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Introduction: Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease that results in the loss of motor neurons leading to limb paralysis and eventual death. Stem cell transplantation can be used to replenish the atrophied motor neurons and slow the progression of the disease, while the use of biomaterials, genetic engineering, and nanoparticles can reduce the hostility of the microenvironment. Thus, we propose a novel combinatorial therapeutic approach termed Amyotrophic Lateral Sclerosis Therapeutic and Regenerative (ALSTaR) cell treatment. Methods: This unified strategy will employ miRNA-124 and chitosan polyplex biomaterial to subsequently enhance engraftment of neural progenitor cells (NPCs), which will be engineered to overexpress an autophagy-regulatory gene, TFEB, and secrete an autophagy-inducing drug, trehalose. We will bioengineer an organoid model of the ventral column of the spinal cord which will be used for extensive in vitro characterization of ALSTaR cells through single-slice electrophysiology and immunocytochemistry, followed by in vivo work. Using the SOD1G93A mutant mouse model, weekly behavioural assessments of motor recovery will be conducted until the humane endpoint; thereafter extensive immunohistochemical and protein quantification analyses will be performed to determine treatment efficacy. Results: ALSTaR cell treatment should result in motor functional recovery and lifespan elongation through several cellular and molecular mechanisms, including decreased neuroinflammation, upregulation of autophagy, degradation of protein aggregates, enhancement of transplanted cell integration, and regeneration of axons. Discussion: In vitro characterization of ALSTaR cells in bioengineered spinal cord organoids will reveal stable electrophysiological recordings of motor neurons, higher levels of neuronal differentiation markers, and lower levels of inflammation markers in the ALSTaR group compared to the control group or the groups treated with just the biomaterial or just the NPCs, suggesting neuronal recovery. Behavioural assessments in the ALS mouse model will reveal increased motor coordination, neuromuscular strength, and motor activity in the ALSTaR group compared to other groups, suggesting motor functional recovery. In vivo characteriz ation of ALSTaR cells in the ALS mouse model will suggest enhanced stem cell integration and recovery of cellular and molecular processes. Conclusion: With currently no effective treatment for ALS, this novel combinatorial treatment strategy could improve the health-related quality of life of patients suffering from this debilitating disease.

BACKGROUND: Pigs and minipigs are increasingly used as non-primate large animal models for preclinical research on nervous system disorders resulting in motor dysfunction. Knowledge of the minipig pyramidal tract is therefore essential to support such models.AIM AND METHODS: This study used 5 female Göttingen minipigs aging 11-15 months. The Göttingen minipig corticospinal tract was investigated, in the same animals, with in vivo neuronal tracing and with postmortem diffusion weighted MRI tractography to provide a thorough insight in the encephalic distribution of this primary motor pathway and its decussation at the craniocervical junction.RESULTS: The two methods similarly outlined the course of the pyramidal tract from its origin in the motor cortex down through the internal capsule to the craniocervical junction, where both methods displayed an axonal crossover at the pyramid decussation. The degree of crossover was quantified with unbiased stereology, where 81-93% of the traced corticospinal fibers crossed to the contralateral spinal cord. Accordingly, in the upper cervical spinal cord the corticospinal tract is primarily distributed in the contralateral lateral funiculus and in close relation to the gray matter, wherein some direct terminations on large ventral column gray matter neurons could be identified.DISCUSSION: The combination of neuronal tracing and tractography exploited the strengths of the respective methods to gain a better understanding of the encephalic distribution and craniocervical decussation of the Göttingen minipig corticospinal tract. Moreover, a quantification of the crossing fibers was obtained from the tracing data, which was not possible with tractography. Our data indicate that the porcine corticospinal system is quite lateralized down to the investigated upper cervical levels. However, further elucidation of this point will require a full examination of the corticospinal tracing pattern into the caudal spinal cord combined with an analysis of the direct versus indirect termination pattern on the lower motor neurons.

Thoracic myelopathy is often caused by vertebral body fractures resulting from neoplastic conditions, traumatic events, or infectious diseases. One of the preferred procedures for treating it is the lateral extracavitary approach (LECA) with single-level or multilevel decompressive corpectomy and reconstruction. The aim of this retrospective study was to analyze the thoracic lateral extracavitary approach with corpectomy using vertebral body replacement systems (VBR-S) and dorsal reconstruction. Twenty-four patients with metastatic or primary lesions of thoracic vertebrae T2–T12 underwent spinal decompression and ventral column reconstruction with correction of spinal deformity via a LECA. One-level to four-level corpectomies were performed with additional navigated dorsal pedicle screw fixation at an average of two levels above and below the corpectomy lesion. None of the patients received preoperative spinal embolization, and the majority of the patients were admitted to radiotherapy postoperatively. Their mean age was 56 years (± 15), with a female-to-male sex ratio of 8 to 16. Patients with a minimum follow-up period of 16 months were included. The Karnofsky index, preoperative and postoperative numeric rating scale (NRS), and Frankel scale were measured. In addition, intraoperative loss of blood (LOB), units of packed red blood cell (PRBC) transfusions, the duration of the operation, and the hospitalization period were evaluated and correlated with preoperative and postoperative values. The majority of the patients were suffering from metastatic lesions and were treated with a 1 level corpectomy (median 1 level, range 1 to 4). The mean duration of surgery was 288 min (± 121) and the mean LOB was 1626 mL (± 1486 mL), with approximately two PRBC units per patient used. All patients were transferred to the intensive care unit (ICU) postoperatively, with a mean ICU stay of 2.0 days (± 1 day). The mean hospitalization period was 13 days (± 7 days). No implant-related failures or procedure-related deaths were observed. Significant differences were noted between the preoperative and postoperative Karnofsky index (74 vs. 84%) and NRS (4 vs. 2). One patient required revision surgery due to a superficial wound infection, and another needed revision surgery due to a dural tear. In another patient, an iatrogenic dural tear was repaired during the same surgical procedure and did not lead to postoperative complications. Four pleural effusions and one pneumothorax were observed, so that the overall complication rate was approximately 33%. Four of the patients died within 2 years of the operation due to progression of the primary disease. Lateral corpectomy and sagittal reconstruction of the thoracic spine using VBR-S conducted via a navigated LECA approach yields favorable results, despite the burden of neoplastic disease. These challenging procedures are accompanied by increased LOB and hospitalization periods, with moderate transfusion requirements. Surgery-related complications are low and local tumor control is satisfactory, despite the progression of the underlying neoplastic disease. However, optimal surgical therapy does not ensure long-term survival. Study design Retrospective analysis of thoracic corpectomies Level of evidence 4

The spinal cord is a vital link between the brain and the body and mainly comprises neurons, glial cells and nerve fibres. In this work, nonlinear optical (NLO) microscopy based on intrinsic tissue properties was employed to label-freely analyze the cells and matrix in spinal cords at a molecular level. The high-resolution and high-contrast NLO images of unstained spinal cords demonstrate that NLO microscopy has the ability to show the microstructure of white and grey matter including ventral horn, intermediate area, dorsal horns, ventral column, lateral column and dorsal column. Neurons with various sizes were identified in grey matter by dark spots of nonfluorescent nuclei encircled by cytoplasm-emitting two-photon excited fluorescence signals. Nerve fibres and neuroglias were observed in white matter. Besides, the spinal arteries were clearly presented by NLO microscopy. Using spectral and morphological information, this technique was proved to be an effective tool for label-freely imaging spinal cord tissues, based on endogenous signals in biological tissue. With future development, we foresee promising applications of the NLO technique for in vivo, real-time assessment of spinal cord diseases or injures.

Surgical treatment of 177 patients with monolocal fractures of thoracic and lumbar vertebral bodies was performed using transpedicular fixation (n=17), transpedicular fixation and osteoplasty (n=101), vertebroplasty (n=48) or kyphoplasty (n=ll). Restoration of support ability of the fractured osteoporotic vertebrae within ventral column by means of plasty particularly in combination with internal fixation allows achievement of better clinical outcomes, improvement of the quality of life in patients in the early and late periods after surgery.

