Brain (Unknown)
Medical Research Council (MR/J009482/1)
Medical Research Council (MC_U105597119)
Medical Research Council (MC_UU_00005/12)