Conditioned food aversion: A strategy to study disordered eating?

Abstract

Multiple eating disorders show dramatic onsets during childhood or adolescence, and involve conditioned avoidance to previously accepted foods. Anorexia Nervosa (AN) has the highest fatality rate of any psychiatric disorder. Currently, animal models of the disease focus on anorexia associated with food restriction, extreme stress, and/or excess physical activity. No model captures the disease’s key characteristics of visceral hypersensitivity leading to learned food avoidance, adolescent onset, and female dominance. Avoidant/Restrictive Food Intake Disorder (ARFID) is slightly more prevalent in males, appears earlier developmentally, and in some cases may transition into AN. The purpose of this study was to evaluate sex and age differences in conditioned taste/food aversion (CTA, CFA) to determine if sex differences and ontogenetic pattern resembles either of these two important eating disorders, and to examine developmental changes in CTA relevant to their onset. The results demonstrate that adolescent females already exhibit adult-typical conditioned taste/food aversion, while marked changes occur in males from adolescent insensitivity to marked adult sensitivity to CTA/CFA. These results suggest that rodents could provide a feasible model to study the development of neural circuits relating to the appearance of AN in females, but may be less relevant to ARFID in males. This study aimed to develop a new rodent model for disordered eating that more accurately reflects certain human phenotypes, such as gut hypersensitivity, self-imposed food restriction, female dominance, and adolescent onset. By studying the behaviors and brain activations and development associated with this model, we aimed to gain a greater understanding of the biological mechanisms and vulnerability markers for disordered eating. Understanding these biological aspects will both help to de-stigmatize patients and families suffering from the effects of eating disorders and may lead to the development of better treatments for disorders such as Anorexia Nervosa and ARFID.