In Arabidopsis thaliana, the E-class SEPALLATA (SEP) genes are generally expressed across all floral whorls. These genes play fundamental roles in floral organ fate determination during development by interacting with other MADS-box gene products, such as those from A-, B-, and C-class genes. However, the function of SEP genes in orchid remains obscure. Here, we analyzed a mutant orchid cultivar with greenish flowers in Habenaria radiata and found that this phenotype is caused by the absence of SEP function. Wild type H. radiata flowers contain a column and two perianth whorls consisting of three greenish sepals, two white petals, and a lip (labellum). By contrast, the flowers of H. radiata cultivar ‘Ryokusei’ appear greenish, with three normal sepals in whorl 1, two greenish petals and a lip in whorl 2, and several sepaloid organs and a ventral column in whorls 3 and 4. We isolated two SEP-like genes (HrSEP-1 and HrSEP-2) and two AGAMOUS-like genes (HrAG-1 and HrAG-2) from wild type H. radiata and compared their expression in the wild type vs. the mutant cultivar. HrAG-1 and HrAG-2 were expressed in the column in the wild type, whereas these genes were expressed in the ventral column and in sepaloid organs that had been converted from a column in ‘Ryokusei.’ HrSEP-1 and HrSEP-2 were expressed in all floral organs in the wild type. However, in the mutant cultivar, HrSEP-2 was expressed in all floral organs, while HrSEP-1 expression was not detected. Thus, we analyzed the genomic structures of HrSEP-1 in the wild type and ‘Ryokusei’ and identified a retrotransposon-like element in its first exon in ‘Ryokusei.’ Yeast two-hybrid assays demonstrated that HrSEP-1 interacts with HrDEF, HrAG-1, and HrAG-2. These results indicate that the mutant phenotype of ‘Ryokusei’ flowers is caused by the loss of function of HrSEP-1. Therefore, this gene plays an important role in column, lip, and petal development in H. radiata flowers.

The purpose of this study was to assess the pathological variation in white matter tracts in the adult severe thoracic contusion spinal cord injury (SCI) rat models combined with in vivo magnetic resonance imaging (MRI), as well as the effect of spared white matter (WM) quantity on hindlimb motor function recovery. 7.0T MRI was conducted for all experimental animals before SCI and 1, 3, 7, and 14 days after SCI. The variation in the white matter tract in different regions of the spinal cord after SCI was examined by luxol fast blue (LFB) staining, NF200 immunochemistry, and diffusion tensor imaging (DTI) parameters, including fraction anisotropy, mean diffusivity, axial diffusion, and radial diffusivity. Meanwhile, Basso-Beattie-Bresnahan (BBB) open-field scoring was performed to evaluate the behavior of the paraplegic hind limbs. The quantitative analysis showed that spared white matter measures assessed by LFB and MRI had a close correlation (R2 = 0.8508). The percentage of spared white matter area was closely correlated with BBB score (R2 = 0.8460). After SCI, spared white matter in the spinal cord, especially the ventral column WM, played a critical role in motor function restoration. The results suggest that the first three days provides a key time window for SCI protection and treatment; spared white matter, especially in the ventral column, plays a key role in motor function recovery in rats. Additionally, DTI may be an important noninvasive technique to diagnose acute SCI degree as well as a tool to evaluate functional prognosis. During the transition from nerve protection toward clinical treatment after SCI, in vivo DTI may serve as an emerging noninvasive technique to diagnose acute SCI degree and predict the degree of spontaneous functional recovery after SCI.

The purpose of this retrospective analyses was to evaluate the bone viability in the ventral column of the spine following large segmental defect reconstructions. Osseous integration of implants following spinal fusion procedures is an essential precondition to provide adequate mechanical strength to any applied forces and subsequently satisfying patient outcomes. Although CT scan is the non-invasive gold standard for fusion assessment, it lacks the ability to visualize bone viability and, therefore, discrepancy remains about sensitivity and specificity of CT as evaluation tool of spinal fusion.A novel modality, (18)F Fluoride PET/CT, specifically allows quantitative in vivo evaluation of metabolic activity of the osseous integration. Bone viability following large segmental reconstructions in patients after mono- and multi-level en bloc spondylectomies (EBS) was analyzed. Spinal fusion was assessed on plain radiographs and CT scans according to the FDA fusion criteria as well as (18)F PET/CT.A total of eight patients underwent (18)F PET/CT were included (one 4-level-, one 3-level, two 2-level and four 1-level EBS). The average follow-up between EBS and radiographic studies was 24.8 months. On plain radiographs and CT scans, successful fusion was confirmed in all patients. However, (18)F PET/CT showed non-union in all cases. The metabolic bone activity within the cage was fourfold decreased compared to the reference vertebra, whereas the metabolic activity of the adjacent endplates was 1.6-fold increased compared to the reference vertebra.This study suggests a discrepancy between fusion rates assessed by plain radiographs and CT scan compared to (18)F PET/CT.

Lack of normal reference value of diffusion tensor imaging parameters hinders its application in clinical practice. In this study, we aim to establish a comprehensive normal DTI database of Chinese subjects. Sixty-five healthy subjects aged 21–61 years were recruited and underwent 3T DTI scan of cervical spine. DTI parameters were measured in whole cord, ventral, lateral and dorsal column from C2 to C7 segments. Regions, segments, gender and age-related changes of DTI parameters were analyzed. No significant difference was found between genders (p > 0.05). DTI parameters significantly differed among different cord levels (p

Motor neurons differentiate from a ventral column of progenitors and settle in static clusters, the motor nuclei, next to the floor plate. Within these cell clusters, motor neurons receive afferent input and project their axons out to muscle targets. The molecular mechanisms that position motor neurons in the neural tube remain poorly understood. The floor plate produces several types of guidance cues with well-known roles in attracting and repelling axons, including the Slit family of chemorepellents via their Robo receptors, and Netrin1 via its DCC attractive receptor. In the present study we found that Islet1(+) motor neuron cell bodies invaded the floor plate of Robo1/2 double mutant mouse embryos or Slit1/2/3 triple mutants. Misplaced neurons were born in their normal progenitor column, but then migrated tangentially into the ventral midline. Robo1 and 2 receptor expression in motor neurons was confirmed by reporter gene staining and anti-Robo antibody labeling. Mis-positioned motor neurons projected their axons longitudinally within the floor plate, and failed to reach their normal exit points. To test for potential counteracting ventral attractive signals, we examined Netrin-1 and DCC mutants, and found that motor neurons shifted dorsally in the hindbrain and spinal cord, suggesting that Netrin-1/DCC signaling normally attracts motor neurons closer to the floor plate. Our results show that motor neurons are actively migrating cells, and are normally trapped in a static position by Slit/Robo repulsion and Netrin-1/DCC attraction.

This retrospective study investigated the early results of a single-stage posterolateral transpedicular corpectomy and fusion in the thoracolumbar spine. A modified technique with nerve preservation and bilateral expandable cage implantation is described. Four patients with vertebral metastasis and one patient with vertebral osteomyelitis were included in this series. Two patients underwent two level corpectomies, whereas three patients underwent single level corpectomy. The mean follow-up was 3.3 months. No perioperative complication was encountered. Improvement in neurological status was observed in patients with preoperative neurological deficits. Vertebral height and sagittal and coronal deformity were corrected using the current technique. Bilateral cage implantation offers an additional advantage of asymmetrical reconstruction of the ventral column in cases of hemicorpectomy. Single-stage posterolateral transpedicular corpectomy and fusion is a useful approach to treat ventral thoracolumbar pathologies.

