New Way to Gain a Clear View of the Brain

A group of Japanese neuroscientists based out of Riken Brain Science Institute in Wako, Japan has created a rather inexpensive mixture that turns the brain’s opaque, gray matter into a see-through, glassy matter. The chemical solution is patented under the name “Scale”, coming from the Japanese word for “transparent”, and is composed of urea, glycerol, and detergent. The chemical solution transforms the dead biological tissue in the brain into a translucent jelly. Once brain tissue has been soaked in the mixture, it makes it much easier for neuroscientists to see what is inside the brain.

The neuroscientists are hopeful to one day have the means to uncover the physical basis of personality, memory, and consciousness. A distant goal of the team is to be able to map the brain’s architecture. Researchers are working to build a “connectome”, or map, of a mouse brain because mouse brains are much less complex than human brains. However, constructing a “connectome” of the human brain is a far-off goal of researchers all over the world.

The current method to be able to view brain tissue under a microscope is to cut it into slices with thicknesses around that of a strand of human hair. Light then passes through the slices and they can be analyzed. Currently, Dr. Lichtman at Harvard University is working towards mapping out a map brain in this manner, but is nowhere close to being finished. This is because even a mouse brain requires the brain to be divided into around one hundred slices to be analyzed and in the slicing process, the brain can be distorted and small pieces of brain tissue can be lost. Using “Scale”, however, a mouse brain would not need to be sliced so thinly, but rather could be imaged in only three large pieces. “Scale” also clarifies the tissue without removing water, so the solution sustains genetically introduced cell labels, made from proteins in jellyfish and corals, that are used to differentiate one neuron from the next. Dr. Lichtman plans on starting to use “Scale” in his lab to improve the clarity of the brains with which he works.

Though “Scale” has yet to be used on human brains, the researchers hope that they will soon have the opportunity to once they are allowed to obtain a specimen. Dr. Miyawaki, a researcher on the team in Japan, expects that the solution will work just as well on human brains as it has on the mouse brains. The team also hopes to eventually discover a solution that can be used on living tissue, instead of solely on dead brain tissue.

“Scale” works much better on younger brains than older brains. The ultimate goal is to be able to use the mapping to compare brains of different ages and gain knowledge of organ development and how genetic differences affect development.

Source: http://www.nytimes.com/2011/10/11/health/11brain.html?_r=1&ref=health (Published on October 10, 2011)