Drug addiction and learning are intertwined on at least two levels. The effects of behavioral contingencies (e.g., Pavlovian) on withdrawal, cravings, and motivations for drugs extended the field of learning into that of drug abuse. Contemporary theories that treat drugs as reinforcers, thereby classifying drug abuse as behavior reinforced by its consequences, or in other words, operant behavior, has also bridged drug abuse and learning theory. Thus, the conceptualization of drug-taking, -seeking, abuse, and addiction in the terms of learning theory has been one of the most significant advances in the fields of drug abuse and experimental psychology. Concurrent with the developments in learning theory, neuroscientists were discovering that the neurophysiological changes that accompany learning appear to be mediated by the mesocorticolimbic pathway, a pathway known for its modulation of the effects of drugs as well. Our understanding of this system's basic evolutionary function, however, is still not well-known. Thus, I propose to explore part of the network that instantiates operant learning, especially circuitry in the nucleus accumbens and amygdaloid complex through NMDA and D 1 receptor activation. The proposed research integrates cannula mapping techniques, pharmacological manipulations and advanced behavioral analysis.