Ethidium bromide (EB) has been extensively used in the rat as a model of spinal cord demyelination. However, this lesion has not been addressed in the adult mouse, a model with unlimited genetic potential. Here we characterize behavioral function, inflammation, myelin status and axonal viability following bilateral injection of 0.20 mg/mL ethidium bromide or saline into the ventral white matter (VWM) of female C57Bl/6 mice. EB-induced VWM demyelination significantly reduced spared VWM and Basso Mouse Scale (BMS) scores persisting out to 2 months. Chronic hindlimb dysfunction was accompanied by a persistent inflammatory response (demonstrated by CD45(+) immunofluorescence) and axonal loss (demonstrated by NF-M immunofluorescence and electron microscopy; EM). These cellular responses differ from the rat where inflammation resolves by 3-4 weeks and axon loss is minimal following EB demyelination. As these data suggest that EB-injection in the mouse spinal cord is a non-remyelinating lesion, we sought to ask whether wheel running could promote recovery by enhancing plasticity of local lumbar circuitry independent of remyelination. This did not occur as BMS and Treadscan assessment revealed no significant effect of wheel running on recovery. However, this study defines the importance of descending ventral motor pathways to locomotor function in the mouse as VWM loss results in a chronic hindlimb deficit.

It is widely accepted that the immune system plays important functional roles in regeneration after injury to the spinal cord. Immune response towards injury involves a complex interplay of immune system cells, such as neutrophils, macrophages and microglia, T- and B-lymphocytes. We investigated the influence of the lymphocyte component of the immune system on the locomotor outcome of severe spinal cord injury in a genetic mouse model of immune suppression. Transgenic mice lacking mature T- and B-lymphocytes due to the recombination activating gene 2 gene deletion (RAG2-/- mice) were subjected to severe compression of the lower thoracic spinal cord, with the wild-type mice of the same inbred background serving as controls. According to both the Basso Mouse Scale score and single frame motion analysis, the RAG2-/- mice showed improved recovery in comparison to control mice at six weeks after injury. Better locomotor function was associated with enhanced catecholaminergic and cholinergic reinnervation of the spinal cord caudal to injury and increased axonal regrowth/sprouting at the site of injury. Myelination of axons in the ventral column measured as g-ratio was more extensive in RAG2-/- than in control mice 6weeks after injury. Additionally, the number of microglia/macrophages was decreased in the lumbar spinal cord of RAG2-/- mice after injury, whereas the number of astrocytes was increased compared with controls. We conclude that T- and B-lymphocytes restrict functional recovery from spinal cord injury by increasing numbers of microglia/macrophages as well as decreasing axonal sprouting and myelination.

Here, we describe a bilateral cervical contusion model for mice. Adult female mice received graded bilateral contusion injuries at cervical level 5 (C5) using a commercially available impactor (the IH device). Three separate experiments were carried out to define conditions that produce impairments in forelimb function without unacceptable impairment of general health. A grip strength meter (GSM) was used to assess gripping ability as a measure of forelimb motor function; lesion size was assessed histologically by staining cross sections for HE and GFAP. In Experiment 1, mice received injuries of 30 kilodynes (kdyn); these produced minimal deficits on grip strength. In Experiment 2, mice received injuries of 75 kdyn and 100 kdyn. Injuries of 75 kdyn produced transient deficits in gripping that recovered between 3 and 15 days post-injury (dpi) to about 90% of control; injuries of 100 kdyn produced deficits that recovered to about 50% of control. In Experiment 3, none of the mice that received injuries of 100 kdyn recovered gripping ability. Histological assessment revealed graded injuries that ranged from damage limited primarily to the dorsal column (DC) to damage to the DC, grey matter, ventral column and lateral column. Most lesions filled in with a fibrous tissue matrix, but fluid-filled cystic cavities were found in 13% of the 100 kdyn injury group and a combination of fibrous-filled/fluid-filled cystic cavities were found in 22% and 38% of the 75-kdyn and 100-kdyn injury groups, respectively. There was minimal urine retention following cervical contusion injuries indicating preservation of bladder function. Our results define conditions to produce graded bilateral cervical contusion injuries in mice and demonstrate the usefulness of the GSM for assessing forelimb motor function after cervical contusions.

Studies that have assessed regeneration of corticospinal tract (CST) axons in mice after genetic modifications or other treatments have tacitly assumed that there is little if any regeneration of CST axons in normal mice in the absence of some intervention. Here, we document a previously unrecognized capability for regenerative growth of CST axons in normal mice that involves growth past the lesion via the ventral column. Mice received dorsal hemisection injuries at thoracic level 6-7, which completely transect descending CST axons in the dorsal and dorsolateral column. Corticospinal projections were traced by injecting biotinylated dextran amine (BDA) into the sensorimotor cortex of one hemisphere either at the time of the injury or 4 weeks after injury, and mice were killed at 20-23 or 46 d after injury. At 20-23 d after injury, BDA-labeled CST axons did not extend past the lesion except in one animal. By 46 d after injury, however, a novel population of BDA-labeled CST axons could be seen extending from the gray matter rostral to the injury into the ventral column, past the lesion, and then back into the gray matter caudal to the injury in which they formed elaborate terminal arbors. The number of axons with this highly unusual trajectory was small ( approximately 1% of the total number of labeled CST axons rostral to the injury). The BDA-labeled axons in the ventral column were on the same side as the main tract and thus are not spared ventral CST axons (which would be contralateral to the main tract). These results indicate that normal mice have a capacity for CST regeneration that has not been appreciated previously, which has important implications in studying the effect of genetic or pharmacological manipulations on CST regeneration in mice.

In this study, double immunofluorescence methods were used to investigate possible colocalization of the neurotransmitters dopamine [DA] and GABA in rostral spinal cord neurones in the upstream migrating adult sea lamprey (Petromyzon marinus). Double immunofluorescence revealed that all the DA-immunoreactive (ir) cerebrospinal fluid-contacting (CSF-c) cells, approximately 30% of the medioventral DA-ir cells, and most of the DA-ir cells located in the grey lateral to the central canal were also GABA-ir. The results also revealed some DA-ir cells located dorsally to the central canal, which increases the number of dopaminergic cell types known in lamprey. Double-labelled fibres were mainly distributed in the ventral column, and double-labelled boutons contacted some dorsal GABA-ir CSF-c cells, as well as some non-CSF-c GABA-ir cells and ventromedial dendrites of motoneurones. The findings reveal colocalization of dopamine and GABA in some cells and fibres, which suggests co-release of these substances in some synaptic terminals. Although dopaminergic/GABAergic CSF-c cells have been reported in some other vertebrates, the other double-labelled spinal populations appear exclusive to lampreys.

Freezing defined as the complete absence of body movements is a normal response of animals to unavoidable fear stimuli. The present review presents a series of evidence relating different defensive patterns with specific anxiety disorders. There are at least four different kinds of freezing with specific neural substrates. The immobility induced by stimulation of the ventral column of the periaqueductal gray (vPAG) has been considered a quiescence characteristic of the recovery component of defense-recuperative processes. There is an isomorphism between freezing response to contextual stimuli paired with electrical shocks and generalized anxiety disorder. Besides, two types of freezing emerge with the electrical stimulation of the dorsal aspects of the periaqueductal gray (dPAG): the dPAG-evoked freezing and the dPAG post-stimulation freezing. Evidence is presented in support of the hypothesis that whereas dPAG-evoked freezing would serve as a model of panic attacks, the dPAG post-stimulation freezing appears to be a model of panic disorder. It is also proposed that conditioned freezing plus dPAG electrical stimulation might also mimic panic disorder with agoraphobia. A model of serotoninergic modulation through on- and off-cells of the defense reaction generated in the dPAG is also presented. The understanding of how the periaqueductal gray generates and elaborates different types of freezing is of relevance for our better knowledge of distinct types of anxiety such as panic disorder or generalized anxiety disorder.

