Schedule-induced consumption of ethanol: calories or chemotherapy?

Abstract Thirty-two Charles River and 16 Sprague-Dawley male rats were studied in independent and replicated designs in which: (a) schedule-induced (FI-60 sec) consumption of water, acetone and ethanol, conditioned by bar pressing for food pellets, was followed by extinction of the bar pressing response; (b) there was a 12 day interval before extinction session; and (c) licking for a fluid (not bar pressing) was the contingent response for food and also was not reinforced during extinction. While ethanol continued to be consumed in substantial volume during extinction, acetone and water were not. The failure to continue the equi-intoxicating, but essentially non-caloric, acetone consumption supports the hypothesis that the caloric value of ethanol, and not its pharmacodynamic action, is a prime factor in its ingestion. Further study of the basis for the rats' ethanol drinking appears necessary if non-human models of addiction to alcohol are to be pursued.