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Young meth users at risk of increased brain degeneration Young adults who use methamphetamine may be more vulnerable to age-related brain degeneration when they grow older, according to new research.   The study examines the theory that methamphetamine puts young users at risk of developing deficits later in life (similar to Parkinson’s disease) in individuals with depletion of glial derived neurotrophic factor (GDNF). This protein protects and repairs dopamine in areas of the brain related to movement control. Loss of nerve cells that produce  dopamine is a major factor associated with Parkinson’s disease. Those who have a lowlevel of the protein are considered more susceptible to age-related brain degeneration as a result of methamphetamine use.   “Methamphetamine intoxication in any young adult may have deleterious consequences later in life, although they may not be apparent until many decades after the exposure,” said Jacqueline McGinty, Ph.D., MUSC departments of Neurosciences and Psychiatry & Behavioral Sciences professor. “These studies speak directly to the possibility of long-term public health consequences resulting from the current epidemic of methamphetamine abuse among young adults.”   In the work, published Aug. 15 in The Journal of Neuroscience, McGinty and her colleagues examined the role of GDNF in mice. At 2.5 months of age, the equivalent of adolescence in humans, mice with a partial GDNF gene deletion were compared to mice without the gene deletion; both were given either methamphetamine or saline injections four times during an eight-hour period. McGinty’s team discovered that the effects of this methamphetamine binge were exacerbated in the mice with the GDNF deletion. In addition,  at 12 months, the GDNF-depleted mice moved significantly less than genetically normal mice treated with methamphetamine.   Future studies might involve identifying the reasons for increased vulnerability to methamphetamine in GDNF-depleted mice in order to help minimize the harm methamphetamine causes to the brain.   “The emergence of behavioral deficits in animals months after methampheta-mine discontinuation may be relevant to human methamphetamine abusers,” said Nora Volkow, M.D., director of the National Institute for Drug Abuse. “It suggests that even though their current use may not result in deficits, as they age these deficits will become manifest.” Volkow did not participate in the study.   The work was supported by the U.S. Army, a National Institutes of Health program project grant and the MUSC Center on Aging.     Friday, Aug. 31, 2007 Catalyst Online is published weekly, updated as needed and improved from time to time by the MUSC Office of Public Relations for the faculty, employees and students of the Medical University of South Carolina. Catalyst Online editor, Kim Draughn, can be reached at 792-4107 or by email, catalyst@musc.edu. Editorial copy can be submitted to Catalyst Online and to The Catalyst in print by fax, 792-6723, or by email to catalyst@musc.edu. To place an ad in The Catalyst hardcopy, call Island Publications at 849-1778, ext. 201.