This study was undertaken as part of the NIH “Facilities of Research-Spinal Cord Injury” project to support independent replication of published studies. Here, we repeated a study reporting that treatment with the NgR antagonist peptide NEP1-40 results in enhanced growth of corticospinal and serotonergic axons and enhanced locomotor recovery after thoracic spinal cord injury. Mice received dorsal hemisection injuries at T8 and then received either NEP1-40, Vehicle, or a Control Peptide beginning 4–5 hours (early treatment) or 7 days (delayed treatment) post-injury. CST axons were traced by injecting BDA into the sensorimotor cortex. Serotonergic axons were assessed by immunocytochemistry. Hindlimb motor function was assessed using the BBB and BMS scales, kinematic and footprint analyses, and a grid climbing task. There were no significant differences between groups in the density of CST axon arbors in the gray matter rostral to the injury or in the density of serotonergic axons caudal to the injury. Tract tracing revealed that a small number of CST axons extended past the lesion in the ventral column in some mice in all treatment groups. The proportion of mice with such axons was higher in the NEP1-40 groups that received early treatment. In one experiment, mice treated with either NEP1-40 or a Control Peptide (reverse sequence) had higher BBB and BMS scores than Vehicle-treated controls at the early post-injury testing intervals, but scores converged at later intervals. There were no statistically significant differences between groups on other functional outcome measures. In a second experiment comparing NEP-treated and Vehicle controls, there were no statistically significant differences on any of the functional outcome measures. Together, our results suggest that treatment with NEP1-40 created a situation that was slightly more conducive to axon regeneration or sprouting. Enhanced functional recovery was not seen consistently with the different functional assessments, however.

OBJECTIVE To evaluate the techniques of minimally invasive single- and multilevel corpectomy and reconstruction of the thoracic and thoracolumbar spine using expandable vertebral body replacement (VBR) cages and ventrolateral plate fixation (VPF) via anterolateral retropleural (ALRA) and combined thoracoabdominal approaches. METHODS 38 patients with spondylitis, traumatic or metastatic lesions of thoracic or thoracolumbar vertebrae T4 to L2 underwent spinal decompression and ventral column reconstruction with correction of spinal deformity by VBR and VPF via ALRA or a combined lateral extrapleural/extraperitoneal (extracoelomic) thoracolumbar approach (CLETA). Overall clinical and neurological outcome, operative time, blood loss, reduction of deformity, and postoperative pain were assessed during a mean follow-up period of 22.8 months. RESULTS VBR and VPF were carried out successfully without conversion to conventional approaches in all patients. Mean operative time (ALRA, 163 +/- 33 min; CLETA, 175 +/- 39 min), mean blood loss (ALRA, 280 +/- 160 ml; CLETA, 420 +/- 250 ml), average correction (19.3 degrees), loss of correction of sagittal deformity (0.9 degrees), and clinical outcome compare favorably to the results reported for open and endoscopic techniques. Postoperative pain levels (mean visual analog scale score at 24 h, 2.7 +/- 0.9) and the incidence of postoperative pulmonary dysfunction (three out of 38 patients) were low. The average length of stay was 7.4 days. ALRA and CLETA obviate routine chest tube insertion, thus allowing for early postoperative ambulation (average, 1.1 d). CONCLUSION Minimally invasive VBR and VPF conducted via minimally invasive approaches (ALRA or CLETA) yields favorable clinical results at least equal to conventional open surgery, with significant reductions in perioperative morbidity and pain, expedited ambulation, and early discharge from the hospital.

Metastatic epidural spinal cord compression (MESCC) often requires anterior–posterior decompression and stabilization. To reduce approach-related complications, single-stage posterolateral vertebrectomy and 360° fusion is often performed. However, a sufficient reduction of kyphotic deformity through this approach has not been reported. The purpose of this study is to investigate the efficacy of kyphotic deformity reduction by this approach in MESCC. A retrospective analysis and chart review was performed for 14 consecutive patients who underwent a vertebrectomy and decompression from a posterolateral approach. Anterior mesh stabilization of the ventral column is used as hypomochlion for the posterior compression manoeuvre, which leads to reduction of the kyphotic deformity. Pre-operative back pain was 7.2 on a visual analogue scale. Back pain was reduced to 4.4 at discharge and 2.0 at the latest follow-up with a mean follow-up of 12 months (p

Cervical myelopathy results in loss of nerves functions along the spinal cord below the damage area as it is the result of spinal cord compression which nowadays always occur during traffic accidents. Patients with cervical myelopathy do not necessarily share the same symptoms. These vary according to the degree of cervical cord compression and cross sectional shape at every segment of cervical cord which caused difficulties in diagnosis. In this study, two dimension model of every cervical cord segment were built. Then, differences of compression results in every segment were verified. After that, to verify the effects of compression to other segments, three dimensions model of cervical cord model is built. From this study, we can see that cervical cord with flat shaped gray matter have higher stress distribution than cervical cord with hill shaped grey matter. Other than that, the injury start occurred in ventral column of white matter instead of gray matter during early injury stage.

Thoracolumbar vertebral fractures are not only characterized by frequent osteoligamentous instability, but also often by irreversible damage to to the intervertebral disk. Treatment guidelines can be formulated based on an accurate classification system. In addition to reconstructing the axis of rotation, it is crucial that the width of the spinal canal be restored when neurological deficits are present. Both indirect dorsal compression and ventral endoscopically guided direct decompression are equally of decisive importance. To achieve long-term stability with as little corrective loss as possible, the ventral column absorbing pressure is surgically stabilized by diligently resecting a destroyed intervertebral disk and vertebral fragments and replacing it with a corticocancellous bone graft or cage. The goal should always be to keep the fusion length as short as possible.

Nitric oxide synthase (NOS) activity was studied in the gray and white matter regions of the spinal cord 2 and 5 days after multiple cauda equina constrictions of the central processes of L7-Co5 dorsal root ganglia neurons. The results show considerable differences in enzyme activity in the thoracic, upper lumbar, lower lumbar, and sacral segments. Increased NOS activity was observed at 2 days after multiple cauda equina constrictions in the dorsal, lateral, and ventral columns of the lower lumbar segments and in the ventral column of the upper lumbar segments. The values returned to control levels within 5 postconstriction days. In the lateral columns of thoracic segments taken 2 and 5 days after surgery, NOS activity was enhanced by 54% and 55% and in the upper lumbar segments by 130% and 163%, respectively. Multiple cauda equina constrictions performed surgically for 2 and 5 days caused a significant increase in NOS activity predominantly in the gray matter regions of thoracic segments. A quite different response was found 5 days postconstriction in the upper lumbar segments, where the enzyme activity was significantly decreased in the dorsal horn, intermediate zone, and ventral horn. No such extreme differences could be seen in the lower lumbar segments, where NOS activity was significantly enhanced only in the ventral horn. The data correspond with a higher number of NOS immunoreactive somata, quantitatively evaluated in the ventral horn of the lower lumbar segments at 5 days after multiple cauda equina constrictions. While the great region-dependent heterogeneity in NOS activity seen 2 and 5 days after multiple cauda equina constrictions is quite apparent and suggestive of an active role played by nitric oxide in neuroprotective or neurotoxic processes occurring in the gray and white matter of the spinal cord, the extent of damage or the degree of neuroprotection caused by nitric oxide in compartmentalized gray and white matter in this experimental paradigm would be possible only using longer postconstriction periods.

