drug-related cues while de-emphasizing all other non-drug stimuli or cues. This is hypothesized to bias the animal s behavior toward drug-related stimuli while precluding expression of other behaviors. In essence, behavior flexibility is lost as the animal becomes increasingly focused on performing drug-associated behaviors (Kalivas and O Brien, 2008). In the NAcb, similar drug-induced changes in these neurons can facilitate a preferential excitation of neurons that respond to drug-associated cues that could also promote execution of drug-associated behaviors.
