Alcohol Oral Self-Administration in Rats: Attempts to Elicit Excessive Intake and Dependence

Abstract

The search for an animal analogue of human alcoholism has been the subject of intense research interest since Richter’s (1) demonstration that a rat will drink weak alcohol solutions in preference to water. However, in the three decades following these studies there has yet to be a demonstration of addiction to alcohol in an animal when oral se1f-administration techniques have been employed (e.g., 2,3). This conclusion is based on the fact that in no self-selection study, even those in which “experimental alcoholism” has been claimed, have the criteria of drug and, specifically, alcohol addiction been met. These criteria are: 1) The oral self-administration of alcohol, in the absence of food deprivation, in amounts sufficient to regularly produce intoxication, as determined by both behavioral analysis and blood alcohol levels; 2) The development of tolerance to alcohol’s effects after chronic oral self-administration; 3) The development of a withdrawal syndrome (i.e., physical dependence) upon abrupt withdrawal of alcohol following a period of chronic self-administration; and 4) The development of “psychological dependence” on alcohol, as indicated by, for example, the animals self-selection of alcohol to avoid a withdrawal syndrome or willingness to perform work or overcome an imposed barrier to obtain alcohol. Although a number of investigators have recently reported the production of physical dependence on alcohol in several species and by a variety of procedures (4,5,6,7), it can be unequivocally stated that, on the basis of the criteria outlined above, an animal analogue of human alcoholism has not yet been generated.