Expression of neuropeptide Y and neuropeptide Y Y1 receptors and neuronal markers following axotomy in the rat spinal cord and gracile nucleus

Using immunocytochemistry, the effects of denervation on the expressions of the neuropeptide Y Y1 receptor, neuropeptide Y and neuronal markers were investigated in the lumbar spinal cord of the rat. Ten, 17 and 24 days after unilateral sciatic nerve section, the distribution of the neuropeptide Y Y1 receptor was seen in lamina II in the ipsilateral and contralateral side of the lumbar spinal cord and gracile nucleus, whereas neuropeptide Y immunoreactivity located strongly in laminae I–II and moderately in laminae III–IV in the ipsilateral side. Denervation, following section of the sciatic nerve, resulted in no change in the distribution of the neuropeptide Y Y1 receptor in the spinal cord. This suggests that the neuropeptide Y that is expressed in myelinated afferents following nerve section does not affect the expression of this receptor. This is particularly apparent in the gracile nucleus which shows clear neuropeptide Y staining following sciatic nerve section and no expression of the neuropeptide Y Y1 receptor.     

Comparison of localization of the neurokinin 1 receptor with AMPA-type glutamate receptors in the rat spinal cord

With the cloning of the alpha-amino-3-hydroxy-5-methyl-4-isaxole propionic acid (AMPA)-type receptor subunits, it is now possible to localize these receptor subunits in the spinal cord. Comparison of the neurokinin 1 receptor distribution with that of non-N-methyl-D-aspartate glutamate receptor subunits (GluR1-4), considered to be AMPA-type, was investigated in rat spinal cord by immunocytochemical methods. Different patterns of immunolabelling were observed with the antibodies to the GluR1, GluR2/3 and GluR4 subunits in the lumbar spinal cord. Immunolabelling with antibodies to both GluR1 and GluR2/3 revealed intensive staining in the dorsal horn, while staining for GluR2/3 and GluR4 was dense in the motor neurons of the ventral horn. These results suggest that in the rat spinal cord AMPA-type receptors vary their composition according to the region where they are expressed. Neurokinin-1-receptor-expressing neurons in the dorsal horn do not appear to express the GluR4 subunit, however, whether they express the GluR1, GluR2/3 receptors subunits could not be determined.     

Calbindin D-28k, parvalbumin and calcitonin gene-related peptide immunoreactivity in the canine spinal cord

This study was conducted as a comparative analysis of the immunohistochemical localization of calbindin D-28k, parvalbumin and the calcitonin gene-related peptide (CGRP) in the cervical through the sacral spinal cord of mongrel dogs, to reveal any distinct patterns of distribution and possible involvement in spinal processing. In laminae I and II of the substantia gelatinosa, both calbindin D-28k and CGRP showed strong immunoreactivity, with calbindin D-28k being positive in both cells and fibres, while CGRP was positive in fibres only. Parvalbumin and CGRP immunoreactive cells were widely distributed in various nuclei and lower motor neurones in the ventromedial horn. In addition, the lower motor neurones expressed CGRP as well as parvalbumin, but not calbindin D-28k. These results are generally consistent with previous reports, and the co-localization of parvalbumin and CGRP may explain the functional improvement of lower motor neuron disease.     

恒河猴脊髓一氧化氮合酶阳性神经元的分布

本文采用NADPH-d酶组织化学的方法，对成年恒河猴脊髓各段内一氧化氮合酶（NOS）活性进行观察。结果显示恒河猴脊髓NOS阳性神经元主要分布在中间部外侧核、中央管周围灰质、后角的Ⅲ和Ⅳ层。前角也有NOS阳性神经元分布。各部位NOS阳性神经元着色深度有所差异。NOS阳性神经纤维主要分布在后角浅层和中间带。恒河猴脊髓阳性神经元及阳性纤维的分布与人类及其它实验动物相似。     

神经生长因子及其受体TrKA在山羊脊髓发育中的表达特点

运用免疫组织化学超敏 SP法对山羊胎儿脊髓发育中神经生长因子 (nerve growth factor,NGF)及其高亲和力受体 Tr KA的表达及其功能进行了系统的研究和探讨。结果显示 ,山羊胎儿脊髓灰质中存在 NGF及其受体 Tr KA,于 6周龄胚就可检测到 ,随胚龄增加 ,其表达范围及免疫反应着色程度逐渐增强。 NGF主要分布于腹角和背角的神经细胞 ,反应产物主要定位于胞质和突起 ;Tr KA的分布主要以腹角及胶状质为主 ,反应产物主要定位于胞核 ,后期胞质及突起也可见到阳性反应。在山羊胎儿脊髓白质中也可观察到 NGF及 Tr KA免疫阳性反应 ,其发育后期更为显著 ,阳性反应主要分布于神经胶质细胞核、神经纤维的轴索及雪旺氏细胞。结果提示 ,NGF不仅对交感和感觉神经元的发育起作用 ,而且还与腹角运动神经元的发育有关     

