Task-evoked metabolic demands of the posteromedial default mode network are shaped by dorsal attention and frontoparietal control networks.
Godber M Godbersen, Sebastian Klug, Wolfgang Wadsak, Verena Pichler, Julia Raitanen, Anna Rieckmann, Lars Stiernman, Luca Cocchi, Michael Breakspear, Marcus Hacker, Rupert Lanzenberger, Andreas Hahn
Elife May 25, 2023 DOI: 10.7554/elife.84683 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational neuroimaging study combining functional PET/MRI with previously published datasets Peer reviewed |
|---|---|
| Sample size | 50 |
| Population | Healthy human subjects |
| Intervention | motor stimulation |
| Measures | functional PET/MRI, fMRI BOLD signal, glucose metabolism |
| Topics | Default mode network |
| Keywords | Nerve net Humans Magnetic resonance imaging Brain mapping Memory, short-term Attention Deactivation Glucose metabolism Bold signal Functional PET |
| Key findings | Glucose metabolism in the posteromedial default mode network is shaped in opposing directions by the dorsal attention and frontoparietal networks. External-attention tasks consistently reduced both metabolism and BOLD signal in this region, while working memory cognitive control produced a metabolically expensive BOLD suppression, suggesting two types of BOLD deactivation with different oxygen-to-glucose indices. |
Abstract
External tasks evoke characteristic fMRI BOLD signal deactivations in the default mode network (DMN). However, for the corresponding metabolic glucose demands both decreases and increases have been reported. To resolve this discrepancy, functional PET/MRI data from 50 healthy subjects performing Tetris were combined with previously published data sets of working memory, visual and motor stimulation. We show that the glucose metabolism of the posteromedial DMN is dependent on the metabolic demands of the correspondingly engaged task-positive networks. Specifically, the dorsal attention and frontoparietal network shape the glucose metabolism of the posteromedial DMN in opposing directions. While tasks that mainly require an external focus of attention lead to a consistent downregulation of both metabolism and the BOLD signal in the posteromedial DMN, cognitive control during working memory requires a metabolically expensive BOLD suppression. This indicates that two types of BOLD deactivations with different oxygen-to-glucose index may occur in this region. We further speculate that consistent downregulation of the two signals is mediated by decreased glutamate signaling, while divergence may be subject to active GABAergic inhibition. The results demonstrate that the DMN relates to cognitive processing in a flexible manner and does not always act as a cohesive task-negative network in isolation.
Comparable studies
Other experimental studies on default mode network, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Functional connectivity of default mode network components: Correlation, anticorrelation, and causality Healthy subjects | 2008 | Observational study using resting-state fMRI and seed correlation analysis | |
| Patterns of Brain Activity Supporting Autobiographical Memory, Prospection, and Theory of Mind, and Their Relationship to the Default Mode Network Healthy subjects | 2009 | Experimental study using fMRI | |
| Dynamic reconfiguration of the default mode network during narrative comprehension Human subjects | 2016 | Experimental study | |
| Broadband Cortical Desynchronization Underlies the Human Psychedelic State Healthy human participants | 2013 | Experimental study | |
| The brain on art: intense aesthetic experience activates the default mode network Human observers | 2012 | Observational study with fMRI and behavioral analysis |
Citations in the library
Cites 6
- A default mode of brain function Proceedings of the National Academy of Sciences January 16, 2001
- The Brain's Default Mode Network Annual Review of Neuroscience May 4, 2015
- The default mode network in cognition: a topographical perspective Nature Reviews Neuroscience July 5, 2021
- Fractionating the Default Mode Network: Distinct Contributions of the Ventral and Dorsal Posterior Cingulate Cortex to Cognitive Control Journal of Neuroscience March 2, 2011
- Optogenetic stimulation of anterior insular cortex neurons in male rats reveals causal mechanisms underlying suppression of the default mode network by the salience network. Nature Communications February 16, 2023
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