The funicular distribution of nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd)-exhibiting axons was examined in the white matter of the rabbit spinal cord by using horizontal, parasaggital, and transverse sections. Four morphologically distinct kinds of NADPHd-exhibiting axons (2.5–3.5 μm in diameter) were identified in the sulcomarginal fasciculus as a part of the ventral column in the cervical and upper thoracic segments and in the long propriospinal bundle of the ventral column in Th3–L3 segments. Varicose NADPHd-exhibiting axons of the sympathetic preganglionic neurons, characterized by widely spaced varicosities, were found in the ventral column of Th2–L3 segments. A third kind of NADPHd-positive ultrafine axons, 0.3–0.5 μm in diameter with numerous varicosities mostly spherical in shape, was identified in large number within Lissauer's tract. The last group of NADPHd-exhibiting axons (1.0–1.5 μm in diameter) occurred in the Lissauer tract. Most of these axons were traceable for considerable distances and generated varicosities varying in shape from spherical to elliptical forms. The majority of NADPHd-exhibiting axons identified in the cuneate and gracile fascicles were concentrated in the deep portion of the dorsal column. An extremely reduced number of NADPHd-exhibiting axons, confirmed by a computer-assisted image-processing system, was found in the dorsal half of the gracile fascicle. Axonal NADPHd positivity could not be detected in a wide area of the lateral column consistent with the location of the dorsal spinocerebellar tract. Numerous, mostly thin NADPHd-positive axonal profiles were detected in the dorsolateral funiculus in all the segments studied and in a juxtagriseal portion of the lateral column as far as the cervical and lumbar enlargements. A massive occurrence of axonal NADPHd positivity was detected in the juxtagriseal layer of the ventral column all along the rostrocaudal axis of the spinal cord. The prominent NADPHd-exhibiting bundles containing thick, smooth, nonvaricose axons were identified in the mediobasal and central portion of the ventral column. First, the sulcomarginal fasciculus was found in the basal and medial portion of the ventral column in all cervical and upper thoracic segments. Second, more caudally, a long propriospinal bundle displaying prominent NADPHd positivity was localized in the central portion of the ventral column throughout the Th3–L3 segments.

Previous investigations from our laboratory have documented that the neuropil of the phrenic nucleus contains a dense accumulation of punctate nicotinamide adenine dinucleotide phosphate diaphorase staining. In this study we investigated the occurrence and origin of punctate nitric oxide synthase immunoreactivity in the neuropil of the phrenic nucleus in C3–C5 segments, supposed to be the terminal field of the premotor bulbospinal respiratory nitric oxide synthase-immunoreactive pathway in the dog. As the first step, nitric oxide synthase immunohistochemistry was used to characterize nitric oxide synthase-immunoreactive staining of the phrenic nucleus and nitric oxide synthase-containing neurons in the dorsal and rostral ventral respiratory group and in the Botzinger complex of the medulla. Dense punctate nitric oxide synthase immunoreactivity was found on control sections in the neuropil of the phrenic nucleus. Several thin bundles of nitric oxide synthase-immunoreactive fibers were found to enter the phrenic nucleus from the lateral and ventral column. Nitric oxide synthase-containing neurons were revealed in the dorsal respiratory group of medulla corresponding to the ventrolateral nucleus of the solitary tract and in the rostral ventral respiratory group beginning approximately 1 mm caudal to the obex and reaching to 650 μm rostral to the obex. Axotomy-induced retrograde changes, consisting in a strong upregulation of nitric oxide synthase-containing neurons, were found in the dorsal and rostral ventral respiratory group contralateral to the hemisection performed at the C2–C3 level. Concurrently, a strong depletion of the punctate nitric oxide synthase immunopositivity in the neuropil of the phrenic nucleus ipsilaterally with the hemisection was detected, thus revealing that a crossed premotor bulbospinal respiratory pathway contains a fairly high number of nitric oxide synthase-immunopositive fibers terminating in the phrenic nucleus. The use of the retrograde fluorescent tracer Fluorogold injected into the phrenic nucleus and an analysis of sections cut through the dorsal and rostral ventral respiratory group and Botzinger complex of medulla and processed for nitric oxide synthase immunocytochemistry revealed that approximately 73.8% of crossed premotor bulbospinal respiratory nitric oxide synthase-immunoreactive axons originate in the rostral ventral respiratory group and 26.2% is given by nitric oxide synthase-containing neurons of the dorsal respiratory group. A few premotor nitric oxide synthase-immunoreactive axons originating from the Botzinger complex were found. In summary, the present study provides evidence for a hitherto unknown premotor bulbospinal respiratory nitric oxide synthase-immunoreactive pathway connecting the bulbar respiratory centers with the motor neurons of the phrenic nucleus in the dog.

Some 30% of unstable vertebral fractures of the thoracic and lumbar spine involve a destruction of the ventral column and thus of the supporting structures of the spine. This requires extensive surgical reconstruction procedures, which are carried out using minimally invasive techniques. The disadvantages of the minimally invasive methods are the high cost, the technical equipment and the expenditure of time required in the initial phase for the performance of the surgical procedure. With the structural reform of the health care system in the year 2000, the private-sector regulatory bodies were called upon to introduce a flat-rate compensation system for hospital services according to section 17b of the Hospital Law (KHG). The previous financing system which involved per-diem operating cost rates has thus been abolished. Calculations of individual entities are now required. Considering the case values to date, a contribution margin deficit of EUR 4628.45 has been calculated for our patients with fractures of the thoracic and lumbar spine without neurological defunctionalization symptoms. An economically efficient medical care is thus no longer possible. Consequently, an adjustment of the German relative weights must urgently be demanded in order to guarantee a high-quality medical care of patients.

Communication and interaction between cells has been shown to be important during the embryonic development of the vertebrate hindbrain, which becomes transiently subdivided into segments called rhombomeres (r). One gene family allowing intercellular communication and possibly being involved in the control of hindbrain development is the connexin family encoding gap junction channels. Here, we have characterized in detail the previously observed (Dahl et al., 1997) expression of one particular connexin gene, connexin31 (Cx31), in the mouse embryonic hindbrain and compared it with that of Cx43 and Cx36. We found transient Cx31 expression from approximately embryonic day (E) E8-E11 in two small lateral/dorsal subgroups of cells in the hindbrain. We could show that these spots of expression corresponded to r3 and r5 and that Cx31 expression in r3 and r5 was controlled by the transcription factor Krox20. In contrast, expression of Cx43 and Cx36 started later (from E9.5 and E10.5, respectively) and was confined to longitudinal stripes of expression. In addition, from E10.5-E11.5, Cx31 was expressed by a column of cells in ventral r4, most likely representing contralateral vestibulo-acoustic efferent neurons, immediately anterior to a ventral column expressing Cx36 at the same stage. From E11.5 onward, another site of Cx31 expression was detected in the boundary cap cells in the entry/exit points of all mixed sensory/motor and in the entry points of pure sensory nerves. This expression was not present in the boundary cap cells of the exit points of pure motor nerves. So far, our analysis of the hindbrain area of Cx31-deficient embryos in terms of projections of sensory or motor neurons or in the generation or migration of neurons has not yet revealed any obvious defects.

Spinal metastases are common in patients with cancer. Following lung and liver, spine is the most common site for cancers to metastasize. Many of them are hypervascularized. These cases are a particular challenge for the surgeon and represent a significant danger of massive blood loss during surgery. Hypervascularized metastases of the cervical spine also include the risk of postoperative bleeding with severe neurological impairment. We report a case of a 67-year-old women with breast cancer (BC) metastasis within the vertebral bodies of C3 and C4 with nearly complete bony destruction of the ventral column and intraspinal tumor masses compressing the spinal cord at level C3 and C4. The hypervascularized tumor was supplied by multiple minor vessels from both vertebral arteries, too small to be coiled individually. Due to an allergy to aspirin, intravascular stenting of the vertebral arteries was not an option. We decided to perform a preoperative direct injection of onyx-18 for embolization of the tumor. Presurgical direct injection of Onyx-18 for treating hypervascular spinal metastases of breast cancer seems to be an effective and safe technique and reduces intraoperative bleeding to a minimum.

