Rotarod test
The rotarod test was performed to assess the possible motor impairment in animals due to MIA-induced joint damage, as well as the effects of vortioxetine/duloxetine on motor coordination or sedation. The test was performed using a rotarod apparatus (Treadmill for rats 47700; Ugo Basile, Milan, Italy) rotating at a constant speed of 16 rpm. Prior to OA induction, the rats were trained to drive the rotating rod for two consecutive days. Only the rats that managed to stay on the rod for more than 300 seconds were used for the experiment. After injection of MIA/saline, the animals’ ability to balance on a rotating rod (the time the animals spent on the rod before falling off) was tested at different time points (Figure 1).