实验性不同类型大鼠臂丛根性损伤后脊髓运动神经元存活情况观察

目的 研究臂丛神经根性切断伤与根性撕脱伤后脊髓前角运动神经元的存活情况。方法 对76只健康成年SD大鼠,按手术先后顺序分成臂丛神经根性切断伤组和根性撕脱伤组,两组按术后9个不同的时间组取材,每组4只大鼠,共72只大鼠。另外4只为正常对照组。取了脊髓标本后,观察颈髓前角运动神经元数目的变化。结果 臂丛神经根性切断伤后,各时间组的脊髓前角运动神经元数目和术前无明显变化;而根性撕脱伤组于术后1周其神经元数目开始减少,术后2周时神经元数目比正常对照组减少30％,术后6周时减少70％。撕脱伤组与切断伤组相比,损伤1周后,各时间组的差异均有显著性意义（X^2＝3．922－17．21,P＜0．01）。结论 臂丛神经根性切断伤其脊髓运动神经元和术前比无明显变化,而臂丛神经性撕脱伤后其脊髓运动神经元有死亡,死亡速度快,死亡程度高。     

两种天然抗氧化剂对臂丛根性撕脱后脊髓运动神经元保护作用的比较

目的 比较植物抗氧化剂TA9001和EGb761对臂丛根性撕脱后C7前角运动神经元c-jun、nNOS表达和运动神经元存活的影响。方法 成年Sprague-Dawley雌性大鼠180只，随机分为TA9001组、EG761组和对照组。行右侧臂丛神经根性撕脱术后，三组大鼠每天分别给予腹腔注射1ml 0．5％TA9001、0．5％EGb761和生理盐水。治疗后4h、12h、1d、3d、5d、1周、2周、4周和6周取材，行c-jun免疫细胞化学、NADPH-d组织化学和中性红复染。结果 c-jun和nNOS仅在损伤运动神经元出现，c-jun表达开始于4h，1d达高峰，随后下降直至2周。nNOS表达从5d开始，2周达高峰，以后逐渐下降至6周。运动神经元的死亡开始于2周，以4周-6周最明显。TA9001和EGb761治疗后都能上调c-jun，下调nNOS表达，提高运动冲经元存活。EGb761上调c-jun表达的程度明显强于TA9901；两者减少NOS表达和提高运动神经元存活的效果一致。结论 TA9901和EGb761都有保护受损运动神经元的功效，nNOS表达与运动神经元死亡的关系更密切。     

大鼠臂丛放射性损伤后脊髓前角运动神经元病理变化及c-fos基因表达

目的模拟乳癌放疗方案，观察实验大鼠臂丛神经受照射后相应脊髓前角运动神经元的病理改变及c—fos基因表达。方法采用剂量分割照射方案，建立大鼠臂丛神经放射性损伤动物模型。将加只SD大鼠随机分成臂丛神经损伤组（实验组）和正常对照组，实验组又根据损伤后取材时间的不同分成损伤后3、5、7和9周4个时间组，每个时间组和对照组各4只大鼠，每个时间组以左侧为照射侧，右侧为对照侧，采用日照射2Gy／次，每周5次深部X线照射，累计剂量达到30Gy后，分别于末次照射后3、5、7和9周取材。检测两侧脊髓前角运动神经元形态及数目变化并以免疫组织化学染色法检测c—fos在前角运动神经元中的表达。结果大鼠臂丛神经受照射后3周，实验组照射侧脊髓前角运动神经元存活数目随时间延长而明显减少，神经元内有明显的c—fos染色，c—fos阳性细胞数渐减。照射后9周，c-fos阳性细胞偶见。结论大鼠臂丛神经受大剂量X线照射后可使大鼠脊髓前角运动神经元存活数目明显减少；与脊髓神经元凋亡相关的c—fos基因呈阳性表达，表明原癌基因的表达在臂丛神经放射损伤的凋亡、损伤和修复过程中起重要作用。     

