在体光遗传学—电生理相结合研究—侧半球控制双侧上肢运动的脑功能重塑机制
发布时间：2018-08-22 14:05
【摘要】：背景：作为中枢神经损伤后较为严重的后遗症之一,上肢痉挛性瘫痪的治疗方法及效果均有限。课题组前期研究发现：通过改变周围神经通路增强同侧神经纤维对肢体的支配可以实现偏瘫患者的健存大脑半球同时司管双侧上肢。但具体涉及到的神经通路以及患肢运动功能恢复的动态中枢机制尚不明确。本课题使用Thy1-ChR2-EYFP转基因小鼠建立脑外伤和健侧颈七神经根移位至患侧颈七神经根的模型,通过光遗传学-电生理相结合的技术、行为学以及逆行跨多突触的神经示踪技术,研究瘫痪肢体运动功能恢复的中枢机制。该技术具有皮层定位及刺激精确可控、可重复性佳以及高效无创的不可替代优势,研究成果将有助于揭示一侧皮层司管双侧上肢的动态重塑规律,为后续积极干预脑重塑,促进卒中、脑瘫、脑外伤后遗症的上肢功能恢复研究提供依据。方法：我们建立了小鼠左侧控制性皮层撞击脑外伤(CCI)及健侧颈七-患侧颈七神经根切断及移位模型,术后通过滚轴实验和阶梯步行实验检测上肢运动功能的损伤及恢复情况,在体光遗传学-电生理技术相结合用于绘制正常小鼠初级运动皮层M1、前肢各肌肉代表区图谱以及动态记录术后不同时间点健侧皮层刺激后双侧上肢各靶肌肉代表区位置及运动诱发电位(MEP)参数的变化。采用伪狂犬病毒PRV-Bartha株dsred自患肢颈七神经根注射,连续冰冻切片及免疫组化观察其在健侧皮层的神经元标记情况。结果：左侧CCI后,小鼠对侧肢体在滚轴实验和阶梯步行实验的评分均出现显著的降低,对照组(CCI+双侧颈七切断组以及单纯CCI组)的评分在CCI后1月内均出现了一定程度的上升,但之后直至术后10个月对照组的患肢行为学评分未进一步恢复,而实验组(CCI+健侧颈七-患侧颈七移位组)的患肢在术后5月时滚轴实验的姿态、头部姿势以及前屈项目行为学评分开始好于对照组,至术后6个月时更为显著且一直持续至术后10月。术后7月时患肢在滚轴实验的提携项目评分以及阶梯步行实验评分开始好于对照组,至术后8个月时更为显著且一直持续至术后10月。而健侧肢体功能仅在术后1月内评分下降,术后1月恢复至术前并维持至术后10月。我们通过光遗传学方法绘制了转基因小鼠M1图谱,并发现前肢代表区由位于偏前方较小面积的代表区RFA(6±1个刺激位点,主要诱发出腕及趾活动)以及偏后方较大面积的代表区CFA(44±4个刺激位点,主要诱发出肩肘及部分腕活动)构成。术后4月以内,右(健)侧皮层刺激仅能记录到左(健)侧肢体靶肌肉的MEP；术后5月时,右(健)侧皮层刺激可以同时记录到双侧肱三头肌的MEP,且术后右(患)侧肱三头肌代表区逐渐缩小并向左(健)侧肱三头肌代表区汇聚；术后7月时,右(健)侧皮层刺激可以同时记录到双侧前臂伸肌群的MEP,且术后右(患)侧前臂伸肌群代表区呈现出逐渐缩小并向左(健)侧前臂伸肌群代表区汇聚的趋势,而右(健)侧皮层内刺激始终无法诱发出右(患)侧肱二头肌的MEP。右(健)侧皮层刺激诱发出左(健)侧肢体靶肌肉的代表区及波幅未见明显变化。单纯CCI组小鼠及CCI+双侧颈七神经根切断的小鼠的右(健)侧皮层在各时间点均未发现被标记的神经元,而CCI+健侧颈七移位的小鼠在术后5月,健侧皮层中己能找到少量被标记的神经元,术后7月直至10月健侧皮层中被标记的神经元密度进一步增高。结论：对于重度CCI小鼠,健侧颈七神经根移位术可以促进患肢粗大(伸肘)及部分精细(伸腕指及协调)功能的恢复,前者恢复更为显著。术后健侧皮层参与了对双侧上肢运动的支配,患肢代表区在术后早期覆盖了健肢代表区,且前者呈现出向后者逐渐缩小汇聚、精确有序的趋势。
[Abstract]:BACKGROUND: As one of the more serious sequelae after central nerve injury, the therapeutic methods and effects of spastic paralysis of the upper extremity are limited. Previous studies have found that hemiplegic patients can survive cerebral hemisphere and manage bilateral upper extremities simultaneously by changing peripheral nerve pathways to enhance the innervation of ipsilateral nerve fibers to the extremities. The specific neural pathways involved and the dynamic central mechanism underlying the recovery of motor function in the affected limbs are still unclear. In this study, we used Thy1-ChR2-EYFP transgenic mice to establish models of brain injury and translocation of contralateral cervical seven nerve roots to the affected cervical seven nerve roots. Neural tracing technique is an irreplaceable technique with precise and controllable cortical location and stimulation, good repeatability and high efficiency. The results of this study will help to reveal the dynamic remodeling regularity of bilateral upper limbs of unilateral cortical canal, and actively intervene in brain remodeling and promote the follow-up. Methods: The models of CCI and CCI were established in mice with stroke, cerebral palsy and sequelae of traumatic brain injury. The combination of somatogenetics and electrophysiology was used to map the primary motor cortex M1, the representative areas of forelimb muscles, and to dynamically