Scoring Methods of Aggression in Murine Models of Aggression and Social Defeat

Abstract

Aggression is a diverse set of attack behaviors that manifest to confer survival during competition, in response to fear, or as a pathological neuropsychiatric condition. In a laboratory context, rodent aggression behavior is studied to better understand human violence and as a component of models that use aggression as a stressor to induce clinically relevant neuropsychiatric phenotypes. Preclinical rodent aggression research has historically focused on inter-male aggression, but emerging work demonstrates that rival female aggression can be studied and applied in stress paradigms to better understand sex differences in biomedical research. In rodent models, aggression is typically studied using the resident–intruder task, which can be adapted for the study of different forms of excessive aggression, but there are several challenges to aggression measurement. Principal among these challenges is the lack of standardization in aggression measurement, preventing comparison and replication of work across laboratories. However, recent work using mathematical models derived from hundreds of experiments provides a high-throughput data-driven approach to calculating a composite aggression score. In the future, the emerging field of self-administration of aggressive encounters will allow the study of the rewarding and appetitive aspects of aggression in a standardized and quantifiable manner.