Imaging Levodopa-Stimulated Striatal Dopamine Release

Grant Type
Grant Year
Institution Location
Institution Organization Name
Washington University
Investigators Name
Black, Kevin, MD

Medicines that block the action of the brain messenger dopamine can effectively treat tics in people with Tourette Syndrome (TS). Intriguingly, increasing evidence suggests that boosting dopamine function can also reduce tics. In a recent study, raising dopamine production appeared to correct abnormal brain activation in some people with TS. These findings suggest two possibilities: does the brain control dopamine production abnormally in TS? Or is dopamine production normal in TS, implying that the abnormality is in the brain circuits that dopamine affects? We can address these questions directly using a positron emission tomography (PET) scanner and a dopamine system PET marker called [11C]raclopride. This marker binds to certain parts of the brain just like dopamine does, but when the brain produces its own dopamine, the [11C]raclopride is released. Since the PET scanner can “detect” the amount of [11C]raclopride, we can deduce how much dopamine the brain has released. In this study we will compare measurements between people with TS and appropriate control subjects, before and after the administration of a standard dose of levodopa which is an amino acid that the brain produces as the penultimate step in making dopamine. These preliminary data will be used to support an NIH Kevin J. Black, M.D. Washington University School of Medicine, St. Louis, Missouri Award: $74,000 (Year 2) This Award is Supported by a Generous Donation from Randi Zemsky Tourette Association of America Inc. – Research Grant Award 2005-2006