Assessing anxiety and reward-related behaviors following alcohol administration or chronic stress


Dysregulation of stress- and reward-related neurocircuitry that results from experience with alcohol or chronic stress may underlie vulnerability to initiate or relapse to alcohol use. Related changes in behaviors associated with such dysregulation may provide insight into factors that increase or decrease vulnerability to alcohol dependence in humans. In the present study, anxiety-like behavior and the acquisition of conditioned place preference were assessed in male Wistar rats with differing histories of exposure to stress or alcohol two weeks following the termination of treatment. Thus, time spent on the open arms of the elevated plus maze as well as the number of days required to acquire alcohol-based place conditioning were evaluated in control animals vs. those with a history of exposure to chronic unpredictable stress, experimenter-administered intragastric alcohol, or selfadministered alcohol liquid diet. Exposure to chronic unpredictable stress decreased open arm exploration on the elevated plus maze while no difference in open arm exploration was observed between the control group and alcohol-administration groups. However, animals with a history of intragastric ethanol administration or chronic unpredictable stress acquired alcohol-based placed conditioning after 3 alcohol-context pairings while control animals and animals with a history of alcohol self-administration required 4 alcohol-context pairings to acquire a significant preference for the alcohol-paired compartment. Results reveal that 1) a history of alcohol contributes to the acquisition of conditioned place preference but is dependent on the administration regimen and 2) chronic unpredictable stress enhances the acquisition of alcohol-based conditioned place preference and produces anxiogenic performance. These findings suggest overlap in the neuroadaptive changes that result from chronic exposure to alcohol or stress which may contribute to vulnerability to alcohol use.

Journal of Alcoholism & Drug Dependence, 1(7), 1–7.