Tensile mechanical analysis of anisotropy and velocity dependence of the spinal cord white matter:a biomechanical study

作     者：Norihiro Nishida Itsuo Sakuramoto Yoshihiro Fujii Rudolf Yoga Hutama Fei Jiang Junji Ohgi Yasuaki Imajo Hidenori Suzuki Masahiro Funaba Xian Chen Takashi Sakai Norihiro Nishida;Itsuo Sakuramoto;Yoshihiro Fujii;Rudolf Yoga Hutama;Fei Jiang;Junji Ohgi;Yasuaki Imajo;Hidenori Suzuki;Masahiro Funaba;Xian Chen;Takashi Sakai

作者机构：Department of Orthopedic SurgeryYamaguchi University Graduate School of MedicineMinami-KogushiUbeYamaguchiJapan Department of Mechanical and Electrical EngineeringNational Institute of Technology Tokuyama CollegeGakuendaiShunanYamaguchiJapan Faculty of EngineeringYamaguchi UniversityTokiwadai UbeYamaguchiJapan 

出 版 物：《Neural Regeneration Research》 (中国神经再生研究（英文版）)

年 卷 期：2021年第16卷第12期

页      面：2557-2562页

核心收录：

学科分类：0710[理学-生物学] 100208[医学-临床检验诊断学] 1002[医学-临床医学] 1001[医学-基础医学(可授医学、理学学位)] 100104[医学-病理学与病理生理学] 10[医学] 

基　　金：This work was supported by the Japan Society for the Promotion of Science(KARENHI grant number JP 15K20002) by the Yamaguchi University Hospital(a translational promotion grant). 

主　　题：anisotropy dependence external force mechanistic analysis spinal cord injury straining rate stress velocity dependence white matter 

摘      要：In spinal cord injuries,external forces from various directions occur at various velocities.Therefore,it is important to physically evaluate whether the spinal cord is susceptible to damage and an increase in internal stress for external forces.We hypothesized that the spinal cord has mechanical features that vary under stress depending on the direction and velocity of injury.However,it is difficult to perform experiment because the spinal cord is very soft.There are no reports on the effects of multiple external forces.In this study,we used bovine spinal cord white matter to test and analyze the anisotropy and velocity dependence of the spinal cord.Tensile-vertical,tensile-parallel,shear-vertical,and shear-parallel tests were performed on the white matter in the fibrous direction(cranial to caudal).Strain rate in the experiment was 0.1,1,10,and 100/s.We calculated the Young’s modulus of the spinal cord.Results of the tensile and shear tests revealed that stress tended to increase when external forces were applied parallel to the direction of axon fibers,such as in tensile-vertical and shear-vertical tests.However,external forces those tear against the fibrous direction and vertically,such as in tensile-parallel and shear-parallel tests,were less likely to increase stress even with increased velocity.We found that the spinal cord was prone to external forces,especially in the direction of the fibers,and to be under increased stress levels when the velocity of external forces increased.From these results,we confirmed that the spinal cord has velocity dependence and anisotropy.The Institutional Animal Care and Use Committee of Yamaguchi University waived the requirement for ethical approval.