Structural-Functional Connectivity in Human Brain Networks

The human brain comprises a complex web of anatomical pathways and dynamic interactions. Structural connectivity, mapped through diffusion-based imaging, delineates the physical white-matter tracts linking cortical and subcortical regions. Functional connectivity, often measured by correlated activity patterns in functional magnetic resonance imaging, reveals how disparate areas co-activate during tasks or at rest. The relationship between these two dimensions—structure–function coupling—varies across spatial scales and functional systems. In primary sensory regions, tight alignment of white-matter pathways and coherent activity supports rapid stimulus processing, whereas higher-order association cortices exhibit more flexible coupling, allowing integration across modalities and cognitive states. Multimodal approaches, integrating microstructural measures such as myelin content and excitation–inhibition ratios, have refined models of how anatomical constraints and local physiology produce the emergent patterns of network communication. This interplay underpins perceptual processing, memory, executive control and is reshaped in neurological disorders, making it a central theme for understanding brain function and dysfunction.

Research from Nature Portfolio

Recent work has shown that intracortical myelination and the balance of excitatory and inhibitory signalling jointly determine the regional strength and temporal variability of structure–function coupling. This study revealed a gradient from rigid coupling in heavily myelinated sensory areas to more labile interactions in transmodal cortex, driven by shifting contributions of myelin and excitation–inhibition balance. A complementary investigation quantified how structure–function coupling varies across individuals and networks, demonstrating that coupling strength is highly heritable in visual and subcortical systems and correlates with age, sex and cognitive performance. A foundational study introduced a structural-decoupling index to map a macroscale gradient spanning tightly coupled primary regions to decoupled association areas, aligning with behavioural hierarchies from perception to abstract thought. Together, these contributions establish biological mediators and genetic influences that shape the nuanced interplay between anatomy and function.

Structural-Functional Connectivity in Human Brain Networks publication trend

The graph below shows the total number of articles in structural-functional connectivity in human brain networks across all publications each year (not limited to Nature Index journals).

Technical terms

Structural connectivity: The anatomical network of white-matter tracts linking neuronal populations.

Functional connectivity: Statistical dependencies between activity patterns of distinct brain regions.

Structure–function coupling: The degree to which anatomical pathways constrain or predict functional interactions.

Myelination: The process of forming a myelin sheath around axons, influencing signal conduction speed and network dynamics.

Excitation–inhibition balance: The ratio of excitatory to inhibitory neural signalling that modulates local circuit stability and temporal flexibility.

References

1. Myelination and excitation-inhibition balance synergistically shape structure-function coupling across the human cortex. Nature Communications (2023).
2. Heritability and interindividual variability of regional structure-function coupling. Nature Communications (2021).
3. Decoupling of brain function from structure reveals regional behavioral specialization in humans. Nature Communications (2019).
4. Information decomposition and the informational architecture of the brain. Trends in Cognitive Sciences (2024).
5. Impaired long-range excitatory time scale predicts abnormal neural oscillations and cognitive deficits in Alzheimer’s disease. Alzheimer's Research & Therapy (2024).
6. Linking Structure and Function in Macroscale Brain Networks. Trends in Cognitive Sciences (2020).