When you bring a piece of chocolate to your mouth, your brain responds by giving you a flood of dopamine, a chemical associated with pleasure — but that's not dopamine's only function.
Local researchers think it may also play an important role in how the brain processes sound and communications.
"Dopamine's involved in a whole bunch of different processes," said Christine Portfors, head of Washington State University Vancouver's Hearing and Communications Lab. "People who lose it, especially those with Parkinson's disease, tend to lose speech and some of their ability to process sounds. So we want to study dopamine in mice to see how it affects those abilities."
Portfors got a $1.6 million, five-year grant from the National Institutes of Health in January to study how the chemical affects hearing and speech. She'll collaborate with David Perkel, a professor of biology at the University of Washington in Seattle, on the project.
In the study, Portfors, also a WSUV associate professor of biological sciences, will alter the brain chemistry of mice by adding and blocking dopamine to see how different levels change the animals' behavior.
Male mice communicate to females by singing to them, and the researchers can record those sounds and play them back to females to see how they respond when they have different levels of dopamine in their brains.
This is the first collaborative project to explore how dopamine affects the brain cells, synapses and neural circuits that are involved in hearing and speech.
"Our combined expertise means we can learn more about the role dopamine plays in our hearing," Portfors said of working with Perkel.
Robert C. Bates, director of research and graduate education at WSUV, said this sort of award is an important part of President Obama's emphasis on brain research. It also speaks well of the university that it can draw this caliber of study, he said.
"We have some leading faculty doing research in important areas in human health," Bates said. "To get funding for that is a real confirmation for the university and for our researchers."
Dopamine is well known to be associated with the brain's pleasure centers, but there's a lot of other things it does that we don't yet understand, Portfors said.
"We know where the neurons in the brain make it, but we don't know how dopamine gets into the auditory system," Portfors said. "We also know it affects how your neurons fire."
The chemical is also associated with addiction, creating a craving response when addicts think of a particular drug.
"It does a whole bunch of things that nobody really knows," Portfors said. "It also seems to be part of (how the body controls) movement."
Parkinson's, a disease that can cause tremors, balance problems and issues with communication, is a primary focus of the study, but the research could also apply to other dopamine-associated disorders, she said.
Besides paying for equipment and animals, the grant will allow Portfors to hire a full-time researcher, fund two graduate students and pay two undergraduate students for summer work.
"It's great that we can pay people to stay in our area through this," Portfors said.
The work will also give students valuable experience that will help them get jobs in the future, she said.
"Not only is this funding important for human health, it is important for the local economy," Portfors said.