TRAINING A LARGE NUMBER OF LABORATORY MICE USING RUNNING WHEELS AND ANALYZING RUNNING BEHAVIOR BY USE OF A COMPUTER-ASSISTED SYSTEM

A great many studies in the literature describe the variety of ways to provide physical training to small laboratory animals, Forced running on a treadmill or swimming training require considerable effort from the researcher, but permit the investigator to control the amount of e xercise, Another option is to provide animals with access to running w heels, which they can voluntarily operate. Wheels can be used to inves tigate the running behavior of the animals, Wheel motion usually has b een detected with magnets and microswitches and has been recorded usin g strip chart recorders or electromechanical counters, Computers also have been used in recording, but the measured parameters usually have been able to define only the total distance run in a fixed period, We designed a system, using running wheels, that can be used for long per iods, up to years, for training a large number of laboratory mice simu ltaneously (maximal n=96). The running parameters estimated by our sys tem include running distance, speed, and time. Cumulative estimates of the running parameters can be produced for any period, as short as 1 sec. It is also easy to perform statistical analyses on the data, Usin g the system, we investigated the running behavior of 21 young C57BL/6 male mice, After the fast growth period, until 8 weeks of age, the mi ce ran 4 to 5 km/day at an average speed of 23 m/min, and spent 3 h ru nning each day, This took place during the hours of darkness.