Differential regulation of DOPAC/DA and DA level after overexpression of MOR in NAc and VTA. a NAc and b VTA tissues were harvested at 22 days after administration of AAV-MOR or AAV-GFP to NAc or VTA. A1 In NAc tissue, infusion of AAV-MOR in NAc (MOR/NAc), AAV-GFP in NAc (GFP/NAc), AAV-GFP in VTA (GFP/VTA), or AAV-MOR in VTA (MOR/VTA) did not alter tissue DA levels. A2 Administration of AAV-MOR to NAc (MOR/NAc) significantly reduced DOPAC/DA turnover ratio (p<0.001) in NAc. B1 In VTA tissue, administration of AAV-MOR to VTA (MOR/VTA) significantly increased DA levels in VTA (p<0.01). B2 MOR-VTA did not alter DOPAC/DA in VTA (p>0.05). MOR/Ac overexpress MOR in NAc, GFP/Ac overexpress GFP in NAc, GFP/VTA overexpress GFP in VTA, MOR/VTA overexpress MOR in VTA