1. Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐sen University, Ministry of EducationGuangzhou510080 China
2. Department of Histology and EmbryologyGuangdong Medical UniversityZhanjiang524023 China
3. Department of Histology and EmbryologyZhongshan School of Medicine, Sun Yat‐sen UniversityGuangzhou510080 China
4. Department of Electron MicroscopeZhongshan School of Medicine, Sun Yat‐sen UniversityGuangzhou510080 China
5. Department of AnatomyYong Loo Lin School of Medicine, National University of SingaporeSingapore117597 Singapore
6. Institute of Spinal Cord Injury, Sun Yat‐sen UniversityGuangzhou510120 China
7. Co‐innovation Center of Neuroregeneration Jiangsu226019 China
8. Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat‐sen UniversityGuangzhou510080 China