Comparison of localization of the neurokinin 1 receptor and nitric oxide synthase with calbindin D labelling in the rat spinal cord

A comparison of the localization of the neurokinin 1 (NK1) receptor and nitric oxide synthase with calbindin D labelling in the lumbar spinal cord was carried out in the rat using immunocytochemistry. Considerable regional variations were observed. Application of the antibody to calbindin D resulted in dense staining in laminae I and II and light staining in the other laminae. Occasional scattered cells were seen in the deep laminae and in the lamina X, the ventral horn and the lateral spinal nucleus. The results indicate that neurones expressing calbindin D, NK1 receptor and NOS are three separate populations in the dorsal horn of the lumbar spinal cord.     

Substance P and neurotensin are up-regulated in the lumbar spinal cord of animals with neuropathic pain

Many neuropeptides have been shown to be up-regulated in response to pain. The purpose of this study was to identify pain-related peptides in a rat model of neuropathic pain induced by sciatic nerve cuff implantation. Rats were tested for touch sensitivity prior to and 7 days following cuff implantation or sham surgeries. The lumbar spinal cord was removed on the 8th day post-surgery and the lumbar enlargement was processed for the detection of selected peptides using time-of-flight mass spectrometry. Only substance P (MW 1346.74) and neurotensin (MW 1673.0) were detected in the lumbar spinal cord of animals with mechanical allodynia (P < 0.01) following innocuous tactile stimulation of the affected hind paw. Therefore, substance P and neurotensin may be target candidates for the understanding and treatment of neuropathic pain.     

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.     

The Effects of Aortic Occlusion on Transcranially Induced Evoked Potentials in the Dog

Evoked potentials were produced by anodal stimulation over the motor cortex in six dogs. Potentials were recovered from the cranial thoracic and caudal lumbar portions of the spinal cord, and the radial and sciatic nerves. Evoked potential averages were recorded every 1.5 minutes during 40 minutes of aortic occlusion and during 40 minutes of reperfusion. Mean amplitudes of evoked potentials recovered from the caudal lumbar spinal cord decreased to 50% of original values at minute 12.2. Upon release of occlusion, the evoked potentials returned to baseline levels and remained there throughout the period of reperfusion. Sciatic nerve amplitudes decreased to 50% of original values at minute 4.5. In no subject could wave forms be recovered after minute 9.0. Upon release of occlusion, the evoked potentials returned to baseline levels and above, then deteriorated to 29 +/- 12% after 40 minutes of reperfusion. We concluded that transcranially induced evoked potentials were highly sensitive to spinal cord ischemia. Evoked potentials recovered from the sciatic nerve were consistent with functional grey matter immediately upon reperfusion, but deteriorated during reperfusion.     

神经肽Y对犊牛肝细胞PEPCKmRNA丰度及其活性的影响

取单层培养36 h生长良好的犊牛肝细胞.采用单因素重复试验,分别添加0、50、100、200、500、1 000 ng/L的羊体外合成神经肤Y(Neuropeptide Y,NPY),每个处理3个重复(每个重复2孔),再培养12 h后分别提取RNA和制备细胞上清液.应用荧光定量PCR方法检测外源NPY对肝细胞糖异生关键酶磷酸烯醇式丙酮酸羧激酶(Phosphoenolpyruvate carboxykinase,PEPCK)基因表达的影响,同时用比色法检测其对肝细胞PEPCK活性的影响.结果表明,一定浓度的NPY显著促进肝细胞PEPCK mRNA表达,增强了PEPCK活性.     

Electrical stimulation of lumbar spinal nerve roots in dogs

The aim of this study was to test the applicability of electrical stimulation of lumbar spinal nerve roots and obtain normative electrical root stimulation (ERS) data for L7 nerve root and sciatic nerve in dogs. For that purpose ERS and sciatic nerve stimulations were performed consecutively, in totally 40 healthy dogs. ERS was applied in the L7/S1 intervertebral space via monopolar needle electrodes. Muscle responses were recorded from the gastrocnemius muscles on the left and right hind limbs. Sciatic nerve stimulation was performed at the greater trochanter level on the left hind limb, with records obtained from the left gastrocnemius muscle. Mean root latencies of the left and right side were 5.22?±?0.49 ms and 5.29?±?0.53 ms, respectively. There was no significant difference in root latency between the right and left sides. The mean terminal latency was 3.82?±?0.46 ms. The proximal motor nerve conduction velocity of the sciatic nerve was 63.15?±?3.43 m/s. The results of this study show that ERS provides objective data about the integrity of lumbar spinal nerve roots by evaluating the entire population of motor fibres and total length of the motor axon in dogs. ERS can be considered a useful diagnostic method for confirmation of diagnoses of lumbosacral diseases.     

