Open AccessDissociations between glucose metabolism and blood oxygenation in the human default mode network revealed by simultaneous PET-fMRI
Author(s) -
Lars Jonasson,
Filip Grill,
Andreas Hahn,
Lucas Rischka,
Rupert Lanzenberger,
Vania Panes Lundmark,
Katrine Riklund,
Jan Axelsson,
Anna Rieckmann
Publication year - 2021
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2021913118
Subject(s) - default mode network , neuroscience , resting state fmri , cognition , positron emission tomography , functional magnetic resonance imaging , blood oxygenation , psychology , neuroimaging , premovement neuronal activity
Significance A consistent finding from functional MRI (fMRI) of externally focused cognitive control is negative signal change in the brain’s default mode network (DMN), but it is unknown whether this reflects an increase of synaptic activity during rest periods or active suppression during task. Using hybrid PET-MRI, we show that task-positive fMRI responses align with increasing glucose metabolism during cognitive control, but task-negative fMRI responses in DMN are not accompanied by corresponding decreases in metabolism. The results are incompatible with an interpretation of task-negative fMRI signal in DMN as a relative metabolic increase during a resting baseline condition. The present results open up avenues for understanding abnormal fMRI activity patterns in DMN in aging and psychiatric disease.