title: Resiliency to social defeat stress relates to the inter-strain social interaction and is influenced by season variation.
abstract: Exposure to social defeat (SD) stress exerts social avoidance and depressive disorders. Little is known about the relationship between resiliency to stressors and the inter-strain social interaction (SI) level. We hypothesized that SD resiliency is correlated with a high SI between the same strain. C57BL/6J mice experienced a 10-day period of SD stress by repeated CD-1 mice offensive. The susceptible mice exhibited significant social-avoidance behaviors with less time in interaction-zone (IZ) and lower social interaction ratio (SIR) toward the Target (CD-1 mice), while resilient ones exhibited similar social interaction to control mice. When the Target was C57BL/6J mouse, either susceptible or resilient mice spent more time in IZ and the inter-strain SI in the resilient group was significantly higher than the susceptible. Correlation analysis revealed a significantly non-zero slope of the linear relationship between SIRs toward two strains. But different groups had a similar baseline of the inter-strain SI before stress, indicating a SD-induced defect in both types of SI. In addition, in four different seasons, animals exhibited a significant resiliency to the stress in summer. These data suggest that SD resiliency is related to a higher SI toward the same-strain, and may be regulated by seasonal variations.
authors.affiliation: Department of Integrative Medicine and Neurobiology, Institutes of Brain Science and Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
authors.forename: Qiuqin
authors.initials: Q
authors.lastname: Han
authors.affiliation: Institute of Neurobiology, Fudan University, Shanghai 200032, PR China; Department of Integrative Medicine and Neurobiology, Institutes of Brain Science and Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China. Electronic address: ribaike@163.com.
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.affiliation: Institute of Neurobiology, Fudan University, Shanghai 200032, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Neurobiology, Fudan University, Shanghai 200032, PR China.
authors.forename: Ning
authors.initials: N
authors.lastname: Lv
authors.affiliation: Department of Integrative Medicine and Neurobiology, Institutes of Brain Science and Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China. Electronic address: yujin@shmu.edu.cn.
authors.forename: Jin
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Integrative Medicine and Neurobiology, Institutes of Brain Science and Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, PR China.
authors.forename: Gencheng
authors.initials: G
authors.lastname: Wu
authors.affiliation: Institute of Neurobiology, Fudan University, Shanghai 200032, PR China.
authors.forename: Yuqiu
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D003866:Depressive Disorder / Q000209:etiology / Q000523:psychology; D008297:Male; D008810:Mice, Inbred C57BL; D055500:Resilience, Psychological; D012621:Seasons; D012919:Social Behavior; D013315:Stress, Psychological / Q000150:complications / Q000523:psychology*
keywords: Depression; Seasonal regulation; Social defeat; Social interaction; Stressor