Chronic social defeat stress caused region-specific oligodendrogenesis impairment in adolescent mice.

INTRODUCTION

Social stress in adolescents precipitates stress-related emotional disorders. In this study we aimed to investigate oligodendrogenesis in three stress-associated brain regions, medial prefrontal cortex (mPFC), habenula, and amygdala in adolescent mice exposed to social defeat stress.

METHODS

Four-week-old adolescent mice were subjected to social defeat for 10 days, followed by behavioral tests and evaluations of oligodendroglial proliferation and differentiation.

RESULTS

Stressed mice showed reduced social interaction, more stretched approach posture, lower sucrose preference, but no changes in the forced swimming test. EdU labeled proliferative cells, newly formed NG2EdU + oligodendrocyte precursor cells (OPCs), and Olig2EdU oligodendrocyte lineage cells (OLLs) were significantly decreased in the mPFC and the lateral habenula, but not in the amygdala and the medial habenula in socially defeated mice. APCEdu newly-generated mature oligodendrocytes (OLs) were decreased in the mPFC in stressed mice. However, the total number of NG2 OPCs, APC mature OLs, and Olig2 OLLs were comparable in all the brain regions examined between stressed and control mice except for a decrease of APC mature OLs in the prelimbic cortex of stressed mice.

CONCLUSION

Our findings indicate that adolescent social stress causes emotion-related behavioral changes and region-specific impairment of oligodendrogenesis.