There is general agreement that the glutamatergic projection from the prefrontal cortex to the NAcb core is critical for the reinstatement of cocaine-seeking behavior (Bachtell et al., 2008; Backstrom and Hyytia, 2007; Cornish et al., 1999; Cornish and Kalivas, 2000; Di Ciano and Everitt, 2001; McFarland et al., 2003; McFarland et al., 2004; Park et al., 2002; Ping et al., 2008). Importantly, upon repeated performance, drug-seeking behavior becomes less adaptive and less receptive to shaping via anterior cingulate, prefrontal and orbital frontal executive oversight (Everitt and Robbins, 2005; Goldstein and Volkow, 2002; Kalivas, 2008; Kalivas and Volkow, 2005), with greater control exerted by sensory-motor cortical input into the dorsal striatum (Everitt and Robbins, 2005). Importantly, recent evidence also suggests that the ventral and dorsal striatum interact to control habitual behavior (Belin and Everitt, 2008). Together, these data suggest that repeated psychostimulant use reduces cortical interaction with habit circuitry. However, during drug abstinence, relapse can be precipitated by increased cortical activity that may feed forward into what now may be habitual, drug-directed responses.
