Race modifies default mode connectivity in Alzheimer's disease

• Type of Material: Article
• Authors: Maria B. Misiura, Georgia State University; J. Christina Howell, Emory University; Junjie Wu, Emory University; Deqiang Qiu, Emory University; Monica Parker, Emory University; Jessica A. Turner, Georgia State University; William Hu, Emory University
• Language: English
• Date: 2020-02-19
• Publisher: BMC
• Publication Version: Final Published Version
• Copyright Statement: © 2020 The Author(s).
• License: Creative Commons Universal : Public Domain Dedication
• Final Published Version (URL): http://dx.doi.org/10.1186/s40035-020-0186-4
• Title of Journal or Parent Work: Translational Neurodegeneration
• Volume: 9
• Issue: 1
• Start Page: 8
• End Page: 8
• Grant/Funding Information: This work was supported by National Institutes of Health grants AG43885, AG42856, AG25688, and AG61660.
• Keywords: DEMENTIA; NETWORK; Functional connectivity; Neurosciences; BRAIN ACTIVITY; STRESS; RISK; FUNCTIONAL CONNECTIVITY; Default mode network; Disparities; Cognitive impairment; SUBSYSTEMS; AFRICAN-AMERICANS; Science & Technology; MILD COGNITIVE IMPAIRMENT; Alzheimer's disease; MRI; Neurosciences & Neurology; Life Sciences & Biomedicine
• Research Categories: Biology, Neuroscience

Abstract

Background: Older African Americans are more likely to develop Alzheimer's disease (AD) than older Caucasians, and this difference cannot be readily explained by cerebrovascular and socioeconomic factors alone. We previously showed that mild cognitive impairment and AD dementia were associated with attenuated increases in the cerebrospinal fluid (CSF) levels of total and phosphorylated tau in African Americans compared to Caucasians, even though there was no difference in beta-amyloid 1-42 level between the two races. Methods: We extended our work by analyzing early functional magnetic resonance imaging (fMRI) biomarkers of the default mode network in older African Americans and Caucasians. We calculated connectivity between nodes of the regions belonging to the various default mode network subsystems and correlated these imaging biomarkers with non-imaging biomarkers implicated in AD (CSF amyloid, total tau, and cognitive performance). Results: We found that race modifies the relationship between functional connectivity of default mode network subsystems and cognitive performance, tau, and amyloid levels. Conclusion: These findings provide further support that race modifies the AD phenotypes downstream from cerebral amyloid deposition, and identifies key inter-subsystem connections for deep imaging and neuropathologic characterization.