Microtubule associated protein 2 and choline acetyltransferase immunoreactivity in the lumbar spinal cord of young adult and aged dogs

German Shepherds are a good model for research about aging and neurological disorders such as lumbosacral spinal canal stenosis. We compared neurons, glia and cholinergic neurons in the ventral horn of the lumbar spinal cord (L₃) between adult (1–2 years old) and aged (10–12 years old) groups. Any pathological findings were not found by hematoxylin and eosin staining and neurological examination, and the number of NeuN (a marker for neurons)-positive neurons were similar in both groups. Microtubule-associated protein 2 (MAP2) immunoreactive dendrites in the aged dog were decreased without any change in β-tubulin protein level. Glial fibrillary acidic protein (a marker for astrocytes) and ionized calcium-binding adapter molecule 1 (a marker for microglia) immunoreactivity were not significantly changed in both groups. The number of ChAT immunoreactive neurons was decreased; however, its protein level was not significantly changed in the aged group. These results suggest that numbers of ventral horn neurons are not changed, but cholinergic neurons may change in aged dogs compared to adult dogs.     

Spinal projections of cat primary afferent fibers innervating caudal facet joints

The spinal projections of afferent fibers innervating the facet joints between caudal vertebrae were examined by the use of anterograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP). Experiments were performed on 5 adult cats in which spinal dorsal roots below the 2nd sacral segment (S2) on the right side were cut. Injections of WGA-HRP into the caudal facet joints gave rise to extensive cranio-caudal distribution of WGA-HRP positive products along the spinal cord, indicating that many afferent fibers innervating unilateral facet joints terminate bilaterally in laminae I-II, V-VI and X of the thoracic, lumbar, sacral and caudal spinal cord. These afferent fibers may convey a series of sensory information from the caudal facet joints to the spinal cord.     

Localization of Vesicular Glutamate Transporter 2 mRNA in the Dorsal Root Ganglion of the Pigeon (Columba Livia)

Our previous study showed localization of glutamate receptor 1 (GluR1) mRNA in neurons of the pigeon spinal cord, suggesting glutamatergic input from intrinsic and extrinsic origins. The present study examined localization of vesicular glutamate transporter 2 (VGLUT2) mRNA to confirm an extrinsic origin of glutamatergic neurons in the dorsal root ganglion (DRG). GluR1 and GluR2 mRNAs were examined in DRG and spinal cord to seek projection regions from VGLUT2 mRNA‐expressing neurons. VGLUT2 mRNA was expressed in most DRG neurons and labelling intensity varied from weakly to intensely. Intense VGLUT2 mRNA expression was mainly seen in medium to large neurons. GluR1 and GluR2 mRNAs were expressed in the dorsal horn and GluR2 mRNA signal was also seen in the marginal nucleus. The results suggest that the pigeon DRG has an extrinsic glutamatergic origin that project to the dorsal horn and marginal nucleus of the spinal cord.     

Autoradiographic localisation of alpha 2 adrenoceptor binding sites in the spinal cord of the sheep

Alpha 2 adrenoceptor agonists, such as xylazine and detomidine, are used as sedatives, analgesics and premedicants. In this study the localisation of binding sites for alpha 2 agonist drugs in the sheep spinal cord was examined using [3H] clonidine as a ligand and autoradiographic techniques related to our initial histological mapping of the various tracts and laminae. The results indicated a high concentration of binding sites for alpha 2 adrenoceptor agonists in the lamina II region of the dorsal horn of the spinal cord (the substantia gelatinosa) which is an area widely implicated in the transmission of painful stimuli. Possibly therefore some of the analgesic effect of this group of drugs in sheep is mediated at the spinal level.     

The autoradiographic binding of [3H] quinuclidinyl benzilate to muscarinic receptors in the spinal cord of the sheep

Autoradiography of [3H] quinuclidinyl benzilate was used to demonstrate the distribution of muscarinic acetylcholine binding in the spinal cord of sheep. Binding was confined to the grey matter of the cord, and was most densely distributed in the substantia gelatinosa region of the dorsal horn, the lamina X region around the central canal, the intermediolateral columns and in various regions of the ventral horn. The use of specific M1 and M2 receptor subtype ligands, pirenzipine and 4-DAMP indicated that both receptor subtypes were present in most regions of dense binding.     

