Oral Binge-Like Ethanol Pre-Exposure During Juvenile/Adolescent Period Attenuates Ethanol-Induced Conditioned Place Aversion in Rats

• Published in: Alcohol and alcoholism (Oxford) Vol. 53; no. 5; pp. 518 - 525
• Main Authors: Williams, Keith L, Nickel, Melissa M, Bielak, Justin T
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-09-2018
• Subjects: Administration, Oral; Age Factors; Alcohol Drinking - psychology; Alcohol Drinking - trends; Animals; Avoidance Learning - drug effects; Avoidance Learning - physiology; Binge Drinking - psychology; Binge Drinking - trends; Conditioning (Psychology) - drug effects; Conditioning (Psychology) - physiology; Ethanol - administration & dosage; Male; Motor Activity - drug effects; Motor Activity - physiology; Rats; Rats, Sprague-Dawley
• ISSN: 0735-0414; 1464-3502
• DOI: 10.1093/alcalc/agy040

Modified conditioned place preference paradigm allowed rats to orally self-administer ethanol followed by short duration exposure to conditioning chambers. Ethanol produced a conditioned place aversion even though rats self-administered ethanol following the final conditioning test. Juvenile/adolescent pre-exposure to ethanol decreased the place aversion but did not produce place preference.
Abstract
Aims
To determine if oral ethanol self-administration produces a conditioned place preference (CPP) and to determine if ethanol pre-exposure conditions during the juvenile/adolescent period alter the conditioned effects of ethanol and subsequent ethanol self-administration.
Short summary
Modified conditioned place preference paradigm allowed rats to orally self-administer ethanol followed by short duration exposure to conditioning chambers. Ethanol produced a conditioned place aversion even though rats self-administered ethanol following the final conditioning test. Juvenile/adolescent pre-exposure to ethanol decreased the place aversion but did not produce place preference.
Methods
Juvenile/adolescent rats consumed sweetened 5% ethanol in the home-cage either during continuous access or intermittent access with water restriction that promoted binge-like consumption. A control group had water access during the 4-week period. Adult rats were conditioned using a modified CPP paradigm wherein rats were water-restricted overnight before being placed in operant chambers to respond for 5% ethanol for 7 min. Following the operant session, rats were placed in the conditioning chamber for 8 min. After the conditioning post-test, rats self-administered ethanol during daily operant sessions.
Results
Ethanol produced a conditioned place aversion in water access rats and the continuous access rats. Binge-like ethanol consumption induced by intermittent access with water restriction abolished the place aversion, but did not allow place preference to develop. After conditioning, continuous access rats self-administered ethanol above ~0.6 g/kg which was similar to rats with binge-like experience via intermittent access.
Conclusions
Results suggest that oral ethanol self-administration elicits aversive properties in this model even though ethanol continues to maintain self-administration. Pre-exposure to ethanol during the juvenile/adolescent period may produce tolerance to ethanol’s aversive properties only when consumed in a binge-like manner with water restriction. More exploration is needed to understand how behavioral history can influence sensitivity to ethanol’s rewarding and aversive properties and subsequent ethanol consumption or self-administration.