While mechanized treadmills have existed for close to a century, it is only recently that such devices have been miniaturized and tailored for the study of animal locomotion and metabolism. Originally designed for cardiovascular studies in hospitals, a motorized treadmill allows for a consistent and adjustable running speed, an advantage over unpowered alternatives. Although scaled down traditional treadmills from several companies are available for animal studies, the LE8710M rodent locomotor-fatigue and metabolism unit from Panlab is an innovative unit with a few noteworthy enhancements and conveniences.
In addition to being designed for fully automated operation via computer, the LE8710M is available in a range of sizes (one to five lanes), and gives investigators the option to utilize an airtight enclosure for metabolism studies. The unit is adjustable for incline, and has a footprint of approximately four square feet, which can be reduced for storage. Because treadmills are becoming increasingly popular with groups studying locomotive function with recording equipment, the units are supplied with enclosed lanes made of clear acrylic which allow for clear observation of the interior. Animals are encouraged to stay on the treadmill with a built-in “shock scrambler”, which applies an adjustable current of electricity to lagging animals near the rear edge of the unit. A small tray is placed under the scramblers to catch debris and animals, although the placement of the electric prongs obstructs easy egress.
The particular model procured for review was a five-lane device for mice, and included the SeDaCom software control package. After a successful order was placed for the unit, the wait time was about eight weeks for delivery. Although relatively easy to assemble, the treadmill and its software package required significant effort to use in conjunction with laboratory computers, primarily attributable to poorly designed software, and the usage of the obsolete RS232 (serial port) standard.
After successfully installing the treadmill and SeDaCom software, the LE8710M was utilized in a series of zero degree incline trials over the course of seven months with several cohorts of mice. Mechanical reliability proved to be excellent, with intermittent adjustments made to the belt and regular superficial cleaning of the device. The software package allowed untrained operators to create a regimen of various speeds and times for the treadmill, as well as recording the statistics for each run.
Although operation of the LE8710M is straightforward, there are several situational factors to consider in its use. For example, although it is advertised to progress in speed from 0 cm/s to 150 cm/s, the lowest moving speed is a significant 5 cm/s which can easily overwhelm motor-deficient mice. Additionally, while mice are segregated on the belt itself, they can mingle on the “receiving” stationary platform under the shock scramblers. As expected, a significant amount of debris and animal waste accumulates on the belt and the stationary platform, which is detachable for cleaning purposes. A concern for metabolism studies may be the inaccuracy of the reported belt speed, which proved to be at worst, 25% higher than the actual speed that the mice were encouraged to negotiate. Although a fantastically reliable product, it is perhaps due to its complexity and expanded features that the treadmill package leaves ample room for refinement. Despite these shortcomings, the LE8710M series by Panlab is an impressive product in light of its purpose, and a dependable device for investigators studying small animal locomotion.
Student Researcher
Molecular Biophysics and Biochemistry
Yale University