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Sample records for spinal neurons responding

  1. Characterization of upper thoracic spinal neurons responding to esophageal distension in diabetic rats

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    Qin, Chao; Ghorbani, Marie L M; Wu, Mingyuan

    2008-01-01

    The aim of this study was to examine spinal neuronal processing of innocuous and noxious mechanical inputs from the esophagus in diabetic rats. Streptozotocin (50 mg/kg, ip) was used to induce diabetes in 15 male Sprague-Dawley rats, and vehicle (10 mM citrate buffer) was injected into 15 rats...

  2. Preprotachykinin A is expressed by a distinct population of excitatory neurons in the mouse superficial spinal dorsal horn including cells that respond to noxious and pruritic stimuli.

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    Gutierrez-Mecinas, Maria; Bell, Andrew M; Marin, Alina; Taylor, Rebecca; Boyle, Kieran A; Furuta, Takahiro; Watanabe, Masahiko; Polgár, Erika; Todd, Andrew J

    2017-03-01

    The superficial dorsal horn, which is the main target for nociceptive and pruritoceptive primary afferents, contains a high density of excitatory interneurons. Our understanding of their roles in somatosensory processing has been restricted by the difficulty of distinguishing functional populations among these cells. We recently defined 3 nonoverlapping populations among the excitatory neurons, based on the expression of neurotensin, neurokinin B, and gastrin-releasing peptide. Here we identify and characterise another population: neurons that express the tachykinin peptide substance P. We show with immunocytochemistry that its precursor protein (preprotachykinin A, PPTA) can be detected in ∼14% of lamina I-II neurons, and these are concentrated in the outer part of lamina II. Over 80% of the PPTA-positive cells lack the transcription factor Pax2 (which determines an inhibitory phenotype), and these account for ∼15% of the excitatory neurons in this region. They are different from the neurotensin, neurokinin B, or gastrin-releasing peptide neurons, although many of them contain somatostatin, which is widely expressed among superficial dorsal horn excitatory interneurons. We show that many of these cells respond to noxious thermal and mechanical stimuli and to intradermal injection of pruritogens. Finally, we demonstrate that these cells can also be identified in a knock-in Cre mouse line (Tac1), although our findings suggest that there is an additional population of neurons that transiently express PPTA. This population of substance P-expressing excitatory neurons is likely to play an important role in the transmission of signals that are perceived as pain and itch.

  3. Selective loss of alpha motor neurons with sparing of gamma motor neurons and spinal cord cholinergic neurons in a mouse model of spinal muscular atrophy.

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    Powis, Rachael A; Gillingwater, Thomas H

    2016-03-01

    Spinal muscular atrophy (SMA) is a neuromuscular disease characterised primarily by loss of lower motor neurons from the ventral grey horn of the spinal cord and proximal muscle atrophy. Recent experiments utilising mouse models of SMA have demonstrated that not all motor neurons are equally susceptible to the disease, revealing that other populations of neurons can also be affected. Here, we have extended investigations of selective vulnerability of neuronal populations in the spinal cord of SMA mice to include comparative assessments of alpha motor neuron (α-MN) and gamma motor neuron (γ-MN) pools, as well as other populations of cholinergic neurons. Immunohistochemical analyses of late-symptomatic SMA mouse spinal cord revealed that numbers of α-MNs were significantly reduced at all levels of the spinal cord compared with controls, whereas numbers of γ-MNs remained stable. Likewise, the average size of α-MN cell somata was decreased in SMA mice with no change occurring in γ-MNs. Evaluation of other pools of spinal cord cholinergic neurons revealed that pre-ganglionic sympathetic neurons, central canal cluster interneurons, partition interneurons and preganglionic autonomic dorsal commissural nucleus neuron numbers all remained unaffected in SMA mice. Taken together, these findings indicate that α-MNs are uniquely vulnerable among cholinergic neuron populations in the SMA mouse spinal cord, with γ-MNs and other cholinergic neuronal populations being largely spared. © 2015 Anatomical Society.

  4. Motor neurons and the generation of spinal motor neurons diversity

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    Nicolas eStifani

    2014-10-01

    Full Text Available Motor neurons (MNs are neuronal cells located in the central nervous system (CNS controlling a variety of downstream targets. This function infers the existence of MN subtypes matching the identity of the targets they innervate. To illustrate the mechanism involved in the generation of cellular diversity and the acquisition of specific identity, this review will focus on spinal motor neurons (SpMNs that have been the core of significant work and discoveries during the last decades. SpMNs are responsible for the contraction of effector muscles in the periphery. Humans possess more than 500 different skeletal muscles capable to work in a precise time and space coordination to generate complex movements such as walking or grasping. To ensure such refined coordination, SpMNs must retain the identity of the muscle they innervate.Within the last two decades, scientists around the world have produced considerable efforts to elucidate several critical steps of SpMNs differentiation. During development, SpMNs emerge from dividing progenitor cells located in the medial portion of the ventral neural tube. MN identities are established by patterning cues working in cooperation with intrinsic sets of transcription factors. As the embryo develop, MNs further differentiate in a stepwise manner to form compact anatomical groups termed pools connecting to a unique muscle target. MN pools are not homogeneous and comprise subtypes according to the muscle fibers they innervate.This article aims to provide a global view of MN classification as well as an up-to-date review of the molecular mechanisms involved in the generation of SpMN diversity. Remaining conundrums will be discussed since a complete understanding of those mechanisms constitutes the foundation required for the elaboration of prospective MN regeneration therapies.

  5. Dynamics of intrinsic electrophysiological properties in spinal cord neurones

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    Russo, R E; Hounsgaard, J

    1999-01-01

    The spinal cord is engaged in a wide variety of functions including generation of motor acts, coding of sensory information and autonomic control. The intrinsic electrophysiological properties of spinal neurones represent a fundamental building block of the spinal circuits executing these tasks. ....... Specialised, cell specific electrophysiological phenotypes gradually differentiate during development and are continuously adjusted in the adult animal by metabotropic synaptic interactions and activity-dependent plasticity to meet a broad range of functional demands....

  6. Spinal sensory projection neuron responses to spinal cord stimulation are mediated by circuits beyond gate control.

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    Zhang, Tianhe C; Janik, John J; Peters, Ryan V; Chen, Gang; Ji, Ru-Rong; Grill, Warren M

    2015-07-01

    Spinal cord stimulation (SCS) is a therapy used to treat intractable pain with a putative mechanism of action based on the Gate Control Theory. We hypothesized that sensory projection neuron responses to SCS would follow a single stereotyped response curve as a function of SCS frequency, as predicted by the Gate Control circuit. We recorded the responses of antidromically identified sensory projection neurons in the lumbar spinal cord during 1- to 150-Hz SCS in both healthy rats and neuropathic rats following chronic constriction injury (CCI). The relationship between SCS frequency and projection neuron activity predicted by the Gate Control circuit accounted for a subset of neuronal responses to SCS but could not account for the full range of observed responses. Heterogeneous responses were classifiable into three additional groups and were reproduced using computational models of spinal microcircuits representing other interactions between nociceptive and nonnociceptive sensory inputs. Intrathecal administration of bicuculline, a GABAA receptor antagonist, increased spontaneous and evoked activity in projection neurons, enhanced excitatory responses to SCS, and reduced inhibitory responses to SCS, suggesting that GABAA neurotransmission plays a broad role in regulating projection neuron activity. These in vivo and computational results challenge the Gate Control Theory as the only mechanism underlying SCS and refine our understanding of the effects of SCS on spinal sensory neurons within the framework of contemporary understanding of dorsal horn circuitry. Copyright © 2015 the American Physiological Society.

  7. Mirror neurons: reflecting on the motor cortex and spinal cord.

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    Schieber, Marc H

    2013-02-18

    Neurons in the monkey motor cortex that project to the spinal cord to control particular muscle contractions and movements have been found to discharge again while the monkey simply watches another primate make similar movements: monkey see; monkey not do. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Emergence of Serotonergic Neurons After Spinal Cord Injury in Turtles

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    Gabriela Fabbiani

    2018-03-01

    Full Text Available Plasticity of neural circuits takes many forms and plays a fundamental role in regulating behavior to changing demands while maintaining stability. For example, during spinal cord development neurotransmitter identity in neurons is dynamically adjusted in response to changes in the activity of spinal networks. It is reasonable to speculate that this type of plasticity might occur also in mature spinal circuits in response to injury. Because serotonergic signaling has a central role in spinal cord functions, we hypothesized that spinal cord injury (SCI in the fresh water turtle Trachemys scripta elegans may trigger homeostatic changes in serotonergic innervation. To test this possibility we performed immunohistochemistry for serotonin (5-HT and key molecules involved in the determination of the serotonergic phenotype before and after SCI. We found that as expected, in the acute phase after injury the dense serotonergic innervation was strongly reduced. However, 30 days after SCI the population of serotonergic cells (5-HT+ increased in segments caudal to the lesion site. These cells expressed the neuronal marker HuC/D and the transcription factor Nkx6.1. The new serotonergic neurons did not incorporate the thymidine analog 5-bromo-2′-deoxyuridine (BrdU and did not express the proliferating cell nuclear antigen (PCNA indicating that novel serotonergic neurons were not newborn but post-mitotic cells that have changed their neurochemical identity. Switching towards a serotonergic neurotransmitter phenotype may be a spinal cord homeostatic mechanism to compensate for the loss of descending serotonergic neuromodulation, thereby helping the outstanding functional recovery displayed by turtles. The 5-HT1A receptor agonist (±-8-Hydroxy-2-dipropylaminotetralin hydrobromide (8-OH-DPAT blocked the increase in 5-HT+ cells suggesting 5-HT1A receptors may trigger the respecification process.

  9. Neuronal Population Activity in Spinal Motor Circuits

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    Berg, Rune W.

    2017-01-01

    -electrode technology it was possible to reveal the spiking activity of larger parts of the network. A series of experiments revealed unexpected features of spinal networks, such as multiple spiking regimes and lognormal firing rate distributions. The lognormality renders the widespread idea of a typical firing rate...

  10. Dorsal spinal cord stimulation obtunds the capacity of intrathoracic extracardiac neurons to transduce myocardial ischemia.

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    Ardell, Jeffrey L; Cardinal, René; Vermeulen, Michel; Armour, J Andrew

    2009-08-01

    Populations of intrathoracic extracardiac neurons transduce myocardial ischemia, thereby contributing to sympathetic control of regional cardiac indices during such pathology. Our objective was to determine whether electrical neuromodulation using spinal cord stimulation (SCS) modulates such local reflex control. In 10 anesthetized canines, middle cervical ganglion neurons were identified that transduce the ventricular milieu. Their capacity to transduce a global (rapid ventricular pacing) vs. regional (transient regional ischemia) ventricular stress was tested before and during SCS (50 Hz, 0.2 ms duration at 90% MT) applied to the dorsal aspect of the T1 to T4 spinal cord. Rapid ventricular pacing and transient myocardial ischemia both activated cardiac-related middle cervical ganglion neurons. SCS obtunded their capacity to reflexly respond to the regional ventricular ischemia, but not rapid ventricular pacing. In conclusion, spinal cord inputs to the intrathoracic extracardiac nervous system obtund the latter's capacity to transduce regional ventricular ischemia, but not global cardiac stress. Given the substantial body of literature indicating the adverse consequences of excessive adrenergic neuronal excitation on cardiac function, these data delineate the intrathoracic extracardiac nervous system as a potential target for neuromodulation therapy in minimizing such effects.

  11. Selected statins produce rapid spinal motor neuron loss in vitro

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    Murinson Beth B

    2012-06-01

    Full Text Available Abstract Background Hmg-CoA reductase inhibitors (statins are widely used to prevent disease associated with vascular disease and hyperlipidemia. Although side effects are uncommon, clinical observations suggest statin exposure may exacerbate neuromuscular diseases, including peripheral neuropathy and amyotrophic lateral sclerosis. Although some have postulated class-effects, prior studies of hepatocytes and myocytes indicate that the statins may exhibit differential effects. Studies of neuronal cells have been limited. Methods We examined the effects of statins on cultured neurons and Schwann cells. Cultured spinal motor neurons were grown on transwell inserts and assessed for viability using immunochemical staining for SMI-32. Cultured cortical neurons and Schwann cells were assessed using dynamic viability markers. Results 7 days of exposure to fluvastatin depleted spinal motor neurons in a dose-dependent manner with a KD of  Conclusions It is known from pharmacokinetic studies that daily treatment of young adults with fluvastatin can produce serum levels in the single micromolar range. We conclude that specific mechanisms may explain neuromuscular disease worsening with statins and further study is needed.

  12. Effect of acute lateral hemisection of the spinal cord on spinal neurons of postural networks

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    Zelenin, P. V.; Lyalka, V. F.; Orlovsky, G. N.; Deliagina, T. G.

    2016-01-01

    In quadrupeds, acute lateral hemisection of the spinal cord (LHS) severely impairs postural functions, which recover over time. Postural limb reflexes (PLRs) represent a substantial component of postural corrections in intact animals. The aim of the present study was to characterize the effects of acute LHS on two populations of spinal neurons (F and E) mediating PLRs. For this purpose, in decerebrate rabbits, responses of individual neurons from L5 to stimulation causing PLRs were recorded before and during reversible LHS (caused by temporal cold block of signal transmission in lateral spinal pathways at L1), as well as after acute surgical (Sur) LHS at L1. Results obtained after Sur-LHS were compared to control data obtained in our previous study. We found that acute LHS caused disappearance of PLRs on the affected side. It also changed a proportion of different types of neurons on that side. A significant decrease and increase in the proportion of F- and non-modulated neurons, respectively, was found. LHS caused a significant decrease in most parameters of activity in F-neurons located in the ventral horn on the lesioned side and in E-neurons of the dorsal horn on both sides. These changes were caused by a significant decrease in the efficacy of posture-related sensory input from the ipsilateral limb to F-neurons, and from the contralateral limb to both F- and E-neurons. These distortions in operation of postural networks underlie the impairment of postural control after acute LHS, and represent a starting point for the subsequent recovery of postural functions. PMID:27702647

  13. Survival motor neuron protein in motor neurons determines synaptic integrity in spinal muscular atrophy.

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    Martinez, Tara L; Kong, Lingling; Wang, Xueyong; Osborne, Melissa A; Crowder, Melissa E; Van Meerbeke, James P; Xu, Xixi; Davis, Crystal; Wooley, Joe; Goldhamer, David J; Lutz, Cathleen M; Rich, Mark M; Sumner, Charlotte J

    2012-06-20

    The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein and results in severe muscle weakness. In SMA mice, synaptic dysfunction of both neuromuscular junctions (NMJs) and central sensorimotor synapses precedes motor neuron cell death. To address whether this synaptic dysfunction is due to SMN deficiency in motor neurons, muscle, or both, we generated three lines of conditional SMA mice with tissue-specific increases in SMN expression. All three lines of mice showed increased survival, weights, and improved motor behavior. While increased SMN expression in motor neurons prevented synaptic dysfunction at the NMJ and restored motor neuron somal synapses, increased SMN expression in muscle did not affect synaptic function although it did improve myofiber size. Together these data indicate that both peripheral and central synaptic integrity are dependent on motor neurons in SMA, but SMN may have variable roles in the maintenance of these different synapses. At the NMJ, it functions at the presynaptic terminal in a cell-autonomous fashion, but may be necessary for retrograde trophic signaling to presynaptic inputs onto motor neurons. Importantly, SMN also appears to function in muscle growth and/or maintenance independent of motor neurons. Our data suggest that SMN plays distinct roles in muscle, NMJs, and motor neuron somal synapses and that restored function of SMN at all three sites will be necessary for full recovery of muscle power.

  14. Lidocaine Inhibits HCN Currents in Rat Spinal Substantia Gelatinosa Neurons

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    Hu, Tao; Liu, Nana; Lv, Minhua; Ma, Longxian; Peng, Huizhen; Peng, Sicong

    2016-01-01

    BACKGROUND: Lidocaine, which blocks voltage-gated sodium channels, is widely used in surgical anesthesia and pain management. Recently, it has been proposed that the hyperpolarization-activated cyclic nucleotide (HCN) channel is one of the other novel targets of lidocaine. Substantia gelatinosa in the spinal dorsal horn, which plays key roles in modulating nociceptive information from primary afferents, comprises heterogeneous interneurons that can be electrophysiologically categorized by firing pattern. Our previous study demonstrated that a substantial proportion of substantia gelatinosa neurons reveal the presence of HCN current (Ih); however, the roles of lidocaine and HCN channel expression in different types of substantia gelatinosa neurons remain unclear. METHODS: By using the whole-cell patch-clamp technique, we investigated the effect of lidocaine on Ih in rat substantia gelatinosa neurons of acute dissociated spinal cord slices. RESULTS: We found that lidocaine rapidly decreased the peak Ih amplitude with an IC50 of 80 μM. The inhibition rate on Ih was not significantly different with a second application of lidocaine in the same neuron. Tetrodotoxin, a sodium channel blocker, did not affect lidocaine’s effect on Ih. In addition, lidocaine shifted the half-activation potential of Ih from −109.7 to −114.9 mV and slowed activation. Moreover, the reversal potential of Ih was shifted by −7.5 mV by lidocaine. In the current clamp, lidocaine decreased the resting membrane potential, increased membrane resistance, delayed rebound depolarization latency, and reduced the rebound spike frequency. We further found that approximately 58% of substantia gelatinosa neurons examined expressed Ih, in which most of them were tonically firing. CONCLUSIONS: Our studies demonstrate that lidocaine strongly inhibits Ih in a reversible and concentration-dependent manner in substantia gelatinosa neurons, independent of tetrodotoxin-sensitive sodium channels. Thus, our

  15. Optogenetic identification of hypothalamic orexin neuron projections to paraventricular spinally projecting neurons.

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    Dergacheva, Olga; Yamanaka, Akihiro; Schwartz, Alan R; Polotsky, Vsevolod Y; Mendelowitz, David

    2017-04-01

    Orexin neurons, and activation of orexin receptors, are generally thought to be sympathoexcitatory; however, the functional connectivity between orexin neurons and a likely sympathetic target, the hypothalamic spinally projecting neurons (SPNs) in the paraventricular nucleus of the hypothalamus (PVN) has not been established. To test the hypothesis that orexin neurons project directly to SPNs in the PVN, channelrhodopsin-2 (ChR2) was selectively expressed in orexin neurons to enable photoactivation of ChR2-expressing fibers while examining evoked postsynaptic currents in SPNs in rat hypothalamic slices. Selective photoactivation of orexin fibers elicited short-latency postsynaptic currents in all SPNs tested ( n = 34). These light-triggered responses were heterogeneous, with a majority being excitatory glutamatergic responses (59%) and a minority of inhibitory GABAergic (35%) and mixed glutamatergic and GABAergic currents (6%). Both glutamatergic and GABAergic responses were present in the presence of tetrodotoxin and 4-aminopyridine, suggesting a monosynaptic connection between orexin neurons and SPNs. In addition to generating postsynaptic responses, photostimulation facilitated action potential firing in SPNs (current clamp configuration). Glutamatergic, but not GABAergic, postsynaptic currents were diminished by application of the orexin receptor antagonist almorexant, indicating orexin release facilitates glutamatergic neurotransmission in this pathway. This work identifies a neuronal circuit by which orexin neurons likely exert sympathoexcitatory control of cardiovascular function. NEW & NOTEWORTHY This is the first study to establish, using innovative optogenetic approaches in a transgenic rat model, that there are robust heterogeneous projections from orexin neurons to paraventricular spinally projecting neurons, including excitatory glutamatergic and inhibitory GABAergic neurotransmission. Endogenous orexin release modulates glutamatergic, but not

  16. Spinal cord injury triggers sensitization of wide dynamic range dorsal horn neurons in segments rostral to the injury.

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    Zhang, Haijun; Xie, Wenrui; Xie, Yikuan

    2005-09-07

    A spinal cord injury (SCI) was produced in adult rats by complete spinal cord transection at L6-S1. Neuropathic pain behaviors similar to the chronic central pain (CCP) syndrome in human, such as thermal hyperalgesia, mechanical allodynia and autotomy, were present in these rats after spinal cord injury. Meanwhile, wide dynamic range (WDR) neurons recorded in the spinal dorsal horn rostral to the lesion responded as high frequency of spontaneous activities, long duration of after-discharges to noxious electrical stimuli and an augmented wind-up to 0.5 Hz stimuli. By using bupivacaine powder, a sodium channel blocker, at the locus of transection immediate after nerve injury, the chronic pain behaviors were prevented; the hyperexcitability of WDR neurons was also substantially reduced. It is suggested that spinal cord transection induces the CCP syndromes, which may be evoked and maintained by the hyperexcitability in WDR neurons rostrally. Reducing the neuronal activity at the site of lesion following injury may prevent the development of CCP after SCI.

  17. Responses of spinal dorsal horn neurons to foot movements in rats with a sprained ankle

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    Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon

    2011-01-01

    Acute ankle injuries are common problems and often lead to persistent pain. To investigate the underlying mechanism of ankle sprain pain, the response properties of spinal dorsal horn neurons were examined after ankle sprain. Acute ankle sprain was induced manually by overextending the ankle of a rat hindlimb in a direction of plantarflexion and inversion. The weight-bearing ratio (WBR) of the affected foot was used as an indicator of pain. Single unit activities of dorsal horn neurons in response to plantarflexion and inversion of the foot or ankle compression were recorded from the medial part of the deep dorsal horn, laminae IV-VI, in normal and ankle-sprained rats. One day after ankle sprain, rats showed significantly reduced WBRs on the affected foot, and this reduction was partially restored by systemic morphine. The majority of deep dorsal horn neurons responded to a single ankle stimulus modality. After ankle sprain, the mean evoked response rates were significantly increased, and afterdischarges were developed in recorded dorsal horn neurons. The ankle sprain-induced enhanced evoked responses were significantly reduced by morphine, which was reversed by naltrexone. The data indicate that movement-specific dorsal horn neuron responses were enhanced after ankle sprain in a morphine-dependent manner, thus suggesting that hyperactivity of dorsal horn neurons is an underlying mechanism of pain after ankle sprain. PMID:21389306

  18. Ablating spinal NK1-bearing neurons eliminates the development of pain and reduces spinal neuronal hyperexcitability and inflammation from mechanical joint injury in the rat.

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    Weisshaar, Christine L; Winkelstein, Beth A

    2014-04-01

    The facet joint is a common source of pain, especially from mechanical injury. Although chronic pain is associated with altered spinal glial and neuronal responses, the contribution of specific spinal cells to joint pain is not understood. This study used the neurotoxin [Sar(9),Met(O2)(11)]-substance P-saporin (SSP-SAP) to selectively eliminate spinal cells expressing neurokinin-1 receptor (NK1R) in a rat model of painful facet joint injury to determine the role of those spinal neurons in pain from facet injury. Following spinal administration of SSP-SAP or its control (blank-SAP), a cervical facet injury was imposed and behavioral sensitivity was assessed. Spinal extracellular recordings were made on day 7 to classify neurons and quantify evoked firing. Spinal glial activation and interleukin 1αα (IL1α) expression also were evaluated. SSP-SAP prevented the development of mechanical hyperalgesia that is induced by joint injury and reduced NK1R expression and mechanically evoked neuronal firing in the dorsal horn. SSP-SAP also prevented a shift toward wide dynamic range neurons that is seen after injury. Spinal astrocytic activation and interleukin 1α (IL1α) expression were reduced to sham levels with SSP-SAP treatment. These results suggest that spinal NK1R-bearing cells are critical in initiating spinal nociception and inflammation associated with a painful mechanical joint injury. Results demonstrate that cells expressing NK1R in the spinal cord are critical for the development of joint pain, spinal neuroplasticity, and inflammation after trauma to the joint. These findings have utility for understanding mechanisms of joint pain and developing potential targets to treat pain. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

  19. Spinal Muscular Atrophy: More than a Disease of Motor Neurons?

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    Nash, L A; Burns, J K; Chardon, J Warman; Kothary, R; Parks, R J

    2016-01-01

    Spinal muscular atrophy (SMA) is the most common genetically inherited neurodegenerative disease resulting in infant mortality. SMA is caused by genetic deletion or mutation in the survival of motor neuron 1 (SMN1) gene, which results in reduced levels of the survival of motor neuron (SMN) protein. SMN protein deficiency preferentially affects α- motor neurons, leading to their degeneration and subsequent atrophy of limb and trunk muscles, progressing to death in severe forms of the disease. More recent studies have shown that SMN protein depletion is detrimental to the functioning of other tissues including skeletal muscle, heart, autonomic and enteric nervous systems, metabolic/endocrine (e.g. pancreas), lymphatic, bone and reproductive system. In this review, we summarize studies discussing SMN protein's function in various cell and tissue types and their involvement in the context of SMA disease etiology. Taken together, these studies indicate that SMA is a multi-organ disease, which suggests that truly effective disease intervention may require body-wide correction of SMN protein levels. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  20. Recapitulation of spinal motor neuron-specific disease phenotypes in a human cell model of spinal muscular atrophy.

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    Wang, Zhi-Bo; Zhang, Xiaoqing; Li, Xue-Jun

    2013-03-01

    Establishing human cell models of spinal muscular atrophy (SMA) to mimic motor neuron-specific phenotypes holds the key to understanding the pathogenesis of this devastating disease. Here, we developed a closely representative cell model of SMA by knocking down the disease-determining gene, survival motor neuron (SMN), in human embryonic stem cells (hESCs). Our study with this cell model demonstrated that knocking down of SMN does not interfere with neural induction or the initial specification of spinal motor neurons. Notably, the axonal outgrowth of spinal motor neurons was significantly impaired and these disease-mimicking neurons subsequently degenerated. Furthermore, these disease phenotypes were caused by SMN-full length (SMN-FL) but not SMN-Δ7 (lacking exon 7) knockdown, and were specific to spinal motor neurons. Restoring the expression of SMN-FL completely ameliorated all of the disease phenotypes, including specific axonal defects and motor neuron loss. Finally, knockdown of SMN-FL led to excessive mitochondrial oxidative stress in human motor neuron progenitors. The involvement of oxidative stress in the degeneration of spinal motor neurons in the SMA cell model was further confirmed by the administration of N-acetylcysteine, a potent antioxidant, which prevented disease-related apoptosis and subsequent motor neuron death. Thus, we report here the successful establishment of an hESC-based SMA model, which exhibits disease gene isoform specificity, cell type specificity, and phenotype reversibility. Our model provides a unique paradigm for studying how motor neurons specifically degenerate and highlights the potential importance of antioxidants for the treatment of SMA.

  1. Selective vulnerability of spinal and cortical motor neuron subpopulations in delta7 SMA mice.

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    d'Errico, Paolo; Boido, Marina; Piras, Antonio; Valsecchi, Valeria; De Amicis, Elena; Locatelli, Denise; Capra, Silvia; Vagni, Francesco; Vercelli, Alessandro; Battaglia, Giorgio

    2013-01-01

    Loss of the survival motor neuron gene (SMN1) is responsible for spinal muscular atrophy (SMA), the most common inherited cause of infant mortality. Even though the SMA phenotype is traditionally considered as related to spinal motor neuron loss, it remains debated whether the specific targeting of motor neurons could represent the best therapeutic option for the disease. We here investigated, using stereological quantification methods, the spinal cord and cerebral motor cortex of ∆7 SMA mice during development, to verify extent and selectivity of motor neuron loss. We found progressive post-natal loss of spinal motor neurons, already at pre-symptomatic stages, and a higher vulnerability of motor neurons innervating proximal and axial muscles. Larger motor neurons decreased in the course of disease, either for selective loss or specific developmental impairment. We also found a selective reduction of layer V pyramidal neurons associated with layer V gliosis in the cerebral motor cortex. Our data indicate that in the ∆7 SMA model SMN loss is critical for the spinal cord, particularly for specific motor neuron pools. Neuronal loss, however, is not selective for lower motor neurons. These data further suggest that SMA pathogenesis is likely more complex than previously anticipated. The better knowledge of SMA models might be instrumental in shaping better therapeutic options for affected patients.

  2. Three-dimensional distribution of sensory stimulation-evoked neuronal activity of spinal dorsal horn neurons analyzed by in vivo calcium imaging.

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    Nishida, Kazuhiko; Matsumura, Shinji; Taniguchi, Wataru; Uta, Daisuke; Furue, Hidemasa; Ito, Seiji

    2014-01-01

    The spinal dorsal horn comprises heterogeneous populations of interneurons and projection neurons, which form neuronal circuits crucial for processing of primary sensory information. Although electrophysiological analyses have uncovered sensory stimulation-evoked neuronal activity of various spinal dorsal horn neurons, monitoring these activities from large ensembles of neurons is needed to obtain a comprehensive view of the spinal dorsal horn circuitry. In the present study, we established in vivo calcium imaging of multiple spinal dorsal horn neurons by using a two-photon microscope and extracted three-dimensional neuronal activity maps of these neurons in response to cutaneous sensory stimulation. For calcium imaging, a fluorescence resonance energy transfer (FRET)-based calcium indicator protein, Yellow Cameleon, which is insensitive to motion artifacts of living animals was introduced into spinal dorsal horn neurons by in utero electroporation. In vivo calcium imaging following pinch, brush, and heat stimulation suggests that laminar distribution of sensory stimulation-evoked neuronal activity in the spinal dorsal horn largely corresponds to that of primary afferent inputs. In addition, cutaneous pinch stimulation elicited activities of neurons in the spinal cord at least until 2 spinal segments away from the central projection field of primary sensory neurons responsible for the stimulated skin point. These results provide a clue to understand neuronal processing of sensory information in the spinal dorsal horn.

  3. Three-dimensional distribution of sensory stimulation-evoked neuronal activity of spinal dorsal horn neurons analyzed by in vivo calcium imaging.

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    Kazuhiko Nishida

    Full Text Available The spinal dorsal horn comprises heterogeneous populations of interneurons and projection neurons, which form neuronal circuits crucial for processing of primary sensory information. Although electrophysiological analyses have uncovered sensory stimulation-evoked neuronal activity of various spinal dorsal horn neurons, monitoring these activities from large ensembles of neurons is needed to obtain a comprehensive view of the spinal dorsal horn circuitry. In the present study, we established in vivo calcium imaging of multiple spinal dorsal horn neurons by using a two-photon microscope and extracted three-dimensional neuronal activity maps of these neurons in response to cutaneous sensory stimulation. For calcium imaging, a fluorescence resonance energy transfer (FRET-based calcium indicator protein, Yellow Cameleon, which is insensitive to motion artifacts of living animals was introduced into spinal dorsal horn neurons by in utero electroporation. In vivo calcium imaging following pinch, brush, and heat stimulation suggests that laminar distribution of sensory stimulation-evoked neuronal activity in the spinal dorsal horn largely corresponds to that of primary afferent inputs. In addition, cutaneous pinch stimulation elicited activities of neurons in the spinal cord at least until 2 spinal segments away from the central projection field of primary sensory neurons responsible for the stimulated skin point. These results provide a clue to understand neuronal processing of sensory information in the spinal dorsal horn.

  4. Ionic mechanisms of spinal neuronal cold hypersensitivity in ciguatera.

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    Patel, Ryan; Brice, Nicola L; Lewis, Richard J; Dickenson, Anthony H

    2015-12-01

    Cold hypersensitivity is evident in a range of neuropathies and can evoke sensations of paradoxical burning cold pain. Ciguatoxin poisoning is known to induce a pain syndrome caused by consumption of contaminated tropical fish that can persist for months and include pruritus and cold allodynia; at present no suitable treatment is available. This study examined, for the first time, the neural substrates and molecular components of Pacific ciguatoxin-2-induced cold hypersensitivity. Electrophysiological recordings of dorsal horn lamina V/VI wide dynamic range neurones were made in non-sentient rats. Subcutaneous injection of 10 nm ciguatoxin-2 into the receptive field increased neuronal responses to innocuous and noxious cooling. In addition, neuronal responses to low-threshold but not noxious punctate mechanical stimuli were also elevated. The resultant cold hypersensitivity was not reversed by 6-({2-[2-fluoro-6-(trifluoromethyl)phenoxy]-2-methylpropyl}carbamoyl)pyridine-3-carboxylic acid, an antagonist of transient receptor potential melastatin 8 (TRPM8). Both mechanical and cold hypersensitivity were completely prevented by co-injection with the Nav 1.8 antagonist A803467, whereas the transient receptor potential ankyrin 1 (TRPA1) antagonist A967079 only prevented hypersensitivity to innocuous cooling and partially prevented hypersensitivity to noxious cooling. In naive rats, neither innocuous nor noxious cold-evoked neuronal responses were inhibited by antagonists of Nav 1.8, TRPA1 or TRPM8 alone. Ciguatoxins may confer cold sensitivity to a subpopulation of cold-insensitive Nav 1.8/TRPA1-positive primary afferents, which could underlie the cold allodynia reported in ciguatera. These data expand the understanding of central spinal cold sensitivity under normal conditions and the role of these ion channels in this translational rat model of ciguatoxin-induced hypersensitivity. © 2015 The Authors. European Journal of Neuroscience published by Federation of

  5. Activation of AMPK by OSU53 protects spinal cord neurons from oxidative stress.

    Science.gov (United States)

    Xu, Jun; Wu, Liang; Zhang, Yiming; Gu, Huijie; Huang, Zhongyue; Zhou, Kaifeng; Yin, Xiaofan

    2017-12-22

    The present study tested the potential effect of OSU53, a novel AMPK activator, against hydrogen peroxide (H2O2)-induced spinal cord neuron damages. Treatment with OSU53 attenuated H2O2-induced death and apoptosis of primary murine spinal cord neurons. OSU53 activated AMPK signaling, which is required for its actions in spinal cord neurons. The AMPK inhibitor Compound C or AMPKα1 siRNA almost abolished OSU53-mediated neuroprotection against H2O2. On the other hand, sustained-activation of AMPK by introducing the constitutive-active AMPKα1 mimicked OSU53's actions, and protected spinal cord neurons from oxidative stress. OSU53 significantly attenuated H2O2-induced reactive oxygen species production, lipid peroxidation and DNA damages in spinal cord neurons. Additionally, OSU53 increased NADPH content and heme oxygenase-1 mRNA expression in H2O2-treated spinal cord neurons. Together, we indicate that targeted-activation of AMPK by OSU53 protects spinal cord neurons from oxidative stress.

  6. Effects of triphenyltin on glycinergic transmission on rat spinal neurons.

    Science.gov (United States)

    Noma, Kazuki; Akaike, Hironari; Kurauchi, Yuki; Katsuki, Hiroshi; Oyama, Yasuo; Akaike, Norio

    2018-02-13

    Glycine is a fast inhibitory transmitter like γ-aminobutyric acid in the mammalian spinal cord and brainstem, and it is involved in motor reflex, nociception, and neuronal development. Triphenyltin (TPT) is an organometallic compound causing environmental hazard to many wild creatures. Our previous findings show that TPT ultimately induces a drain and/or exhaustion of glutamate in excitatory presynaptic nerve terminals, resulted in blockage of neurotransmission as well as methylmercury. Therefore, we have investigated the neurotoxic mechanism how TPT modulates inhibitory glycinergic transmission in the synaptic bouton preparation of rat isolated spinal neurons using a patch clamp technique. TPT at environmentally relevant concentrations (3-300 nM) significantly increased the number of frequency of glycinergic spontaneous and miniature inhibitory postsynaptic currents (sIPSC and mIPSC) without affecting the current amplitude and decay time. The TPT effects were also observed in external Ca 2+ -free solution containing tetrodotoxin (TTX) but removed in Ca 2+ -free solution with both TTX and BAPTA-AM (Ca 2+ chelator). On the other hand, the amplitude of glycinergic evoked inhibitory postsynaptic currents (eIPSCs) increased with decreasing failure rate (Rf) and paired pulse ratio (PPR) in the presence of 300 nM TPT. At a high concentration (1 µM), TPT completely blocked eIPSCs after a transient facilitation. Overall, these results suggest that TPT directly acts transmitter-releasing machinery in glycinergic nerve terminals. Effects of TPT on the nerve terminals releasing fast transmitters were greater in the order of glycinergic > glutamatergic > GABAergic ones. Thus, TPT is supposed to cause a strong synaptic modulations on glycinergic neurotransmission in wild creatures. Copyright © 2018. Published by Elsevier Inc.

  7. Functional properties of parietal hand manipulation-related neurons and mirror neurons responding to vision of own hand action.

    Science.gov (United States)

    Maeda, Kazutaka; Ishida, Hiroaki; Nakajima, Katsumi; Inase, Masahiko; Murata, Akira

    2015-03-01

    Parietofrontal pathways play an important role in visually guided motor control. In this pathway, hand manipulation-related neurons in the inferior parietal lobule represent 3-D properties of an object and motor patterns to grasp it. Furthermore, mirror neurons show visual responses that are concerned with the actions of others and motor-related activity during execution of the same grasping action. Because both of these categories of neurons integrate visual and motor signals, these neurons may play a role in motor control based on visual feedback signals. The aim of this study was to investigate whether these neurons in inferior parietal lobule including the anterior intraparietal area and PFG of macaques represent visual images of the monkey's own hand during a self-generated grasping action. We recorded 235 neurons related to hand manipulation tasks. Of these, 54 responded to video clips of the monkey's own hand action, the same as visual feedback during that action or clips of the experimenter's hand action in a lateral view. Of these 54 neurons, 25 responded to video clips of the monkey's own hand, even without an image of the target object. We designated these 25 neurons as "hand-type." Thirty-three of 54 neurons that were defined as mirror neurons showed visual responses to the experimenter's action and motor responses. Thirteen of these mirror neurons were classified as hand-type. These results suggest that activity of hand manipulation-related and mirror neurons in anterior intraparietal/PFG plays a fundamental role in monitoring one's own body state based on visual feedback.

