Effect of artificial gravity in space flight on the content of water-soluble proteins in nerve tissue structures

The content of water-soluble proteins was investigated in the gray and white matter of the spinal cord, the spinal ganglia, and the sensomotor cortex of rats after a space flight lasting 18.5 days. The content of water-soluble proteins in the gray and white matter of the spinal cord and in the spinal ganglia of rats exposed to the action of weightlessness was significantly reduced after 4.5–9.5 h. In rats kept under conditions of artificial gravity during flight the content of water-soluble proteins was reduced in the white matter of the spinal cord. In animals kept previously under conditions of weightlessness 25 days after space flight a significant increase was found in the level of, water-soluble proteins in the gray matter of the spinal cord. In the gray matter of the sensomotor cortex of rats kept under conditions of weightlessness or of artificial gravity no changes were found (compared with controls kept in the ordinary animal house) in the content of water-soluble proteins whether 4.5–9.5 or 25 days after the satellite has landed.Institute for Medico-Biological Problems, Ministry of Health of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 10, pp. 421–424, October, 1978.     

Glia to neuron ratio in the posterior aspect of the human spinal cord at thoracic segments relevant to spinal cord stimulation

Spinal cord stimulation (SCS) applied between T8 and T11 segments has been shown to be effective for the treatment of chronic pain of the lower back and limbs. However, the mechanism of the analgesic effect at these medullary levels remains unclear. Numerous studies relate glial cells with development and maintenance of chronic neuropathic pain. Glial cells are electrically excitable, which makes them a potential therapeutic target using SCS. The aim of this study is to report glia to neuron ratio in thoracic segments relevant to SCS, as well as to characterize the glia cell population at these levels. Dissections from gray and white matter of posterior spinal cord segments (T8, T9, intersection T9/T10, T10 and T11) were obtained from 11 human cadavers for histological analyses. Neuronal bodies and glial cells (microglia, astrocytes and oligodendrocytes) were immunostained, microphotographed and counted using image analysis software. Statistical analyses were carried out to establish significant differences of neuronal and glial populations among the selected segments, between the glial cells in a segment, and glial cells in white and gray matter. Results show that glia to neuron ratio in the posterior gray matter of the human spinal cord within the T8–T11 vertebral region is in the range 11 : 1 to 13 : 1, although not significantly different among vertebral segments. Glia cells are more abundant in gray matter than in white matter, whereas astrocytes and oligodendrocytes are more abundant than microglia (40 : 40 : 20). Interestingly, the population of oligodendrocytes in the T9/T10 intersection is significantly larger than in any other segment. In conclusion, glial cells are the predominant bodies in the posterior gray and white matter of the T8–T11 segments of the human spinal cord. Given the crucial role of glial cells in the development and maintenance of neuropathic pain, and their electrophysiological characteristics, anatomical determination of the ratio of different cell populations in spinal segments commonly exposed to SCS is fundamental to understand fully the biological effects observed with this therapy.     

紫外线照射充氧自血回输对家兔脊髓损伤后血液循环的影响

家兔用改良Allen 氏系统造成不完全性脊髓损伤,随机分为对照组、损伤组和治疗组。分别测定血液和脊髓组织TXB 2、 6-keto-PGF 1 a 和ET-1 含量;以及脊髓组织灰质、白质和总血流量,研究紫外线照射和充氧自血回输疗法（UBIO）治疗脊髓损伤的作用机制。实验发现：损伤组血液和脊髓组织TXB 2 含量升高、6-keto-PGF 1 a 含量下降、ET-1 含量升高。脊髓组织灰质和白质血流量以及脊髓组织总血流量均下降。治疗组用UBIO 治疗后,血液和脊髓组织TXB 2 含量下降、6-keto-PGF 1 a 含量升高、ET-1 含量下降。脊髓组织灰质和白质血流量以及脊髓组织总血流量均上升。实验说明：UBIO 可以改善全身和脊髓组织的血液循环。     

Morphofunctional characteristics of the lumbar enlargement of the spinal cord in rats

