Myelin Deficits Caused by Olig2 Deficiency Lead to Cognitive Dysfunction and Increase Vulnerability to Social Withdrawal in Adult Mice
Xianjun Chen 1,2 • Fei Wang 1 • Jingli Gan 2 • Zhonghua Zhang 2 • Xuejun Liang 2 • Tao Li 1 • Nanxin Huang 1 • Xiaofeng Zhao 3 • Feng Mei 1 • Lan Xiao 1
1 Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Army Medical University (Third Military Medical University), Chongqing 400038, China
2 Department of Psychiatry, Mental Diseases Prevention and Treatment Institute of The People’s Liberation Army (PLA), 988 Hospital of Joint Logistic Support Force of PLA, Jiaozuo 454003, China
3 Institute of Life Sciences, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
Oligodendrocyte (OL) and myelin development are crucial for network integration and are associated with higher brain functions. Accumulating evidence has demonstrated structural and functional impairment of OLs and myelin in serious mental illnesses. However, whether these deficits contribute to the brain dysfunction or pathogenesis of such diseases still lacks direct evidence. In this study, we conditionally deleted Olig2 in oligodendroglial lineage cells (Olig2 cKO) and screened the behavioral changes in adult mice. We found that Olig2 ablation impaired myelin development, which further resulted in severe hypomyelination in the anterior cingulate cortex. Strikingly, Olig2 cKO mice exhibited an anxious phenotype, aberrant responses to stress, and cognitive deficits. Moreover, Olig2 cKO mice showed increased vulnerability to social avoidance under the mild stress of social isolation. Together, these results indicate that developmental deficits in OL and myelin lead to cognitive impairment and increase the risk of phenotypes reminiscent of mental illnesses.
Oligodendrocyte; Olig2; Hypomyelination; Cognition; Social withdrawal