Adolescence and Alcohol | wiaddictionresearch

Most people begin consuming alcohol as an adolescent, a unique period of behavioral, cognitive and brain development that increases the likelihood of experimentation and risk-taking behaviors. Due to ethical, moral and legal restraints against administering alcohol to those under the age of 21, animal models are often used to study the effect of alcohol exposure during adolescence.

Our laboratory has been leaders in the investigation of the effect of ethanol in adolescent animals compared to adult animals. Interesting, on most, but not all, measures, adolescent animals are less sensitive to the effects of alcohol than adult animals. For example, acute ethanol exposure in adolescent animals produce less of a motor impairment (termed ataxia), less of a global body impairment (termed aerial righting reflex), produces less sleep following a high dose ethanol exposure (termed sleep time or loss of righting reflex) and less ethanol-induced hypothermia compared to adult animals (see Figures below). From this constellation of data, we hypothesized that one reason adolescence consume larger amounts of ethanol than adults is because many of the behaviors that signal “I’ve had enough” are less effected by alcohol in adolescent subjects compared to adult subjects.

Animals administered acute ethanol show significantly less motor movement. However, the reduction in motor activity is significantly less in adolescent animals compared to adult animals demonstrating ethanol has less of an impact in adolescents compared to adults.

The neurobiological mechanisms that cause ethanol to often produce less of an effect in adolescent animals compared to adult animals is still under active investigation. One mechanism that our lab has identified is differential expression of a protein kinase called PKC. Protein kinases can facilitate the function of other proteins in the brain. Specifically we found that expression of PKC[gamma] is less in many regions of the adolescent brain compared to the adult brain potentially resulting in ethanol having less of an effect in the adolescent brain compared to the adult brain.

This representative Western blot shows higher

levels of PKC[gamma] expression in the adult PKC[gamma] bands

animals (those labeled OS) compared to the

adolescent animals (those labeled YS) Beta Actin bands