臂丛损伤神经干细胞脊髓前角移植后分化情况及对运动神经元的保护作用

目的观察臂丛根性撕脱伤后将脊髓源性神经干细胞(neuralstemcell,NSC)移植于脊髓前角后的存活、分化情况及对脊髓前角受损运动神经元的保护作用。方法取新生鼠脊髓,分离获得脊髓源性神经干细胞,体外培养、扩增、鉴定、5溴2-脱氧尿苷(BrdU)标记。取SD大鼠60只,随机分成实验组、对照组和单纯组。从后路制备C5~C7臂丛神经根性撕脱伤动物模型。实验组移植神经干细胞于C6脊髓前角,对照组移植灭活神经干细胞,单纯组不作移植。术后1、2、4、8、12周取脊髓标本进行组织学与免疫组化染色观察。结果神经干细胞移植入脊髓后能存活、分化;臂丛根性撕脱伤后脊髓前角运动神经元数目明显减少;实验组神经干细胞移植后2、4、8、12周各个时间点运动神经元的存活率均高于对照组和单纯组。结论臂丛根性撕脱伤脊髓前角神经干细胞移植后能存活并分化为神经元及星型胶质细胞,脊髓源性神经干细胞移植能明显减少前角运动神经元的继发性死亡,对脊髓前角受损运动神经元有保护作用。     

臂丛根性损伤脊髓前角α运动神经无数目变化的实验研究

以Sprague-Dawly大鼠为研究对象，设计臂丛根性撕脱伤的实验模型，研究臂丛根性撕脱后脊髓前角α运动神经元数目变化。实验结果表明：臂丛根性撕脱伤后脊髓前角α运动神经元死亡23．7％。     

细胞外ATP对臂丛神经根性撕脱伤后脊髓运动神经元保护的实验研究

目的 观察细胞外ATP对臂丛神经根性撕脱伤所致脊髓前角运动神经元损伤的保护作用. 方法 Wistar大鼠36只,随机分为两组:单纯神经根撕脱组和神经根撕脱加ATP治疗组.行左侧臂丛神经根性撕脱术,术后实验组腹腔注射ATP(2 mg/kg)0.4 nd,对照组腹腔注射生理盐水0.4 ml,均为1次/日,连续应用ATP或生理盐水2周.术后2周、4周和6周后取材,处死动物后取C5～C8脊髓分别行一氧化氮合酶(NOS)、神经丝蛋白(NF-200)免疫组织化学染色. 结果 术后2、4和6周,实验组脊髓前角运动神经元存活率为80.48%、73.55%、53.43%,对照组为68.90%、63.58%、37.72%,实验组与对照组比较脊髓前角运动神经元死亡率分别降低了11.58%、9.87%和15.71%(P<0.01);实验组脊髓前角运动神经元中NOS阳性率为17.85%、40.20%、18.03%,对照组为25.53%、53.88%、25.58%,实验组与对照组比较.脊髓前角运动神经元中NOS阳性率分别下降了7.68%(P<0.01)、13.68%和7.55%(P<0.05);实验组脊髓前角运动神经元的NF-200阳性细胞数均高于对照组,两者比较差异有统计学意义. 结论 ATP对臂丛神经根性撕脱伤后脊髓前角运动神经元具有保护作用.     

神经干细胞对脊髓前角运动神经元保护作用的实验研究

目的观察臂丛根性撕脱伤后神经干细胞脊髓内移植对前角运动神经元的保护作用。方法取孕龄15～18d胎鼠脑组织，分离获得神经干细胞，在体外培养、扩增，并用5溴-2脱氧尿苷(BrdU)标记。取Wistar大鼠72只，随机分成实验组与对照组。先将C5～T1神经根撕脱，实验组把体外培养的神经干细胞移植于C5～T1脊髓节段前角附近，而对照组则用缓冲液替代神经干细胞。术后1、2、4、6、8、12周取脊髓标本进行组织学与免疫组化染色观察。结果臂丛根性撕脱伤后脊髓前角运动神经元数目明显减少，到术后12周时，对照组运动神经元减少达80．3％，实验组达63．7％。并且，各时间点实验组运动神经元的存活率均高于对照组。实验组脊髓前角内可见散在但仍保持未分化特征的神经干细胞。结论神经干细胞在植入臂丛根性撕脱伤的脊髓后能存活，并能明显减少前角运动神经元的继发性死亡。     

