Figure 3.

A modified reward circuit for the adolescent brain. Connections of the common “reward circuits” are depicted in black and involve nucleus accumbens (NAc), ventral tegmental area (VTA), and medial prefrontal cortex (mPFC). Our findings in adolescents identify a complementary reward processing pathway depicted in red. We find that dopamine projections to the dorsal striatum (DS), which arise from substantia nigra (SNc) may be hypoactive in adolescents (Matthews et al., 2013) while orbitofrontal cortex (OFC) and DS neurons of adolescents are hyper-responsive to reward compared to adults (Sturman & Moghaddam 2011, 2012). On the other hand, NAc dopamine release and reward-evoked activity, and baseline firing of dopamine neurons in the ventral tegmental area (VTA) are comparable between adults and adolescents (Kim et al., 2012; Matthews et al., 2013).