Underage drinking is very common along with binge drinking, especially on college campuses, but for minors consuming alcohol the biggest concern might not be getting caught. Everyone who participates in underage drinking knows the risks that come with it: getting in trouble with the law, with your parents, or with your friends. But we may be ignoring one of the greatest, the long-term detrimental effects of teenage alcohol consumption. During adolescence the human brain is not yet fully developed and particularly susceptible to external influences, in particular drugs and alcohol. A study by Wanette Vargas et al. used rat models to show that adolescence drinking can have serious effects on your brain and subsequent performance.
Researchers examined the causal effect of alcohol consumption in adolescence and adulthood on the medial prefrontal cortex and corpus callosum. The prefrontal cortex is associated with high-level brain function including personality, decision making, and social behavior. It is largely involved in inhibiting inappropriate behavior. The medial prefrontal cortex is also involved in working memory, the cursory storage of information being actively used. It has connections to the corpus callosum, a structure that connects the left and right hemispheres of the brain, and allows the two halves to communicate and coordinate with each other.
To model binge drinking, adolescent rats were given access to self-administered sweetened alcohol. In adulthood some of these rats, along with controls, were given alcohol vapor to model alcoholism. Looking at the brains of these rats, researchers found several striking differences between rats that were binge drinkers or alcoholics and control groups. They found that adolescent drinking reduced the amount of white matter in the medial prefrontal cortex. Specifically, they found a reduction in the density of myelin in this area. Myelin is a material that coats the outside of neurons and increases the speed at which they communicate.
Perhaps the most startling of their findings was that this myelin degradation persisted into adulthood. The lost of myelin can lead to decreased communication between neurons and even this loss of signal. To see the effect of the degradation Vargas and colleagues examined the performance of these rats, both in adolescence and in adulthood, in a T-maze. This maze is meant to test memory and learning. They found that adolescence rats that underwent binge drinking performed significantly worse in the maze, suggesting that binge drinking during adolescence can lead to memory deficits in adulthood.
The corpus callosum was degraded in both adolescence binge drinking rats and adult alcoholism rats, specifically in the regions connecting to the front of the brain. Strangely both groups exhibited similar levels of corpus callosum degradation. This result is particularly astonishing because the adolescent binge-drinking rats consumed much less alcohol with less repeated exposure than the adult alcoholic rats. This indicates the adolescence brain is indeed very susceptible to alcohol. The corpus callosum damage was correlated to increased relapse-like drinking behavior seen in these rats. In addition to relapse drinking, loss of the corpus callosum is linked to depression, addiction, and several other serious conditions.
It is necessary to note that this impact of alcohol was observed in rats and while some of these results have been recorded in humans, it is possible that alcohol may not affect humans in the same way or to the same magnitude. Additionally, Vargas and colleagues admit that effects observed may not be causal. However, even with these considerations the effect of teenage drinking, especially binge drinking, should not be taken lightly as it may have devastating long-term effects on brain function leading to memory problems and even a greater chance of developing alcoholism in adulthood.
Vargas WM, Bengston L, Gilpin NW, Whitcomb BW, and Richardson HN. (2014). Alcohol Binge Drinking during Adolescence or Dependence during Adulthood Reduces Prefrontal Myelin in Male Rats. The Journal of Neuroscience. 34: 14777-14782