Human Cerebral Cortex Organization Characterized by Functional PET-FDG "Metabolic Connectivity"

Area of Science:

• Neuroscience
• Brain Imaging
• Metabolic Connectivity

Background:

• Resting-state functional connectivity (RSFC) is well-studied using fMRI.
• The spatial organization of brain metabolism at rest is less understood.
• Metabolic connectivity provides insights into the brain's energetic framework.

Purpose of the Study:

• To characterize the spatiotemporal organization of resting-state metabolic connectivity (RSMC) in the human brain using [18F]-fluorodeoxyglucose functional PET (fPET-FDG).
• To examine the relationship between RSMC organization and RSFC.
• To explore how RSMC relates to cortical organization principles.

Main Methods:

• Analyzed resting-state fPET-FDG data from 24 individuals.
• Utilized connectivity-based boundary mapping for local metabolic organization.
• Employed community detection and principal gradient analyses for global metabolic organization.
• Investigated the influence of temporal-frequency-specific fPET-FDG signals.
• Related metabolic gradients to anatomical, functional, and energetic measures.

Main Results:

• Local RSMC showed structured transitions, partly overlapping with RSFC.
• Global RSMC revealed a robust organization along a superior-inferior cortical gradient.
• This gradient was primarily driven by low-frequency fPET-FDG dynamics.
• The metabolic organization aligns with known anatomical and energetic constraints.

Conclusions:

• Characterized the spatiotemporal organizational principles of RSMC.
• Deepened understanding of the brain's energetic framework.
• Provided a foundation for future cognitive and clinical studies on metabolic connectivity.