Mapping the billions of connections in the brain is a grand challenge in neuroscience.
The current method for mapping interconnected brain cells involves the use of room-size microscopes known as transmission electron microscopes (TEMs). Until now the process of mapping even small areas of the brain using these massive machines would have required several decades. In this week's open-access journal PLoS Biology, research teams at the University of Utah John A. Moran Eye Center and the University of Colorado at Boulder report technical advances that have reduced the time it takes to process high-speed "color" ultrastructure mapping of brain regions down to a few months.
These advances did not require the invention of new electron microscopes. The technical leap comes mostly from new powerful software that "takes over" the building, connecting and viewing of terabyte scale pictures produced by TEMs. Perhaps just as important is the fact that these researchers are now making these technologies available world-wide to scientists in multiple fields of research. "Our goals were to unleash a global network of electron microscopes and provide web-accessible imagery for battalions of brain network analysts," said Robert Marc, Ph.D., Director of Research for the Moran Eye Center at the University of Utah.
Marc and this team of researchers have been working on this project for eight years. They have refined the software and molecular tools to where they are now able to share them globally. "This changes the playing field for building brain maps from a few specialized laboratories to the desktops of biologists world-wide," says Marc.
The automation tools developed at the University of Colorado at Boulder, Center for 3D Electron Microscopy, allow capture of 25,000 TEM images weekly. At the same time, the Scientific Computing and Imaging Institute at the University of Utah developed software to automatically merge thousands of images into gigabyte-scale mosaics and align the mosaics into terabyte-scale volumes. And in parallel, teams at the Moran Eye Center developed TEM-compatible molecular probes and classification software to tag every cell with a molecular signature, creating "color" TEM imaging.