Predicting alcohol consumption and reward sensitivity using responses for natural sucrose reward in non-food-restricted rats.

RATIONALE: While around 50% of the risk for developing Alcohol Use Disorder (AUD) has been determined to be genetic, examining predictors of addictive-like behavior and individual variance in models without a family history of addiction is also important. Impaired reward sensitivity and response to natural reward may play a role in an individual's propensity to develop alcohol addiction. Little research has been done on predictors of alcohol addiction without food or water deprivation to coax animals into addiction.

OBJECTIVES

This study seeks to examine psychological and behavioral predictors of alcohol addiction in non-food restricted rats and determine whether sucrose seeking, consumption, and reward sensitivity relates to later motivation and reward-sensitivity related functions for ethanol.

METHODS

This study examined the appetitive and consummatory behavior of female Wistar rats in self-administration tasks using sucrose and ethanol solutions and ad-libitum access to food and water. Varying time of access for sucrose was utilized to evaluate reward sensitivity analyzing inter-session and intra-session measures.

RESULTS

Operant sucrose consumption predicted both 15% and 30% ethanol consumption in the home cage during 30-min exposure. Animals expressed key differences in reward sensitivity between natural and drug reward including lack of reward discrimination for sucrose during consumption along with different profiles of responding for sucrose and ethanol during the anticipatory motivated actions.

CONCLUSIONS

Using more precise measures of natural reward sensitivity could provide key insight into vulnerability to develop substance use disorders.