To see it, one has to see through it! In its natural state, the brain and the rest of the body are full of lipids, which are opaque. In order to view 3D images of the brain as a whole intact organ, it has to become see-through. To accomplish this, the lipids need to be extracted, but if they are removed without some sort of supporting structure, the brain will collapse in on itself, destroying is anatomical integrity.
Enter Karl Deisseroth, M.D., Ph.D., a NARSAD grant recipient from Brain & Behavior Research Foundation. He is also a member of the BRAIN initiative established by President Obama in April 2013. His team at Stanford designed a process called “CLARITY” which, through chemical engineering, constructs a shell around the lipids using hydrogel. Once this shell of clear gel is created, the lipids can be extracted, leaving the shell intake. All the axons, dendrites, neurons, nucleic acids, proteins, etc. are intact and in their correct place. Currently, this process has been done primarily on postmortem mouse brains and preserved human brain slices.
Before CLARITY, the technology didn’t exist to view the brain as a whole intact organ. To create a 3-D image, thousands of very thin sliced images are taken and then carefully put back together.
Dr. Deisseroth says, “Studying intact systems with this sort of molecular resolution and global scope—to be able to see the fine detail and the big picture at the same time—has been a major unmet goal in biology, and a goal that CLARITY begins to address,” Deisseroth also stated that technology will need to be developed to decipher the massive amounts of data that are created with this 3-D technology.
The key advantage to the CLARITY process is that florescent antibodies can be introduced to the brain because the hydrogel is permeable. This allows researchers to study relationships between parts of the brain that has not been done before. Once a segment of research is complete, the antibodies can be flushed out of the brain, and this process can be repeated several times.
This is monumental in the field of neuroscience.
“If CLARITY is a predictor, the next few years could be a period of rapid new insights into brain structure and function,” says Dr. Tom Insel, Director of the National Institute of Mental Health. “One can barely begin to imagine how tools like CLARITY will change our concepts of how the brain works in health and disease.”
HIKE for Mental Health proudly supports the Brain & Behavior Research Foundation.