In the present study we examined meal patterns during and after exposure to the visible burrow system (VBS), a rodent model of chronic social stress, to determine how the microstructure of food intake relates to the metabolic consequences of social subordination. Male Long-Evans rats were housed in mixed-sex VBS colonies (4 male, 2 female) for 2 weeks during which a dominance hierarchy formed (1 dominant male (DOM) and 3 subordinate males (SUB)), then male rats were individually-housed for a 3-week recovery period. Controls were individually housed with females during the 2-week VBS period and had no changes in ingestive behavior compared to a habituation period. During the hierarchy-formation phase of VBS-housing, DOM and SUB had a reduced meal frequency whereas SUB also had a reduced meal size. However during the hierarchy-maintenance phase of VBS-housing, DOM meal patterns did not differ from controls whereas SUB continued to display reduced food intake via less frequent meals. During recovery DOM had comparable meal patterns to controls, whereas SUB had an increased meal size. Hypothalamic neuropeptide Y (NPY) mRNA levels were not different between these groups during the experimental period. Together, the results suggest that exposure to chronic social stress alters ingestive behavior both acutely and in the long-term, which may influence the metabolic changes that accompany bouts of stress and recovery; however, these differences in meal patterns do not appear to be mediated by hypothalamic NPY.
- meal size
- body composition
- food intake
- Copyright © 2010, American Journal of Physiology - Regulatory, Integrative and Comparative Physiology