Impact of Fluoxetine on Behavioral Invigoration of Appetitive and Aversively Motivated Responses: Interaction With Dopamine Depletion

Impaired behavioral activation and effort-related motivational dysfunctions like fatigue anergia are debilitating treatment-resistant symptoms of depression. Depressed people show a bias towards the selection low effort activities. To determine if broadly used antidepressant fluoxetine can improve reverse dopamine (DA) depletion-induced anergia, male CD1 mice were evaluated for vigorous escape behaviors in an aversive context (forced swim test, FST), also with exercise preference choice task [running wheel (RW)-T-maze task]. In FST, increased active (swimming, climbing) while reducing passive ones (immobility). However, was not effective at induced by DA-depleting agent tetrabenazine, further decreasing climbing increasing immobility. T-maze, alone produced same pattern effects as tetrabenazine. Moreover, did tetrabenazine-induced suppression RW time but it reduced sucrose intake duration. This DA-depleted dissimilar from devaluing food reinforcement pre-feeding or making bitter since both cases animals compensated RW. Thus, improved decreased relative reinforcement. anergic DA depletion. These results have implications use treating such depressed patients.