One way to spot The Invisible Man would be to send him out in the rain – patterns left by the water falling against his body would be a total giveaway. Researchers are using a similar principle to study human brains. Individual bundles of nerve fibres are invisible to many brain imaging techniques, yet here they are – traced out in rainbow colours in this human brain model. A technique called diffusion tensor imaging (DTI) watches water sloshing around the brain, recording how its motion changes when falling against, or running down, nerve bundles in different brain regions. Modelling these tiny changes in water current with a technique called tractography reveals nerves bundles linking the left and right sides of the brain (red), the front and back (green) and running bottom to top (blue) – otherwise invisible patterns that can be used to specifically compare healthy and injured brains.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.