不同脊髓损伤模型大鼠行为学及形态学的变化

背景：在脊髓全断模型中有切割伤模型、切除伤模型,为了更好地选择脊髓损伤修复研究的全断动物模型,有必要对这两种模型进行比较及探讨。 目的：分析不同脊髓损伤模型的行为学及病理变化,选择适用于再生研究及治疗的脊髓损伤动物模型。 方法：将160只SD大鼠随机均分为2组,分别制作切割型脊髓损伤模型与切除型脊髓损伤模型,术后1,2,4,8,10,20,30,50周内进行后肢行为学BBB评分及组织化学、免疫组织化学染色,观察损伤区残余纤维情况;术后4,10,26,52周分别在大鼠脑皮质运动区与颈髓注射BDA-FITC示踪剂,观察损伤区残余纤维的连续性。 结果与结论：切割脊髓损伤模型组大鼠术后2-50周双后肢的BBB得分明显高于切除脊髓损伤模型组(P < 0.05);切割脊髓损伤模型组在损伤区残存大量组织和神经丝、胶质纤维酸性蛋白纤维,而切除脊髓损伤模型几乎没有残存纤维;不论是切割脊髓损伤模型还是切除脊髓损伤模型,皮质脊髓束均不能通过损伤区,终止于损伤区的头端;在切割脊髓损伤模型中,脊髓固有束重新进入尾侧端的宿主脊髓组织中,而在切除脊髓损伤模型中脊髓固有束终止于损伤区的头端。表明切除脊髓损伤模型更适用于脊髓损伤后再生效果及治疗手段或药物的筛选与评价。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程      

不同程度脊髓背侧压迫损伤模型大鼠脊髓损伤致伤器的设计

背景：随着对脊髓损伤研究的不断深入,国内外学者不断设计出各种脊髓损伤模型,主要包括脊髓挫伤、重物坠击、脊髓压迫、化学灼伤、放射性损伤及激素横断半横断损伤等,然而各种制备方法都存在一定的局限。 目的：设计脊髓损伤致伤器并建立不同程度脊髓损伤动物模型。 方法：实验自行设计包括致伤部件及传动装置的脊髓损伤致伤器,利用不同致伤质量m1=10 g,m2=20 g,m3=30 g及时间T1=3 s,T2=5 s,造成不同质量×时间暨不同程度SD大鼠脊髓背侧压迫损伤,分为m1T1,m2T1,m3T1,m1T2,m2T2,m3T2共6组,并设假手术组进行对照。 结果与结论：造模后各实验组BBB评分均低于假手术组(P < 0.01),m1T1组与其他各实验组相比差异有显著性意义(P < 0.01),建模后8周m1T2组BBB评分高于与m2T2组及m3T2组(P < 0.05)。建模后8周各组体感诱发电位和运动诱发电位潜伏期明显长于假手术组(P < 0.01)。除了m1T1组与m1T2组外,其他各组间建模后体感诱发电位潜伏期均明显延长(P < 0.05)。所有组建模后运动诱发电位潜伏期均明显延长(P < 0.05)。结果证实,实验所设计的脊髓损伤致伤器可制备出不同程度的脊髓背侧压迫损伤动物模型。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

护理干预对大鼠脊髓损伤后运动功能修复的脊髓形态学研究

目的研究护理干预对大鼠脊髓损伤后脊髓运动功能修复的脊髓形态学变化。方法将60只SD成年大鼠随机分为3组,分别为正常对照组、实验对照组、实验组,每组20只,每组分4个时相点,即脊髓损伤后1 d、7 d、30 d、60 d(n=5)。实验对照组和实验组均采用切割加挤压脊髓L4平面横断制备脊髓损伤大鼠模型。正常对照组为正常大鼠未经处理,实验对照组大鼠脊髓损伤后给予排尿、排便等常规护理,实验组除常规护理之外,还给予关节活动度训练和肌肉按摩训练,每日2次,每次10 min。采用常规HE染色、免疫组织化学染色法观察护理干预对脊髓损伤后大鼠脊髓的形态学变化。结果 HE染色结果以及GFAP和NF-200免疫组织化学染色结果显示,实验组和实验对照组未见明显区别,但与正常对照组比较差异非常明显。结论护理干预对损伤区脊髓组织形态学研究未见明显改变。     

