Alcohol gains access to appetitive learning through adolescent heavy drinking

Area of Science:

• Neuroscience
• Behavioral Science
• Addiction Research

Background:

• Adolescent heavy alcohol drinking elevates the risk for adult alcohol use disorders.
• The underlying mechanisms linking adolescent drinking to adult alcohol use disorders remain poorly understood.
• Adolescent alcohol exposure may alter the brain's reward pathways, influencing alcohol's perceived value.

Purpose of the Study:

• To investigate how adolescent heavy alcohol drinking influences the aversive or appetitive properties of alcohol in adulthood.
• To determine if adolescent alcohol exposure shifts alcohol's association from an aversive to an appetitive learning signal.
• To examine the impact on the value of alcohol-predictive cues.

Main Methods:

• Genetically heterogeneous male Long Evans rats were given voluntary access to alcohol or water during adolescence.
• Rats were categorized into moderate and heavy alcohol drinkers based on consumption.
• Flavor learning procedures were used to assess the appetitive or aversive properties of alcohol and sugar in adulthood after a period of abstinence.

Main Results:

• In alcohol-naïve and adolescent moderate drinkers, alcohol was learned as aversive, while sugar was appetitive.
• In adult rats with a history of adolescent heavy alcohol drinking, both alcohol and sugar were learned as appetitive.
• This indicates that adolescent heavy drinking facilitates alcohol's access to appetitive learning pathways.

Conclusions:

• Adolescent heavy alcohol drinking fundamentally alters the neurobehavioral processing of alcohol, shifting its learned properties from aversive to appetitive.
• This shift may contribute to the continued use and potential for alcohol use disorders in adulthood by making alcohol and its cues more rewarding.
• Findings highlight the critical developmental window of adolescence in shaping long-term alcohol-related behaviors and risks.