record the position of target muscles and the changes of motor evoked potential (MEP) parameters in bilateral upper limbs after stimulation of contralateral cortex at different time points. Results: After CCI, the scores of contralateral limbs in rolling test and stepped walking test were significantly lower than those in control group (CCI + bilateral cervical 7 amputation group and CCI group) within 1 month after CCI. However, the behavioral scores of the affected limbs in the control group did not recover further until 10 months after operation. The posture, head posture and bending item behavioral scores of the affected limbs in the experimental group (CCI + CCI + CCI + CCI + CCI) were better than those in the control group at 5 months after operation. 7 months after operation, the scores of lifting items and step walking test of the affected limbs were better than those of the control group, and were more significant at 8 months after operation and lasted until 10 months after operation. We mapped the M1 map of transgenic mice by photogenetics. We found that the forelimb representative region was composed of RFA (6 + 1 stimulus loci, mainly inducing wrist and toe activity) located in a small area in the front and CFA (44 + 4 stimulus loci, mainly inducing shoulder, elbow and part of wrist) in a large area in the rear. Within 4 months after surgery, the right (healthy) cortical stimulation could only record the MEP of the target muscle of the left (healthy) limb; 5 months after surgery, the right (healthy) cortical stimulation could simultaneously record the MEP of the bilateral triceps brachii, and the representative area of the right (affected) triceps brachii decreased gradually and converged to the left (healthy) triceps brachii. MEP of bilateral forearm extensors could be recorded simultaneously by right (healthy) cortical stimulation, and the representative area of right (affected) forearm extensors decreased gradually and converged to the representative area of left (healthy) forearm extensors, while the right (healthy) cortical stimulation could not induce MEP of right (affected) biceps brachii. No marked neurons were found in the right (healthy) cortex of CCI group mice and CCI + bilateral rhizotomy mice at all time points, while a small number of marked neurons were found in the contralateral cortex of CCI + transposition mice 5 months after operation. The density of the labeled neurons in the contralateral cortex was further increased from July to October. Conclusion: For severe CCI mice, transposition of the contralateral seven nerve roots can promote the recovery of the thick (elbow extension) and some fine (wrist extension and coordination) functions of the affected limbs, and the former is more significant. During the early postoperative period, the representative area of the affected limb covered the representative area of the healthy limb, and the former gradually reduced to the latter, accurately and orderly.