大鼠颈椎骨折错位致脊髓损伤模型的继发性损伤研究

目的　建立大鼠颈椎骨折错位致脊髓继发性损伤模型。 方法　20只成年SD大鼠,随机分为实验组(n=11)和对照组(n=6),3只处死取颈椎测量C4/5水平椎管和椎体矢状径。实验组利用颈椎骨折错位脊髓损伤装置在C4/5之间快速（200 mm/s）错位1.65 mm,造成颈椎骨折错位和颈脊髓损伤,采用自制器械固定颈椎。对照组除未行错位外与实验组相同。术后进行行为学（前肢运动和梳理试验）评价8周,和病理学检查。 结果 实验组行为学评分各个观察时间点均较对照组低。脊髓HE染色切片见实验组脊髓萎缩,灰质破坏,空洞,对照组未见明显异常。实验组损伤中心残留面积（2.79±0.98）mm2,明显小于对照组（6.36±0.08）mm2（P=0.034）。 结论　成功建立了大鼠颈椎骨折错位脊髓继发性损伤模型,大鼠C4/5骨折错位1.65 mm导致明显的脊髓组织损伤和运动功能障碍。     

嗅鞘细胞移植促进脊髓损伤模型大鼠修复损伤区组织的超微结构特征

文题释义： 嗅鞘细胞：是一种嗅神经的支持细胞,它起源于嗅基底膜,分布在嗅球,嗅神经和嗅中枢。位于中枢和外周神经系统过渡区,具有降解抑制再生分子、分泌不同神经营养因子、促进神经轴突和髓鞘的再生、改善脊髓损伤后的微环境等重要作用。 超微结构：通过透射电子显微镜观察脊髓损伤后损伤部位神经元的细胞膜、细胞器(高尔基复合体,尼氏体,内质网、核糖体、神经微丝、微管)、细胞核(核仁、核周体);髓鞘,轴突,突触,胶质瘢痕等亚细胞水平的变化。 背景：嗅鞘细胞移植治疗脊髓损伤是目前的研究热点,其研究主要探讨脊髓损伤后微环境的影响,嗅鞘细胞移植对脊髓损伤后脊髓超微结构的影响未见报道。 目的：观察脊髓损伤后损伤部位神经细胞、轴突、髓鞘、突触和胶质瘢痕的超微结构以及嗅鞘细胞移植对大鼠损伤脊髓的保护和神经修复再生的影响。 方法：实验方案经西安交通大学医学部生物医学伦理委员会批准(批准号2018-2048)。将成年健康雌性SD大鼠20只随机分成3组：空白组(4只)仅仅切除T₁₀全部椎板及T₉, T₁₁部分椎板,未对脊髓作其他处理;DF12组(8只)切断脊髓,注射DF12培养液;嗅鞘细胞移植组(8只)切断脊髓,进行嗅鞘细胞移植。于脊髓损伤后1,7,28,56 d,对各组大鼠麻醉后取出脊髓,透射电镜观察脊髓损伤区神经细胞超微结构的变化。 结果与结论：①与空白组比较,DF12组大鼠脊髓损伤区神经元胞体内细胞器明显减少,轴突、髓鞘和突触的超微结构发生明显的变化;嗅鞘细胞移植组损伤区的神经元胞体内细胞器明显增加,核仁明显,促进轴突、髓鞘和突触的再生,且胶质瘢痕明显较少;②嗅鞘细胞移植组大鼠星形胶质细胞和毛细血管周细胞的反应比较轻微;③结果说明,脊髓损伤后嗅鞘细胞移植可有效地保护脊髓损伤区的神经组织,促进轴突、髓鞘和突触的再生,抑制神经胶质和周围细胞的增生反应,从而使损伤后微环境有利于神经元、轴突和突触再生。ORCID: 0000-0001-6049-2551(王国毓) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

