Grid floor activity cage

Grid Floor Activity cage (Model No. 7430; Ugo Basile, Varese, Italy) and Rotarod (Model No. 7750; Ugo Basile, Varese, Italy) were used for behavior stress tests to examine psychological and locomotor activities, respectively. Hot plate (Model No. 7280; Ugo Basile, Varese, Italy) was used for thermal tests for analgesic effect evaluation. A light microscope was used for examining tissue for histopathology.

Joint stiffness was correlated to the locomotor activity of animlas and measured using open field activity cage method. As previously described [39] (link), animals were left for five minutes in the grid floor activity cage (Ugo Basile, Comerio, Italy). The animals' movements with their paws were converted into electric signals and the number of movements per minute was recorded. The base-line for locomotor activity was recorded (2 days before the primary induction of arthritis) and compared to pre-arthritic phase (10 days after the primary induction of arthritis); mid-arthritic phase (25 days after induction); and late-arthritic phase (40 days after the primary induction of arthritis).