【学位授予单位】：复旦大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R741
本文编号：2197326
[Abstract]:BACKGROUND: As one of the more serious sequelae after central nerve injury, the therapeutic methods and effects of spastic paralysis of the upper extremity are limited. Previous studies have found that hemiplegic patients can survive cerebral hemisphere and manage bilateral upper extremities simultaneously by changing peripheral nerve pathways to enhance the innervation of ipsilateral nerve fibers to the extremities. The specific neural pathways involved and the dynamic central mechanism underlying the recovery of motor function in the affected limbs are still unclear. In this study, we used Thy1-ChR2-EYFP transgenic mice to establish models of brain injury and translocation of contralateral cervical seven nerve roots to the affected cervical seven nerve roots. Neural tracing technique is an irreplaceable technique with precise and controllable cortical location and stimulation, good repeatability and high efficiency. The results of this study will help to reveal the dynamic remodeling regularity of bilateral upper limbs of unilateral cortical canal, and actively intervene in brain remodeling and promote the follow-up. Methods: The models of CCI and CCI were established in mice with stroke, cerebral palsy and sequelae of traumatic brain injury. The combination of somatogenetics and electrophysiology was used to map the primary motor cortex M1, the representative areas of forelimb muscles, and to dynamically record the position of target muscles and the changes of motor evoked potential (MEP) parameters in bilateral upper limbs after stimulation of contralateral cortex at different time points. Results: After CCI, the scores of contralateral limbs in rolling test and stepped walking test were significantly lower than those in control group (CCI + bilateral cervical 7 amputation group and CCI group) within 1 month after CCI. However, the behavioral scores of the affected limbs in the control group did not recover further until 10 months after operation. The posture, head posture and bending item behavioral scores of the affected limbs in the experimental group (CCI + CCI + CCI + CCI + CCI) were better than those in the control group at 5 months after operation. 7 months after operation, the scores of lifting items and step walking test of the affected limbs were better than those of the control group, and were more significant at 8 months after operation and lasted until 10 months after operation. We mapped the M1 map of transgenic mice by photogenetics. We found that the forelimb representative region was composed of RFA (6 + 1 stimulus loci, mainly inducing wrist and toe activity) located in a small area in the front and CFA (44 + 4 stimulus loci, mainly inducing shoulder, elbow and part of wrist) in a large area in the rear. Within 4 months after surgery, the right (healthy) cortical stimulation could only record the MEP of the target muscle of the left (healthy) limb; 5 months after surgery, the right (healthy) cortical stimulation could simultaneously record the MEP of the bilateral triceps brachii, and the representative area of the right (affected) triceps brachii decreased gradually and converged to the left (healthy) triceps brachii. MEP of bilateral forearm extensors could be recorded simultaneously by right (healthy) cortical stimulation, and the representative area of right (affected) forearm extensors decreased gradually and converged to the representative area of left (healthy) forearm extensors, while the right (healthy) cortical stimulation could not induce MEP of right (affected) biceps brachii. No marked neurons were found in the right (healthy) cortex of CCI group mice and CCI + bilateral rhizotomy mice at all time points, while a small number of marked neurons were found in the contralateral cortex of CCI + transposition mice 5 months after operation. The density of the labeled neurons in the contralateral cortex was further increased from July to October. Conclusion: For severe CCI mice, transposition of the contralateral seven nerve roots can promote the recovery of the thick (elbow extension) and some fine (wrist extension and coordination) functions of the affected limbs, and the former is more significant. During the early postoperative period, the representative area of the affected limb covered the representative area of the healthy limb, and the former gradually reduced to the latter, accurately and orderly.
【学位授予单位】：复旦大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R741
【参考文献】
相关期刊论文 前4条
1 古菁;黄怀;虞容豪;李宁;;脑外伤的康复评定和治疗进展[J];重庆医学;2009年08期
2 巢乃健;李胜天;;光学技术在神经科学中的应用及其进展[J];生物物理学报;2012年11期
3 朱秀卿,闫克里;急性脑卒中的治疗研究现状[J];中国药物与临床;2005年11期
4 张小年;张皓;;创伤性颅脑损伤国内研究进展[J];中国康复理论与实践;2008年02期
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