  8. Hindbrain V2a neurons in the excitation of spinal locomotor circuits during zebrafish swimming.

    Science.gov (United States)

    Kimura, Yukiko; Satou, Chie; Fujioka, Shunji; Shoji, Wataru; Umeda, Keiko; Ishizuka, Toru; Yawo, Hiromu; Higashijima, Shin-ichi

    2013-05-20

    During locomotion in vertebrates, reticulospinal neurons in the hindbrain play critical roles in providing descending excitation to the spinal cord locomotor systems. However, despite the fact that many genes that are used to classify the neuronal identities of neurons in the hindbrain have been identified, the molecular identity of the reticulospinal neurons that are critically involved in locomotor drive is not well understood. Chx10-expressing neurons (V2a neurons) are ipsilaterally projecting glutamatergic neurons in the spinal cord and the hindbrain. Many of the V2a neurons in the hindbrain are known to project to the spinal cord in zebrafish, making hindbrain V2a neurons a prime candidate in descending locomotor drive. We investigated the roles of hindbrain V2a neurons using optogenetic and electrophysiological approaches. The forced activation of hindbrain V2a neurons using channelrhodopsin efficiently evoked swimming, whereas the forced inactivation of them using Archearhodopsin3 or Halorhodpsin reliably stopped ongoing swimming. Electrophysiological recordings of two populations of hindbrain reticulospinal V2a neurons showed that they were active during swimming. One population of neurons, small V2a neurons in the caudal hindbrain, fired with low rhythmicity, whereas the other population of neurons, large reticulospinal V2a neurons, called MiV1 neurons, fired more rhythmically. These results indicated that hindbrain reticulospinal V2a neurons play critical roles in providing excitation to the spinal locomotor circuits during swimming by providing both tonic and phasic inputs to the circuits. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. miR-155 Deletion in Mice Overcomes Neuron-Intrinsic and Neuron-Extrinsic Barriers to Spinal Cord Repair

    Science.gov (United States)

    Mandrekar-Colucci, Shweta; Hall, Jodie C.E.; Sweet, David R.; Schmitt, Philipp J.; Xu, Xinyang; Guan, Zhen; Mo, Xiaokui; Guerau-de-Arellano, Mireia

    2016-01-01

    Axon regeneration after spinal cord injury (SCI) fails due to neuron-intrinsic mechanisms and extracellular barriers including inflammation. microRNA (miR)-155–5p is a small, noncoding RNA that negatively regulates mRNA translation. In macrophages, miR-155-5p is induced by inflammatory stimuli and elicits a response that could be toxic after SCI. miR-155 may also independently alter expression of genes that regulate axon growth in neurons. Here, we hypothesized that miR-155 deletion would simultaneously improve axon growth and reduce neuroinflammation after SCI by acting on both neurons and macrophages. New data show that miR-155 deletion attenuates inflammatory signaling in macrophages, reduces macrophage-mediated neuron toxicity, and increases macrophage-elicited axon growth by ∼40% relative to control conditions. In addition, miR-155 deletion increases spontaneous axon growth from neurons; adult miR-155 KO dorsal root ganglion (DRG) neurons extend 44% longer neurites than WT neurons. In vivo, miR-155 deletion augments conditioning lesion-induced intraneuronal expression of SPRR1A, a regeneration-associated gene; ∼50% more injured KO DRG neurons expressed SPRR1A versus WT neurons. After dorsal column SCI, miR-155 KO mouse spinal cord has reduced neuroinflammation and increased peripheral conditioning-lesion-enhanced axon regeneration beyond the epicenter. Finally, in a model of spinal contusion injury, miR-155 deletion improves locomotor function at postinjury times corresponding with the arrival and maximal appearance of activated intraspinal macrophages. In miR-155 KO mice, improved locomotor function is associated with smaller contusion lesions and decreased accumulation of inflammatory macrophages. Collectively, these data indicate that miR-155 is a novel therapeutic target capable of simultaneously overcoming neuron-intrinsic and neuron-extrinsic barriers to repair after SCI. SIGNIFICANCE STATEMENT Axon regeneration after spinal cord injury (SCI) fails

  10. Distinct populations of neurons respond to emotional valence and arousal in the human subthalamic nucleus.

    Science.gov (United States)

    Sieger, Tomáš; Serranová, Tereza; Růžička, Filip; Vostatek, Pavel; Wild, Jiří; Štastná, Daniela; Bonnet, Cecilia; Novák, Daniel; Růžička, Evžen; Urgošík, Dušan; Jech, Robert

    2015-03-10

    Both animal studies and studies using deep brain stimulation in humans have demonstrated the involvement of the subthalamic nucleus (STN) in motivational and emotional processes; however, participation of this nucleus in processing human emotion has not been investigated directly at the single-neuron level. We analyzed the relationship between the neuronal firing from intraoperative microrecordings from the STN during affective picture presentation in patients with Parkinson's disease (PD) and the affective ratings of emotional valence and arousal performed subsequently. We observed that 17% of neurons responded to emotional valence and arousal of visual stimuli according to individual ratings. The activity of some neurons was related to emotional valence, whereas different neurons responded to arousal. In addition, 14% of neurons responded to visual stimuli. Our results suggest the existence of neurons involved in processing or transmission of visual and emotional information in the human STN, and provide evidence of separate processing of the affective dimensions of valence and arousal at the level of single neurons as well.

  11. In vivo characterization of microglial engulfment of dying neurons in the zebrafish spinal cord

    Science.gov (United States)

    Morsch, Marco; Radford, Rowan; Lee, Albert; Don, Emily K.; Badrock, Andrew P.; Hall, Thomas E.; Cole, Nicholas J.; Chung, Roger

    2015-01-01

    Microglia are specialized phagocytes in the vertebrate central nervous system (CNS). As the resident immune cells of the CNS they play an important role in the removal of dying neurons during both development and in several neuronal pathologies. Microglia have been shown to prevent the diffusion of damaging degradation products of dying neurons by engulfment and ingestion. Here we describe a live imaging approach that uses UV laser ablation to selectively stress and kill spinal neurons and visualize the clearance of neuronal remnants by microglia in the zebrafish spinal cord. In vivo imaging confirmed the motile nature of microglia within the uninjured spinal cord. However, selective neuronal ablation triggered rapid activation of microglia, leading to phagocytic uptake of neuronal debris by microglia within 20–30 min. This process of microglial engulfment is highly dynamic, involving the extension of processes toward the lesion site and consequently the ingestion of the dying neuron. 3D rendering analysis of time-lapse recordings revealed the formation of phagosome-like structures in the activated microglia located at the site of neuronal ablation. This real-time representation of microglial phagocytosis in the living zebrafish spinal cord provides novel opportunities to study the mechanisms of microglia-mediated neuronal clearance. PMID:26379496

  12. Responses of rat spinal dorsal horn neurons to intracutaneous microinjection of histamine, capsaicin, and other irritants.

    Science.gov (United States)

    Carstens, E

    1997-05-01

    To investigate the spinal processing of cutaneous pruritic and algesic stimuli, single-unit recordings were made from wide-dynamic-range-type lumbar spinal dorsal horn neurons in pentobarbital-sodium-anesthetized rats. Neuronal responses were recorded to mechanical and noxious thermal stimuli, as well as to microinjection (1 microl) of histamine (0.01-10% = 9 x 10(-1)-9 x 10(-4) M), capsaicin (0.1% = 3.3 x 10(-3) M), or other algesic chemicals into skin within the receptive field via intracutaneously placed needles. Most (84%) of the 89 neurons responded to intracutaneous (i.c.) microinjection of histamine with a brief phasic discharge followed by an afterdischarge of variable (s to min) duration. Ten minutes after i.c. microinjection of histamine (but not NaCl), there was a significant increase in the mean area of the low-threshold (but not high-threshold) portion of unit mechanical receptive fields. However, responses to graded pressure stimuli were not significantly affected after histamine. Responses did not exhibit significant tachyphylaxis when histamine microinjections were repeated at 5- or 10-min intervals. Unit responses significantly increased in a dose-related manner to microinjection of histamine at concentrations ranging across 4 orders of magnitude. Within 30 s after i.c. microinjection of the H1 antagonist cetirizine, unit responses to i.c. histamine delivered at the same skin site were significantly attenuated. Unit responses to histamine, as well as to noxious thermal stimulation, were significantly reduced after systemic administration of morphine (3.5 mg/kg i.p.) in a naloxone-reversible manner. Application of a mechanical rub, scratch, or a noxious heat stimulus during the unit's ongoing response to i.c. histamine produced a brief and marked excitation, often followed by a period of reduced ongoing discharge. Unit responses to histamine were markedly suppressed by electrical stimulation in the midbrain periaqueductal gray. Most (79%) histamine

  13. Histological and functional benefit following transplantation of motor neuron progenitors to the injured rat spinal cord.

    Directory of Open Access Journals (Sweden)

    Sharyn L Rossi

    2010-07-01

    Full Text Available Motor neuron loss is characteristic of cervical spinal cord injury (SCI and contributes to functional deficit.In order to investigate the amenability of the injured adult spinal cord to motor neuron differentiation, we transplanted spinal cord injured animals with a high purity population of human motor neuron progenitors (hMNP derived from human embryonic stem cells (hESCs. In vitro, hMNPs displayed characteristic motor neuron-specific markers, a typical electrophysiological profile, functionally innervated human or rodent muscle, and secreted physiologically active growth factors that caused neurite branching and neuronal survival. hMNP transplantation into cervical SCI sites in adult rats resulted in suppression of intracellular signaling pathways associated with SCI pathogenesis, which correlated with greater endogenous neuronal survival and neurite branching. These neurotrophic effects were accompanied by significantly enhanced performance on all parameters of the balance beam task, as compared to controls. Interestingly, hMNP transplantation resulted in survival, differentiation, and site-specific integration of hMNPs distal to the SCI site within ventral horns, but hMNPs near the SCI site reverted to a neuronal progenitor state, suggesting an environmental deficiency for neuronal maturation associated with SCI.These findings underscore the barriers imposed on neuronal differentiation of transplanted cells by the gliogenic nature of the injured spinal cord, and the physiological relevance of transplant-derived neurotrophic support to functional recovery.

  14. Ex vivo infection of human embryonic spinal cord neurons prior to transplantation into adult mouse cord

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    Dénes Ádám

    2010-05-01

    Full Text Available Abstract Background Genetically modified pseudorabies virus (Prv proved suitable for the delivery of foreign genes to rodent embryonic neurons ex vivo and maintaining foreign gene expression after transplantation into spinal cord in our earlier study. The question arose of whether human embryonic neurons, which are known to be more resistant to Prv, could also be infected with a mutant Prv. Specifically, we investigated whether a mutant Prv with deleted ribonucleotide reductase and early protein 0 genes has the potential to deliver marker genes (gfp and β-gal into human embryonic spinal cord neurons and whether the infected neurons maintain expression after transplantation into adult mouse cord. Results The results revealed that the mutant Prv effectively infected human embryonic spinal cord neurons ex vivo and the grafted cells exhibited reporter gene expression for several weeks. Grafting of infected human embryonic cells into the spinal cord of immunodeficient (rnu-/rnu- mice resulted in the infection of some of the host neurons. Discussion These results suggest that Prv is suitable for the delivery of foreign genes into transplantable human cells. This delivery method may offer a new approach to use genetically modified cells for grafting in animal models where spinal cord neuronal loss or axon degeneration occurs.

  15. Mimicking the neurotrophic factor profile of embryonic spinal cord controls the differentiation potential of spinal progenitors into neuronal cells.

    Directory of Open Access Journals (Sweden)

    Masaya Nakamura

    Full Text Available Recent studies have indicated that the choice of lineage of neural progenitor cells is determined, at least in part, by environmental factors, such as neurotrophic factors. Despite extensive studies using exogenous neurotrophic factors, the effect of endogenous neurotrophic factors on the differentiation of progenitor cells remains obscure. Here we show that embryonic spinal cord derived-progenitor cells express both ciliary neurotrophic factor (CNTF and brain-derived neurotrophic factor (BDNF mRNA before differentiation. BDNF gene expression significantly decreases with their differentiation into the specific lineage, whereas CNTF gene expression significantly increases. The temporal pattern of neurotrophic factor gene expression in progenitor cells is similar to that of the spinal cord during postnatal development. Approximately 50% of spinal progenitor cells differentiated into astrocytes. To determine the effect of endogenous CNTF on their differentiation, we neutralized endogenous CNTF by administration of its polyclonal antibody. Neutralization of endogenous CNTF inhibited the differentiation of progenitor cells into astrocytes, but did not affect the numbers of neurons or oligodendrocytes. Furthermore, to mimic the profile of neurotrophic factors in the spinal cord during embryonic development, we applied BDNF or neurotrophin (NT-3 exogenously in combination with the anti-CNTF antibody. The exogenous application of BDNF or NT-3 promoted the differentiation of these cells into neurons or oligodendrocytes, respectively. These findings suggest that endogenous CNTF and exogenous BDNF and NT-3 play roles in the differentiation of embryonic spinal cord derived progenitor cells into astrocytes, neurons and oligodendrocytes, respectively.

  16. Transmitters and pathways mediating inhibition of spinal itch-signaling neurons by scratching and other counterstimuli.

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    Tasuku Akiyama

    Full Text Available Scratching relieves itch, but the underlying neural mechanisms are poorly understood. We presently investigated a role for the inhibitory neurotransmitters GABA and glycine in scratch-evoked inhibition of spinal itch-signaling neurons in a mouse model of chronic dry skin itch. Superficial dorsal horn neurons ipsilateral to hindpaw dry skin treatment exhibited a high level of spontaneous firing that was significantly attenuated by cutaneous scratching, pinch and noxious heat. Scratch-evoked inhibition was nearly abolished by spinal delivery of the glycine antagonist, strychnine, and was markedly attenuated by respective GABA(A and GABA(B antagonists bicuculline and saclofen. Scratch-evoked inhibition was also significantly attenuated (but not abolished by interruption of the upper cervical spinal cord, indicating the involvement of both segmental and suprasegmental circuits that engage glycine- and GABA-mediated inhibition of spinal itch-signaling neurons by noxious counterstimuli.

  17. Sensory neurons do not induce motor neuron loss in a human stem cell model of spinal muscular atrophy.

    Science.gov (United States)

    Schwab, Andrew J; Ebert, Allison D

    2014-01-01

    Spinal muscular atrophy (SMA) is an autosomal recessive disorder leading to paralysis and early death due to reduced SMN protein. It is unclear why there is such a profound motor neuron loss, but recent evidence from fly and mouse studies indicate that cells comprising the whole sensory-motor circuit may contribute to motor neuron dysfunction and loss. Here, we used induced pluripotent stem cells derived from SMA patients to test whether sensory neurons directly contribute to motor neuron loss. We generated sensory neurons from SMA induced pluripotent stem cells and found no difference in neuron generation or survival, although there was a reduced calcium response to depolarizing stimuli. Using co-culture of SMA induced pluripotent stem cell derived sensory neurons with control induced pluripotent stem cell derived motor neurons, we found no significant reduction in motor neuron number or glutamate transporter boutons on motor neuron cell bodies or neurites. We conclude that SMA sensory neurons do not overtly contribute to motor neuron loss in this human stem cell system.

  18. Peripheral nerve injury increases glutamate-evoked calcium mobilization in adult spinal cord neurons

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    Doolen Suzanne

    2012-07-01

    Full Text Available Abstract Background Central sensitization in the spinal cord requires glutamate receptor activation and intracellular Ca2+ mobilization. We used Fura-2 AM bulk loading of mouse slices together with wide-field Ca2+ imaging to measure glutamate-evoked increases in extracellular Ca2+ to test the hypotheses that: 1. Exogenous application of glutamate causes Ca2+ mobilization in a preponderance of dorsal horn neurons within spinal cord slices taken from adult mice; 2. Glutamate-evoked Ca2+ mobilization is associated with spontaneous and/or evoked action potentials; 3. Glutamate acts at glutamate receptor subtypes to evoked Ca2+ transients; and 4. The magnitude of glutamate-evoked Ca2+ responses increases in the setting of peripheral neuropathic pain. Results Bath-applied glutamate robustly increased [Ca2+]i in 14.4 ± 2.6 cells per dorsal horn within a 440 x 330 um field-of-view, with an average time-to-peak of 27 s and decay of 112 s. Repeated application produced sequential responses of similar magnitude, indicating the absence of sensitization, desensitization or tachyphylaxis. Ca2+ transients were glutamate concentration-dependent with a Kd = 0.64 mM. Ca2+ responses predominantly occurred on neurons since: 1 Over 95% of glutamate-responsive cells did not label with the astrocyte marker, SR-101; 2 62% of fura-2 AM loaded cells exhibited spontaneous action potentials; 3 75% of cells that responded to locally-applied glutamate with a rise in [Ca2+]i also showed a significant increase in AP frequency upon a subsequent glutamate exposure; 4 In experiments using simultaneous on-cell recordings and Ca2+ imaging, glutamate elicited a Ca2+ response and an increase in AP frequency. AMPA/kainate (CNQX- and AMPA (GYKI 52466-selective receptor antagonists significantly attenuated glutamate-evoked increases in [Ca2+]i, while NMDA (AP-5, kainate (UBP-301 and class I mGluRs (AIDA did not. Compared to sham controls, peripheral nerve injury

  19. Peripheral nerve injury increases glutamate-evoked calcium mobilization in adult spinal cord neurons.

    Science.gov (United States)

    Doolen, Suzanne; Blake, Camille B; Smith, Bret N; Taylor, Bradley K

    2012-07-28

    Central sensitization in the spinal cord requires glutamate receptor activation and intracellular Ca2+ mobilization. We used Fura-2 AM bulk loading of mouse slices together with wide-field Ca2+ imaging to measure glutamate-evoked increases in extracellular Ca2+ to test the hypotheses that: 1. Exogenous application of glutamate causes Ca2+ mobilization in a preponderance of dorsal horn neurons within spinal cord slices taken from adult mice; 2. Glutamate-evoked Ca2+ mobilization is associated with spontaneous and/or evoked action potentials; 3. Glutamate acts at glutamate receptor subtypes to evoked Ca2+ transients; and 4. The magnitude of glutamate-evoked Ca2+ responses increases in the setting of peripheral neuropathic pain. Bath-applied glutamate robustly increased [Ca2+]i in 14.4 ± 2.6 cells per dorsal horn within a 440 x 330 um field-of-view, with an average time-to-peak of 27 s and decay of 112 s. Repeated application produced sequential responses of similar magnitude, indicating the absence of sensitization, desensitization or tachyphylaxis. Ca2+ transients were glutamate concentration-dependent with a Kd = 0.64 mM. Ca2+ responses predominantly occurred on neurons since: 1) Over 95% of glutamate-responsive cells did not label with the astrocyte marker, SR-101; 2) 62% of fura-2 AM loaded cells exhibited spontaneous action potentials; 3) 75% of cells that responded to locally-applied glutamate with a rise in [Ca2+]i also showed a significant increase in AP frequency upon a subsequent glutamate exposure; 4) In experiments using simultaneous on-cell recordings and Ca2+ imaging, glutamate elicited a Ca2+ response and an increase in AP frequency. AMPA/kainate (CNQX)- and AMPA (GYKI 52466)-selective receptor antagonists significantly attenuated glutamate-evoked increases in [Ca2+]i, while NMDA (AP-5), kainate (UBP-301) and class I mGluRs (AIDA) did not. Compared to sham controls, peripheral nerve injury significantly decreased mechanical paw

  20. Organization of left-right coordination of neuronal activity in the mammalian spinal cord

    DEFF Research Database (Denmark)

    Shevtsova, Natalia A.; Talpalar, Adolfo E.; Markin, Sergey N.

    2015-01-01

    . In this study, we construct and analyse two computational models of spinal locomotor circuits consisting of left and right rhythm generators interacting bilaterally via several neuronal pathways mediated by different CINs. The CIN populations incorporated in the models include the genetically identified......Different locomotor gaits in mammals, such as walking or galloping, are produced by coordinated activity in neuronal circuits in the spinal cord. Coordination of neuronal activity between left and right sides of the cord is provided by commissural interneurons (CINs), whose axons cross the midline...... and the left-right synchronous hopping-like pattern in mutants lacking specific neuron classes, and speed-dependent asymmetric changes of flexor and extensor phase durations. The models provide insights into the architecture of spinal network and the organization of parallel inhibitory and excitatory CIN...

  1. Physiological, anatomical and genetic identification of CPG neurons in the developing mammalian spinal cord

    DEFF Research Database (Denmark)

    Kiehn, Ole; Butt, Simon J.B.

    2003-01-01

    . These latter experiments have defined EphA4 as a molecular marker for mammalian excitatory hindlimb CPG neurons. We also review genetic approaches that can be applied to the mouse spinal cord. These include methods for identifying sub-populations of neurons by genetically encoded reporters, techniques to trace...... network connectivity with cell-specific genetically encoded tracers, and ways to selectively ablate or eliminate neuron populations from the CPG. We propose that by applying a multidisciplinary approach it will be possible to understand the network structure of the mammalian locomotor CPG......The basic motor patterns underlying rhythmic limb movements during locomotion are generated by neuronal networks located within the spinal cord. These networks are called Central Pattern Generators (CPGs). Isolated spinal cord preparations from newborn rats and mice have become increasingly...

  2. Vestibular nucleus neurons respond to hindlimb movement in the conscious cat.

    Science.gov (United States)

    McCall, Andrew A; Miller, Derek M; DeMayo, William M; Bourdages, George H; Yates, Bill J

    2016-10-01

    The limbs constitute the sole interface with the ground during most waking activities in mammalian species; it is therefore expected that somatosensory inputs from the limbs provide important information to the central nervous system for balance control. In the decerebrate cat model, the activity of a subset of neurons in the vestibular nuclei (VN) has been previously shown to be modulated by hindlimb movement. However, decerebration can profoundly alter the effects of sensory inputs on the activity of brain stem neurons, resulting in epiphenomenal responses. Thus, before this study, it was unclear whether and how somatosensory inputs from the limb affected the activity of VN neurons in conscious animals. We recorded brain stem neuronal activity in the conscious cat and characterized the responses of VN neurons to flexion and extension hindlimb movements and to whole body vertical tilts (vestibular stimulation). Among 96 VN neurons whose activity was modulated by vestibular stimulation, the firing rate of 65 neurons (67.7%) was also affected by passive hindlimb movement. VN neurons in conscious cats most commonly encoded hindlimb movement irrespective of the direction of movement (n = 33, 50.8%), in that they responded to all flexion and extension movements of the limb. Other VN neurons overtly encoded information about the direction of hindlimb movement (n = 27, 41.5%), and the remainder had more complex responses. These data confirm that hindlimb somatosensory and vestibular inputs converge onto VN neurons of the conscious cat, suggesting that VN neurons integrate somatosensory inputs from the limbs in computations that affect motor outflow to maintain balance. Copyright © 2016 the American Physiological Society.

  3. Long descending cervical propriospinal neurons differ from thoracic propriospinal neurons in response to low thoracic spinal injury

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    Stelzner Dennis J

    2010-11-01

    Full Text Available Abstract Background Propriospinal neurons, with axonal projections intrinsic to the spinal cord, have shown a greater regenerative response than supraspinal neurons after axotomy due to spinal cord injury (SCI. Our previous work focused on the response of axotomized short thoracic propriospinal (TPS neurons following a low thoracic SCI (T9 spinal transection or moderate spinal contusion injury in the rat. The present investigation analyzes the intrinsic response of cervical propriospinal neurons having long descending axons which project into the lumbosacral enlargement, long descending propriospinal tract (LDPT axons. These neurons also were axotomized by T9 spinal injury in the same animals used in our previous study. Results Utilizing laser microdissection (LMD, qRT-PCR, and immunohistochemistry, we studied LDPT neurons (located in the C5-C6 spinal segments between 3-days, and 1-month following a low thoracic (T9 spinal cord injury. We examined the response of 89 genes related to growth factors, cell surface receptors, apoptosis, axonal regeneration, and neuroprotection/cell survival. We found a strong and significant down-regulation of ~25% of the genes analyzed early after injury (3-days post-injury with a sustained down-regulation in most instances. In the few genes that were up-regulated (Actb, Atf3, Frs2, Hspb1, Nrap, Stat1 post-axotomy, the expression for all but one was down-regulated by 2-weeks post-injury. We also compared the uninjured TPS control neurons to the uninjured LDPT neurons used in this experiment for phenotypic differences between these two subpopulations of propriospinal neurons. We found significant differences in expression in 37 of the 84 genes examined between these two subpopulations of propriospinal neurons with LDPT neurons exhibiting a significantly higher base line expression for all but 3 of these genes compared to TPS neurons. Conclusions Taken collectively these data indicate a broad overall down

  4. The anthropomorphic brain : The mirror neuron system responds to human and robotic actions

    NARCIS (Netherlands)

    Gazzola, V.; Rizzolatti, G.; Wicker, B.; Keysers, C.

    2007-01-01

    In humans and monkeys the mirror neuron system transforms seen actions into our inner representation of these actions. Here we asked if this system responds also if we see an industrial robot perform similar actions. We localised the motor areas involved in the execution of hand actions, presented

  5. Serotonin Promotes Development and Regeneration of Spinal Motor Neurons in Zebrafish.

    Science.gov (United States)

    Barreiro-Iglesias, Antón; Mysiak, Karolina S; Scott, Angela L; Reimer, Michell M; Yang, Yujie; Becker, Catherina G; Becker, Thomas

    2015-11-03

    In contrast to mammals, zebrafish regenerate spinal motor neurons. During regeneration, developmental signals are re-deployed. Here, we show that, during development, diffuse serotonin promotes spinal motor neuron generation from pMN progenitor cells, leaving interneuron numbers unchanged. Pharmacological manipulations and receptor knockdown indicate that serotonin acts at least in part via 5-HT1A receptors. In adults, serotonin is supplied to the spinal cord mainly (90%) by descending axons from the brain. After a spinal lesion, serotonergic axons degenerate caudal to the lesion but sprout rostral to it. Toxin-mediated ablation of serotonergic axons also rostral to the lesion impaired regeneration of motor neurons only there. Conversely, intraperitoneal serotonin injections doubled numbers of new motor neurons and proliferating pMN-like progenitors caudal to the lesion. Regeneration of spinal-intrinsic serotonergic interneurons was unaltered by these manipulations. Hence, serotonin selectively promotes the development and adult regeneration of motor neurons in zebrafish. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Maturation of Spinal Motor Neurons Derived from Human Embryonic Stem Cells

    Science.gov (United States)

    Takazawa, Tomonori; Croft, Gist F.; Amoroso, Mackenzie W.; Studer, Lorenz; Wichterle, Hynek; MacDermott, Amy B.

    2012-01-01

    Our understanding of motor neuron biology in humans is derived mainly from investigation of human postmortem tissue and more indirectly from live animal models such as rodents. Thus generation of motor neurons from human embryonic stem cells and human induced pluripotent stem cells is an important new approach to model motor neuron function. To be useful models of human motor neuron function, cells generated in vitro should develop mature properties that are the hallmarks of motor neurons in vivo such as elaborated neuronal processes and mature electrophysiological characteristics. Here we have investigated changes in morphological and electrophysiological properties associated with maturation of neurons differentiated from human embryonic stem cells expressing GFP driven by a motor neuron specific reporter (Hb9::GFP) in culture. We observed maturation in cellular morphology seen as more complex neurite outgrowth and increased soma area over time. Electrophysiological changes included decreasing input resistance and increasing action potential firing frequency over 13 days in vitro. Furthermore, these human embryonic stem cell derived motor neurons acquired two physiological characteristics that are thought to underpin motor neuron integrated function in motor circuits; spike frequency adaptation and rebound action potential firing. These findings show that human embryonic stem cell derived motor neurons develop functional characteristics typical of spinal motor neurons in vivo and suggest that they are a relevant and useful platform for studying motor neuron development and function and for modeling motor neuron diseases. PMID:22802953

  7. miR-155 Deletion in Mice Overcomes Neuron-Intrinsic and Neuron-Extrinsic Barriers to Spinal Cord Repair.

    Science.gov (United States)

    Gaudet, Andrew D; Mandrekar-Colucci, Shweta; Hall, Jodie C E; Sweet, David R; Schmitt, Philipp J; Xu, Xinyang; Guan, Zhen; Mo, Xiaokui; Guerau-de-Arellano, Mireia; Popovich, Phillip G

    2016-08-10

    Axon regeneration after spinal cord injury (SCI) fails due to neuron-intrinsic mechanisms and extracellular barriers including inflammation. microRNA (miR)-155-5p is a small, noncoding RNA that negatively regulates mRNA translation. In macrophages, miR-155-5p is induced by inflammatory stimuli and elicits a response that could be toxic after SCI. miR-155 may also independently alter expression of genes that regulate axon growth in neurons. Here, we hypothesized that miR-155 deletion would simultaneously improve axon growth and reduce neuroinflammation after SCI by acting on both neurons and macrophages. New data show that miR-155 deletion attenuates inflammatory signaling in macrophages, reduces macrophage-mediated neuron toxicity, and increases macrophage-elicited axon growth by ∼40% relative to control conditions. In addition, miR-155 deletion increases spontaneous axon growth from neurons; adult miR-155 KO dorsal root ganglion (DRG) neurons extend 44% longer neurites than WT neurons. In vivo, miR-155 deletion augments conditioning lesion-induced intraneuronal expression of SPRR1A, a regeneration-associated gene; ∼50% more injured KO DRG neurons expressed SPRR1A versus WT neurons. After dorsal column SCI, miR-155 KO mouse spinal cord has reduced neuroinflammation and increased peripheral conditioning-lesion-enhanced axon regeneration beyond the epicenter. Finally, in a model of spinal contusion injury, miR-155 deletion improves locomotor function at postinjury times corresponding with the arrival and maximal appearance of activated intraspinal macrophages. In miR-155 KO mice, improved locomotor function is associated with smaller contusion lesions and decreased accumulation of inflammatory macrophages. Collectively, these data indicate that miR-155 is a novel therapeutic target capable of simultaneously overcoming neuron-intrinsic and neuron-extrinsic barriers to repair after SCI. Axon regeneration after spinal cord injury (SCI) fails due to neuron

  8. Transcriptional regulation of gene expression clusters in motor neurons following spinal cord injury

    DEFF Research Database (Denmark)

    Ryge, J.; Winther, Ole; Wienecke, J.

    2010-01-01

    Background: Spinal cord injury leads to neurological dysfunctions affecting the motor, sensory as well as the autonomic systems. Increased excitability of motor neurons has been implicated in injury-induced spasticity, where the reappearance of self-sustained plateau potentials in the absence...... of modulatory inputs from the brain correlates with the development of spasticity. Results: Here we examine the dynamic transcriptional response of motor neurons to spinal cord injury as it evolves over time to unravel common gene expression patterns and their underlying regulatory mechanisms. For this we use...... a rat-tail-model with complete spinal cord transection causing injury-induced spasticity, where gene expression profiles are obtained from labeled motor neurons extracted with laser microdissection 0, 2, 7, 21 and 60 days post injury. Consensus clustering identifies 12 gene clusters with distinct time...

  9. Dendritic spine dysgenesis in superficial dorsal horn sensory neurons after spinal cord injury.

    Science.gov (United States)

    Cao, Xiaoyu C; Pappalardo, Laura W; Waxman, Stephen G; Tan, Andrew M

    2017-01-01

    Neuropathic pain is a major complication of spinal cord injury, and despite aggressive efforts, this type of pain is refractory to available clinical treatment. Our previous work has demonstrated a structure-function link between dendritic spine dysgenesis on nociceptive sensory neurons in the intermediate zone, laminae IV/V, and chronic pain in central nervous system and peripheral nervous system injury models of neuropathic pain. To extend these findings, we performed a follow-up structural analysis to assess whether dendritic spine remodeling occurs on superficial dorsal horn neurons located in lamina II after spinal cord injury. Lamina II neurons are responsible for relaying deep, delocalized, often thermally associated pain commonly experienced in spinal cord injury pathologies. We analyzed dendritic spine morphometry and localization in tissue obtained from adult rats exhibiting neuropathic pain one-month following spinal cord injury. Although the total density of dendritic spines on lamina II neurons did not change after spinal cord injury, we observed an inverse relationship between the densities of thin- and mushroom-shaped spines: thin-spine density decreased while mushroom-spine density increased. These structural changes were specifically noted along dendritic branches within 150 µm from the soma, suggesting a possible adverse contribution to nociceptive circuit function. Intrathecal treatment with NSC23766, a Rac1-GTPase inhibitor, significantly reduced spinal cord injury-induced changes in both thin- and mushroom-shaped dendritic spines. Overall, these observations demonstrate that dendritic spine remodeling occurs in lamina II, regulated in part by the Rac1-signaling pathway, and suggests that structural abnormalities in this spinal cord region may also contribute to abnormal nociception after spinal cord injury.

  10. Retrograde tracing of zinc-enriched (ZEN) neuronal somata in rat spinal cord

    DEFF Research Database (Denmark)

    Wang, Zhanyou; Danscher, G; Mook Jo, S

    2001-01-01

    The zinc selenide autometallographic (ZnSeAMG) technique for tracing the retrograde axonal transport of zinc ions in zinc-enriched (ZEN) neurons was used to map the distribution of ZEN neuronal somata in rat spinal cord. After a local injection of sodium selenide into the dorsal or ventral horn, Zn...... neurons have relatively short axons or boutons en passage close to the neuronal origin. Ultrastructurally, the retrogradely transported zinc selenide clusters were found in the lysosomes of ZEN somata and proximal dendrites. Electron microscopic studies also revealed two different kinds of ZEN terminals...

  11. Neuronal sFlt1 and Vegfaa determine venous sprouting and spinal cord vascularization

    DEFF Research Database (Denmark)

    Wild, Raphael; Klems, Alina; Takamiya, Masanari

    2017-01-01

    Formation of organ-specific vasculatures requires cross-talk between developing tissue and specialized endothelial cells. Here we show how developing zebrafish spinal cord neurons coordinate vessel growth through balancing of neuron-derived Vegfaa, with neuronal sFlt1 restricting Vegfaa......-Kdrl mediated angiogenesis at the neurovascular interface. Neuron-specific loss of flt1 or increased neuronal vegfaa expression promotes angiogenesis and peri-neural tube vascular network formation. Combining loss of neuronal flt1 with gain of vegfaa promotes sprout invasion into the neural tube. On loss...... of neuronal flt1, ectopic sprouts emanate from veins involving special angiogenic cell behaviours including nuclear positioning and a molecular signature distinct from primary arterial or secondary venous sprouting. Manipulation of arteriovenous identity or Notch signalling established that ectopic sprouting...

  12. Spinal muscular atrophy: Selective motor neuron loss and global defect in the assembly of ribonucleoproteins.

    Science.gov (United States)

    Beattie, Christine E; Kolb, Stephen J

    2018-02-17

    Spinal muscular atrophy is caused by deletions or mutations in the SMN1 gene that result in reduced expression of the SMN protein. The SMN protein is an essential molecular chaperone that is required for the biogenesis of multiple ribonucleoprotein (RNP) complexes including spliceosomal small nuclear RNPs (snRNPs). Reductions in SMN expression result in a reduced abundance of snRNPs and to downstream RNA splicing alterations. SMN is also present in axons and dendrites and appears to have important roles in the formation of neuronal mRNA-protein complexes during development or neuronal repair. Thus, SMA is an exemplar, selective motor neuron disorder that is caused by defects in fundamental RNA processing events. A detailed molecular understanding of how motor neurons fail, and why other neurons do not, in SMA will yield important principals about motor neuron maintenance and neuronal specificity in neurodegenerative diseases. Copyright © 2018. Published by Elsevier B.V.

  13. Co-ultramicronized palmitoylethanolamide/luteolin promotes neuronal regeneration after spinal cord injury

    Directory of Open Access Journals (Sweden)

    Rosalia eCrupi

    2016-03-01

    Full Text Available Spinal cord injury (SCI stimulates activation of astrocytes and infiltration of immune cells at the lesion site; however, the mechanism that promotes the birth of new neurons is still under debate. Neuronal regeneration is restricted after spinal cord injury, but can be stimulated by experimental intervention. Previously we demonstrated that treatment co-ultramicronized palmitoylethanolamide and luteolin, namely co-ultraPEALut, reduced inflammation. The present study was designed to explore the neuroregenerative properties of co-ultra PEALut in an estabished murine model of SCI. A vascular clip was applied to the spinal cord dura at T5 to T8 to provoke injury. Mice were treated with co-ultraPEALut (1 mg/kg, intraperitoneally daily for 72 h after SCI. Co-ultraPEALut increased the numbers of both bromodeoxyuridine-positive nuclei and doublecortin-immunoreactive cells in the spinal cord of injured mice. To correlate neuronal development with synaptic plasticity a Golgi method was employed to analyze dendritic spine density. Co-ultraPEALut administration stimulated expression of the neurotrophic factors brain-derived neurotrophic factor, glial cell-derived neurotrophic factor, nerve growth factor and neurotrophin-3. These findings show a prominent effect of co-ultraPEALut administration in the management of survival and differentiation of new neurons and spine maturation, and may represent a therapeutic treatment for spinal cord and other traumatic diseases.