海人藻酸致大鼠脊髓损伤模型的光镜和电镜研究

用成年Ｗｉｓｔａｒ大鼠７０只，雌雄不拘，通过向腰髓内注射海人藻酸（５μｌ，０．００１ｍｏｌ／Ｌ）建立了脊髓内注射神经毒导致大鼠脊髓损伤的动物模型；一部分向脊髓内注射盐水做为对照．动物按注射后存活２ｈ、６ｈ、１２ｈ、２４ｈ、３ｄ、６ｄ和１４ｄ分组．Ｎｉｓｓｌ染色，电镜观察。注射后２４ｈ内，脊髓腹角神经元出现进行性细胞肿胀，尼氏作皱缩深染，形成许多微细的空泡，胞核浓缩。电镜下观察到内质网、线粒体和高尔基氏体的肿胀和胞质内的空泡和树突的膨胀．注射后３～６ｄ，神经细胞发生明显的退变，细胞质浓缩，尼氏体分解，早期病变的小空泡形成较大的空洞，核偏移。６ｄ后大部分细胞死亡，尚存的脊髓运动神经元明显肿胀，细胞核的边界不清，尼氏体完全消失，电镜下显示细胞器完全被破坏，胞质内的空洞进一步融合形成几个大空洞，细胞核继续浓缩。１４ｄ后注射部位的运动神经元几乎完全消失，胶质细胞明显增生。作为谷氨酸受体激动剂的海人藻酸导致脊髓运动神经元的急性溃变，可作为除撞击、压迫、缺血或横断所致脊髓损伤以外的又一种动物模型，其损伤的病理变化以神经元退变为主，而脊髓的完整性不受破坏，类似于脊髓灰质炎的病变，适用于神经细胞移植的研究。     

BYHWD对脊髓损伤大鼠脊髓组织Bcl-2和Bax表达的影响

目的:观察补阳还五汤(buyanghuanwu decoction,BYHWD)对脊髓损伤(spinal cord injury,SCI)模型大鼠脊髓神经细胞凋亡相关蛋白Bcl-2、Bax及其mRNA表达的影响,初步探讨BYHWD抑制脊髓神经细胞凋亡的作用机制。方法:Wistar大鼠40只,随机分为四组:正常对照组、SCI模型组、BYHWD组和甲基强的松龙(MP)注射组,每组10只大鼠;后三组动物先建立SCI损伤模型,然后分别给予BYHWD组和MP组BYHWD和MP治疗。四组动物分别于术后1、7、14、21 d和28 d对大鼠后肢神经功能的恢复情况进行BBB(Basso-Beattie-Bresnahan)功能评分。第28 d处死各组大鼠,采用Real-time PCR法检测脊髓组织Bcl-2和Bax mRNA的表达情况,Western Blot法检测脊髓组织Bcl-2和Bax蛋白的表达情况。结果:大鼠麻醉清醒后,SCI组大鼠损伤平面以下完全瘫痪。BBB评分结果显示:术后第7 d~28 d,与正常对照组相比,SCI组BBB评分明显降低(P0.05);与SCI组相比,BYHWD处理组和MP处理组大鼠BBB评分明显增高(P0.05),但BYHWD处理组和MP处理组大鼠相比,BBB评分无明显差异(P0.05)。Real-time PCR和Western Blot结果显示:与正常对照组相比,SCI组Bax蛋白及mRNA的表达明显升高(P0.05),而Bcl-2蛋白及mRNA的表达则明显有所降低(P0.05)。与SCI组相比,BYHWD处理组和MP处理组大鼠脊髓组织Bax蛋白及mRNA表达明显降低(P0.05),而Bcl-2蛋白及mRNA表达则明显有所升高(P0.05)。但BYHWD处理组和MP处理组大鼠脊髓组织Bcl-2、Bax蛋白及mRNA表达之间无明显差异(P0.05)。结论:BYHWD可以改善SCI大鼠后肢的运动功能,通过下调Bax的表达,上调Bcl-2的表达,从而抑制SCI大鼠脊髓神经细胞的凋亡,发挥其保护作用。     