神经根修复时间对脊髓前角运动神经元存活的影响

目的评价神经根修复时间对脊髓前角运动神经元存活的影响。方法采用大鼠颈。神经根性撕脱伤和椎孔外切断实验动物模型，根据动物神经根损伤类型和损伤后修复时间分为A、B、C、D四组，每组16只。A、C组分别将撕脱与切断的神经根即刻回植入脊髓和于椎孔外直接吻合，B、D组将撕脱和椎孔外切断的神经根旷置3周后再重复上述手术。分别于神经根撕脱和椎孔外切断术后3周、3个月、6个月取材。应用组织病理活检、免疫组化技术及神经示踪技术，对神经中枢及吻合口下段神经干检查，观察脊髓病理改变和轴突再生情况，进行A、B组和C、D组间对比。结果臂丛神经根性损伤即刻修复组脊髓前角运动神经元和尼氏体数目、形态、减少程度及周围再生神经纤维数目、发育程度均优于损伤后3周修复组。结论神经根早期修复对脊髓前角运动神经元有明确的保护作用，对外周神经再生有促进作用。     

抗氧化剂对脊神经根撕脱伤后脊髓运动神经元的影响

目的 观察抗氧化剂对脊神经根撕脱后脊髓前角运动神经元NOS、c-jun表达和神经元死亡的保护作用。方法 成年Sprague-Dawley雌性大鼠20骨只，随机分为；单纯神经根撕脱组和神经根撕脱加抗氧化剂治疗组。在手术显微镜下进行脊髓C6-C8节段神经根撕脱术，术后治疗组每天给予腹腔注射0.5%抗氧化剂（TA9902）水溶液1ml，对照组仅腹腔注射等量生理盐水，术后2组均饲养3周和6周后处死动物并分别行c-jun免疫组织化学染色和NADPH-d黄递酶染色。结果 术后3周和6周抗氧化剂给药组的NOS阳性率均明显低于对照组；给药组的神经细胞存活率分别为76.25%和39.16%，术后3周与对照组比较，差异有显著性，而术后6周，其神经细胞存活率与对照组比较差异无显著性。给药组脊髓前角运动神经元的c-jun阳性细胞数均高于对照组，两者之间的差异有显著性。结论 抗氧化剂具有抑制神经元NOS表达的作用。并对损伤的神经元具有保护效应。但该药物的神经元保护作用主要在损伤后早期有效。     

臂丛神经根性撕脱伤后神经营养因子在脊髓及肌肉中表达的变化

目的：通过观测臂丛神经根性撕脱伤后脊髓前角运动神经元及肌肉组织内神经营养因子表达的变化。探讨臂丛神经撕脱伤后中枢运动神经元,靶器官的功能改变可能对神经再生产生的影响。方法：清洁级Wistar大鼠48只,随机分成正常对照组和损伤术后1天,1,4,8和12周共六组,损伤组均从前路造成臂丛颈5,6,7神经根性撕脱伤,按各组所示时间取脊髓及肌肉分别检测碱性成纤维细胞生长因子（bFGF)蛋白及mRNA,神经生长因子（NGF）蛋白的表达,并采用计算机图像分析系统对组织切片中bFGF蛋白及mRNA,NGF蛋白进行半定量分析,比较,结果：臂丛神经根性撕脱伤后,肱二头肌内NGF蛋白表达增高,1天时达到高峰,随后下降,3个月时仍高于对照组,而脊髓前角运动神经元bFGF蛋白及mRNA的表达在伤后亦升高,1周时达到高峰,随后下降,3个月时下降到稍低于正常水平,结论：臂丛神经根性撕脱伤后神经营养因子在中枢神经元及靶器官内表达增高,可能起保护神经元,促进神经再生的作用。     

Valproic acid protection against the brachial plexus root avulsion‐induced death of motoneurons in rats