  14. Selective retrograde transport of D-aspartate in spinal interneurons anc cortical neurons of rats

    International Nuclear Information System (INIS)

    Rustioni, A.; Cuenod, M.

    1982-01-01

    Retrograde labeling of neuronal elements in the brain and spinal cord has been investigated by autoradiographic techniques following injections of D-[ 3 H]aspartate (asp), [ 3 H]γ-aminobutyric acid (GABA) or horseradish peroxidase (HRP) in the medulla and spinal cord of rats. Twenty-four hours after D-[ 3 H]asp injections focused upon the cuneate nucleus, autoradiographic labeling is present over fibers in the pyramidal tract, internal capsule and over layer V pyramids in the forelimb representation of the sensorimotor cortex. After [ 3 H]GABA injections in the same nucleus no labeling attributable to retrograde translocation can be detected in spinal segments, brain stem or cortex. Conversely, injections of 30% HRP in the cuneate nucleus label neurons in several brain stem nuclei, in spinal gray and in layer V of the sensorimotor cortex. D-[ 3 H]Asp injections focused on the dorsal horn at cervical segments label a fraction of perikarya of the substantia gelatinosa and a sparser population of larger neurons in laminae IV to VI for a distance of 3-5 segments above and below the injection point. No brain stem neuronal perikarya appear labeled following spinal injections of D-[ 3 H]asp although autoradiographic grains overlie pyramidal tract fibers on the side contralateral to the injection. (Auth.)

  15. Stereological estimate of the total number of neurons in spinal segment D9 of the red-eared turtle

    DEFF Research Database (Denmark)

    Walløe, Solveig; Nissen, Ulla Vig; Berg, Rune W

    2011-01-01

    The red-eared turtle is an important animal model for investigating the neural activity in the spinal circuit that generates motor behavior. However, basic anatomical features, including the number of neurons in the spinal segments involved, are unknown. In the present study, we estimate the total...... number of neurons in segment D9 of the spinal cord in the red-eared turtle (Trachemys scripta elegans) using stereological cell counting methods. In transverse spinal cord sections stained with modified Giemsa, motoneurons (MNs), interneurons (INs), and non-neuronal cells were distinguished according...

  16. Neurogenic period of ascending tract neurons in the upper lumbar spinal cord of the rat

    International Nuclear Information System (INIS)

    Nandi, K.N.; Beal, J.A.; Knight, D.S.

    1990-01-01

    Although the neurogenic period for neurons in the lumbar spinal cord has been clearly established (Days 12 through 16 of gestation), it is not known when the neurogenesis of ascending tract neurons is completed within this period. The purpose of the present study was to determine the duration of the neurogenic period for projection neurons of the ascending tracts. To label neurons undergoing mitosis during this period, tritiated thymidine was administered to fetal rats on Embryonic (E) Days E13 through E16 of gestation. Ascending tract neurons of the lumbar cord were later (Postnatal Days 40-50) labeled in each animal with a retrograde tracer, Fluoro-Gold, applied at the site of a hemisection at spinal cord segment C3. Ascending tract neurons which were undergoing mitosis in the upper lumbar cord were double labeled, i.e., labeled with both tritiated thymidine and Fluoro-Gold. On Day E13, 89-92% of the ascending tract neurons were double labeled; on Day E14, 35-37%; and on Day E15, 1-4%. Results showed, then, that some ascending tract neurons were double labeled through Day E15 and were, therefore, proliferating in the final one-third of the neurogenic period. Ascending tract neurons proliferating on Day E15 were confined to laminae III, IV, V, and X and the nucleus dorsalis. Long tract neurons in the superficial dorsal horn (laminae I and II), on the other hand, were found to have completed neurogenesis on Day E14 of gestation. Results of the present study show that spinal neurogenesis of ascending projection neurons continues throughout most of the neurogenic period and does not completely follow the well-established ventral to dorsal gradient

  17. Systematic administration of B vitamins attenuates neuropathic hyperalgesia and reduces spinal neuron injury following temporary spinal cord ischaemia in rats.

    Science.gov (United States)

    Yu, C-Z; Liu, Y-P; Liu, S; Yan, M; Hu, S-J; Song, X-J

    2014-01-01

    B vitamins have been demonstrated to be effective in treating chronic pain due to peripheral nerve injury. We investigated whether B vitamins could alleviate neuropathic pain and reduce neuron injury following temporary ischaemia in a rat model of spinal cord ischaemia-reperfusion injury (SCII). SCII was produced by transiently blocking the unilateral lumbar arteries in adult male Sprague-Dawley rats. Behavioural and neurochemical signs of neuropathic pain and spinal neuron injury were analysed with and without B vitamin treatment. SCII caused behavioural thermal hyperalgesia and mechanical allodynia and neurochemical alterations, including increased expression of the vanilloid receptor 1 (VR1) and induction of c-Fos, as well as activation of the astrocytes and microglial cells in the spinal cord. Repetitive systemic administration of vitamin B complex (B1/B6/B12 at 33/33/0.5 mg/kg, i.p., daily, for 7-14 consecutive days) significantly reduced thermal hyperalgesia and the increased expression of VR1 and c-Fos, as well as activation of the astrocytes and microglial cells. SCII caused a dramatic decrease of the expression of the rate-limiting enzyme glutamic acid decarboxylase-65 (GAD65), which synthesizes γ-aminobutyric acid (GABA) in the axonal terminals, and β-III-tubulin, and also caused loss of Nissl bodies in the spinal cord. These alterations were largely prevented and rescued by the B vitamin treatment. These findings support the idea that the B vitamins are capable of neuroprotection and antinociception during spinal cord injury due to temporary ischaemia. Rescuing the loss of inhibitory GABAergic tone may reduce spinal central sensitization and contribute to B vitamin-induced analgesia. © 2013 European Pain Federation - EFIC®

  18. Bone marrow mesenchymal stem cells decrease CHOP expression and neuronal apoptosis after spinal cord injury.

    Science.gov (United States)

    Gu, Chuanlong; Li, Heyangzi; Wang, Chao; Song, Xinghui; Ding, Yuemin; Zheng, Mingzhi; Liu, Wei; Chen, Yingying; Zhang, Xiaoming; Wang, Linlin

    2017-01-01

    Spinal cord injury (SCI) leads to irreversible neuronal loss and ultimately leads to paralysis. Bone marrow derived mesenchymal stem cells (BMSCs) have been demonstrated to be an effective approach to treat SCI. The present study was designed to investigate the role of BMSCs in rats with spinal cord injury and in oxygen-glucose deprivation (OGD) treated motor neurons. The results demonstrated that BMSCs could improve locomotor function and decrease expression of pro-apoptotic transcription factor C/EBP homologous protein (CHOP) and apoptosis after SCI. Furthermore, co-culture with BMSCs or conditioned medium from BMSCs could also decrease the expression of CHOP and apoptosis in post-OGD motor neurons, supporting that BMSCs exerts protective effects by decreasing the expression of CHOP in injured motor neurons. Our findings provide a potential novel mechanism for BMSCs treatments in patients with SCI. Copyright © 2016. Published by Elsevier Ireland Ltd.

  19. Crosstalk between p38, Hsp25 and Akt in spinal motor neurons after sciatic nerve injury

    Science.gov (United States)

    Murashov, A. K.; Ul Haq, I.; Hill, C.; Park, E.; Smith, M.; Wang, X.; Wang, X.; Goldberg, D. J.; Wolgemuth, D. J.

    2001-01-01

    The p38 stress-activated protein kinase pathway is involved in regulation of phosphorylation of Hsp25, which in turn regulates actin filament dynamic in non-neuronal cells. We report that p38, Hsp25 and Akt signaling pathways were specifically activated in spinal motor neurons after sciatic nerve axotomy. The activation of the p38 kinase was required for induction of Hsp25 expression. Furthermore, Hsp25 formed a complex with Akt, a member of PI-3 kinase pathway that prevents neuronal cell death. Together, our observations implicate Hsp25 as a central player in a complex system of signaling that may both promote regeneration of nerve fibers and prevent neuronal cell death in the injured spinal cord.

  20. Neural progenitor cells but not astrocytes respond distally to thoracic spinal cord injury in rat models

    Directory of Open Access Journals (Sweden)

    Tara Nguyen

    2017-01-01

    Full Text Available Traumatic spinal cord injury (SCI is a detrimental condition that causes loss of sensory and motor function in an individual. Many complex secondary injury cascades occur after SCI and they offer great potential for therapeutic targeting. In this study, we investigated the response of endogenous neural progenitor cells, astrocytes, and microglia to a localized thoracic SCI throughout the neuroaxis. Twenty-five adult female Sprague-Dawley rats underwent mild-contusion thoracic SCI (n = 9, sham surgery (n = 8, or no surgery (n = 8. Spinal cord and brain tissues were fixed and cut at six regions of the neuroaxis. Immunohistochemistry showed increased reactivity of neural progenitor cell marker nestin in the central canal at all levels of the spinal cord. Increased reactivity of astrocyte-specific marker glial fibrillary acidic protein was found only at the lesion epicenter. The number of activated microglia was significantly increased at the lesion site, and activated microglia extended to the lumbar enlargement. Phagocytic microglia and macrophages were significantly increased only at the lesion site. There were no changes in nestin, glial fibrillary acidic protein, microglia and macrophage response in the third ventricle of rats subjected to mild-contusion thoracic SCI compared to the sham surgery or no surgery. These findings indicate that neural progenitor cells, astrocytes and microglia respond differently to a localized SCI, presumably due to differences in inflammatory signaling. These different cellular responses may have implications in the way that neural progenitor cells can be manipulated for neuroregeneration after SCI. This needs to be further investigated.

  1. Responses of spinal dorsal horn neurons to foot movements in rats with a sprained ankle

    OpenAIRE

    Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon; Chung, Jin Mo

    2011-01-01

    Acute ankle injuries are common problems and often lead to persistent pain. To investigate the underlying mechanism of ankle sprain pain, the response properties of spinal dorsal horn neurons were examined after ankle sprain. Acute ankle sprain was induced manually by overextending the ankle of a rat hindlimb in a direction of plantarflexion and inversion. The weight-bearing ratio (WBR) of the affected foot was used as an indicator of pain. Single unit activities of dorsal horn neurons in res...

  2. Olfaction in the Queensland fruit fly, Bactrocera tryoni. I: Identification of olfactory receptor neuron types responding to environmental odors.

    Science.gov (United States)

    Hull, C D; Cribb, B W

    2001-05-01

    The electroantennogram method was used to investigate the number of distinct olfactory receptor neuron types responding to a range of behaviorally active volatile chemicals in gravid Queensland fruit flies, Bactrocera tryoni. Three receptor neuron types were identified. One type responds to methyl butyrate, 2-butanone, farnesene, and carbon dioxide; a second to ethanol; and a third to n-butyric acid and ammonia. The receptor neuron type responding to methyl butyrate, 2-butanone, farnesene, and carbon dioxide consists of three subtypes. The presence of a limited number of receptor neuron types responding to a diverse set of chemicals and the reception of carbon dioxide by a receptor neuron type that responds to other odorants are novel aspects of the peripheral olfactory discrimination process.

  3. Converging Mechanisms of p53 Activation Drive Motor Neuron Degeneration in Spinal Muscular Atrophy.

    Science.gov (United States)

    Simon, Christian M; Dai, Ya; Van Alstyne, Meaghan; Koutsioumpa, Charalampia; Pagiazitis, John G; Chalif, Joshua I; Wang, Xiaojian; Rabinowitz, Joseph E; Henderson, Christopher E; Pellizzoni, Livio; Mentis, George Z

    2017-12-26

    The hallmark of spinal muscular atrophy (SMA), an inherited disease caused by ubiquitous deficiency in the SMN protein, is the selective degeneration of subsets of spinal motor neurons. Here, we show that cell-autonomous activation of p53 occurs in vulnerable but not resistant motor neurons of SMA mice at pre-symptomatic stages. Moreover, pharmacological or genetic inhibition of p53 prevents motor neuron death, demonstrating that induction of p53 signaling drives neurodegeneration. At late disease stages, however, nuclear accumulation of p53 extends to resistant motor neurons and spinal interneurons but is not associated with cell death. Importantly, we identify phosphorylation of serine 18 as a specific post-translational modification of p53 that exclusively marks vulnerable SMA motor neurons and provide evidence that amino-terminal phosphorylation of p53 is required for the neurodegenerative process. Our findings indicate that distinct events induced by SMN deficiency converge on p53 to trigger selective death of vulnerable SMA motor neurons. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  4. Origin of heterogeneous spiking patterns from continuously distributed ion channel densities: a computational study in spinal dorsal horn neurons.

    Science.gov (United States)

    Balachandar, Arjun; Prescott, Steven A

    2018-01-20

    Distinct spiking patterns may arise from qualitative differences in ion channel expression (i.e. when different neurons express distinct ion channels) and/or when quantitative differences in expression levels qualitatively alter the spike generation process. We hypothesized that spiking patterns in neurons of the superficial dorsal horn (SDH) of spinal cord reflect both mechanisms. We reproduced SDH neuron spiking patterns by varying densities of K V 1- and A-type potassium conductances. Plotting the spiking patterns that emerge from different density combinations revealed spiking-pattern regions separated by boundaries (bifurcations). This map suggests that certain spiking pattern combinations occur when the distribution of potassium channel densities straddle boundaries, whereas other spiking patterns reflect distinct patterns of ion channel expression. The former mechanism may explain why certain spiking patterns co-occur in genetically identified neuron types. We also present algorithms to predict spiking pattern proportions from ion channel density distributions, and vice versa. Neurons are often classified by spiking pattern. Yet, some neurons exhibit distinct patterns under subtly different test conditions, which suggests that they operate near an abrupt transition, or bifurcation. A set of such neurons may exhibit heterogeneous spiking patterns not because of qualitative differences in which ion channels they express, but rather because quantitative differences in expression levels cause neurons to operate on opposite sides of a bifurcation. Neurons in the spinal dorsal horn, for example, respond to somatic current injection with patterns that include tonic, single, gap, delayed and reluctant spiking. It is unclear whether these patterns reflect five cell populations (defined by distinct ion channel expression patterns), heterogeneity within a single population, or some combination thereof. We reproduced all five spiking patterns in a computational model by

  5. Neuronal plasticity after a human spinal cord injury: positive and negative effects.

    Science.gov (United States)

    Dietz, Volker

    2012-05-01

    In patients suffering an incomplete spinal cord injury (SCI) an improvement in walking function can be achieved by providing a functional training with an appropriate afferent input. In contrast, in immobilized incomplete and complete subjects a negative neuroplasticity leads to a neuronal dysfunction. After an SCI, neuronal centers below the level of lesion exhibit plasticity that either can be exploited by specific training paradigms or undergo a degradation of function due to the loss of appropriate input. Load- and hip-joint-related afferent inputs seem to be of crucial importance for the generation of a locomotor pattern and, consequently, the effectiveness of the locomotor training. In severely affected SCI subjects rehabilitation robots allow for a longer and more intensive training and can provide feedback information. Conversely, in severely affected chronic SCI individuals without functional training the locomotor activity in the leg muscles exhausts rapidly during assisted locomotion. This is accompanied by a shift from early to dominant late spinal reflex components. The exhaustion of locomotor activity is also observed in non-ambulatory patients with an incomplete SCI. It is assumed that in chronic SCI the patient's immobility results in a reduced input from supraspinal and peripheral sources and leads to a dominance of inhibitory drive within spinal neuronal circuitries underlying locomotor pattern and spinal reflex generation. A training with an enhancement of an appropriate proprioceptive input early after an SCI might serve as an intervention to prevent neuronal dysfunction. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Monosynaptic connections between primary afferents and giant neurons in the turtle spinal dorsal horn

    DEFF Research Database (Denmark)

    Fernández, A; Radmilovich, M; Russo, R E

    1996-01-01

    This paper reports the occurrence of monosynaptic connections between dorsal root afferents and a distinct cell type-the giant neuron-deep in the dorsal horn of the turtle spinal cord. Light microscope studies combining Nissl stain and transganglionic HRP-labeling of the primary afferents have...... revealed the occurrence of axosomatic and axodendritic contacts between labeled boutons and giant neurons. The synaptic nature of these contacts has been confirmed by use of electron microscope procedures involving the partial three-dimensional reconstruction of identified giant neurons. Intracellular...

  7. Visual patch clamp recording of neurons in thick portions of the adult spinal cord

    DEFF Research Database (Denmark)

    Munch, Anders Sonne; Smith, Morten; Moldovan, Mihai

    2010-01-01

    The study of visually identified neurons in slice preparations from the central nervous system offers considerable advantages over in vivo preparations including high mechanical stability in the absence of anaesthesia and full control of the extracellular medium. However, because of their relative...... enlargement of the spinal cord. With a conventional upright microscope in which the light condenser was carefully adjusted, we could visualize neurons present at the surface of the slice and record them with the whole-cell patch clamp technique. We show that neurons present in the middle of the preparation...

  8. Massively Parallel Single Nucleus Transcriptional Profiling Defines Spinal Cord Neurons and Their Activity during Behavior

    Directory of Open Access Journals (Sweden)

    Anupama Sathyamurthy

    2018-02-01

    Full Text Available To understand the cellular basis of behavior, it is necessary to know the cell types that exist in the nervous system and their contributions to function. Spinal networks are essential for sensory processing and motor behavior and provide a powerful system for identifying the cellular correlates of behavior. Here, we used massively parallel single nucleus RNA sequencing (snRNA-seq to create an atlas of the adult mouse lumbar spinal cord. We identified and molecularly characterized 43 neuronal populations. Next, we leveraged the snRNA-seq approach to provide unbiased identification of neuronal populations that were active following a sensory and a motor behavior, using a transcriptional signature of neuronal activity. This approach can be used in the future to link single nucleus gene expression data with dynamic biological responses to behavior, injury, and disease.

  9. Massively Parallel Single Nucleus Transcriptional Profiling Defines Spinal Cord Neurons and Their Activity during Behavior.

    Science.gov (United States)

    Sathyamurthy, Anupama; Johnson, Kory R; Matson, Kaya J E; Dobrott, Courtney I; Li, Li; Ryba, Anna R; Bergman, Tzipporah B; Kelly, Michael C; Kelley, Matthew W; Levine, Ariel J

    2018-02-20

    To understand the cellular basis of behavior, it is necessary to know the cell types that exist in the nervous system and their contributions to function. Spinal networks are essential for sensory processing and motor behavior and provide a powerful system for identifying the cellular correlates of behavior. Here, we used massively parallel single nucleus RNA sequencing (snRNA-seq) to create an atlas of the adult mouse lumbar spinal cord. We identified and molecularly characterized 43 neuronal populations. Next, we leveraged the snRNA-seq approach to provide unbiased identification of neuronal populations that were active following a sensory and a motor behavior, using a transcriptional signature of neuronal activity. This approach can be used in the future to link single nucleus gene expression data with dynamic biological responses to behavior, injury, and disease. Published by Elsevier Inc.

  10. Monosynaptic connections between primary afferents and giant neurons in the turtle spinal dorsal horn

    DEFF Research Database (Denmark)

    Fernández, A; Radmilovich, M; Russo, R E

    1996-01-01

    This paper reports the occurrence of monosynaptic connections between dorsal root afferents and a distinct cell type-the giant neuron-deep in the dorsal horn of the turtle spinal cord. Light microscope studies combining Nissl stain and transganglionic HRP-labeling of the primary afferents have...... recording in spinal cord slices provided functional evidence indicating the monosynaptic connections between dorsal root afferents and giant neurons. The recorded neurons were morphologically identified by means of biocytin injection and with avidin conjugates. Electrical stimulation of the ipsilateral...... dorsal roots evoked synaptic responses with short, fixed latencies (1.6-5.6 ms), which remained unchanged at high frequencies (10 Hz). Excitatory polysynaptic potentials were also observed. By means of pharmacological procedures the short-latency response was dissected in two components: one insensitive...

  11. Dendritic spine remodeling after spinal cord injury alters neuronal signal processing.

    Science.gov (United States)

    Tan, Andrew M; Choi, Jin-Sung; Waxman, Stephen G; Hains, Bryan C

    2009-10-01

    Central sensitization, a prolonged hyperexcitability of dorsal horn nociceptive neurons, is a major contributor to abnormal pain processing after spinal cord injury (SCI). Dendritic spines are micron-sized dendrite protrusions that can regulate the efficacy of synaptic transmission. Here we used a computational approach to study whether changes in dendritic spine shape, density, and distribution can individually, or in combination, adversely modify the input-output function of a postsynaptic neuron to create a hyperexcitable neuronal state. The results demonstrate that a conversion from thin-shaped to more mature, mushroom-shaped spine structures results in enhanced synaptic transmission and fidelity, improved frequency-following ability, and reduced inhibitory gating effectiveness. Increasing the density and redistributing spines toward the soma results in a greater probability of action potential activation. Our results demonstrate that changes in dendritic spine morphology, documented in previous studies on spinal cord injury, contribute to the generation of pain following SCI.

  12. Gustatory receptor neuron responds to DEET and other insect repellents in the yellow-fever mosquito, Aedes aegypti

    Science.gov (United States)

    Sanford, Jillian L.; Shields, Vonnie D. C.; Dickens, Joseph C.

    2013-03-01

    Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow-fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as N, N-diethyl-3-methylbenzamide and other insect repellents. Two other neurons with differing spikes responded to salt (NaCl) and sucrose. This is the first report of a gustatory receptor neuron specific for insect repellents in mosquitoes and may provide a tool for screening chemicals to discover novel or improved feeding deterrents and repellents for use in the management of arthropod disease vectors.

  13. Tuning the network: modulation of neuronal microcircuits in the spinal cord and hippocampus.

    Science.gov (United States)

    LeBeau, Fiona E N; El Manira, Abdeljabbar; Griller, Sten

    2005-10-01

    Adaptation of an organism to its changing environment ultimately depends on the modification of neuronal activity. The dynamic interaction between cellular components within neuronal networks relies on fast synaptic interaction via ionotropic receptors. However, neuronal networks are also subject to modulation mediated by various metabotropic G-protein-coupled receptors that modify synaptic and neuronal function. Modulation increases the functional complexity of a network, because the same cellular components can produce different outputs depending on the behavioural state of the animal. This review, which is part of the TINS Microcircuits Special Feature, provides an overview of neuromodulation in two neuronal circuits that both produce oscillatory activity but differ fundamentally in function. Hippocampal circuits are compared with the spinal networks generating locomotion, with a view to exploring common principles of neuromodulatory activity.

  14. Gene expression profiling of two distinct neuronal populations in the rodent spinal cord

    DEFF Research Database (Denmark)

    Ryge, Jesper; Westerdahl, Ann Charlotte; Alstøm, Preben

    2008-01-01

    populations can in combination with global gene expression profiling potentially increase the resolution and specificity of such studies to shed new light on neuronal functions at the cellular level. Methodology/Principal Findings: We examine the microarray gene expression profiles of two distinct neuronal...... populations in the spinal cord of the neonatal rat, the principal motor neurons and specific interneurons involved in motor control. The gene expression profiles of the respective cell populations were obtained from amplified mRNA originating from 50-250 fluorescently identified and laser microdissected cells...... associated with this neuronal population. As a validation of our method we find 17 genes to be more expressed in the motor neurons than in the interneurons and of these only one had not previously been described in this population. Conclusions/Significance: We provide an optimized experimental protocol...

  15. Nuclear calcium signaling in spinal neurons drives a genomic program required for persistent inflammatory pain.

    Science.gov (United States)

    Simonetti, Manuela; Hagenston, Anna M; Vardeh, Daniel; Freitag, H Eckehard; Mauceri, Daniela; Lu, Jianning; Satagopam, Venkata P; Schneider, Reinhard; Costigan, Michael; Bading, Hilmar; Kuner, Rohini

    2013-01-09

    Persistent pain induced by noxious stimuli is characterized by the transition from normosensitivity to hypersensitivity. Underlying mechanisms are not well understood, although gene expression is considered important. Here, we show that persistent nociceptive-like activity triggers calcium transients in neuronal nuclei within the superficial spinal dorsal horn, and that nuclear calcium is necessary for the development of long-term inflammatory hypersensitivity. Using a nucleus-specific calcium signal perturbation strategy in vivo complemented by gene profiling, bioinformatics, and functional analyses, we discovered a pain-associated, nuclear calcium-regulated gene program in spinal excitatory neurons. This includes C1q, a modulator of synaptic spine morphogenesis, which we found to contribute to activity-dependent spine remodelling on spinal neurons in a manner functionally associated with inflammatory hypersensitivity. Thus, nuclear calcium integrates synapse-to-nucleus communication following noxious stimulation and controls a spinal genomic response that mediates the transition between acute and long-term nociceptive sensitization by modulating functional and structural plasticity. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. ASIC channel inhibition enhances excitotoxic neuronal death in an in vitro model of spinal cord injury.

    Science.gov (United States)

    Mazzone, Graciela L; Veeraraghavan, Priyadharishini; Gonzalez-Inchauspe, Carlota; Nistri, Andrea; Uchitel, Osvaldo D

    2017-02-20

    In the spinal cord high extracellular glutamate evokes excitotoxic damage with neuronal loss and severe locomotor impairment. During the cell dysfunction process, extracellular pH becomes acid and may activate acid-sensing ion channels (ASICs) which could be important contributors to neurodegenerative pathologies. Our previous studies have shown that transient application of the glutamate analog kainate (KA) evokes delayed excitotoxic death of spinal neurons, while white matter is mainly spared. The present goal was to enquire if ASIC channels modulated KA damage in relation to locomotor network function and cell death. Mouse spinal cord slices were treated with KA (0.01 or 0.1mM) for 1h, and then washed out for 24h prior to analysis. RT-PCR results showed that KA (at 0.01mM concentration that is near-threshold for damage) increased mRNA expression of ASIC1a, ASIC1b, ASIC2 and ASIC3, an effect reversed by the ASIC inhibitor 4',6-diamidino-2-phenylindole (DAPI). A KA neurotoxic dose (0.1mM) reduced ASIC1a and ASIC2 expression. Cell viability assays demonstrated KA-induced large damage in spinal slices from mice with ASIC1a gene ablation. Likewise, immunohistochemistry indicated significant neuronal loss when KA was followed by the ASIC inhibitors DAPI or amiloride. Electrophysiological recording from ventral roots of isolated spinal cords showed that alternating oscillatory cycles were slowed down by 0.01mMKA, and intensely inhibited by subsequently applied DAPI or amiloride. Our data suggest that early rise in ASIC expression and function counteracted deleterious effects on spinal networks by raising the excitotoxicity threshold, a result with potential implications for improving neuroprotection. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Histochemical characterization, distribution and morphometric analysis of NADPH diaphorase neurons in the spinal cord of the agouti

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    Marco Aurelio M Freire

    2008-05-01

    Full Text Available We evaluated the neuropil distribution of the enzymes NADPH diaphorase (NADPH-d and cytochrome oxidase (CO in the spinal cord of the agouti, a medium-sized diurnal rodent, together with the distribution pattern and morphometrical characteristics of NADPH-d reactive neurons across different spinal segments. Neuropil labeling pattern was remarkably similar for both enzymes in coronal sections: reactivity was higher in regions involved with pain processing. We found two distinct types of NADPH-d reactive neurons in the agouti’s spinal cord: type I neurons had large, heavily stained cell bodies while type II neurons displayed relatively small and poorly stained somata. We concentrated our analysis on type I neurons. These were found mainly in the dorsal horn and around the central canal of every spinal segment, with a few scattered neurons located in the ventral horn of both cervical and lumbar regions. Overall, type I neurons were more numerous in the cervical region. Type I neurons were also found in the white matter, particularly in the ventral funiculum. Morphometrical analysis revealed that type I neurons located in the cervical region have dendritic trees that are more complex than those located in both lumbar and thoracic regions. In addition, NADPH-d cells located in the ventral horn had a larger cell body, especially in lumbar segments. The resulting pattern of cell body and neuropil distribution is in accordance with proposed schemes of segregation of function in the mammalian spinal cord.

  18. Upregulation of GLT-1 by treatment with ceftriaxone alleviates radicular pain by reducing spinal astrocyte activation and neuronal hyperexcitability.

    Science.gov (United States)

    Nicholson, K J; Gilliland, T M; Winkelstein, B A

    2014-01-01

    Cervical nerve root injury commonly leads to radicular pain. Normal sensation relies on regulation of extracellular glutamate in the spinal cord by glutamate transporters. The goal of this study was to define the temporal response of spinal glutamate transporters (glial glutamate transporter 1 [GLT-1], glutamate-aspartate transporter [GLAST], and excitatory amino acid carrier 1) following nerve root compressions that do or do not produce sensitivity in the rat and to evaluate the role of glutamate uptake in radicular pain by using ceftriaxone to upregulate GLT-1. Compression was applied to the C7 nerve root. Spinal glutamate transporter expression was evaluated at days 1 and 7. In a separate study, rats underwent a painful root compression and were treated with ceftriaxone or the vehicle saline. Glial glutamate transporter expression, astrocytic activation (glial fibrillary acidic protein [GFAP]), and neuronal excitability were assessed at day 7. Both studies measured behavioral sensitivity for 7 days after injury. Spinal GLT-1 significantly decreased (P ceftriaxone treatment (day 2), mechanical allodynia began to decrease; both mechanical allodynia and thermal hyperalgesia were attenuated (P Ceftriaxone also reduced (P < 0.024) spinal GFAP and GLAST expression, and neuronal hyperexcitability in the spinal dorsal horn, restoring the proportion of spinal neurons classified as wide dynamic range to that of normal. These findings suggest that nerve root-mediated pain is maintained jointly by spinal astrocytic reactivity and neuronal hyperexcitability and that these spinal modifications are associated with reduced glutamate uptake by GLT-1. Copyright © 2013 Wiley Periodicals, Inc.

  19. Concentrations of trace minerals in the spinal cord of horses with equine motor neuron disease.

    Science.gov (United States)

    Polack, E W; King, J M; Cummings, J F; Mohammed, H O; Birch, M; Cronin, T

    2000-06-01

    To compare concentrations of trace minerals in the spinal cord of horses with equine motor neuron disease (EMND) with those of horses without neurologic disease (control horses). 24 horses with EMND and 22 control horses. Spinal cord trace mineral concentrations in horses with EMND and control horses were analyzed by use of inductively coupled plasma atomic emission spectroscopy (calcium, phosphorus, sodium, potassium, magnesium, copper, iron, manganese, nickel, zinc, aluminum, cobalt, and chromium), atomic absorption spectrophotometry (lead and cadmium), flameless atomic absorption (mercury), and fluorometry (selenium). Copper concentration was significantly higher in the spinal cord of horses with EMND, compared with control horses; spinal cord concentrations of all other trace minerals were similar between groups. Among spinal cord trace minerals investigated in the study, only copper concentrations were significantly different between horses with EMND and horses without neurologic disease, which suggests that copper may be involved in the pathogenesis of EMND. An hypothesis of oxidative injury in this disease is supported by the finding of increased copper concentrations in the spinal cord and by low vitamin E concentrations reported by other researchers.

  20. Recovery of neuronal and network excitability after spinal cord injury and implications for spasticity

    Directory of Open Access Journals (Sweden)

    Jessica Maria D'Amico

    2014-05-01

    Full Text Available The state of areflexia and muscle weakness that immediately follows a spinal cord injury is gradually replaced by the recovery of neuronal and network excitability, leading to both improvements in residual motor function and the development of spasticity. In this review we summarize recent animal and human studies that describe how motoneurons and their activation by sensory pathways become hyperexcitable to compensate for the reduction of descending and movement-induced sensory inputs and the eventual impact on the muscle. We discuss how replacing lost patterned activation of the spinal cord by activating synaptic inputs via assisted movements, pharmacology or electrical stimulation may help to recover lost spinal inhibition. This may lead to a reduction of uncontrolled activation of the spinal cord and thus, improve its controlled activation by synaptic inputs to ultimately normalize circuit function. Increasing the excitation of the spinal cord below an injury with spared descending and/or peripheral functional synaptic activation, instead of suppressing it pharmacologically, may provide the best avenue to improve residual motor function and manage spasticity after spinal cord injury.

  1. Gustatory receptor neuron responds to DEET and other insect repellents in the yellow fever mosquito, aedes aegypti

    Science.gov (United States)

    Three gustatory receptor neurons were characterized for contact chemoreceptive sensilla on the labella of female yellow fever mosquitoes, Aedes aegypti. The neuron with the smallest amplitude spike responded to the feeding deterrent, quinine, as well as DEET and other insect repellents. Two other ...

  2. Disappearance of Rohon-Beard neurons from the spinal cord of larval Xenopus laevis.

    Science.gov (United States)

    Lamborghini, J E

    1987-10-01

    Rohon-Beard neurons are primary sensory cells located in the spinal cord of embryonic lower vertebrates. The kinetics of their normal, gradual, but complete disappearance in Xenopus tadpoles has been followed. Levels of acid phosphatase activity, a common histochemical correlate of cell death, were assayed and found to increase at the time of onset of disappearance of Rohon-Beard cells. Ultrastructural examination revealed the presence of numerous secondary lysosomes, swelling of endoplasmic reticulum and mitochondria, and a decrease in nuclear density. The disappearance of Rohon-Beard neurons may be attributed to autophagic cell death involving lysosomal acid hydrolases. This process begins only a few days after the maturation of voltage- and neurotransmitter-dependent membrane conductances and the electrical uncoupling of these neurons. The loss of Rohon-Beard neurons in embryos whose development was arrested by crowding was appropriate for the developmental stage of the animals rather than their chronological age.

  3. Reelin signaling in the migration of ventral brain stem and spinal cord neurons

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    Sandra eBlaess

    2016-03-01

    Full Text Available The extracellular matrix protein Reelin is an important orchestrator of neuronal migration during the development of the central nervous system. While its role and mechanism of action have been extensively studied and reviewed in the formation of dorsal laminar brain structures like the cerebral cortex, hippocampus, and cerebellum, its functions during the neuronal migration events that result in the nuclear organization of the ventral central nervous system are less well understood. In an attempt to delineate an underlying pattern of Reelin action in the formation of neuronal cell clusters, this review highlights the role of Reelin signaling in the migration of neuronal populations that originate in the ventral brain stem and the spinal cord.

  4. Gene expression profiling of two distinct neuronal populations in the rodent spinal cord.

    Directory of Open Access Journals (Sweden)

    Jesper Ryge

    Full Text Available BACKGROUND: In the field of neuroscience microarray gene expression profiles on anatomically defined brain structures are being used increasingly to study both normal brain functions as well as pathological states. Fluorescent tracing techniques in brain tissue that identifies distinct neuronal populations can in combination with global gene expression profiling potentially increase the resolution and specificity of such studies to shed new light on neuronal functions at the cellular level. METHODOLOGY/PRINCIPAL FINDINGS: We examine the microarray gene expression profiles of two distinct neuronal populations in the spinal cord of the neonatal rat, the principal motor neurons and specific interneurons involved in motor control. The gene expression profiles of the respective cell populations were obtained from amplified mRNA originating from 50-250 fluorescently identified and laser microdissected cells. In the data analysis we combine a new microarray normalization procedure with a conglomerate measure of significant differential gene expression. Using our methodology we find 32 genes to be more expressed in the interneurons compared to the motor neurons that all except one have not previously been associated with this neuronal population. As a validation of our method we find 17 genes to be more expressed in the motor neurons than in the interneurons and of these only one had not previously been described in this population. CONCLUSIONS/SIGNIFICANCE: We provide an optimized experimental protocol that allows isolation of gene transcripts from fluorescent retrogradely labeled cell populations in fresh tissue, which can be used to generate amplified aRNA for microarray hybridization from as few as 50 laser microdissected cells. Using this optimized experimental protocol in combination with our microarray analysis methodology we find 49 differentially expressed genes between the motor neurons and the interneurons that reflect the functional

  5. Electroacupuncture reduces the evoked responses of the spinal dorsal horn neurons in ankle-sprained rats

    Science.gov (United States)

    Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon

    2011-01-01

    Acupuncture is shown to be effective in producing analgesia in ankle sprain pain in humans and animals. To examine the underlying mechanisms of the acupuncture-induced analgesia, the effects of electroacupuncture (EA) on weight-bearing forces (WBR) of the affected foot and dorsal horn neuron activities were examined in a rat model of ankle sprain. Ankle sprain was induced manually by overextending ligaments of the left ankle in the rat. Dorsal horn neuron responses to ankle movements or compression were recorded from the lumbar spinal cord using an in vivo extracellular single unit recording setup 1 day after ankle sprain. EA was applied to the SI-6 acupoint on the right forelimb (contralateral to the sprained ankle) by trains of electrical pulses (10 Hz, 1-ms pulse width, 2-mA intensity) for 30 min. After EA, WBR of the sprained foot significantly recovered and dorsal horn neuron activities were significantly suppressed in ankle-sprained rats. However, EA produced no effect in normal rats. The inhibitory effect of EA on hyperactivities of dorsal horn neurons of ankle-sprained rats was blocked by the α-adrenoceptor antagonist phentolamine (5 mg/kg ip) but not by the opioid receptor antagonist naltrexone (10 mg/kg ip). These data suggest that EA-induced analgesia in ankle sprain pain is mediated mainly by suppressing dorsal horn neuron activities through α-adrenergic descending inhibitory systems at the spinal level. PMID:21389301

  6. Spinal muscular atrophy: a motor neuron disorder or a multi-organ disease?

    Science.gov (United States)

    Shababi, Monir; Lorson, Christian L; Rudnik-Schöneborn, Sabine S

    2014-01-01

    Spinal muscular atrophy (SMA) is an autosomal recessive disorder that is the leading genetic cause of infantile death. SMA is characterized by loss of motor neurons in the ventral horn of the spinal cord, leading to weakness and muscle atrophy. SMA occurs as a result of homozygous deletion or mutations in Survival Motor Neuron-1 (SMN1). Loss of SMN1 leads to a dramatic reduction in SMN protein, which is essential for motor neuron survival. SMA disease severity ranges from extremely severe to a relatively mild adult onset form of proximal muscle atrophy. Severe SMA patients typically die mostly within months or a few years as a consequence of respiratory insufficiency and bulbar paralysis. SMA is widely known as a motor neuron disease; however, there are numerous clinical reports indicating the involvement of additional peripheral organs contributing to the complete picture of the disease in severe cases. In this review, we have compiled clinical and experimental reports that demonstrate the association between the loss of SMN and peripheral organ deficiency and malfunction. Whether defective peripheral organs are a consequence of neuronal damage/muscle atrophy or a direct result of SMN loss will be discussed. © 2013 Anatomical Society.

