Associative learning, the hippocampus, and nicotine addiction.

The abuse liability of nicotine is comparable to or greater than that of a variety of addictive substances. However, the reinforcing and/or rewarding properties of addictive substances other than nicotine far outweigh the reinforcing and/or rewarding effects associated with nicotine use. These data suggest that, in addition to the intrinsic reinforcing effects of nicotine, other factors may contribute to nicotine addiction. One such factor is associative learning, or rather, the ability of nicotine to alter learning and memory processes that may underlie addiction. The present paper presents an overview of the role of learning in nicotine addiction. In addition, recent advances in the identification of behavioral processes, neural substrates, and cellular and molecular substrates that underlie nicotine-associated alterations in learning are reviewed. Particular attention has been paid to research that describes the role of the hippocampus and hippocampus-dependent learning processes in nicotine addiction.