The findings raise other questions such as whether nicotinic drugs could be used as treatments for ADHD, whether the effects we found are specific to people with ADHD, and how the gender of the subject might affect these findings, Potter says. Future studies are aimed at beginning to answer these questions.
In a study of alcohol, scientists found that binge alcohol exposure during adolescence in rats caused long-lasting tolerance to alcohol, and represent the first investigations into the long-term brain effects of chronic binge alcohol exposure during this age. The study was conducted by Douglas Matthews, PhD, of the University of Memphis.
Tolerance, a reduced effect of a drug following previous exposure to the drug, is a hallmark of chronic ethanol exposure in adults. Specifically, alcohol tolerance results from the loss of ethanol responses in individual brain neurons and the loss of the ability of ethanol to elevate brain steroid levels. In addition, chronic binge alcohol exposure altered specific GABA-A receptor and other brain protein levels, and these alterations persisted following an extended alcohol free period.
Chronic alcohol abuse during adolescence produces profound neurobiological changes that might last until adulthood. Adolescence, a critical period of neural development, is often marked by high levels of alcohol abuse in humans. For example, the 2000 National Household Study on Drug Abuse reported that 16.4 percent of adolescents used alcohol in the month prior to the survey, while 10.4 percent reported binge drinking (consumption of 5 or more drinks on one occasion), and 2.6 percent report heavy alcohol use (5 or more drinks on 5 or more occasions). Binge and heavy drinking peak at age 21 with 45.2 percent reporting binging, and 16.7 percent reporting heavy drinking.
While it has been known for several years that alcohol drinking during adolescence predicts future alcohol abuse, the underlying mechanis
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Contact: Dawn McCoy
dawn@sfn.org
202-462-6688
Society for Neuroscience
8-Nov-2003