Changes in the level of cyclic 3',5'-guanosine monophosphate (cGMP) were studied one day after a surgically induced spinal cord constriction performed at the Th7 segment level in the dorsal, lateral and ventral white matter columns and in the non-compartmentalized white matter of Th5-Th6 segments, i.e., above the site of the spinal cord constriction and in Th8-Th9 segments, located below the spinal cord constriction. The midthoracic spinal cord constriction caused a significant decrease in the level of cGMP in the ventral column of Th5-Th6 segments and a significant increase in the lateral column of Th8-Th9 segments. The level of cGMP in the dorsal column, located either rostrally or caudally to the site of the spinal cord injury, remained unchanged. In addition, no significant changes in the level of cGMP were found in the non-compartmentalized white matter of Th5-Th6 and Th8-Th9 segments in response to constriction of the Th7 segment.

The spinal cord is rarely transected after spinal cord injury. Dysfunction of surviving axons, which traverse the site of spinal cord injury, appears to contribute to post-traumatic neurological deficits, although the underlying mechanisms remain unclear. The subpial rim frequently contains thinly myelinated axons which appear to conduct signals abnormally, although it is uncertain whether this truly reflects maladaptive alterations in conduction properties of injured axons during the chronic phase of spinal cord injury or whether this is merely the result of the selective survival of a subpopulation of axons. In the present study, we examined the changes in axonal conduction properties after chronic clip compression injury of the rat thoracic spinal cord, using the sucrose gap technique and quantitatively examined changes in the morphological and ultrastructural features of injured axonal fibers in order to clarify these issues. Chronically injured dorsal columns had a markedly reduced compound action potential amplitude (8.3% of control) and exhibited significantly reduced excitability. Other dysfunctional conduction properties of injured axons included a slower population conduction velocity, a longer refractory period and a greater degree of high-frequency conduction block at 200 Hz. Light microscopic and ultrastructural analysis showed numerous axons with abnormally thin myelin sheaths as well as unmyelinated axons in the injured spinal cord. The ventral column showed a reduced median axonal diameter and the lateral and dorsal columns showed increased median diameters, with evidence of abnormally large swollen axons. Plots of axonal diameter versus myelination ratio showed that post-injury, dorsal column axons of all diameters had thinner myelin sheaths. Noninjured dorsal column axons had a median myelination ratio (1.56) which was within the optimal range (1.43–1.67) for axonal conduction, whereas injured dorsal column axons had a median myelination ratio (1.33) below the optimal value. These data suggest that maladaptive alterations occur postinjury to myelin sheath thickness which reduce the efficiency of axonal signal transmission. In conclusion, chronically injured dorsal column axons show physiological evidence of dysfunction and morphological changes in axonal diameter and reduced myelination ratio. These maladaptive alterations to injured axons, including decrease in myelin thickness and the appearance of axonal swellings, contribute to the decreased excitablity of chronically injured axons. These results further clarify the mechanisms underlying neurological dysfunction after chronic neurotrauma and have significant implications regarding approaches to augment neural repair and regeneration.

The sonic motor nucleus and its fiber connections were examined in a rockfish, Sebastiscus marmoratus by means of tracer methods using horseradish peroxidase (HRP), biocytin, and carbocyanine dye (DiI). Sebastiscus has a swimbladder and a pair of extrinsic sonic/drumming muscles. The sonic muscle is ipsilaterally innervated by the occipital nerve which is composed of two ventral roots arising from the sonic motor nucleus. The sonic motor neurons are distributed in the most ventral part of the ventral column from the caudal medulla to the rostral spinal cord, and form a ventrally located columnar nucleus. Each neuron in this nucleus possesses a long thick dendrite and several short dendrites. The long dendrite extends dorsolaterally and branches in the lateral funiculus, whereas the short dendrites branch around their cell bodies. After biocytin injections into the sonic motor nucleus, two groups of premotor neurons were retrogradely labeled bilaterally, one in the dorsomedial portion of the descending octaval nucleus (DO) and the other in the medial zone of the reticular formation (RF) in the medulla. The DO premotor neurons were multipolar with several dendrites branching near the cell bodies, and the RF premotor neurons were bipolar. One of the two dendrites of the RF premotor neurons extends laterally into the ventral portion of the DO, and the other dendrite extends into the ventromedial area in the medulla. In the ventromedial dendritic field of the RF premotor neurons, descending fibers arising from the optic tectum (TO) and torus semicircularis (TS) traverse in the tractus tectobulbaris and terminate bilaterally. After DiI insertion into the ventromedial dendritic field, retrogradely labeled neurons were found bilaterally in the TS and TO. The majority of tectal neurons were located in the stratum griseum centrale. These neurons had two short basal dendrites branching in the cell layer and a long apical dendrite extending to the stratum fibrosum et griseum superficiale and stratum opticum. The toral neurons were bipolar and were distributed throughout the TS. Furthermore, biocytin injections into the medial nucleus of the lateral line system revealed that the nucleus projects bilaterally to the RF premotor neurons. These results show that premotor neurons for the sonic motor nucleus are located in the dorsomedial portion of the DO and the medial zone of the RF in the medulla. It is suggested that the sonic motor nucleus receives auditory input via the DO premotor neurons and input from RF premotor neurons which receive lateral line input via the medial nucleus, vestibular input through the lateral dendrite extending into the ventral portion of the DO, and information from the TO and TS via the tractus tectobulbaris.

Background Spinal cord stimulation and dorsal column stimulation have been used successfully in the management of visceral pain for many years. A novel technique of ventral column stimulation has been used in our institute with good outcomes since 2007. We describe a retrospective series of 26 patients with visceral neuropathic pain who were treated with neuromodulation. Methods Patients with either dermatomal hyperalgesia or sympathetically mediated neuropathic abdominal pain who had been treated with spinal cord stimulation were assessed. An independent observer conducted a face-to-face interview with each patient to collect data including demography, electrode placement, electrode mapping, and outcomes. Results There was significant reduction in visual analog pain scores from a median 9 at baseline to 4 at 26 months (p ≤ 0.05). Reduction in opioid consumption was very significant from a baseline median oral morphine equivalent of 160 mg to 26 mg (p < 0.001). In addition, quality of life, activities of daily living, and patient global impression of change improved. Conclusion There is a need to further investigate the use of ventral stimulation for visceral pain syndromes. This would need multicenter trials to collect adequate numbers of patients to allow hypothesis testing to underpin recommendations for future evidence-based therapies.

We describe a form of the autoimmune/autoinflammatory syndrome induced by adjuvants (ASIA syndrome) in commercial sheep, linked to the repetitive inoculation of aluminum-containing adjuvants through vaccination. The syndrome shows an acute phase that affects less than 0.5 % of animals in a given herd, it appears 2-6 days after an adjuvant-containing inoculation and it is characterized by an acute neurological episode with low response to external stimuli and acute menin- goencephalitis, most animals apparently recovering afterward. The chronic phase is seen in a higher proportion of flocks, it can follow the acute phase, and it is triggered by external stimuli, mostly low temperatures. The chronic phase begins with an excitatory phase, followed by weakness, extreme cachexia, tetraplegia and death. Gross lesions are related to a cachectic process with muscular atrophy, and microscopic lesions are mostly linked to a neurodegenerative process in both dorsal and ventral column of the gray matter of the spinal cord. Experimental reproduction of ovine ASIA in a small group of repeatedly vaccinated animals was successful. Detection of Al(III) in tissues indicated the presence of aluminum in the nervous tissue of experimental animals. The present report is the first description of a new sheep syndrome (ovine ASIA syndrome) linked to multiple, repetitive vaccination and that can have devastating consequences as it happened after the compulsory vaccination against bluetongue in 2008. The ovine ASIA syndrome can be used as a model of other similar diseases affecting both human and animals. A major research effort is needed in order to understand its complex pathogenesis.

