Waiting for reward: an animal model for studying binge-like behavior

MATÍAS SERAFINI; LUCAS CUENYA; MICAELA LAURITO; CONSTANZA ILARRAZ

Mar del Plata

Congreso; 22do Congreso anual de la Sociedad Argentina de Investigación en Neurociencias; 2017

Sociedad Argentina de Investigacíón en Neurociencia

Increasing the intake of highly palatable food in a short time is one of the most important features of binge eating episodes. These are usually related to the previous experimentation of negative emotions. The objective of this study was to explore some aspects of binge eating behavior in a new animal model that involve exposure to frustrating events due to the delay of an expected reinforcement. Adult male Wistar rats were used. In Experiment 1 it was observed that animals trained to receive a highly palatable reinforcer (32% sucrose solution) express a significant intake increase if they are re-exposed to the reward after a 2 min delay, as compared to a control group without delay. In Experiment 2 we explored whether the magnitude of the intake increase is dependent on the state of frustration. Specifically, a group of animals were evaluated upon re-finding a 16% sucrose solution after a delay, which represents a less stressful condition since the discrepancy between the obtained and expected reward is lower. The effect of increased intake by delayed reinforcement was replicated in animals trained with 32%, while no increase intake was observed in animals trained with 16%. These data suggest that the state of frustration produced by delayed reward would involve an increase in the motivational value of the expected reward. This could be one of the behavioral mechanisms underlying the intake increase after frustrating situations.