DEVELOPMENT OF AUTONOMOUS AND ETHICAL BEHAVIORAL TASKS FOR GROUP-HOUSED MICE USING THE MICECRAFT SYSTEM

In traditional behavioral experiments, animals are often isolated during testing, subjected to food or water restriction to increase motivation, and assessed without respect for their natural activity cycle. Here, we aim to develop more ethical and continuous behavioral paradigms for group-housed mice, allowing voluntary individual access to experimental tasks without any food or water deprivation.
We used the MiceCraft system developed in our laboratory to implement three types of experiments: (i) a touchscreen-based visual discrimination and reversal learning task; (ii) a cooperative task in which mice learn to synchronize their behavior; and (iii) a multidimensional task called the “Playground,” which assesses social (using Live Mouse Tracker technology), motor, and cognitive functions (instrumental and reversal learning).
All tasks were successfully completed by the mice. The visual discrimination and reversal learning task was acquired by all animals within 50 days. In the cooperative task, mice learned to synchronize their behavior within 25 days, and cooperation could be disrupted by modifying interaction conditions. The Playground task generated an individual phenotypic profile for each mouse, including social behavior, general and wheel-based motor activity, and cognitive performance, within less than 72 hours. Relationships between these dimensions could also be investigated.
Together, these results demonstrate that mice can learn complex behavioral tasks while living in a social environment, without food or water restriction. This approach represents an ethical shift, as animals are no longer isolated or temporally constrained, and can engage with experimental modules voluntarily in accordance with their natural activity cycle, thereby likely reducing stress.