Limitations in animal model for anxiety disorders: A scientific analysis

Abstract

Developing an animal model for thought-based disorders like anxiety is an uphill battle in scientific community. More than the face and construct validity, the predictive validity is heavily relied to validate the animal model for anxiety disorders in rats. Among the various conditioned and unconditioned animal models for anxiety disorders, ethological based models like predator encounter is reported to have high validity and reliability because the defensive reactions against predator is largely instinct. For these instinct behaviours to express certain key environmental needs coinciding with their ethology should be provided during the rat developmental stages and their requirement for wellbeing should be studied from their wild conspecifics. But as the architect of the animal house being humans, they mostly extend their comfort to the animals. As a result, the conventional designed cages have provisions of enhanced day light availability, ambient temperature regulation with air coolers normally present in animal house. Additional drawback for the development of animal model for anxiety is the maze design itself. The standard procedure involves studying the rat behaviour in a fixed maze of a particular geometric design. Most mazes design constraint the rat ethology and only explore to what extend the animal is accepting the things normally to be avoided e.g., light chamber entry in the light dark box and open space entry in the elevated plus or zero maze. This review presently discourses the importance of these limitations and the way it will influence the development of animal model for anxiety disorders.