Intermittent access to sugary drinks associated with fasting induces overeating and depressive-like behavior in female C57BL/6J mice

Abstract

Binge eating disorder is the most prevalent eating disorder, affecting both sexes but more commonly found in women. Given the frequent co-occurrence of psychiatric disorders, this study aimed to establish a standardized experimental intermittent protocol to investigate overeating associated with depression. A 10-day protocol induced uncontrolled eating behavior in C57BL/6J female mice. The first experiment included the following groups: naive group (chow ad libitum), control group (chow and sucrose solution ad libitum), and fasting groups (16 and 20 h) exposed to an intermittent sucrose solution (10 %) and chow regimen. Subsequently, the feeding test, open field test, elevated plus maze test, tail suspension test, and light/dark conflict test were conducted. Furthermore, monoamine oxidase (MAO) A and B activities in brain structures and plasma corticosterone levels were assessed. Food overconsumption and depressive-like behavior were observed in both sucrose fasting groups, while risk-taking behaviors were specifically observed in the 20-hour fasting sucrose group. While both fasting sucrose groups caused reduced hippocampal MAO-A activity, only the F20 sucrose group inhibited MAO-B in the cortex and hypothalamus. Moreover, both fasting sucrose groups exhibited elevated corticosterone levels. In a separate design (Experiment 2), groups with 16 and 20 h of fasting alone (without sucrose) did not show the same behavioral results as the intermittent fasting sucrose groups, thus avoiding fasting bias. Based on these results, the 20-hour sucrose fasting group was chosen as the ideal protocol for mimicking overeating behavior associated with depression to investigate future therapeutic approaches for this comorbidity.