title: Social competition in rats: cell proliferation and behavior.
abstract: Behavioral and physiological changes were studied following prolonged exposure to social competition in pairs of non-food-deprived rats competing daily for a limited supply of graham cracker crumbs. Stable dominant-subordinate relationships developed in most pairs, as measured by feeding time, which were maintained over a 5-6-week study period. In other behavioral tests, subordinates demonstrated a decreased latency to immobility in the forced swim test compared with dominants, but no difference in locomotor activity. Subordinates had increased bladder size, decreased adrenal gland size, and a 35% reduction of hippocampus cell proliferation compared with the dominant member. Therefore, prolonged social competition, based on restricted access to palatable substances, produced hierarchies among individuals that were associated with differences in behavior, physiology and hippocampal cell proliferation.
authors.affiliation: Department of Psychiatry, University of Pennsylvania, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Hoshaw
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Evans
authors.forename: Bridget
authors.initials: B
authors.lastname: Mueller
authors.forename: Rita J
authors.initials: RJ
authors.lastname: Valentino
authors.forename: Irwin
authors.initials: I
authors.lastname: Lucki
mesh_terms: D000311:Adrenal Glands / Q000033:anatomy & histology; D000818:Animals; D049109:Cell Proliferation; D003163:Competitive Behavior / Q000502:physiology*; D003345:Corticosterone / Q000097:blood; D018891:Dentate Gyrus / Q000166:cytology* / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology; D006608:Hierarchy, Social; D046353:Immobility Response, Tonic / Q000502:physiology; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009929:Organ Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000502:physiology; D012919:Social Behavior; D013315:Stress, Psychological / Q000503:physiopathology*; D013550:Swimming / Q000502:physiology / Q000523:psychology; D001743:Urinary Bladder / Q000033:anatomy & histology
chemical_list: D003345:Corticosterone