Heavy drinking during teenage years can lead to structural changes in the brain that can cause memory deficits which persist into adulthood, a new study reveals.
The study found that, even as adults, rats given daily access to alcohol during adolescence had reduced levels of myelin - the fatty coating on nerve fibers that accelerates the transmission of electrical signals between neurons.
These changes were observed in a brain region important in reasoning and decision-making. Animals that were the heaviest drinkers also performed worse on a memory test later in adulthood. The findings suggest that high doses of alcohol during adolescence may continue to affect the brain even after drinking stops. Further research is required to determine the applicability of these findings to humans.
In this study, Heather Richardson, PhD, her graduate student Wanette Vargas, BA, and colleagues at the University of Massachusetts, Amherst, compared myelin in the prefrontal cortex - an area of the brain that is vital to reasoning and decision-making - in young male rats given daily access to either sweetened alcohol or sweetened water for two weeks. Animals that drank alcohol as adolescents had reduced myelin levels in the prefrontal cortex compared with those that drank a similar amount of sweetened water.
When the researchers examined the alcohol-exposed animals several months later, they found that the animals continued to display reduced myelin levels as adults.
The study was published in The Journal of Neuroscience.