Pharmacological and neural control of anti-predator defense in the rat

Abstract

An ethoexperimental analysis of the defensive behaviors of laboratory and wild rats to predators can predict specific defense patterns in terms of features of the threatening stimulus and the situation. This analysis suggests that a variety of specific defenses, such as flight, movement arrest, and defensive threat and attack, are most characteristic of fear to a present, discrete, threat stimulus while risk assessment patterns coupled with the inhibition of nondefensive behavior are the central features of anxiety to potential threat. In a Fear/Defense Test Battery (F/DTB) and an Anxiety/Defense Test Battery (A/DTB) designed to elicit and measure such behaviors, benzodiazepines, 5-HT1A agonists, and ethanol produced very different behavior profiles, with diazepam in particular having relatively little effect in the F/DTB but sharply and specifically reducing risk assessment in the A/DTB. The specific defensive behaviors for which neuroanatomic and neurochemical substrates have been sought appear to show substantial differences. These analyses suggest that defense comprises a number of systems which can be differentiated on stimulus, organismic, and response (behavioral) dimensions. The potency of these reactions and their elicitation by a wide variety of threatening stimuli and situations suggest that they may appear in human as well as animal behavior, with the animal models providing homologies to a variety of human psychopathological conditions.