Acquired spinal cord and peripheral nerve disease.

Acquired spinal cord diseases in ruminants result most commonly from infectious, traumatic, metabolic/nutritional, or toxic causes and rarely from neoplasia. Clinical signs of spinal cord disease depend on the neuroanatomic location of the lesion. Acquired spinal cord diseases including vertebral osteomyelitis/spinal abscess, cauda-equina disease, enzootic ataxia, lymphosarcoma,polyradiculoneuritis, and degenerative myeloencephalopathy are discussed. Acquired peripheral nerve disease in cattle most often is a result of injury, and most commonly only one limb is involved.Peripheral nerve injuries frequently occur secondary to myopathy in recumbent adult cattle. In small ruminants, peripheral nerve injury seems less common, most likely due to their smaller size,but may occur from predator wounds or iatrogenically following intramuscular drug administration. Injury to the brachial plexus and radial, suprascapular, sciatic, femoral, and obturator nerves is discussed.     

北京鸭迷走背核向脊髓的直接投射——HRP法研究

采用HRP逆行追踪法,对25例北京鸭迷走背核直接投射到脊髓的传导通路的起始部位进行了研究。乌拉坦(Urethane)静脉注射麻醉动物,分别在脊髓的颈中部(C7)、颈膨大部和腰膨大部注时30～50％HRP,灌流固定,取脑做冰冻连续切片,蓝色反应显色,中性红复染,镜检。实验结果:单侧脊髓注射HRP后,在延髓的闩后部分,双侧的迷走背核内发现了标记细胞,对侧的标记细胞数量多于同侧。此外,双侧的疑核和孤束核也有一些标记细胞。在颈中部脊髓引入HRP后,出现的标记细胞较多;在颈膨大部引入HRP后,出现的标记细胞较少;在腰膨大部引入HRP后,迷走背核内不出现标记细胞,而疑核和孤束核仍有少量标记细胞。本文对禽类迷走背核和疑核至脊髓的直接传导通路,结合哺乳类的有关资料进行了讨论。     

Early embryonic development of the camel lumbar spinal cord segment

The lumbar spinal cord segment of the one-humped camel (Camelus dromedarius) embryos at 2.4- to 28-cm crown vertebral rump length (CVRL) was examined. Major changes are occurring in the organization of the lumbar spinal cord segment at this early developmental period. At first, the spinal cord is flattened from side to side but with increase in gestational age it becomes flattened dorsoventrally. The size and shape of the lumen changes in indifferent stage of development. These changes may be in relation to the decrease of ependymal layer and increase of the mantel layer during the developmental stages. The lumen of the spinal cord is a wide spindle in shape at 2.4-cm CVRL, diamond in shape at 5.5-cm CVRL and narrow oval in shape at 28-cm CVRL. It occupies about the whole, half and one-seventh of the total height of the spinal cord at 2.4-, 5.5- and 28-cm CVRL, respectively. At the 2.4-2.7 CVRL, the spinal cord is formed of six plates: roof, floor, two alar and two basal plates. The present investigation indicates that the distribution of the ependymal, mantle and marginal layers differs in the various developmental stages of the camel embryos. The majority of the cross section of the spinal cord consists at first of ependymal and mantle layers, and a thin outer rim of the marginal layer. With the advancement of age, the ependymal layer diminishes in size, while the mantle and marginal layers increase in size forming the future grey and white matters, respectively.     

