从新生小鼠、大鼠及鸡胚背根神经节分离的细胞培养

为了研究神经生长因子(NGF)对背根神经背细胞培养的作用,我们建立了背根神经节分离细胞培养的方法。在培养过程中观察了新生小鼠、大鼠以及鸡胚背根神经节细胞的生长分化。结果表明:在节根节神经元体外培养的早期1～2天NGF为必需的营养因子,而培养后期则不为背根神经节细胞生长所必需,在无NGF的条件下背根神经节细胞能继续存活。     

一种大鼠脊髓背根神经节细胞培养模型的建立

神经细胞形态万千、功能各异，而要研究其在整体中的功能，单靠简单的胚胎及新生动物的原代神经元或传代的杂交神经胶质瘤细胞是行不通的。脊髓背根神经节(dorsal root ganglion，DRG)是躯体和内脏感觉信号中枢途径的第一站，其初级感觉神经元是伤害性感觉信息从外周到中枢的重要传导站，该部位的受体、递质及离子通道现已成为痛觉研究     

胶原酶对大鼠脊神经背根神经节神经电位传导的影响

目的通过神经电位传导速度测定,研究胶原酶对大鼠脊神经背根神经节功能的影响。方法57只健康的Sprague-Dawley雄性大鼠随机分为正常组、胶原酶急性实验模型组、亚急性实验模型组和慢性实验模型组;急性假手术组、亚急性假手术组和慢性假手术组。分离、暴露实验大鼠左侧腰5背根神经节,并在各胶原酶实验模型组局部滴注胶原酶1ml(1200u/4ml),各假手术组局部滴注生理盐水1ml。分别于注药后1h、1周、30d行包含背根神经节的一段神经的神经电位传导速度检测。统计分析采用统计软件SPSS11.0。结果各组神经电位传导速度相比较差异均无显著性。结论临床应用的胶原酶化学髓核溶解术的胶原酶治疗浓度不影响大鼠脊神经背根神经节和传导神经的神经电生理功能。     

体外培养的贲门癌组织对神经节突起的促生长和诱向作用

目的：探讨体外培养条件下肿瘤组织和原代培养肿瘤细胞对鸡胚神经节神经元的影响。方法：（１）贲门癌组织块和原代培养的肿瘤细胞与鸡胚背根神经节共培养;（２）贲门癌组织／原代细胞培养液与鸡胚背根神经节和交感神经节共培养;（３）贲门癌组织／原细胞培养液中加入神经生长因子（ｎｅｒｖｅ ｇｒｏｗｔｈ ｆａｃｏｔｒ,ＮＧＦ）抗体后与鸡前根神经节和交感神经节共培养。结果：（１）贲门癌组织块及原代培养的肿瘤细胞对神经     

背根神经节端侧吻合延缓失神经骨骼肌萎缩的实验研究

 目的 建立背根神经节端侧吻合营养失神经腓肠肌的动物模型,观察其延缓失神经骨骼肌萎缩的作用.方法 选用48只SD大鼠,随机分成两组,实验组:腓肠肌失神经支配加背根神经节端侧吻合;对照组:腓肠肌单纯完全失神经支配.于术后4、8、12周各时间段,分别测定腓肠肌纤颤电位波幅、肌湿重、肌细胞直径及截面积,并观察背根神经节中感觉神经元的变化,判断肌萎缩的程度.结果 术后1～3个月背根神经节中均见到存活的感觉神经元,纤颤电位波幅实验组大于对照组;术后4、8、12周,实验组的肌湿重,肌细胞直径及截面积明显高于对照组.结论 周围神经损伤后的3个月内,背根神经节端侧吻合后感觉神经元能有效的延缓失神经骨骼肌萎缩.     

新生大鼠皮层神经元的培养与鉴定

目的 建立一种新生大鼠大脑皮层神经元原代培养方法.方法 体外原代培养新生大鼠大脑皮质神经元,应用免疫细胞化学法鉴定神经元.结果 用神经基础培养基(Neurobasal-A)+B27培养的神经元纯度可达70%,生长状态较佳.结论 该培养技术是大鼠皮层神经元体外培养的一种较理想的方法.     

