White matter fibres in the brain


Neuroscientists want to understand how our brain pathways link up

Neuroscientists see the brain as consisting of hundreds of specialised areas organised into multiple interconnected networks. They use imaging to visualise the white matter tracts that form connections within and between networks and examine how the connections break in diseases such as stroke. One method that is increasingly being used for this is diffusion tensor imaging (DTI) tractography, a form of MRI that detects the diffusion of water molecules along axons.

DTI tractography reveals the brain’s largest pathways. In 2012, Harvard researchers used it to image large fibres throughout the entire brain for the first time. Researchers at Cardiff University are developing a more advanced method, called DTI tractometry, to image the microscopic structure of the pathways and provide details such as the density and diameter of the axons in the tracts. Some of this work is part of a larger project called the Human Connectome Project, which some researchers say is too ambitious. If it is eventually possible to produce a complete map of the connections in the brain, even that will not tell us everything about how the brain works.

Lead image:

DTI tractography image showing the white matter fibres in the uncinate fasciculus, which connects the frontal and temporal brain regions.

Christopher Whelan, Royal College of Surgeons in Ireland/Wellcome Collection CC BY


About this resource

This resource was first published in ‘Inside the Brain’ in January 2013 and reviewed and updated in November 2017.

Inside the Brain
Education levels:
16–19, Continuing professional development