Effect of restraint stress on food intake and body weight is determined by time of day

Abstract

Three experiments were conducted to investigate the effect of restraint stress applied at different times of the light-dark cycle on feeding behavior and body weight of rats. Sprague-Dawley rats were restrained for 3 h in restraining tubes either at the start or the end of the light cycle. There was a significant reduction in food intake on the day of restraint and no change in food intake during a 10-day recovery period in either experiment. Reductions of food intake on the day of restraint were about the same for both restrained groups compared with their controls. When stress was applied in the evening, eating was inhibited during the first 2 h after restraint, whereas in rats restrained in the morning, feeding was suppressed twice: during the 4 h after restraint and during the first 2 h of the dark cycle. Restraint induced a significant weight loss that was greater in the rats stressed in the morning. Neuropeptide Y (NPY) levels determined at the time of food suppression for both experiments (beginning of the dark cycle) revealed an elevation of NPY in the paraventricular nucleus of rats stressed in the morning compared with other groups, but no difference in hypothalamic NPY mRNA expression. Expression of uncoupling protein mRNA in brown adipose tissue and leptin mRNA in epididymal fat, measured at the start of the dark period, was not altered by stress. There was an elevation of dopamine turnover in the hypothalami of rats restrained at the end of light cycle, but not those restrained in the morning. These results show that restraint stress has a greater effect on metabolism and energy balance when it is applied in the morning. Additional studies are needed to elucidate mechanisms involved in the suppression of food intake 9 h after restraint.

Domestication effects on behavioural and hormonal responses to acute stress in chickens

“…In females, feeding and drinking differed significantly between the breeds over time, where RJF showed an immediate behaviour change followed by a fairly rapid return to baseline, while the effects were more subtle in WL. In rodents, decreased feeding can be caused by both repeated [35] and acute stress [38], and time to retain normal feeding has been found to vary dependent on type and intensity of the stressor [33,38,48]. Foraging behaviour in the WL did not revert to baseline during the entire hour after stress, while in RJF it did so faster, and even increased over baseline after 10-15 minutes.…”

“…This allowed us, for the first time, to assess effects of domestication on behavioural and endocrine stress responses in chickens. In particular, we focused on the recovery process and the return to normal levels of both behaviour and concentrations of the steroids, using a similar approach as in earlier research on stress recovery [33][34][35][36][37][38][39][40].…”

Time matters: pathological effects of repeated psychosocial stress during the active, but not inactive, phase of male mice

“…This, in turn, would lead to differential consequences of chronic/ intermittent stressor exposure, in terms of both outcome and severity, for an individual. In support, the few studies that have examined this hypothesis have shown that restraint stress has different effects on body weight development and adrenal gland weight, depending on the time of day of stressor exposure (Rybkin et al (1997) and Perez-Cruz et al (2009), for review, see Koolhaas et al (2011)). …”

Dynamic body weight and body composition changes in response to subordination stress

“…Stress is well known to produce changes in body weight in animal models as well [8][9][10][11][12][13][14][15][16]. In non-human primates, exposure to psychosocial stress results in reduced negative feedback regulation of cortisol secretion, suppression of the hypothalamic-pituitary-gonadal (HPG) axis and reproduction, and increased depressive behavior [17,18].…”