In sum, given the role of the DYN/KOR system in mediating negative affect and aversive-related behaviors (Al-Hasani et al., 2015; Land et al., 2008; Van’t Veer and Carlezon, 2013), it is not surprising that KOR activation has been shown to alter ethanol-conditioned reward. However, there is a paucity of studies devoted to this issue and, as outlined in Table 1, results from these studies have been generally inconsistent. Dose and timing of agonists in relation to ethanol administration appear to be critical factors in influencing effects of KOR activation on ethanol-induced CPP. Additional work in this area will be needed to better define how modulation of KOR activity influences ethanol-related conditioned reward and aversion.
