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Thursday March 12 Dopamine Drop In Aging Brain Affects Movement NEW YORK (Reuters) -- Decreasing activity of the chemical messenger dopamine in the aging brain can be linked to declines in ability to move (motor function), according to a federally funded study. The results suggest that the development of therapies to boost dopamine activity in the brain could "...improve performance and quality of life for the elderly," according to a report published in the March issue of the American Journal of Psychiatry. Previous studies showed that a decline in dopamine activity in the brain is linked to cognitive (learning and memory) and motor problems in patients with Parkinson's disease. But that association has never been fully studied in normal subjects. In this study, researchers used various types of computer imaging to gauge the number of dopamine receptors in the brains of 30 volunteers, aged 24 to 86. They then administered tests that were designed to pick up deficiencies in motor and cognitive skills. The researchers found that dopamine activity declined with age. But they also found statistically significant correlations between dopamine activity and test performance even after age was taken into consideration. Those correlations were greatest for motor tasks but were also significant in tests of abstract thinking, mental flexibility, attention, and response time. The investigators concluded that drugs which enhance dopamine activity might be useful in improving motor and cognitive function in elderly patients. They also note that animal studies indicate that dietary restriction and exercise can help to slow the age-related decline in dopamine activity by preserving dopamine receptors in the brain -- that is, the sites on cell surfaces that the chemical binds to to produce its effects. In commenting on the study, editors of the journal characterized the results as "striking" since they were obtained in healthy volunteers, not in patients with symptomatic neurologic disorders. SOURCE: American Journal of Psychiatry (1998;155:344-349) 1 [log in to unmask] (Judith Richards)