Meeting Abstract

112.2  Tuesday, Jan. 7 10:30  Kinematics of mice running in exercise wheels SMITH, BJH*; CULLINGFORD, C; USHERWOOD, JR; Royal Veterinary College, London; Royal Veterinary College, London; Royal Veterinary College, London bsmith@rvc.ac.uk

In many fields, mouse locomotion is used as a model for studying the effects of age, stress and genetic disorders. Often these experiments are carried out using exercise wheels, since mice will voluntarily run long distances in wheels, and wheels are compact enough to fit in standard mouse cages. The sample rate of these measurements is typically low; both speed and distance covered are calculated based on number of revolutions per minute, under the assumption that the mouse is running at a constant or near constant speed. While this is sufficient for long term measurements such as daily activity level, it provides little information on kinematic variables such as stride length and duty factor which can be used as indicators of psychological state and to detect neurological conditions. Conversely, most biomechanical studies of mouse locomotion have measured kinematics of a mouse running on a treadmill or over flat ground. It is likely there are significant differences between the kinematics of a mouse running on a wheel and a mouse running on a treadmill or flat ground, due to the shape of the running surface. Additionally, it has been found that mice have preferences for particular wheel designs, and that variations in wheel size can affect running speed and duration. These factors could also have an effect on running kinematics. The research presented here addresses these two issues: firstly by comparing the kinematics of mice running on exercise wheels to those of mice running on treadmills and over flat ground, and secondly by investigating the effect of wheel design on the kinematics of mouse locomotion. A number of factors are considered, including wheel type (upright vs. angled disc), wheel radius, and wheel angle.