Abnormal somatosensory evoked potential (SEP) (ie, prolonged latency) has been associated with poor surgical prognosis of cervical spondylotic myelopathy (CSM).To further characterize the extent of microstructural damage to the somatosensory tract in CSM patients using diffusion tensor imaging (DTI).Retrospective study.A total of 40 volunteers (25 healthy subjects and 15 CSM patients).Clinical, electrophysiological, and radiological evaluations were performed using the modified Japanese Orthopedic Association (mJOA) scoring system, SEP, and cord compression ratio in anatomic magnetic resonance (MR) images, respectively. Axial diffusion MR images were taken using a pulsed gradient, spin-echo-echo-planar imaging sequence with a 3-T MR system. The diffusion indices in different regions of the spinal cord were measured.Comparison of diffusion indices among healthy and myelopathic spinal cord with intact and impaired SEP responses were performed using one-way analysis of variance.In healthy subjects, fractional anisotropy (FA) values were higher in the dorsal (0.73±0.11) and lateral columns (0.72±0.13) than in the ventral column of white matter (0.58±0.10) (eg, at C4/5) (p.05). FA was dramatically dropped in the dorsal (0.54±0.16) and lateral columns (0.51±0.13) with little change in the ventral column (0.48±0.15) at the compressive lesions in CSM patients. There were no significant differences in the mJOA scores or cord compression ratios between CSM patients with or without abnormal SEP. However, patients with abnormal SEP showed an FA decrease in the dorsal column cephalic to the lesion (0.56±0.06) (ie, at C1/2, compared with healthy subjects [0.66±0.02]), but the same decrease was not observed for those without a SEP abnormality (0.67±0.02).Spinal tracts were not uniformly affected in the myelopathic cervical cord. Changes in diffusion indices could delineate focal or extensive myelopathic lesions in CSM, which could account for abnormal SEP. DTI analysis of spinal tracts might provide additional information not available from conventional diagnostic tools for prognosis of CSM.

A complex of three muscles (one lateral, one intermediate and one medial in position) in the clearnose skate,Raja eglanteria, is believed to be wholly, or in part, homologous to the cucullaris (trapezius). The retrograde transport of horseradish peroxidase was used to discover the central location of the motoneurons that supply each of these muscles. Motoneurons that project to the lateral muscle occupy the caudal part of the ventral nucleus of X. This nucleus is situated ventrolateral to the dorsal vagal motor column at caudal medullary levels, and lateral to the main ventral motor column of the rostral spinal cord. The axons of these motoneurons exit the medulla within the caudal vagal rootlets and course peripherally within the intestinal (visceral) ramus of the vagus nerve. Motoneurons that innervate the intermediate and medial muscles are located along the ventral border of the ventral column of gray at spinal cord segments 10–15. Their axons course peripherally within the ventral roots of spinal nerves. The caudal ventral nucleus of X, the nerve that supplies the lateral muscle, and the lateral muscle are likely homologues of the accessory nucleus, accessory nerve, and cucullaris (trapezius), respectively, among other fishes and tetrapods. Intermediate and medial muscles, based on the central location of motoneurons that supply them, are part of the longitudinal epaxial musculature and are not part of a trapezius complex.

Early myelination in zitter rat was investigated by light and electron microscopic observations, by immunostaining for myelin basic protein (MBP), proteolipid protein (PLP) and myelin-associated glycoprotein (MAG), and by morphometric analysis from the 1st to the 28th day of age. Although the commencement of myelination in zitter rats was not delayed in comparison with control rats, the density or the number of myelinated fibers in zitter rats was significantly below that in controls, both in the ventral column of the cervical spinal cord and in the optic nerve. In contrast, the density or the number of aberrant myelin sheaths was increased in zitter rats, and this difference became more marked with increasing age. The persistent presence of abnormal membranous structures associated with the oligodendroglial nuclear membrane and the increased number of aberrant myelin sheaths were characteristic to the zitter mutation, although these alterations were also observed transiently in control rats. Quantitative analysis supported the proposition that hypomyelination in zitter rats is primarily pathological and becomes more prominent with advancing age. However, the fundamental structure of the myelin lamellae appeared to be normal and the immunoreactivities for MBP, PLP and MAG were slightly delayed and weakend in comparison with age-matched controls. Thus, in zitter rat there is the functional abnormality of the oligodendrocytes to integrate the processes of membrane biosynthesis and to expel excessive production of membranous structures associated with the membranous organellae such as nuclear membrane, and it is postulated that this functional abnormality is characteristic to only the zitter mutation.

In this study we investigate the occurrence and origin of punctate nitric oxide synthase immunoreactivity in the neuropil of the ventral motor nucleus in C7-Th1 segments of the dog spine, which are supposed to be the terminal field of an ascending premotor propriospinal nitric oxide synthase-immunoreactive pathway. As the first step, nitric oxide synthase immunohistochemistry was used to distinguish nitric oxide synthase-immunoreactive staining of the ventral motor nucleus. Dense, punctate nitric oxide synthase immunoreactivity was found on control sections in the neuropil of the ventral motor nucleus. After hemisection at Th10–11, axotomy-induced retrograde changes consisting in a strong upregulation of nitric oxide synthase-containing neurons were found mostly unilaterally in lamina VIII, the medial part of lamina VII and in the pericentral region in all segments of the lumbosacral enlargement. Concurrently, a strong depletion of the punctate nitric oxide synthase immunopositivity in the neuropil of the ventral motor nucleus ipsilaterally with the hemisection was detected, thus revealing that an uncrossed ascending premotor propriospinal pathway containing a fairly high number of nitric oxide synthase-immunoreactive fibers terminates in the ventral motor nucleus. Application of the retrograde fluorescent tracer Fluorogold injected into the ventral motor nucleus and analysis of alternate sections processed for nitric oxide synthase immunocytochemistry revealed the presence of Fluorogold-labeled and nitric oxide synthase-immunoreactive axons in the ventrolateral funiculus and in the lateral and medial portions of the ventral column throughout the thoracic and upper lumbar segments. A noticeable number of Fluorogold-labeled and nitric oxide synthase-immunoreactive somata detected on consecutive sections were found in the lumbosacral enlargement, mainly in laminae VIII–IX, the medial part of lamina VII and in the pericentral region (lamina X), ipsilaterally with the injection of Fluorogold into the ventral motor nucleus. In summary, the present study provides evidence for a hitherto unknown ascending premotor propriospinal nitric oxide synthase-immunoreactive pathway connecting the lumbosacral enlargement with the motoneurons of the ventral motor nucleus in the dog.

One of the first steps in neurogenesis is the diversification of cells along the dorsoventral axis. In Drosophila the central nervous system develops from three longitudinal columns of cells: ventral cells that express the vnd/nk2 homeobox gene, intermediate cells, and dorsal cells that express the mshhomeobox gene. Here we describe a new Drosophila homeobox gene,intermediate neuroblasts defective (ind), which is expressed specifically in the intermediate column cells. ind is essential for intermediate column development: Null mutants have a transformation of intermediate to dorsal column neuroectoderm fate, and only 10% of the intermediate column neuroblasts develop. The establishment of dorsoventral column identity involves negative regulation: Vnd represses ind in the ventral column, whereas ind represses msh in the intermediate column. Vertebrate genes closely related to vnd (Nkx2.1 andNkx2.2), ind (Gsh1 and Gsh2), andmsh (Msx1 and Msx3) are expressed in corresponding ventral, intermediate, and dorsal domains during vertebrate neurogenesis, raising the possibility that dorsoventral patterning within the central nervous system is evolutionarily conserved.

