We then asked if mice with altered levels of NrCAM expression display differences in conditioned place preference, which provides a relatively robust test for alterations in the reward and reward-memories induced by abused substances. Heterozygous and/or homozygous NrCAM knockout mice display striking reductions in their preferences for the places where they received either morphine or methamphetamine, in comparison to wildtype control mice. By contrast, mice of all genotypes displayed similar sensitivities to the acute locomotor stimulant properties of all three drugs.