  7. [Changes in the neurons of the spinal cord and spinal ganglia in hypokinesia (a neuromorphological and histochemical study)].

    Science.gov (United States)

    Nasyrov, R A; Konovalov, G V

    1982-05-01

    On 62 white male rats at hypokinesia lasting for 7-60 days, motoneurons and neural cells of the lumbar sensitive ganglia have been studied at the level of L2--L4. Certain changes in the spinal ganglia have been neurohistologically revealed beginning from the 30th day of the experiment. In most of the neurons, mainly in large ones, phenomena of central chromatolysis are observed. In one-third of the cells, nuclear hyperchromatosis of various intensity is noted. As the experiment proceeds, the changes acquire a well developed character. In the spinal motoneurons, on the 30th-45th day of the experiment, peripheral chromatolysis, moderate nuclear hyperchromatosis nuclear hypertrophy are detected. Satellite neuroglia is increased according to the "Umklammerying" phenomenon. Cytophotometric investigation of SDG, NAD-D and AF demonstrates certain discoordination in their activity. On the 7th day, SDG and NAD-D activity in the spinal ganglia increases. Beginning from the 30th day, SDG and NAD-D activity in the objects studied decreases, while that of LDG and AF increases. Hypoxia is suggested to be the cause of the disorders observed. A supposition is made that the high AF activity could result in the disturbed activity of the enzymes localizing in mitochondria.

  8. Protective Effects of Two Constituents of Chinese Herbs on Spinal Motor Neurons from Embryonic Rats with Hypoxia Injury

    OpenAIRE

    Chen, Jian-feng; Fan, Jian; Tian, Xiao-wu; Tang, Tian-si

    2011-01-01

    Neuroprotective agents are becoming significant tools in the repair of central nervous system injuries. In this study, we determined whether ginkgolides (Gin, extract of GinkgoBiloba) and Acanthopanax senticosus saponins (ASS, flavonoids extracted from Acanthopanax herbal preparations) have protective effects on rat spinal cords exposed to anoxia and we explored the mechanisms that underlie the protective effects. Spinal motor neurons (SMNs) from rat spinal cords were obtained and divided int...

  9. Neuronal networks and nociceptive processing in the dorsal horn of the spinal cord.

    Science.gov (United States)

    Cordero-Erausquin, Matilde; Inquimbert, Perrine; Schlichter, Rémy; Hugel, Sylvain

    2016-12-03

    The dorsal horn (DH) of the spinal cord receives a variety of sensory information arising from the inner and outer environment, as well as modulatory inputs from supraspinal centers. This information is integrated by the DH before being forwarded to brain areas where it may lead to pain perception. Spinal integration of this information relies on the interplay between different DH neurons forming complex and plastic neuronal networks. Elements of these networks are therefore potential targets for new analgesics and pain-relieving strategies. The present review aims at providing an overview of the current knowledge on these networks, with a special emphasis on those involving interlaminar communication in both physiological and pathological conditions. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  10. Abundance of gap junctions at glutamatergic mixed synapses in adult Mosquitofish spinal cord neurons

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    Jose L Serrano-Velez

    2014-06-01

    Full Text Available Dye-coupling, whole-mount immunohistochemistry for gap junction channel protein connexin 35 (Cx35, and freeze-fracture replica immunogold labeling (FRIL reveal an abundance of electrical synapses/gap junctions at glutamatergic mixed synapses in the 14th spinal segment that innervates the adult male gonopodium of Western Mosquitofish, Gambusia affinis (Mosquitofish.To study gap junctions’ role in fast motor behavior, we used a minimally-invasive neural-tract-tracing technique to introduce gap junction-permeant or -impermeant dyes into deep muscles controlling the gonopodium of the adult male Mosquitofish, a teleost fish that rapidly transfers (complete in 50 of the 62 gap junctions at mixed synapses are in the 14th spinal segment.Our results support and extend studies showing gap junctions at mixed synapses in spinal cord segments involved in control of genital reflexes in rodents, and they suggest a link between mixed synapses and fast motor behavior. The findings provide a basis for studies of specific roles of spinal neurons in the generation/regulation of sex-specific behavior and for studies of gap junctions’ role in regulating fast motor behavior. Finally, the CoPA IN provides a novel candidate neuron for future studies of gap junctions and neural control of fast motor behaviors.

  11. Bioenergetic status modulates motor neuron vulnerability and pathogenesis in a zebrafish model of spinal muscular atrophy.

    Science.gov (United States)

    Boyd, Penelope J; Tu, Wen-Yo; Shorrock, Hannah K; Groen, Ewout J N; Carter, Roderick N; Powis, Rachael A; Thomson, Sophie R; Thomson, Derek; Graham, Laura C; Motyl, Anna A L; Wishart, Thomas M; Highley, J Robin; Morton, Nicholas M; Becker, Thomas; Becker, Catherina G; Heath, Paul R; Gillingwater, Thomas H

    2017-04-01

    Degeneration and loss of lower motor neurons is the major pathological hallmark of spinal muscular atrophy (SMA), resulting from low levels of ubiquitously-expressed survival motor neuron (SMN) protein. One remarkable, yet unresolved, feature of SMA is that not all motor neurons are equally affected, with some populations displaying a robust resistance to the disease. Here, we demonstrate that selective vulnerability of distinct motor neuron pools arises from fundamental modifications to their basal molecular profiles. Comparative gene expression profiling of motor neurons innervating the extensor digitorum longus (disease-resistant), gastrocnemius (intermediate vulnerability), and tibialis anterior (vulnerable) muscles in mice revealed that disease susceptibility correlates strongly with a modified bioenergetic profile. Targeting of identified bioenergetic pathways by enhancing mitochondrial biogenesis rescued motor axon defects in SMA zebrafish. Moreover, targeting of a single bioenergetic protein, phosphoglycerate kinase 1 (Pgk1), was found to modulate motor neuron vulnerability in vivo. Knockdown of pgk1 alone was sufficient to partially mimic the SMA phenotype in wild-type zebrafish. Conversely, Pgk1 overexpression, or treatment with terazosin (an FDA-approved small molecule that binds and activates Pgk1), rescued motor axon phenotypes in SMA zebrafish. We conclude that global bioenergetics pathways can be therapeutically manipulated to ameliorate SMA motor neuron phenotypes in vivo.

  12. Bioenergetic status modulates motor neuron vulnerability and pathogenesis in a zebrafish model of spinal muscular atrophy.

    Directory of Open Access Journals (Sweden)

    Penelope J Boyd

    2017-04-01

    Full Text Available Degeneration and loss of lower motor neurons is the major pathological hallmark of spinal muscular atrophy (SMA, resulting from low levels of ubiquitously-expressed survival motor neuron (SMN protein. One remarkable, yet unresolved, feature of SMA is that not all motor neurons are equally affected, with some populations displaying a robust resistance to the disease. Here, we demonstrate that selective vulnerability of distinct motor neuron pools arises from fundamental modifications to their basal molecular profiles. Comparative gene expression profiling of motor neurons innervating the extensor digitorum longus (disease-resistant, gastrocnemius (intermediate vulnerability, and tibialis anterior (vulnerable muscles in mice revealed that disease susceptibility correlates strongly with a modified bioenergetic profile. Targeting of identified bioenergetic pathways by enhancing mitochondrial biogenesis rescued motor axon defects in SMA zebrafish. Moreover, targeting of a single bioenergetic protein, phosphoglycerate kinase 1 (Pgk1, was found to modulate motor neuron vulnerability in vivo. Knockdown of pgk1 alone was sufficient to partially mimic the SMA phenotype in wild-type zebrafish. Conversely, Pgk1 overexpression, or treatment with terazosin (an FDA-approved small molecule that binds and activates Pgk1, rescued motor axon phenotypes in SMA zebrafish. We conclude that global bioenergetics pathways can be therapeutically manipulated to ameliorate SMA motor neuron phenotypes in vivo.

  13. Sensitization of spinal cord nociceptive neurons with a conjugate of substance P and cholera toxin.

    Science.gov (United States)

    Caudle, Robert M; Mannes, Andrew J; Keller, Jason; Perez, Federico M; Suckow, Shelby K; Neubert, John K

    2007-05-10

    Several investigators have coupled toxins to neuropeptides for the purpose of lesioning specific neurons in the central nervous system. By producing deficits in function these toxin conjugates have yielded valuable information about the role of these cells. In an effort to specifically stimulate cells rather than kill them we have conjugated the neuropeptide substance P to the catalytic subunit of cholera toxin (SP-CTA). This conjugate should be taken up selectively by neurokinin receptor expressing neurons resulting in enhanced adenylate cyclase activity and neuronal firing. The conjugate SP-CTA stimulates adenylate cyclase in cultured cells that are transfected with either the NK1 or NK2 receptor, but not the NK3 receptor. We further demonstrate that intrathecal injection of SP-CTA in rats induces the phosphorylation of the transcription factor cyclic AMP response element binding protein (CREB) and also enhances the expression of the immediate early gene c-Fos. Behaviorally, low doses of SP-CTA (1 microg) injected intrathecally produce thermal hyperalgesia. At higher doses (10 microg) peripheral sensitivity is suppressed suggesting that descending inhibitory pathways may be activated by the SP-CTA induced sensitization of spinal cord neurons. The finding that stimulation of adenylate cyclase in neurokinin receptor expressing neurons in the spinal cord produces thermal hyperalgesia is consistent with the known actions of these neurons. These data demonstrate that cholera toxin can be targeted to specific cell types by coupling the catalytic subunit to a peptide agonist for a g-protein coupled receptor. Furthermore, these results demonstrate that SP-CTA can be used as a tool to study sensitization of central neurons in vivo in the absence of an injury.

  14. Sensitization of spinal cord nociceptive neurons with a conjugate of substance P and cholera toxin

    Directory of Open Access Journals (Sweden)

    Perez Federico M

    2007-05-01

    Full Text Available Abstract Background Several investigators have coupled toxins to neuropeptides for the purpose of lesioning specific neurons in the central nervous system. By producing deficits in function these toxin conjugates have yielded valuable information about the role of these cells. In an effort to specifically stimulate cells rather than kill them we have conjugated the neuropeptide substance P to the catalytic subunit of cholera toxin (SP-CTA. This conjugate should be taken up selectively by neurokinin receptor expressing neurons resulting in enhanced adenylate cyclase activity and neuronal firing. Results The conjugate SP-CTA stimulates adenylate cyclase in cultured cells that are transfected with either the NK1 or NK2 receptor, but not the NK3 receptor. We further demonstrate that intrathecal injection of SP-CTA in rats induces the phosphorylation of the transcription factor cyclic AMP response element binding protein (CREB and also enhances the expression of the immediate early gene c-Fos. Behaviorally, low doses of SP-CTA (1 μg injected intrathecally produce thermal hyperalgesia. At higher doses (10 μg peripheral sensitivity is suppressed suggesting that descending inhibitory pathways may be activated by the SP-CTA induced sensitization of spinal cord neurons. Conclusion The finding that stimulation of adenylate cyclase in neurokinin receptor expressing neurons in the spinal cord produces thermal hyperalgesia is consistent with the known actions of these neurons. These data demonstrate that cholera toxin can be targeted to specific cell types by coupling the catalytic subunit to a peptide agonist for a g-protein coupled receptor. Furthermore, these results demonstrate that SP-CTA can be used as a tool to study sensitization of central neurons in vivo in the absence of an injury.

  15. Leukotriene enhances NMDA-induced inward currents in dorsal horn neurons of the rat spinal cord after peripheral nerve injury.

    Science.gov (United States)

    Kiyoyuki, Yasukuni; Taniguchi, Wataru; Okubo, Masamichi; Yamanaka, Hiroki; Kobayashi, Kimiko; Nishio, Naoko; Nakatsuka, Terumasa; Noguchi, Koichi

    2015-09-09

    LTB4 is classified as a leukotriene (LT), a group of lipid mediators that are derived from arachidonic acid. It is recognized that leukotrienes are involved in the pathogenesis of many diseases, including peripheral inflammatory pain. However, little is known about the effects of leukotrienes on the spinal dorsal horn during neuropathic pain. Previously, we reported that there was increased expression of 5-lipoxygenase (5-LO) at spinal microglia, and the leukotriene B4 receptor 1 (BLT1), a high affinity receptor of LTB4, in spinal neurons in spared nerve injury (SNI) model rats. In the present study, we examined the effects of LTB4 on spinal dorsal horn neurons in both naïve and SNI model rats using patch-clamp methods. Bath application of LTB4 did not change AMPA receptor-mediated spontaneous excitatory postsynaptic currents (sEPSCs) or membrane potentials. However, we found that LTB4 enhanced the amplitude of NMDA receptor-mediated sEPSCs and significantly increased exogenous NMDA-induced inward currents in SNI model rats. This increase of inward currents could be inhibited by a selective LTB4 antagonist, U75302, as well as a GDP-β-S, a G-protein inhibitor. These results indicate that both increased LTB4 from spinal microglia or increased BLT1 in spinal neurons after peripheral nerve injury can enhance the activity of NMDA receptors through intracellular G-proteins in spinal dorsal horn neurons. Our findings showed that LTB4, which may originate from microglia, can activate BLT1 receptors which are expressed on the membrane of spinal dorsal horn neurons during neuropathic pain. This glia-neuron interaction induces the enhancement of NMDA currents through intracellular G-proteins. The enhancement of NMDA receptor sensitivity of dorsal horn neurons may lead to central sensitization, leading to mechanical pain hypersensitivity.

  16. Interferon-gamma potentiates NMDA receptor signaling in spinal dorsal horn neurons via microglia-neuron interaction.

    Science.gov (United States)

    Sonekatsu, Mayumi; Taniguchi, Wataru; Yamanaka, Manabu; Nishio, Naoko; Tsutsui, Shunji; Yamada, Hiroshi; Yoshida, Munehito; Nakatsuka, Terumasa

    2016-01-01

    Glia-neuron interactions play an important role in the development of neuropathic pain. Expression of the pro-inflammatory cytokne →cytokine Interferon-gamma (IFNγ) is upregulated in the dorsal horn after peripheral nerve injury, and intrathecal IFNγ administration induces mechanical allodynia in rats. A growing body of evidence suggests that IFNγ might be involved in the mechanisms of neuropathic pain, but its effects on the spinal dorsal horn are unclear. We performed blind whole-cell patch-clamp recording to investigate the effect of IFNγ on postsynaptic glutamate-induced currents in the substantia gelatinosa neurons of spinal cord slices from adult male rats. IFNγ perfusion significantly enhanced the amplitude of NMDA-induced inward currents in substantia gelatinosa neurons, but did not affect AMPA-induced currents. The facilitation of NMDA-induced current by IFNγ was inhibited by bath application of an IFNγ receptor-selective antagonist. Adding the Janus activated kinase inhibitor tofacitinib to the pipette solution did not affect the IFNγ-induced facilitation of NMDA-induced currents. However, the facilitatory effect of IFNγ on NMDA-induced currents was inhibited by perfusion of the microglial inhibitor minocycline. These results suggest that IFNγ binds the microglial IFNγ receptor and enhances NMDA receptor activity in substantia gelatinosa neurons. Next, to identify the effector of signal transmission from microglia to dorsal horn neurons, we added an inhibitor of G proteins, GDP-β-S, to the pipette solution. In a GDP-β-S-containing pipette solution, IFNγ-induced potentiation of the NMDA current was significantly suppressed after 30 min. In addition, IFNγ-induced potentiation of NMDA currents was blocked by application of a selective antagonist of CCR2, and its ligand CCL2 increased NMDA-induced currents. Our findings suggest that IFNγ enhance the amplitude of NMDA-induced inward currents in substantia gelatinosa neurons via microglial

  17. Interferon-gamma potentiates NMDA receptor signaling in spinal dorsal horn neurons via microglia–neuron interaction

    Science.gov (United States)

    Sonekatsu, Mayumi; Yamanaka, Manabu; Nishio, Naoko; Tsutsui, Shunji; Yamada, Hiroshi; Yoshida, Munehito; Nakatsuka, Terumasa

    2016-01-01

    Background Glia–neuron interactions play an important role in the development of neuropathic pain. Expression of the pro-inflammatory cytokne →cytokine Interferon-gamma (IFNγ) is upregulated in the dorsal horn after peripheral nerve injury, and intrathecal IFNγ administration induces mechanical allodynia in rats. A growing body of evidence suggests that IFNγ might be involved in the mechanisms of neuropathic pain, but its effects on the spinal dorsal horn are unclear. We performed blind whole-cell patch-clamp recording to investigate the effect of IFNγ on postsynaptic glutamate-induced currents in the substantia gelatinosa neurons of spinal cord slices from adult male rats. Results IFNγ perfusion significantly enhanced the amplitude of NMDA-induced inward currents in substantia gelatinosa neurons, but did not affect AMPA-induced currents. The facilitation of NMDA-induced current by IFNγ was inhibited by bath application of an IFNγ receptor-selective antagonist. Adding the Janus activated kinase inhibitor tofacitinib to the pipette solution did not affect the IFNγ-induced facilitation of NMDA-induced currents. However, the facilitatory effect of IFNγ on NMDA-induced currents was inhibited by perfusion of the microglial inhibitor minocycline. These results suggest that IFNγ binds the microglial IFNγ receptor and enhances NMDA receptor activity in substantia gelatinosa neurons. Next, to identify the effector of signal transmission from microglia to dorsal horn neurons, we added an inhibitor of G proteins, GDP-β-S, to the pipette solution. In a GDP-β-S–containing pipette solution, IFNγ-induced potentiation of the NMDA current was significantly suppressed after 30 min. In addition, IFNγ-induced potentiation of NMDA currents was blocked by application of a selective antagonist of CCR2, and its ligand CCL2 increased NMDA-induced currents. Conclusion Our findings suggest that IFNγ enhance the amplitude of NMDA-induced inward currents in substantia

  18. Burst-generating neurones in the dorsal horn in an in vitro preparation of the turtle spinal cord

    DEFF Research Database (Denmark)

    Russo, R E; Hounsgaard, J

    1996-01-01

    1. In transverse slices of the spinal cord of the turtle, intracellular recordings were used to characterize and analyse the responses to injected current and activation of primary afferents in dorsal horn neurones. 2. A subpopulation of neurones, with cell bodies located centrally in the dorsal...

  19. Plateau-generating neurones in the dorsal horn in an in vitro preparation of the turtle spinal cord

    DEFF Research Database (Denmark)

    Russo, R E; Hounsgaard, J

    1996-01-01

    1. In transverse slices of the spinal cord of the turtle, intracellular recordings were used to characterize and analyse the responses to injected current and activation of primary afferents in dorsal horn neurones. 2. A subpopulation of neurones, with cell bodies located laterally in the deep...

  20. Development of a high-affinity GABA uptake system in embryonic amphibian spinal neurons.

    Science.gov (United States)

    Lamborghini, J E; Iles, A

    1985-11-01

    High-affinity uptake systems for amino acid neurotransmitter precursors have been highly correlated with the use of the particular amino acid or its derivative as a transmitter. We have found interneurons in the Xenopus embryo spinal cord which accumulate GABA by a high-affinity uptake system. They originate near the end of gastrulation and their ability to accumulate GABA first appears at the early tail bud stage. By position and appearance they are comparable to some of the embryonic interneurons described by A. Roberts and J. D. W. Clarke (1982, Phil. Trans. R. Soc. London Ser. B 296, 195-212). GABA-accumulating neurons also develop in dissociated cell cultures made from the presumptive spinal cord of neural plate stage Xenopus embryos. GABA accumulation in cultured neurons, as in cells in vivo, occurs via a high-affinity uptake system; GABA-accumulating cells have the same time of origin as the cells in vivo, and the ability to accumulate GABA in the population of cultured neurons appears at a time equivalent to that observed in intact sibling embryos. Thus it seems likely that the population of GABA-accumulating neurons developing in cell culture corresponds to the GABA-accumulating interneurons in vivo. The development of these neurons in dissociated cell cultures permits perturbation experiments that would be difficult to perform in vivo. We have examined the development of high-affinity GABA uptake in conditions that permit no electrical impulse activity in the cultures. The onset and extent of development of GABA accumulation in the neuronal population are normal under these conditions.

  1. Is spinal muscular atrophy a disease of the motor neurons only: pathogenesis and therapeutic implications?

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    Simone, Chiara; Ramirez, Agnese; Bucchia, Monica; Rinchetti, Paola; Rideout, Hardy; Papadimitriou, Dimitra; Re, Diane B; Corti, Stefania

    2016-03-01

    Spinal muscular atrophy (SMA) is a genetic neurological disease that causes infant mortality; no effective therapies are currently available. SMA is due to homozygous mutations and/or deletions in the survival motor neuron 1 gene and subsequent reduction of the SMN protein, leading to the death of motor neurons. However, there is increasing evidence that in addition to motor neurons, other cell types are contributing to SMA pathology. In this review, we will discuss the involvement of non-motor neuronal cells, located both inside and outside the central nervous system, in disease onset and progression. Even if SMN restoration in motor neurons is needed, it has been shown that optimal phenotypic amelioration in animal models of SMA requires a more widespread SMN correction. It has been demonstrated that non-motor neuronal cells are also involved in disease pathogenesis and could have important therapeutic implications. For these reasons it will be crucial to take this evidence into account for the clinical translation of the novel therapeutic approaches.

  2. Embryonic Cell Grafts in a Culture Model of Spinal Cord Lesion: Neuronal Relay Formation is Essential for Functional Regeneration

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    Anne Tscherter

    2016-09-01

    Full Text Available Presently there exists no cure for spinal cord injury. However, transplantation of embryonic tissue into spinal cord lesions resulted in axon outgrowth across the lesion site and some functional recovery, fostering hope for future stem cell therapies. Although in vivo evidence for functional recovery is given, the exact cellular mechanism of the graft support remains elusive: either the grafted cells provide a permissive environment for the host tissue to regenerate itself or the grafts actually integrate functionally into the host neuronal network reconnecting the separated spinal cord circuits. We tested the two hypotheses in an in vitro spinal cord lesion model that is based on propagation of activity between two rat organotypic spinal cord slices in culture. Transplantation of dissociated cells from E14 rat spinal cord or forebrain re-established the relay of activity over the lesion site and, thus, provoked functional regeneration. Combining patch-clamp recordings from transplanted cells with network activity measurements from the host tissue on multi-electrode arrays we here show that neurons differentiate from the grafted cells and integrate into the host circuits. Optogenetic silencing of neurons developed from transplanted embryonic mouse forebrain cells provides clear evidence that they replace the lost neuronal connections to relay and synchronize activity between the separated spinal cord circuits. In contrast, transplantation of neurospheres induced neither the differentiation of mature neurons from the grafts nor an improvement of functional regeneration. Together these findings suggest, that the formation of neuronal relays from grafted embryonic cells is essential to re-connect segregated spinal cord circuits.

  3. Contributions of intrinsic motor neuron properties to the production of rhythmic motor output in the mammalian spinal cord

    DEFF Research Database (Denmark)

    Kiehn, O; Kjaerulff, O; Tresch, M C

    2000-01-01

    showing that the neonatal rat spinal cord can produce a stable motor rhythm in the absence of spike activity in premotor interneuronal networks. These coordinated motor neuron oscillations are dependent on NMDA-evoked pacemaker properties, which are synchronized across gap junctions. We discuss...... the functional relevance for such coordinated oscillations in immature and mature spinal motor systems.......Motor neurons are endowed with intrinsic and conditional membrane properties that may shape the final motor output. In the first half of this paper we present data on the contribution of I(h), a hyperpolarization-activated inward cation current, to phase-transition in motor neurons during rhythmic...

  4. TOXOPLASMOSIS: MORPHOLOGICAL AND MORPHOMETRIC EVALUATION OF SPINAL CORD NEURONS FROM NONSYMPTOMATIC SEROPOSITIVE DOGS

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    Alessandra Cristina Francischini de Carvalho

    2015-04-01

    Full Text Available The aim of this work was to analyze the neuron morphology and morphometry of cervical, thoracic and lumbar areas of nonsymptomatic seropositive dogs’ spinal cord for toxoplasmosis. Twenty indefinite-breed adult dogs were used; ten dogs were healthy, with negative serology for toxoplasmosis, and were used as the control group (group 1, and ten dogs were nonsymptomatic but seropositive for toxoplasmosis (group 2. After the microtomy, with interval of 100 micrometers (µm, the histological 5-µm-thick cuts were dyed by hematoxylin-eosin and Masson's trichrome techniques. The glass slides were analyzed under light microscope to examine the neuron morphology. The parameters considered for the morphometric analysis were area, perimeter, maximum diameter, minimum diameter and shape factor of cytoplasm and nucleus of neuron. The results were statistically analyzed by Student’s t test at 5% probability level. The morphological characteristics between the two groups were similar and according to literature. The morphometric results showed that there were changes in neurons size and structure, and increase and loss of star shape were noticed in seropositive animals. The results suggest that the neurons of these dogs, yet nonsymptomatic, can have lost their conductor function.

  5. Excitatory inputs to four types of spinocerebellar tract neurons in the cat and the rat thoraco-lumbar spinal cord

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    Shrestha, Sony Shakya; Bannatyne, B Anne; Jankowska, Elzbieta; Hammar, Ingela; Nilsson, Elin; Maxwell, David J

    2012-01-01

    The cerebellum receives information from the hindlimbs through several populations of spinocerebellar tract neurons. Although the role of these neurons has been established in electrophysiological experiments, the relative contribution of afferent fibres and central neurons to their excitatory input has only been estimated approximately so far. Taking advantage of differences in the immunohistochemistry of glutamatergic terminals of peripheral afferents and of central neurons (with vesicular glutamate transporters VGLUT1 or VGLUT2, respectively), we compared sources of excitatory input to four populations of spinocerebellar neurons in the thoraco-lumbar spinal cord: dorsal spinocerebellar tract neurons located in Clarke's column (ccDSCT) and in the dorsal horn (dhDSCT) and ventral spinocerebellar tract (VSCT) neurons including spinal border (SB) neurons. This was done on 22 electrophysiologically identified intracellularly labelled neurons in cats and on 80 neurons labelled by retrograde transport of cholera toxin b subunit injected into the cerebellum of rats. In both species distribution of antibodies against VGLUT1 and VGLUT2 on SB neurons (which have dominating inhibitory input from limb muscles), revealed very few VGLUT1 contacts and remarkably high numbers of VGLUT2 contacts. In VSCT neurons with excitatory afferent input, the number of VGLUT1 contacts was relatively high although VGLUT2 contacts likewise dominated, while the proportions of VGLUT1 and VGLUT2 immunoreactive terminals were the reverse on the two populations of DSCT neurons. These findings provide morphological evidence that SB neurons principally receive excitatory inputs from central neurons and provide the cerebellum with information regarding central neuronal activity. PMID:22371473

  6. Methylglyoxal Requires AC1 and TRPA1 to Produce Pain and Spinal Neuron Activation

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    Ryan B. Griggs

    2017-12-01

    Full Text Available Methylglyoxal (MG is a metabolite of glucose that may contribute to peripheral neuropathy and pain in diabetic patients. MG increases intracellular calcium in sensory neurons and produces behavioral nociception via the cation channel transient receptor potential ankyrin 1 (TRPA1. However, rigorous characterization of an animal model of methylglyoxal-evoked pain is needed, including testing whether methylglyoxal promotes negative pain affect. Furthermore, it remains unknown whether methylglyoxal is sufficient to activate neurons in the spinal cord dorsal horn, whether this requires TRPA1, and if the calcium-sensitive adenylyl cyclase 1 isoform (AC1 contributes to MG-evoked pain. We administered intraplantar methylglyoxal and then evaluated immunohistochemical phosphorylation of extracellular signal-regulated kinase (p-ERK and multiple pain-like behaviors in wild-type rats and mice and after disruption of either TRPA1 or AC1. Methylglyoxal produced conditioned place avoidance (CPA (a measure of affective pain, dose-dependent licking and lifting nociceptive behaviors, hyperalgesia to heat and mechanical stimulation, and p-ERK in the spinal cord dorsal horn. TRPA1 knockout or intrathecal administration of a TRPA1 antagonist (HC030031 attenuated methylglyoxal-evoked p-ERK, nociception, and hyperalgesia. AC1 knockout abolished hyperalgesia but not nociceptive behaviors. These results indicate that intraplantar administration of methylglyoxal recapitulates multiple signs of painful diabetic neuropathy found in animal models of or patients with diabetes, including the activation of spinal nociresponsive neurons and the potential involvement of a TRPA1-AC1 sensitization mechanism. We conclude that administration of MG is a valuable model for investigating both peripheral and central components of a MG-TRPA1-AC1 pathway that contribute to painful diabetic neuropathy.

  7. Confocal imaging of autonomic preganglionic neurons in the spinal cord of the caecilian Typhlonectes natans (Amphibia: Gymnophiona).

    Science.gov (United States)

    Zaccone, Daniele; Lauriano, Eugenia Rita; Capillo, Gioele; Zuwała, Krystyna; Budzik, Karolina Agata; Kuciel, Michał; Zaccone, Giacomo

    2014-10-01

    Little is known about the spinal sympathetic organization in the caecilian amphibians. We examined for the first time the location of sympathetic preganglionic neurons (SPNs) in the spinal cord using a panel of specific markers expressed in SPNs. The SPNs of anuran amphibians form two cell columns segregated mainly in the lateral and medial marginal areas of the central gray matter. In the caecilian Typhlonectes natans immunoreactivity for galanin and ChAT is found in most laterally arranged neurons lying in spinal segments 2-7. They are encircled by TH- and nNOS-immunoreactive nerve fibers. These neurons might project specifically to a population of adrenergic sympathetic postganglionic neurons in paravertebral ganglia and/or non-adrenergic sympathetic postganglionic neurons in the celiac ganglia. However the segmental restriction and target specificity of the neurons of the species studied are not known. As mucous and granular glands in the dermis may represent one of the peripheral targets of the adrenergic ganglion cells and reflect the prominent preganglionic cell columns, an immunohistochemical study was done also on these glands. Retrograde-tracing studies are, however, needed to study the segmental localization of the preganglionic neurons and their projections to the postganglionic neurons in sympathetic ganglia. Copyright © 2014 Elsevier GmbH. All rights reserved.

  8. PC1, a non-peptide PKR1-preferring antagonist, reduces pain behavior and spinal neuronal sensitization in neuropathic mice.

    Science.gov (United States)

    Guida, F; Lattanzi, R; Boccella, S; Maftei, D; Romano, R; Marconi, V; Balboni, G; Salvadori, S; Scafuro, M A; de Novellis, V; Negri, L; Maione, S; Luongo, L

    2015-01-01

    Peripheral neuropathy is characterized by abnormal pain responses triggered by the release of several mediators and neuronal hyperexcitability at the spinal cord level. Emerging evidence indicates that the enhanced activity of dorsal horn neurons requires communication with glia and microglia, cells that are physiologically involved in neuronal wellbeing. Prokineticins (PKs), which include PK1 and PK2, represent a novel family of chemokines characterized by a unique structural motif comprising five disulfide bonds. They are expressed in the peripheral and central nervous system. PKs bind two G protein coupled receptors, PKR1 and PKR2, and participate in the regulation of several biological processes, including pain sensation. This study aimed to investigate the anti-nociceptive effect of PC1, a non-peptide PKR1-preferring antagonist, in a mouse model of neuropathic pain. To do this, we assessed the activity of spinal cord nociceptive neurons as well as astrocyte and microglia phenotypes after repeated administration of PC1 in vivo. PC1 treatment strongly delayed the development of thermal hyperalgesia and tactile and mechanical allodynia. It also reduced spinal microglial and glial activation 8 days post injury in spared nerve injury (SNI) mice. Neuropathic mice showed an increased level of PK2 protein in the spinal cord, mostly in astrocytes. PC1 treatment completely reversed the increased responsiveness to mechanical stimuli, the decreased threshold of neuronal activation, and the increased spontaneous activity that were observed in nociceptive specific (NS) neurons of SNI mice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Minocycline, a microglial inhibitor, blocks spinal CCL2-induced heat hyperalgesia and augmentation of glutamatergic transmission in substantia gelatinosa neurons.

    Science.gov (United States)

    Huang, Chung-Yu; Chen, Ying-Ling; Li, Allen H; Lu, Juu-Chin; Wang, Hung-Li

    2014-01-10

    Several lines of evidence suggest that CCL2 could initiate the hyperalgesia of neuropathic pain by causing central sensitization of spinal dorsal horn neurons and facilitating nociceptive transmission in the spinal dorsal horn. The cellular and molecular mechanisms by which CCL2 enhances spinal pain transmission and causes hyperalgesia remain unknown. The substantia gelatinosa (lamina II) of the spinal dorsal horn plays a critical role in nociceptive transmission. An activated spinal microglia, which is believed to release pro-inflammatory cytokines including TNF-α, plays an important role in the development of neuropathic pain, and CCL2 is a key mediator for spinal microglia activation. In the present study, we tested the hypothesis that spinal CCL2 causes the central sensitization of substantia gelatinosa neurons and enhances spinal nociceptive transmission by activating the spinal microglia and augmenting glutamatergic transmission in lamina II neurons. CCL2 was intrathecally administered to 2-month-old male rats. An intrathecal injection of CCL2 induced heat hyperalgesia, which was assessed using the hot plate test. Whole-cell voltage-clamp recordings substantia gelatinosa neurons in spinal cord slices were performed to record glutamatergic excitatory postsynaptic currents (EPSCs) and GABAergic inhibitory postsynaptic currents (IPSCs). The hot plate test showed that 1 day after the intrathecal injection of CCL2 (1 μg), the latency of hind-paw withdrawal caused by a heat stimulus was significantly reduced in rats. One day after the intrathecal administration of CCL2, the amplitude of the evoked glutamatergic EPSCs and the frequency of spontaneous glutamatergic miniature EPSCs (mEPSCs) were significantly increased in outer lamina II neurons. Intrathecal co-injection of minocycline, a specific inhibitor of microglial activation, and CCL2 blocked the CCL2-induced reduction in the latency of hind-paw withdrawal and thermal hyperalgesia. Following intrathecal co

  10. Regulation of autophagy by AMP-activated protein kinase/sirtuin 1 pathway reduces spinal cord neurons damage.

    Science.gov (United States)

    Yan, Peng; Bai, Liangjie; Lu, Wei; Gao, Yuzhong; Bi, Yunlong; Lv, Gang

    2017-09-01

    AMP-activated protein kinase/sirtuin 1 (AMPK/SIRT1) signaling pathway has been proved to be involved in the regulation of autophagy in various models. The aim of this study was to evaluate the effect of AMPK/SIRT1 pathway on autophagy after spinal cord injury (SCI). The SCI model was established in rats in vivo and the primary spinal cord neurons were subjected to mechanical injury (MI) in vitro . The apoptosis in spinal cord tissue and neurons was assessed by TUNEL staining and Hoechst 33342 staining, respectively. The autophagy-related proteins levels were detected by Western blot. The activation of AMPK/SIRT1 pathway was determined by Western blot and immunohistochemical staining. We found that the apoptosis of spinal cord tissue and cell damage of spinal cord neurons was obvious after the trauma. The ratio of LC3II/LC3I and level of p62 were first increased significantly and then decreased after the trauma in vivo and in vitro , indicating the defect in autophagy. The levels of p-AMPK and SIRT1 were increased obviously after the trauma in vivo and in vitro . Further activation of the AMPK/SIRT1 pathway by pretreatment with resveratrol, a confirmed activator of the AMPK/SIRT1 pathway, alleviated the cell damage and promoted the autophagy flux via downregulation of p62 in spinal cord neurons at 24 hr after MI. Our results demonstrate that regulation of autophagy by AMPK/SIRT1 pathway can restrain spinal cord neurons damage, which may be a potential intervention of SCI.