The topography of the lumbar enlargement of the spinal cord in rats was studied; an immunohistochemical method was used to determine the distribution of synaptophysin — a membrane protein of synaptic vesicles. Synaptophysin-immunoreactive structures were detected in the gray matter of all Rexed laminae, around most neurons and in the neuropil. Previously undescribed subpial synaptic contacts were detected immunohistochemically in the white matter and confirmed by electron microscopy. A non-myelinated component of the corticospinal tract, including axonal varicosities and synaptic contacts, was observed in the dorsal part of the white matter of the lumbar enlargement of the spinal cord. __________ Translated from Morfologiya, Vol. 132, No. 5, pp. 33–37, September–October, 2007.     

基于病理切片延髓-上颈髓三维有限元模型的建立及其损伤生物力学分析

目的 基于标本病理切片数据,建立延髓-上颈髓三维实体模型,通过有限元分析获得延髓-上颈髓受齿状突压迫情况下应力、应变水平,为临床研究提供参考.方法 运用Mimics对切片数据进行处理,建立点云模型;运用SolidWorks对点云模型进行定位、编辑、优化,建立三维实体模型;运用HyperMesh建立有限元模型并运用ANS...     

Axonal loss in the multiple sclerosis spinal cord revisited

Preventing chronic disease deterioration is an unmet need in people with multiple sclerosis, where axonal loss is considered a key substrate of disability. Clinically, chronic multiple sclerosis often presents as progressive myelopathy. Spinal cord cross‐sectional area (CSA) assessed using MRI predicts increasing disability and has, by inference, been proposed as an indirect index of axonal degeneration. However, the association between CSA and axonal loss, and their correlation with demyelination, have never been systematically investigated using human post mortem tissue. We extensively sampled spinal cords of seven women and six men with multiple sclerosis (mean disease duration= 29 years) and five healthy controls to quantify axonal density and its association with demyelination and CSA. 396 tissue blocks were embedded in paraffin and immuno‐stained for myelin basic protein and phosphorylated neurofilaments. Measurements included total CSA, areas of (i) lateral cortico‐spinal tracts, (ii) gray matter, (iii) white matter, (iv) demyelination, and the number of axons within the lateral cortico‐spinal tracts. Linear mixed models were used to analyze relationships. In multiple sclerosis CSA reduction at cervical, thoracic and lumbar levels ranged between 19 and 24% with white (19–24%) and gray (17–21%) matter atrophy contributing equally across levels. Axonal density in multiple sclerosis was lower by 57–62% across all levels and affected all fibers regardless of diameter. Demyelination affected 24–48% of the gray matter, most extensively at the thoracic level, and 11–13% of the white matter, with no significant differences across levels. Disease duration was associated with reduced axonal density, however not with any area index. Significant association was detected between focal demyelination and decreased axonal density. In conclusion, over nearly 30 years multiple sclerosis reduces axonal density by 60% throughout the spinal cord. Spinal cord cross sectional area, reduced by about 20%, appears to be a poor predictor of axonal density.     

Noninvasive detection of brainstem and spinal cord axonal degeneration in an amyotrophic lateral sclerosis mouse model

Degeneration of motor neurons and their associated axons is a hallmark of amyotrophic lateral sclerosis, but reliable noninvasive lesion detection is lacking. In vivo diffusion tensor imaging was performed to evaluate neurodegeneration in the brainstem and cervical spinal cord of wild-type and G93A-SOD1 transgenic mice, an animal model of amyotrophic lateral sclerosis. A statistically significant reduction in the apparent diffusion coefficient was observed in the motor nuclei VII and XII of G93A-SOD1 transgenic mice relative to wild-type mice. No significant difference in diffusion anisotropy was observed in dorsal white or gray matter in cervical and lumbar segments of the spinal cord. In contrast, statistically significant decreases in axial diffusivity (diffusivity parallel to the axis of the spinal cord) and apparent diffusion coefficient were found in the ventrolateral white matter of G93A-SOD1 mice in both the cervical and lumbar spinal cord. The reduction in axial diffusivity, suggestive of axonal injury, in the white matter of the spinal cord of G93A-SOD1 mice was verified by immunostaining with nonphosphorylated neurofilament. The present study demonstrates that in vivo diffusion tensor imaging-derived axial diffusivity may be used to accurately evaluate axonal degeneration in an animal model of amyotrophic lateral sclerosis.     