运动性心肌肥大大鼠背根神经节降钙素基因相关肽基因表达的变化

目的:探讨运动性心肌肥大大鼠背根神经节降钙素基因相关肽基因表达的变化。方法:雄性SD大鼠随机分为对照组(n=33)和耐力训练组(n=33)。耐力训练组进行10周的跑台耐力训练,建立运动性心肌肥大模型。建模后48h,从两组随机抽取17只大鼠,连续3天进行力竭运动,最后一次力竭运动后即刻处死全部实验动物。记录力竭运动距离和大鼠体重,取大鼠心脏和腰段背根神经节,记录心脏湿重,采用荧光定量聚合酶链式反应技术测定大鼠背根神经节降钙素基因相关肽mRNA的表达量。结果:10周后,耐力训练组大鼠心脏重量与体重之比和力竭运动距离显著高于对照组(P<0.01)。与对照组比较,力竭运动前耐力训练组背根神经节CGRPmRNA表达显著下降(P<0.01),力竭运动后耐力训练组背根神经节CGRPmRNA表达与力竭运动前相比无明显变化,而对照组较力竭运动前显著下降(P<0.01)。结论:运动性心肌肥大大鼠背根神经节CGRP基因表达下调,力竭运动后表达保持稳定。     

局部海水浸泡对SMIR模型大鼠疼痛行为学和继发神经病理改变的影响

目的 评价局部海水浸泡对皮肤/肌肉切口牵拉痛(SMIR)模型大鼠疼痛行为学及继发神经病理改变的影响.方法 选择健康成年雄性SD大鼠48只,随机分为模型对照组(MC组,只建立SMIR模型,不予浸泡处理)、生理盐水浸泡组(NS组,建立模型后局部伤口给予生理盐水浸泡1h)、海水浸泡组(SW组,建立模型后局部伤口给予海水浸泡1h),于术前1d及术后1、3、5、7、14、21、28d测定机械缩足反射阈值(MWT),于术后3、28d各组分别随机取8只大鼠,取术侧隐神经行HE染色、取术侧L3及L4背根神经节应用电镜技术观察其超微结构变化.结果 SW组术后各时点MWT值均明显低于NS组和MC组,且至术后28d仍明显低于术前基础水平;NT组和NS组术后各时点MWT值无明显差异,两组术后28d的MWT值与术前基础水平相当.SW组术后3、28d隐神经HE染色显示均有不同程度的神经损伤表现,而MC组和NS组未见异常;术后3、28d电镜观察见SW组背根神经节神经元内有大量空泡样线粒体和自噬小体,MC组和NS组未见明显病理改变.结论 海水浸泡局部伤口可加重SMIR模型大鼠的急性疼痛,并可能导致其疼痛向慢性化转变,海水浸泡导致的外周神经损伤、背根神经节神经元超微结构改变可能参与了其疼痛行为学改变的机制.     

大鼠坐骨神经损伤对背根节GDNF的表达的影响

目的 应用免疫组化技术观察大鼠坐骨神经条件性损伤对相应背根节及坐骨神经胶质细胞源性神经营养因子（glial cell line-derived neurotrophic factor,GDNF)表达的影响，以探讨GDNF对损伤神经元的作用。方法 45只成年雌性Wistar大鼠随机分为3组：A组（N＝5）正常对照组，B组（N＝20）坐骨神经压榨伤组，C组（N＝20）坐骨神经切断／结扎组；B、C两组按存活期不同再各分为4个亚组，每组5例。大鼠分别于伤后3天、2周、1个月、2个月处死，取材L5节段损伤侧背根节及损伤坐骨神经的远近节段，免疫组化染色观测GDNF表达。结果 （1）正常背根节细胞GDNF表达主要分布于小神经元，少数为大神经元。（2）坐骨神经损伤促使同侧背根节神经元GDNF表达显著增强，伤后2周达到高峰；B组背根节细胞GDNF表达在伤后1个月时轻度下调，伤后2个月恢复为对照组水平。C组背根节细胞GDNF表达保持高水平，并至观察后期2个月。（3）坐骨神经损伤同时诱导背根节卫生细胞及坐骨神经雪旺氏细胞，GNDF表达显著增强，其中远端坐骨神经GDNF表达强于近端。B组这些细胞的阳性表达持续至伤后2周，C组伤后1个月时其表达仍显著。结论 GDNF是参与损伤初级感觉神经元反应的重要因子，并可能对正常及受损背根节细胞发挥营养作用。     

