Abstract

The High-Ethanol Preferring line of rats (HEP), recently selected by R.D. Myers, is characterised by a high voluntary consumption of alcohol (3–4 g/kg/day for males and 6–8 g/kg/day for females, when a 10% ethanol solution is available as a choice vs. water) and a high sensitivity to taste reinforcement (saccharin, quinine). Our previous data obtained with HEP rats showed no evidence of development of dependence after long-term sustained alcohol intake. In this study, we subjected these rats to several long-term administration protocols suggested to favour the development of alcohol dependence, including multiple alcohol concentrations or sweetened alcohol solutions (ethanol 10% or 20%+saccharin), and deprivation periods. The results showed no increase in alcohol consumption, no shift of preference for alcohol solutions when offered as a free choice vs. a preferred saccharin solution, and a very limited alcohol-deprivation effect when alcohol is made available after a period of deprivation, the three criteria used to demonstrate the development of dependence. Regardless of the method used, HEP rats failed to show dependence after long-term, heavy ethanol consumption. Resistance to ethanol dependence may in fact be genetically influenced and the HEP rat appears as a valuable model to search for factors involved in the transition from alcohol abuse to dependence.

Keywords: Alcohol dependence; Alcohol abuse; Saccharin; HEP rat; Taste preference

Article Outline

1. Introduction

2. Animals and methods

2.1. Animals

2.2. Procedures

2.2.1. Study 1: long-term presentation of multiple alcohol solutions

2.2.2. Study 2: long-term drinking of a sweetened alcohol drink (ethanol 10%+saccharin)

2.2.3. Study 3: long-term drinking of a sweetened alcohol drink, high concentration (ethanol 20%+saccharin)

3. Results

3.1. Study 1: long-term presentation of multiple alcoholic drinks

3.2. Study 2: long-term drinking of a sweetened alcohol solution (ethanol 10%+saccharin)

3.3. Study 3: long-term drinking of a sweetened alcohol drink, high concentration (ethanol 20%+saccharin)

4. Discussion

Acknowledgements

References