A diffusion spectrum image shows brain wiring in a healthy human adult. The threadlike structures are nerve bundles, each containing hundreds of thousands of nerve fibers. (Image: NIH)
A diffusion spectrum image shows brain wiring in a healthy human adult. The threadlike structures are nerve bundles, each containing hundreds of thousands of nerve fibers. (Image: NIH)

Two UA Scientists Give Extra Thought to the Brain

With funding from President Barack Obama's BRAIN initiative, two researchers are developing better ways of measuring how neurons communicate with each other.
Dec. 1, 2014

Learning, moving, making decisions — these are all simple things we do on a daily basis without giving them much thought.

However, these processes are mediated by complex systems of circuitry in the brain relaying vast amounts of information thousands of times per second. Few people realize that this organ in the space between our ears is one of the most mysterious and least understood places in the universe.

Thanks to advances in neuroscience, researchers are beginning to peer into the brain and study the intricacies of how it functions. In April 2013, President Barack Obama announced the BRAIN (Brain Research through Advancing Innovative Neurotechnologies) initiative, which provides more than $300 million to fund research seeking to revolutionize our understanding of the brain.

Earlier this year, University of Arizona scientists Stephen Cowen and Michael Heien received a two-year, $300,000 grant from the National Science Foundation's Early Concept Grants for Exploratory Research program, a part of the BRAIN initiative. Cowen and Heien are developing technology that will allow scientists to better measure how populations of brain cells are able to communicate with each other in real time in waking and behaving animals.

"We are interested in how groups of brain cells work together to make decisions, navigate, remember and learn," said Cowen, assistant professor in the Department of Psychology. "Studying the interactions between these groups is fundamental to these processes."

Brain cells, called neurons, are able to relay information through a complex system of chemical and electrical signaling. Scientists have been making chemical and electrical measurements of populations of neurons separately since the 1950s, but no one has yet figured out how to measure the two simultaneously.

The ability to rapidly capture the chemical and electrical signals relayed through the brain is critical to understanding its function. Cowen and Heien are developing a technology that can do just this.

"Thoughts occur on a millisecond timescale," said Heien, assistant professor of analytical chemistry in the Department of Chemistry and Biochemistry. "We need to be able to take fast measurements of small populations of neurons to understand cognition."

Cowen specializes in taking electrical recordings from populations of neurons in rats as they exert effort and make decisions; Heien studies chemical signaling between neurons in culture. A shared desire to unite these approaches brought about collaboration between the two.

Specifically, the new technology focuses on the measurement of dopamine, a neurotransmitter involved in learning, reward and attention, as well as many neurological disorders.

Currently, Cowen's research group is studying decision-making and learning behaviors in rats. The rats are trained to run on a maze where they are given the option of entering one of two doors. If the rat chooses the right door, it receives a reward. The door that provides the reward changes periodically, which tests the rat's ability to learn. All the while, electrical activity and dopamine signaling are monitored to determine what the brain is doing during these tasks.

"Dopamine is not only important in normal function, it also has a critical role in disorders like Parkinson's disease and drug addiction," Cowen explained. "Using this approach can tell us a lot about the way dopamine affects the connectivity of neurons in the brain."

At the moment, acquiring high-resolution measurements of activity across brain regions in both animals and humans is difficult, and more innovative methods are needed. The goal of the EAGER program is to promote high-risk, high-reward research leading to new technologies that can improve the study of brain function. According to Cowen and Heien, this is key in furthering our understanding.

"Oftentimes, scientific breakthroughs are the direct result of breakthrough technologies," Heien said.

Cowen and Heien emphasized that while they're currently focusing on the basic science, they ultimately want to see the technology scaled up and commercialized.

"This technology provides a major opportunity for other researchers asking interesting questions about the brain," Cowen said. "We want to spread this to the rest of the scientific community."

Although developing the technology to measure these brain circuits is notoriously difficult, Cowen and Heien explained that this shouldn't be a deterrent.

"Galileo said, 'Measure what can be measured, and make measurable what cannot be measured,'" Heien said. "That's exactly what we're doing here."