  11. Regulation of autophagy by AMP-activated protein kinase/ sirtuin 1 pathway reduces spinal cord neurons damage

    Directory of Open Access Journals (Sweden)

    Peng Yan

    2017-09-01

    Full Text Available Objective(s: AMP-activated protein kinase/sirtuin 1 (AMPK/SIRT1 signaling pathway has been proved to be involved in the regulation of autophagy in various models. The aim of this study was to evaluate the effect of AMPK/SIRT1 pathway on autophagy after spinal cord injury (SCI. Materials and Methods:The SCI model was established in rats in vivo and the primary spinal cord neurons were subjected to mechanical injury (MI in vitro. The apoptosis in spinal cord tissue and neurons was assessed by TUNEL staining and Hoechst 33342 staining, respectively. The autophagy-related proteins levels were detected by Western blot. The activation of AMPK/SIRT1 pathway was determined by Western blot and immunohistochemical staining. Results: We found that the apoptosis of spinal cord tissue and cell damage of spinal cord neurons was obvious after the trauma. The ratio of LC3II/LC3I and level of p62 were first increased significantly and then decreased after the trauma in vivo and in vitro, indicating the defect in autophagy. The levels of p-AMPK and SIRT1 were increased obviously after the trauma in vivo and in vitro. Further activation of the AMPK/SIRT1 pathway by pretreatment with resveratrol, a confirmed activator of the AMPK/SIRT1 pathway, alleviated the cell damage and promoted the autophagy flux via downregulation of p62 in spinal cord neurons at 24 hr after MI. Conclusion: Our results demonstrate that regulation of autophagy by AMPK/SIRT1 pathway can restrain spinal cord neurons damage, which may be a potential intervention of SCI.

  12. In vivo tracking of neuronal-like cells by magnetic resonance in rabbit models of spinal cord injury

    Science.gov (United States)

    Zhang, Ruiping; Zhang, Kun; Li, Jianding; Liu, Qiang; Xie, Jun

    2013-01-01

    In vitro experiments have demonstrated that neuronal-like cells derived from bone marrow mesenchymal stem cells can survive, migrate, integrate and help to restore the function and behaviors of spinal cord injury models, and that they may serve as a suitable approach to treating spinal cord injury. However, it is very difficult to track transplanted cells in vivo. In this study, we injected superparamagnetic iron oxide-labeled neuronal-like cells into the subarachnoid space in a rabbit model of spinal cord injury. At 7 days after cell transplantation, a small number of dot-shaped low signal intensity shadows were observed in the spinal cord injury region, and at 14 days, the number of these shadows increased on T2-weighted imaging. Perl's Prussian blue staining detected dot-shaped low signal intensity shadows in the spinal cord injury region, indicative of superparamagnetic iron oxide nanoparticle-labeled cells. These findings suggest that transplanted neuronal-like cells derived from bone marrow mesenchymal stem cells can migrate to the spinal cord injury region and can be tracked by magnetic resonance in vivo. Magnetic resonance imaging represents an efficient noninvasive technique for visually tracking transplanted cells in vivo. PMID:25206659

  13. Nav 1.8-null mice show stimulus-dependent deficits in spinal neuronal activity

    Directory of Open Access Journals (Sweden)

    Wood John N

    2006-02-01

    Full Text Available Abstract Background The voltage gated sodium channel Nav 1.8 has a highly restricted expression pattern to predominantly nociceptive peripheral sensory neurones. Behaviourally Nav 1.8-null mice show an increased acute pain threshold to noxious mechanical pressure and also deficits in inflammatory and visceral, but not neuropathic pain. Here we have made in vivo electrophysiology recordings of dorsal horn neurones in intact anaesthetised Nav 1.8-null mice, in response to a wide range of stimuli to further the understanding of the functional roles of Nav 1.8 in pain transmission from the periphery to the spinal cord. Results Nav 1.8-null mice showed marked deficits in the coding by dorsal horn neurones to mechanical, but not thermal, -evoked responses over the non-noxious and noxious range compared to littermate controls. Additionally, responses evoked to other stimulus modalities were also significantly reduced in Nav 1.8-null mice where the reduction observed to pinch > brush. The occurrence of ongoing spontaneous neuronal activity was significantly less in mice lacking Nav 1.8 compared to control. No difference was observed between groups in the evoked activity to electrical activity of the peripheral receptive field. Conclusion This study demonstrates that deletion of the sodium channel Nav 1.8 results in stimulus-dependent deficits in the dorsal horn neuronal coding to mechanical, but not thermal stimuli applied to the neuronal peripheral receptive field. This implies that Nav 1.8 is either responsible for, or associated with proteins involved in mechanosensation.

  14. Neuron-oligodendrocyte myelination co-culture derived from embryonic rat spinal cord and cerebral cortex.

    Science.gov (United States)

    Pang, Yi; Zheng, Baoying; Kimberly, Simpson L; Cai, Zhengwei; Rhodes, Philip G; Lin, Rick C S

    2012-01-01

    An in vitro myelination model derived from rat central nervous system (CNS) remains to be established. Here, we describe a simple and reproducible myelination culture method using dissociated neuron-oligodendrocyte (OL) co-cultures from either the embryonic day 16 (E16) rat spinal cord or cerebral cortex. The dissociated cells are plated directly on poly-L-lysine-coated cover slips and maintained in a modified myelination medium that supports both OL and neuron differentiation. The spinal cord derived OL progenitor cells develop quickly into myelin basic protein (MBP)+ mature OLs and start to myelinate axons around 17 days in vitro (DIV17). Myelination reaches its peak around six weeks (DIV40) and the typical nodes of Ranvier are revealed by paranodal proteins Caspr and juxaparanodal protein Kv1.2 immunoreactivity. Electron microscopy (EM) shows typical myelination cytoarchitecture and synaptic organization. In contrast, the cortical-derived co-culture requires triiodothyronine (T3) in the culture medium for myelination. Finally, either hypomyelination and/or demyelination can be induced by exposing proinflammatory cytokines or demyelinating agents to the co-culture, suggesting the feasibility of this modified in vitro myelination model for myelin-deficit investigation.

  15. A Role for SMN Exon 7 Splicing in the Selective Vulnerability of Motor Neurons in Spinal Muscular Atrophy

    Science.gov (United States)

    Ruggiu, Matteo; McGovern, Vicki L.; Lotti, Francesco; Saieva, Luciano; Li, Darrick K.; Kariya, Shingo; Monani, Umrao R.; Burghes, Arthur H. M.

    2012-01-01

    Spinal muscular atrophy (SMA) is an inherited motor neuron disease caused by homozygous loss of the Survival Motor Neuron 1 (SMN1) gene. In the absence of SMN1, inefficient inclusion of exon 7 in transcripts from the nearly identical SMN2 gene results in ubiquitous SMN decrease but selective motor neuron degeneration. Here we investigated whether cell type-specific differences in the efficiency of exon 7 splicing contribute to the vulnerability of SMA motor neurons. We show that normal motor neurons express markedly lower levels of full-length SMN mRNA from SMN2 than do other cells in the spinal cord. This is due to inefficient exon 7 splicing that is intrinsic to motor neurons under normal conditions. We also find that SMN depletion in mammalian cells decreases exon 7 inclusion through a negative feedback loop affecting the splicing of its own mRNA. This mechanism is active in vivo and further decreases the efficiency of exon 7 inclusion specifically in motor neurons of severe-SMA mice. Consistent with expression of lower levels of full-length SMN, we find that SMN-dependent downstream molecular defects are exacerbated in SMA motor neurons. These findings suggest a mechanism to explain the selective vulnerability of motor neurons to loss of SMN1. PMID:22037760

  16. κ-Opioid Receptor Inhibition of Calcium Oscillations in Spinal Cord Neurons

    Science.gov (United States)

    Kelamangalath, Lakshmi; Dravid, Shashank M.; George, Joju; Aldrich, Jane V.

    2011-01-01

    Mouse embryonic spinal cord neurons in culture exhibit spontaneous calcium oscillations from day in vitro (DIV) 6 through DIV 10. Such spontaneous activity in developing spinal cord contributes to maturation of synapses and development of pattern-generating circuits. Here we demonstrate that these calcium oscillations are regulated by κ opioid receptors (KORs). The κ opioid agonist dynorphin (Dyn)-A (1–13) suppressed calcium oscillations in a concentration-dependent manner, and both the nonselective opioid antagonist naloxone and the κ-selective blocker norbinaltorphimine eliminated this effect. The KOR-selective agonist (+)-(5α,7α,8β)-N-methyl-N-[7-(1-pyrrolidinyl)-1-oxaspiro[4.5]dec-8-yl]-benzeneacetamide (U69593) mimicked the effect of Dyn-A (1–13) on calcium oscillations. A κ-specific peptide antagonist, zyklophin, was also able to prevent the suppression of calcium oscillations caused by Dyn-A (1–13). These spontaneous calcium oscillations were blocked by 1 μM tetrodotoxin, indicating that they are action potential-dependent. Although the L-type voltage-gated calcium channel blocker nifedipine did not suppress calcium oscillations, the N-type calcium channel blocker ω-conotoxin inhibited this spontaneous response. Blockers of ionotropic glutamate receptors, 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(f)quinoxaline and dizocilpine maleate (MK-801), also suppressed calcium oscillations, revealing a dependence on glutamate-mediated signaling. Finally, we have demonstrated expression of KORs in glutamatergic spinal neurons and localization in a presynaptic compartment, consistent with previous reports of KOR-mediated inhibition of glutamate release. The KOR-mediated inhibition of spontaneous calcium oscillations may therefore be a consequence of presynaptic inhibition of glutamate release. PMID:21422300

  17. In vivo NMDA receptor activation accelerates motor unit maturation, protects spinal motor neurons, and enhances SMN2 gene expression in severe spinal muscular atrophy mice.

    Science.gov (United States)

    Biondi, Olivier; Branchu, Julien; Sanchez, Gabriel; Lancelin, Camille; Deforges, Séverine; Lopes, Philippe; Pariset, Claude; Lécolle, Sylvie; Côté, Jocelyn; Chanoine, Christophe; Charbonnier, Frédéric

    2010-08-25

    Spinal muscular atrophy (SMA), a lethal neurodegenerative disease that occurs in childhood, is caused by the misexpression of the survival of motor neuron (SMN) protein in motor neurons. It is still unclear whether activating motor units in SMA corrects the delay in the postnatal maturation of the motor unit resulting in an enhanced neuroprotection. In the present work, we demonstrate that an adequate NMDA receptor activation in a type 2 SMA mouse model significantly accelerated motor unit postnatal maturation, counteracted apoptosis in the spinal cord, and induced a marked increase of SMN expression resulting from a modification of SMN2 gene transcription pattern. These beneficial effects were dependent on the level of NMDA receptor activation since a treatment with high doses of NMDA led to an acceleration of the motor unit maturation but favored the apoptotic process and decreased SMN expression. In addition, these results suggest that the NMDA-induced acceleration of motor unit postnatal maturation occurred independently of SMN. The NMDA receptor activating treatment strongly extended the life span in two different mouse models of severe SMA. The analysis of the intracellular signaling cascade that lay downstream the activated NMDA receptor revealed an unexpected reactivation of the CaMKII/AKT/CREB (cAMP response element-binding protein) pathway that induced an enhanced SMN expression. Therefore, pharmacological activation of spinal NMDA receptors could constitute a useful strategy for both increasing SMN expression and limiting motor neuron death in SMA spinal cord.

  18. Motor cortex-periaqueductal gray-spinal cord neuronal circuitry may involve in modulation of nociception: a virally mediated transsynaptic tracing study in spinally transected transgenic mouse model.

    Directory of Open Access Journals (Sweden)

    Da-Wei Ye

    Full Text Available Several studies have shown that motor cortex stimulation provided pain relief by motor cortex plasticity and activating descending inhibitory pain control systems. Recent evidence indicated that the melanocortin-4 receptor (MC4R in the periaqueductal gray played an important role in neuropathic pain. This study was designed to assess whether MC4R signaling existed in motor cortex-periaqueductal gray-spinal cord neuronal circuitry modulated the activity of sympathetic pathway by a virally mediated transsynaptic tracing study. Pseudorabies virus (PRV-614 was injected into the left gastrocnemius muscle in adult male MC4R-green fluorescent protein (GFP transgenic mice (n = 15. After a survival time of 4-6 days, the mice (n = 5 were randomly assigned to humanely sacrifice, and spinal cords and brains were removed and sectioned, and processed for PRV-614 visualization. Neurons involved in the efferent control of the left gastrocnemius muscle were identified following visualization of PRV-614 retrograde tracing. The neurochemical phenotype of MC4R-GFP-positive neurons was identified using fluorescence immunocytochemical labeling. PRV-614/MC4R-GFP dual labeled neurons were detected in spinal IML, periaqueductal gray and motor cortex. Our findings support the hypothesis that MC4R signaling in motor cortex-periaqueductal gray-spinal cord neural pathway may participate in the modulation of the melanocortin-sympathetic signaling and contribute to the descending modulation of nociceptive transmission, suggesting that MC4R signaling in motor cortex-periaqueductal gray-spinal cord neural pathway may modulate the activity of sympathetic outflow sensitive to nociceptive signals.

  19. Neonatal bladder inflammation induces long-term visceral pain and altered responses of spinal neurons in adult rats.

    Science.gov (United States)

    Kannampalli, Pradeep; Babygirija, Reji; Zhang, Jiang; Poe, Michael M; Li, Guanguan; Cook, James M; Shaker, Reza; Banerjee, Banani; Sengupta, Jyoti N

    2017-03-27

    Painful events early in life have been shown to increase the incidence of interstitial cystitis/painful bladder syndrome in adulthood. However, the intrinsic mechanism is not well studied. We previously reported that neonatal bladder inflammation causes chronic visceral hypersensitivity along with molecular disruption of spinal GABAergic system in rats. The present study investigates whether these molecular changes affect the integrative function and responses of bladder-sensitive primary afferent and spinal neurons. Neonatal bladder inflammation was induced by intravesicular injection of zymosan during postnatal (P) days 14-16. In adulthood (P60), the viscero-motor response (VMR) to visceral stimuli was significantly inhibited by intrathecal (i.t) HZ166 (GABA Aα-2 agonist) only in neonatally saline-treated, but not in neonatally zymosan-treated rats. HZ166 significantly inhibited the responses of bladder-responsive lumbosacral (LS) spinal neurons to urinary bladder distension (UBD) and slow infusion (SI) in neonatally saline-treated rats. Similar results were also observed in naïve adult rats where HZ166 produced significant inhibition of bladder-responsive spinal neurons. However, HZ166 did not inhibit responses of UBD-responsive spinal neurons from neonatally zymosan-treated rats. The drug did not attenuate the responses of UBD-sensitive pelvic nerve afferent (PNA) fibers to UBD and SI in either group of rats tested. Immunohistochemical studies showed a significantly lower level of GABA Aα-2 receptor expression in the LS spinal cord of neonatally zymosan-treated rats compared to saline-treated rats. These findings indicate that neonatal bladder inflammation leads to functional and molecular alteration of spinal GABA Aα-2 receptor subtypes, which may result in chronic visceral hyperalgesia in adulthood. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Comparative analysis of NADPH-diaphorase positive neurons in the rat, rabbit and pheasant thoracic spinal cord. A histochemical study

    Directory of Open Access Journals (Sweden)

    D Kluchová

    2009-12-01

    Full Text Available The distribution of NADPH-diaphorase (NADPHd activity was investigated and compared in the rat, rabbit and pheasant thoracic spinal cord. The investigation of all spinal cord regions (laminae in three experimental species revealed marked differences in the distribution of NADPH-d activity. Cross sectional analysis of the spinal cord of the rat, rabbit and pheasant confirmed differences in the shape of the gray matter in all examined species. More detailed investigation of Rexed´s laminas showed similar distribution of NADPH-d activity in the spinal cord of the rat and rabbit, which were different when compared with the spinal cord of the pheasant. Ventral horn of the rat and rabbit showed no labelling whereas in pheasant this area possessed a number of scattered, intensively stained neurons. In the location of autonomic preganglionic neurons, differences were found as well. In the rat there was seen a number of densely packed, clearly dark blue coloured neurons. Similarly, these neurons were present in the rabbit spinal cord but they were less numerous. No staining was found in this region of pheasant. Pericentral area (lamina X and intermediate zone (laminaVII revealed the presence of NADPH-d positive neurons in all examined species although they differed in number and shape of their bodies. The dorsal horn showed the presence of NADPH-d staining in all three animals but its distribution was different in medio - lateral direction. It can be suggested that observed differencies in the presence and distribution of NADPH-d activity across the examined species may reflect different fylogenetic development

  1. Electroacupuncture improves microcirculation and neuronal morphology in the spinal cord of a rat model of intervertebral disc extrusion

    Directory of Open Access Journals (Sweden)

    Dai-xun Jiang

    2015-01-01

    Full Text Available Most studies on spinal cord neuronal injury have focused on spinal cord tissue histology and the expression of nerve cell damage and repair-related genes. The importance of the microcirculation is often ignored in spinal cord injury and repair research. Therefore, in this study, we established a rat model of intervertebral disc extrusion by inserting a silica gel pad into the left ventral surface of T 13 . Electroacupuncture was used to stimulate the bilateral Zusanli point (ST36 and Neiting point (ST44 for 14 days. Compared with control animals, blood flow in the first lumbar vertebra (L 1 was noticeably increased in rats given electroacupuncture. Microvessel density in the T 13 segment of the spinal cord was increased significantly as well. The number of normal neurons was higher in the ventral horn of the spinal cord. In addition, vacuolation in the white matter was lessened. No obvious glial cell proliferation was visible. Furthermore, hindlimb motor function was improved significantly. Collectively, our results suggest that electroacupuncture can improve neuronal morphology and microcirculation, and promote the recovery of neurological functions in a rat model of intervertebral disc extrusion.

  2. MicroRNA miR-9 modifies motor neuron columns by a tuning regulation of FoxP1 levels in developing spinal cords

    OpenAIRE

    Otaegi, Gaizka; Pollock, Andrew; Hong, Janet; Sun, Tao

    2011-01-01

    The precise organization of motor neuron subtypes in a columnar pattern in developing spinal cords is controlled by cross-interactions of multiple transcription factors and segmental expressions of Hox genes and their accessory proteins. Accurate expression levels and domains of these regulators are essential for organizing spinal motor neuron columns and axonal projections to target muscles. Here, we show that microRNA miR-9 is transiently expressed in a motor neuron subtype and displays ove...

  3. Microglial Janus kinase/signal transduction and activator of transcription 3 pathway activity directly impacts astrocyte and spinal neuron characteristics

    Czech Academy of Sciences Publication Activity Database

    Molet, J.; Mauborgne, A.; Diallo, Michael; Armand, V.; Geny, D.; Villanueva, L.; Boucher, Y.; Pohl, M.

    2016-01-01

    Roč. 136, č. 1 (2016), s. 133-147 ISSN 0022-3042 R&D Projects: GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : astrocytes * cell plasticity * JAK/STAT3 pathway * microglia conditioned media * spinal cord neurons Subject RIV: FH - Neurology Impact factor: 4.083, year: 2016

  4. Involvement of spinal sensory pathway in ALS and specificity of cord atrophy to lower motor neuron degeneration.

    Science.gov (United States)

    Cohen-Adad, Julien; El Mendili, Mohamed-Mounir; Morizot-Koutlidis, Régine; Lehéricy, Stéphane; Meininger, Vincent; Blancho, Sophie; Rossignol, Serge; Benali, Habib; Pradat, Pierre-François

    2013-01-01

    Our objective was to demonstrate that ALS patients have sensory pathway involvement and that local cord atrophy reflects segmental lower motor neuron involvement. Twenty-nine ALS patients with spinal onset and twenty-one healthy controls were recruited. Diffusion tensor imaging (DTI), magnetization transfer and atrophy index were measured in the spinal cord, complemented with transcranial magnetic stimulations. Metrics were quantified within the lateral corticospinal and the dorsal segments of the cervical cord. Significant differences were detected between patients and controls for DTI and magnetization transfer metrics in the lateral and dorsal segments of the spinal cord. Fractional anisotropy correlated with ALSFRS-R (p = 0.04) and motor threshold (p = 0.02). Stepwise linear regression detected local spinal cord atrophy associated with weakness in the corresponding muscle territory, i.e. C4 level for deltoid and C7 level for hand muscles. In conclusion, impairment of spinal sensory pathways was detected at an early stage of the disease. Our data also demonstrate an association between muscle deficits and local spinal cord atrophy, suggesting that atrophy is a sensitive biomarker for lower motor neurons degeneration.

  5. Mediodorsal Thalamic Neurons Mirror the Activity of Medial Prefrontal Neurons Responding to Movement and Reinforcement during a Dynamic DNMTP Task.

    Science.gov (United States)

    Miller, Rikki L A; Francoeur, Miranda J; Gibson, Brett M; Mair, Robert G

    2017-01-01

    The mediodorsal nucleus (MD) interacts with medial prefrontal cortex (mPFC) to support learning and adaptive decision-making. MD receives driver (layer 5) and modulatory (layer 6) projections from PFC and is the main source of driver thalamic projections to middle cortical layers of PFC. Little is known about the activity of MD neurons and their influence on PFC during decision-making. We recorded MD neurons in rats performing a dynamic delayed nonmatching to position (dDNMTP) task and compared results to a previous study of mPFC with the same task (Onos et al., 2016). Criterion event-related responses were observed for 22% (254/1179) of neurons recorded in MD, 237 (93%) of which exhibited activity consistent with mPFC response types. More MD than mPFC neurons exhibited responses related to movement (45% vs. 29%) and reinforcement (51% vs. 27%). MD had few responses related to lever presses, and none related to preparation or memory delay, which constituted 43% of event-related activity in mPFC. Comparison of averaged normalized population activity and population response times confirmed the broad similarity of common response types in MD and mPFC and revealed differences in the onset and offset of some response types. Our results show that MD represents information about actions and outcomes essential for decision-making during dDNMTP, consistent with evidence from lesion studies that MD supports reward-based learning and action-selection. These findings support the hypothesis that MD reinforces task-relevant neural activity in PFC that gives rise to adaptive behavior.

  6. eGFP expression under the Uchl1 promoter labels corticospinal motor neurons and a subpopulation of degeneration resistant spinal motor neurons in ALS mouse models

    Science.gov (United States)

    Yasvoina, Marina V.

    Current understanding of basic cellular and molecular mechanisms for motor neuron vulnerability during motor neuron disease initiation and progression is incomplete. The complex cytoarchitecture and cellular heterogeneity of the cortex and spinal cord greatly impedes our ability to visualize, isolate, and study specific neuron populations in both healthy and diseased states. We generated a novel reporter line, the Uchl1-eGFP mouse, in which cortical and spinal components of motor neuron circuitry are genetically labeled with eGFP under the Uchl1 promoter. A series of cellular and anatomical analyses combined with retrograde labeling, molecular marker expression, and electrophysiology were employed to determine identity of eGFP expressing cells in the motor cortex and the spinal cord of novel Uchl1-eGFP reporter mice. We conclude that eGFP is expressed in corticospinal motor neurons (CSMN) in the motor cortex and a subset of S-type alpha and gamma spinal motor neurons (SMN) in the spinal cord. hSOD1G93A and Alsin-/- mice, mouse models for amyotrophic lateral sclerosis (ALS), were bred to Uchl1-eGFP reporter mouse line to investigate the pathophysiology and underlying mechanisms of CSMN degeneration in vivo. Evidence suggests early and progressive degeneration of CSMN and SMN in the hSOD1G93A transgenic mice. We show an early increase of autophagosome formation in the apical dendrites of vulnerable CSMN in hSOD1G93A-UeGFP mice, which is localized to the apical dendrites. In addition, labeling S-type alpha and gamma SMN in the hSOD1G93A-UeGFP mice provide a unique opportunity to study basis of their resistance to degeneration. Mice lacking alsin show moderate clinical phenotype and mild CSMN axon degeneration in the spinal cord, which suggests vulnerability of CSMN. Therefore, we investigated the CSMN cellular and axon defects in aged Alsin-/- mice bred to Uchl1-eGFP reporter mouse line. We show that while CSMN are preserved and lack signs of degeneration, CSMN axons

  7. Calcineurin Dysregulation Underlies Spinal Cord Injury-Induced K+Channel Dysfunction in DRG Neurons.

    Science.gov (United States)

    Zemel, Benjamin M; Muqeem, Tanziyah; Brown, Eric V; Goulão, Miguel; Urban, Mark W; Tymanskyj, Stephen R; Lepore, Angelo C; Covarrubias, Manuel

    2017-08-23

    Dysfunction of the fast-inactivating Kv3.4 potassium current in dorsal root ganglion (DRG) neurons contributes to the hyperexcitability associated with persistent pain induced by spinal cord injury (SCI). However, the underlying mechanism is not known. In light of our previous work demonstrating modulation of the Kv3.4 channel by phosphorylation, we investigated the role of the phosphatase calcineurin (CaN) using electrophysiological, molecular, and imaging approaches in adult female Sprague Dawley rats. Pharmacological inhibition of CaN in small-diameter DRG neurons slowed repolarization of the somatic action potential (AP) and attenuated the Kv3.4 current. Attenuated Kv3.4 currents also exhibited slowed inactivation. We observed similar effects on the recombinant Kv3.4 channel heterologously expressed in Chinese hamster ovary cells, supporting our findings in DRG neurons. Elucidating the molecular basis of these effects, mutation of four previously characterized serines within the Kv3.4 N-terminal inactivation domain eliminated the effects of CaN inhibition on the Kv3.4 current. SCI similarly induced concurrent Kv3.4 current attenuation and slowing of inactivation. Although there was little change in CaN expression and localization after injury, SCI induced upregulation of the native regulator of CaN 1 (RCAN1) in the DRG at the transcript and protein levels. Consistent with CaN inhibition resulting from RCAN1 upregulation, overexpression of RCAN1 in naive DRG neurons recapitulated the effects of pharmacological CaN inhibition on the Kv3.4 current and the AP. Overall, these results demonstrate a novel regulatory pathway that links CaN, RCAN1, and Kv3.4 in DRG neurons. Dysregulation of this pathway might underlie a peripheral mechanism of pain sensitization induced by SCI. SIGNIFICANCE STATEMENT Pain sensitization associated with spinal cord injury (SCI) involves poorly understood maladaptive modulation of neuronal excitability. Although central mechanisms have

  8. Organization of left–right coordination of neuronal activity in the mammalian spinal cord: Insights from computational modelling

    Science.gov (United States)

    Shevtsova, Natalia A; Talpalar, Adolfo E; Markin, Sergey N; Harris-Warrick, Ronald M; Kiehn, Ole; Rybak, Ilya A

    2015-01-01

    Different locomotor gaits in mammals, such as walking or galloping, are produced by coordinated activity in neuronal circuits in the spinal cord. Coordination of neuronal activity between left and right sides of the cord is provided by commissural interneurons (CINs), whose axons cross the midline. In this study, we construct and analyse two computational models of spinal locomotor circuits consisting of left and right rhythm generators interacting bilaterally via several neuronal pathways mediated by different CINs. The CIN populations incorporated in the models include the genetically identified inhibitory (V0D) and excitatory (V0V) subtypes of V0 CINs and excitatory V3 CINs. The model also includes the ipsilaterally projecting excitatory V2a interneurons mediating excitatory drive to the V0V CINs. The proposed network architectures and CIN connectivity allow the models to closely reproduce and suggest mechanistic explanations for several experimental observations. These phenomena include: different speed-dependent contributions of V0D and V0V CINs and V2a interneurons to left–right alternation of neural activity, switching gaits between the left–right alternating walking-like activity and the left–right synchronous hopping-like pattern in mutants lacking specific neuron classes, and speed-dependent asymmetric changes of flexor and extensor phase durations. The models provide insights into the architecture of spinal network and the organization of parallel inhibitory and excitatory CIN pathways and suggest explanations for how these pathways maintain alternating and synchronous gaits at different locomotor speeds. The models propose testable predictions about the neural organization and operation of mammalian locomotor circuits. Key points Coordination of neuronal activity between left and right sides of the mammalian spinal cord is provided by several sets of commissural interneurons (CINs) whose axons cross the midline. Genetically identified inhibitory V

  9. The Cellular Composition and Glia-Neuron Ratio in the Spinal Cord of a Human and a Nonhuman Primate: Comparison With Other Species and Brain Regions.

    Science.gov (United States)

    Bahney, Jami; von Bartheld, Christopher S

    2018-04-01

    The cellular composition of brains shows largely conserved, gradual evolutionary trends between species. In the primate spinal cord, however, the glia-neuron ratio was reported to be greatly increased over that in the rodent spinal cord. Here, we re-examined the cellular composition of the spinal cord of one human and one nonhuman primate species by employing two different counting methods, the isotropic fractionator and stereology. We also determined whether segmental differences in cellular composition, possibly reflecting increased fine motor control of the upper extremities, may explain a sharply increased glia-neuron ratio in primates. In the cynomolgus monkey spinal cord, the isotropic fractionator and stereology yielded 206-275 million cells, of which 13.3-25.1% were neurons (28-69 million). Stereological estimates yielded 21.1% endothelial cells and 65.5% glial cells (glia-neuron ratio of 4.9-5.6). In human spinal cords, the isotropic fractionator and stereology generated estimates of 1.5-1.7 billion cells and 197-222 million neurons (13.4% neurons, 12.2% endothelial cells, 74.8% glial cells), and a glia-neuron ratio of 5.6-7.1, with estimates of neuron numbers in the human spinal cord based on morphological criteria. The non-neuronal to neuron ratios in human and cynomolgus monkey spinal cords were 6.5 and 3.2, respectively, suggesting that previous reports overestimated this ratio. We did not find significant segmental differences in the cellular composition between cervical, thoracic and lumbar levels. When compared with brain regions, the spinal cord showed gradual increases of the glia-neuron ratio with increasing brain mass, similar to the cerebral cortex and the brainstem. Anat Rec, 301:697-710, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. Signaling pathways involved in HSP32 induction by hyperbaric oxygen in rat spinal neurons

    Directory of Open Access Journals (Sweden)

    Guoyang Huang

    2016-12-01

    Full Text Available Spinal cord injury (SCI is a debilitating disease, effective prevention measures are in desperate need. Our previous work found that hyperbaric oxygen (HBO preconditioning significantly protected rats from SCI after stimulated diving, and in vitro study further testified that HBO protected primary cultured rat spinal neurons from oxidative insult and oxygen glucose deprivation injury via heat shock protein (HSP 32 induction. In this study, underlying molecular mechanisms were further investigated. The results showed that a single exposure to HBO significantly increased intracellular levels of reactive oxygen species (ROS and nitric oxide (NO and activated MEK1/2, ERK1/2, p38 MAPK, CREB, Bach1 and Nrf2. The induction of HSP32 by HBO was significantly reversed by pretreatment neurons with ROS scavenger N-Acetyl-L-cysteine, p38 MAPK inhibitor or Nrf2 gene knockdown, enhanced by MEK1/2 inhibitors or gene knockdown but not by ERK1/2 inhibitor. CREB knockdown did not change the expression of HSP32 induced by HBO. N-Acetyl-L-cysteine significantly inhibited the activation of MEK1/2, ERK1/2, p38 MAPK, and Nrf2. Activation of Nrf2 was significantly inhibited by p38 MAPK inhibitor and the nuclear export of Bach1 was significantly enhanced by MEK1/2 inhibitor. The results demonstrated that HBO induces HSP32 expression through a ROS/p38 MAPK/Nrf2 pathway and the MEK1/2/Bach1 pathway contributes to negative regulation in the process. More importantly, as we know, this is the first study to delineate that ERK1/2 is not the only physiological substrates of MEK1/2.

  11. Orexin-A modulates excitatory synaptic transmission and neuronal excitability in the spinal cord substantia gelatinosa.

    Science.gov (United States)

    Jeon, Younghoon; Park, Ki Bum; Pervin, Rokeya; Kim, Tae Wan; Youn, Dong-ho

    2015-09-14

    Although intrathecal orexin-A has been known to be antinociceptive in various pain models, the role of orexin-A in antinociception is not well characterized. In the present study, we examined whether orexin-A modulates primary afferent fiber-mediated or spontaneous excitatory synaptic transmission using transverse spinal cord slices with attached dorsal root. Bath-application of orexin-A (100nM) reduced the amplitude of excitatory postsynaptic currents (EPSCs) evoked by electrical stimulation of Aδ- or C-primary afferent fibers. The magnitude of reduction was much larger for EPSCs evoked by polysynaptic C-fibers than polysynaptic Aδ-fibers, whereas it was similar in EPSCs evoked by monosynaptic Aδ- or C-fibers. SB674042, an orexin-1 receptor antagonist, but not EMPA, an orexin-2 receptor antagonist, significantly inhibited the orexin-A-induced reduction in EPSC amplitude from mono- or polysynaptic Aδ-fibers, as well as from mono- or polysynaptic C-fibers. Furthermore, orexin-A significantly increased the frequency of spontaneous EPSCs but not the amplitude. This increase was almost completely blocked by both SB674042 and EMPA. On the other hand, orexin-A produced membrane oscillations and inward currents in the SG neurons that were partially or completely inhibited by SB674042 or EMPA, respectively. Thus, this study suggests that the spinal actions of orexin-A underlie orexin-A-induced antinociceptive effects via different subtypes of orexin receptors. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. [Dendritic projections from meridian-related motoneurons to sympathic preganglion neurons in the spinal cord of rats].

    Science.gov (United States)

    Liu, Ke; Duan, Wan-Ru; Ma, Chao; Xie, Yi-Kuan

    2013-12-01

    Previous studies indicated a close involvement of reflex activities of motoneurons in the spinal cord in the mechanism of meridian phenomena. The present study was designed to investigate the dendrite projections of meridian-related motoneurons among the motoneurons and sympathetic preganglionic neurons in the spinal cord. A total of 41 Sprague-Dawley rats were used in the present study. Cholera toxin B-subunit conjugated horseradish peroxidase (CB-HRP) containing 1.0% HRP was respectively injected to acupoint "Chengman" (ST 20), "Liangmen" (ST 21), "Guanmen" (ST 22), "Taiyi" (ST 23), "Huaroumen" (ST 24), "Tianshu" (ST 25) and "Wailing" (ST 26) of the Stomach Meridian, and "Ganshu" (BL 18), "Danshu" (BL 19), "Pishu" (BL 20), "Weishu" (BL 21) and "Sanjiaoshu" (BL 22) of the Bladder Meridian, and "Daimai" (GB 26), "Wushu" (GB 27), "Weidao" (GB 28), "Juliao" (GB 29), "Huantiao" (GB 30), "Fengshi" (GB 31), "Zhongdu" (GB 32), "Xiyangguan" (GB 33) and "Yanglingquan" (GB 34) of the Gallbladder Meridian (for labeling preganglionic neurons), and the celiac ganglion and superior mesenteric ganglion for labeling sympathetic preganglionic neurons. Three days after injection, the animals anesthetized were transcardia-cally perfused with 1.5% paraformaldehyde, the spinal cord was removed to be fixed routinely and then cut into sections for observing the labeled cells under microscope. In the ipsilateral ventral horn of the spinal cord, the motoneurons retrogradely labeled by CB-HRP formed dendritic projections oriented only to those motoneurons innervating the same meridian. In the longitudinal sections of spinal cord, the labeled motoneurons formed a bead-like column with a prominent network of longitudinal dendrites connecting the motoneurons innervating acupoints from the same meridian. In the transverse sections of spinal cord, two groups of dendrites from the labeled motoneurons projected to the identified sympathetic preganglionic regions: one group extended dorsolateraly

  13. Hippocampal neurons respond uniquely to topographies of various sizes and shapes

    International Nuclear Information System (INIS)

    Fozdar, David Y; Chen Shaochen; Lee, Jae Young; Schmidt, Christine E

    2010-01-01

    A number of studies have investigated the behavior of neurons on microfabricated topography for the purpose of developing interfaces for use in neural engineering applications. However, there have been few studies simultaneously exploring the effects of topographies having various feature sizes and shapes on axon growth and polarization in the first 24 h. Accordingly, here we investigated the effects of arrays of lines (ridge grooves) and holes of microscale (∼2 μm) and nanoscale (∼300 nm) dimensions, patterned in quartz (SiO 2 ), on the (1) adhesion, (2) axon establishment (polarization), (3) axon length, (4) axon alignment and (5) cell morphology of rat embryonic hippocampal neurons, to study the response of the neurons to feature dimension and geometry. Neurons were analyzed using optical and scanning electron microscopy. The topographies were found to have a negligible effect on cell attachment but to cause a marked increase in axon polarization, occurring more frequently on sub-microscale features than on microscale features. Neurons were observed to form longer axons on lines than on holes and smooth surfaces; axons were either aligned parallel or perpendicular to the line features. An analysis of cell morphology indicated that the surface features impacted the morphologies of the soma, axon and growth cone. The results suggest that incorporating microscale and sub-microscale topographies on biomaterial surfaces may enhance the biomaterials' ability to modulate nerve development and regeneration.

