Social hierarchy affects depression-like behavior and gene expression in mouse brain

Press Release

Hierarchy in the home cage affects behaviour and gene expression in group-housed C57BL/6 male mice

Yasuyuki Horii, Tatsuhiro Nagasawa, Hiroyuki Sakakibara, Aki Takahashi, Akira Tanave, Yuki Matsumoto, Hiromichi Nagayama, Kazuto Yoshimi, Michiko T. Yasuda, Kayoko Shimoi, Tsuyoshi Koide

Scientific Reports Article number: 6991 (2017) DOI:10.1038/s41598-017-07233-5

Pressrelease (In Japanese only)

Social stress is one of the major causes of depression in humans. It is therefore important that the effects of social stress on behaviour and gene expression in the brain are studied. We performed experiments using male mice to analyse social hierarchy in groups of mice in cages and investigated emotional behaviour and hippocampal gene expression in the mice. We found significantly different emotional behaviour and expression of genes associated with the serotonergic system in dominant and subordinate mice. Treating the mice with a selective serotonin reuptake inhibitor antidepressant restored gene expression in subordinate mice and caused the emotional behaviour of the subordinate mice to be recovered, suggesting that alterations to the serotonergic system are key factors in phenotypic changes caused by the social ranks of subordinate mice. We believe that the results of this study are important because they improve our understanding of how social stress induces mental health problems in humans.