Structural Variability in the Human Brain Reflects Fine-Grained Functional Architecture at the Population Level

Area of Science:

• Neuroscience
• Human Brain Imaging
• Neuroanatomy

Background:

• The relationship between human brain structure and function is a long-standing question in neuroscience.
• Previous research suggests some structural-functional links, but the extent and granularity remain unclear.

Purpose of the Study:

• To investigate the fine-grained relationship between brain structure and functional organization across the lifespan.
• To identify structural networks that mirror functional connectivity patterns.

Main Methods:

• Utilized a data-driven, multimodal approach on a large cohort (N=484) to study brain structure.
• Analyzed gray matter volume and cortical area covariation to define gray matter networks (GMNs).
• Examined structural signatures in specific brain regions like the cerebellum, visual areas, and default-mode network (DMN).

Main Results:

• Demonstrated that numerous GMNs across the entire brain exhibit a functionally meaningful architecture.
• Revealed fine-grained anatomical signatures corresponding to functional connectivity, including in the cerebellum, visual cortex, and DMN.
• Showed that GMNs cluster to form larger-scale functional organization, linking posterior DMN with its anticorrelated network.

Conclusions:

• The relationship between structural and functional connectivity in the human brain is fine-grained and widespread.
• Covariation in cortical area, driven by factors like shape and folding, underlies this structural-functional architecture.
• Developmental neurotrophic events likely coordinate the size and folding of distant, functionally connected brain regions, influencing cortical specialization.