Author: Kang Lai, Class of 2026

Alcohol Use Disorder (AUD) is a significant health problem, affecting more than 35 million Americans, diagnosed by the DSM-5. Despite such high prevalence, few medications exist that can effectively treat AUD. The neurobiological mechanisms influencing key reward-seeking areas such as the nucleus accumbens and ventral tegumental area of the brain still remain unclear to this day. A common feature of AUD is how individuals persist in drinking even when healthier options are available. In this study, researchers MF Lopez and HC Becker at the Charleston Alcohol Research Center aim to study alcohol seeking behavior when dependent mice are presented with an alternative reward such as sucrose.

Over the years, studies surrounding operant conditioning of alcohol administration, chronic alcohol procedures, and of alternate reward have shown mice exhibit a high preference for alcohol and model similar effects as AUDs. C57BL/6J mice, a strain known for voluntary alcohol consumption, are exposed to chronic intermittent ethanol (CIE) and force a swim stress test (FSS) to demonstrate alcohol-biased choice behavior in mice. Mice are placed in groups receiving CIE, CIE + FSS, and control. After mice have established a stable baseline alcohol intake, they were given a choice of alcohol or sucrose, with sucrose concentration gradually increasing throughout 6 days. The remaining group was offered water as the alternative fluid. 

Control mice behaved flexibly, preferring alcohol over all sucrose concentrations.. Additionally, when the control group was presented with water instead of sucrose, alcohol levels did not alter. CIE-exposed mice, however, were less responsive: alcohol intake decreased only at the two highest concentrations (6% and 12%) of sucrose. However, in the FSS-alone group, all concentrations of sucrose solutions reduced alcohol intake compared to those that received water instead. The most striking pattern was presented in the CIE + FSS group. Although mice are presented with an alternative palatable solution, mice that have been exposed to CIE and FSS proceeded to have higher preferences for alcohol regardless of sucrose concentration. 

In conclusion, the study shows that mice who are subject to stress through the forced swim test, and mice that have developed a dependence on alcohol show higher alcohol bias. This exemplifies the role of stress and repeated exposure in addiction and AUD. These results further current studies on the circuitry of alcoholism, refine preexisting rodent models of consumption and represent a hallmark of discovery towards understanding addictions.

Work’s Cited

[1] Lopez, M. F., & Becker, H. C. (2025). Increased alcohol-biased choice behavior in mouse models of high alcohol drinking. Alcohol, clinical & experimental research, 49(7), 1435–1444. https://doi.org/10.1111/acer.70076