Structure-function coupling in the human brainstem

Area of Science:

• Neuroscience
• Neuroimaging
• Connectomics

Background:

• Brainstem nuclei are crucial for modulating central nervous system activity.
• Brainstem nuclei are typically excluded from brain connectome reconstructions due to imaging challenges.
• The impact of brainstem nuclei on brain structure-function coupling remains largely unknown.

Purpose of the Study:

• To reconstruct structural and functional brain connectomes that include brainstem nuclei.
• To investigate the relationship between brainstem nuclei and cortical structures.
• To understand how brainstem nuclei influence structure-function coupling across the brain.

Main Methods:

• Utilized high-resolution 7 Tesla magnetic resonance imaging (MRI).
• Reconstructed structural and functional connectomes encompassing the cortex and 58 brainstem nuclei (midbrain, pons, medulla).
• Analyzed structural connectional profiles and their correlation with functional connectivity.

Main Results:

• Identified structural connectional profiles of brainstem nuclei to the cortex, aligning with sensory, motor, and cognitive functions.
• Demonstrated a positive correlation between structural and functional connectivity in brainstem-augmented connectomes.
• Found heterogeneous structure-function coupling across brainstem nuclei, with highest coupling in modulatory and relay nuclei.

Conclusions:

• This work provides an initial framework for understanding the brainstem's influence on brain-wide structure-function relationships.
• The findings highlight the importance of including brainstem nuclei in connectomic studies.
• Brainstem nuclei play a significant role in shaping cognitive and sensory-motor functions through their connectivity patterns.