Attack and defense in rodents as ethoexperimental models for the study of emotion

1. In wild and laboratory rats, offense and defense constitute nonoverlapping behavior patterns seen in response to resource or dominance challenge, or, to predatory, conspecific or environmental threat, respectively. 2. Defensive behaviors are determined by both the threat stimulus and the situation. Defense patterns to discrete, approaching, predators or conspecifics and to nondiscrete, potential, threat have several behaviors in common. However, the latter also includes an important risk assessment complex not seen to discrete, present, threat. Behaviorally and functionally, risk assessment shows considerable similarity to the apprehensive expectation and vigilance and scanning components of generalized anxiety reactions. 3. There are parallels between lower mammal offense and human angry aggression in terms of eliciting stimuli, and a variety of experiential factors including inhibition by fear/pain, and reinforcement effects. 4. A variety of neuroanatomical or pharmacological manipulations have different, often opposite, effects on offense and defense. Differentiation of the two and attention to the specific behaviors involved provide a more precise basis for the use of these patterns as animal models of emotion states.