龟龄集对大鼠脊髓灰质内突触小泡蛋白变化的影响

目的：研究龟龄集对大鼠脊髓灰质内突触小泡蛋白的影响，探索龟龄集的抗衰老功效。方法：采用免疫组织化学结合图像分析法，对龟龄集喂药鼠和对照鼠的脊髓颈膨大、胸髓、腰膨大和骶尾髓灰质内突触小泡蛋白的免疫反应产物进行了观测。结果：对照和喂药鼠各自的脊髓各段后角内突触小泡蛋白免疫反应产物的灰度值不同，均以脊髓胸段最小，腰膨大最大；脊髓后角内免疫反应产物的灰度值均低于前角。对照组脊髓各段后角内突触小泡蛋白免疫反应产物的灰度值均明显高于喂药组。结论：龟龄集可延缓神经元的衰老，防止脊髓灰质内突触小泡蛋白的丢失，增强动物肢体感觉的灵敏性和活动的灵活性。     

Sexual dimorphism of the human spinal cord in the aging process

There have been few morphometric studies on age-related changes in the human spinal cord. The purpose of the present study was to determine the existence of sexual dimorphism of the spinal cord between males and females during the aging process. Spinal cords were removed from cadaver specimens, 26 males and 22 females for anatomic practice, the age at death ranged from 41 to 97 years for males (average, 71.5 years) and from 59 to 92 years for females (average, 76.6 years). Spinal cord segments were embedded in celloidin after secondary fixation and dehydration. Sections were stained with the Luxol fast blue-periodic acid-Schiff-hematoxylin and Klüver-Barrera methods. Morphometric analysis was performed with an electronic optical planimeter and a computer. Each section was enlarged 13.5 times to take a picture. The areas of the transverse section white matter and gray matter of the spinal cord at segments C5 and L3 were measured. Although there was no correlation between the total transverse area of the spinal cord and age either in males or females, we noticed that the area of the gray matter decreased faster in males than in females; while the area of the white matter decreased faster in females than in males. The area ratio of the white matter to the whole segment area of the spinal cord (W/T) at level C5 is larger in males than that in females. Our results suggest that there could be a difference between males and females in changes in the white and gray matters of the spinal cord due to aging.     

The spinal cord development in guinea pig: a morphometric study on an image analysis system

Using an image analysis system, the Authors carried out a morphometric study on guinea pig spinal cord in order to determine volumetric changes of white and gray matter during development. White and gray matter volumes were determined by measuring the area occupied by these matters in 10 micrograms sections of spinal cord in 1 day and 90 days old subjects. Several topographic correspondences in the localisation of the lowest and highest volumetric values were observed in the two groups of subjects. Such correspondences were more marked for white than gray matter. Moreover, during growth white matter volume showed an increase double that observed in gray matter.     

脊髓血供的计量学观察

目的 :探讨脊髓内部血管构筑和分布 ,为脊髓缺血性的有关病变、治疗和预后提供形态学基础。方法 :应用碱性磷酸酶血管染色法 ,对脊髓内部血管 ,用体视学方法作计量和观察。结果 :在脊髓内部灰、白质的毛细血管体密度 ,表面积密度、长度密度存在着差异。结论 :灰质内毛细血管的体密度 ,表面积密度、长度密度均明显高于白质 ,灰质前角的毛细血管量明显多于后角 ,而白质毛细血管的体密度是 :前索 >侧索 >后索     

