Coupling of cerebral blood flow and functional connectivity is decreased in healthy aging

• Published in: Brain imaging and behavior 2020-04, Vol.14 (2), p.436-450
• Main Authors: Galiano, Alvaro, Mengual, Elisa, García de Eulate, Reyes, Galdeano, Iñigo, Vidorreta, Marta, Recio, Miriam, Riverol, Mario, Zubieta, José L., Fernández-Seara, María A.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aging; Aging - physiology; Biomedical and Life Sciences; Biomedicine; Blood flow; Brain - physiology; Caudate nucleus; Cerebral blood flow; Cerebral Cortex - physiology; Cerebrovascular Circulation - physiology; Cognition - physiology; Cortex (frontal); Cortex (insular); Cortex (parietal); Coupling; Disruption; Female; Functional magnetic resonance imaging; Geriatrics; Healthy Aging - physiology; Humans; Magnetic Resonance Imaging - methods; Male; Medical imaging; Neural networks; Neural Pathways - physiology; Neuroimaging; Neurology; Neuropsychology; Neuroradiology; Neurosciences; Older people; Original Research; Perfusion; Prefrontal cortex; Prefrontal Cortex - physiology; Psychiatry; Spin labeling; Spin Labels; Thalamus; Thalamus - physiology; Young Adult; Young adults
• ISSN: 1931-7557; 1931-7565
• DOI: 10.1007/s11682-019-00157-w

Aging leads to cerebral perfusion and functional connectivity changes that have been assessed using various neuroimaging techniques. In addition, a link between these two parameters has been demonstrated in healthy young adults. In this work, we employed arterial spin labeling (ASL) fMRI to measure global and voxel-wise differences in cerebral blood flow (CBF) and intrinsic connectivity contrast (ICC) in the resting state in a group of cognitively normal elderly subjects and a group of cognitively normal young subjects, in order to assess the effects of aging on CBF-ICC coupling, which had not been previously evaluated. Our results showed age-related global and regional CBF decreases in prefrontal mesial areas, lateral frontal regions, insular cortex, lateral parietal areas, precuneus and occipital regions. Subcortically, perfusion was reduced in the medial thalamus and caudate nucleus. ICC was also found reduced with age in prefrontal cortical areas and insular cortex, affecting key nodes of the default mode and salience networks. Areas of ICC and CBF decrease partially overlapped, however, the CBF reduction was more extensive and encompassed more areas. This dissociation was accompanied by a decrease in CBF-ICC coupling. These results suggest that aging leads to a disruption in the relationship between CBF and intrinsic functional connectivity that could be due to neurovascular dysregulation.