Abstract
RATIONALE: Discontinuation of chronic and excessive alcohol consumption leads to a dysphoric state in humans. It is not known if there are changes in brain reward function after the discontinuation of an alcohol liquid in rats. OBJECTIVES: The aim of these studies was to investigate the effect of withdrawal from an alcohol liquid diet on brain reward function and acute and protracted anxiety-like behavior. MATERIALS AND METHODS: The intracranial self-stimulation procedure was used to assess brain reward function, and the elevated plus maze test was used to assess anxiety-like behavior. RESULTS: Discontinuation of chronic, 12 weeks, exposure to a 6.2% v/v alcohol liquid diet lead to a minor deficit in brain reward function and did not increase anxiety-like behavior. Discontinuation of chronic, 12 weeks, exposure to a 10% v/v alcohol liquid diet lead to a pronounced deficit in brain reward function and increased anxiety-like behavior. Two weeks after discontinuation of the 10% v/v alcohol liquid diet, the rats with a history of alcohol dependence did not display increased anxiety-like behavior. Restraint stress increased anxiety-like behavior in the rats with a history of alcohol dependence, but not in the control rats. Brain reward thresholds were assessed during the chronic 10% v/v alcohol exposure period. During this period, there were no differences between the brain rewards thresholds of the alcohol and control rats. CONCLUSION: These findings indicate that withdrawal from a 10% v/v alcohol liquid diet leads to a pronounced deficit in brain reward function and acute and protracted anxiety-like behavior in rats.