Structural changes in spinal cord gray matter induced by gravitational overloads

After acute exposure of rats to gravitational overloads (GO) the reactive changes in neurons and interneuronal synapses of spinal cord were found. These are interpreted as morphologic signs of increased functional activity of neurons and activation of interneuronal impulse transmission. Chronic application of GO results in both reactive changes and damage of spinal cord structures. These changes were not seen after an acute exposure to GO, and thus they are associated with the repeated GO, indicating GO cumulative effect. Administration of "Vitavis" provides a membrane-protective effect, especially in respect to mitochondria of neurons and perineuronal glial cells in cervical and thoracic segments of spinal cord. The effect was less pronounced in spinal cord lumbar segments as a result of pericapillary edema, preventing the transport or drug from capillary bed to the neural structures.     

Dendritic cells are abundant in non-lesional gray matter in multiple sclerosis

We have analyzed the localization of dendritic cells (DCs) in non-lesional gray matter (NLGM) in comparison to non-lesional white matter (NLWM) and acute or chronic active multiple sclerosis (MS) lesions. Immunohistochemistry was performed on cryostat sections for DCs markers (CD209, CD205, CD83) and other markers for inflammatory cells (CD68, CD8, CD4, CD3, CCR7, CCR5). We found cells expressing CD209 and containing myelin basic protein in both perivascular and parenchymal areas of NLGM. Our findings showing the expression of CD209(+) cells in NLGM parenchymal areas are surprising relative to the previous literature which reported the presence of CD209(+) DCs only in MS plaque perivascular areas. Although less numerous than CD209(+) cells, NLGM cells expressing mature DCs marker CD205 were consistently detected in perivascular cuffs of most lesions. In double labeling experiments, some but not all of the CD209(+) cells also expressed CD68 and CCR5. We also found CD209(+) cells in close contact with CD3(+) lymphocytes suggesting that DCs might contribute to the local activation of pathogenic T cells in the NLGM. Since injury to the NLGM is one of the key factors associated with disability accumulation, targeting DCs may represent a possible new therapeutic approach in MS to prevent disease progression.     

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。     

The morphology of extrachoroidal ependyma overlying gray and white matter in the rabbit lateral ventricle

A morphologic investigation of ependyma over gray matter (caudate nucleus) and over periventricular white matter (tapetum) of the rabbit lateral ventricle was undertaken prior to evaluation of morphological changes which occur with experimental hydrocephalus. Ependymal cells over the caudate nucleus are cuboidal and heavily ciliated. Numerous microvilli cover the cell surface. The lateral margins are straight and interdigitations between adjacent ependymal cells are absent. Ependymal cells over white matter are squamous. Nonciliated as well as ciliated cells contribute to the epithelial lining. Microvilli are present at the cell surface but tend to aggregate near the cellular borders. The lateral margins are convoluted and complex interdigitations are present between adjacent cells. Morphologic differences between ependymal cells over the caudate nucleus and those over periventricular white matter may help to explain the differential response to hydrocephalus observed in these two regions of the lateral ventricle.     

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。     

MicroRNAs in gray and white matter multiple sclerosis lesions: impact on pathophysiology

Multiple sclerosis (MS) is a chronic disease of the CNS, hallmarked by inflammation and demyelination. Early stages of the disease frequently show active lesions containing numerous foamy macrophages and inflammatory cells. Disease progression is highlighted by increasing numbers of mixed active/inactive or inactive lesions showing sparse inflammation and pronounced astrogliosis. Furthermore, gray matter lesions increase in number and extent during disease progression. MicroRNAs (miRNAs) comprise a group of several thousand (in humans more than 2000), small non-coding RNA molecules with a fundamental influence on about one-third of all protein-coding genes. Furthermore, miRNAs have been detected in body fluids, including spinal fluid, and they are assumed to participate in intercellular communications. Several studies have determined miRNA profiles from dissected white and gray matter lesions of autoptic MS patients. In this review, we summarize in detail the current knowledge of individual miRNAs in gray and white matter lesions of MS patients and present the concepts of MS tissue lesion development based on the altered miRNA profiles. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

The morphology of extrachoroidal ependyma overlying gray and white matter in the rabbit lateral ventricle.