脊髓损伤大鼠内皮祖细胞与脊髓血管新生

背景：诸多脑损伤实验表明,改善损伤组织缺血缺氧有助于促进损伤组织的修复,并有保护神经功能的目的。 目的：探讨挫伤型脊髓损伤后大鼠外周血中内皮祖细胞的变化及其与创伤灶周围早期血管新生情况的关系。 方法：成年雄性SD大鼠60只,随机数字表法均分为实验组与对照组。实验组采用Allen’s原理制作脊髓损伤模型,对照组只行椎板切除暴露脊髓,不予打击致伤。分别于术前及术后3,6,24,48,72,168 h取大鼠外周血,流式细胞仪检测外周血中内皮祖细胞数量。并于术前及术后1,4,7,14 d处死大鼠取脊髓,采用血管内皮标志物CD31免疫组化染色方法观察创伤区血管的新生情况。 结果与结论：两组大鼠外周血内皮祖细胞水平于伤后3 h均有所下降,6 h开始上升,24 h达高峰,随后逐渐达稳定水平。实验组高峰值明显高于对照组。同时微血管数量呈逐渐增多的趋势。说明大鼠脊髓损伤后,外周血内皮祖细胞数量明显增加,内皮祖细胞参与血管新生和损伤组织的修复,最终促进神经功能恢复。     

新生大鼠心肌组织Telocytes的组织形态学研究

本研究以新生大鼠心肌组织为研究对象,分别采用组织学、免疫组织化学及甲苯胺蓝染色方法,对新生大鼠心肌组织中telocytes形态特征和免疫标志进行观察与分析.其中,组织学染色与甲苯胺蓝染色结果显示,新生大鼠心肌组织中存在大量间质细胞,其中telocytes的分布多紧贴于心肌纤维束周围或纤维之间,细胞呈现长梭形、纺锤形及三角形等多种形态,胞质少、有一至多条长而细的细胞突起,胞核结构较致密、着色较深.免疫组化染色结果进一步证实新生大鼠心肌组织中其不但表达间质细胞的免疫标志vimentin,有些还表达c - kit/CD117和CD34两种与干细胞相关的表面标志物.本研究从组织形态学的角度阐明了telocytes的基本特征和分布,为进一步揭示其功能奠定了在体形态结构上的基础.     

局部注射布比卡因建立大鼠骨骼肌损伤模型的组织形态学评价

BACKGROUND: The neurotoxicity and cardiotoxicity of bupivacaine have been reported frequently. However, the studies on bupivacaine-induced muscle toxicity are few.     

Electromechanical impactor for producing experimental spinal cord injury in animals

Previous experiments indicated that the mechanical properties (compliance and mobility) of spinal cord tissue vary by ±50 per cent from the mean in different individuals of the same species. In order to apply a consistent force or compression to tissues of varying mechanical properties, feedback control of the contusion device would be desirable. A new device has been designed and used by the author which will produce experimental spinal cord injuries in animals by direct contusion of the exposed cord. The motion of the impact head is feedback controlled through all phases of advance, compression and withdrawal. Force and displacement are recorded in computer random access memory for later processing and graphical printout. A wide range of impact intensities and resultant injuries are achievable. The correlation coefficients between linear compression of the cord and gait scores and lesion volume range from 0·70 to 0·89. Thus, the neural deficit is highly predictable from the impact parameters. This should result in a significant reduction in the number of animals needed in any one experimental group.     

