Glucose Metabolism echoes Long-Range Temporal Correlations in the Human Brain

Area of Science:

• Neuroscience
• Metabolic Regulation
• Systems Biology

Background:

• Intrinsic brain activity exhibits scale-invariant dynamics, characterized by long-range temporal correlations.
• The metabolic cost and regulatory implications of these brain dynamics are not well understood.

Purpose of the Study:

• To investigate the relationship between long-range temporal correlations in intrinsic brain activity and individual-level glucose metabolism.
• To explore the energetic demands associated with scale-invariant brain dynamics.

Main Methods:

• Integration of resting-state functional Magnetic Resonance Imaging (fMRI) and dynamic [18F]FDG Positron Emission Tomography (PET) data.
• Quantification of long-range temporal correlations using the Hurst exponent.

Main Results:

• A systematic relationship was found between the Hurst exponent and glucose metabolism.
• Brains with higher long-range temporal correlations exhibited greater glucose metabolism, indicating a metabolic cost.
• Evidence suggests these dynamics are supported by continuous biosynthetic processes like protein synthesis.

Conclusions:

• Spontaneous long-range temporal correlations in brain activity incur a significant metabolic cost, primarily through glucose utilization.
• These dynamics are crucial for neural circuit maintenance and remodeling, consuming a substantial portion of the brain's energy budget.
• Understanding this energy expenditure provides insights into the fundamental principles of brain function and regulation.