Adolescent Drinking Linked to Risky Behavior in Adult Rats
A new study conducted in rats offers clues about how teen drinking alters brain chemistry, suggesting early alcohol use has long-term effects on decision-making.
"Early life experiences can alter the brain in the long term, with profound implications for behavior in adulthood," says Abigail Schindler, a postdoctoral fellow at the University of Washington who conducted the research. "This study points to the potential effects of alcohol on brain development in adolescence, a period of exploration when young adults are often experiencing alcohol for the first time."
The researchers gave alcohol-laced "Jell-O shots" to a group of rats 30-50 days of age, the equivalent of the teen years in humans. During this period, the rats were given access to the Jell-O shots 24 hours a day. Once the rats reached adulthood, they were given tests offering the opportunity to take a low risk to get a small treat or take a much higher risk to get a larger treat.
The rats exposed to alcohol during adolescence were consistently more inclined to take the high risk/high reward option, even when the safer option would have given them more treats overall. "This increase in maladaptive risk taking suggests that the alcohol exposure changed the way the animals make decisions," says Schindler.
To explain the phenomenon, the research team dug deeper into the rats' brain chemistry. They traced the effect to changes in dopamine, a brain chemical that contributes to the experience of reward, and to possible changes in GABA receptors, which can act as a brake system to keep dopamine in check.
Rats exposed to alcohol showed greater dopamine surges and changes in certain types of GABA receptors, suggesting that early alcohol exposure may take the breaks off of the dopamine system.
Source: Laboratory Equipment