Clicker Training Mice for Improved Compliance in the Catwalk Test

SIMPLE SUMMARY: Refinement-oriented research remains essential for animal welfare and data reproducibility. When evaluating mouse locomotion, the implementation of the CatWalk XT is helpful for gait assessment, but its application requires eliciting movement of the animals across the corridor, usually by forcing them with unpleasant stimuli. In this study, we tested the efficacy of clicker training to increase performance with the CatWalk test while assessing behavioral changes in the Open Field and Elevated Plus Maze to address the well-being of trained and untrained mice. Clicker training improved running speed on the CatWalk for both sexes. Interestingly, clicker training appeared to reduce anxiety and improve general well-being parameters in the Open Field and the Elevated Plus Maze tests to a greater extent in females. We conclude that clicker training enhances the performance of mice on the CatWalk and is a promising alternative for welfare improvement. ABSTRACT: The CatWalk test relies on the run of mice across the platform to measure a constant speed with low variation. Mice usually require a stimulus to walk to the end of the catwalk. However, such stimuli are usually aversive and can impair welfare. Positive reinforcement training of laboratory animals is a thriving tool for refinement and contributes to meeting the demands instituted by Directive 2010/63/EU. We have already demonstrated the positive effects of clicker training. In this study, we trained male and female mice to complete the CatWalk protocol while assessing the effects of training on their well-being (Open Filed and Elevated Plus Maze). In the CatWalk test, we observed that clicker training improved the running speed of the mice. In addition, clicker training reduced the number of runs required by mice, which was more pronounced in males. Clicker training lowered anxiety-like behaviors in our mice, especially in females, where a significant difference was observed between trained and untrained ones. Based on our findings, we hypothesize that clicker training is an effective tool to motivate mice and increase performance on the CatWalk test without potentially impairing their welfare (e.g., by puffing them).