Possible intraspinal metastasis of a canine spinal cord nephroblastoma

A 2-year-old Basset Hound was admitted to the University of Florida Veterinary Medical Teaching Hospital with progressive spastic paraparesis. At necropsy, intradural extramedullary tumors produced areas of spinal cord swelling and softening in spinal cord segments T11-T12 and L4-L6. Histologic examination of the masses revealed sheets of polygonal blastemal cells, epithelial cells forming tubules and rosettes, and embryonal glomeruloid-like structures in the thoracic mass. Cells in the lumbar mass were less differentiated, forming rare tubules and no glomeruloid-like structures. The occurrence of two tumors in the spinal cord along with the less differentiated appearance of the lumbar tumor raises the possibility that the lumbar mass arose as a result of intraspinal metastasis. To our knowledge, this is the first report of multifocal or metastatic canine spinal nephroblastoma. In addition, the vimentin and cytokeratin immunohistochemical staining characteristics of these spinal cord nephroblastomas are described.     

Acute pelvic limb paralysis induced by a lumbar fibrocartilaginous embolism in a sow

A diagnosis of fibrocartilaginous embolism was made in a mature mixed-breed sow with a history of an acute onset of pelvic limb paralysis. Within a single section of lumbar spinal cord, there was severe focally-extensive infarction of the right ventral gray horn. Within affected white matter, there was dilatation of multiple myelin sheaths with concurrent axonal swelling. A smaller focus of infarction was present on the contralateral side. Arteries at the periphery of both lesions contained a blue-gray material with staining characteristics similar to that evidenced by the nucleus pulposus present within intervertebral discs. Grossly, no abnormalities were present within the vertebral column.     

Early Embryonic Development of the Camel Lumbar Spinal Cord Segment

The lumbar spinal cord segment of the camel embryo at CVRL 2.4 to 28 cm was examined. Major changes are occurring in the organization of the lumbar spinal cord segments during this early developmental period. At the CVRL 2.4, 2.7 and 3.6 cm the three primary layers, ependymal cells layer, mantle cells layer, marginal cells layer in the developing lumber spinal cord segment were demonstrated. The mantle layer is the first to show striking differentiation, while the marginal layer is represented by thin outer rim. Proliferation and differentiation of the neuroepithelial cells in the developing spinal cord produce the thick lateral walls, thin roof and floor plates. The spinal ganglion and dorsal root of the spinal nerve are differentiated. At 2.7 cm CVRL differential thickening of the lateral walls produces a shallow longitudinal groove called sulcus limitans , which separates the dorsal part (alar plate) from ventral part (basal plate). The ventral root of the spinal nerve, the spinal cord and ganglion are embedded in loose mesenchyme, which tends to differentiate into spinal meninges. At 3.6 cm CVRL the basal plate, which is the future ventral gray horn, seem to be quite voluminous and the dorsal and ventral roots unite to form the beginning of the spinal nerve. At 5.5 cm CVRL the alar plates enlarge forming the dorsal septum. At 8.4 cm to 10.5 cm CVRL the basal plates enlarge, and bulge ventrally on each side of the midline producing the future ventral medium fissure, and the white and gray matters can be recognized. At 28 cm CVRL the lumen of the spinal cord is differentiated into the central canal bounded dorsally and ventrally by dorsal and ventral gray commissures, and therefore the gray matter takes the appearance of a butterfly.The lumber spinal nerve and their roots are well distinguished.     

Microglia and astrocyte activation in the spinal cord of lame horses

Objective

To determine the microglial and astrocyte response to painful lameness in horses.

Study on the Developmental Changes in Angulation of Spinal Nerves, the Length of the Dorsal Roots and Spinal Nerves in Sheep

This study reports the angulation of spinal nerves, the length of dorsal roots, the length of spinal nerves and the transverse and vertical diameters of the spinal cord during pre- and postnatal life in sheep of the Mehraban breed in Iran. The spinal cord of these animals was divided into 4 regions with respect to the angulation of spinal nerves. The first region was from the first to fifth cervical and the second was from the sixth cervical to the eighth thoracic in fetuses and from the six cervical to fourth thoracic in adults. The third region was from the ninth thoracic to second lumbar in fetuses and from the fifth thoracic to second lumbar in adults, and the fourth region was from third lumbar to fourth sacral in the animals of all age groups. The length of dorsal roots from their point of emergence from the spinal cord to the dorsal root ganglia showed a direct correlation with the length of the spinal nerves. While angulation of the spinal nerves showed a converse correlation with the length of either spinal nerves or dorsal roots. The transverse diameters of the spinal cord were always longer than the vertical diameters. The greatest diameters (vertical — 7.00 mm; transverse — 10.00 mm) are recorded at C1, T1 and L6 in adult sheep.     

