Contact: Heather Woolwine
843.792.7669
woolwinh@musc.edu
Aug. 15, 2007
MUSC study uses animal model to suggest meth triggers deficits later in life
Charleston -- Young adults who use methamphetamine may be more vulnerable to age-related brain degeneration when they grow older, according to new research released from the Medical University of South Carolina (MUSC).
The study examines the theory that methamphetamine puts young users at risk of developing deficits later in life (similar to Parkinsonís 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 Parkinsonís disease. Those who have a low level 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 their work, published August 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 over 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 methamphetamine discontinuation may be relevant to human methamphetamine abusers," says Nora Volkow, MD, 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.
The Journal of Neuroscience is published by the Society for Neuroscience, an organization of more than 36,500 basic scientists and clinicians who study the brain and nervous system.
About MUSC
Founded in 1824 in Charleston, The Medical University of South Carolina is the oldest medical school in the South. Today, MUSC continues the tradition of excellence in education, research, and patient care. MUSC educates and trains more than 3,000 students and residents, and has nearly 10,000 employees, including 1,300 faculty members. As the largest non-federal employer in Charleston, the university and its affiliates have collective annual budgets in excess of $1.3 billion. MUSC operates a 600-bed medical center, which includes a nationally recognized Children's Hospital and a leading Institute of Psychiatry. For more information on academic information or clinical services, visit www.musc.edu or www.muschealth.com.
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