Drinking in the Dark Model to Study Binge-like Consumption of Ethanol and Pharmacotherapies for Alcohol Use Disorder in Outbred Rats
Faculty Sponsor(s)
Lee Bakner and Sarah Coste
Location
Jereld R. Nicholson Library: Grand Avenue
Subject Area
Psychology
Description
Outbred, genetically heterogenous rats are increasingly used to study ethanol drinking as a nonhuman animal model of alcohol use disorder. However, few studies utilize the drinking in the dark (DID) procedure to study binge drinking in outbred rat models. The DID procedure increases ethanol consumption by providing opportunity to consume solution when animals are the most active, 3 hours after the start of the dark phase of the light:dark cycle. The present study used the DID paradigm with two lines of outbred rats (Sprague Dawley and Long Evans) as a model for binge drinking. The initial phase of drinking provided an opportunity to consume 20% ethanol solution. After the 20% ethanol consumption phase, the effect of naltrexone, an opiate receptor antagonist, on consumption of 20% ethanol solution was examined. Subsequent drinking phases (Phases 2 – 4), allowed consumption of a 20% ethanol solution (Phase 2), a 10% ethanol solution (Phase 3), followed by a fourth and final phase where the 10% ethanol solution was sweetened with supersac (0.125% saccharin and 3% glucose). Additionally, several abstinence periods were inserted between and within select drinking phases to explore the effects of abstinence induced drinking. These adaptations were used to further evaluate the validity of the DID procedure as a model of binge consumption of ethanol with outbred rat strains. Results from the 4 phases indicated Long Evans rats consume more ethanol, achieving higher doses of ethanol consumed when compared to Sprague Dawley rats. Naltrexone was found to attenuate ethanol consumption across both strains using the DID procedure. Importantly, introduction of supersac + 10% ethanol solution increased consumption across both strains, and significantly increased binge-like consumption in Long Evans rats, especially after a brief period of abstinence. The present study suggests that consumption of supersac + 10% ethanol solution promotes binge drinking in the outbred, Long Evans rat line using the DID procedure.
Recommended Citation
Rodriguez, Madison; Kesey, Jenae; and Edgington, Olivia, "Drinking in the Dark Model to Study Binge-like Consumption of Ethanol and Pharmacotherapies for Alcohol Use Disorder in Outbred Rats" (2022). Linfield University Student Symposium: A Celebration of Scholarship and Creative Achievement. Event. Submission 21.
https://digitalcommons.linfield.edu/symposium/2022/all/21
Drinking in the Dark Model to Study Binge-like Consumption of Ethanol and Pharmacotherapies for Alcohol Use Disorder in Outbred Rats
Jereld R. Nicholson Library: Grand Avenue
Outbred, genetically heterogenous rats are increasingly used to study ethanol drinking as a nonhuman animal model of alcohol use disorder. However, few studies utilize the drinking in the dark (DID) procedure to study binge drinking in outbred rat models. The DID procedure increases ethanol consumption by providing opportunity to consume solution when animals are the most active, 3 hours after the start of the dark phase of the light:dark cycle. The present study used the DID paradigm with two lines of outbred rats (Sprague Dawley and Long Evans) as a model for binge drinking. The initial phase of drinking provided an opportunity to consume 20% ethanol solution. After the 20% ethanol consumption phase, the effect of naltrexone, an opiate receptor antagonist, on consumption of 20% ethanol solution was examined. Subsequent drinking phases (Phases 2 – 4), allowed consumption of a 20% ethanol solution (Phase 2), a 10% ethanol solution (Phase 3), followed by a fourth and final phase where the 10% ethanol solution was sweetened with supersac (0.125% saccharin and 3% glucose). Additionally, several abstinence periods were inserted between and within select drinking phases to explore the effects of abstinence induced drinking. These adaptations were used to further evaluate the validity of the DID procedure as a model of binge consumption of ethanol with outbred rat strains. Results from the 4 phases indicated Long Evans rats consume more ethanol, achieving higher doses of ethanol consumed when compared to Sprague Dawley rats. Naltrexone was found to attenuate ethanol consumption across both strains using the DID procedure. Importantly, introduction of supersac + 10% ethanol solution increased consumption across both strains, and significantly increased binge-like consumption in Long Evans rats, especially after a brief period of abstinence. The present study suggests that consumption of supersac + 10% ethanol solution promotes binge drinking in the outbred, Long Evans rat line using the DID procedure.
