Diffusion time-related structure-function coupling reveals differential association with inter-individual variations...

Area of Science:

• Neuroimaging
• Computational Neuroscience
• Obesity Research

Background:

• Inter-individual variations in body mass index (BMI) correlate with altered brain structure and function.
• The precise mechanisms linking BMI to brain structure-function alterations remain unclear.

Purpose of the Study:

• To investigate the relationship between brain structure-function coupling and BMI.
• To explore the neural mechanisms underlying BMI-related brain alterations.

Main Methods:

• Utilized diffusion MRI tractography for structural connectivity and functional MRI for functional connectivity.
• Employed Riemannian optimization to combine structural and functional connectivity data.
• Generated principal eigenvectors (gradients) of connectivity matrices and analyzed their association with BMI.

Main Results:

• Identified a prominent cortical hierarchical organization differentiating sensory and transmodal regions.
• Found the strongest association between functional gradients and BMI when hierarchical structure was most evident.
• Demonstrated that BMI-related structure-function coupling is linked to brain microstructure, especially in higher-order areas.
• Transcriptomic analysis revealed gene enrichment in the striatum, hypothalamus, and cortical cells.

Conclusions:

• Structure-function correspondence in the brain is strongly coupled with BMI, particularly during apparent hierarchical organization.
• These associations are influenced by multiscale brain properties, advancing our understanding of neural mechanisms related to BMI.
• Findings highlight the role of brain microstructure and specific gene enrichments in BMI-related neural alterations.