Similarly, comparisons between mice bred for excessive exercise or obesity revealed that NAc dopamine content was increased in high running compared to obese and control mice, while Drd1, Drd2, and adenylate cyclase 5 (Adcy5) mRNAs were downregulated 92, 80, and 91%, respectively, in obese compared to control mice (78). The gene discussed is ADCY5; the disease is obesity due to melanocortin 4 receptor deficiency.