Anybody with experience of gross anatomy dissections, intricate surgical work or just paper cutting, will know that having patience is a prerequisite, to say the least. So we can only begin to imagine the patience required to prepare and scan more than 7,400 extremely delicate slices from a single brain over a 10-year period. This momentous work was undertaken as part of the European Human Brain project and has been dubbed the BigBrain Atlas.
The objective of the BigBrain Atlas is to provide an accessible, highly accurate 3D anatomical model of the human brain. The Atlas has 50 times the spatial resolution of previous models and has a layer spacing of 20 micrometers, enabling individual neurons and their connections to be viewed. The project began in 2003 and was led by Katrin Amunts, a neuroanatomist at the Research Centre Jülich in Germany, along with a team of international collaborators.
The researchers have published details of the project in the journal Science this week. According to the article, the brain was that of a healthy 65 year-old donor and was extremely labor-intensive to scan owing to the ultra-high resolution required :
After preserving the brain in formalin, a chemical fixative, and embedding it in wax for several months, they began to cut it using a knife called a microtome, which carves linked sections onto a conveyer belt like a deli slicer cutting turkey breast…
…Next, the researchers mounted each slice on a microscope slide, stained it to make the cell bodies of neurons visible, and scanned it. Overall, it took about 1000 hours of nearly continuous labor to prepare and scan each brain slice and the researchers obtained more than 7400 slices in all.
The Big Brain model is currently available to researchers with the appropriate credentials, but it would appear that a larger objective of the parent European Human Brain project is to make this data available to as large an audience as possible. But for now, let’s hope our credentials check out.