During adolescence, the enhanced drive to explore, take risks, and experiment with novel aspects of life are thought to be due to a “disparate developmental trajectory” between the mesocorticolimbic reward and frontal cortical executive control systems [26,27]. The refinement of these systems during adolescence is extensive. In the prefrontal cortex (PFC), significant glutamatergic pruning decreases cortical volume, while cholinergic and dopaminergic innervation increase to adult levels [4,27,28]. In addition, a sharp peak in dopamine levels within the nucleus accumbens occurs in late adolescence before falling to adult levels [23,27,29].
