“…Similarly, intra-VTA infusion of the GABA B R agonist baclofen blocked the locomotor-stimulatory effect of psychostimulants and opioids ( Kalivas et al, 1990 ; Steketee and Kalivas, 1991 ; Chen and Reith, 1994 ; Leite-Morris et al, 2002 , 2004 ) and attenuated self-administration of cocaine, opioids, and other drugs of abuse ( Xi and Stein, 1999 ; Brebner et al, 2000 ; Leite-Morris et al, 2004 ; Backes and Hemby, 2008 ). RNAi-mediated suppression of D 2 R in the rat VTA (cell non-selective) enhanced cocaine-related behavior ( de Jong et al, 2015 ; Chen et al, 2018 ), enhanced choice impulsivity ( Bernosky-Smith et al, 2018 ), and increased functional brain activity ( Martin et al, 2020 ). Ablation of D 2 R in DA neurons throughout the mouse brain correlated with enhanced cocaine-induced activity ( Bello et al, 2011 ), as well as acquisition of cocaine self-administration and reactivity to drug-paired cues ( Holroyd et al, 2015 ).…”