Correspondence between Cerebral Glucose Metabolism and BOLD Reveals Relative Power and Cost in Human Brain
Research Article
Abstract
Introduction
The correspondence between cerebral glucose metabolism (indexing energy utilization) and synchronous fluctuations in blood oxygenation (indexing neuronal activity) is relevant for neuronal specialization and is affected by brain disorders.
Method
The study defines novel measures of relative power (rPWR, extent of concurrent energy utilization and activity) and relative cost (rCST, extent that energy utilization exceeds activity), derived from FDG-PET and fMRI.
Results
The study shows that resting-state networks have distinct energetic signatures and that brain could be classified into major bilateral segments based on rPWR and rCST. While medial-visual and default-mode networks have the highest rPWR, frontoparietal networks have the highest rCST. rPWR and rCST estimates are generalizable to other indexes of energy supply and neuronal activity, and are sensitive to neurocognitive effects of acute and chronic alcohol exposure.
Conclusion
rPWR and rCST are informative metrics for characterizing brain pathology and alternative energy use, and may provide new multimodal biomarkers of neuropsychiatric disorders.
The study found both acute and chronic exposure to alcohol affected power (rPWR) and cost (rCST) of brain regions. In conclusion, despite widespread decreases in glucose metabolism in heavy alcohol users compared to light alcohol users, heavy alcohol use shifts the brain toward less efficient energetic states.