he map of the human brain just got an upgrade that’s been more than a century in the making.
Scientists announced Wednesday they had doubled the number of areas identified in the brain’s outer shell, having mapped 180 different regions in the cortex. The gold standard of neurological mapping up until now? A 1909 sketch created by a German neurologist.
The research is part of the Human Connectome Project, a massive effort by the National Institutes of Health to understand the highways of the human brain.
The work could smooth the process thanks to a corresponding algorithm that gives each of those mapped areas a “fingerprint” that can be picked up by specialized MRI scans. Researchers studying how the brain lights up in response to stimuli will now be able to pinpoint where, exactly, they’re able to elicit activity.
A new paper on the map was published in Nature Wednesday. STAT chatted with Matthew Glasser of Washington University in St. Louis, one of the paper’s authors, about the work.
What did you set out to do?
We were trying to make a new map of the cerebral cortex, which is a 1.6- to 4-millimeter sheet that covers the outer surface of the brain. It’s what makes it look folded up and wrinkled and like a brain. The standard map when I first got into neuroimaging was from 1909. It’s a 2-D drawing with about 50 areas, so you’d have to look at the picture and look at your data and try to guess where your data was coming from in the brain.
How does the new map work?
It’s a topographic map of the brain, with an algorithm that’s learned to fingerprint the cortical area of the brain. We found 180 regions — 83 of those we searched and found mentioned in other papers, 97 were new. We identify them by using architectural measures. So the motor cortex is one of the thicker areas, and one of the thinnest areas that regulates touch is nearby. Another architectural measure we used to identify was the amount of insulation around the connections between neurons. There was quite a bit of insulation in some of the gray matter itself, but that differs in different brain areas. We used [that information] to find boundaries.
What are the potential uses for it?
The most obvious one is the research application. Brain imaging investigators do a functional task, and they don’t really know what cortical area that activation they’re seeing is in. Having this map will really make that a lot clearer. Neurosurgeons who need to avoid certain parts of the brain when they’re cutting — because if they damage those parts the patients could be paralyzed or lose the ability to speak — could use the map, too.