Drug administrations

To assess the effect of SSRI on our different targets, we performed chronic and acute administrations of paroxetine, as well as acute administration of 5-HT2C antagonists.

For chronic treatment, paroxetine HCl (Sequoia Research Products, Pangbourne, UK) was administered in drinking water (~5.5 mg/kg/day, starting 4 weeks before the experiments), to avoid stress sensitizing VGV mice with the daily injection stress. Chronic treatment was not interrupted during behavioral studies. Treatment intake was closely monitored and the solution concentration was adjusted per animal, to ensure equivalent intake of paroxetine. Acute paroxetine HCl was injected intraperitoneally (i.p.) at 16 mg/kg (in 0.9% saline). For both paroxetine behavioral studies, experimental timeline is described in Figs. ​Figs.22 and ​and3.3. SB242084 (Abcam Biochemicals, Cambridge, UK) was injected i.p. at 1 mg/kg (in 0.9% saline, 1% Tween 80). Agomelatine (Servier Laboratories, Suresnes, France) was injected i.p. at 50 mg/kg and dissolved in 1% hydroxyethylcellulose (Servier Laboratories).