Antidepressant-like effects of rosiglitazone, a PPAR gamma agonist, in the rat forced swim and mouse tail suspension tests

Several studies have evaluated thiazolidinedione therapy as medical treatments for some central nervous system disorders, such as cognitive deficits associated with neurodegenerative disorders. However, there is limited data to support a direct role for peroxisome proliferator-activated receptor-gamma agonists; in depression. Therefore, the aim of this study was to investigate antidepressant-like activity of rosiglitazone using the mouse tail suspension test and the rat forced swimming test, two models sensitive to the effects of antidepressants. In the tail suspension test, 5 days of treatment with rosiglitazone (8.5 or 17 mg/kg, orally) reduced immobility time. In the forced swimming test, rosiglitazone (6 or 12 mg/kg, orally) treatment decreased immobility time and increased climbing. These effects were not accompanied by any alteration in locomotor activity in the open field test. Rosiglitazone treatment (6 or 12 mg/kg, orally) significantly reduced plasma corticosterone levels in rats. GW9662 significantly inhibited the rosiglitazone-induced reduction in the duration of immobility. In summary, this study suggests that rosiglitazone possesses a specific antidepressant-like activity in behavioral models and that this effect may be mediated by reduction of plasma corticosterone level. Behavioural Pharmacology 20:635-642 (c) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.