peak developmentally in striatum and limbic regions during adolescence (P30–40 in rats), before declining significantly to reach adult levels (Rodriguez de Fonseca et al., 1993). Notable developmental transformations in endocannabinoid levels also are evident during adolescence, with, for instance, developmental increases in anandamide, but declines in 2-Arachidonoylglycerol (2-AG) seen throughout adolescence in PFC (Ellgren et al., 2008). Thus, although much of the focus to date has been on alterations in DA-related systems in adolescence, these are embedded within other transformations in reward-related circuitry that have yet to be extensively explored but that are likely to contribute critically to adolescent-typical responding to rewarding stimuli.
