Graded Maximal Exercise Testing in Mice

Exercise tolerance in mice (Wt and G93A*SOD1) were assessed by a graded maximal exercise test, as described previously [52 (link),53 (link)]. Briefly, mice were acclimated to the treadmill (OxyletPro, Panlab; Harvard Apparatus, Holliston, MA, USA) in three training sessions and allowed to rest for one week before the experiment. For acclimation, mice were placed in the motionless treadmill, followed by activation of the shock grid (1.5 mA). Subsequently, the treadmill was set up to a walking speed of 6 m/minute (m/min) for 5 min and progressively increased the speed to 12 m/min for 12 min. After a week of rest following acclimation, mice were placed on the treadmill at 0⁰ incline and activated the shock grid. The mice were allowed to run on the treadmill with progressively increasing speeds and inclinations until exhaustion [52 (link),53 (link)]. Mice spending more than 5 s on the shock grid or getting more than 10 shocks indicate exhaustion time. The data were analyzed using Metabolism version 3.0 software (Harvard Apparatus).