Meningeal sarcoma mimicking a sciatic neuropathy in a dog

A 5-year-old Golden Retriever presented for lameness evaluation and removal of a dynamic compression plate on the left femur exhibited neurologic signs compatible with a left sciatic peripheral neuropathy. Radiographs revealed a healed fracture of the left femur and a slightly narrowed intervertebral disc space with ventral spondylosis at T_12–13. An EMG demonstrated fibrillation potentials and positive sharp waves in the left hind limb muscles innervated by the peroneal nerve. Surgery was performed to remove the bone plate and explore the left sciatic nerve. The proximal 3 cm of the left peroneal nerve was surrounded by thick fibrous connective tissue and its diameter was smaller than the more distal segment. The dog's condition remained static for 4 weeks and then gradually progressed to paraparesis in 2 weeks. A neurologic examination at that time indicated a caudal lumbar spinal cord lesion and a myelogram confirmed an intradural mass at the level of the 4th lumbar vertebra. The dog was destroyed and a necropsy performed. The histologic diagnosis was meningeal sarcoma.     

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.     

Effect of capsaicin on cholecystokinin and neuropeptide Y expressions in the brain of high-fat diet fed rats

Capsaicin, one of the pungent principles of hot pepper, has been reported to cause a cessation of increases in body weight and fat gain induced by high-fat feeding. Especially, in body weight and feeding control, cholecystokinin (CCK) has been well known as a satiety signal and neuropeptide Y (NPY) has been described as one of the most potent orexigenic signals. This study was carried out to investigate the effect of capsaicin on CCK- and NPY- immunoreactivities (IR) in the brain of high-fat fed rats. The animals were divided into normal-fat diet (NF), high-fat diet (HF) and high-fat diet containing capsaicin (HF-CAP) groups. Mean body weight gain (MBWG) of HF group was higher than that of NF group. However, in HF-CAP group, MBWG was lower than that of HF group. CCK-IR in suprachiasmatic nucleus (SCN), paraventricular nucleus (PVN), median eminence (ME), arcuate nucleus (ARC) and amygdala was not prominent in all the groups. In cerebral cortex, CCK-IR was more reduced in HF-CAP group than in the other groups. In the HF-CAP group, NPY-IR in the hypothalamic nuclei, amygdala and cerebral cortex was more poorly found than in the NF and HF groups. It is concluded that (1) NPY-IR may react more sensitively on capsaicin than CCK-IR, (2) no rapid increase of body weight in capsaicin treated rats may result from the diminished food intake through the low expression of NPY in hypothalamus in HF-CAP group.     

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.     

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.     

Effects of age and strain on the expression of leptin receptor, neuropeptide Y and pro-opiomelanocortin in the hypothalamus of young chickens

1. An experiment was conducted to study changes in the expression of the hypothalamic leptin receptor, neuropeptide Y (NPY) and proopiomelanocortin (POMC) with age during the early neonatal period in two different strains of chickens: Beijing-You (BY) and Arbor Acres (AA). 2. Compared with BY chickens, AA chickens ate more, and grew faster. Hypothalamic NPY concentrations of both strains increased with age until d 7 followed by a decline. Hypothalamic NPY of BY chickens on d 7 was lower than in AA chickens at the same age. 3. No difference with age was observed in hypothalamic α-melanocyte-stimulating hormone (α-MSH) of BY chickens, while hypothalamic α-MSH in AA chickens on d 0 was higher than on the other days. Compared with AA chickens, BY chickens showed lower hypothalamic α-MSH on d 0. 4. Similar developmental changes between two strains were observed in the expression of leptin receptor, NPY or POMC genes in the hypothalamus. Hypothalamic mRNA of leptin receptor on d 0 was higher than on d 1 and 7. Unlike NPY, hypothalamic NPY mRNA on d 0 was higher than on the other days. 5. Hypothalamic POMC mRNA decreased gradually with age until 7 d followed by a slight increase. 6. The results showed that the developmental changes of hypothalamic signal molecules varied with age and strain. NPY, α-MSH and leptin receptor might be involved in the early programming of feed intake in newly hatched chickens.     

