Modelling disordered eating behaviour in rats and mice

Eating disorders and drug addiction share many common traits, including biological and environmental factors that predispose individuals to developing disordered behaviour. Individuals with both disorders also have an increased risk for anxiety and depression and heightened levels of impulsivity and compulsions. This overlap is not surprising considering drugs of abuse activate neural reward systems that have evolved to reinforce certain behaviours, such as feeding, that enhance the individual’s ability to survive. Animal models of eating disorders are not as well established as those that model drug addiction, but the experimental paradigms used to assess common features are beginning to be applied to understand the neurobiological underpinnings of common eating disorders such as anorexia nervosa (AN), binge eating disorder (BED) and obesity, as well as other less widely studied disorders like avoidant restrictive food intake disorder (ARFID). The focus of this project is to understand the complex behaviours that govern disordered feeding in rats and mice and the involvements of reward, cognitive and homeostatic brain pathways in these behaviours. To this end, we utilize traditional and automated behavioural testing paradigms in combination with light- and drug-based approaches (optogenetics and chemogenetics) to manipulate neuronal activity. We use in vivo fiber photometry to measure how brain activity changes in response to changing metabolic demands and across learning paradigms. We are also interested in developing novel methods to assess disordered feeding behaviour in rats and mice with a focus on individual differences and biological variation as well as social, environmental and emotional factors.