The Drosophila CNS develops from three columns of neuroectodermal cells along the dorsoventral (DV) axis: ventral, intermediate, and dorsal. In this and the accompanying paper, we investigate the role of two homeobox genes, vnd andind, in establishing ventral and intermediate cell fates within the Drosophila CNS. During early neurogenesis, Vnd protein is restricted to ventral column neuroectoderm and neuroblasts; later it is detected in a complex pattern of neurons. We use molecular markers that distinguish ventral, intermediate, and dorsal column neuroectoderm and neuroblasts, and a cell lineage marker for selected neuroblasts, to show that loss of vnd transforms ventral into intermediate column identity and that specific ventral neuroblasts fail to form. Conversely, ectopic vnd produces an intermediate to ventral column transformation. Thus, vnd is necessary and sufficient to induce ventral fates and repress intermediate fates within theDrosophila CNS. Vertebrate homologs of vnd(Nkx2.1 and 2.2) are similarly expressed in the ventral CNS, raising the possibility that DV patterning within the CNS is evolutionarily conserved.

Anterior surgery is frequently chosen for treatment of cervical myelopathy. However, intraoperative spinal cord recording has rarely been used to monitor the function of the ventral columns. We report a method of monitoring evoked spinal cord potentials useful for detection of minor injury of the anterior spinal cord. Evoked spinal cord potentials elicited in cats by thoracic spinal cord and labyrinth stimulation were studied. Evoked intraspinal field potentials recorded after labyrinth stimulation were confirmed to originate from the vestibulospinal tract in the ventral columns. Low-amplitude potentials were recorded from the posterior epidural space. However, this method has not been used clinically because of difficulty in obtaining selective stimulation in humans. Spinal cord potentials evoked by thoracic stimulation were recorded from the anterior and posterior epidural spaces. The amplitude of the potentials was large enough to permit quantitation of neural function. We confirmed that anterior recording was more sensitive in detecting ventral column injury than posterior recording was. Based on these findings, we used anterior recording from the disc clinically for anterior spinal cord monitoring during anterior cervical surgery.

Slow negative (N) and slow positive (P) waves are frequently produced in the posterior epidural space at the lumbosacral enlargement by epidural stimulation of the rostral part of human spinal cord. The production of these slow potentials are thought to be responsible for analgesia at the stimulated segment as well as below that level. In order to define the spinal tract which mediates these slow potentials, we stimulated directly or from the epidural space the dorsal, dorsolateral, lateral and ventral columns at the cervical or thoracic level, and epidurally recorded spinal cord potentials (des.SCPs) at the lumbosacral enlargement in 7 patients who underwent spine or spinal cord surgery. The des.SCPs recorded in the lumbosacral enlargement consisted of polyphasic spike potentials followed by slow N and P waves. At a near threshold level of stimulus intensity the slow N and P potentials were consistently elicited only by stimulation of the dorsal column. The slow waves were also produced by intense stimulation of other tracts, but remained significantly (P < 0.05−P

Acidic excitatory amino acids have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). We now report that, in addition to selective regional reductions in endogenous aspartate and glutamate, N-acetylaspartate (NAA), and N-acetylaspartylglutamate (NAAG) are also decreased in the CNS, whereas the activity of N-acetylated-alpha-linked-amino dipeptidase (NAALADase) is increased. In cervical cord, the concentrations of aspartate and glutamate were decreased significantly in the ventral horn; NAA was decreased in the ventral horn, dorsal horn and ventral column, whereas NAAG was decreased in all regions of the cord examined, except the posterior column. NAALADase activity was increased in the ventral column. In motor cortex of ALS patients, aspartate and glutamate were decreased and NAALADase activity was increased in both gray and white matter; whereas NAAG was decreased in gray matter alone. None of these parameters was affected in the cerebral cortex of the Huntington's patients. Of the markers examined, the alterations in the levels of NAAG most closely parallel the cellular neuropathology in ALS.

This study describes the cytoarchitecture and the projections of second order neurons of the area octavolateralis in Xenopus laevis as revealed by application of HRP. There are three octavolateral sensory columns in the alar plate, a dorsal, a medial and a ventral column. The dorsal and medial appear to be unimodal and receive acoustic and lateral line input respectively. The ventral column receives a mixed sensory input: the dorsal part from all inner ear organs and the ventral part only from the vestibule.

The spheroids in the brain and spinal cord were examined lightmicroscopically in 55 dogs (1 month to 18 years of age). Their shape varied from round to oval and was sometimes ellipsoidal or irregularly elongated, and the size ranged from 5 to 200μm in diameter. The spheroids were acidophilic and argyrophilic, histochemically positive for protein reaction but negative for nucleic acid reaction. As a new finding, PAS positive concentric round bodies were found within the spheroids in aged dogs. In the brain, the most constantly affected area was the dorsal column nuclei, especially in the gracile nucleus in the medulla oblongata. In the spinal cord, caudal segments from the lumbar to the cauda equina were noticed as the predilection sites, and the spheroids were more frequently found in the substantia intermedia hnd ventral column. The occurrence of the spheroids tended to increase with age and was marked in chronic wasting disease such as tumor cachexia and severe filariasis.

The distribution of neural crest derived cells (NC) in the heart of quail-chick chimeric embryos was analyzed three-dimensionally after computer reconstruction. During the division of the truncus arteriosus into the aorta and the pulmonary trunk, ventral and dorsal columns of NC-derived cells were found in the truncal swellings. These columns were elongations from the aorticopulmonary (AP) septum. The dorsal column extended more proximally than did the ventral column. Around hatching, NC-derived cells located between the proximal aorta and the pulmonary trunk, differentiated into cartilage and connective tissue. They formed a part of the cardiac skeleton. A small number of NC-derived cells were scattered in the cusps of the arterial valves. Cells derived from the right NC were located around the aorta and the right arch arteries but not around the distal pulmonary trunk and the left arch arteries. At the proximal level, cells derived from the right NC were located in both the dorsal and ventral columns. These results suggest that the AP septum is mainly formed by NC-derived cells, right and left NC cells migrating into assigned areas in the heart. Location of two columns of NC-derived cells may support a translocation hypothesis for the AP septum during truncal division.

The distribution of substance P (SP) in the rat spinal cord was investigated by peroxidase-anti-peroxidase (PAP) immunocytochemistry. A dense network of SP-immunoreactive fibers and terminals was detected in the ventral column of the rostral lumbar cord with a different density and extent from the other segmental levels. These fibers and terminals were accumulated within and around the centromedial nucleus (CM) of the L1 and L2 segments, with some bundles of immunoreactive fibers between the CM and other areas; i.e. laminae V and X and the contralateral CM. They formed a dense network, such as in arborization of immunoreactive fibers and terminals on the transverse plane and in a comb-shaped structure on the horizontal plane. The origin of the SP in this network was examined. It was determined that neither a total transection of spinal cord at a low thoracic level or mid-lumbar level, nor at an ipsilateral or bilateral section of the 3–5 dorsal roots, containing L1 and L2 roots, induced any visible changes in the SP staining pattern. An intrathecal injection of colchicine revealed the presence of SP-immunoreactive neurons in the dorsal horn and intermediate gray matter at the spinal cord including the rostral lumbar cord. The present findings suggested that the majority of SP immunoreactivities in the above network are derived from local circuit interneurons of the spinal cord.

The functional organization of the motoneurons in the spinal cord of the sea robin, Prionotus carolinus, was studied by means of retrograde transport of horseradish peroxidase (HRP). This species has a complex pectoral apparatus which includes not only a webbed fin, but also three independently mobile fin rays. The motoneurons in the rostral spinal cord fall into two longitudinal columns: dorsal and ventral. The motoneurons of the ventral column innervate the appendicular musculature of the pectoral apparatus. Within the ventral motor column of the rostral spinal cord, four distinct motoneuronal pools were found. The largest pool is situated at the rostral-most end of the spinal cord and contains the motoneurons that innervate the musculature of the webbed pectoral fin. The motoneurons that innervate the fin rays are located in sequentially more posterior pools so that the anteroventral fin ray is controlled by motoneurons situated farthest caudally. The somatotopic arrangement exactly corresponds to the sensory somatotopy determined previously. Furthermore, each fin ray has its sensory representation in a unique accessory spinal lobe which is connected in a reflex fashion to the motoneuronal pool that provides motor output to the same fin ray.