Public Release: 

Precise technique tracks dopamine in the brain

New sensor could reveal the neurotransmitter's role in learning and habit formation

Massachusetts Institute of Technology



"Nobody has really measured neurotransmitter behavior at this spatial scale and timescale. Having a tool like this will allow us to explore potentially any neurotransmitter-related disease," says Michael Cima, the David H. Koch Professor of Engineering in the Department of Materials Science and Engineering, a member of MIT's Koch Institute for Integrative Cancer Research, and the senior author of the study.

Furthermore, because the array is so tiny, it has the potential to eventually be adapted for use in humans, to monitor whether therapies aimed at boosting dopamine levels are succeeding. Many human brain disorders, most notably Parkinson's disease, are linked to dysregulation of dopamine.

"Right now deep brain stimulation is being used to treat Parkinson's disease, and we assume that that stimulation is somehow resupplying the brain with dopamine, but no one's really measured that," says Helen Schwerdt, a Koch Institute postdoc and the lead author of the paper, which appears in the journal Lab on a Chip.

Studying the striatum

For this project, Cima's lab teamed up with David H. Koch Institute Professor Robert Langer, who has a long history of drug delivery research, and Institute Professor Ann Graybiel, who has been studying dopamine's role in the brain for decades with a particular focus on a brain region called the striatum. Dopamine-producing cells within the striatum are critical for habit formation and reward-reinforced learning.







How learning happens


"We and other people have struggled with getting good long-term readings," says Graybiel, who is a member of MIT's McGovern Institute for Brain Research. "We need to be able to find out what happens to dopamine in mouse models of brain disorders, for example, or what happens to dopamine when animals learn something."


This study is part of a larger collaboration between Cima's and Graybiel's labs that also includes efforts to develop injectable drug-delivery devices to treat brain disorders.

"What links all these studies together is we're trying to find a way to chemically interface with the brain," Schwerdt says. "If we can communicate chemically with the brain, it makes our treatment or our measurement a lot more focused and selective, and we can better understand what's going on."



