The prefrontal cortex has been associated with higher cognitive function. It controls several cognitive processes that result in planning, goal-oriented behavior, impulsivity, and inhibitory control. The prefrontal cortex is one of the last areas of the brain to mature as this happens during adolescence. During this time, there are changes in gray matter density, increase in myelination, pruning of excitatory synapses and proliferation of inhibitory circuits. During this key period, adolescents are exposed to many factors that could affect the proper development of the prefrontal cortex and other regions of the brain; therefore, causing long-term effects in behavior. One of the elements that may be responsible for these long-term consequences is substance abuse.
In the paper “Consequences of Adolescent Ethanol Consumption on Risk Preference and Orbitofrontal Cortex Encoding of Reward” rodents are used to test the effects of alcohol consumption during the corresponding adolescent stage. In order to do this, the rodents were divided into three different categories: control, EtOH-high, and EtOH-low, based on their levels of alcohol consumption throughout the experiment. In the experiment, there was a variability in the amount of alcohol intake accounting for the difference between the EtOH-high, and EtOH-low groups. The differences between the groups were assessed by comparing the “animals’ risk preference and orbitofrontal cortex responses to probabilistic rewards following voluntary consumption of alcohol during adolescence”. Adults that did not consume alcohol in adolescence were able to adjust their preferences for a risky option according to probability while adults that consumed more alcohol in adolescence showed poorer discrimination of probabilistic rewards. Electrophysiological recordings showed that responses in the medial prefrontal cortex at the time of performing the risky behavior were modulated by adolescent intermittent resulting in a less pronounced response compared to control animals. Responses in the orbitofrontal cortex were also modulated by alcohol consumption. Both results indicated a change that affected the animals’ ability to compare risk and probability leading to more risky behavior as a result of ethanol consumption.
Another study from the University of Eastern Finland also showed that heavy alcohol consumption during adolescence causes significant changes to the brain. This study used magnetic resonance imaging in both healthy adults that were heavy drinkers during adolescence and healthy adults that were light drinkers (control). Imaging of the brain showed that “Among the heavy-drinking participants, grey matter volume was decreased in the anterior cingulate cortex bilaterally as well as in the right insula” demonstrating observable cortical thinning. It is believed by the investigator that alcohol disrupts the maturation process in the brain that is happening during adolescence. The damage caused in these areas is thought to play a key role in the development of substance use later in life.
As demonstrated by both studies, adolescence is a key period for the proper development of the brain Alcohol consumption during adolescence disrupts the maturation of several areas in the brain and creates long-term consequences. It does not only lead to an increase in risky behavior but it also creates a disposition for later development of substance use disorder.
Works Cited
Heavy alcohol use changes adolescents' brains. (2016, December 08). Retrieved from https://www.sciencedaily.com/releases/2016/12/161208085850.htm
Mcmurray, M. S., Amodeo, L. R., & Roitman, J. D. (2015). Consequences of Adolescent Ethanol Consumption on Risk Preference and Orbitofrontal Cortex Encoding of Reward. Neuropsychopharmacology,41(5), 1366-1375. doi:10.1038/npp.2015.288
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