al. tested the MEK inhibitor SL 327 for ethanol self-administration in C57BL/6 mice and observed a biphasic response to MEK inhibition [42]. Low doses increased operant responding for ethanol, while high doses decreased responding. Ethanol induces c-fos expression, an effect that is suppressed in alcohol-dependent animals [43]. This suppression is alleviated by the MEK inhibitor UO126 only in dependent animals, suggesting a complicated relationship between MEK activity and alcohol dependence.
