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Imaging Interactions between Alzheimer's disease and cerebrovascular disease SALSA Computer Based Therapy Imaging Brain Dopamine in Aging Imaging Gene Therapy Imaging Brain Amyloid in Vivo Alzheimer’s Disease Neuroimaging Initiative
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Alterations in neurotransmission are a well known association with aging. PET scanning provides the ability to measure neurotransmitter function in vivo. We are currently in the process of developing and refining ways to image different aspects of the brain dopamine system. Declines in brain dopamine are well known to occur in aging, and in their most extreme form are part of Parkinson’s disease. PET scanning permits measurement of numerous components of the dopamine system including dopamine transporters (DATs), dopamine metabolism, and dopamine receptors.
A major new project in the laboratory involves applying the tracer fluorometatyrosine (FMT) labeled with the positron emitter [18F] to study dopamine metabolism in aging. The image at right shows dopamine metabolism in vivo in a normal human subject. We plan to also investigate changes in DATs in the same individuals. Considerable evidence suggests that loss of dopamine function is associated with specific cognitive disturbances reflective of alterations in frontal lobe processing. Our interest is in linking changes in the dopamine system to cognitive and motor decline that occurs in normal aging. We also plan to relate changes in the brain’s dopamine system to alterations in patterns of functional activation seen with motor and cognitive tasks using fMRI. Over time, we expect to image a variety of other neurochemical systems, including the cholinergic system.
This project will also evaluate new and better ways of obtaining quantitative PET data from human subjects as quickly and noninvasively as possible. Some of the methodological advances we are employing include the use of imaging techniques to obviate the need to sample arterial blood, and techniques to lower the radiation exposure dose and imaging time for PET experiments. These techniques are being applied to studies of the dopamine system and glucose metabolism.
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