Limbic dopaminergic adaptation to a stressful stimulus in a rat model of depression

The dopaminergic mesolimbic system has a key role in motivation and reward, and stressful stimuli appear to alter its functionality. Since stress is c onsidered to be one of the primary factors that mediate the expression of d epressive behavior, dopamine and its metabolites in the nucleus accumbens o f control and Flinders Sensitive Line rats, an animal model of depression, were examined prior to and after a forced swim test. In both types of rats, the levels of dopamine metabolites markedly decreased after the forced swi mming, albeit to different extents. In contrast, 60 min after the swim test , dopamine levels were elevated only in the control rats. The accumbal dopa minergic activity is discussed in relation to the behavior of 'depressed' a nd normal rat lines subjected to a stressful event. (C) 2001 Elsevier Scien ce B.V. All rights reserved.