Recent evidence suggests that early developmental stress experience can influence DYN/KOR system modulation of neurochemical and behavioral effects of ethanol. Jones and colleagues reported that social isolation during adolescence resulted in reduced basal dopamine in the nucleus accumbens and elevated ethanol consumption in adult rats, effects that were both blocked by the KOR antagonist nor-BNI (Karkhanis et al., 2016b). Further, rats with early stress (isolation housing) experience evidenced greater sensitivity to the ability of the KOR agonist U50,488 to reduce dopamine release in the nucleus accumbens in comparison to their group-housed counterparts. These results suggest that the DYN/KOR system is sensitized in animals subjected to early life stress and consequent elevated drinking may be mitigated by pharmacological blockade of KORs. Additional studies probing how the DYN/KOR system is influenced by stress and ethanol exposure, and how such changes may influence motivational effects of ethanol are certainly warranted.
