Leave it to the humble sea slug to help scientists unravel the mysteries of the human brain.
University of Illinois researchers have developed innovative tools that can probe the chemistry of the brain, a single neuron at a time. And one rich application has been with the sea slug Aplysia californica.
The sea slug's simple brain, which contains only 10,000 neurons, serves as an instructive model for examining basic operations in the human brain such as how neurons affect behavior and long-term memory, says Jonathan Sweedler, a professor of chemistry in LAS and director of the U. of I. Biotechnology Center.
In recent work, for example, Sweedler and his colleagues identified and mapped vitamin E in isolated neurons of the sea slug.
"To our surprise, we found that vitamin E was not distributed uniformly in the neuronal membrane," Sweedler says. "Instead, vitamin E was concentrated in the neuron right where it extends to connect with other neurons."
The concentration of vitamin E at neural connections could support theories that it plays a key role in the signals that one neuron sends to another.
"Understanding the chemistry that takes place within and between neurons, including small molecules like vitamin E, will no doubt lead to a better understanding of brain function in healthy and diseased brains," Sweedler says.
In addition to applying this technology to sea slugs, U. of I. researchers have used it with insect brains, which have 1 million neurons; and with mice brains, which have 100 million neurons.
"In most organ tissues of the body, adjacent cells do not have significant differences in their chemical contents," Sweedler points out. "In the brain, however, chemical differences between neurons are critical for their operation. The connections between cells are crucial for encoding information or controlling functions."
Working with Sweedler on this effort were research scientists Jinju Lee and Stanislav Rubakhin, postdoctoral research associate John Jurchen, and graduate student Eric Monroe. The U.S. Department of Energy and the National Institute of Drug Abuse provided funding.
