High doses of alcohol during adolescence may continue to affect the brain even after drinking stops, leading to structural changes in the brain and memory deficits, says a significant study.
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 fibres that accelerates the transmission of electrical signals between neurons.
Animals that were the heaviest drinkers also performed worse on a memory test later in adulthood.
"Alcohol drinking early in adolescence causes lasting myelin deficits in the prefrontal cortex, an area of the brain that is vital to reasoning and decision-making," said Heather Richardson, PhD, from University of Massachusetts, Amherst.
In this study, Richardson and colleagues compared myelin in the prefrontal cortex 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 team examined the alcohol-exposed animals several months later, they found that the animals continued to display reduced myelin levels as adults.
This suggests that exposure to high doses of alcohol during adolescence could exert lingering, if not permanent, damage to selective brain fibres.
According to the World Health Organisation (WHO), a growing number of adolescents and young adults around the world engage in binge drinking - the consumption of four (five for men) or more drinks over approximately two hours.
The study was published in the Journal of Neuroscience.