体感诱发电位评价慢性压迫性脊髓症神经功能的病理机制

目的 探讨慢性压迫性脊髓症不同体感诱发电位(somatosensory evoked potential,SEP)变化对应的病理学机制.方法 20只SD大鼠经后路手术、颈椎管内(C5～C6水平)植入吸性聚氨酯胶片,该植入体在硬膜外逐渐吸水膨胀,形成对脊髓的慢性持续压迫.术前和造模后6个月检测SEP,并对慢性压迫脊髓行Micro-CT、组织学(HE染色)和组织化学(FLB染色)检测.结果 20只造模大鼠脊髓均出现侧后方明显压迫性形态学改变,Micro-CT显示脊髓灰质和白质扭曲变形.依据SEP变化分为Ⅰ(n=6)、Ⅱa(n=5)、Ⅱb(n=4)、Ⅲ(n=5)、Ⅳ(n=0)5类.SEP异常者脊髓后索髓鞘FLB染色显著减少(SEP异常:106±27;SEP正常:121±8;P=0.036),Micro-CT显示脊髓后索对比剂密度明显增加(SEP异常:95±5;SEP正常:87±6;P=0.041),后角内神经元也明显较少[SEP异常:(21±8)/mm2;SEP正常:(29±6)/mm2;P＞0.05].病理学上,SEP-Ⅰ型表现为脊髓中央管扩大;Ⅱa型表现为灰质内出血、静脉扩张和中央管缩小;Ⅱb型表现为灰质、白质排列紊乱,血管增生;Ⅲ型表现为神经元明显减少、白质-灰质结构不清,基质海绵样变.结论 慢性压迫性脊髓症不同类型的SEP变化反映了脊髓后索和灰质神经元损伤的严重程度,SEP作为脊髓功能预后评估的判断指标具有相应的病理学特征.     

大鼠脊髓发育过程中神经干细胞的分化

目的:研究正常大鼠脊髓发育过程中神经干细胞的分化规律。方法:应用免疫荧光染色技术,检测Nestin、NeuN、MAP2、GFAP、CNPase阳性细胞在大鼠胚胎期及生后脊髓内的分布及变化情况。结果:胚胎发育早期,脊髓中央管、灰质、白质均可检测到Nestin阳性细胞,生后Nestin阳性细胞数量逐渐减少。大鼠脊髓神经元的发生呈现明显的背腹模式,孕14d(E14)脊髓内可检测到NeuN阳性细胞,E16 NeuN阳性细胞逐渐增多,腹侧NeuN阳性细胞核体积较大,分布较稀疏,背侧神经元细胞核体积较小,分布较密集。MAP2染色结果与NeuN一致。胶质细胞的分化、成熟在生后初期进行,P4可检测到GFAP及CNPase阳性细胞,主要分布于脊髓白质内,P30在脊髓灰质内可检测到GFAP阳性细胞,细胞分支较多且短。结论:正常大鼠脊髓发育中神经干细胞的分化呈现一定规律性,向神经元方向化较早且呈明显的背腹模式,胶质细胞的分化较晚。     

Limited minocycline neuroprotection after balloon-compression spinal cord injury in the rat

Minocycline (MC), a second-generation tetracycline and anti-inflammatory agent reportedly provides neuroprotection following CNS injury. The objective of this study was to examine the neuroprotective effects of short and long-term MC treatment using balloon-compression spinal cord injury (SCI) in the rat. Rats subjected to SCI were treated with MC for 1 day (1DMC group; total dose 180 mg/kg) or 5 days (5DMC group; total dose 450 mg/kg) or placebo. The effects of MC treatment on locomotor recovery (BBB scale) and spinal cord white and gray matter sparing were evaluated for up to 28 days. Morphometric analysis showed that while MC treatment spared spinal cord white and gray matter rostral to the lesion epicenter in both, 1DMC and 5DMC groups, sparing of white and gray matter areas was not observed caudal to the traumatic lesion. In addition, MC treatment had no effect on final locomotor recovery. Limited improvement of spinal cord post-compression consequences raises questions about the neuroprotection efficiency of MC treatment following compression SCI in the rat.     

