Effects of Lisdexamfetamine and Haloperidol on a Binge-Like Eating Model & Preliminary Investigations of the Dopaminergic Mechanism Underlying Binge Eating Disorder (BED)

Binge eating disorder (BED) is a psychophysiological disorder defined as the excessive intake of high-caloric, palatable foods within a short span of time, accompanied by feelings of distress. Animal models of binge-like eating behavior have been developed that give intermittent, limited access to a highly palatable food. Presby et al. (2020) used chocolate as the highly palatable food to induce binge-like eating behavior in rats. Lisdexamfetamine (LDX), a d-amphetamine prodrug and dopamine (DA) uptake inhibitor, is currently used to treat BED in humand. In rats, binge-like eating of chocolate was induced by exposure to unpredictable and limited chocolate access over several weeks. After training, rats were tested for the effects of LDX and the DA D2 antagonist haloperidol in one-hour chocolate exposure sessions. Consistent with previous results, the highest doses of LDX (0.75 and 1.5 mg/kg IP) suppressed chocolate intake. In contrast, doses of haloperidol (0.05-0.1 mg/kg IP) did not significantly affect chocolate consumption. Furthermore, haloperidol partially reversed the LDX-induced decrease in chocolate consumption. These results have implications for understanding the role of DAergic mechanisms in the regulation of binge-like eating. One hypothesis for this reduction involves increases in mesolimbic DA but more classic literature regarding the anorexic effects of amphetamines, such as LDX, identifies the perifornical lateral hypothalamus (PFH) as a critical brain region responsible for driving a reduction in food intake. This study observed the effects of LDX and haloperidol on the binge-like consumption of chocolate as well as the DAminergic mechanism of LDX in the PFH through microdialysis and high-performance liquid chromatography. These results have implications for the further understanding of mechanisms underlying binge eating behavior as well as improved knowledge of treatment for BED patients