Microglia and astrocyte activation in the spinal cord of lame horses

Objective

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

Electrophysiologic studies of the cutaneous innervation of the pelvic limb of male dogs

The area of skin supplied by the afferent fibers in one cutaneous nerve is called the cutaneous area (CA) for that nerve. The CA of peripheral branches of lumbar and sacral spinal nerves responsive to the stimulation of hair follicle mechanoreceptors were mapped in 27 dogs. The amount of overlap among the CA was similar to that found for other CA of the body. The CA of peripheral branches of the sciatic nerve were restricted to the lateral, cranial, and caudal aspects of the pelvic limb distal to the stifle. The CA of the saphenous nerve was located on the medial side of the limb, except for a small area located on the lateral side of the crus. The distal part of the CA of the saphenous nerve was completely overlapped in the hind paw by branches of the superficial peroneal nerve laterally and the medial plantar branch of the tibial nerve medially. The CA for the deep peroneal nerve was located on the dorsal surface of the webbing between digits 2 and 3 and the adjacent skin of these digits. The CA of the plantar branches of the tibial nerve were small in comparison with the diameter of the nerve, suggesting that these branches contained nerve fibers supplying other, deeper structures in the hindpaw and that damage to these nerves would interfere with cutaneous sensation in only a small region on the plantar surface of the hindpaw. Knowledge of the CA of the various branches of the sciatic nerve allows more accurate localization of injury to the sciatic nerve or its branches by using areas of anesthesia.     

神经肽Y免疫反应神经元在鸽小脑中的定位--SABC 法研究

采用石蜡切片和免疫组化SABC法（链霉亲合素-生物素-过氧化物酶连结法），对10只肉鸽小脑内神经肽Y免疫反应神经元的分布状况进行了研究．并与北京鸭、鸟鸡、肉鸡及大鼠的相关结果进行了比较。在光镜下观察分析了阳性神经元的分布状况．并用图像分析软件进行了半定量分析。结果显示：（1）小脑内神经肽Y（neuropeptide Y，NPY）阳性神经元主要存在于小脑皮质的蒲肯野氏细胞层，且以小叶顶端的蒲肯野氏细胞阳性明显；（2）小脑白质中央核可见到少量阳性神经元．不同于鸟鸡、肉鸡及大鼠；（3）分子层、颗粒层未见阳性反应细胞。表明：鸽小脑NPY阳性神经元的分布在皮质中与鸡、大鼠大体相似；在白质中与鸡、大鼠有差异。     

Distribution of a lidocaine-methylene blue solution staining in brachial plexus, lumbar plexus and sciatic nerve blocks in the dog

ObjectiveTo determine the influence on the distribution of the volume of a local anaesthetic-methylene blue solution at three different nerve block sites in the dog.Study designRandomized, controlled, blinded experimental trial.Animals23 hound-cross dogs weighing 16–40 kg and aged 2 ± 0 years (mean ± SD).MethodsDogs were anaesthetized and randomly assigned to three groups of seven or eight dogs each, based on volume administered: low, medium and high volume (L, M and H). Using electrolocation, the injection was performed after a positive response was elicited (flexion of the elbow for the brachial plexus block, quadriceps contractions for the lumbar plexus and dorsiflexion/plantar extension of the foot for the sciatic nerve block). At the brachial plexus site, groups L, M and H received 0.075, 0.15 and 0.3 mL kg⁻¹, respectively. At the lumbar plexus site, groups L, M and H received 0.1, 0.2 and 0.4 mL kg⁻¹, respectively. At the proximal sciatic nerve site, groups L, M and H received 0.05, 0.1 and 0.25 mL kg⁻¹, respectively. Necropsies were performed immediately following euthanasia. Staining of ≥2 cm along the nerve was considered sufficient; the proportions sufficient were compared with Fisher's exact test. The volume was recommended when all the relevant nerves were stained sufficiently in all or all but one of the dogs within the group.ResultsIn the brachial plexus, only in group H were all the nerves stained sufficiently. In the lumbar plexus site, no statistical difference was found, but we suggest the H group volume to balance sufficient and excessive staining. At the sciatic nerve site, all volumes tested produced sufficient staining in all (or all but one) dogs.Conclusions and clinical relevanceVolumes of 0.3 and 0.05 mL kg⁻¹ produced sufficient distribution for performing brachial plexus, and sciatic nerve blocks, respectively. Additionally, a volume of 0.4 mL kg⁻¹ might also be adequate for a lumbar plexus block (no statistical significance was reached).