Prelimbic Cortex Deep Brain Stimulation Reduces Binge Size in a Chronic Binge Eating Rat Model

Abstract

Background: Binge eating (BE) involves the consumption of a large amount of food in a short period of time and a loss of control during the binge episode. It is a key feature of the major subtypes of eating disorders like bulimia nervosa, BE disorder, anorexia nervosa binge/purge type. Alterations in the mesocorticolimbic pathway play a crucial role in its pathophysiology. Objectives: We hypothesized that BE rats receiving deep brain stimulation (DBS) in the prelimbic cortex, a functional analog of the dorsolateral prefrontal cortex in humans, would have a reduced binge size compared with those receiving sham stimulation. Methods: Eight male Sprague-Dawley rats were implanted with a DBS electrode in the left prelimbic cortex. A protocol which included limited access to a “sweet-fat” diet was used to achieve a chronic BE state in the rats. After reaching a stable binge size, each rat had undergone sham, low-frequency stimulation (60 Hz), and high-frequency (130 Hz) stimulation for 3 sessions each, and 2 consecutive treatments were separated by at least 2 empty sessions to allow a washout of the effects. A one-way ANOVA was used for the data analysis. Results: Low-frequency (60 Hz) stimulation of the prelimbic cortex significantly reduced the binge size compared to the sham stimulation (p < 0.0001). High-frequency DBS (130 Hz) had no significant influence on this behavior when compared to sham stimulation (p = 0.9). Conclusions: This study suggests that low-frequency prelimbic cortex stimulation in BE would be useful for correcting prefrontal hypofunction which is strongly associated with BE and addiction pathogenesis.