Nucleoside transporter (NT) and nucleic-related enzyme (NRE) play key roles in the physiology of nucleosides and the pharmacology of its analogs in mammals. In this study, we examined the effect of fluoxetine, a selective serotonin reuptake inhibitor, and pergolide, a dopamine D receptor agonist, on the expression of NTs and NREs in mouse brain. It was confirmed by the detection of corresponding mRNAs that three equilibrative nucleoside transporter (ENT1-3) isoforms, concentrative nucleoside transporter 2 (CNT2), CNT3, adenosine kinase (AK), and apyrase, but not CNT1, were expressed in brain tissue. Based on an assessment by mRNA determination, the cerebral expression of CNT2 was found to be increased by administration of fluoxetine and pergolide to mice. Furthermore, pergolide increased the expression of ENT2. However, fluoxetine and pergolide had no significant effect on the expression of mRNA for other NTs, AK, and apyrase. Therefore, we concluded that the expression of several NT isoforms, but not NREs, in mouse brain was affected by treatment with fluoxetine and pergolide.