Neurological changes occur with the first drink of alcohol.
Young people abuse alcohol more than any other substance in the US, and American 12-20-year olds consume 11% of all alcohol nationally.
Statistics from the National Institute of Health (NIH) show that by the age of 15 years, about 35% of teens have consumed at least one alcoholic drink, rising to around 65% by the age of 18.
Although adolescents drink less frequently than adults, the practice of binge drinking means that when they do drink, they consume more. In fact, American youths consume more than 90% of their alcohol during binge-drinking sessions.
In 2014, 8.7 million young people between the ages of 12-20 years reported drinking more than "just a few sips" in the previous month.
The health and safety risks of underage drinking are enormous, and the practice poses a serious public health concern.
Attraction of alcohol lies in enduring cellular changes
Much of the attraction of alcohol, cocaine and other widely abused drugs lies in the perceived, euphoric "high" that they induce.
Research has associated this with activation neurons in the dopamine pathways that are related to goal-oriented and reward-based behaviors, and studies have shown that dopamine receptor D1 neurons play a key role in alcohol learning and reinforcement.
To understand more about long-lasting cell changes following the first experience with alcohol consumption, researchers from the University of California San Francisco (UCSF), led by Dr. Dorit Ron, looked into the neuronal behavior of mice.
They wanted to find out whether a single exposure to alcohol induces memory and behavioral changes that could promote future drinking.
The mice were subjected to a two-bottle drinking test for 24 hours, one bottle containing water and the other 20% alcohol. The next day, the scientists measured the neuron physiology for dopamine receptors D1 and D2 in the mice's brains.
Memory registers effects from the first exposure
In the mice that consumed alcohol, the scientists observed changes in the D1 neurons, compared with mice that only drank water.
The results indicate that the memory registers and stores the perceived benefits of alcohol from the very first time a person drinks.
Similar changes were observed after a single dose was given to mice that had not previously consumed alcohol, indicating that a first, and perhaps even a single, experience with alcohol can bring about permanent neurological changes.
The findings help to explain the neurological changes that accompany initial alcohol exposure and suggest that similar alterations underlie the reward-based learning associated with alcohol and other substance abuse.
The study also reveals pathways that could be targeted therapeutically by drugs to help patients who have problems with addiction.