T-激肽原在大鼠腰骶髓及背根节的分布

目的 探讨T-激肽原在神经系统的定位及作用.方法 应用免疫细胞化学方法,结合光镜观察.本实验研究了T-激肽原在大鼠腰骶髓及L_(4-6)背根节的分布.结果T-激肽原分布于L_(4-6)背根节及腰骶髓灰质的第Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅸ层神经元及脊髓白质的神经胶质细胞和神经纤维.结论 在上述部位的神经元和神经胶质细胞,T-激肽原和高分子量激肽原、低分子量激肽原及其代谢产物可能共存.     

Early and extensive spinal white matter involvement in neuromyelitis optica

ObjectivesStudies of longitudinally extensive spinal cord lesions (LESCLs) in neuromyelitis optica (NMO) have focused on gray matter, where the relevant antigen, aquaporin‐4 (AQP4), is abundant. Because spinal white matter pathology in NMO is not well characterized, we aimed to clarify spinal white matter pathology of LESCLs in NMO.MethodsWe analyzed 50 spinal cord lesions from eleven autopsied NMO/NMO spectrum disorder (NMOSD) cases. We also evaluated LESCLs with three or fewer spinal cord attacks by 3‐tesla MRI in 15 AQP4 antibody‐positive NMO/NMOSD patients and in 15 AQP4 antibody‐negative multiple sclerosis (MS) patients.ResultsPathological analysis revealed seven cases of AQP4 loss and four predominantly demyelinating cases. Forty‐four lesions from AQP4 loss cases involved significantly more frequently posterior columns (PC) and lateral columns (LC) than anterior columns (AC) (59.1%, 63.6%, and 34.1%, respectively). The posterior horn (PH), central portion (CP), and anterior horn (AH) were similarly affected (38.6%, 36.4% and 31.8%, respectively). Isolated perivascular inflammatory lesions with selective loss of astrocyte endfoot proteins, AQP4 and connexin 43, were present only in white matter and were more frequent in PC and LC than in AC (22.7%, 29.5% and 2.3%, P ^corr = 0.020, and P ^corr = 0.004, respectively). MRI indicated LESCLs more frequently affected PC and LC than AC in anti‐AQP4 antibody‐seropositive NMO/NMOSD (86.7%, 60.0% and 20.0%, P ^corr = 0.005, and P ^corr = 0.043, respectively) and AQP4 antibody‐seronegative MS patients (86.7%, 73.3% and 33.3%, P ^corr = 0.063, and P ^corr = 0.043, respectively). PH, CP and AH were involved in 93.3%, 86.7% and 73.3% of seropositive patients, respectively, and in 53.3%, 60.0% and 40.0% of seronegative patients, respectively.ConclusionsNMO frequently and extensively affects spinal white matter in addition to central gray matter, especially in PC and LC, where isolated perivascular lesions with astrocyte endfoot protein loss may emerge. Spinal white matter involvement may also appear in early NMO, similar to cerebral white matter lesions.     

GAP-43 expression in the developing rat lumbar spinal cord.

The expression of the growth-associated protein GAP-43, detected by immunocytochemistry, has been studied in the developing rat lumbar spinal cord over the period E11 (embryonic day 11), when GAP-43 first appears in the spinal cord, to P29 (postnatal day 29) by which time very little remains. Early GAP-43 expression in the fetal cord (E11-14) is restricted to dorsal root ganglia, motoneurons, dorsal and ventral roots and laterally positioned and contralateral projection neurons and axons. Most of the gray matter is free of stain. The intensity of GAP-43 staining increases markedly as axonal growth increases, allowing clear visualization of the developmental pathways taken by different groups of axons. Later in fetal life (E14-19), as these axons find their targets and new pathways begin to grow, the pattern of GAP-43 expression changes. During the period, GAP-43 staining in dorsal root ganglia, motoneurons, and dorsal and ventral roots decreases, whereas axons within the gray matter begin to express the protein and staining in white matter tracts increases. At E17-P2 there is intense GAP-43 labelling of dorsal horn neurons with axons projecting into the dorsolateral funiculus and GAP-43 is also expressed in axon collaterals growing into the gray matter from lateral and ventral white matter tracts. At E19-P2, GAP-43 is concentrated in axons of substantia gelatinosa. Overall levels decline in the postnatal period, except for late GAP-43 expression in the corticospinal tract, and by P29 only this tract remains stained.     

