TY - JOUR
T1 - Resting-state connectivity of the left frontal cortex to the default mode and dorsal attention network supports reserve in mild cognitive impairment
AU - Franzmeier, Nicolai
AU - Göttler, Jens
AU - Grimmer, Timo
AU - Drzezga, Alexander
AU - Áraque-Caballero, Miguel A.
AU - Simon-Vermot, Lee
AU - Taylor, Alexander N.W.
AU - Bürger, Katharina
AU - Catak, Cihan
AU - Janowitz, Daniel
AU - Müller, Claudia
AU - Duering, Marco
AU - Sorg, Christian
AU - Ewers, Michael
N1 - Publisher Copyright:
© 2017 Franzmeier, Göttler, Grimmer, Drzezga, áraque-Caballero, Simon-Vermot, Taylor, Bürger, Catak, Janowitz, Müller, Duering, Sorg and Ewers.
PY - 2017/8/7
Y1 - 2017/8/7
N2 - 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.
AB - 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.
KW - Cognitive reserve
KW - Frontoparietal control network
KW - Functional connectivity
KW - Memory
KW - Mild cognitive impairment
UR - http://www.scopus.com/inward/record.url?scp=85027191359&partnerID=8YFLogxK
U2 - 10.3389/fnagi.2017.00264
DO - 10.3389/fnagi.2017.00264
M3 - Article
AN - SCOPUS:85027191359
SN - 1663-4365
VL - 9
JO - Frontiers in Aging Neuroscience
JF - Frontiers in Aging Neuroscience
IS - AUG
M1 - 264
ER -