  14. Neuronal calcium-binding proteins 1/2 localize to dorsal root ganglia and excitatory spinal neurons and are regulated by nerve injury

    DEFF Research Database (Denmark)

    Zhang, Ming Dong; Tortoriello, Giuseppe; Hsueh, Brian

    2014-01-01

    /2 neurons are much more abundant in DRGs than the Ca2+-binding proteins (parvalbumin, calbindin, calretinin, and secretagogin) studied to date. In the spinal cord, the NECAB1/2 distribution is mainly complementary. NECAB1 labels interneurons and a plexus of processes in superficial layers of the dorsal horn......Neuronal calcium (Ca2+)-binding proteins 1 and 2 (NECAB1/2) are members of the phylogenetically conserved EF-hand Ca2+-binding protein superfamily. To date, NECABs have been explored only to a limited extent and, so far, not at all at the spinal level. Here, we describe the distribution, phenotype....... In the dorsal horn, most NECAB1/2 neurons are glutamatergic. Both NECAB1/2 are transported into dorsal roots and peripheral nerves. Peripheral nerve injury reduces NECAB2, but not NECAB1, expression in DRG neurons. Our study identifies NECAB1/2 as abundant Ca2+-binding proteins in pain-related DRG neurons...

  15. Motor Neuron Gene Therapy: Lessons from Spinal Muscular Atrophy for Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Tosolini, Andrew P; Sleigh, James N

    2017-01-01

    Spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS) are severe nervous system diseases characterized by the degeneration of lower motor neurons. They share a number of additional pathological, cellular, and genetic parallels suggesting that mechanistic and clinical insights into one disorder may have value for the other. While there are currently no clinical ALS gene therapies, the splice-switching antisense oligonucleotide, nusinersen, was recently approved for SMA. This milestone was achieved through extensive pre-clinical research and patient trials, which together have spawned fundamental insights into motor neuron gene therapy. We have thus tried to distil key information garnered from SMA research, in the hope that it may stimulate a more directed approach to ALS gene therapy. Not only must the type of therapeutic (e.g., antisense oligonucleotide vs. viral vector) be sensibly selected, but considerable thought must be applied to the where , which , what , and when in order to enhance treatment benefit: to where (cell types and tissues) must the drug be delivered and how can this be best achieved? Which perturbed pathways must be corrected and can they be concurrently targeted? What dosing regime and concentration should be used? When should medication be administered? These questions are intuitive, but central to identifying and optimizing a successful gene therapy. Providing definitive solutions to these quandaries will be difficult, but clear thinking about therapeutic testing is necessary if we are to have the best chance of developing viable ALS gene therapies and improving upon early generation SMA treatments.

  16. Motor Neuron Gene Therapy: Lessons from Spinal Muscular Atrophy for Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Andrew P. Tosolini

    2017-12-01

    Full Text Available Spinal muscular atrophy (SMA and amyotrophic lateral sclerosis (ALS are severe nervous system diseases characterized by the degeneration of lower motor neurons. They share a number of additional pathological, cellular, and genetic parallels suggesting that mechanistic and clinical insights into one disorder may have value for the other. While there are currently no clinical ALS gene therapies, the splice-switching antisense oligonucleotide, nusinersen, was recently approved for SMA. This milestone was achieved through extensive pre-clinical research and patient trials, which together have spawned fundamental insights into motor neuron gene therapy. We have thus tried to distil key information garnered from SMA research, in the hope that it may stimulate a more directed approach to ALS gene therapy. Not only must the type of therapeutic (e.g., antisense oligonucleotide vs. viral vector be sensibly selected, but considerable thought must be applied to the where, which, what, and when in order to enhance treatment benefit: to where (cell types and tissues must the drug be delivered and how can this be best achieved? Which perturbed pathways must be corrected and can they be concurrently targeted? What dosing regime and concentration should be used? When should medication be administered? These questions are intuitive, but central to identifying and optimizing a successful gene therapy. Providing definitive solutions to these quandaries will be difficult, but clear thinking about therapeutic testing is necessary if we are to have the best chance of developing viable ALS gene therapies and improving upon early generation SMA treatments.

  17. AMPA Receptor Phosphorylation and Synaptic Colocalization on Motor Neurons Drive Maladaptive Plasticity below Complete Spinal Cord Injury.

    Science.gov (United States)

    Huie, J Russell; Stuck, Ellen D; Lee, Kuan H; Irvine, Karen-Amanda; Beattie, Michael S; Bresnahan, Jacqueline C; Grau, James W; Ferguson, Adam R

    2015-01-01

    Clinical spinal cord injury (SCI) is accompanied by comorbid peripheral injury in 47% of patients. Human and animal modeling data have shown that painful peripheral injuries undermine long-term recovery of locomotion through unknown mechanisms. Peripheral nociceptive stimuli induce maladaptive synaptic plasticity in dorsal horn sensory systems through AMPA receptor (AMPAR) phosphorylation and trafficking to synapses. Here we test whether ventral horn motor neurons in rats demonstrate similar experience-dependent maladaptive plasticity below a complete SCI in vivo. Quantitative biochemistry demonstrated that intermittent nociceptive stimulation (INS) rapidly and selectively increases AMPAR subunit GluA1 serine 831 phosphorylation and localization to synapses in the injured spinal cord, while reducing synaptic GluA2. These changes predict motor dysfunction in the absence of cell death signaling, suggesting an opportunity for therapeutic reversal. Automated confocal time-course analysis of lumbar ventral horn motor neurons confirmed a time-dependent increase in synaptic GluA1 with concurrent decrease in synaptic GluA2. Optical fractionation of neuronal plasma membranes revealed GluA2 removal from extrasynaptic sites on motor neurons early after INS followed by removal from synapses 2 h later. As GluA2-lacking AMPARs are canonical calcium-permeable AMPARs (CP-AMPARs), their stimulus- and time-dependent insertion provides a therapeutic target for limiting calcium-dependent dynamic maladaptive plasticity after SCI. Confirming this, a selective CP-AMPAR antagonist protected against INS-induced maladaptive spinal plasticity, restoring adaptive motor responses on a sensorimotor spinal training task. These findings highlight the critical involvement of AMPARs in experience-dependent spinal cord plasticity after injury and provide a pharmacologically targetable synaptic mechanism by which early postinjury experience shapes motor plasticity.

  18. Morphometric analysis of neurons from the marginal and substantia gelatinosa layers of human spinal cord: Classification according to laminar organization

    Directory of Open Access Journals (Sweden)

    Milošević Nebojša T.

    2005-01-01

    Full Text Available The main goal of morphometric analysis of neuronal images, except for getting information about their geometry and dendritic branching patterns, is their classification based on laminar organization. The majority of contemporary techniques for image analysis are based on the application of fractal theory, which has some limitations on results analysis. For that reasons, the new, mostly nonfractal techniques for image analysis had been designed in the past few years. This study shows the analysis of morphometry of the human spinal cord neurons from the marginal (lamina I and substantia gelatinosa (laminae I-II. For the analysis of neuron images two techniques of morphometric analysis were used: box-counting method as a mainly used technique for fractal analysis, and circle-counting method as a newly designed technique for measuring the length of dendrites. The use of these methods for neurons of the mentioned regions of human spinal cord showed that circlecounting method had given more accurate results than fractal analysis method. When the proposed method was used for the analysis of neuronal images, it was possible to classify neurons according to their laminar position.

  19. Identification of sodium channel isoforms that mediate action potential firing in lamina I/II spinal cord neurons

    Directory of Open Access Journals (Sweden)

    Smith Paula L

    2011-09-01

    Full Text Available Abstract Background Voltage-gated sodium channels play key roles in acute and chronic pain processing. The molecular, biophysical, and pharmacological properties of sodium channel currents have been extensively studied for peripheral nociceptors while the properties of sodium channel currents in dorsal horn spinal cord neurons remain incompletely understood. Thus far, investigations into the roles of sodium channel function in nociceptive signaling have primarily focused on recombinant channels or peripheral nociceptors. Here, we utilize recordings from lamina I/II neurons withdrawn from the surface of spinal cord slices to systematically determine the functional properties of sodium channels expressed within the superficial dorsal horn. Results Sodium channel currents within lamina I/II neurons exhibited relatively hyperpolarized voltage-dependent properties and fast kinetics of both inactivation and recovery from inactivation, enabling small changes in neuronal membrane potentials to have large effects on intrinsic excitability. By combining biophysical and pharmacological channel properties with quantitative real-time PCR results, we demonstrate that functional sodium channel currents within lamina I/II neurons are predominantly composed of the NaV1.2 and NaV1.3 isoforms. Conclusions Overall, lamina I/II neurons express a unique combination of functional sodium channels that are highly divergent from the sodium channel isoforms found within peripheral nociceptors, creating potentially complementary or distinct ion channel targets for future pain therapeutics.

  20. Spinal cord-specific deletion of the glutamate transporter GLT1 causes motor neuron death in mice.

    Science.gov (United States)

    Sugiyama, Kaori; Tanaka, Kohichi

    2018-03-04

    Amyotrophic lateral sclerosis (ALS) is a chronic neurodegenerative disorder characterized by the selective loss of motor neurons. The precise mechanisms that cause the selective death of motor neurons remain unclear, but a growing body of evidence suggests that glutamate-mediated excitotoxicity has been considered to play an important role in the mechanisms of motor neuron degeneration in ALS. Reductions in glutamate transporter GLT1 have been reported in animal models of ALS and the motor cortex and spinal cord of ALS patients. However, it remains unknown whether the reduction in GLT1 has a primary role in the induction of motor neuron degeneration in ALS. Here, we generated conditional knockout mice that lacked GLT1 specifically in the spinal cord by crossing floxed-GLT1 mice and Hoxb8-Cre mice. Hoxb8-Cre/GLT1 flox/flox mice showed motor deficits and motor neuron loss. Thus, loss of the glial glutamate transporter GLT1 is sufficient to cause motor neuron death in mice. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Protective effects of two constituents of Chinese herbs on spinal motor neurons from embryonic rats with hypoxia injury.

    Science.gov (United States)

    Chen, Jian-Feng; Fan, Jian; Tian, Xiao-Wu; Tang, Tian-Si

    2012-01-01

    Neuroprotective agents are becoming significant tools in the repair of central nervous system injuries. In this study, we determined whether ginkgolides (Gin, extract of GinkgoBiloba) and Acanthopanax senticosus saponins (ASS, flavonoids extracted from Acanthopanax herbal preparations) have protective effects on rat spinal cords exposed to anoxia and we explored the mechanisms that underlie the protective effects. Spinal motor neurons (SMNs) from rat spinal cords were obtained and divided into five groups with 10 wells in each group. In control group, SMNs suffered no injury under normal oxygen; in hypoxia- inducible (HI) group, SMNs suffered injury from hypoxia; in Gin group, 37.5µg/ml Gin were used before 24 hrs of hypoxia; in ASS group, 50µg/ml ASS were used before 24 hrs of hypoxia;in glial cell-lined derived neurotrophic factor (GDNF) group, 0.1µg/ml GDNF were used before 24 hrs of hypoxia. Changes in morphology, neuron viability, and lactate dehydrogenase (LDH) release were observed. In addition, the expression of HIF-1α induced by hypoxia was measured. The neuronal viability in the Gin, ASS, and GDNF pretreated groups was higher than that in the HI group (P0.05). The quantity of LDH released in the three pretreated groups was lower than that in the HI group (Phypoxic neurons.

  2. Non-aggregating tau phosphorylation by cyclin-dependent kinase 5 contributes to motor neuron degeneration in spinal muscular atrophy.

    Science.gov (United States)

    Miller, Nimrod; Feng, Zhihua; Edens, Brittany M; Yang, Ben; Shi, Han; Sze, Christie C; Hong, Benjamin Taige; Su, Susan C; Cantu, Jorge A; Topczewski, Jacek; Crawford, Thomas O; Ko, Chien-Ping; Sumner, Charlotte J; Ma, Long; Ma, Yong-Chao

    2015-04-15

    Mechanisms underlying motor neuron degeneration in spinal muscular atrophy (SMA), the leading inherited cause of infant mortality, remain largely unknown. Many studies have established the importance of hyperphosphorylation of the microtubule-associated protein tau in various neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. However, tau phosphorylation in SMA pathogenesis has yet to be investigated. Here we show that tau phosphorylation on serine 202 (S202) and threonine 205 (T205) is increased significantly in SMA motor neurons using two SMA mouse models and human SMA patient spinal cord samples. Interestingly, phosphorylated tau does not form aggregates in motor neurons or neuromuscular junctions (NMJs), even at late stages of SMA disease, distinguishing it from other tauopathies. Hyperphosphorylation of tau on S202 and T205 is mediated by cyclin-dependent kinase 5 (Cdk5) in SMA disease condition, because tau phosphorylation at these sites is significantly reduced in Cdk5 knock-out mice; genetic knock-out of Cdk5 activating subunit p35 in an SMA mouse model also leads to reduced tau phosphorylation on S202 and T205 in the SMA;p35(-/-) compound mutant mice. In addition, expression of the phosphorylation-deficient tauS202A,T205A mutant alleviates motor neuron defects in a zebrafish SMA model in vivo and mouse motor neuron degeneration in culture, whereas expression of phosphorylation-mimetic tauS202E,T205E promotes motor neuron defects. More importantly, genetic knock-out of tau in SMA mice rescues synapse stripping on motor neurons, NMJ denervation, and motor neuron degeneration in vivo. Altogether, our findings suggest a novel mechanism for SMA pathogenesis in which hyperphosphorylation of non-aggregating tau by Cdk5 contributes to motor neuron degeneration. Copyright © 2015 the authors 0270-6474/15/356038-13$15.00/0.

  3. Reduced sensory synaptic excitation impairs motor neuron function via Kv2.1 in spinal muscular atrophy.

    Science.gov (United States)

    Fletcher, Emily V; Simon, Christian M; Pagiazitis, John G; Chalif, Joshua I; Vukojicic, Aleksandra; Drobac, Estelle; Wang, Xiaojian; Mentis, George Z

    2017-07-01

    Behavioral deficits in neurodegenerative diseases are often attributed to the selective dysfunction of vulnerable neurons via cell-autonomous mechanisms. Although vulnerable neurons are embedded in neuronal circuits, the contributions of their synaptic partners to disease process are largely unknown. Here we show that, in a mouse model of spinal muscular atrophy (SMA), a reduction in proprioceptive synaptic drive leads to motor neuron dysfunction and motor behavior impairments. In SMA mice or after the blockade of proprioceptive synaptic transmission, we observed a decrease in the motor neuron firing that could be explained by the reduction in the expression of the potassium channel Kv2.1 at the surface of motor neurons. Chronically increasing neuronal activity pharmacologically in vivo led to a normalization of Kv2.1 expression and an improvement in motor function. Our results demonstrate a key role of excitatory synaptic drive in shaping the function of motor neurons during development and the contribution of its disruption to a neurodegenerative disease.

  4. Inhibition of apoptosis blocks human motor neuron cell death in a stem cell model of spinal muscular atrophy.

    Directory of Open Access Journals (Sweden)

    Dhruv Sareen

    Full Text Available Spinal muscular atrophy (SMA is a genetic disorder caused by a deletion of the survival motor neuron 1 gene leading to motor neuron loss, muscle atrophy, paralysis, and death. We show here that induced pluripotent stem cell (iPSC lines generated from two Type I SMA subjects-one produced with lentiviral constructs and the second using a virus-free plasmid-based approach-recapitulate the disease phenotype and generate significantly fewer motor neurons at later developmental time periods in culture compared to two separate control subject iPSC lines. During motor neuron development, both SMA lines showed an increase in Fas ligand-mediated apoptosis and increased caspase-8 and-3 activation. Importantly, this could be mitigated by addition of either a Fas blocking antibody or a caspase-3 inhibitor. Together, these data further validate this human stem cell model of SMA, suggesting that specific inhibitors of apoptotic pathways may be beneficial for patients.

  5. The opioid receptor antagonist, naloxone, protects spinal motor neurons in a murine model of alphavirus encephalomyelitis

    Science.gov (United States)

    Prow, Natalie A.; Irani, David N.

    2007-01-01

    Spread of neuroadapted Sindbis virus (NSV) to motor neurons (MN) of the spinal cord (SC) causes severe hind limb weakness in C57BL/6 mice and models the paralysis that can accompany alphavirus and flavivirus encephalomyelitis in humans. The fate of spinal MN dictates the severity of NSV-induced paralysis, and recent data suggest that MN damage can occur indirectly via the actions of activated microglial cells. Because the opioid receptor antagonist, naloxone (NAL), blocks microglial-mediated neurodegeneration in other models, we examined its effects during NSV infection. Drug treatment prevented paralysis and enhanced the survival of MN without altering NSV tropism, replication, or clearance from SC tissue. Further studies showed that NAL most effectively inhibited paralysis in a 72-hour window after NSV challenge, suggesting that the drug inhibits an early event in SC pathogenesis. Histochemical studies demonstrated that NAL blocked early microglial activation in SC tissue sections, and protein assays showed that the early induction of pathogenic IL-1β was blunted in SC homogenates. Finally, loss of glutamate transporter-1 (GLT-1) expression in SC, an astrocyte glutamate reuptake protein responsible for lowering toxic extracellular levels of glutamate and preventing MN damage, was reversed by NAL treatment. This GLT-1 loss proved to be highly IL-1β-dependent. Taken together, these data suggest that NAL is neuroprotective in the SC by inhibiting microglial activation that, in turn, maintains normal astrocyte glutamate homeostasis. We propose that drugs targeting such microglial responses may have therapeutic benefit in humans with related viral infections. PMID:17459376

  6. Activation-Dependent Rapid Postsynaptic Clustering of Glycine Receptors in Mature Spinal Cord Neurons

    Science.gov (United States)

    Eto, Kei; Murakoshi, Hideji; Watanabe, Miho; Hirata, Hiromi; Moorhouse, Andrew J.; Ishibashi, Hitoshi

    2017-01-01

    Abstract Inhibitory synapses are established during development but continue to be generated and modulated in strength in the mature nervous system. In the spinal cord and brainstem, presynaptically released inhibitory neurotransmitter dominantly switches from GABA to glycine during normal development in vivo. While presynaptic mechanisms of the shift of inhibitory neurotransmission are well investigated, the contribution of postsynaptic neurotransmitter receptors to this shift is not fully elucidated. Synaptic clustering of glycine receptors (GlyRs) is regulated by activation-dependent depolarization in early development. However, GlyR activation induces hyperpolarization after the first postnatal week, and little is known whether and how presynaptically released glycine regulates postsynaptic receptors in a depolarization-independent manner in mature developmental stage. Here we developed spinal cord neuronal culture of rodents using chronic strychnine application to investigate whether initial activation of GlyRs in mature stage could change postsynaptic localization of GlyRs. Immunocytochemical analyses demonstrate that chronic blockade of GlyR activation until mature developmental stage resulted in smaller clusters of postsynaptic GlyRs that could be enlarged upon receptor activation for 1 h in the mature stage. Furthermore, live cell-imaging techniques show that GlyR activation decreases its lateral diffusion at synapses, and this phenomenon is dependent on PKC, but neither Ca2+ nor CaMKII activity. These results suggest that the GlyR activation can regulate receptor diffusion and cluster size at inhibitory synapses in mature stage, providing not only new insights into the postsynaptic mechanism of shifting inhibitory neurotransmission but also the inhibitory synaptic plasticity in mature nervous system. PMID:28197549

  7. Astrocyte-produced miR-146a as a mediator of motor neuron loss in spinal muscular atrophy.

    Science.gov (United States)

    Sison, Samantha L; Patitucci, Teresa N; Seminary, Emily R; Villalon, Eric; Lorson, Christian L; Ebert, Allison D

    2017-09-01

    Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, is caused by the loss of the survival motor neuron-1 (SMN1) gene, which leads to motor neuron loss, muscle atrophy, respiratory distress, and death. Motor neurons exhibit the most profound loss, but the mechanisms underlying disease pathogenesis are not fully understood. Recent evidence suggests that motor neuron extrinsic influences, such as those arising from astrocytes, contribute to motor neuron malfunction and loss. Here we investigated both loss-of-function and toxic gain-of-function astrocyte mechanisms that could play a role in SMA pathology. We had previously found that glial derived neurotrophic factor (GDNF) is reduced in SMA astrocytes. However, reduced GDNF expression does not play a major role in SMA pathology as viral-mediated GDNF re-expression did not improve astrocyte function or motor neuron loss. In contrast, we found that SMA astrocytes increased microRNA (miR) production and secretion compared to control astrocytes, suggesting potential toxic gain-of-function properties. Specifically, we found that miR-146a was significantly upregulated in SMA induced pluripotent stem cell (iPSC)-derived astrocytes and SMNΔ7 mouse spinal cord. Moreover, increased miR-146a was sufficient to induce motor neuron loss in vitro, whereas miR-146a inhibition prevented SMA astrocyte-induced motor neuron loss. Together, these data indicate that altered astrocyte production of miR-146a may be a contributing factor in astrocyte-mediated SMA pathology. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Severe motor neuron degeneration in the spinal cord of the Tg2576 mouse model of Alzheimer disease.

    Science.gov (United States)

    Seo, Ji-Seon; Leem, Yea-Hyun; Lee, Kang-Woo; Kim, Seung-Woo; Lee, Ja-Kyeong; Han, Pyung-Lim

    2010-01-01

    The transgenic mouse Tg2576 is widely used as a murine model of Alzheimer's disease (AD) and exhibits plaque pathogenesis in the brain and progressive memory impairments. Here we report that Tg2576 mice also have severe spinal cord deficits. At 10 months of age, Tg2576 mice showed a severe defect in the hindlimb extension reflex test and abnormal body trembling and hindlimb tremors when suspended by the tail. The frequency and severity of these abnormalities were overt at 10 months of age and became gradually worsened. On the foot-printing analysis, Tg2576 mice had shorter and narrower strides than the non-transgenic control. Histological analyses showed that neuronal cells including cholinergic neurons in the lumbar cord of Tg2576 mice were severely reduced in number. At 16 months of age, Tg2576 mice showed high levels of amyloid-beta accumulation in the spinal cord. Consistent with this, Tg2576 mice showed that lipid peroxidation levels were increased and mitochondrial metabolic activity were significantly reduced in the spinal cord. Administration of curcumin, a natural compound that has antioxidant properties, notably reversed motor function deficits of Tg2576 mice. The enhanced lipid peroxidation and neuronal loss in the lumbar cord was also partially suppressed by curcumin. Electron microscopic analysis revealed that the sciatic nerve fibers were severely reduced in number and were demyelinated in Tg2576 mice, which were partially rescued by curcumin. These results showed that Tg2576 mice display severe degeneration of motor neurons in the spinal cord and associated motor function deficits.

  9. Oxytocin-induced antinociception in the spinal cord is mediated by a subpopulation of glutamatergic neurons in lamina I-II which amplify GABAergic inhibition

    Directory of Open Access Journals (Sweden)

    Schlichter Rémy

    2008-05-01

    Full Text Available Abstract Background Recent evidence suggests that oxytocin (OT, secreted in the superficial spinal cord dorsal horn by descending axons of paraventricular hypothalamic nucleus (PVN neurons, produces antinociception and analgesia. The spinal mechanism of OT is, however, still unclear and requires further investigation. We have used patch clamp recording of lamina II neurons in spinal cord slices and immunocytochemistry in order to identify PVN-activated neurons in the superficial layers of the spinal cord and attempted to determine how this neuronal population may lead to OT-mediated antinociception. Results We show that OT released during PVN stimulation specifically activates a subpopulation of lamina II glutamatergic interneurons which are localized in the most superficial layers of the dorsal horn of the spinal cord (lamina I-II. This OT-specific stimulation of glutamatergic neurons allows the recruitment of all GABAergic interneurons in lamina II which produces a generalized elevation of local inhibition, a phenomenon which might explain the reduction of incoming Aδ and C primary afferent-mediated sensory messages. Conclusion Our results obtained in lamina II of the spinal cord provide the first clear evidence of a specific local neuronal network that is activated by OT release to induce antinociception. This OT-specific pathway might represent a novel and interesting therapeutic target for the management of neuropathic and inflammatory pain.

  10. The Spinal Neurons Exhibit an ON-OFF and OFF-ON Firing Activity Around the Onset of Fictive Scratching Episodes in the Cat

    Directory of Open Access Journals (Sweden)

    Carlos A. Cuellar

    2018-03-01

    Full Text Available In a previous report, we found neurons with ON-OFF and OFF-ON firing activity in the obex reticular formation during scratching. The aim of the present study was to examine whether the spinal neurons also exhibit this type of activity in relation to the “postural stage” of fictive scratching in the cat. We found that the extensor and intermediate scratching neurons exhibit an ON-OFF firing rate; conversely, the flexor neurons show an OFF-ON activity, relative to every scratching episode. These patterns of spiking activity are similar to those found in neurons from the obex reticular formation during scratching. Our findings provide support to the following hypotheses. First, there is a possible functional link between supraspinal and spinal, ON-OFF and OFF-ON neuronal groups. Second, the fictive goal-directed motor action to maintain the fictive “postural stage” of the hindlimb during fictive scratching is associated with the neuronal tonic activity of the OFF-ON spinal neurons, whereas the ON-OFF spinal neurons are associated with an extensor tone that occurred prior the postural stage.

  11. FLIM FRET Visualization of Cdc42 Activation by Netrin-1 in Embryonic Spinal Commissural Neuron Growth Cones.

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    Benjamin Rappaz

    Full Text Available Netrin-1 is an essential extracellular chemoattractant that signals through its receptor DCC to guide commissural axon extension in the embryonic spinal cord. DCC directs the organization of F-actin in growth cones by activating an intracellular protein complex that includes the Rho GTPase Cdc42, a critical regulator of cell polarity and directional migration. To address the spatial distribution of signaling events downstream of netrin-1, we expressed the FRET biosensor Raichu-Cdc42 in cultured embryonic rat spinal commissural neurons. Using FLIM-FRET imaging we detected rapid activation of Cdc42 in neuronal growth cones following application of netrin-1. Investigating the signaling mechanisms that control Cdc42 activation by netrin-1, we demonstrate that netrin-1 rapidly enriches DCC at the leading edge of commissural neuron growth cones and that netrin-1 induced activation of Cdc42 in the growth cone is blocked by inhibiting src family kinase signaling. These findings reveal the activation of Cdc42 in embryonic spinal commissural axon growth cones and support the conclusion that src family kinase activation downstream of DCC is required for Cdc42 activation by netrin-1.

  12. Electrophysiological characterization of spinal neurons in different models of diabetes type 1- and type 2-induced neuropathy in rats.

    Science.gov (United States)

    Schuelert, N; Gorodetskaya, N; Just, S; Doods, H; Corradini, L

    2015-04-16

    Diabetic polyneuropathy (DPN) is a devastating complication of diabetes. The underlying pathogenesis of DPN is still elusive and an effective treatment devoid of side effects presents a challenge. There is evidence that in type-1 and -2 diabetes, metabolic and morphological changes lead to peripheral nerve damage and altered central nociceptive transmission, which may contribute to neuropathic pain symptoms. We characterized the electrophysiological response properties of spinal wide dynamic range (WDR) neurons in three diabetic models. The streptozotocin (STZ) model was used as a drug-induced model of type-1 diabetes, and the BioBreeding/Worcester (BB/Wor) and Zucker diabetic fatty (ZDF) rat models were used for genetic DPN models. Data were compared to the respective control group (BB/Wor diabetic-resistant, Zucker lean (ZL) and saline-injected Wistar rat). Response properties of WDR neurons to mechanical stimulation and spontaneous activity were assessed. We found abnormal response properties of spinal WDR neurons in all diabetic rats but not controls. Profound differences between models were observed. In BB/Wor diabetic rats evoked responses were increased, while in ZDF rats spontaneous activity was increased and in STZ rats mainly after discharges were increased. The abnormal response properties of neurons might indicate differential pathological, diabetes-induced, changes in spinal neuronal transmission. This study shows for the first time that specific electrophysiological response properties are characteristic for certain models of DPN and that these might reflect the diverse and complex symptomatology of DPN in the clinic. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Synaptic NMDA Receptor-Dependent Ca2+ Entry Drives Membrane Potential and Ca2+ Oscillations in Spinal Ventral Horn Neurons

    Science.gov (United States)

    Alpert, Michael H.; Alford, Simon

    2013-01-01

    During vertebrate locomotion, spinal neurons act as oscillators when initiated by glutamate release from descending systems. Activation of NMDA receptors initiates Ca2+-mediated intrinsic membrane potential oscillations in central pattern generator (CPG) neurons. NMDA receptor-dependent intrinsic oscillations require Ca2+-dependent K+ (KCa2) channels for burst termination. However, the location of Ca2+ entry mediating KCa2 channel activation, and type of Ca2+ channel – which includes NMDA receptors and voltage-gated Ca2+ channels (VGCCs) – remains elusive. NMDA receptor-dependent Ca2+ entry necessitates presynaptic release of glutamate, implying a location at active synapses within dendrites, whereas VGCC-dependent Ca2+ entry is not similarly constrained. Where Ca2+ enters relative to KCa2 channels is crucial to information processing of synaptic inputs necessary to coordinate locomotion. We demonstrate that Ca2+ permeating NMDA receptors is the dominant source of Ca2+ during NMDA-dependent oscillations in lamprey spinal neurons. This Ca2+ entry is synaptically located, NMDA receptor-dependent, and sufficient to activate KCa2 channels at excitatory interneuron synapses onto other CPG neurons. Selective blockade of VGCCs reduces whole-cell Ca2+ entry but leaves membrane potential and Ca2+ oscillations unaffected. Furthermore, repetitive oscillations are prevented by fast, but not slow, Ca2+ chelation. Taken together, these results demonstrate that KCa2 channels are closely located to NMDA receptor-dependent Ca2+ entry. The close spatial relationship between NMDA receptors and KCa2 channels provides an intrinsic mechanism whereby synaptic excitation both excites and subsequently inhibits ventral horn neurons of the spinal motor system. This places the components necessary for oscillation generation, and hence locomotion, at glutamatergic synapses. PMID:23646190

  14. Salbutamol inhibits ubiquitin-mediated survival motor neuron protein degradation in spinal muscular atrophy cells.

    Science.gov (United States)

    Harahap, Nur Imma Fatimah; Nurputra, Dian Kesumapramudya; Ar Rochmah, Mawaddah; Shima, Ai; Morisada, Naoya; Takarada, Toru; Takeuchi, Atsuko; Tohyama, Yumi; Yanagisawa, Shinichiro; Nishio, Hisahide

    2015-12-01

    Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder that is currently incurable. SMA is caused by decreased levels of the survival motor neuron protein (SMN), as a result of loss or mutation of SMN1 . Although the SMN1 homolog SMN2 also produces some SMN protein, it does not fully compensate for the loss or dysfunction of SMN1 . Salbutamol, a β2-adrenergic receptor agonist and well-known bronchodilator used in asthma patients, has recently been shown to ameliorate symptoms in SMA patients. However, the precise mechanism of salbutamol action is unclear. We treated SMA fibroblast cells lacking SMN1 and HeLa cells with salbutamol and analyzed SMN2 mRNA and SMN protein levels in SMA fibroblasts, and changes in SMN protein ubiquitination in HeLa cells. Salbutamol increased SMN protein levels in a dose-dependent manner in SMA fibroblast cells lacking SMN1 , though no significant changes in SMN2 mRNA levels were observed. Notably, the salbutamol-induced increase in SMN was blocked by a protein kinase A (PKA) inhibitor and deubiquitinase inhibitor, respectively. Co-immunoprecipitation assay using HeLa cells showed that ubiquitinated SMN levels decreased in the presence of salbutamol, suggesting that salbutamol inhibited ubiquitination. The results of this study suggest that salbutamol may increase SMN protein levels in SMA by inhibiting ubiquitin-mediated SMN degradation via activating β2-adrenergic receptor-PKA pathways.

  15. The motor neuron response to SMN1 deficiency in spinal muscular atrophy.

    Science.gov (United States)

    Kang, Peter B; Gooch, Clifton L; McDermott, Michael P; Darras, Basil T; Finkel, Richard S; Yang, Michele L; Sproule, Douglas M; Chung, Wendy K; Kaufmann, Petra; de Vivo, Darryl C

    2014-05-01

    The purpose of this study was to measure and analyze motor unit number estimation (MUNE) values longitudinally in spinal muscular atrophy (SMA). Sixty-two children with SMA types 2 and 3 were observed prospectively for up to 42 months. Longitudinal electrophysiological data were collected, including compound motor action potential (CMAP), single motor unit action potential (SMUP), and MUNE. Significant motor neuron loss and compensatory collateral reinnervation were noted at baseline. Over time, there was a significant mean increase in MUNE (4.92 units/year, P = 0.009), a mean decrease in SMUP amplitude (-6.32 μV/year, P = 0.10), and stable CMAP amplitude. The unexpected longitudinal results differ from findings in amyotrophic lateral sclerosis studies, perhaps indicating that compensatory processes in SMA involve new motor unit development. A better understanding of the mechanisms of motor unit decline and compensation in SMA is important for assessing novel therapeutic strategies and for providing key insights into disease pathophysiology. Copyright © 2013 Wiley Periodicals, Inc.

  16. ERK-GluR1 phosphorylation in trigeminal spinal subnucleus caudalis neurons is involved in pain associated with dry tongue.

    Science.gov (United States)

    Nakaya, Yuka; Tsuboi, Yoshiyuki; Okada-Ogawa, Akiko; Shinoda, Masamichi; Kubo, Asako; Chen, Jui Yen; Noma, Noboru; Batbold, Dulguun; Imamura, Yoshiki; Sessle, Barry J; Iwata, Koichi

    2016-01-01

    Dry mouth is known to cause severe pain in the intraoral structures, and many dry mouth patients have been suffering from intraoral pain. In development of an appropriate treatment, it is crucial to study the mechanisms underlying intraoral pain associated with dry mouth, yet the detailed mechanisms are not fully understood. To evaluate the mechanisms underlying pain related to dry mouth, the dry-tongue rat model was developed. Hence, the mechanical or heat nocifensive reflex, the phosphorylated extracellular signal-regulated kinase and phosphorylated GluR1-IR immunohistochemistries, and the single neuronal activity were examined in the trigeminal spinal subnucleus caudalis of dry-tongue rats. The head-withdrawal reflex threshold to mechanical, but not heat, stimulation of the tongue was significantly decreased on day 7 after tongue drying. The mechanical, but not heat, responses of trigeminal spinal subnucleus caudalis nociceptive neurons were significantly enhanced in dry-tongue rats compared to sham rats on day 7. The number of phosphorylated extracellular signal-regulated kinase-immunoreactive cells was also significantly increased in the trigeminal spinal subnucleus caudalis following noxious stimulation of the tongue in dry-tongue rats compared to sham rats on day 7. The decrement of the mechanical head-withdrawal reflex threshold (HWT) was reversed during intracisternal administration of the mitogen-activated protein kinase kinase 1 inhibitor, PD98059. The trigeminal spinal subnucleus caudalis neuronal activities and the number of phosphorylated extracellular signal-regulated kinase-immunoreactive cells following noxious mechanical stimulation of dried tongue were also significantly decreased following intracisternal administration of PD98059 compared to vehicle-administrated rats. Increased number of the phosphorylated GluR1-IR cells was observed in the trigeminal spinal subnucleus caudalis of dry-tongue rats, and the number of phosphorylated GluR1-IR cells

  17. Astrocyte-neuron interaction in the substantia gelatinosa of the spinal cord dorsal horn via P2X7 receptor-mediated release of glutamate and reactive oxygen species.

    Science.gov (United States)

    Ficker, Christoph; Rozmer, Katalin; Kató, Erzsébet; Andó, Rómeó D; Schumann, Luisa; Krügel, Ute; Franke, Heike; Sperlágh, Beáta; Riedel, Thomas; Illes, Peter

    2014-10-01

    The substantia gelatinosa (SG) of the spinal cord processes incoming painful information to ascending projection neurons. Whole-cell patch clamp recordings from SG spinal cord slices documented that in a low Ca(2+) /no Mg(2+) (low X(2+) ) external medium adenosine triphosphate (ATP)/dibenzoyl-ATP, Bz-ATP) caused inward current responses, much larger in amplitude than those recorded in a normal X(2+) -containing bath medium. The effect of Bz-ATP was antagonized by the selective P2X7 receptor antagonist A-438079. Neuronal, but not astrocytic Bz-ATP currents were strongly inhibited by a combination of the ionotropic glutamate receptor antagonists AP-5 and CNQX. In fact, all neurons and some astrocytes responded to NMDA, AMPA, and muscimol with inward current, demonstrating the presence of the respective receptors. The reactive oxygen species H2 O2 potentiated the effect of Bz-ATP at neurons but not at astrocytes. Hippocampal CA1 neurons exhibited a behavior similar to, but not identical with SG neurons. Although a combination of AP-5 and CNQX almost abolished the effect of Bz-ATP, H2 O2 was inactive. A Bz-ATP-dependent and A-438079-antagonizable reactive oxygen species production in SG slices was proven by a microelectrode biosensor. Immunohistochemical investigations showed the colocalization of P2X7-immunoreactivity with microglial (Iba1), but not astrocytic (GFAP, S100β) or neuronal (MAP2) markers in the SG. It is concluded that SG astrocytes possess P2X7 receptors; their activation leads to the release of glutamate, which via NMDA- and AMPA receptor stimulation induces cationic current in the neighboring neurons. P2X7 receptors have a very low density under resting conditions but become functionally upregulated under pathological conditions. © 2014 Wiley Periodicals, Inc.