In this study, the role of valproic acid (VPA) in protecting motoneuron after brachial plexus root avulsion was investigated in adult rats. Sixty rats were used in this study, and underwent the brachial plexus root avulsion injury, which was created by using a micro‐hemostat forceps to pull out brachial plexus root from the intervertebral foramen. The animals were divided into two groups, VPA group administered with VPA dissolved in drinking water (300 mg/kg) daily, and control group had drinking water every day. The spinal cords (C5‐T1) were harvested at day 1, 2, 3, 7, 14, and 28 for immunohistochemistry analysis, TUNEL staining, Nissl staining, and electron microscopy, respectively. The results showed that with VPA administration, the survival of motoneurons was promoted and the cell apoptosis was inhibited. The number of c‐Jun and Bcl‐2 positive motoneurons was increased immediately after avulsion both in control and VPA group, however, the percent of c‐Jun positive motoneurons was decreased and the percent of Bcl‐2 positive motoneurons was increased by VPA treatment significantly. Our results indicated that motoneurons were protected by VPA against cell death induced by brachial plexus root avulsion through c‐Jun inhibition and Bcl‐2 induction. © 2013 Wiley Periodicals, Inc. Microsurgery 33:551–559, 2013.     

成年大鼠全臂丛根性撕脱伤后初级体感皮层可塑性变化的脑电生理研究

目的 探讨成年大鼠一侧全臂丛根性撕脱伤后双侧初级体感皮层可塑性变化的规律。方法 将30只SD雄性大鼠分为6组，分为正常对照组和全臂丛根性撕脱伤术后1d、7d、1个月、3个月、1年共5个时间组，每组5只。采用体感皮层诱发电位（somatosensory evoked potential，SEP）记录法，定量评价一侧全臂丛根性撕脱伤后双侧初级体感皮层（Sm1）可塑性变化的时程。结果 术后不同时间段电刺激患爪正中神经支配区，在双侧Sm1均未诱发出SEP。电刺激健侧前爪正中神经支配区，在健爪同侧Sm1未记录到SEP，只在其对侧Sm1记录到SEP；但不同时间段的SEP位点数目均明显多于正常对照组。结论 成年大鼠的初级体感皮层仍具有可塑性，一侧全臂丛根性撕脱伤后诱发了双侧Sm1动态的功能重组。两大脑半球相对应的同位区域之间存在着维持半球间平衡和协调的特殊机制。健侧前爪体感代表区的扩大可提高健爪的感觉辨别能力，以部分代偿患肢感觉功能的丧失。     

Survival of injured spinal motoneurons in adult rat upon treatment with glial cell line-derived neurotrophic factor at 2 weeks but not at 4 weeks after root avulsion

We conducted a study of whether treatment with glial cell line-derived neurotrophic factor (GDNF) initiated at 2 or 4 weeks after spinal-root avulsion could promote survival and regulate neuronal nitric oxide synthase (nNOS) expression in adult rat spinal motoneurons. By 6 weeks after root avulsion, the treatment given at 2 weeks not only increased motoneuron survival (86.1% vs. 27.9%), but also reversed the atrophy of injured motoneurons and increased their somatic size (101.3% vs. 52.9%) in comparison to the untreated control group of animals. All surviving motoneurons in the GDNF-treated group showed immunoreactivity for choline acetyltransferase. In contrast, GDNF treatment at 4 weeks post-injury failed to promote motoneuron survival (33.1% vs. 27.9%) at 6 weeks compared to the control group. Both the 2- and 4-week post-injury treatments downregulated nNOS expression. This finding suggests that injured adult motoneurons die shortly (a few weeks in the rat) after root avulsion injury, but can be saved from degeneration by treatment within the proper time frame after injury, which in the case of GDNF treatment in rats, appears to be within 2 weeks of the avulsion injury of the spinal root. These findings provide useful information for choosing the best time frame for the potential clinical treatment of brachial plexus avulsion.     

成年大鼠全臂丛根性撕脱伤后对侧运动皮层可塑性变化的实验研究

目的 探讨成年大鼠全臂丛根性撕脱伤后不同时间段对侧运动皮层的可塑性变化。方法 将30只SD雄性大鼠分为6组，即正常对照组和全臂丛根性撕脱伤术后1d、7d、1个月、3个月、1年共5个时间组，每组5只。采用皮层内微电极电刺激技术，定量评价大鼠左前肢代表区内的可塑性变化。结果 术后不同时间组在原前肢代表区内可诱发出不同的运动类型，包括左侧胡须、下颌、颈部和左下肢4个部位点的运动，但只有颈部位点自始至终占据着术前前肢代表区。结论 成年大鼠的运动皮层仍具有可塑性，术后对侧运动皮层在术前前肢代表区发生了功能重组，并且这种功能重组是动态变化的。瘫痪肢体以上最临近部位的肌肉控制力其代偿性明显增强。     

