DEVELOPING LOCKBOXES FOR TESTING PROBLEM-SOLVING IN RODENTS

Lockboxes are mechanical puzzles whose solution unlocks a food reward. In laboratory rodents, they can be used to assess problem-solving skills and as enrichment tools in the home cage. Previous research showed that within a few days of training, mice can solve a four-element sequential lockbox task that combines a lever, a stick, a ball, and a sliding door. Here, we present ongoing work across different lockboxes and species. We transfer the sequential lockbox task previously used in mice to rats, and develop a new lockbox for mice. The latter is a sensorized sliding lockbox with 99 tiles that can be moved in up to four directions, allowing multiple task solutions. By blocking a subset of tiles and then repositioning the blocked tiles across different task phases, the sliding lockbox allows us to test how an animal adapts to a new task. Both mice and rats are presented with the lockboxes in a lockbox cage that is part of their housing environment. They are trained over multiple task sessions, and their interaction with the lockboxes is captured by five cameras fixed around the lockbox cage. Manual and automated analyses of the resulting videos will be essential for quantifying the animals’ cognitive performance and understanding their cognitive strategy. Behavioral and physiological measures will be collected to evaluate the effects of the lockbox cognitive stimulation. The rat experiments will be performed in adult females and males, thereby providing important information on possible sex differences.