实验用脊髓腹侧损伤撞击器的设计及应用*☆

背景：目前脊髓损伤的基础研究主要依赖于动物损伤模型,每种脊髓损伤模型都有其适应范围及不足之处。 目的：设计并制造实验用大鼠脊髓腹侧损伤撞击器,并在大鼠脊髓损伤实验中验证仪器的使用效果。 方法：设计脊髓腹侧损伤撞击器的图纸,并按图纸组装成成品;应用该仪器制作SD大鼠脊髓腹侧损伤模型。随机分为3组,中度损伤组用23 V电压的打击力量,重度损伤组用25 V电压打击力量,对照组在安装撞击钩后,不实施打击。 结果与结论：重度损伤组BBB评分明显低于中度损伤组(P < 0.001)。BBB评分与脊髓残留组织呈线性相关(P < 0.001),     23 V电压力量30%的脊髓变形率可以制作中度脊髓损伤模型,25 V电压力量61%的脊髓变形率可以制作重度脊髓损伤模型。证实实验设计的脊髓腹侧损伤仪器能够制作大鼠脊髓腹侧中、重度损伤模型,损伤力量大小方便可控,脊髓形变可测。     

Response characteristics of spinal cord dorsal horn neurons in chronic allodynic rats after spinal cord injury

The physiological mechanisms of chronic pain in patients with spinal cord injury (SCI) are poorly understood. In the present study, we explored response characteristics of dorsal horn neurons of spinally injured rats exhibiting chronic pain (pain-like response to innocuous mechanical and cold stimulation). Several abnormalities were found in the distribution and response characteristics of dorsal horn neurons in chronic allodynic rats. First, 17% of the recorded neurons (vs. 0% in control animals) had no receptive field. Most of these units were located at or close to the lesioned spinal segment, and they discharged spontaneously at high frequencies. Allodynic rats also showed a significant decrease in the proportion of low-threshold (LT) neurons and an increase in the proportion of wide dynamic range (WDR) neurons. The rate of spontaneous activity of high-threshold (HT) neurons was significantly higher in allodynic compared with control rats. Moreover, HT neurons in allodynic animals showed increased neuronal responses to mechanical stimulation. WDR neurons responded with higher discharge rates to innocuous von Frey hair stimulation in allodynic compared with control rats. The percentage of WDR and HT neurons showing afterdischarges to noxious pinch was also significantly increased in the allodynic rats. The proportion of WDR and HT neurons responding to innocuous cold stimulation respectively increased from 53 and 25% in control rats to 91 and 75% in allodynic animals. These results suggest that the chronic pain-like behaviors in spinally injured rats may be generated and maintained by abnormalities in dorsal horn neurons.     

SHH缓释的脊髓去细胞支架促进大鼠脊髓损伤修复

目的:研究可缓释音猬因子(sonic hedgehog,SHH)的脊髓去细胞支架(acellular spinal cord scaffolds,ASCSs)对大鼠脊髓损伤修复的效果。方法:(1)用物理和化学联合法制备ASCSs,并检测其效果。(2)使用京尼平(genipin,GP)作为交联剂,体外制备缓释SHH的ASCSs(ASCSs-GP-SHH),探究其缓释效果。(3)建立大鼠脊髓损伤(spinal cord injury,SCI)模型,随机分为四组(每组20只):单纯SCI组,ASCSs组,ASCSs-GP组(GP交联的ASCSs),ASCSs-GP-SHH组。术后每周记录BBB评分,评估功能恢复。术后12周取出损伤处脊髓组织,行免疫组化和Western Blot检测损伤处相关蛋白Nestin(巢蛋白),GAP43(生长相关蛋白),MBP(髓磷脂碱性蛋白),NF200(神经丝蛋白),GFAP(胶质纤维酸性蛋白)的表达。结果:(1)物理及化学联法制备ASCSs效果良好;(2)ASCSs-GP-SHH具有良好的缓释SHH的性能;(3)ASCS-GP-SHH组BBB评分从术后到12周较其他组高(P0.05);(4)免疫组化及HE染色结果显示:ASCS-GP-SHH组脊髓横断处有神经元再生。SCI组神经元凋亡明显,纤维瘢痕及空洞大,ASCS-GP组较ASCS组稍好,ASCS组较SCI组稍好;(5)Western Blot结果显示:ASCS-GP-SHH组Nestin,GAP43,MBP,NF200表达高于SCI、ASCS-GP、ASCS组(P0.05),而GFAP低于SCI、ASCS-GP、ASCS组(P0.05)。结论:物理和化学联合制备可以有效的制备ASCSs,ASCSs-GP-SHH缓释效果良好,对大鼠脊髓损伤的修复有明显的促进作用。     