A morphologic investigation of ependyma over gray matter (caudate nucleus) and over periventricular white matter (tapetum) of the rabbit lateral ventricle was undertaken prior to evaluation of morphological changes which occur with experimental hydrocephalus. Ependymal cells over the caudate nucleus are cuboidal and heavily ciliated. Numerous microvilli cover the cell surface. The lateral margins are straight and interdigitations between adjacent ependymal cells are absent. Ependymal cells over white matter are squamous. Nonciliated as well as ciliated cells contribute to the epithelial lining. Microvilli are present at the cell surface but tend to aggregate near the cellular borders. The lateral margins are convoluted and complex interdigitations are present between adjacent cells. Morphologic differences between ependymal cells over the caudate nucleus and those over periventricular white matter may help to explain the differential response to hydrocephalus observed in these two regions of the lateral ventricle.     

Glial reactions and degeneration of myelinated processes in spinal cord gray matter in chronic experimental autoimmune encephalomyelitis

Multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) result in inflammatory white matter lesions in the CNS. However, information is sparse with regard to the effects of autoimmune demyelinating disease on gray matter regions. Therefore, we studied the late effects of chronic EAE in C57BL/6 mice on the spinal cord gray matter using immunohistochemistry. Here, EAE induced marked astrocytic, microglial, and macrophage activation in the ventral horn gray matter, without any motoneuron loss. Activated caspase-3 was also increased in the ventral horn gray matter. Furthermore, activated poly (ADP-ribose) polymerase (PARP), another apoptotic marker, co-localized with myelin basic protein (MBP) of oligodendrocyte processes, but not with the oligodendroglial cell body marker, adenomatous polyposis coli gene clone CC1 (APC-CC1), or with neurofilament marker (RT-97) or synaptophysin of axonal arbors. However, there was no associated increase in the number of terminal deoxynucleotidyl transferase (TdT) mediated-dUTP nick end labeling positive nuclei in the spinal cord gray matter of EAE mice. In addition, co-localization of MBP and the low-affinity neurotrophin receptor, p75, was demonstrated, further supporting the notion of apoptotic oligodendrocyte process degeneration in the gray matter of EAE mice.     

嗅球成鞘细胞移植对脊髓半横断后脊髓灰质内Ca2+荧光强度的影响

目的：研究嗅球成鞘细胞(OECs)的移植对脊髓半横断后脊髓灰质细胞内游离钙离子浓度([Ca^2 ]i)的影响,探索OECs促进脊髓再生的机制。方法：将体外培养的OECs制成细胞悬浮液移植到上颈段脊髓半横断的动物模型中,用激光扫描共聚焦显微镜观察颈段脊髓厚片[Ca^2 ]i荧光强度的变化。结果：移植组与损伤组比较,损伤组损伤侧与非损伤侧[Ca^2 ]i荧光强度差异非常显著;而移植组损伤侧与非损伤侧[Ca^2 ]i荧光强度无显著差异。结论：(1)OECs对脊髓的再生有良好的促进作用;(2)OECs能够抑制[Ca^2 ]i的升高,改善损伤部位的微环境。     

Displaceable somatostatin binding sites in the gray matter and pyramidal paths of the human developing spinal cord

The binding of the somatostatin analogue, 125I-iodo-Tyr-[Tyr0,D-Trp8]S14, to the foetal (18- and 24-week-old) and infant (newborn and 17-month-old) spinal cord was examined using in vitro autoradiography. Somatostatin binding sites were detected at cervical, thoracic and lumbosacral levels in foetal as well as in infant spinal cord. The radiolabelling was localized over the grey especially in the superficial layers of the dorsal horn including the substantia gelatinosa and the marginal zone. In foetal and newborn spinal cord, the direct and crossed pyramidal paths exhibited a substantial binding of the ligand. A similar labelling was not observed in the pyramidal paths of a 17-month-old child or in anencephalic newborn spinal cord or previously described in adult. These results emphasize the early presence of somatostatin binding sites during the ontogeny of the human spinal cord. Further, the transient appearance of somatostatin binding sites in the pyramidal paths, prior the myelination, raises the question whether somatostatin receptors could be involved in the maturation of certain normal paths.     

Location of large core synaptic vesicles in the dorsal gray matter of the cat and dog spinal cord

Cross sections of aldehyde-perfused, Epon-embedded cat and dog spinal cord examined with an electron microscope display numerous synaptic vesicles with electron-opaque cores along the medial and lateral margins of the dorsal gray matter (laminae I, II, III). The cored vesicles, 750 – 1500 A in diameter are located in synaptic sacs and in small unmyelinated axons. They occur in small numbers throughout the apical gray matter but are much more numerous in a narrow band immediately adjacent to the white matter. Their numbers and location should be of value in studies on the nature and origin of this type of synaptic vesicle.     

