with the dorsomedial striatum while the shell has more diverse features and can be further segregated into subregions (dorsomedial, intermediate, and ventrolateral) based on differences in gross projection patterns (Heimer, Alheid et al. 1997, Usuda, Tanaka et al. 1998) and immunoreactivity to peptides/neurotransmitters (Heimer, Alheid et al. 1997, Zahm 1998). These shell subregions appear to mediate different aspects of the response to drugs of abuse (Ikemoto 2007) and dopamine and reward seeking behavior (Fabbricatore, Ghitza et al. 2009, Reed, Hildebrand et al. 2015). Thus, through connections with limbic circuitry, including the extended amygdala, the ventral portions of the BG also integrate affective information with movement control.
