Others have focused on the importance of mesolimbic DA projections in circuitry involved with learning about rewards, citing research suggesting that DA is critical for “stamping in” reward learning, or for detecting errors in reward prediction, with the resulting DA release serving as a “teaching signal” for new learning when a predicted reward is not received (see Hollerman et al., 2000; Berridge, 2007, for review and references). Such reward-based learning is thought to involve neurocircuitry that includes afferents and efferents from both ventral parts of the striatum (i.e., the NAc) and from dorsal striatum (e.g., nigrostriatal DA system) (Meredith et al., 2008), along with the amygdala, hippocampus, and regions of frontal cortex (e.g., see Berridge & Kringelbach, 2008).
