NYTimes | The visible brain has arrived — the consistency of Jell-O, as
transparent and colorful as a child’s model, but vastly more useful.
Scientists at Stanford University
reported on Wednesday that they have made a whole mouse brain, and part
of a human brain, transparent so that networks of neurons that receive
and send information can be highlighted in stunning color and viewed in
all their three-dimensional complexity without slicing up the organ.
Even more important, experts say, is that unlike earlier methods for
making the tissue of brains and other organs transparent, the new
process, called Clarity by its inventors, preserves the biochemistry of
the brain so well that researchers can test it over and over again with
chemicals that highlight specific structures and provide clues to past
activity. The researchers say this process may help uncover the physical
underpinnings of devastating mental disorders like schizophrenia, autism, post-traumatic stress disorder and others.
The work, reported on Wednesday in the journal Nature,
is not part of the Obama administration’s recently announced initiative
to probe the secrets of the brain, although the senior author on the
paper, Dr. Karl Deisseroth at Stanford, was one of those involved in
creating the initiative and is involved in planning its future.
Dr. Thomas Insel, director of the National Institute of Mental Health,
which provided some of the financing for the research, described the new
work as helping to build an anatomical “foundation” for the Obama
initiative, which is meant to look at activity in the brain.
Dr. Insel added that the technique works in a human brain that has been
in formalin, a preservative, for years, which means that long-saved
human brains may be studied. “Frankly,” he said, “that is spectacular.”
Kwanghun Chung, the primary author on the paper, and Dr. Deisseroth
worked with a team at Stanford for years to get the technique right. Dr.
Deisseroth, known for developing another powerful technique, called
optogenetics, that allows the use of light to switch specific brain
activity on and off, said Clarity could have a broader impact than
optogenetics. “It’s really one of the most exciting things we’ve done,”
he said, with potential applications in neuroscience and beyond.
“I think it’s great,” said Dr. Clay Reid, a senior investigator at the
Allen Institute for Brain Science in Seattle, who was not involved in
the work. “One of the very difficult challenges has been making the
brain, which is opaque, clear enough so that you can see deep into it.”
This technique, he said, makes brains “extremely clear” and preserves
most of the brain chemistry. “It has it all,” he said. Fist tap Rembom.