背根神经节解剖及其成像研究进展

神经病理性疼痛是临床常见、多发的疼痛性疾病。背根神经节是神经病理性疼痛形成机制研究的重点,也是疼痛治疗的重要靶区。对背根神经节解剖细节的掌握已成为影响难治性神经病理性疼痛介入疗效的重要因素。就背根神经节解剖及其成像研究进展予以综述。     

腰椎间盘突出症脊神经节三维MR-PROSET影像观测

目的:测量腰椎间盘突出时相应水平脊神经节(DRG)面积的变化,了解它的临床意义.方法:采用3D MR-PROSET序列扫描30例健康志愿者及52例腰椎间盘突出患者,所得原始图像均行3D MIP后处理.测量健康志愿者组L1～S1水平及病例组椎间盘突出受累水平的双侧DRG面积.结果:健康志愿者组的L1～S1水平DRG面积逐...     

组织工程延长后根神经节细胞移植修复脊髓损伤大鼠的长期存活观察

 目的 探索采用组织工程技术,构建由活性轴突形成的较长神经组织移植物,用来修复脊髓损伤.方法 (1)移植物制备:从8~10个15 d胚胎鼠取脊髓后根神经节(doral root ganglion,DRG)细胞,在普通神经细胞培养环境中培养5 d,然后用特制的延长装置将神经节细胞机械拉长,1 mm/d, 2 d,然后增至2 mm/d, 3 d,再减至1 mm/d, 2 d,培养获得10 mm长轴突105~106根,用水凝胶包裹构成神经组织准备移植,移植前用BDA标记轴突及其细胞体.(2)动物模型:成年雌性Sprague-Dawley大鼠225~250 g,40 mg/kg苯巴比妥腹腔注射麻醉,行T9~11双开门手术切除该节段右侧半脊髓约10 mm,同时移植构建好的移植物或单纯移植水凝胶为对照,严密缝合硬膜后行扩大椎板成形术,2个月后处死取标本.(3)免疫组化:纵向连续冷冻切片20 μm/张,行anti-NF200、anti-CGRP(DRG特异)、anti-BDA免疫组化染色.结果 2个月后单纯移植水凝胶者,没有宿主轴突长入水凝胶.移植DRG者,anti-NF200、anti-CGRP、anti-BDA染色均证实2个月后移植细胞存活.结论 组织工程延长后根神经节细胞移植物可以存活达2个月,或有可能在较长的脊髓损伤部位建立上下联系.     

神经生长因子作用于背根神经节细胞过程中神经元基因的表达

目的：探讨神经生长因子（nerve growth factor,NGF)作用于离体培养的背根神经节（dorsal root ganglion,DRG)细胞过程中神经元基因的表达变化。方法：采用逆转录－聚合酶链反应（RT－PCR）方法，观察NGF作用于离体培养的DRG细胞在4，12，24h时，生长相关蛋白43（growth associated protein43,GAP-43)、低分子质量神经丝蛋白(neurofilament,NF-L)、翻译延伸因子2A3－2（a new gene homologous to human translational elongation factor,EF-Ts）基因水平的表达变化，结果：在NGF作用于离体培养的DRG细胞过程中，GAP－43、NF－L、2A3－2基因表达在不同时间呈不同程度的上调。结论：NGF可作用于生长相关蛋白、神经细胞骨架以及相关蛋白翻译水平，促进神经元存活和神经突起延伸。     

Sensory neuronopathy involves the spinal cord and brachial plexus: a quantitative study employing multiple-echo data image combination (MEDIC) and turbo inversion recovery magnitude (TIRM)

Introduction

Sensory neuronopathy (SNN) is a distinctive subtype of peripheral neuropathies, specifically targeting dorsal root ganglion (DRG). We utilized MRI to demonstrate the imaging characteristics of DRG, spinal cord (SC), and brachial plexus at C7 level in SNN.

Methods

We attempted multiple-echo data image combination (MEDIC) and turbo inversion recovery magnitude (TIRM) methods in nine patients with sensory neuronopathy and compared with those in 16 disease controls and 20 healthy volunteers. All participants underwent MRI for the measurement of DRG, posterior column (PC), lateral column, and spinal cord area (SCA) at C7 level. DRG diameters were obtained through its largest cross section, standardized by dividing sagittal diameter of mid-C7 vertebral canal. We also made comparisons of standardized anteroposterior diameter (APD) and left–right diameters of SC and PC in these groups. Signal intensity and diameter of C7 spinal nerve were assessed on TIRM.