突触后密度蛋白-95在大鼠脊髓发育过程中的表达变化

目的:探讨突触后密度蛋白-95(PSD-95)在大鼠脊髓发育过程中的表达变化以及细胞定位。方法:采用实时定量PCR(Real-Time PCR)和Western blot测定发育不同时期PSD-95 mRNA及蛋白水平的表达变化。采用免疫荧光染色显示PSD-95在发育脊髓中的细胞定位。结果:大鼠脊髓发育过程中PSD-95 mRNA及其蛋白水平从生后1d开始逐渐升高,在生后1周达高锋,成年后维持在一定的生理水平。免疫荧光双标证实PSD-95在生后发育早期主要定位于脊髓灰质,与神经元的标记物NeuN和突触的标记物synapsin存在共定位;成年后广泛分布于脊髓前角、后角以及白质,分别与NeuN和synapsin以及小胶质细胞的标记物OX-42共定位。结论:大鼠脊髓发育过程中PSD-95在基因和蛋白水平呈现明显的时相变化,在生后发育早期主要表达在前角运动神经元和后角感觉神经元,提示PSD-95参与了神经元的发育和成熟。     

人工合成高分子支架材料治疗脊髓损伤

背景：治疗脊髓损伤的人工合成高分子支架材料是目前的研究热点之一。 目的：综述国内外人工合成高分子支架材料在治疗脊髓损伤方面的研究进展。 方法：应用计算机检索万方医学、中国知网、PubMed、EBSCO数据库中2000年1月至2012年1月关于人工合成高分子支架材料治疗脊髓损伤方面的文章,在标题和摘要中以“脊髓损伤,组织工程,人工合成高分子材料”或 “spinal cord injury,tissue engineering,synthetic polymer material”为检索词进行检索。 结果与结论：治疗脊髓损伤的人工合成高分子材料很多,主要有聚乳酸、聚羟基酸、聚β-羟丁酸、合成水凝胶、聚乙二醇及其他人工合成高分子材料。每种材料都有其优缺点,都无法达到完全的组织相容性和可降解性,这些支架材料不能完全模仿脊髓的三维多孔立体结构,移植后这些支架材料的位置相对于脊髓结构来讲是随机的,并未与脊髓的灰、白质组织学结构吻合,更没有和白质中主要纤维相对应,所以均未应用于临床。人工合成高分子支架材料在治疗脊髓损伤方面需要进一步研究。     

Quantification of microvasculature in the canine spinal cord

Capillary density and capillary orientation in canine spinal cords were estimated by calculating actual lengths, surfaces, and volumes of capillary segments in tissue sections. Transverse, sagittal, and frontal section planes were sampled from dorsal, ventral, and lateral funiculi and from dorsal and ventral gray horns of spinal segments C3, T6, and L3 from three dogs. Capillaries were defined as vessels less than 10 μm in diameter. Electron microscopy of 104 such vessels revealed no muscle coat but collagen fibrils between endothelium and astrocyte process in 68% of the white matter capillaries and 16% of those in gray matter. Capillary diameter was significantly different among regions in some cases, but consistent patterns of variation were not found. Capillary density was four to five times greater in gray matter than in white matter. Capillary density differed significantly among the same-size dogs, but within dogs, density was similar among segments and within gray matter and white matter regions. In 62% of the transverse sections, capillary orientation was significant but mean direction was variable. Significant capillary orientation was found in 89% of the sagittal and frontal sections, and the mean direction was always along the craniocaudal axis of the spinal cord. The craniocaudal orientation was significant in 96% of the white matter sections and 78% of the gray sections, and in 97% of the cervical and thoracic sections but only 73% of the lumbar sagittal and frontal sections. Because capillary orientation is neither isotropic nor regular, unbiased, lowvariance estimates of capillary density cannot be expected without resorting to excessive sampling. An efficient method of quantifying spinal capillaries for comparative purposes by counting number of profiles per unit area is recommended.