A new pattern of spinal-cord demyelination in guinea pigs with acute experimental allergic encephalomyelitis mimicking multiple sclerosis.

A technique is described for producing large demyelinating lesions of the spinal cord in the guinea pig. Guinea pigs were pretreated by immunization with ovalbumin and water-soluble adjuvant (N-acetyl-muramyl L-alanyl D-isoglutamine, MDP) in water-in-oil emulsion (Freund''s incomplete adjuvant). They were given a large dose (10 mg) of ovalbumin i.p. one month later. After a few weeks the animals were sensitized with guinea-pig basic protein in Freund''s complete adjuvant. Five out of 11 animals developed large, distinctive, sharply demarcated, symmetrical demyelinating lesions within 30 days. These lesions occurred in the dorsal and anterior columns, root entry zones and subpial region of the spinal cord. Histology showed a considerable amount of free lipids. There were also infiltrative lesions of classical experimental allergic encephalomyelitis (EAE) of normal severity in the same animals. The demyelinating lesions resembled those seen in multiple sclerosis in their location and extent in the spinal cord and in the presence of free lipids. Control experiments indicated that pretreatment with ovalbumin/MDP and the second injection of ovalbumin was necessary for all the demyelination; moreover guinea pigs immunized with basic protein in Freund''s complete adjuvant or Freund''s incomplete adjuvant plus MDP without pretreatment only developed classical EAE with minimal or no demyelination.     

中药脊髓Ⅰ号对脊髓厚片Ca2+荧光强度的影响

目的　探讨中药脊髓Ⅰ号对脊髓厚片Ca2 + 荧光强度的影响。方法　将 33只Wistar大鼠随机分为 3组 :下胸段脊髓半横断组 (损伤组 )、对照组和中药脊髓Ⅰ号治疗组。快速处死大鼠 ,取下胸段脊髓 ,切脊髓厚片 ,用Fluo 3荧光染料孵育 ,激光共聚焦显微镜观察。结果　损伤组、对照组和中药治疗组左侧Ca2 + 荧光强度分别为 12 6 3± 3 2 7、13 34± 3 5 1和 12 89±3 31,右侧分别为 2 1 6 8± 3 6 9、14 72± 2 12和 12 97± 3 6 0 ,损伤组脊髓厚片损伤侧Ca2 + 荧光强度显著升高 ,治疗组两侧灰质Ca2 + 荧光强度无显著差异。结论　 (1)损伤侧Ca2 + 荧光强度显著升高 ;(2 )中药脊髓Ⅰ号对Ca2 + 荧光强度的升高有一定抑制作用。     

Spinal cord implantation of avulsed ventral roots in primates; correlation between restored motor function and morphology

 Functional restitution following spinal cord implantation of avulsed ventral roots was assessed electromyographically and correlated with the morphology of the regenerated neural structures in primates. The C5–C8 ventral roots were avulsed from the spinal cord in seven Macaca fascicularis monkeys. In three animals the roots were immediately reimplanted into the ventrolateral part of the spinal cord. In two monkeys the avulsed roots were reimplanted with a delay of 2 months and in two control animals the roots were not reimplanted. There was substantial recovery of function after both immediate and delayed spinal cord implantation of the avulsed ventral roots. The population of neurons that had regenerated was larger than on the control side, indicating a rescue of cells after an immediate root implantation. Different functional types of neurons had been attracted to regrow axons to the implanted root as judged by their position in the ventral horn. Thus, neurons normally supplying antagonistic muscles, such as the triceps muscle, participated in the innervation of the biceps muscle. Functionally this deficient directional specificity was correlated to both spasticity and co-contractions among agonistic and antagonistic muscles. Occasional electromyographic signs of function occurred also in control animals where the avulsed roots had not been implanted. This recovery was found to depend on regrowth from the site of avulsion, within the pia mater among the leptomeningeal cells and to the avulsed roots. The acceptable functional dexterity regained due to corrective surgery is discussed in terms of neurotrophism and plasticity. Received: 13 November 1997 / Accepted: 24 August 1998