RADIOTRACER CHEMISTRY TIP SHEET
Positron emission tomography (PET) opens a window on human health and behavior with its ability to visualize biochemical activity in the living body. The technique relies on short-lived, radioactive chemicals that emit bursts of energy as they decay. Scientists use these chemicals to harmlessly tag substances and trace their effect in the body through PET scan images. The following is a summary of one paper concerning radiotracer chemistry that will be presented in Dallas at the national meeting of the American Chemical Society, world's largest scientific society.
SEEING HOW THE BRAIN CHANGES DURING AGING
As we age, our brains lose valuable dopamine receptors, which help govern our motor and cognitive skills. Joanna S. Fowler, Ph.D. and colleague Nora D. Volkow, M.D., of Brookhaven National Laboratory report that multiple radiotracer chemicals are helping researchers to study more precisely how the dopamine system changes as we age. These radiotracers can also shed light on brain changes associated with such conditions as Parkinson's disease and smoking. Raclopride and d-threo methylphenidate are two substances taken up by different parts of the dopamine cell. By tagging each substance with the radiotracer carbon-11, researchers can observe the dopamine system in action with a PET scan. The Brookhaven team used these radiotracers to study persons ranging in age from 23 to 86. The researchers asked each person to perform motor and cognitive tests and then used the PET scan to "watch" how their dopamine systems worked. The older the person, the more poorly they performed the tests and the lower their level of dopamine activity. Fowler's gr
Contact: Nancy Blount
American Chemical Society