Behavioral and pharmacological characterization of a mouse model of palatable diet alternation

Abstract

Obesity and eating disorders represent a severe problem in Western societies. Both the increased availability of highly palatable foods and dieting are major risk factors contributing to the epidemic disorders of feeding. The purpose of this study was to characterize an animal model of maladaptive feeding induced by intermittent access to a palatable diet alternation in mice. In this study, mice were either continuously provided with standard chow food (Chow/Chow), or provided with standard chow for 2 days, with 1 day of access to a high-sucrose, palatable food (Chow/Palatable). Following stability of intake within the cycling paradigm, we investigated the effects of several pharmacological treatments: Naltrexone, an opioid antagonist, SR141716A (rimonabant), a type 1 cannabinoid receptor antagonist, and BD-1063, a type 1 sigma receptor antagonist. Over successive cycles, Chow/Palatable mice showed an escalation of palatable food intake within the first-hour of renewed access to palatable diet, and displayed hypophagia upon its removal. Naltrexone, SR141716A, and BD-1063 reduced overconsumption of palatable food during this first hour. Here we provide evidence of strong face and convergence validities in a palatable diet alternation model in the mouse, confirming multiple shared underlying mechanisms of pathological eating across species, and thus making it a useful therapeutic development tool.