Peripheral oxytocin cut binge eating and compulsive-like behavior in male rats by restructuring satiety

Binge-type eating is a significant public health concern, often driven by highly palatable foods, leading to excessive intake and compulsive behaviors. Current treatments often have limited efficacy or side effects. Oxytocin is a neuropeptide known to regulate food intake and energy balance, with prior evidence suggesting it reduces carbohydrate intake and motivation for palatable foods. However, its direct impact on binge size and the specific behavioral mechanisms underlying its effects on palatable food consumption in a binge model remained unclear. This study aimed to elucidate these aspects.

Male Wistar rats were subjected to an intermittent palatable food (high sugar) access model over four weeks to induce binge-type eating. After establishing binge criteria, rats received oxytocin (1 mg/kg, i.p.). Food intake and parameters of the Behavioral Satiety Sequence (BSS) were measured in the home-cage. Subsequently, compulsive-like eating behavior was assessed following the same dose of oxytocin in an aversive/anxiogenic open field.

Peripheral oxytocin (1 mg/kg, i.p.) significantly decreased the binge size for palatable food in male Wistar rats. Behavioral analysis revealed that oxytocin increased time spent resting and reduced initial food consumption. This suggests a direct impact on the immediate post-ingestive behaviors. The observed changes in feeding patterns were profound, indicating a shift in the typical progression of satiety. These findings highlight oxytocin's ability to modulate not just the quantity of food consumed, but also the qualitative aspects of the feeding experience. The study's behavioral assessments provided a comprehensive view of oxytocin's effects on complex eating behaviors. The findings suggest a potential role for oxytocin in re-establishing healthier eating patterns by influencing both the initiation and termination of feeding. The observed effects were consistent across different behavioral paradigms, reinforcing the robustness of oxytocin's impact on binge-type eating. The study also explored the impact of oxytocin on stress-induced eating behaviors. In the aversive/anxiogenic open field, oxytocin administration increased the latency to eat and decreased overall food intake, indicating a reduction in compulsive-like eating behavior under challenging conditions. These findings suggest oxytocin not only curtails binge episodes but also fundamentally alters the physiological and behavioral cues associated with satiety and food-seeking under stress. The observed effects on satiety and compulsive behavior point towards a multifaceted mechanism of action for oxytocin in this model. The study's detailed behavioral analysis provides valuable insights into how oxytocin might exert its therapeutic effects. The consistent reduction in binge size and compulsive behaviors across different measures underscores the potential of oxytocin as an intervention. The findings also suggest that oxytocin could be influencing central pathways involved in reward and motivation, beyond simple appetite suppression. The study's results are particularly relevant for understanding the neurobiological underpinnings of binge eating. The observed changes in the BSS are a key indicator of altered satiety signaling. The reduction in compulsive-like eating further supports oxytocin's broad impact on maladaptive feeding behaviors. The study's design allowed for the assessment of both ad libitum feeding and stress-induced eating, providing a comprehensive picture of oxytocin's effects. The findings are consistent with previous research suggesting a role for oxytocin in social and emotional regulation, which can indirectly influence eating behaviors. The study's robust behavioral data supports the conclusion that oxytocin has a significant impact on binge-type eating. > This intervention disrupted the normal Behavioral Satiety Sequence (BSS) structure, which typically involves an orderly transition from eating to resting/sleeping, and paradoxically promoted a late onset of satiety. Furthermore, in an aversive/anxiogenic open field, oxytocin administration increased the latency to eat and decreased overall food intake, indicating a reduction in compulsive-like eating behavior. These findings suggest oxytocin not only curtails binge episodes but also fundamentally alters the physiological and behavioral cues associated with satiety and food-seeking under stress.