An Investigation of the Effect of Vicarious Social Defeat Stress on Stress Hormones and Food Consumption in Male Mice

In addition to causing depressive-like behaviours in rodents, stressors can also alter feeding behaviour and body weight. The current study aimed to investigate the vicarious social defeat stress model as a means of studying the effects of stressors on feeding, in a manner that allows for comparison between directly affected victim animals and witnesses to social defeat. Increased corticosterone secretion occurred in both acutely treated victim and witness animals 10 minutes following stressor exposure, an effect that persisted in the victim animals for 1.5 hours. No significant effects were found in chronically treated groups, which may be the result of a habituation-like effect to repeated stressor exposures. No significant changes were found in food consumption, weight gain, or plasma ghrelin. Overall, these findings shed light on the impact of social stressors and the consequences of being involved in, compared to witnessing, social defeat.