  18. Global gene expression analysis of rodent motor neurons following spinal cord injury associates molecular mechanisms with development of post-injury spasticity

    DEFF Research Database (Denmark)

    Wienecke, Jacob; Westerdahl, Ann-Charlotte; Hultborn, Hans

    2010-01-01

    in this cell population. We adopted a rat tail-spasticity model with a caudal spinal transection that causes a progressive development of spasticity from its onset after two to three weeks until two months post injury. Gene expression changes of fluorescently identified tail motor neurons were studied 21...... of endogenous plateau potentials in motor neurons and the development of spasticity after spinalization. To unravel the molecular mechanisms underlying the increased excitability of motor neurons and the return of plateau potentials below a spinal cord injury we investigated changes in gene expression...... and 60 days post injury. The motor neurons undergo substantial transcriptional regulation in response to injury. The patterns of differential expression show similarities at both time points, though there are 20 % more differentially expressed genes 60 days compared to 21 days post injury. The study...

  19. Tobacco-induced neuronal degeneration via cotinine in rats subjected to experimental spinal cord injury.

    Science.gov (United States)

    Dalgic, Ali; Okay, Onder; Helvacioglu, Fatma; Daglioglu, Ergun; Akdag, Rifat; Take, Gulnur; Belen, Deniz

    2013-05-01

    Cigarette smoke contains over 4000 chemicals including well-characterized toxicants and carcinogens, among which is cotinine. Cotinine is the principal metabolite of nicotine that has adverse affects on the microcirculation via vasoconstriction, hypoxia and the wound-healing cascade. Its impact on spinal cord injury (SCI) has not been investigated yet. The aim of the present study is to investigate the cotinine effect on SCI. 48 male Wistar rats were divided into six groups as follows: sham-control, sham-trauma, vehicle-control, vehicle-trauma, cotinine-control, and cotinine-trauma. Initially, a defined concentration of cotinine blood level was maintained by daily intraperitoneal injection of cotinine for 14 days in the cotinine groups. The concentration was similar to the cotinine dose in the blood level of heavy smokers. Only ethyl alcohol was injected in the vehicle groups during the same period. Then, SCI was performed by a Tator clip. The cotinine groups were compared with rats subjected to vehicle and sham groups by immunohistochemical biomarkers such as glial fibrillary acidic protein (GFAP) and 2,3-cyclic nucleotide 3-phosphodiesterase (CNP) expressions. Electron microscopic examination was also performed. GFAP-positive cells were noted to be localized around degenerated astrocytes. Marked vacuolization with perivascular and perineural edema was seen in the cotinin consumption groups. These findings showed the inhibition of regeneration after SCI. Similarly, vacuolization within myelin layers was noted in the cotinine groups, which was detected through reduced CNP expression. Cotinine, a main metabolite of nicotine, has harmful effects on SCI via GFAP and CNP expression. The findings of the present study support the hypothesis that tobacco causes neuronal degeneration via cotinine. Georg Thieme Verlag KG Stuttgart · New York.

  20. Bitter-sensitive gustatory receptor neuron responds to chemically diverse insect repellents in the common malaria mosquito Anopheles quadrimaculatus

    Science.gov (United States)

    Sparks, Jackson T.; Dickens, Joseph C.

    2016-06-01

    Female mosquitoes feed on blood from animal hosts to obtain nutritional resources used for egg production. These contacts facilitate the spread of harmful human diseases. Chemical repellents are used to disrupt mosquito host-seeking and blood-feeding behaviors; however, little is known about the gustatory sensitivity of mosquitoes to known repellents. Here, we recorded electrical responses from gustatory receptor neurons (GRNs) housed within the labellar sensilla of female Anopheles quadrimaculatus to N,N-diethyl-3-methylbenzamide (DEET), picaridin, IR3535, 2-undecanone, p-menthane-3,8-diol, geraniol, trans-2-hexen-1-ol, quinine, and quinidine. A bitter-sensitive GRN responded to all tested repellents and quinine, a known feeding deterrent. Responses of the bitter-sensitive neuron to quinine and an isomer, quinidine, did not differ. Delayed bursts of electrical activity were observed in response to continuous stimulation with synthetic repellents at high concentrations. Electrophysiological recordings from bitter-sensitive GRNs associated with mosquito gustatory sensilla represent a convenient model to evaluate candidate repellents.

  1. The age factor in axonal repair after spinal cord injury: A focus on neuron-intrinsic mechanisms.

    Science.gov (United States)

    Geoffroy, Cédric G; Meves, Jessica M; Zheng, Binhai

    2017-06-23

    Age is an important consideration for recovery and repair after spinal cord injury. Spinal cord injury is increasingly affecting the middle-aged and aging populations. Despite rapid progress in research to promote axonal regeneration and repair, our understanding of how age can modulate this repair is rather limited. In this review, we discuss the literature supporting the notion of an age-dependent decline in axonal growth after central nervous system (CNS) injury. While both neuron-intrinsic and extrinsic factors are involved in the control of axon growth after injury, here we focus on possible intrinsic mechanisms for this age-dependent decline. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. A 2-center Comparative Study on Tonic Versus Burst Spinal Cord Stimulation: Amount of Responders and Amount of Pain Suppression

    NARCIS (Netherlands)

    Ridder, D.M.D.; Lenders, M.W.P.M.; de Vos, Cecilia Cecilia Clementine; Dijkstra-Scholten, C.R.N.; Wolters, R.R.N.; Vancamp, T.P.T.; Van Looy, P.R.N.; Van Havenbergh, T.M.D.; Vanneste, S.

    2015-01-01

    Introduction: Spinal cord stimulation is a safe and effective procedure applied for medically intractable neuropathic pain and failed back surgery syndrome. Recently, a novel stimulation paradigm was developed, called burst stimulation consisting of intermittent packets of closely spaced

  3. Nerve injury evoked loss of latexin expression in spinal cord neurons contributes to the development of neuropathic pain.

    Directory of Open Access Journals (Sweden)

    Hilmar Nils Kühlein

    Full Text Available Nerve injury leads to sensitization mechanisms in the peripheral and central nervous system which involve transcriptional and post-transcriptional modifications in sensory nerves. To assess protein regulations in the spinal cord after injury of the sciatic nerve in the Spared Nerve Injury model (SNI we performed a proteomic analysis using 2D-difference gel electrophoresis (DIGE technology. Among approximately 2300 protein spots separated on each gel we detected 55 significantly regulated proteins after SNI whereof 41 were successfully identified by MALDI-TOF MS. Out of the proteins which were regulated in the DIGE analyses after SNI we focused on the carboxypeptidase A inhibitor latexin because protease dysfunctions contribute to the development of neuropathic pain. Latexin protein expression was reduced after SNI which could be confirmed by Western Blot analysis, quantitative RT-PCR and in-situ hybridisation. The decrease of latexin was associated with an increase of the activity of carboxypeptidase A indicating that the balance between latexin and carboxypeptidase A was impaired in the spinal cord after peripheral nerve injury due to a loss of latexin expression in spinal cord neurons. This may contribute to the development of cold allodynia because normalization of neuronal latexin expression in the spinal cord by AAV-mediated latexin transduction or administration of a small molecule carboxypeptidase A inhibitor significantly reduced acetone-evoked nociceptive behavior after SNI. Our results show the usefulness of proteomics as a screening tool to identify novel mechanisms of nerve injury evoked hypernociception and suggest that carboxypeptidase A inhibition might be useful to reduce cold allodynia.

  4. Nerve injury evoked loss of latexin expression in spinal cord neurons contributes to the development of neuropathic pain.

    Science.gov (United States)

    Kühlein, Hilmar Nils; Tegeder, Irmgard; Möser, Christine; Lim, Hee-Young; Häussler, Annett; Spieth, Katharina; Jennes, Ingo; Marschalek, Rolf; Beckhaus, Tobias; Karas, Michael; Fauth, Markus; Ehnert, Corina; Geisslinger, Gerd; Niederberger, Ellen

    2011-04-29

    Nerve injury leads to sensitization mechanisms in the peripheral and central nervous system which involve transcriptional and post-transcriptional modifications in sensory nerves. To assess protein regulations in the spinal cord after injury of the sciatic nerve in the Spared Nerve Injury model (SNI) we performed a proteomic analysis using 2D-difference gel electrophoresis (DIGE) technology. Among approximately 2300 protein spots separated on each gel we detected 55 significantly regulated proteins after SNI whereof 41 were successfully identified by MALDI-TOF MS. Out of the proteins which were regulated in the DIGE analyses after SNI we focused on the carboxypeptidase A inhibitor latexin because protease dysfunctions contribute to the development of neuropathic pain. Latexin protein expression was reduced after SNI which could be confirmed by Western Blot analysis, quantitative RT-PCR and in-situ hybridisation. The decrease of latexin was associated with an increase of the activity of carboxypeptidase A indicating that the balance between latexin and carboxypeptidase A was impaired in the spinal cord after peripheral nerve injury due to a loss of latexin expression in spinal cord neurons. This may contribute to the development of cold allodynia because normalization of neuronal latexin expression in the spinal cord by AAV-mediated latexin transduction or administration of a small molecule carboxypeptidase A inhibitor significantly reduced acetone-evoked nociceptive behavior after SNI. Our results show the usefulness of proteomics as a screening tool to identify novel mechanisms of nerve injury evoked hypernociception and suggest that carboxypeptidase A inhibition might be useful to reduce cold allodynia. © 2011 Kühlein et al.

  5. Transcriptional profiling of differentially vulnerable motor neurons at pre-symptomatic stage in the Smn (2b/-) mouse model of spinal muscular atrophy.

    Science.gov (United States)

    Murray, Lyndsay M; Beauvais, Ariane; Gibeault, Sabrina; Courtney, Natalie L; Kothary, Rashmi

    2015-09-15

    The term motor neuron disease encompasses a spectrum of disorders in which motor neurons are the lost. Importantly, while some motor neurons are lost early in disease and others remain intact at disease end-stage. This creates a valuable experimental paradigm to investigate the factors that regulate motor neuron vulnerability. Spinal muscular atrophy is a childhood motor neuron disease caused by mutations or deletions in the SMN1 gene. Here, we have performed transcriptional analysis on differentially vulnerable motor neurons from an intermediate mouse model of Spinal muscular atrophy at a presymptomatic time point. We have characterised two differentially vulnerable populations, differing in the level neuromuscular junction loss. Transcriptional analysis on motor neuron cell bodies revealed that reduced Smn levels correlate with a reduction of transcripts associated with the ribosome, rRNA binding, ubiquitination and oxidative phosphorylation. Furthermore, P53 pathway activation precedes neuromuscular junction loss, suggesting that denervation may be a consequence, rather than a cause of motor neuron death in Spinal muscular atrophy. Finally, increased vulnerability correlates with a decrease in the positive regulation of DNA repair. This study identifies pathways related to the function of Smn and associated with differential motor unit vulnerability, thus presenting a number of exciting targets for future therapeutic development.

  6. Weight-bearing locomotion in the developing opossum, Monodelphis domestica following spinal transection: remodeling of neuronal circuits caudal to lesion.

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    Benjamin J Wheaton

    Full Text Available Complete spinal transection in the mature nervous system is typically followed by minimal axonal repair, extensive motor paralysis and loss of sensory functions caudal to the injury. In contrast, the immature nervous system has greater capacity for repair, a phenomenon sometimes called the infant lesion effect. This study investigates spinal injuries early in development using the marsupial opossum Monodelphis domestica whose young are born very immature, allowing access to developmental stages only accessible in utero in eutherian mammals. Spinal cords of Monodelphis pups were completely transected in the lower thoracic region, T10, on postnatal-day (P7 or P28 and the animals grew to adulthood. In P7-injured animals regrown supraspinal and propriospinal axons through the injury site were demonstrated using retrograde axonal labelling. These animals recovered near-normal coordinated overground locomotion, but with altered gait characteristics including foot placement phase lags. In P28-injured animals no axonal regrowth through the injury site could be demonstrated yet they were able to perform weight-supporting hindlimb stepping overground and on the treadmill. When placed in an environment of reduced sensory feedback (swimming P7-injured animals swam using their hindlimbs, suggesting that the axons that grew across the lesion made functional connections; P28-injured animals swam using their forelimbs only, suggesting that their overground hindlimb movements were reflex-dependent and thus likely to be generated locally in the lumbar spinal cord. Modifications to propriospinal circuitry in P7- and P28-injured opossums were demonstrated by changes in the number of fluorescently labelled neurons detected in the lumbar cord following tracer studies and changes in the balance of excitatory, inhibitory and neuromodulatory neurotransmitter receptors' gene expression shown by qRT-PCR. These results are discussed in the context of studies indicating

  7. Generation patterns of four groups of cholinergic neurons in rat cervical spinal cord: a combined tritiated thymidine autoradiographic and choline acetyltransferase immunocytochemical study

    International Nuclear Information System (INIS)

    Phelps, P.E.; Barber, R.P.; Vaughn, J.E.

    1988-01-01

    This report examines the generation of cholinergic neurons in the spinal cord in order to determine whether the transmitter phenotype of neurons is associated with specific patterns of neurogenesis. Previous immunocytochemical studies identified four groups of choline acetyltransferase (ChAT)-positive neurons in the cervical enlargement of the rat spinal cord. These cell groups vary in both somatic size and location along the previously described ventrodorsal neurogenic gradient of the spinal cord. Thus, large (and small) motoneurons are located in the ventral horn, medium-sized partition cells are found in the intermediate gray matter, small central canal cluster cells are situated within lamina X, and small dorsal horn neurons are scattered predominantly through laminae III-V. The relationships among the birthdays of these four subsets of cholinergic neurons have been examined by combining 3H-thymidine autoradiography and ChAT immunocytochemistry. Embryonic day 11 was the earliest time that neurons were generated within the cervical enlargement. Large and small ChAT-positive motoneurons were produced on E11 and 12, with 70% of both groups being born on E11. ChAT-positive partition cells were produced between E11 and 13, with their peak generation occurring on E12. Approximately 70% of the cholinergic central canal cluster and dorsal horn cells were born on E13, and the remainder of each of these groups was generated on E14. Other investigators have shown that all neurons within the rat cervical spinal cord are produced in a ventrodorsal sequence between E11 and E16. In contrast, ChAT-positive neurons are born only from E11 to E14 and are among the earliest cells generated in the ventral, intermediate, and dorsal subdivisions of the spinal cord

  8. Targeting Neurotrophins to Specific Populations of Neurons: NGF, BDNF, and NT-3 and Their Relevance for Treatment of Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Kathleen M. Keefe

    2017-03-01

    Full Text Available Neurotrophins are a family of proteins that regulate neuronal survival, synaptic function, and neurotransmitter release, and elicit the plasticity and growth of axons within the adult central and peripheral nervous system. Since the 1950s, these factors have been extensively studied in traumatic injury models. Here we review several members of the classical family of neurotrophins, the receptors they bind to, and their contribution to axonal regeneration and sprouting of sensory and motor pathways after spinal cord injury (SCI. We focus on nerve growth factor (NGF, brain derived neurotrophic factor (BDNF, and neurotrophin-3 (NT-3, and their effects on populations of neurons within diverse spinal tracts. Understanding the cellular targets of neurotrophins and the responsiveness of specific neuronal populations will allow for the most efficient treatment strategies in the injured spinal cord.

  9. Targeting Neurotrophins to Specific Populations of Neurons: NGF, BDNF, and NT-3 and Their Relevance for Treatment of Spinal Cord Injury.

    Science.gov (United States)

    Keefe, Kathleen M; Sheikh, Imran S; Smith, George M

    2017-03-03

    Neurotrophins are a family of proteins that regulate neuronal survival, synaptic function, and neurotransmitter release, and elicit the plasticity and growth of axons within the adult central and peripheral nervous system. Since the 1950s, these factors have been extensively studied in traumatic injury models. Here we review several members of the classical family of neurotrophins, the receptors they bind to, and their contribution to axonal regeneration and sprouting of sensory and motor pathways after spinal cord injury (SCI). We focus on nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3), and their effects on populations of neurons within diverse spinal tracts. Understanding the cellular targets of neurotrophins and the responsiveness of specific neuronal populations will allow for the most efficient treatment strategies in the injured spinal cord.

  10. X-linked spinal muscular atrophy in mice caused by autonomous loss of ATP7A in the motor neuron.

    Science.gov (United States)

    Hodgkinson, Victoria L; Dale, Jeffery M; Garcia, Michael L; Weisman, Gary A; Lee, Jaekwon; Gitlin, Jonathan D; Petris, Michael J

    2015-06-01

    ATP7A is a copper-transporting P-type ATPase that is essential for cellular copper homeostasis. Loss-of-function mutations in the ATP7A gene result in Menkes disease, a fatal neurodegenerative disorder resulting in seizures, hypotonia and failure to thrive, due to systemic copper deficiency. Most recently, rare missense mutations in ATP7A that do not impact systemic copper homeostasis have been shown to cause X-linked spinal muscular atrophy type 3 (SMAX3), a distal hereditary motor neuropathy. An understanding of the mechanistic and pathophysiological basis of SMAX3 is currently lacking, in part because the disease-causing mutations have been shown to confer both loss- and gain-of-function properties to ATP7A, and because there is currently no animal model of the disease. In this study, the Atp7a gene was specifically deleted in the motor neurons of mice, resulting in a degenerative phenotype consistent with the clinical features in affected patients with SMAX3, including the progressive deterioration of gait, age-dependent muscle atrophy, denervation of neuromuscular junctions and a loss of motor neuron cell bodies. Taken together, these data reveal autonomous requirements for ATP7A that reveal essential roles for copper in the maintenance and function of the motor neuron, and suggest that SMAX3 is caused by a loss of ATP7A function that specifically impacts the spinal motor neuron. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  11. In vivo patch-clamp analysis of response properties of rat primary somatosensory cortical neurons responding to noxious stimulation of the facial skin

    Directory of Open Access Journals (Sweden)

    Nasu Masanori

    2010-05-01

    Full Text Available Abstract Background Although it has been widely accepted that the primary somatosensory (SI cortex plays an important role in pain perception, it still remains unclear how the nociceptive mechanisms of synaptic transmission occur at the single neuron level. The aim of the present study was to examine whether noxious stimulation applied to the orofacial area evokes the synaptic response of SI neurons in urethane-anesthetized rats using an in vivo patch-clamp technique. Results In vivo whole-cell current-clamp recordings were performed in rat SI neurons (layers III-IV. Twenty-seven out of 63 neurons were identified in the mechanical receptive field of the orofacial area (36 neurons showed no receptive field and they were classified as non-nociceptive (low-threshold mechanoreceptive; 6/27, 22% and nociceptive neurons. Nociceptive neurons were further divided into wide-dynamic range neurons (3/27, 11% and nociceptive-specific neurons (18/27, 67%. In the majority of these neurons, a proportion of the excitatory postsynaptic potentials (EPSPs reached the threshold, and then generated random discharges of action potentials. Noxious mechanical stimuli applied to the receptive field elicited a discharge of action potentials on the barrage of EPSPs. In the case of noxious chemical stimulation applied as mustard oil to the orofacial area, the membrane potential shifted depolarization and the rate of spontaneous discharges gradually increased as did the noxious pinch-evoked discharge rates, which were usually associated with potentiated EPSP amplitudes. Conclusions The present study provides evidence that SI neurons in deep layers III-V respond to the temporal summation of EPSPs due to noxious mechanical and chemical stimulation applied to the orofacial area and that these neurons may contribute to the processing of nociceptive information, including hyperalgesia.

  12. Inhibitory synaptic transmission in isolated patches of membrane from cultured rat spinal cord and medullary neurons.

    Science.gov (United States)

    Lewis, C A; Faber, D S

    1996-07-01

    1. To quantify the variability in the characteristics of inhibitory glycinergic and GABAergic currents at single synaptic connections between cultured rat embryonic spinal cord or medullary neurons, we have used patch-clamp techniques to record miniature inhibitory postsynaptic currents (mIPSCs) in cell-attached patches. Experiments were performed with the patch pipette containing either a low-calcium internal saline to allow comparison with subsequent whole cell recordings or external saline with tetrodotoxin, DL-2-amino-5-phosphonovaleric acid, and 6-cyano-7-nitroquinoxaline-2,3-dione, a solution that is more appropriate for bathing a nerve terminal. 2. The mIPSCs recorded from the synapses restricted to the cell-attached patches were characterized by their times to peak, amplitudes, and time constants of decay. The degree of variability in these characteristics was quantified with the use of the following model-independent parameters: the coefficient of variation, skewness, and kurtosis. The distribution of time to peak values has a mean value of 5.6 +/- 0.5 (SE) ms, has the lowest coefficient of variation (0.33 +/- 0.01), is fairly symmetrical, and has a Gaussian shape with respect to peakedness. On the other hand, both the amplitude and decay time constant distributions are highly skewed and more peaked than Gaussian distributions. The mean amplitude is -6.6 +/- 0.6 pA with a coefficient of variation of 0.60 +/- 0.05, whereas the mean decay time constant is 22.8 +/- 1.0 ms with a coefficient of variation of 0.81 +/- 0.03. 3. The amplitude distributions for spontaneous inhibitory currents recorded from cell-attached patches are best fitted by the sum of multiple Gaussians. The coefficient of variation for the first Gaussian peak fitted to the amplitude distributions is 0.290 +/- 0.028. 4. Decay time distributions were consistently best fitted by the sum of four Gaussians with decay constants as follows: D1 = 5.7 +/- 0.2 ms (n = 12), D2 = 11.2 +/- 0.7 ms (n = 11

  13. 5-HT2 and 5-HT7 receptor agonists facilitate plantar stepping in chronic spinal rats through actions on different populations of spinal neurons

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    Urszula eSlawinska

    2014-08-01

    Full Text Available There is considerable evidence from research in neonatal and adult rat and mouse preparations to warrant the conclusion that activation of 5-HT2 and 5-HT1A/7 receptors leads to activation of the spinal cord circuitry for locomotion. These receptors are involved in control of locomotor movements, but it is not clear how they are implicated in the responses to 5-HT agonists observed after spinal cord injury. Here we used agonists that are efficient in promoting locomotor recovery in paraplegic rats, 8-OHDPAT (acting on 5-HT1A/7 receptors and quipazine (acting on 5-HT2 receptors, to examine this issue. Analysis of intra- and interlimb coordination confirmed that the locomotor performance was significantly improved by either drug, but the data revealed marked differences in their mode of action. Interlimb coordination was significantly better after 8-OHDPAT application, and the activity of the extensor soleus muscle was significantly longer during the stance phase of locomotor movements enhanced by quipazine. Our results show that activation of both receptors facilitates locomotion, but their effects are likely exerted on different populations of spinal neurons. Activation of 5-HT2 receptors facilitates the output stage of the locomotor system, in part by directly activating motoneurons, and also through activation of interneurons of the locomotor CPG. Activation of 5-HT7/1A receptors facilitates the activity of the locomotor CPG, without direct actions on the output components of the locomotor system, including motoneurons. Although our findings show that the combined use of these two drugs results in production of well-coordinated weight supported locomotion with a reduced need for exteroceptive stimulation, they also indicate that there might be some limitations to the utility of combined treatment. Sensory feedback and some intraspinal circuitry recruited by the drugs can conflict with the locomotor activation.

  14. 5-HT₂ and 5-HT₇ receptor agonists facilitate plantar stepping in chronic spinal rats through actions on different populations of spinal neurons.

    Science.gov (United States)

    Sławińska, Urszula; Miazga, Krzysztof; Jordan, Larry M

    2014-01-01

    There is considerable evidence from research in neonatal and adult rat and mouse preparations to warrant the conclusion that activation of 5-HT2 and 5-HT1A/7 receptors leads to activation of the spinal cord circuitry for locomotion. These receptors are involved in control of locomotor movements, but it is not clear how they are implicated in the responses to 5-HT agonists observed after spinal cord injury. Here we used agonists that are efficient in promoting locomotor recovery in paraplegic rats, 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OHDPAT) (acting on 5-HT1A/7 receptors) and quipazine (acting on 5-HT2 receptors), to examine this issue. Analysis of intra- and interlimb coordination confirmed that the locomotor performance was significantly improved by either drug, but the data revealed marked differences in their mode of action. Interlimb coordination was significantly better after 8-OHDPAT application, and the activity of the extensor soleus muscle was significantly longer during the stance phase of locomotor movements enhanced by quipazine. Our results show that activation of both receptors facilitates locomotion, but their effects are likely exerted on different populations of spinal neurons. Activation of 5-HT2 receptors facilitates the output stage of the locomotor system, in part by directly activating motoneurons, and also through activation of interneurons of the locomotor central pattern generator (CPG). Activation of 5-HT7/1A receptors facilitates the activity of the locomotor CPG, without direct actions on the output components of the locomotor system, including motoneurons. Although our findings show that the combined use of these two drugs results in production of well-coordinated weight supported locomotion with a reduced need for exteroceptive stimulation, they also indicate that there might be some limitations to the utility of combined treatment. Sensory feedback and some intraspinal circuitry recruited by the drugs can conflict with the

  15. Early afferent activity from the facet joint after painful trauma to its capsule potentiates neuronal excitability and glutamate signaling in the spinal cord.

    Science.gov (United States)

    Crosby, Nathan D; Gilliland, Taylor M; Winkelstein, Beth A

    2014-09-01

    Cervical facet joint injury induces persistent pain and central sensitization. Preventing the peripheral neuronal signals that initiate sensitization attenuates neuropathic pain. Yet, there is no clear relationship among facet joint afferent activity, development of central sensitization, and pain, which may be hindering effective treatments for this pain syndrome. This study investigates how afferent activity from the injured cervical facet joint affects induction of behavioral sensitivity and central sensitization. Intra-articular bupivacaine was administered to transiently suppress afferent activity immediately or 4 days after facet injury. Mechanical hyperalgesia was monitored after injury, and spinal neuronal hyperexcitability and spinal expression of proteins that promote neuronal excitability were measured on day 7. Facet injury with saline vehicle treatment induced significant mechanical hyperalgesia (Pinjury significantly attenuated hyperalgesia (Pinjury. This study suggests that early afferent activity from the injured facet induces development of spinal sensitization via spinal excitatory glutamatergic signaling. Peripheral intervention blocking afferent activity is effective only over a short period of time early after injury and before spinal modifications develop, and is independent of modulating spinal glial activation. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  16. Firing characteristics of deep dorsal horn neurons after acute spinal transection during administration of agonists for 5-HT1B/1D and NMDA receptors

    Science.gov (United States)

    Thaweerattanasinp, Theeradej; Heckman, Charles J.

    2016-01-01

    Spinal cord injury (SCI) results in a loss of serotonin (5-HT) to the spinal cord and a loss of inhibition to deep dorsal horn (DDH) neurons, which produces an exaggerated excitatory drive to motoneurons. The mechanism of this excitatory drive could involve the DDH neurons triggering long excitatory postsynaptic potentials in motoneurons, which may ultimately drive muscle spasms. Modifying the activity of DDH neurons with drugs such as NMDA or the 5-HT1B/1D receptor agonist zolmitriptan could have a large effect on motoneuron activity and, therefore, on muscle spasms. In this study, we characterize the firing properties of DDH neurons after acute spinal transection in adult mice during administration of zolmitriptan and NMDA, using the in vitro sacral cord preparation and extracellular electrophysiology. DDH neurons can be categorized into three major types with distinct evoked and spontaneous firing characteristics: burst (bursting), simple (single spiking), and tonic (spontaneously tonic firing) neurons. The burst neurons likely contribute to muscle spasm mechanisms because of their bursting behavior. Only the burst neurons show significant changes in their firing characteristics during zolmitriptan and NMDA administration. Zolmitriptan suppresses the burst neurons by reducing their evoked spikes, burst duration, and spontaneous firing rate. Conversely, NMDA facilitates them by enhancing their burst duration and spontaneous firing rate. These results suggest that zolmitriptan may exert its antispastic effect on the burst neurons via activation of 5-HT1B/1D receptors, whereas activation of NMDA receptors may facilitate the burst neurons in contributing to muscle spasm mechanisms following SCI. PMID:27486104

  17. Firing characteristics of deep dorsal horn neurons after acute spinal transection during administration of agonists for 5-HT1B/1D and NMDA receptors.

    Science.gov (United States)

    Thaweerattanasinp, Theeradej; Heckman, Charles J; Tysseling, Vicki M

    2016-10-01

    Spinal cord injury (SCI) results in a loss of serotonin (5-HT) to the spinal cord and a loss of inhibition to deep dorsal horn (DDH) neurons, which produces an exaggerated excitatory drive to motoneurons. The mechanism of this excitatory drive could involve the DDH neurons triggering long excitatory postsynaptic potentials in motoneurons, which may ultimately drive muscle spasms. Modifying the activity of DDH neurons with drugs such as NMDA or the 5-HT 1B/1D receptor agonist zolmitriptan could have a large effect on motoneuron activity and, therefore, on muscle spasms. In this study, we characterize the firing properties of DDH neurons after acute spinal transection in adult mice during administration of zolmitriptan and NMDA, using the in vitro sacral cord preparation and extracellular electrophysiology. DDH neurons can be categorized into three major types with distinct evoked and spontaneous firing characteristics: burst (bursting), simple (single spiking), and tonic (spontaneously tonic firing) neurons. The burst neurons likely contribute to muscle spasm mechanisms because of their bursting behavior. Only the burst neurons show significant changes in their firing characteristics during zolmitriptan and NMDA administration. Zolmitriptan suppresses the burst neurons by reducing their evoked spikes, burst duration, and spontaneous firing rate. Conversely, NMDA facilitates them by enhancing their burst duration and spontaneous firing rate. These results suggest that zolmitriptan may exert its antispastic effect on the burst neurons via activation of 5-HT 1B/1D receptors, whereas activation of NMDA receptors may facilitate the burst neurons in contributing to muscle spasm mechanisms following SCI. Copyright © 2016 the American Physiological Society.

  18. Persistent at-level thermal hyperalgesia and tactile allodynia accompany chronic neuronal and astrocyte activation in superficial dorsal horn following mouse cervical contusion spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Jaime L Watson

    Full Text Available In humans, sensory abnormalities, including neuropathic pain, often result from traumatic spinal cord injury (SCI. SCI can induce cellular changes in the CNS, termed central sensitization, that alter excitability of spinal cord neurons, including those in the dorsal horn involved in pain transmission. Persistently elevated levels of neuronal activity, glial activation, and glutamatergic transmission are thought to contribute to the hyperexcitability of these dorsal horn neurons, which can lead to maladaptive circuitry, aberrant pain processing and, ultimately, chronic neuropathic pain. Here we present a mouse model of SCI-induced neuropathic pain that exhibits a persistent pain phenotype accompanied by chronic neuronal hyperexcitability and glial activation in the spinal cord dorsal horn. We generated a unilateral cervical contusion injury at the C5 or C6 level of the adult mouse spinal cord. Following injury, an increase in the number of neurons expressing ΔFosB (a marker of chronic neuronal activation, persistent astrocyte activation and proliferation (as measured by GFAP and Ki67 expression, and a decrease in the expression of the astrocyte glutamate transporter GLT1 are observed in the ipsilateral superficial dorsal horn of cervical spinal cord. These changes have previously been associated with neuronal hyperexcitability and may contribute to altered pain transmission and chronic neuropathic pain. In our model, they are accompanied by robust at-level hyperaglesia in the ipsilateral forepaw and allodynia in both forepaws that are evident within two weeks following injury and persist for at least six weeks. Furthermore, the pain phenotype occurs in the absence of alterations in forelimb grip strength, suggesting that it represents sensory and not motor abnormalities. Given the importance of transgenic mouse technology, this clinically-relevant model provides a resource that can be used to study the molecular mechanisms contributing to

  19. Persistent at-level thermal hyperalgesia and tactile allodynia accompany chronic neuronal and astrocyte activation in superficial dorsal horn following mouse cervical contusion spinal cord injury.

    Science.gov (United States)

    Watson, Jaime L; Hala, Tamara J; Putatunda, Rajarshi; Sannie, Daniel; Lepore, Angelo C

    2014-01-01

    In humans, sensory abnormalities, including neuropathic pain, often result from traumatic spinal cord injury (SCI). SCI can induce cellular changes in the CNS, termed central sensitization, that alter excitability of spinal cord neurons, including those in the dorsal horn involved in pain transmission. Persistently elevated levels of neuronal activity, glial activation, and glutamatergic transmission are thought to contribute to the hyperexcitability of these dorsal horn neurons, which can lead to maladaptive circuitry, aberrant pain processing and, ultimately, chronic neuropathic pain. Here we present a mouse model of SCI-induced neuropathic pain that exhibits a persistent pain phenotype accompanied by chronic neuronal hyperexcitability and glial activation in the spinal cord dorsal horn. We generated a unilateral cervical contusion injury at the C5 or C6 level of the adult mouse spinal cord. Following injury, an increase in the number of neurons expressing ΔFosB (a marker of chronic neuronal activation), persistent astrocyte activation and proliferation (as measured by GFAP and Ki67 expression), and a decrease in the expression of the astrocyte glutamate transporter GLT1 are observed in the ipsilateral superficial dorsal horn of cervical spinal cord. These changes have previously been associated with neuronal hyperexcitability and may contribute to altered pain transmission and chronic neuropathic pain. In our model, they are accompanied by robust at-level hyperaglesia in the ipsilateral forepaw and allodynia in both forepaws that are evident within two weeks following injury and persist for at least six weeks. Furthermore, the pain phenotype occurs in the absence of alterations in forelimb grip strength, suggesting that it represents sensory and not motor abnormalities. Given the importance of transgenic mouse technology, this clinically-relevant model provides a resource that can be used to study the molecular mechanisms contributing to neuropathic pain

  20. Effects of patterned peripheral nerve stimulation on soleus spinal motor neuron excitability

    DEFF Research Database (Denmark)

    Jimenez, Samuel; Mordillo-Mateos, Laura; Dileone, Michele

    2018-01-01

    Spinal plasticity is thought to contribute to sensorimotor recovery of limb function in several neurological disorders and can be experimentally induced in animals and humans using different stimulation protocols. In healthy individuals, electrical continuous Theta Burst Stimulation (TBS) of the ...

  1. Glial and neuronal connexin expression patterns in the rat spinal cord during development and following injury

    DEFF Research Database (Denmark)

    Lee, I. Hui; Lindqvist, Eva; Kiehn, Ole

    2005-01-01

    Spinal cord injury induces a complex cascade of degenerative and remodeling events evolving over time. The possible roles of changed intercellular communication via gap junctions after spinal cord injury (SCI) have remained relatively unexplored. We investigated the temporospatial expression...... was seen primarily in astrocytes and rarely in microglia. In contrast, Cx36 and Cx32 mRNA and proteins were relatively sparse and unchanged after spinal cord injury along the entire axis of the spinal cord. Cx43 is the most abundant gap junctional protein in the adult CNS and has been shown to form...... channels between astrocytes as well as between astrocytes and oligodendrocytes. Long-term up-regulation of Cx43 in reactive astrocytes may be one critical component in the rearrangement of the local astroglial network following SCI....

  2. Differential responses to ω-agatoxin IVA in murine frontal cortex and spinal cord derived neuronal networks.

    Science.gov (United States)

    Knaack, Gretchen L; Charkhkar, Hamid; Hamilton, Franz W; Peixoto, Nathalia; O'Shaughnessy, Thomas J; Pancrazio, Joseph J

    2013-07-01

    ω-Agatoxin-IVA is a well known P/Q-type Ca(2+) channel blocker and has been shown to affect presynaptic Ca(2+) currents as well postsynaptic potentials. P/Q-type voltage gated Ca(2+) channels play a vital role in presynaptic neurotransmitter release and thus play a role in action potential generation. Monitoring spontaneous activity of neuronal networks on microelectrode arrays (MEAs) provides an important tool for examining this neurotoxin. Changes in extracellular action potentials are readily observed and are dependent on synaptic function. Given the efficacy of murine frontal cortex and spinal cord networks to detect neuroactive substances, we investigated the effects of ω-agatoxin on spontaneous action potential firing within these networks. We found that networks derived from spinal cord are more sensitive to the toxin than those from frontal cortex; a concentration of only 10nM produced statistically significant effects on activity from spinal cord networks whereas 50 nM was required to alter activity in frontal cortex networks. Furthermore, the effects of the toxin on frontal cortex are more complex as unit specific responses were observed. These manifested as either a decrease or increase in action potential firing rate which could be statistically separated as unique clusters. Administration of bicuculline, a GABAA inhibitor, isolated a single response to ω-agatoxin, which was characterized by a reduction in network activity. These data support the notion that the two clusters detected with ω-agatoxin exposure represent differential responses from excitatory and inhibitory neuronal populations. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Spinal and supraspinal contributions to central sensitization in peripheral neuropathy.