脊髓全横断大鼠模型的构建

背景：脊髓全横断模型在造模时常难以保证神经纤维的完全离断。 目的：构建大鼠脊髓全横断损伤模型。 方法：将大鼠随机分为模型组和假手术组。模型组构建脊髓T10节段全横断模型;假手术组动物仅打开椎管与硬脊膜而后缝合,但不损伤脊髓。建模后1,3,5,7 d分别进行BBB评分以评估后肢运动功能,检测其体感诱发电位和运动诱发电位来评估神经传导通路的完整性,并行形态学观察来评估脊髓肉眼观病理形态。 结果与结论：与假手术组相比,模型组大鼠在建模后1,3,5,7 d时,其BBB评分降低(P < 0.01),未检测出体感和运动诱发电位。形态学观察结果显示模型组大鼠脊髓完全横断,而假手术组脊髓形态完整。结果提示实验成功构建了大鼠脊髓全横断模型。     

脊髓压迫性损伤大鼠海马和脊髓内BDNF的表达变化

目的探讨脑源性神经营养因子(BDNF)在脊髓压迫性损伤后的表达变化及作用。方法用自行设计的方法制作脊髓压迫模型,免疫荧光检测BDNF在星形胶质细胞、神经元和上下行轴突的表达;WB检测BDNF在大鼠海马及脊髓的表达。结果随着时间延长,受损部位的BDNF+-GFAP荧光强度逐渐增强;BDNF+-Tuj1荧光强度逐渐减弱;受损部位相邻上下段的BDNF+-NF200比受损部位的明显增强。海马和脊髓受损中心相邻的上、下段的BDNF蛋白表达在损伤后1d达到峰值,然后逐渐下降(P0.05);而脊髓受损中心的BDNF蛋白表达逐渐下降(P0.05)。结论脊髓损伤后,BDNF的表达下调,随伤后时间呈一定规律变化,是引起受损部位神经元表达下降的原因之一。     

Repair of thoracic spinal cord injury by chitosan tube implantation in adult rats

Spinal cord injury (SCI) is a common outcome of traffic accidents and trauma with severe consequences. There has been no cure for such a condition. We performed experiments to evaluate the feasibility of implanting a chitosan tube filled with semifluid type I collagen into the site of surgically induced SCI to facilitate functional recovery. After a segment of the spinal cord, 4 mm in length and 2/3 of the spinal cord across its width, at the ninth thoracic level of an adult rat was dissected and removed, the biodegradable chitosan tube was implanted into the lesioned site. One year later, we found that axons from the proximal spinal cord regenerated, traversed the dissected area inside the tube and reentered the distal spinal cord, leading to functional restoration of the essentially paralyzed hind limbs. The nerve regeneration and functional recovery were confirmed by immunohistochemistry, electron microscopy, nerve tracing and Basso–Beattie–Bresnahan behavioral evaluation. Such beneficial outcomes were not observed in the control groups, in which either no tube was implanted or the implanted tube had no collagen filling. We conclude that the newly designed tube implant promotes both axon regeneration and functional recovery following SCI. A similar approach may have clinical implications in humans.     

