Local activity determines functional connectivity in the resting human brain: a simultaneous FDG-PET/fMRI study

Area of Science:

• Neuroscience
• Systems Neuroscience
• Clinical Neuroscience

Background:

• Resting-state functional connectivity (rs-FC) using blood oxygenation level-dependent (BOLD) signals is crucial in neuroscience.
• The precise neural basis of rs-FC remains incompletely understood.

Purpose of the Study:

• To investigate the direct relationship between local neuronal activity (LA) and rs-FC in humans.
• To test the hypothesis that a brain region's LA determines its rs-FC.

Main Methods:

• Simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI) was used.
• Local activity (glucose metabolism) and rs-FC (BOLD signal fluctuations) were measured during eyes open and eyes closed conditions.

Main Results:

• Elevated LA in the visual system and salience network correlated with increased rs-FC during eyes open condition.
• LA in the primary visual cortex and anterior cingulate cortex significantly predicted rs-FC patterns.

Conclusions:

• This study provides the first direct evidence in humans linking local neuronal activity to resting-state BOLD functional connectivity.
• The findings offer a novel method for investigating aberrant local dynamics and functional coupling in neuropsychiatric disorders.