Stark differences exist between adult ($>$PND 70) and juvenile ($∼$PND 21– 34) rodents in how DCC (deleted in colorectal cancer) receptors and sensitization to amphetamine interact. In adults, repeated amphetamine upregulates DCC receptor expression selectively in the ventral tegmental area (VTA), an effect that is critical for sensitization. In contrast, amphetamine administered to juveniles downregulates VTA DCC expression. Moreover, whereas adult dcc heterozygous mice fail to sensitize when repeatedly treated with amphetamine, drug treatment during the juvenile period actually abolishes this adult ``protective’’ phenotype.