An animal model for the study of binge-like eating episodes preceded by frustration events in females and non-food deprived animals

Introduction

Previous data from our laboratory show that frustration events could function as an important factor in the etiology and maintenance of the binge-like eating episodes. However, in previous experiments, male Wistar rats deprived of food were used. This reduced the external validity of the phenomenon as an animal model of binge-eating episodes since they are more prevalent in women and can occur without prior energy deficit.

Objective

To explore the presence of increased intake after a previous frustration event in two new experimental conditions: male rats without food deprivation (experiment 1) and female rats with food deprivation at 83% of their ad libitum weight (experiment 2).

Method

The animals had access to a 32% sweetened solution during five daily trials of five minutes each. During the trials 6, 8 and 10, half of the animals received the reinforcer normally, and the other half after a delay of 10 min. In the trials 7, 9 and 11 all animals received the reward without prior delay.

Results

The model was replicated in the two experiments.

Discussion

These data generalize our previous observations to two novel conditions, one sexual and the other motivational, which results in an increase in its external validity.