Evaluation of behavioural selection processes in conflict scenarios using a newly developed mouse behavioural paradigm.

Selecting an appropriate behaviour is critical for survival in conflict scenarios, wherein animals face both appetitive and aversive stimuli. Behavioural selection consists of multiple processes: (1) animals remain quiet in a safe place to avoid aversive stimuli (suspension), (2) once they decide to take risks to approach appetitive stimuli, they assess the risks (risk assessment), and (3) they act to reach the reward. However, most studies have not addressed these distinct behavioural processes separately. Here, we developed a new experimental paradigm called the three-compartment conflict task to quantitatively evaluate conflict processes. Our apparatus consisted of start, flat, and grid compartments. Mice needed to explore the grid compartment, where they might receive foot shocks while trying to obtain sucrose. Applying foot shocks increased sucrose acquisition latency in subsequent trials, reflecting elevated conflict levels throughout trials. The time spent in the start compartment and the number of retreats were determined to measure the conflict levels in suspension and risk assessment, respectively. Foot shocks increased these parameters, whereas diazepam decreased them. Our new paradigm is valuable for quantitatively evaluating distinct behavioural processes and contributes to developing effective treatments for psychiatric disorders associated with maladaptive behaviours in conflict scenarios.