振荡电场对脊髓损伤大鼠运动功能恢复和轴突再生的影响

目的:探讨振荡电场对脊髓损伤大鼠运动功能恢复和轴突再生的影响。方法:改良Allen′s打击法建立90只SD大鼠脊髓损伤模型,随机分为实验组和对照组,两组均置入刺激电极。实验组施加振荡电场干预,对照组只置入振荡电场刺激器而不给予干预。电场强度600μV/mm,振荡周期为每15min极性交替变换,供电方式为感应式供电,工作方式为大鼠清醒状态下持续刺激至实验结束。建模成功后2周、6周、12周进行BBB评分、运动诱发电位评价脊髓神经传导情况(MEP潜伏期差和波幅差);HE染色行组织学观察,神经丝蛋白(NF200)、胶质纤维酸性蛋白(GFAP)免疫组化染色,观察轴突再生情况、行轴突计数、胶质瘢痕形成和星形胶质细胞突起夹角测量,两组间比较行t检验。结果:实验组和对照组比较,2周时,BBB评分、MEP波幅差和轴突计数无差异(P>0.05),但右下肢MEP潜伏期差缩短(P<0.05)。6周和12周时,BBB评分、MEP潜伏期差和波幅差、轴突计数和星形胶质细胞突起夹角测定两组间均有显著差异(P<0.05)。12周时HE染色观察两组可见损伤部位脊髓空洞及瘢痕形成;NF染色实验组可见较多神经纤维通过损伤区;GFAP染色发现两组间IOD值测定无显著差异。结论:振荡电场可以促进脊髓损伤大鼠的脊髓传导功能改善和后肢运动功能恢复,电场作用时间需达6周以上。大鼠后肢运动功能恢复可能与振荡电场促进轴突再生、诱导其定向生长,促进星形胶质细胞线性排列等有关。

Effect of oscillating electrical field on motor function recovery and axon regeneration in rat with spinal cord injury

Objectives:To explore the influence of oscillation field on motor function recovery and axon regeneration in rat with spinal cord injury.Methods:Ninety SD rats with spinal cord injury induced by Allen method was randomly divided into experimental group and control group.The stimulating electrode were added in both groups.The experimental group received oscillation electric field as intervention,while the control group experienced the implanted stimulator alone rather than the oscillation electric field.The electric field intensity was 600μV/mm.Every 15 min,the polarity alternated.The power supply mode was inductive system,and the rats received the stimulation in conscious state.At 2w,6w,12w after the experiment,BBB scores,motor evoked potentials(the MEP latency and amplitude difference),HE dyeing histology,neurofilament protein(NF200),glial fibers acid protein(GFAP) immunohistochemical,immunofluorescence stain were used to observe the axonal regeneration,axon counting,glial scar formation and astrocytes neurite angle measurement.The statistical analysis was performed between 2 groups.Results:Compared with control group of 2w,BBB scores,MEP amplitude difference and axon count in experimental group showed no significant difference,while the MEP latency period of right hindlimb showed significant difference(P<0.05).At 6w,12w,BBB scores,MEP latency period difference and amplitude difference,axon count and astrocytes neurite angle measurement all showed significant difference(P<0.05) compared with control group.At 12 week,the HE dyeing histological result showed no difference between 2 groups,which both presented with syringomyelia and glial scar formation.As for NF200 immunohistochemical stain,more nerve fibers were noted in experimental group than control group;as for GFAP immunohistochemical stain,the density and IOD values showed no difference between two groups.Conclusions:Oscillating electrical field can promote motor function recovery in rats with spinal cord injury,the inner mechanism may be related with promoting axon regeneration,inducing the directional growth,promoting astrocytes linear array and providing axon outgrowth channels.