World's Most Detailed 3D Brain Map Made By Scientists - BigBrain

Scientists have finely sliced a human brain into 7,400 wafer-thin sheets and then reconstructed it to create the world's most detailed map of the brain in three dimensions.

Slicing a brain exposes only two dimensions, so it is often unclear where and how the cells within these folds are organised in three-dimensional space.

The folds, creases and intricate internal structures that make up the human brain are being revealed in unprecedented detail. A new three-dimensional map called BigBrain is the most detailed ever constructed, and should lead to a more accurate picture of how the brain's different regions function and interact. The so-called "Big Brain" project, which took a 65-year-old woman's brain and cut it into more than 7400 sections each just 20 micrometres thick, shows the brain's anatomy in microscopic detail, almost down to a cellular level.

Reassembling these images into a full 3D model of the brain was no easy task. It required 1000 hours on a supercomputer. But because the images' resolution was so high, the computer was able to determine the 3D shape of each fold correctly, even if the slice had been cut at an angle.

Until now, scientists had only been able to study the brain on a scale of about 1 millimetre by 1 millimetre by 1 millimetre, Evans told reporters in a teleconference.

"We're now 50 times smaller in all three dimensions," he said. "This changes the game in terms of our ability to discriminate very fine structural and physiological properties of the human brain."

Because the sliced and reconstructed Big Brain was created from a dead organ, scientists said the best way to imagine it was as a type of scaffold providing a 3D framework for living brain information to be analysed.

Using a special tool called a microtome, the researchers from Canada and Germany sliced the 65-year-old human female brain, which had been embedded in paraffin wax, into more than 7,400 sections.

They then mounted the 20-micrometre thick sections onto slides, stained them to detect cell structures and then digitised them with a high-resolution scanner so that the 3D brain model could be reconstructed. It took around 1,000 hours to collect the data.

The fine-grained anatomical resolution should give scientists insights into the neurobiological basis of cognition, language, emotions and other brain processes.

"The (researchers) pushed the limits of current technology," said Peter Stern, editor of the journal Science where the work was peer-reviewed and published on Thursday.