Several reports have noted that there is dopamine receptor overproduction followed by pruning during adolescence (Teicher et al., 1995). Striatal and NAcc dopamine receptor binding of D1 and D2 receptors peaks in adolescence (P40) at levels that are about 30–45% greater than those seen in adulthood (Teicher et al., 1995; Tarazi et al., 1998, 1999). Using autoradiography in male and female rats, Andersen et al. (1997) showed a sexual dimorphism of this effect, such that adolescent males had greater overproduction (approximately 4.6-fold) and elimination of striatal D1 and D2 striatal receptors than adolescent females. Interestingly, these effects are not mediated by gonadal hormone surges (Andersen et al., 2002) but do appear to have functional consequences (Andersen and Teicher, 1999) that may correspond with behavior. A similar pattern is observed in prefrontal cortex, albeit with a more protracted elimination period (Andersen and Teicher, 2000). Confocal microscopy has revealed that retrogradely traced cortical output neurons in the prefrontal cortex express higher levels of D1 receptors during adolescence than older or younger rodents (Brenhouse et al., 2008). These rodent findings coincide with human
