Brain tractography: visualising neuronal tracts

Credit Nuada Medical , Wellcome Images, 2011 Wellcome Image Award winner.

This image shows the neuronal tracts in the brain of an adult male, viewed from above. These tracts correspond to bundles of axons, which are the elongated projections that extend from neurons. They form the critical connective 'wiring' that transmits information between neurons within the brain, and to those elsewhere in the body for sensory and motor function.

This image has been created using an MRI scanner and an advanced method called diffusion tensor imaging (DTI), which is sensitive to the movement (diffusion) of water molecules in the tissue. Water is able to diffuse more freely along the length of the neuronal tract rather than across it; so, by measuring the main direction of this water movement, this technique can provide directional information on the tracts and allow them to be seen in a living brain. A colour palette is applied to represent the directional information and superimposed on the 3D structural brain image to create the image shown here.