Oral self administration of ethanol in free feeding rats

The use of animal models to study factors involved in excessive alcohol intake has prompted a number of investigators to propose criteria for an optimal model. One of these criterion, oral ingestion of intoxicating amounts of ethanol without concomitant weight loss and/or food restriction, has proven difficult to fulfill, especially when using rats. The following study reports a conditioning paradigm which was used to establish oral ethanol self administration in free feeding rats. Through initial reinforcement of 5% (v/v) ethanol consumption with 20% (w/v) sucrose solution, rats were trained to work for and consume concentrations of ethanol up to and including 40%. Blood ethanol levels above 100 mg ethanol/dl blood were frequently found. A control group, induced to drink quinine with the same procedures, indicated the relative importance of ethanol's pharmacological effect in maintaining high levels of self administration. The results show ethanol can maintain oral self administration of intoxicating quantities of high ethanol concentrations in free feeding rats, when its initial consumption is paired with an additional reinforcer.