Assessment of social defeat stress and feeding behavior in mice

Abstract

Background: Obesity is a global social and health problem, and one of the main factor is stress. Therefore, the study of how stress affects some physiological parameters is the basis of our study. Aim: Approve stress by changes in motor activity and some physiological parameters induced by social defeat stress. Material and methods: In our study, we used C57BL/6J mice bred in a controlled environment (control, acute and chronic 4 male mice each) and BALB/C male mice. Stress was performed according to a social defeat stress development method developed by Sam A Golden. The test mice (C57BL/6J) were kept in an aggressive (BALB/C) mouse cage for 10 min and then isolated for 90 min on a transparent plate with a light-penetrating hole. The experimental process was recorded on a HD video camera and the stress level was assessed using the DeepLabCut software. Blood was taken from the mouse’s tail and glucose was measured with a glucometer (Tyson Bio). Meals were measured daily before dark everyday.Two-tailed Student’s t-tests were used for analyses implicating two-group comparisons. Results: In the elevated plus maze test, the chronic (274.35±44.08 sec) and acute (220.76±15.81 sec) stress groups spent longer on the closed arm (p<0.05) compared to the control group (180.48±15.44 sec). After stress, the chronic (9.67 mml/L) and acute (8.9 mml/L) groups had statistically higher blood glucose levels (p<0.05) than the control group. In terms of food intake, acute stress group mice ate less food than the control group in 48 hours (p<0.05). The amount of food-intake of chronically stressed mice on the 16th day of the experiment was statistically significant (p<0.05). Conclusion: 1. Stress decreases the total distance traveled of experimental mice. 2. As a result of acute and chronic stress, blood glucose increases and acute stress reduces the amount of food-intake, and chronic stress increases the amount of food-intake.