Interaction between repeated restraint stress and concomitant midazolam administration on sweet food ingestion in rats

Abstract

Emotional changes can influence feeding behavior. Previous studies have shown that chronically stressed animals present increased ingestion of sweet food, an effect reversed by a single dose of diazepam administered before testing the animals. The aim of the present study was to evaluate the response of animals chronically treated with midazolam and/or submitted to repeated restraint stress upon the ingestion of sweet food. Male adult Wistar rats were divided into two groups: controls and exposed to restraint 1 h/day, 5 days/week for 40 days. Both groups were subdivided into two other groups treated or not with midazolam (0.06 mg/ml in their drinking water during the 40-day treatment). The animals were placed in a lighted area in the presence of 10 pellets of sweet food (Froot loops ® ). The number of ingested pellets was measured during a period of 3 min, in the presence or absence of fasting. The group chronically treated with midazolam alone presented increased ingestion when compared to control animals (control group: 2.0 ± 0.44 pellets and midazolam group: 3.60 ± 0.57 pellets). The group submitted to restraint stress presented an increased ingestion compared to controls (control group: 2.0 ± 0.44 pellets and stressed group: 4.18 ± 0.58 pellets). Chronically administered midazolam reduced the ingestion in stressed animals (stressed/ water group: 4.18 ± 0.58 pellets; stressed/midazolam group: 3.2 ± 0.49 pellets). Thus, repeated stress increases appetite for sweet food independently of hunger and chronic administration of midazolam can decrease this behavioral effect.

Influence of Housing Conditions on the Effects of Serotonergic Drugs on Feeding Behavior in Non-Deprived Rats

“…These anxiogenic properties of isolation have been attributed to the activation of 5-HT1A somatodendritic receptors, since they are enhanced by acute gepirone and reversed by chronic gepirone. Our results are in line with findings from studies using restraint stress [19,20], and some studies in humans have also provided evidence of hyperphagia induced by emotional experiences [21]. However, it must be borne in mind that effects of emotional alterations on feeding behavior are dependent on the type and severity of the stressor [22,23].…”

“…It would be expected that the combination of isolation stress and gepirone would increase the hyperphagic effect of gepirone, since there is evidence that restraint stress also increases ingestion of food in animals. These effects have also been claimed to be related to anxiety, since they could be reversed by benzodiazepines [19,20]. Thus, in this study, we examined the effects of daily treatment with these drugs during three weeks in isolated and group-housed animals.…”

Aircraft noise exposure affects rat behavior, plasma norepinephrine levels, and cell morphology of the temporal lobe

“…1a, we also know that line crossing of rats was not significantly different between CG and EG-II except on the 8th day. The reason is that behaviors of rats manifest itself differently depending on the duration of stress (Silveira et al, 2000). Conrad et al (1999) have also shown that behaviors of rats turned from an excited state to inhibitory state under prolonged stress.…”

Na+, K+ ATPase Activity Is Reduced in Amygdala of Rats with Chronic Stress-Induced Anxiety-Like Behavior

“…In UCMS models, rats are exposed to different weak stressors for several days. The absence of predictability concerning the stressor applied is an important characteristic of this model, and may be related to the different effect observed in these animals when compared to other models, in which repeated stress is used and a higher consumption of sweet food is observed [32,57]. Thus, we also submitted the animals to predictable CRS to analyze possible differences.…”