Results

Compared to control groups, signal intensities of DRG and PC were higher in SNN patients when using MEDIC, but the standardized diameters were shorter in either DRG or PC. Abnormal PC signal intensities were identified in eight out of nine SNN patients (89 %) with MEDIC and five out of nine (56 %) with T2-weighted images. SCA, assessed with MEDIC, was smaller in SNN patients than in the other groups, with significant reduction of its standardized APD. C7 nerve root diameters, assessed with TIRM, were decreased in SNN patients.

Conclusion

MEDIC and TIRM sequences demonstrate increased signal intensities and decreased area of DRG and PC, and decreased diameter of nerve roots in patients with SNN, which can play a significant role in early diagnosis.     

Morphologic analysis of normal human lumbar dorsal root ganglion by 3D MR imaging

BACKGROUND AND PURPOSE: The dorsal root ganglion (DRG) of the spinal nerve has been considered a key structure in the mechanism of low-back pain and radicular symptoms. The purpose of this study was to clarify the normal morphologic features and variations of the lumbar DRGs in a healthy population by using 3D MR imaging. METHODS: 3D fast-field echo (FFE) with water selective excitation coronal MR images of lumbar spine obtained in 115 healthy volunteers were further reconstructed into a radial stack of 15 coronal images by using maximum intensity projection technique. The DRGs from L1 through L5 were assessed for the location, signal intensity, architecture, and dimensions. RESULTS: Most DGRs were foraminal in location. Only 5.7% of the L5 DGRs were located intraspinally. The sizes of L1, L2, and L5 DRGs in men were larger than those in women (P < .05). The dimensions of the DRGs gradually increased from L1 to L5 (P < .0001). The biganglia (2 ganglial components) frequently occurred in the L4 and L3 DRGs, whereas the singular ganglion (1 ganglial component), in the L5 and L1 DRGs. CONCLUSION: The normal anatomy and variants of the lumbar DRG could be better demonstrated by 3D MR imaging with water selective excitation technique. The relatively larger and more proximally located DRGs in the lower lumbar region may be more susceptible to compression. An appreciation of normal anatomy and variants of DRGs radiologically is helpful for the diagnosis and proper treatment for radiculopathy.     

The radiobiological effectiveness of carbon-ion beams on growing neurons

Purpose: Recently carbon-ion beams have been reported to be remarkably effective for controlling various cancers with less toxicity and are thought to be a promising modality for cancer treatment. However, the biological effect of carbon-ion beams arising on normal neuron remains unknown. Therefore, this study was undertaken to investigate the effect of carbon-ion beams on neurons by using both morphological and functional assays.

Materials and methods: Dorsal root ganglia (DRG) and sympathetic ganglion chains (SYMP) were isolated from day-8 and day-16 chick embryos and cultured for 20 h. Cultured neurons were exposed to carbon-ion beams and X-rays. Morphological changes, apoptosis and cell viability were evaluated with the Growth Cone Collapse (GCC), Terminal deoxynucleotidyl Transferase (TdT)-mediated deoxyUridine TriPhosphate (dUTP) nick End Labeling [TUNEL] assay and 4-[3-(4-iodophenyl)- 2-(4-nitrophenyl)- 2H-5-tetrazolio]- 1,3-benzenedisulfonate [WST-1] assays, respectively.

Results: Irradiation caused GCC and neurite destruction on a time- and irradiation dose-dependent manner. Changes in morphological characteristics were similar following either irradiation. Morphological and functional assays showed that day-8 neurons were more radiosensitive than day-16 neurons, whereas, radiosensitivity of DRG was comparable to that of SYMP. The dose-response fitting curve utilising both GCC and TUNEL labeling index showed higher relative biological effectiveness (RBE) values were associated with lower lethal dose (LD) values, while lower RBE was associated with higher LD values.

Conclusion: Exposure to high-linear energy transfer (LET) irradiation is up to 3.2 more efficient to induce GCC and apoptosis, in early developed neuronal cells, than low-LET irradiation. GCC is a reliable method to assess the radiobiological response of neurons.