Dr. Karl Deisseroth.
Dr. Karl Deisseroth.

Last November, San Diego hosted over 30,000 scientists dedicated to the study of the human brain at Neuroscience 2013, the annual meeting of the Society for Neuroscience, and the largest of its kind in the world.

Along with the usual posters and exhibit hall, where BioSurplus had a booth, there were 15,000 presentations featuring new findings in the world of neuroscience.  Among those presentations was one from the lab of Dr. Karl Deisseroth of Stanford University.

In my ongoing search for information on cutting-edge technologies in science, I came across a recent article in the New York Times on Dr. Deiserroth.

The article tells the fascinating story of his contributions to the development of two breakthrough tools in brain study:  optogenetics, a technique in which light-sensitive proteins found in algae are inserted into neurons, allowing them to be turned on and off, and now CLARITY, a method by which whole brains are turned transparent, giving researchers a new way to examine brain structure in three dimensions.

 

Journey Into Psychiatry And Neuroscience

Karl Deiserroth didn’t always plan on becoming a scientist.  In fact, his first desire was to be a writer.  When he enrolled at Harvard for undergraduate studies,  he took creative writing classes, but eventually discovered a love of science.  He went on to earn a degree in biochemistry there in 1992.

After graduation, Deisseroth headed to Stanford to pursue a medical degree.  His goal was to become a neurosurgeon; the first clinical rotation he did was in brain surgery.  His second rotation, however, was in psychiatry and it was here that he found his calling.

This was his first experience talking to actual patients.  He witnessed their suffering firsthand and was moved to dedicate his life to the search for a cure for psychiatric disorders such as bipolar disorder, depression, autism and schizophrenia.

Deisseroth soon realized that scientists lacked the proper tools to study the brain effectively.  He modified the direction of his research at Stanford and joined the new bioengineering department, which had just been launched in 2002.  He earned a PhD in neuroscience in 1998, and received his degree in medicine in 2002; Dr. Deiserroth is now a professor of both psychiatry and bioengineering at the university.

 

Finding CLARITY

Dr. Kwanghun Chung.
Dr. Kwanghun Chung.

Dr. Deiserroth’s latest contribution to the neurosciences toolkit is called CLARITY.  Along with Dr. Kwanghun Chung, a former member of his lab who’s now at M.I.T., and other colleagues, Deiserroth has developed a method to render a non-living brain completely transparent, allowing it to be studied in 3D.

The technique combines elements of both chemical and bioengineering, and provides a way to avoid the necessity of disassembling the tissue to be studied.

A substance called hydrogel, which is primarily made of up water, is injected into the tissue.  This strengthens its physical structure, binding the components, including proteins, neurochemicals, DNA and RNA; the process is much like fossilization or petrification.

The lipids in the tissue, which are difficult to see under a microscope, are then washed away using a detergent called SDS, leaving it transparent.  The integrity of the structure is maintained down to the level of individual synapses.

One of Deiserroth’s primary interests is the study of the differences between healthy and diseased brains.  In a video produced for Stanford, he states that the abnormality in the brain of an individual suffering from a disorder such as autism “may relate to three-dimensional wiring or connectivity differences.” (Watch the CLARITY video on YouTube here).

The technique has already been used to further autism research.  Referring to a paper on CLARITY published by Kwanghun Chung, the journal Nature states in a recent article that:

 “…the researchers analyzed brain tissue from a seven-year-old boy who had autism spectrum disorder.  They found that neurons in his cortex had joined together in ladder-like patterns, rather than the branches seen in typical brains.  Animal models of autism-like conditions had hinted at this difference, but CLARITY made it possible to look for the irregularity in human brain samples.”  (Read the article in Nature)

CLARITY has the potential to make an impact on a wide swath of scientific inquiry, including cancer research, where scientists can use the technique to study the spatial arrangement and volumes of cancer stem cells.

And Deiserroth and Stanford are making the technology available to all researchers;  Stanford has applied for patents on certain aspects, but only to ensure that free access is maintained.

For his part, Dr. Karl Deiserroth will continue to develop the necessary tools and search for a cure for severe mental illness.  In spite of his incredibly busy schedule, he still sees patients to this day, allowing him to connect with the people his research will eventually benefit.

To read more about neuroscience and technology, read the following articles on our blog:

Remembering To Remember: New Findings On Patient H.M.

fMRI – Jack Belliveau And The First Image Of Human Brain Function