Estrogenic suppression of binge‐like eating elicited by cyclic food restriction and frustrative‐nonreward stress in female rats

Abstract

Objective Because binge eating and emotional eating vary through the menstrual cycle in human females, we investigated cyclic changes in binge-like eating in female rats and their control by estrogens. Method Binge-like eating was elicited by three cycles of 4 days of food restriction and 4 days of free feeding followed by a single frustrative nonreward-stress episode (15 min visual and olfactory exposure to a familiar palatable food) immediately before presentation of the palatable food. Results Intact rats showed binge-like eating during the diestrous and proestrous phases of the ovarian cycle, but not during the estrous (peri-ovulatory) phase. Ovariectomized (OVX) rats not treated with estradiol (E2) displayed binge-like eating, whereas E2-treated OVX rats did not. The procedure did not increase signs of anxiety in an open-field test. OVX rats not treated with E2 that were subjected to food restriction and sacrificed immediately after frustrative nonreward had increased numbers of cells expressing phosphorylated extracellular signal-regulated kinases (ERK) in the central nucleus of the amygdala (CeA), paraventricular nucleus of hypothalamus (PVN), and dorsal and ventral bed nucleus of the stria terminalis (BNST) compared with non-restricted or E2-treated rats. Discussion These data suggest that this female rat model is appropriate for mechanistic studies of some aspects of menstrual-cycle effects on emotional and binge eating in human females, that anxiety is not a sufficient cause of binge-like eating, and that the PVN, CeA and BNST may contribute to information processing underlying binge-like eating.

Transcriptional regulation of the endocannabinoid system in a rat model of binge‐eating behavior reveals a selective modulation of the hypothalamic fatty acid amide hydrolase gene

“…On day 25, the final test day, each group was exposed or not to stress (15 min) (see Figure 1 for details). We found in a previous study that stress-induced BE in our model is not observed during the estrous phase (Alboni et al, 2017;Micioni Di Bonaventura, Lutz et al, 2017). In these conditions, the animal was able to see the cup and the palatable food itself and could smell its odor.…”

Hypothalamic CRF1 receptor mechanisms are not sufficient to account for binge‐like palatable food consumption in female rats

“…The amygdala and BNST are brain regions anatomically and functionally connected (de Olmos & Heimer, 1999) and the amygdala is known to have CRF-containing projection to the BNST (Erb, Salmaso, Rodaros, & Stewart, 2001) and in particular CeA has emerged as an important area in the regulation of excessive consumption of palatable food (Blasio et al, 2013; de Olmos & Heimer, 1999; Iemolo et al, 2013; Micioni Di Bonaventura et al, 2017). The observation that blockade of CRF receptors in these brain areas completely reversed stress-induced binge eating in our model indicates a critical role of extrahypothalamic CRF systems.…”

“…This stress procedure has face validity as a model of the putative contributions of dieting and negative-valence states, to binge eating in humans (Association, 2013; Mathes, Brownley, Mo, & Bulik, 2009; Sanislow et al, 2010; Treasure, Claudino, & Zucker, 2010; Vannucci et al, 2015). Considering the high prevalence of binge eating in women (Hudson et al, 2007; Swanson et al, 2011), we used female rats, in which binge-like eating behavior varies across the estrus cycle (Alboni et al, 2017; Micioni Di Bonaventura et al, 2017), similarly to women (Culbert, Racine, & Klump, 2016; Edler, Lipson, & Keel, 2007; Klump et al, 2013; Schoofs, Chen, Braunig, Stamm, & Kruger, 2011) and this result increases the validity of the model that can be used in translational studies of the mechanism of binge eating behavior.…”

The duration of intermittent access to preferred sucrose-rich food affects binge-like intake, fat accumulation, and fasting glucose in male rats

“…Thus, an interpretation relevant to negative results in the exploration-based anxiety models is that the motor arousal may reflect food-seeking behavior. In this interpretation, the recent (2h) or otherwise expected availability (4h and 8h groups) of palatable food might supersede the anxiogenic-like plus-maze and defensive withdrawal environments, leading to food-seeking behavior despite the threat of open spaces (Micioni Di Bonaventura et al, 2017; Parylak et al, 2012). Such a result was seen in open-field conflict reinstatement tests(Dore et al, 2014; Teegarden & Bale, 2007).…”