SD大鼠脊髓损伤后微环境的模拟实验

BACKGROUND: We built Sprague-Dawley rat models with mild, moderate, and severe spinal cord injuries to accord with the spinal cord injury types for basic empirical study, and consequently to further understand the microenvironmental change in Sprague-Dawley rats with spinal cord injury, and to provide help for clinical treatment. OBJECTIVE: To observe the changes in nerve function, pathological manifestation and motor sensory evoked potential in Allen’s models and Sprague-Dawley rats with complete spinal cord transection at different time points after spinal cord injury by simulating the microenviroment in Sprague-Dawley rats. METHODS: A total of 125 healthy adult female Sprague-Dawley rats were selected and randomly divided into group sham operation group, 100 gcf hit potential group (20 g×5 cm), 200 gcf hit potential (20 g×10 cm), 300 gcf hit potential group (20 g×15 cm), and spinal cord complete transection group with 25 rats in each group. At 1, 5, 7, 14 and 28 days after model establishment, the degree of spinal cord injury was identified by the BBB scores of motion function, motor evoked potential, and pathological section. RESULTS AND CONCLUSION: (1) Totally 24 Sprague-Dawley rats died in the experiment. The death rate and the rate of complications were highest in the spinal cord complete transection group. The BBB score of each group was decreased. The BBB scores in every group increased as time went on. There were significant differences between each surgery group and the sham operation group at corresponding time points (P < 0.05).  No significant difference was found between the 300 gcf hit potential group and the spinal cord complete transection group at corresponding time points (P > 0.05). (2) In each surgery group, the infiltration of inflammatory cells and obvious swelling of neurons were visible at 1 day after injury. Neural cells reduced with time prolonged. At 28 days after injury, a large number of astrocytes proliferated, scar and spinal cord cavity formed. Above symptoms were worse in the 300 gcf hit potential group and spinal cord complete transection group than in the 100 gcf and 200 gcf hit potential groups. (3) Significant differences in amplitude and latency were detectable between each surgery group and the sham operation group (P < 0.05). No significant difference in amplitude and latency was detected between the 300 gcf hit potential group and the spinal cord complete transection group at corresponding time points (P > 0.05). Results confirmed that hit potential of 20 g×5 cm, 20 g×10 cm and 20 g×15 cm can simulate the microenvironment of Sprague-Dawley rats with mild, moderate and severe spinal cord injury. The rate of complication was lower in modified Allen’s model of different hit potentials than in models of spinal cord complete transection, and was more accorded with basic research.       

NG2细胞在大鼠脊髓压迫性损伤急性期内源性增殖及形态变化规律

目的　研究NG2细胞在大鼠脊髓损伤白质内源性增殖及形态特征。 方法　成年SD雄性大鼠42只,随机平均分为模型组和假手术组。按课题组自行设计的方法制作脊髓压迫模型,假手术组仅暴露脊髓。分别于术后1、3、7d运用免疫组化检测脊髓内NG2细胞的表达。采用Image Pro Plus6.0软件对NG2阳性细胞计数并测量其胞体面积和突起长度。 结果　伤后1d,NG2+细胞增多（30.17±11.08）/视野,至3d达到高峰(90.75±9.40) /视野,7d后下降（78.38±8.91）/视野,但仍多于假手术组（19.92±6.68）/视野（P＜0.05）。在假手术组,NG2+细胞平均胞体面积为（205.67±10.80）μm2、平均突起长度为（22.92±1.24）μm,伤后1d,NG2+细胞胞体变小（128.25±32.06）μm2、突起变短(10.98±4.25) μm,3d后胞体变大(225.26±　16.64) μm2、突起增长(18.63±2.26) μm（P＜0.05）,至7d变化不明显（P＞0.05）。在脊髓压迫损伤后,可见许多胞体较小呈圆形、突起少或无的NG2+细胞集落。 结论　在脊髓压迫损伤一周内,NG2细胞增殖活跃,胞体渐大,突起变长,但仍短于正常。