Pharmacological manipulation of binge-like eating in male and female rats.

Abstract

Binge Eating is characterized by recurrent episodes of eating large amounts of food in short periods of time. Animal models of binge-like eating (BLE) are essential for interrogating the brain systems underlying binge eating. Intermittent and limited access to highly palatable food in rats promotes a binge-like escalation of food intake. The first experiment focused on the development of BLE in non-food restricted male and female rats induced by brief, random exposure to different food types (chocolate, high carbohydrate pellets, grain pellets). Male and female rats showed significant induction of chocolate intake compared to high carbohydrate and grain pellets over 12 exposure sessions, with females eating more food than males in the BLE sessions, especially the chocolate, despite having a lower body weight. The amphetamine prodrug lisdexamfetamine (0.1875-1.5 mg/kg IP), which is used to treat binge eating disorder in humans, suppressed intake of all foods in both sexes, with the greatest effects on chocolate. Co-administration of dopamine receptor antagonists with varying selectivity profiles (ecopipam, haloperidol, flupenthixol) reversed the suppressive effects of LDX on binge-like intake of chocolate, with haloperidol and flupenthixol producing more robust effects. The final group of studies characterized the effects of two commonly prescribed drugs for weight-loss that have been suggested as treatment options for binge eating disorder (bupropion and naltrexone). These drugs, alone and in combination, suppressed binge-like intake of chocolate. Taken together, these findings contribute to the development of animal models of BLE, which can potentially foster the development of treatments for binge eating disorder.