DEPLETION OF MESOLIMBIC DOPAMINE DURING BEHAVIORAL DESPAIR - PARTIAL REVERSAL BY CHRONIC IMIPRAMINE

Exposure of rate to the behavioral despair test (an animal model of de pression) for 40 min resulted in a long-lasting depletion of mesolimbi c dopamine output to about 40% of baseline values. The decrease in ext racellular dopamine was partially prevented by chronic pretreatment wi th imipramine (20 mg/kg per day i.p. for 21 days). The results suggest that a fall in mesolimbic dopamine output may be associated with depr essive states and indicate that changes in the functional status of th e dopamine system contribute to the mechanism of action of imipramine.