X-Message-Number: 13074 Date: Sun, 09 Jan 2000 19:25:19 -0500 From: Jan Coetzee <> Subject: Brain Drain Brain Drain David Nicholson 7 January 2000 Chemical changes in the brain that may underlie the cognitive deterioration associated with ageing have been pinpointed by researchers in the US. The team, a collaboration between the US Department of Energy s Brookhaven Laboratory, the State University of New York and the University of Pennsylvania, found that age is associated with a significant decline in dopamaine D2 receptors. These receptors are molecules that transmit signals known to affect pleasure and reward. According to the lead author of the study, Dr Nora Volkow, such age-related loss of dopamaine slows metabolism in regions of the brain that are related to cognition . She added that the study s findings may well be useful in developing interventions for age-related cognitive decline. Decrease in dopamaine with ageing has been corroborated by previous studies done by Volkow and others. They believe that there is a rate of six per cent of receptors lost with each decade of age, from 20 to 80 years. However, this new investigation led to the discovery that when dopamaine D2 receptors decreased, so did regional glucose metabolism in the areas of the brain known as the anterior cingulate gyrus. Functions such as problem solving, the ability to think abstractly, and the capacity to carry out multiple tasks are among those controlled by the anterior cingulate gyrus (the frontal region of the brain). It is also related to attention span, impulse control and mood. Decreased glucose metabolism therefore translates to decreased brain activity, or deterioration of brain function. However, the study also showed that while dopamaine declines with age in general, there is a correlation between dopamaine availability and brain metabolism even after removing age effects. This suggests that dopamine may influence brain metabolism regardless of age it is not always the case that dopamine will decline with age, and some younger people may have less dopamine than some older individuals. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=13074