Resting-State Connectivity of the Left Frontal Cortex to the Default Mode and Dorsal Attention Network Supports Reserve in Mild Cognitive Impairment

Franzmeier, Nicolai, Göttler, Jens, Grimmer, Timo, Drzezga, Alexander, Áraque-Caballero, Miguel A., Simon-Vermot, Lee, Taylor, Alexander N. W., Bürger, Katharina, Catak, Cihan, Janowitz, Daniel, Müller, Claudia, Duering, Marco, Sorg, Christian and Ewers, Michael (2017) Resting-State Connectivity of the Left Frontal Cortex to the Default Mode and Dorsal Attention Network Supports Reserve in Mild Cognitive Impairment. Frontiers in Aging Neuroscience, 9. ISSN 1663-4365

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    Abstract

    Reserve refers to the phenomenon of relatively preserved cognition in disproportion to the extent of neuropathology, e.g., in Alzheimer’s disease. A putative functional neural substrate underlying reserve is global functional connectivity of the left lateral frontal cortex (LFC, Brodmann Area 6/44). Resting-state fMRI-assessed global LFC-connectivity is associated with protective factors (education) and better maintenance of memory in mild cognitive impairment (MCI). Since the LFC is a hub of the fronto-parietal control network that regulates the activity of other networks, the question arises whether LFC-connectivity to specific networks rather than the whole-brain may underlie reserve. We assessed resting-state fMRI in 24 MCI and 16 healthy controls (HC) and in an independent validation sample (23 MCI/32 HC). Seed-based LFC-connectivity to seven major resting-state networks (i.e., fronto-parietal, limbic, dorsal-attention, somatomotor, default-mode, ventral-attention, visual) was computed, reserve was quantified as residualized memory performance after accounting for age and hippocampal atrophy. In both samples of MCI, LFC-activity was anti-correlated with the default-mode network (DMN), but positively correlated with the dorsal-attention network (DAN). Greater education predicted stronger LFC-DMN-connectivity (anti-correlation) and LFC-DAN-connectivity. Stronger LFC-DMN and LFC-DAN-connectivity each predicted higher reserve, consistently in both MCI samples. No associations were detected for LFC-connectivity to other networks. These novel results extend our previous findings on global functional connectivity of the LFC, showing that LFC-connectivity specifically to the DAN and DMN, two core memory networks, enhances reserve in the memory domain in MCI.

    Item Type: Article
    Uncontrolled Keywords: cognitive reserve,mild cognitive impairment,frontoparietal control network,memory,functional connectivity
    Related URLs:
    Depositing User: Pure Connector
    Date Deposited: 09 Nov 2017 06:07
    Last Modified: 25 Jul 2018 14:15
    URI: https://ueaeprints.uea.ac.uk/id/eprint/65381
    DOI: 10.3389/fnagi.2017.00264

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