A new model for the study of neuropathic pain after brachial plexus injury

The study was to introduce a new and reliable behavioral model of upper trunk of brachial plexus avulsion for the study of persistent neuropathic pain. 60 rats were divided into three groups randomly: upper trunk of brachial plexus avulsion (UTBPA) group (20), global brachial plexus avulsion (GBPA) group (20), and sham- operated group (20). The animals were tested for behavioral responsiveness before surgeries and 3, 7, 14, 21, 28, 56, 84 days after surgeries. The injured level of spinal cord was resected and the sections were processed for GFAP (astrocyte) and Iba1 (microglia) immunohistochemistry 3 weeks after surgeries. The UTBPA group developed significant signs both of mechanical and cold hypersensitivity, which matched the immunohistochemistry result, as well as the nature of avulsion was close to the clinical type of injury, the UTBPA group could be used as a suitable and effective persistent neuropathic pain model following brachial plexus injury.     

椎管内外神经根移位整体化治疗臂丛神经根性撕脱伤的实验研究

目的：研究臂丛神经根性撕脱伤后,椎管内、外神经根移位治疗臂丛神经根性撕脱伤的疗效。方法随机选取SD大鼠60只,随机分为实验组及对照组。实验组采用椎管内C5,C6神经根原位修复及健侧C7神经移位修复C8,T1神经根治疗臂丛根性撕脱伤;对照组为膈神经修复肌皮神经,副神经修复肩胛上神经,健侧C7移位修复C8,T1神经根治疗臂丛根性撕脱伤。术后6个月时取材,进行电生理检测,肌肉湿重的测量,肌肉纤维横截面积的检测,HE染色检测观察肌纤维数量,电镜观察神经纤维数量及神经直径。结果实验组神经损伤修复6个月时,其肌肉湿重、肌肉纤维横截面积、肌肉运动诱发电位恢复率、神经生长情况优于对照组。结论椎管内神经根原位修复及椎管外神经根移位整体化治疗臂丛神经根性撕脱伤,无论从肌肉湿重、还是肌肉纤维横截面积比率,或者肌肉运动诱发电位及再生神经生长情况等方面,都取得了良好的效果。     

Effect of ipsilateral C7 nerve root transfer on restoration of rat upper trunk muscle and nerve function after brachial plexus root avulsion

The effects of ipsilateral cervical nerve root transfer on the restoration of the rat upper trunk muscle and nerve brachial plexus root avulsion were studied. After simulated root avulsion of the upper trunk brachial plexus, 120 rats were randomly divided into 4 groups: (A) ipsilateral C7 root transfer group; (B) Oberlin group; (C) phrenic nerve group; and (D) no axillary nerve restoration group. At 3, 6, and 12 weeks postoperatively, Ochiai score, Barth feet overreaching test, Terzis grooming test, and indices of neurotization were determined in 10 rats from each group. Twelve weeks postoperatively, nearly all the behavioral, neuroelectrophysiological, and histological outcomes of the axillary nerve and deltoid muscle and some of the indices of musculocutaneous nerve and biceps brachii function in the ipsilateral C7 group were superior to those in the other 3 groups. No significant difference was found between the ipsilateral C7 group and the other 3 groups in recovery rate of wet biceps muscle weight. No significant difference was found between the ipsilateral C7 group and the Oberlin group in the recovery of the axillary nerve compound muscle action potential and biceps brachii cell size. No significant difference was found between the ipsilateral C7 group and the phrenic nerve and no axillary nerve restoration groups in amplitude recovery rate of musculocutaneous nerve compound muscle action potential. No significant difference was found between the ipsilateral C7 and the Oberlin groups in the early recovery of musculocutaneous nerve compound muscle action potential, but recovery was significantly better in the ipsilateral C7 group at 12 weeks. Ipsilateral C7 root transfer can improve the quality of restoration of muscle and nerve function in the rat upper trunk after brachial plexus root avulsion.