Stenosis of the thoracolumbar vertebral canal in a basset hound

A three-month-old female basset hound was referred to the Norwegian College of Veterinary Medicine with a history of progressive paresis of the pelvic limbs. Following neurological examination and the study of myelograms, extradural masses causing spinal cord compressions at the T₁₂.₁₃ and T₁₃-L₁ junctions were diagnosed. At necropsy bone-tissue of the vertebral laminae was found to have formed stenoses of the vertebral canal producing compressions of the spinal cord. Irreversible tissue-damage was observed in histological sections prepared from the compressed areas of the spinal cord.     

Differential expression of TAR DNA-binding protein (TDP-43) in the central nervous system of horses afflicted with equine motor neuron disease (EMND): a preliminary study of a potential pathologic marker

Equine motor neuron disease (EMND) is a neurodegenerative disorder of unknown etiology affecting horses worldwide. Trans-Active Response DNA Binding Protein of 43?kDa (TDP-43) has been reported in the central nervous system (CNS) of several neurodegenerative conditions in humans including Amyotrophic Lateral Sclerosis (ALS) and assumed to play role in the disease. We examined whether horses afflicted with EMND express the TDP-43 in CNS. Ten horses with EMND and 6 controls of different ages and breed we enrolled. Detection of presence of TDP-43 protein in the CNS was analyzed by immunohistochemical staining using rabbit anti-human TARDBP (TDP-43) polyclonal antibody. Formalin fixed neuronal tissues from medulla, cervical, and lumbar spinal cord were harvested from EMND and from control horses. Sections were assigned randomly to TDP-43 treated or rabbit anti-IgG as control. Nuclear staining of TDP-43 was detected in one of the neural tissues of 75?% of EMND-positive and 0 of 0?% of control horses in the central nervous system (medulla, and/or cervical spinal cord and/or lumbar spinal cord). TDP-43 antibody was detected in the nucleus of EMND horses and no cytoplasmic staining was noted. As in ALS, there was no pattern of age clustering associated with the detection of TDP-43. This is the first report on the staining of TDP-43 in neuronal tissues of horses and suggests that TDP-43 may play a role in the pathogenesis of EMND. Further studies are needed to elucidate the etiologic role of this protein in the diseases.     

出生前山羊颈段脊髓运动神经元的发育

应用HE染色和超薄切片技术研究第6周到出生前山羊脊髓腹角运动神经元胞体的发育变化。结果表明：1．出生前山羊脊髓腹角运动神经细胞发育包括未分化期、不成熟期、发育成熟期和成熟期4个阶段。2．发育过程中，山羊脊髓运动神经元细胞核的体积持续增长；常染色质增加，异染色质减少且趋边分布；核仁数量减少，中央核仁在第8周形成，以后逐渐发育成熟；核膜渐趋成熟。3．山羊脊髓运动神经元胞体内膜系统的发育变化的规律与神经元的发育阶段相适应。     

Arterial supply to the spinal cord of dogs and cats

The blood supply patterns to the spinal cord were examined and compared in 15 dogs and 10 cats by use of dissection and radiographic visualization. The lowest percentages of radicular contributions and the smallest diameter vessels were found in the thoracic part of the spinal cord. The central arteries were fewest in number in the thoracic region and unilaterally or bilaterally supplied the gray matter. The percentage of bilaterally distributed central arteries increased from the cervical to the lumbar regions. The anastomotic plexus on the surface of the spinal cord was found to be most dense in the cervical and lumbar regions.     

A field study of eight ovine vertebral body abscess cases

A vertebral body abscess extending into the epidural space causing spinal cord compression was diagnosed in the cervical spinal cord in four lambs and the thoracic spinal cord in four lambs. The affected lambs were aged between 4 and 10 weeks and clinical signs had been present for 7-21 days before veterinary examination. Treatment with high doses of penicillin did not result in an improvement of the neurological signs and all lambs were destroyed on humane grounds. Collection and analysis of cerebrospinal fluid (CSF) revealed a significant increase in the protein concentration in lumbar compared to cisternal CSF samples. There was a neutrophilic pleocytosis in two lumbar CSF samples. In lambs aged between 4 and 10 weeks with no history of previous locomotor dysfunction, paresis of more than 1 week duration may be suggestive of a vertebral body abscess which has extended into the epidural space causing spinal cord compression. Stagnation of CSF caudal to the lesion results in an increased protein concentration in the lumbar sample.