Antidepressant-like activity of S 20098 (agomelatine) in the forced swimming test in rodents: involvement of melatonin and serotonin receptors

These results demonstrate the antidepressant-like activity of repeated administration of S 20098 in the FST. Moreover, the combination of 5-HT agonists and antagonists leads to more powerful effects with S 20098 than with melatonin, thereby emphasizing the contribution of 5-HT receptors to the antidepressant activity of S 20098. Compared with imipramine and fluoxetine, the 5-HT receptor subtypes that may be involved in the antidepressant-like activity of S 20098 are not similar. Indeed, when considering the binding properties of S 20098, the 5-HT(2C) receptor subtype appears to be the most attractive candidate. It is concluded that the antidepressant-like activity of S 20098 in this model most probably involves a combination of both its melatonin agonist and 5-HT(2C )receptor antagonist properties.