RATIONALE: Current hypotheses on the etiology of @entity308 attribute the disorder to alterations in @entity750 and @entity1063 neurotransmission. However, the relationship between these alterations and @entity146 is poorly understood. Conversely, an interaction between the serotonergic and dopaminergic systems in the nucleus accumbens has been established. Since motivation and hedonia have been associated with @entity935 release in the nucleus accumbens, we decided to test its modulation by @entity750 in relation to @entity308 -like behavior. OBJECTIVES AND METHODS: The extracellular @entity935 levels in the nucleus accumbens were studied in vivo in Flinders Sensitive Line (FSL, a @entity35 model of @entity146 ) and control @entity35 , before and after antidepressant treatment. @entity35 were chronically treated with the antidepressants @entity5829 (5 mg/kg/day) and @entity903 (7.5 mg/kg/day) for 18 consecutive days. As a measure of @entity146 we used a modified swim test. The release of @entity935 in response to local @entity750 application was monitored using the microdialysis technique. RESULTS: @entity750 (0.5 microM) facilitated @entity935 release in the nucleus accumbens of control @entity35 . In FSL @entity35 , basal extracellular @entity935 levels in the nucleus accumbens were 40% lower than in control @entity35 and did not increase in response to @entity750 stimulation. However, chronic antidepressant treatment of the FSL @entity35 normalized the @entity750 - @entity935 interaction as well as their @entity146 . CONCLUSIONS: The inability of @entity750 to stimulate @entity935 release in the nucleus accumbens, thereby leading to @entity4270 and lack of motivation, may therefore be an essential factor in the onset of @entity308 and a target for modulation by antidepressant drugs.

Association between @entity146 and absence of @entity750 - XXXX interaction in the nucleus accumbens.

@entity308 :: ('MESH:D003866', 'Disease') :: ['depression', 'depressive'] @entity146 :: ('MESH:D001523', 'Disease') :: ['depressive behavior', 'behavioral deficiencies'] @entity935 :: ('MESH:D004298', 'Chemical') :: ['dopamine'] @entity5829 :: ('MESH:D003891', 'Chemical') :: ['desipramine'] @entity903 :: ('MESH:D017374', 'Chemical') :: ['paroxetine'] @entity4270 :: ('MESH:D059445', 'Disease') :: ['anhedonia'] @entity750 :: ('MESH:D012701', 'Chemical') :: ['serotonin', 'Serotonin'] @entity35 :: ('10116', 'Species') :: ['rat', 'Rats', 'rats'] @entity1063 :: ('MESH:D009638', 'Chemical') :: ['norepinephrine']
@entity935 :: (MESH:D004298,Chemical) :: ['dopamine']
