Ethanol Consumption in Adolescents

Throughout adolescence, neurodevelopment of the prefrontal cortex is crucial to future behavior in reward processing and decision making. Consuming alcohol during this time could have extremely negative consequences on future behavior, as the cortico-striatal circuitry is maturing. Long-term effects such as neurodegeneration and depletion of neurogenesis created by disruptions to development of the prefrontal cortex can emerge as well. As people tend to start drinking at a young age, it creates an impulsivity that continues into adulthood, with repercussions such as disrupted cortical processing.

In the article, “Consequences of Adolescent Ethanol Consumption on Risk Preference and Orbitofrontal Cortex Encoding of Reward,” the effect of alcohol consumption on cortical encoding for different sized rewards and probabilities was examined. The orbitofrontal segment of the prefrontal cortex (OFC) functions highly in decision making. With consumption of alcohol in young adults, perturbations of the OFC effect reward expectations. During his talk, Jamie Donahey Roitman explained the focus of the study was to show an association between a greater change in activity of OFC from reward responses in situations with risk and a greater inclination for the option of risk. This study was performed by categorizing rats into three different consumption groups; Control, EtOH-low, and EtOH-high. Those in the EtOH-high group had attained blood ethanol levels (BELs) at the level of binge drinking, while EtOH-low was notably lower. Behavioral testing was conducted once the animals reached adulthood to record risk preference. Electrophysiological recordings of activity in the OFC were taken in neural spike data to mark the units of time of trial events. The results showed large risky rewards had a greater preference than small but certain rewards. Therefore, it was concluded that changes in cortical function from consumption of alcohol in adolescents showed increase in risk preference though adulthood.

The review article, “The Burden of Binge and Heavy Drinking on the Brain: Effects on Adolescent and Young Adult Neural Structure and Function,” by Anita Cservenka, examined the effects of large consumption of alcohol through adolescence on neural development and function. Using functional magnetic resonance imaging (fMRI), they examined the brain structures of adolescents who were heavy drinkers. Thickness and volume of structures such as gray and white matter as well as cortex and cerebellar regions were evaluated. They used fMRI’s to look at response inhibition, working memory, verbal learning and memory, decision making and reward processing, alcohol cue reactivity, and socio-cognitive/socio-emotional processing. The results showed a thinning in the thickness of the prefrontal cortex, cerebellar regions, and the development of white matter. Altered structures of the brain result from binge drinking during adolescence as well as an increased risk of alcohol use disorder in adulthood.

Both studies examined the effects of alcohol consumption on neurodevelopment in adolescents, and showed similar results of altered neural structure and cortical function. Dr. Roitman looked more at the OFC and risk preference of EtOH-high adolescents through adulthood by using electrophysiological recordings. Dr. Cservenka examined the overall brain structure and function from heavy drinking using fMRI’s. Dr. Cservenka had mixed findings while looking at risky decision making, but claimed it could be due to variation in the study. Importantly, both concluded with showing the negative affects alcohol has on maturing prefrontal cortexes during adolescence.

Citations

Mcmurray, Matthew Stephen, et al. “Consequences of Adolescent Ethanol Consumption on Risk Preference and Orbitofrontal Cortex Encoding of Reward.” Neuropsychopharmacology, vol. 41, no. 5, 2015, pp. 1366-1375., doi:10.1038/npp.2015.288.

Cservenka A and Brumback T (2017) The Burden of Binge and Heavy Drinking on the Brain: Effects on Adolescent and Young Adult Neural Structure and Function. Front. Psychol. 8:1111. doi: 10.3389/fpsyg.2017.01111