White Matter Functional Imaging and Connectivity

White matter has traditionally been viewed as a passive conduit for information transfer between grey matter regions, but recent advances in neuroimaging have revealed that it exhibits its own dynamic patterns of activity and organised networks. Functional magnetic resonance imaging (fMRI) can detect blood-oxygenation-level-dependent (BOLD) fluctuations within white matter tracts, and these signals are increasingly shown to reflect underlying electrophysiological synchrony and structural pathways. By integrating functional measures with diffusion-based tractography, researchers have begun to map how white matter supports inter-regional communication, adapts with development and ageing, and alters in neurological and psychiatric conditions. The result is a more complete picture of the brain’s wiring as a living, functionally engaged system with potential biomarkers for disease progression, cognitive ageing and treatment response.

Research from Nature Portfolio

Recent studies have provided direct evidence that white matter BOLD functional connectivity corresponds to intracranial electrophysiological synchronisation. Recordings from stereotactic-electroencephalography and resting-state fMRI demonstrate that frequency-specific functional correlations in major fibre bundles mirror their structural integrity as revealed by diffusion spectrum imaging. This work establishes an anatomical and physiological basis for white matter networks and points to their utility as biomarkers in epilepsy, psychiatric disorders and beyond. Complementing these findings, precise measurements of the haemodynamic response function in task-evoked white matter tracts have shown distinct temporal characteristics—namely reduced amplitude, delayed onset and extended initial dips—relative to grey matter. These observations call for refined analytic models when studying event-related signals in white matter and underscore the need to tailor processing pipelines to its unique vascular and cellular environment.

White Matter Functional Imaging and Connectivity publication trend

The graph below shows the total number of articles in white matter functional imaging and connectivity across all publications each year (not limited to Nature Index journals).

Technical terms

Blood-oxygenation-level-dependent (BOLD) signal: MR contrast changes reflecting local variations in deoxyhaemoglobin related to neural activity.

Functional connectivity (FC): statistical correlation of signal time courses between distinct brain regions or tracts.

Diffusion spectrum imaging (DSI): advanced diffusion MRI technique that resolves complex fibre orientations in white matter.

Haemodynamic response function (HRF): temporal profile of BOLD signal change following a brief neural event.

Stereotactic-electroencephalography (SEEG): invasive method for recording electrical activity directly from deep brain structures.

Independent component analysis (ICA): computational method for separating spatially independent sources in imaging data.

References

1. Intracranial electrophysiological and structural basis of BOLD functional connectivity in human brain white matter. Nature Communications (2023).
2. Characterization of the hemodynamic response function in white matter tracts for event-related fMRI. Nature Communications (2019).
3. Structure-function coupling in white matter uncovers the abnormal brain connectivity in Schizophrenia. Translational Psychiatry (2023).
4. Changes in white matter functional networks across late adulthood. Frontiers in Aging Neuroscience (2023).