Presenting Author University of Vermont Larner College of Medicine
Modeling exercise in small animals is more difficult than it may appear. Current methods are either voluntary (wheel running) or forced (treadmill running) protocols. Although commonly used, each have several drawbacks that limit enthusiasm for their adoption. While mice will instinctively run on a wheel, current methods lack the ability to restrain mice from traveling 10-20 km per day. Forced exercise, while controllable, puts animals into stressful environments in which they are confined and often shocked for “encouragement.” Additionally, both methods require expensive equipment and software, which limit these experiments to well-funded laboratories. To counter these issues, we developed a non-invasive mouse running device aimed to reduce handler-induced stress, provide time and distance based stopping conditions, and enable investigators with limited resources to easily produce and use the device. The Lockable Open-Source Training-Wheel (LOST-Wheel) was designed to be 3D printed on any standard entry-level printer and assembled using only a few common tools for around 20 USD (Figure 1 A-C). It features an on-board screen and is capable of tracking distances, running time, and velocities of mice. The LOST-Wheel overcomes the largest drawback to voluntary exercise, which is the inability to control when and how long mice run, using a servo driven mechanism that locks and unlocks the running surface according to the protocol of the investigator. While the LOST-Wheel can be used without a computer connection, we wanted to provide scientists additional data and designed the LOST-Wheel Logger, an R-based application that presents milestones and plots on a user-friendly dashboard (Figure 1D). Seven-day running experiments confirm distances comparable to other reports (Figure 1E). Using the LOST-Wheel we implemented a timed running experiment which showed distance-dependent decreases in serum myostatin as well as IL-6 gene upregulation in muscle. To make this device accessible, we are releasing the designs, application, and manual in an open-source format. The implementation of the LOST-Wheel and future iterations will improve upon existing murine exercise equipment and research.
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Funding: Larner College of Medicine and the Vermont Lung Center T32HL076122.lt;/pgt;lt;pgt;Larner College of Medicine and the Vermont Lung Center T32HL076122.lt;/pgt;
Figure 1 Lost-Wheel assembly and testing. A) Computer rendered design of the assembled LOST-Wheel. B) Completed assembly of the LOST-Wheel. C) Simplified wiring diagram of components D) The LOST-Wheel Logger Application E) Seven-day test of the LOST-Wheel (n=5).
