Animal models of anxiety disorders in rats and mice: some conceptual issues

Abstract

Animal models can certainly be useful to find out more about the biological bases of anxiety disorders and develop new, more efficient pharmacological and/or behavioral treatments. However, many of the current "models of anxiety" in animals do not deal with pathology itself, but only with extreme forms of anxiety which are still in the normal, adaptive range. These models have certainly provided a lot of information on brain and behavioral mechanisms which could be involved in the etiology and physiopathology of anxiety disorders, but are usually not satisfactory when confronted directly with clinical syndromes. Further progress in this field will probably depend on the finding of endophenotypes which can be studied in both humans and animals with common methodological approaches. The emphasis should be on individual differences in vulnerability, which have to be included in animal models. Finally, progress will also depend on refining theoretical constructs from an interdisciplinary perspective, including psychiatry, psychology, behavioral sciences, genetics, and other neurosciences.

Keywords: animal model; anxiety; coping strategy; defense; threat.

Figure 1.. Figure 1. Alternative defense (coping) strategies in response to threat. Depending on their psychobiobgical profile (temperament), previous experiences, appraisal of the situation, and/or environmental constraints, individuals can choose between an active fight-or-flight strategy, or a more passive, conservative-withdrawal response.If flight is not possible (“entrapment” situation, see ref 22) or aborted (“Arrested flight,” see ref 23), they have to rely on a passive coping strategy. The same occurs if, after fighting, they are defeated. Anxiety is markedly increased when the more passive coping strategies are used, or when action is inhibited, even momentarily (in choice and/or conflict situations). See text for details.