Selective breeding of rats for high (HAB) and low (LAB) anxiety-related behaviour: A unique model for comorbid depression and social dysfunctions

Animal models of selective breeding for extremes in emotionality are a strong experimental approach to model psychopathologies. They became indispensable in order to increase our understanding of neurobiological, genetic, epigenetic, hormonal, and environmental mechanisms contributing to anxiety disorders and their association with depressive symptoms or social deficits. In the present review, we extensively discuss Wistar rats selectively bred for high (HAB) and low (LAB) anxiety-related behaviour on the elevated plus-maze. After 30 years of breeding, we can confirm the prominent differences between HAB and LAB rats in trait anxiety, which are accompanied by consistent differences in depressive-like, social and cognitive behaviours. We can further confirm a single nucleotide polymorphism in the vasopressin promotor of HAB rats causative for neuropeptide overexpression, and show that low (or high) anxiety and fear levels are unlikely due to visual dysfunctions. Thus, HAB and LAB rats continue to exist as a reliable tool to study the multiple facets underlying the pathology of high trait anxiety and its comorbidity with depression-like behaviour and social dysfunctions.

Automated summary

Animal models of selective breeding for extremes in emotionality are an important tool in studying psychopathologies. In this study, Wistar rats selectively bred for high and low anxiety-related behavior are extensively discussed. The study confirms the differences between high and low anxiety rats in trait anxiety, depressive-like behavior, social behavior, and cognitive behavior. The study also identifies a genetic factor causative for neuropeptide overexpression in high anxiety rats. These findings demonstrate that HAB and LAB rats are reliable models for studying high trait anxiety and its comorbidity with depression-like behavior and social dysfunctions.