Stressed Mice Alter Caloric Preference for Carbohydrate Rich Diets: The Role of Ghrelin During Stress

Under chronic social stress conditions, mice show a preference for carbohydrates. In this present thesis we hypothesize that this behavior is critical for blunting the stress response and that ghrelin contributes to this change in preference. Using the chronic social defeat stress paradigm, we showed that stressed mice increase their total caloric intake, particularly the intake of carbohydrate rich diets and sucrose solutions over palatable high fat diets. Furthermore, mice that are prevented from increasing their caloric intake show exaggerated hormonal responses to the social stressor.Finally, mice with mutations to the ghrelin receptor gene (GHSR KO) do not show increased caloric intake and show more depressive like symptoms in spite of increasing their consumption of a sucrose solution. This data suggests that stress increases the intake of carbohydrate rich foods to attenuate the endocrine response to social stress and that ghrelin plays an important role in this process.