2.7.1 Rotarod test
Motor coordination, ataxia, and equilibrium were measured by using a rotarod apparatus (Ugo Basile, Varese, Italy). Mice were placed in the testing environment in their home cage and allowed to acclimate for at least 1 hr to minimize effects of stress on behavior during testing. During a training session, mice from the same cage were placed in separate lanes on a rod rotating at 5 rpm such that the animals were able to walk forward and keep their balance. After 60 s, animals were returned to their home cage, and the apparatus was wiped with a cleaning solution. This procedure was repeated three times at 10-min intervals. If the animal fell off the rod before the 60-s cutoff, the trial was repeated. However, no more than four trials were run per animal. Only the animals that were able to remain on the rod rotating at 5 rpm for 60 s were used in the study. During the testing stage, animals from the same cage were placed in separate lanes on a rod that was initially rotating at 4 rpm. The apparatus was set to accelerate from 4 to 40 rpm in 300 s (Deacon, 2013). The trial began when the acceleration started and ended when the animal fell from the rod. If the animal clung to the rod and completed a full passive rotation, the timer was stopped, and the passive rotation was noted. Care was taken not to disturb animals in adjacent lanes. This procedure was repeated for three trials. Latency to fall and speed at fall were recorded, and the averages of the three trials were used for data analysis.