Relapse to maladaptive eating habits during dieting is often provoked by stress or acute re-exposure to palatable foods. Until recently, this clinical problem was not systemically addressed in animal models. To address this issue, we recently adapted a rat reinstatement model (commonly used to study relapse to drugs of abuse) to study relapse to palatable food seeking induced by food priming (non-contingent exposure to small amounts food pellets) or injections of yohimbine (a prototypical alpha-2 adrenoceptor antagonist that causes stress-like responses in humans and non-humans). Here, we assessed the predictive validity of the food reinstatement model by studying the effect of the serotonin releaser fenfluramine on reinstatement of food seeking. In humans, fenfluramine is an effective dietary treatment that decreases food intake and body weight. We trained food-restricted female rats to lever-press for 45 mg food pellets (3-h sessions) and first assessed the effect of fenfluramine (1.5 and 3.0 mg/kg, i.p.) on food-reinforced responding. Subsequently, we extinguished the food-reinforced responding and tested fenfluramine’s effect on reinstatement of food seeking induced by yohimbine injections (2 mg/kg i.p.) or pellet priming (4 non-contingent pellets). Fenfluramine decreased yohimbine- and pellet priming-induced reinstatement in a dose-related manner. As expected, fenfluramine also decreased food-reinforced responding, but control experiments indicate that fenfluramine’s effects on lever-presses are not due to performance deficits. The present data provide evidence for the predictive validity of the food reinstatement model and suggest that the model can be used to identify medications for prevention of relapse induced by stress or acute exposure to palatable food during dietary treatments.
Effect of Fenfluramine on yohimbine- and pellet priming-induced reinstatement of food seeking in female rats: Implications for the predictive validity of the reinstatement model
CIFANI, Carlo;
2011-01-01
Abstract
Relapse to maladaptive eating habits during dieting is often provoked by stress or acute re-exposure to palatable foods. Until recently, this clinical problem was not systemically addressed in animal models. To address this issue, we recently adapted a rat reinstatement model (commonly used to study relapse to drugs of abuse) to study relapse to palatable food seeking induced by food priming (non-contingent exposure to small amounts food pellets) or injections of yohimbine (a prototypical alpha-2 adrenoceptor antagonist that causes stress-like responses in humans and non-humans). Here, we assessed the predictive validity of the food reinstatement model by studying the effect of the serotonin releaser fenfluramine on reinstatement of food seeking. In humans, fenfluramine is an effective dietary treatment that decreases food intake and body weight. We trained food-restricted female rats to lever-press for 45 mg food pellets (3-h sessions) and first assessed the effect of fenfluramine (1.5 and 3.0 mg/kg, i.p.) on food-reinforced responding. Subsequently, we extinguished the food-reinforced responding and tested fenfluramine’s effect on reinstatement of food seeking induced by yohimbine injections (2 mg/kg i.p.) or pellet priming (4 non-contingent pellets). Fenfluramine decreased yohimbine- and pellet priming-induced reinstatement in a dose-related manner. As expected, fenfluramine also decreased food-reinforced responding, but control experiments indicate that fenfluramine’s effects on lever-presses are not due to performance deficits. The present data provide evidence for the predictive validity of the food reinstatement model and suggest that the model can be used to identify medications for prevention of relapse induced by stress or acute exposure to palatable food during dietary treatments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
