3-D brain atlas wows researchers with microscopic detail

The Washington Post, AFP-JIJI, AP

A 65-year-old woman’s brain was cut into 7,400 slices to create the most detailed three-dimensional atlas of the human brain ever made, bringing researchers one step closer to reverse-engineering the organ’s convoluted circuitry.

Brain atlases are essential reference tools for researchers and physicians. They are needed to determine which areas are “lighting up” during a task or thought process, or during image-guided surgery. The higher the resolution of the atlas, the better doctors can target ever-smaller parts of the brain and their individual functions.

The atlas’ creators, who are from Canada and Germany, have made the ultra-high-resolution model, which is 50 times more detailed than a typical scan, publicly available in a free online format at BigBrain.Loris.ca., and published their work in the journal Science on Thursday.

The atlas, called BigBrain, offers a common basis for open, worldwide scientific discussions on the organ, said co-author Karl Zilles of the Heinrich Heine University Duesseldorf.

It is “the first-ever brain model in 3-D which really presents a realistic human brain with all the cells and all the structures of a human brain,” said Zilles.

Zilles pointed to a novel treatment for Parkinson’s disease called deep brain stimulation, where electrical impulses are sent through electrodes implanted into specific points in the brain. He said BigBrain may open the doors for more accurate localization of electrode placement and thus make treatment more effective.

After staining and digitizing the thousands of slices, which resemble sheets of plastic wrap, the map, which has nearly cellular resolution, revealed the network of layers, fibers and microcircuits that made up the woman’s brain.

The researchers chose the woman’s brain for no special reason other than it was basically healthy, said Katrin Amunts of Heinrich Heine University, the lead author of the report.

While variation exists across different ages and individuals, brains have largely the same distribution of brain structures and anatomy, said author Alan Evans of McGill University’s Montreal Neurological Institute.

There are “subtle shape changes among individuals,” but all atlases start from one representative brain and go from there.

“We’ve raised the level of insight orders of magnitude beyond what was possible at the turn of the 20th century,” said Evans. “This data set will revolutionize our ability to understand internal brain organization.”

The team was chiefly limited by computing power and capacity. To map the human brain with a spatial resolution of 1 micron, which has been done for mouse brains, the atlas would take up 21,000 terabytes of data — essentially rendering it impossible to navigate.

By comparison, BigBrain, with its resolution of 20 microns, comprises about a terabyte of data. Prior MRI-based atlases had resolution of 1 millimeter.

Richard Leigh, a Johns Hopkins University neurologist, said he is looking forward to test-driving BigBrain for his research on stroke recovery. With the microscopic detail available, Leigh can see which particular groups of neurons are growing through stroke treatment rather than just a general fuzzy area.

Evans was in Seattle on Wednesday working with the Allen Institute for Brain Science. Established by Microsoft co-founder Paul Allen, who has committed $500 million since its start in 2003, the Allen Institute has assembled a less-detailed brain atlas of its own.

BigBrain is part of the European Union’s Human Brain Project that brings specialists in neuroscience, medicine and computing together to decipher the mysteries of the brain.

President Barack Obama announced in April an initiative to map the human brain, describing it as a way to discover cures for neurological diseases and to strengthen the economy.