Binge eating for sucrose is time of day dependent and independent of food restriction: Effects on mesolimbic structures.

Binge eating behavior (BEB) is the most common condition among eating disorders. In animal models, binge eating behavior is defined as overconsumption in a brief time interval and it develops as a progressive increase in food intake along time. It is triggered by restricting food access to regular chow or to palatable food and is associated with dopamine release from the ventral tegmental area to the nucleus accumbens. The dopamine system, exhibits day-night patterns, suggesting regulation by the circadian system. This study explored in rats the differential contribution of restricted food access to chow and sucrose for developing BEB, it explored whether BEB exhibits a day-night pattern, and whether behavioral changes are associated with the number of tyrosine hydroxylase (TH) positive cells in the ventral tegmental area, with the expression of dopamine 1 receptors (D1) and glutamate receptor subunit 1 receptors (GLUR1) in the nucleus accumbens. Present data indicate that under conditions of restricted access binge eating is developed for chow or sucrose. Both types of binge eating were independent of each other and exhibited a day-night pattern with increased intensity during the active phase (night). Binge eating was preceded by anticipatory activation, except when restricted food access was given during the day. Increased optical density for D1 receptors was found after exposure to the combination of restricted food access and sucrose. No association was observed between binge eating and the number of positive cells to TH in the ventral tegmental area, nor for GLUR1 in the nucleus accumbens. Present results point out the importance of time schedules to eat, highlighting an increased vulnerability to develop binge eating during the active phase. (PsycInfo Database Record (c) 2020 APA, all rights reserved).