et al., 2008; Volkow et al., 2005). The OFC is a major area of motivation, drive and salience evaluation, which is impaired in drug addicts and plays an important role in the output of compulsive drug-seeking behaviors (Volkow and Fowler, 2000). In the present study, significant resting-state functional connectivity was found between NAc and ventral/rostral ACC, and medial OFC, consistent with the results of a recent study on the functional connectivity of striatum (Di Martino et al., 2008). Amygdala is thought to primarily contribute to the acquisition, consolidation and expression of learning of the drug-related cues that drive relapse to drug-seeking behaviors (Hyman et al., 2006; Robbins et al., 2008). This area is also important for craving processing, robustly activated under drug-related cues (Diekhof et al., 2008) (even for the unseen ones (Childress et al., 2008; Zhang et al., 2009)), involved in signaling pleasure of immediate prospects which are related to impulsive behaviors (Bechara, 2005) and was found to exhibit robust resting-state functional connectivity with affective brain areas including OFC (Roy et al., 2009). Our finding of higher functional connectivity between NAc and ventral ACC and OFC, between amygdala and OFC in HU may be relevant to previous studies that
