Nicotine Actions in Models of Learning/Memory and Reward

Abstract

Nicotine appears to be the primary substance responsible for maintaining the use by humans of tobacco products. Although it is readily demonstrated that nicotine is capable of inducing psychologic, physiologic, and pharmacologic changes in both animals and humans, these effects may not necessarily relate directly to the phenomenon of tobacco use in humans. Although many past experiments in both animals and humans have given rise to many isolated hypotheses as to why people use tobacco, there has been little integration of the results of these many, isolated experiments. This laboratory has been using the methods of strong inference and of multiple working hypotheses to address the question, “Why do people smoke?” This report will integrate the results from two aspects of the effects of nicotine: those effects of nicotine on learning and memory, and those effects of nicotine on the subjective state. We will use this integration to formulate a new hypothesis based upon the commonalities shared by learning/memory and reinforcement of behavior. This approach using multiple hypotheses will lead to a better understanding of the phenomenon of tobacco use in humans.