A new human brain model offers neurosurgeons and researchers a sophisticated and detailed three-dimensional tool, experts say.

Current reference brains just look at the visible parts of the brain based on simple drawings. Thursday's new online atlas, called BigBrain, shows brain anatomy in microscopic detail down to a level that's smaller than the size of a fine strand of hair — 50 times more detailed than before.

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Researchers use a special tool called a microtome to cut more than 7,400 sections from a brain preserved in paraffin wax into tiny slivers. (Courtesy Science)

"Our neuroanatomists and neurosurgeons in particular at the Montreal Neurological Institute are absolutely ecstatic," said senior author Alan Evans, a professor at the McGill University institute.

"The surgeons are all running in and out of the room right now trying to get at the data on the very, very big screen that we have on the wall," he told reporters.

Evans said the BigBrain offers a completely new level of insight into the brain’s organization. That's important for biologists who seek to relate structure and function of an organ as complex as the brain when probing normal human childhood development and how illnesses like Alzheimer's, Parkinson's or epilepsy occur.

"This allows us to further to examine the interaction between different brain regions, the organization of the brain and how it subserves behaviour," said Evans.

"So we've raised the level of insight orders of magnitude beyond what was possible at the turn of the 20th century."

To build the model, researchers took thin slices from a brain donated by a 65-year-old woman who is anonymous. She had no neurological or psychotic history, said Katrin Amunts, director of the Institute of Neuroscience and Medicine at Research Centre Jülich in Germany and a corresponding author of the study, published in the journal Science.

The 20-micrometre thick sections were stained and prepared in a lab, digitized with a high-resolution flatbed scanner and MRI then painstakingly reconstructed in multiple dimensions with advanced computing techniques for a data set that was on the order of 100,000 times larger than a typical MRI scan that in contrast doesn't offer more information after zooming in.

Atlas for neurosurgeons

The BigBrain offers the ability for doctors and researchers to plug in information such as patient MRI or PET scans.

When patients with Parkinson’s for instance have electrodes placed in their brains to control symptoms, surgeons rely on 2D drawings, said Amunts.

"In our BigBrain, this can serve as a new atlas for neurosurgery as well on a much higher spatial resolution and also with much more precision."

Dr. Mojgan Hodaie, a neurosurgeon at the Krembil Neuroscience Centre at University Health Network in Toronto, applauded the researchers for the meticulous work.

"Comparing this to the geography of the Earth, it would be like having one map that includes significant amount of detail of every street and neighborhood, and at the same time and with the same level of precision, tells us where the land masses are arranged and when do we get to the ocean," Hodaie said in an email to CBC News.

Hodaie said the atlas allows comparisons of the detailed arrangement of fine structures in the brain to understand questions such as where lobes begin and end with more accuracy. "The BigBrain atlas is free and available to all researchers. Allowing others to benefit from this work is in itself an immense value and a large service to the scientific community."

The BigBrain also provides a common basis for scientific discussions, said study co-author Prof. Karl Zilles from the Institute of Neuroscience and Medicine in Jülich, Germany.

In April, U.S. President Barack Obama announced a related North American project to record and map the interaction of brain cells. A similar billion Euro initiative is underway in Europe.

The atlas is available at https://bigbrain.loris.ca/main.php.