Measuring Mood in Rodents

Abstract

Mood disorders - depression in particular - affect a large percentage of the population and account for a large part of worldwide burden both on a health and economic basis. Animal models are essential for expanding scientific knowledge of these disorders as they allow for specific and precise manipulations of the brain that are not possible in humans. However, because of the complexity and individual variability of depression, developing and assessing appropriate animal models is a major challenge. To further understand the causes of this variability, there has been an increased interest in the neurological underpinnings of the illness. This review will discuss the techniques used to assess and measure depression-like phenotypes in animals as well as models of the illness and tasks used to measure behavioural phenotypes. There has been increasing precision and sophistication in the development of animal models, from lesion to transgenic models, and advances in tasks from basic aversive tasks to more advanced touchscreen tasks. This review explores the use of animal models for depression and argues that touchscreen tasks may be better suited for assessing and measuring depression-like behaviour in rodent models as these tasks are less aversive, more translatable, and potentially more powerful in detecting subtle differences across treatment groups.