Chemical-Dipped Transparent Brains Clear Up Mental Mysteries (Video)

What does the inside of a brain look like? How do large networks of neurons interconnect and function? Now, scientists may be able to clearly see what goes on inside a brain through the use of a chemical treatment that turns whole organs transparent. The new finding could lend a huge boost to the initiative to map a brain.

The new treatment is named CLARITY, and was devised by Karl Deisseroth and his team at Stanford University. It allows researchers to directly see into optically transparent brains, or thick blocks of brain tissue. Essentially, the treatment uses the detergent SDS, which strips away all lipids that normally block the passage of light. Although other treatments in the past used a similar technique, this one also infused the brain with acrylamide, which binds proteins, nucleic acids and other biomolecules. When the acrylamide is heated, it polarizes and forms a tissue-wide mesh that secures the molecules. This results in a brain-hydrogel hybrid that shows far less protein loss after lipid extraction than previous methods, according to Nature.

This technique wouldn't have been nearly as impressive without some kind of practical application, though. Researchers used CLARITY on mouse brains. With the treatment, they were able to view fluorescently labeled neurons throughout the brain. The detail and depth they were able to see was extraordinary.

"The work is spectacular. The results are unlike anything else in the field," said Van Wedeen, the lead investigator on the U.S. National Institutes of Health's Human Connectome Project, in an interview with Nature.

The new technique could potentially reveal important details that would complement data on large-scale neuronal pathways. This would allow researchers to better understand the brain and how it works, potentially leading to future treatments and breakthroughs in medicine.

The brain controls almost all functions of the body. It's the center of our nervous system, and is the source of our thoughts, emotions and memories. Yet surprisingly little is known about this organ, despite its importance to life. This is what partly prompted Obama to start his brain mapping project, which calls for billions of dollars to complete.

Yet CLARITY could provide an easier way for researchers to complete the project. It doesn't only have applications for mapping brains, though. The hydrogel-tissue hybrid formed by the technique is stiffer and more chemically stable than untreated tissue. The resulting brain could potentially turn delicate and rare disease specimens into reusable resources.

The findings are published in the journal Nature.

Want to see more? Check out the video about these transparent brains below, courtesy of Nature.