"The findings strongly suggest that binge alcohol exposure during adolescence alters the neurobiology of the brain in a manner that can be long lasting. These long-lasting changes highlight adolescence as a critical period when alcohol abuse can produce changes in the brain. These changes might represent a long-term state that leads to alcohol abuse."
The present research supports the notion that chronic binge ethanol exposure produces changes in rat brain. The research also is the first to identify genetic and steroid changes that are directly associated with tolerance to the cognitive impairing effects of ethanol.
In the study, 16 male rats were treated with 5.0 grams/kilogram of ethanol every 48 hours from postnatal day 30 to postnatal day 50, the time period corresponding to adolescence in rats. Hippocampi were then collected on postnatal day 51 or postnatal day 65 and genetic changes were then measured.
Chronic binge alcohol exposure during adolescence was found to alter the expression pattern of several genes including genes that are known to change during ethanol tolerance. Changes in mRNA levels were then verified by similar changes in protein levels in the hippocampus in a unique group of 24 animals. Finally, changes in the function of the brain that might underlie tolerance were examined by recording the activity of single brain neurons in the hippocampus of 19 additional rats. It was revealed that chronic binge alcohol exposure during adolescences produced alcohol tolerance in single neurons of the brain. Finally, it was discovered that chronic binge alcohol exposure during adolescence produces tolerance to alcohol increases in brain steroid levels.
Future studies must identify whether such changes last thr
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Contact: Dawn McCoy
dawn@sfn.org
202-462-6688
Society for Neuroscience
8-Nov-2003