It is important to recognize both the strengths and possible limitations of the animal models used to investigate the neural mechanisms of drug relapse. Recent work has addressed the brain circuits important for relapse in rodents after forced abstinence without extinction training. These studies have shown a critical role for the dorsal striatum and midbrain, but not a number of other mesocorticolimbic structures that mediate reinstatement after extinction (Fuchs et al., 2006; See et al., 2007). Extinction experiments in rodents appear to more closely parallel imaging data generated from human psychostimulant addicts (Fuchs et al., 2006; Kalivas, 2008; Kalivas and O’Brien, 2008; Shalev et al., 2002), and extinction efforts have yielded some clinical success (O’Brien et al., 1992). Thus, while these data may be particularly relevant to human addiction, additional temporary inactivation experiments with the abstinence model and more complex choice and devaluation paradigms are needed to provide more thorough insight into human addiction.