    Science.gov (United States)

    Suzuki, Rie; Dickenson, Anthony

    2005-01-01

    We will focus on spinal cord dorsal horn lamina I projection neurones, their supraspinal targets and involvement in pain processing. These spinal cord neurons respond to tonic peripheral inputs by wind-up and other intrinsic mechanisms that cause central hyper-excitability, which in turn can further enhance afferent inputs. We describe here another hierarchy of excitation - as inputs arrive in lamina I, neurones rapidly inform the parabrachial area (PBA) and periaqueductal grey (PAG), areas associated with the affective and autonomic responses to pain. In addition, PBA can connect to areas of the brainstem that send descending projections down to the spinal cord - establishing a loop. The serotonin receptor, 5HT3, in the spinal cord mediates excitatory descending inputs from the brainstem. These descending excitatory inputs are needed for the full coding of polymodal peripheral inputs from spinal neurons and are enhanced after nerve injury. Furthermore, activity in this serotonergic system can determine the actions of gabapentin (GBP) that is widely used in the treatment of neuropathic pain. Thus, a hierarchy of separate, but interacting excitatory systems exist at peripheral, spinal and supraspinal sites that all converge on spinal neurones. The reciprocal relations between pain, fear, anxiety and autonomic responses are likely to be subserved by these spinal-brainstem-spinal pathways we describe here. Understanding these pain pathways is a first step toward elucidating the complex links between pain and emotions. Copyright 2005 S. Karger AG, Basel

  4. The role of c-AMP-dependent protein kinase in spinal cord and post synaptic dorsal column neurons in a rat model of visceral pain

    OpenAIRE

    Wu, Jing; Su, Guangxiao; Ma, Long; Zhang, Xuan; Lei, Yongzhong; Lin, Qing; Nauta, Haring J.W.; Li, Junfa; Fang, Li

    2007-01-01

    Visceral noxious stimulation induces central neuronal plasticity changes and suggests that the c-AMP-dependent protein kinase (PKA) signal transduction cascade contributes to long-term changes in nociceptive processing at the spinal cord level. Our previous studies reported the clinical neurosurgical interruption of post synaptic dorsal column neuron (PSDC) pathway by performing midline myelotomy effectively alleviating the intractable visceral pain in patients with severe pain. However, the ...

  5. Mastoparan-7 rescues botulinum toxin-A poisoned neurons in a mouse spinal cord cell culture model.

    Science.gov (United States)

    Zhang, Peng; Ray, Radharaman; Singh, Bal Ram; Ray, Prabhati

    2013-12-15

    Botulinum neurotoxin serotype A (BoNT/A) is the most potent poison of biological origin known to mankind. The toxicity of BoNT/A is due to the inhibition of neurotransmission at cholinergic synapses; this is responsible for the symptom of flaccid paralysis at peripheral neuromuscular junctions. At a molecular level, the BoNT/A effect is due to its inhibition of stimulated acetylcholine (ACh) release from presynaptic nerve terminals. Currently, there is no antidote available to rescue BoNT/A-poisoned synapses. Here, we report an example of rescuing botulinum-poisoned cultured mouse spinal cord neurons by treatment with Mastoparan-7 (Mas-7), which is known to be a phospholipase A2 activator compound. Mas-7, a naturally occurring bee venom peptide, was delivered to botulinum-poisoned neurons via a drug delivery vehicle (DDV) construct prepared using the recombinant non-toxic heavy chain (HC) fragment of BoNT/A itself. In this method, the BoNT/A HC component in the DDV served as a neuron specific drug targeting molecule. We found that Mas-7 delivered into BoNT/A intoxicated spinal cord cells restored over 40% their property of stimulated neurotransmitter release. Rescue from cell poisoning did not occur from inhibition of the endopeptidase activity of BoNT/A light chain (LC) against its well-known substrate, SNAP-25 that is mechanistically involved in the cholinergic neuroexocytosis process. Rather, Mas-7 induced a physiological host response apparently unrelated to SNAP-25, but linked to the phospholipase-mediated signal transduction pathway. Published by Elsevier Ltd.

  6. Antinociceptive action of oxytocin involves inhibition of potassium channel currents in lamina II neurons of the rat spinal cord

    Directory of Open Access Journals (Sweden)

    Darbon Pascal

    2009-11-01

    Full Text Available Abstract Background Growing evidence in the literature shows that oxytocin (OT has a strong spinal anti-nociceptive action. Oxytocinergic axons originating from a subpopulation of paraventricular hypothalamic neurons establish synaptic contacts with lamina II interneurons but little is known about the functional role of OT with respect to neuronal firing and excitability. Results Using the patch-clamp technique, we have recorded lamina II interneurons in acute transverse lumbar spinal cord slices of rats (15 to 30 days old and analyzed the OT effects on action potential firing ability. In the current clamp mode, we found that bath application of a selective OT-receptor agonist (TGOT reduced firing in the majority of lamina II interneurons exhibiting a bursting firing profile, but never in those exhibiting a single spike discharge upon depolarization. Interestingly, OT-induced reduction in spike frequency and increase of firing threshold were often observed, leading to a conversion of the firing profile from repetitive and delayed profiles into phasic ones and sometimes further into single spike profile. The observed effects following OT-receptor activation were completely abolished when the OT-receptor agonist was co-applied with a selective OT-receptor antagonist. In current and voltage clamp modes, we show that these changes in firing are strongly controlled by voltage-gated potassium currents. More precisely, transient IA currents and delayed-rectifier currents were reduced in amplitude and transient IA current was predominantly inactivated after OT bath application. Conclusion This effect of OT on the firing profile of lamina II neurons is in good agreement with the antinociceptive and analgesic properties of OT described in vivo.

  7. Reactive oxygen species enhance excitatory synaptic transmission in rat spinal dorsal horn neurons by activating TRPA1 and TRPV1 channels.

    Science.gov (United States)

    Nishio, N; Taniguchi, W; Sugimura, Y K; Takiguchi, N; Yamanaka, M; Kiyoyuki, Yasukuni; Yamada, H; Miyazaki, N; Yoshida, M; Nakatsuka, T

    2013-09-05

    Central neuropathic pain (CNP) in the spinal cord, such as chronic pain after spinal cord injury (SCI), is an incurable ailment. However, little is known about the spinal cord mechanisms underlying CNP. Recently, reactive oxygen species (ROS) have been recognized to play an important role in CNP of the spinal cord. However, it is unclear how ROS affect synaptic transmission in the dorsal horn of the spinal cord. To clarify how ROS impact on synaptic transmission, we investigated the effects of ROS on synaptic transmission in rat spinal cord substantia gelatinosa (SG) neurons using whole-cell patch-clamp recordings. Administration of tert-butyl hydroperoxide (t-BOOH), an ROS donor, into the spinal cord markedly increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) in SG neurons. This t-BOOH-induced enhancement was not suppressed by the Na(+) channel blocker tetrodotoxin. However, in the presence of a non-N-methyl-D-aspartate glutamate receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, t-BOOH did not generate any sEPSCs. Furthermore, in the presence of a transient receptor potential ankyrin 1 (TRPA1) channel antagonist (HC-030031) or a transient receptor potential vanilloid 1 (TRPV1) channel antagonist (capsazepine or AMG9810), the t-BOOH-induced increase in the frequency of sEPSCs was inhibited. These results indicate that ROS enhance the spontaneous release of glutamate from presynaptic terminals onto SG neurons through TRPA1 and TRPV1 channel activation. Excessive activation of these ion channels by ROS may induce central sensitization in the spinal cord and result in chronic pain such as that following SCI. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. The role of c-AMP-dependent protein kinase in spinal cord and post synaptic dorsal column neurons in a rat model of visceral pain.

    Science.gov (United States)

    Wu, Jing; Su, Guangxiao; Ma, Long; Zhang, Xuan; Lei, Yongzhong; Lin, Qing; Nauta, Haring J W; Li, Junfa; Fang, Li

    2007-04-01

    Visceral noxious stimulation induces central neuronal plasticity changes and suggests that the c-AMP-dependent protein kinase (PKA) signal transduction cascade contributes to long-term changes in nociceptive processing at the spinal cord level. Our previous studies reported the clinical neurosurgical interruption of post synaptic dorsal column neuron (PSDC) pathway by performing midline myelotomy effectively alleviating the intractable visceral pain in patients with severe pain. However, the intracellular cascade in PSDC neurons mediated by PKA nociceptive neurotransmission was not known. In this study, by using multiple experimental approaches, we investigated the role of PKA in nociceptive signaling in the spinal cord and PSDC neurons in a visceral pain model in rats with the intracolonic injection of mustard oil. We found that mustard oil injection elicited visceral pain that significantly changed exploratory behavior activity in rats in terms of decreased numbers of entries, traveled distance, active and rearing time, rearing activity and increased resting time when compared to that of rats receiving mineral oil injection. However, the intrathecal infusion of PKA inhibitor, H89 partially reversed the visceral pain-induced effects. Results from Western blot studies showed that mustard oil injection significantly induced the expression of PKA protein in the lumbosacral spinal cord. Immunofluorescent staining in pre-labeled PSDC neurons showed that mustard oil injection greatly induces the neuronal profile numbers. We also found that the intrathecal infusion of a PKA inhibitor, H89 significantly blocked the visceral pain-induced phosphorylation of c-AMP-responsive element binding (CREB) protein in spinal cord in rats. The results of our study suggest that the PKA signal transduction cascade may contribute to visceral nociceptive changes in spinal PSDC pathways.

  9. A Dual Functional Scaffold Tethered with EGFR Antibody Promotes Neural Stem Cell Retention and Neuronal Differentiation for Spinal Cord Injury Repair.

    Science.gov (United States)

    Xu, Bai; Zhao, Yannan; Xiao, Zhifeng; Wang, Bin; Liang, Hui; Li, Xing; Fang, Yongxiang; Han, Sufang; Li, Xiaoran; Fan, Caixia; Dai, Jianwu

    2017-05-01

    Neural stem cells (NSCs) transplantation is a promising strategy to restore neuronal relays and neurological function of injured spinal cord because of the differentiation potential into functional neurons, but the transplanted NSCs often largely diffuse from the transplanted site and mainly differentiate into glial cells rather than neurons due to the adverse microenviornment after spinal cord injury (SCI). This paper fabricates a dual functional collagen scaffold tethered with a collagen-binding epidermal growth factor receptor (EGFR) antibody to simultaneously promote NSCs retention and neuronal differentiation by specifically binding to EGFR molecule expressed on NSCs and attenuating EGFR signaling, which is responsible for the inhibition of differentiation of NSCs toward neurons. Compared to unmodified control scaffold, the dual functional scaffold promotes the adhesion and neuronal differentiation of NSCs in vitro. Moreover, the implantation of the dual functional scaffold with exogenous NSCs in rat SCI model can capture and retain NSCs at the injury sites, and promote the neuronal differentiation of the retained NSCs into functional neurons, and finally dedicate to improving motor function of SCI rats, which provides a potential strategy for synchronously promoting stem cell retention and differentiation with biomaterials for SCI repair. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Retrograde tracing of zinc-enriched (ZEN) neuronal somata in rat spinal cord

    DEFF Research Database (Denmark)

    Wang, Zhanyou; Danscher, G; Mook Jo, S

    2001-01-01

    SeAMG-labeled ZEN neurons appeared in Rexed's laminae V, VII and X while laminae I and II were void. A few scattered ZEN somata were observed in the remaining laminae. The labeled neurons differed in shape and size, and the relatively high level of labeled somata around the injection site suggests that many ZEN...

  11. Riluzole promotes motor and respiratory recovery associated with enhanced neuronal survival and function following high cervical spinal hemisection.

    Science.gov (United States)

    Satkunendrarajah, K; Nassiri, F; Karadimas, S K; Lip, A; Yao, G; Fehlings, M G

    2016-02-01

    Cervical spinal cord injury (SCI) can result in devastating functional deficits that involve the respiratory and hand function. The mammalian spinal cord has limited ability to regenerate and restore meaningful functional recovery following SCI. Riluzole, 2-amino-6-trifluoromethoxybenzothiazole, an anti-glutamatergic drug has been shown to reduce excitotoxicity and confer neuroprotection at the site of injury following experimental SCI. Based on promising preclinical studies, riluzole is currently under Phase III clinical trial for the treatment of SCI (ClinicalTrials.gov: NCT01597518). Riluzole's anti-glutamatergic role has the potential to regulate neuronal function and provide neuroprotection and influence glutamatergic connections distal to the initial injury leading to enhanced functional recovery following SCI. In order to investigate this novel role of riluzole we used a high cervical hemisection model of SCI, which interrupts all descending input to motoneurons innervating the ipsilateral forelimb and diaphragm muscles. Following C2 spinal cord hemisection, animals were placed into one of two groups: one group received riluzole (8 mg/kg) 1 h after injury and every 12 h thereafter for 7 days at 6 mg/kg, while the second group of injured rats received vehicle solution for the same duration of time. A third group of sham injured rats underwent a C2 laminectomy without hemisection and served as uninjured control rats. Interestingly, this study reports a significant loss of motoneurons within the cervical spinal cord caudal to C2 hemisection injury. Disruption of descending input led to a decrease in glutamatergic synapses and motoneurons caudal to the injury while riluzole treatment significantly limited this decline. Functionally, Hoffmann reflex recordings revealed an increase in the excitability of the remaining ipsilateral cervical motoneurons and significant improvements in skilled and unskilled forelimb function and respiratory motor function in the

  12. ESTROGEN RECEPTOR-alpha IMMUNOREACTIVE NEURONS IN THE BRAINSTEM AND SPINAL CORD OF THE FEMALE RHESUS MONKEY : SPECIES-SPECIFIC CHARACTERISTICS

    NARCIS (Netherlands)

    Vanderhorst, V. G. J. M.; Terasawa, E.; Ralston, H. J.

    2009-01-01

    The distribution pattern of estrogen receptors in the rodent CNS has been reported extensively, but mapping of estrogen receptors in primates is incomplete. In this study we describe the distribution of estrogen receptor alpha immunoreactive (ER-alpha 1R) neurons in the brainstem and spinal cord of

  13. Quantification, by solid-phase minisequencing, of the telomeric and centromeric copies of the survival motor neuron gene in families with spinal muscular atrophy

    DEFF Research Database (Denmark)

    Schwartz, M; Sørensen, N; Hansen, F J

    1997-01-01

    In an analysis of 30 families affected by spinal muscular atrophy (SMA) we have used the solid-phase minisequencing method to determine the ratio between the number of telomeric and centromeric copies of the survival motor neuron gene (SMN and cBCD541 respectively) on normal and SMA chromosomes...

  14. Targeting the Full Length of the Motor End Plate Regions in the Mouse Forelimb Increases the Uptake of Fluoro-Gold into Corresponding Spinal Cord Motor Neurons

    Directory of Open Access Journals (Sweden)

    Andrew Paul Tosolini

    2013-05-01

    Full Text Available Lower motor neuron dysfunction is one of the most debilitating motor conditions. In this regard, transgenic mouse models of various lower motor neuron dysfunctions provide insight into the mechanisms underlying these pathologies and can also aid the development of new therapies. Viral-mediated gene therapy can take advantage of the muscle-motor neuron topographical relationship to shuttle therapeutic genes into specific populations of motor neurons in these mouse models. In this context, motor end plates (MEPs are highly specialised regions on the skeletal musculature that offer direct access to the pre-synaptic nerve terminals, henceforth to the spinal cord motor neurons. The aim of this study was two-folded. First it was to characterise the exact position of the MEP regions for several muscles of the mouse forelimb using acetylcholinesterase histochemistry. This MEP-muscle map was then used to guide a series of intramuscular injections of Fluoro-Gold (FG in order to characterise the distribution of the innervating motor neurons. This analysis revealed that the MEPs are typically organised in an orthogonal fashion across the muscle fibres and extending throughout the full width of each muscle. Furthermore, targeting the full length of the MEP regions gave rise to a seemingly greater number of labelled motor neurons that are organised into columns spanning through more spinal cord segments than previously reported. The present analysis suggests that targeting the full width of the muscles’ MEP regions with FG increases the somatic availability of the tracer. This process ensures a greater uptake of the tracer by the pre-synaptic nerve terminals, hence maximising the labelling in spinal cord motor neurons. This investigation should have positive implications for future studies involving the somatic delivery of therapeutic genes into motor neurons for the treatment of various motor dysfunctions.

  15. The chemosensory basis for behavioral divergence involved in sympatric host shifts. I. Characterizing olfactory receptor neuron classes responding to key host volatiles.

    Science.gov (United States)

    Olsson, Shannon B; Linn, Charles E; Roelofs, Wendell L

    2006-03-01

    The recent shift of Rhagoletis pomonella from its native host hawthorn to introduced, domestic apple has been implicated as an example of sympatric speciation. Recent studies suggest that host volatile preference might play a fundamental role in host shifts and subsequent speciation in this group. Single sensillum electrophysiology was used to test a proposed hypothesis that differences in R. pomonella olfactory preference are due to changes in the number or odor specificity of olfactory receptor neurons. Individuals were analyzed from apple, hawthorn, and flowering dogwood-origin populations, as well as from the blueberry maggot, Rhagoletis mendax Curran (an outgroup). Eleven compounds were selected as biologically relevant stimuli from previous electroantennographic/behavioral studies of the three R. pomonella populations to host fruit volatiles. Cluster analysis of 99 neuron responses showed that cells from all tested populations could be grouped into the same five classes, ranging from those responding to one or two volatiles to those responding to several host volatiles. Topographical mapping also indicated that antennal neuron locations did not differ by class or fly taxa. Our results do not support the hypothesis that differences in host preference among Rhagoletis populations are a result of alterations in the number or class of receptor neurons responding to host volatiles.

  16. Dorsal root ganglion neurons innervating skeletal muscle respond to physiological combinations of protons, ATP, and lactate mediated by ASIC, P2X, and TRPV1.

    Science.gov (United States)

    Light, Alan R; Hughen, Ronald W; Zhang, Jie; Rainier, Jon; Liu, Zhuqing; Lee, Jeewoo

    2008-09-01

    The adequate stimuli and molecular receptors for muscle metaboreceptors and nociceptors are still under investigation. We used calcium imaging of cultured primary sensory dorsal root ganglion (DRG) neurons from C57Bl/6 mice to determine candidates for metabolites that could be the adequate stimuli and receptors that could detect these stimuli. Retrograde DiI labeling determined that some of these neurons innervated skeletal muscle. We found that combinations of protons, ATP, and lactate were much more effective than individually applied compounds for activating rapid calcium increases in muscle-innervating dorsal root ganglion neurons. Antagonists for P2X, ASIC, and TRPV1 receptors suggested that these three receptors act together to detect protons, ATP, and lactate when presented together in physiologically relevant concentrations. Two populations of muscle-innervating DRG neurons were found. One responded to low metabolite levels (likely nonnoxious) and used ASIC3, P2X5, and TRPV1 as molecular receptors to detect these metabolites. The other responded to high levels of metabolites (likely noxious) and used ASIC3, P2X4, and TRPV1 as their molecular receptors. We conclude that a combination of ASIC, P2X5 and/or P2X4, and TRPV1 are the molecular receptors used to detect metabolites by muscle-innervating sensory neurons. We further conclude that the adequate stimuli for muscle metaboreceptors and nociceptors are combinations of protons, ATP, and lactate.

  17. Substantial Early, But Nonprogressive Neuronal Loss in Multiple Sclerosis (MS) Spinal Cord

    NARCIS (Netherlands)

    Schirmer, Lucas; Albert, Monika; Buss, Armin; Schulz-Schaeffer, Walter J.; Antel, Jack P.; Brueck, Wolfgang; Stadelmann, Christine

    2009-01-01

    Research in multiple sclerosis (MS) has recently been focusing on the extent of neuroaxonal damage and its contribution to disease outcome. In the present Study, we examined spinal cord tissue from 30 clinically well-characterized MS patients. MS, amyotrophic lateral sclerosis (ALS), and control

  18. Involvement of ERK phosphorylation of trigeminal spinal subnucleus caudalis neurons in thermal hypersensitivity in rats with infraorbital nerve injury.

    Science.gov (United States)

    Suzuki, Ikuko; Tsuboi, Yoshiyuki; Shinoda, Masamichi; Shibuta, Kazuo; Honda, Kuniya; Katagiri, Ayano; Kiyomoto, Masaaki; Sessle, Barry J; Matsuura, Shingo; Ohara, Kinuyo; Urata, Kentaro; Iwata, Koichi

    2013-01-01

    To evaluate the involvement of the mitogen-activated protein kinase (MAPK) cascade in orofacial neuropathic pain mechanisms, this study assessed nocifensive behavior evoked by mechanical or thermal stimulation of the whisker pad skin, phosphorylation of extracellular signal-regulated kinase (ERK) in trigeminal spinal subnucleus caudalis (Vc) neurons, and Vc neuronal responses to mechanical or thermal stimulation of the whisker pad skin in rats with the chronic constriction nerve injury of the infraorbital nerve (ION-CCI). The mechanical and thermal nocifensive behavior was significantly enhanced on the side ipsilateral to the ION-CCI compared to the contralateral whisker pad or sham rats. ION-CCI rats had an increased number of phosphorylated ERK immunoreactive (pERK-IR) cells which also manifested NeuN-IR but not GFAP-IR and Iba1-IR, and were significantly more in ION-CCI rats compared with sham rats following noxious but not non-noxious mechanical stimulation. After intrathecal administration of the MEK1 inhibitor PD98059 in ION-CCI rats, the number of pERK-IR cells after noxious stimulation and the enhanced thermal nocifensive behavior but not the mechanical nocifensive behavior were significantly reduced in ION-CCI rats. The enhanced background activities, afterdischarges and responses of wide dynamic range neurons to noxious mechanical and thermal stimulation in ION-CCI rats were significantly depressed following i.t. administration of PD98059, whereas responses to non-noxious mechanical and thermal stimulation were not altered. The present findings suggest that pERK-IR neurons in the Vc play a pivotal role in the development of thermal hypersensitivity in the face following trigeminal nerve injury.

  19. Morphological Characteristics of Motor Neurons Do Not Determine Their Relative Susceptibility to Degeneration in a Mouse Model of Severe Spinal Muscular Atrophy

    Science.gov (United States)

    Mutsaers, Chantal A.; Thomson, Derek; Hamilton, Gillian; Parson, Simon H.; Gillingwater, Thomas H.

    2012-01-01

    Spinal muscular atrophy (SMA) is a leading genetic cause of infant mortality, resulting primarily from the degeneration and loss of lower motor neurons. Studies using mouse models of SMA have revealed widespread heterogeneity in the susceptibility of individual motor neurons to neurodegeneration, but the underlying reasons remain unclear. Data from related motor neuron diseases, such as amyotrophic lateral sclerosis (ALS), suggest that morphological properties of motor neurons may regulate susceptibility: in ALS larger motor units innervating fast-twitch muscles degenerate first. We therefore set out to determine whether intrinsic morphological characteristics of motor neurons influenced their relative vulnerability to SMA. Motor neuron vulnerability was mapped across 10 muscle groups in SMA mice. Neither the position of the muscle in the body, nor the fibre type of the muscle innervated, influenced susceptibility. Morphological properties of vulnerable and disease-resistant motor neurons were then determined from single motor units reconstructed in Thy.1-YFP-H mice. None of the parameters we investigated in healthy young adult mice – including motor unit size, motor unit arbor length, branching patterns, motor endplate size, developmental pruning and numbers of terminal Schwann cells at neuromuscular junctions - correlated with vulnerability. We conclude that morphological characteristics of motor neurons are not a major determinant of disease-susceptibility in SMA, in stark contrast to related forms of motor neuron disease such as ALS. This suggests that subtle molecular differences between motor neurons, or extrinsic factors arising from other cell types, are more likely to determine relative susceptibility in SMA. PMID:23285108

  20. Survival of motor neuron protein downregulates miR-9 expression in patients with spinal muscular atrophy

    Directory of Open Access Journals (Sweden)

    Li-Ting Wang

    2014-05-01

    Full Text Available Spinal muscular atrophy (SMA is a lethal hereditary disease caused by homozygous absence of the survival of the motor neuron (SMN 1 gene (SMN1, and it is the leading genetic cause of infant mortality. The severity of SMA is directly correlated with SMN protein levels in affected patients; however, the cellular regulatory mechanisms for SMN protein expression are not completely understood. In this study, we investigated the regulatory effects between SMN expression and miR-9a, a downstream noncoding small RNA. Using an inducible SMN short hairpin RNA interference (shRNAi system in NSC 34 and human skin fibroblast cells, cellular miR-9 levels and SMN protein repression were time-dependently upregulated. Conversely, cellular miR-9 levels decreased when HeLa cells were transfected with SMN protein fused with green fluorescent protein. In SMA-like mice spinal cords and human primary skin fibroblasts isolated from patients with different degrees of SMA, human SMN exhibited a disease severity-dependent decrease, whereas cellular miR-9 levels increased. These results clearly suggested that cellular SMN proteins regulated miR-9 expression and that miR-9 expression was related to SMA severity. Thus, miR-9 may be a marker for SMA prognosis.

  1. Spinal motor neuron neuroaxonal spheroids in chronic aluminum neurotoxicity contain phosphatase-resistant high molecular weight neurofilament (NFH).

    Science.gov (United States)

    Gaytan-Garcia, S; Kim, H; Strong, M J

    1996-04-15

    It has previously been shown that a single intracisternal inoculum of AlCl3 in young adult New Zealand white rabbits will induce a dose-dependent phosphatase resistance of high molecular weight neurofilament protein (NFH) that is proportionate to the extent of neurofilamentous inclusion formation (Strong and Jakowec, 1994). To determine if the potential for dissolution of aluminum-induced neurofilamentous inclusions was dependent on the degree of NFH phosphatase resistance, we have examined NFH phosphatase sensitivity in a reversible chronic model of aluminum neurotoxicity. Rabbits receiving repeated intracisternal inoculums of 100 microgram AlCl3 at 28 day intervals until day 267 develop spinal motor neuron perikaryal and neuroaxonal neurofilamentous aggregates in a stereotypic, dose-dependent fashion. In the rabbits receiving inoculums until day 156 with survival until day 267 without further aluminum exposure, neuroaxonal spheroids remained prominent while perikaryal inclusions largely resolved. Immunoreactivity to a monoclonal antibody recognizing phosphorylated NFH (SMI 31) was abolished in perikaryal aggregates at each time interval by dephosphorylation with bovine alkaline phosphatase. However, neuroaxonal spheroids maintained their immunoreactivity. Using time-course dephosphorylation studies of spinal cord homogenates, we observed a significant reduction in the rate of dephosphorylation of NFH following 267 days of AlCl3 exposure (P < 0.05). These observations suggest that neuroaxonal spheroids contain phosphatase-resistant NFH isoforms and that the potential for resolution of intraneuronal neurofilamentous inclusions correlates with the susceptibility of NF within these inclusions to enzymatic dephosphorylation.

  2. The effects of spinal cord stimulation on the neuronal activity of the brain in patients with chronic neuropathic pain

    International Nuclear Information System (INIS)

    Kunitake, Ayumi; Hidaka, Nami; Katsuki, Hiroshi; Iwasaki, Tatsuma; Nagamachi, Shigeki; Takasaki, Mayumi; Uno, Takeshi

    2005-01-01

    The effects of spinal cord stimulation (SCS) on the neuronal activity of the brain were examined by single photon emission computed tomography (SPECT) in patients with chronic neuropathic pain. Regional cerebral blood flow (CBF) in each cortical area and the thalamus decreased in several patients without SCS. Patients with central pain due to thalamic hemorrhage showed a decrease in rCBF in the thalamus contralateral to the painful side. During the stimulation period in SCS, parietal rCBF decreased on the side contralateral to the pain. In contrast, rCBF increased in the bilateral frontal and anterior cingulate cortex and in the contralateral temporal lobe in half of the patients in whom SCS was effective in relieving pain. The decrease in thalamic rCBF in two patients with central pain was improved by the SCS therapy; however, pain was relieved in only one of them. In the majority of patients in whom SCS was not effective, there was no change in rCBF in various cortical areas, even after SCS. These results suggest that, in patients with chronic neuropathic pain, SCS modulates the neuronal activities of several brain areas that are believed to be associated with pain processing. (author)

  3. Muscle expression of mutant androgen receptor accounts for systemic and motor neuron disease phenotypes in spinal and bulbar muscular atrophy.

    Science.gov (United States)

    Cortes, Constanza J; Ling, Shuo-Chien; Guo, Ling T; Hung, Gene; Tsunemi, Taiji; Ly, Linda; Tokunaga, Seiya; Lopez, Edith; Sopher, Bryce L; Bennett, C Frank; Shelton, G Diane; Cleveland, Don W; La Spada, Albert R

    2014-04-16

    X-linked spinal and bulbar muscular atrophy (SBMA) is characterized by adult-onset muscle weakness and lower motor neuron degeneration. SBMA is caused by CAG-polyglutamine (polyQ) repeat expansions in the androgen receptor (AR) gene. Pathological findings include motor neuron loss, with polyQ-AR accumulation in intranuclear inclusions. SBMA patients exhibit myopathic features, suggesting a role for muscle in disease pathogenesis. To determine the contribution of muscle, we developed a BAC mouse model featuring a floxed first exon to permit cell-type-specific excision of human AR121Q. BAC fxAR121 mice develop systemic and neuromuscular phenotypes, including shortened survival. After validating termination of AR121 expression and full rescue with ubiquitous Cre, we crossed BAC fxAR121 mice with Human Skeletal Actin-Cre mice. Muscle-specific excision prevented weight loss, motor phenotypes, muscle pathology, and motor neuronopathy and dramatically extended survival. Our results reveal a crucial role for muscle expression of polyQ-AR in SBMA and suggest muscle-directed therapies as effective treatments. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Morphological changes in different populations of bladder afferent neurons detected by herpes simplex virus (HSV) vectors with cell-type-specific promoters in mice with spinal cord injury.

    Science.gov (United States)

    Shimizu, Nobutaka; Doyal, Mark F; Goins, William F; Kadekawa, Katsumi; Wada, Naoki; Kanai, Anthony J; de Groat, William C; Hirayama, Akihide; Uemura, Hirotsugu; Glorioso, Joseph C; Yoshimura, Naoki

    2017-11-19

    Functional and morphological changes in C-fiber bladder afferent pathways are reportedly involved in neurogenic detrusor overactivity (NDO) after spinal cord injury (SCI). This study examined the morphological changes in different populations of bladder afferent neurons after SCI using replication-defective herpes simplex virus (HSV) vectors encoding the mCherry reporter driven by neuronal cell-type-specific promoters. Spinal intact (SI) and SCI mice were injected into the bladder wall with HSV mCherry vectors driven by the cytomegalovirus (CMV) promoter, CGRP promoter, TRPV1 promoter or neurofilament 200 (NF200) promoter. Two weeks after vector inoculation into the bladder wall, L1 and L6 dorsal root ganglia (DRG) were removed bilaterally for immunofluorescent staining using anti-mCherry antibody. The number of CMV promoter vector-labeled neurons was not altered after SCI. The number of CGRP and TRPV1 promoter vector-labeled neurons was significantly increased whereas the number of NF200 vector-labeled neurons was decreased in L6 DRG after SCI. The median size of CGRP promoter-labeled C-fiber neurons was increased from 247.0 in SI mice to 271.3μm 2 in SCI mice whereas the median cell size of TRPV1 promoter vector-labeled neurons was decreased from 245.2 in SI mice to 216.5μm 2 in SCI mice. CGRP and TRPV1 mRNA levels of laser-captured bladder afferent neurons labeled with Fast Blue were significantly increased in SCI mice compared to SI mice. Thus, using a novel HSV vector-mediated neuronal labeling technique, we found that SCI induces expansion of the CGRP- and TRPV1-expressing C-fiber cell population, which could contribute to C-fiber afferent hyperexcitability and NDO after SCI. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. Sciatic nerve ligation causes impairment of mitochondria associated with changes in distribution, respiration, and cardiolipin composition in related spinal cord neurons in rats.

    Science.gov (United States)

    Keilhoff, Gerburg; Becker, Axel; Kropf, Siegfried; Schild, Lorenz

    2016-10-01

    Sciatic nerve irritation is often associated with disturbed Ca(2+) homeostasis in related neurons of the spinal cord. Since mitochondria substantially contribute to Ca(2+) homeostasis and little information is available, we studied the effects of loose sciatic nerve ligation, a chronic constriction injury (CCI), on neuronal mitochondria of the L3-L6 regions. Three groups of rats (untreated, sham operated, and ligated) were explored. For the characterization of mitochondria, specimens of the L3-L6 spinal cord regions were evaluated with respect to intracellular localization using pyruvate dehydrogenase immunohistochemistry and Mitotracker Red, and the ATP producing machinery by LC-MS/MS technique for the analysis of cardiolipin and high-resolution respirometry for the measurement of oxygen consumption. Therefore, the phospholipid cardiolipin supports electron transfer within the respiratory chain as part of mitochondrial respiration and is of high impact on the physical properties of the mitochondrial membrane system. Histological analysis of spinal cord motor neurons revealed clustering of mitochondria in ipsilateral samples from ligated animals 14 days after the insult. This phenomenon was similarly evident in the respective contralateral side. The intensity of MT-Red staining was enhanced exclusively at the ipsilateral side, indicating increased mitochondrial activity. CCI of the sciatic nerve caused massive changes in the composition of cardiolipin reflecting mitochondrial impairment in the early phase followed by regeneration processes as late response. Sciatic nerve CCI caused decrease in the capacity of mitochondrial ATP production that recovered within 14 days after treatment. In conclusion, we provide evidence that clustering of mitochondria, already verified for the spinal cord sensory neurons after CCI, also occurs in the respective motor neurons. Further we have demonstrated transient impairment of the capacity of mitochondrial ATP production in tissue

  6. Differentiation of human bone marrow precursor cells into neuronal-like cells after transplantation into canine spinal cord organotypic slice cultures.

    Science.gov (United States)

    Fei, Zhi-qiang; Xiong, Jian-yi; Chen, Lei; Shen, Hui-yong; Stephanie, Ngo; Jeffrey, Wang; Wang, Da-ping

    2012-11-01

    Treatments to regenerate different tissue involving the transplantation of bone marrow derived mesenchymal precursor cells are anticipated. Using an alternative methods, in vitro organotypic slice culture method, would be useful to transplant cells and assessing the effects. This study was to determine the possibility of differentiating human bone marrow precursor cells into cells of the neuronal lineage by transplanting into canine spinal cord organotypic slice cultures. Bone marrow aspirates were obtained from posterior superior iliac spine (PSIS) of patients that had undergone spinal fusion due to a degenerative spinal disorder. For cell imaging, mesenchymal precursor cells (MPCs) were pre-stained with PKH-26 just before transplantation to canine spinal cord slices. Canine spinal cord tissues were obtained from three adult beagle dogs. Spinal cords were cut into transverse slices of 1 mm using tissue chopper. Two slices were transferred into 6-well plate containing 3 ml DMEM with antibiotics. Prepared MPCs (1×10(4)) were transplanted into spinal cord slices. On days 0, 3, 7, 14, MPCs were observed for morphological changes and expression of neuronal markers through immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). The morphological study showed: spherical cells in the control and experiment groups on day 0; and on day 3, cells in the control group had one or two thick, short processes and ones in the experiment group had three or four thin, long processes. On day 7, these variously-sized processes contacted each other in the experiment group, but showed typical spindle-shaped cells in the control group. Immunofluorescence showed that PKH-26(+) MPCs stained positive for NeuN(+) and GFAP(+) in experimental group only. Also RT-PCR showed weak expression of β-tubulin III and GFAP. Human bone marrow mesenchymal precursor cells (hMPCs) have the potential to differentiate into the neuronal like cells in this canine spinal cord

  7. Spinal motor neuron involvement in a patient with homozygous PRUNE mutation.

    Science.gov (United States)

    Iacomino, Michele; Fiorillo, Chiara; Torella, Annalaura; Severino, Mariasavina; Broda, Paolo; Romano, Catia; Falsaperla, Raffaele; Pozzolini, Giulia; Minetti, Carlo; Striano, Pasquale; Nigro, Vincenzo; Zara, Federico

    2018-05-01

    In the last few years, whole exome sequencing (WES) allowed the identification of PRUNE mutations in patients featuring a complex neurological phenotype characterized by severe neurodevelopmental delay, microcephaly, epilepsy, optic atrophy, and brain or cerebellar atrophy. We describe an additional patient with homozygous PRUNE mutation who presented with spinal muscular atrophy phenotype, in addition to the already known brain developmental disorder. This novel feature expands the clinical consequences of PRUNE mutations and allow to converge PRUNE syndrome with previous descriptions of neurodevelopmental/neurodegenerative disorders linked to altered microtubule dynamics. Copyright © 2017 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  8. Frontal Connectivity in EEG Gamma (30-45 Hz) Respond to Spinal Cord Stimulation in Minimally Conscious State Patients.

    Science.gov (United States)

    Bai, Yang; Xia, Xiaoyu; Liang, Zhenhu; Wang, Yong; Yang, Yi; He, Jianghong; Li, Xiaoli

    2017-01-01

    Spinal cord stimulation (SCS) has become a valuable brain-intervention technique used to rehabilitate patients with disorders of consciousness (DOC). To explore how the SCS affects the cerebral cortex and what possible electrophysiological mechanism of SCS effects on the cortex, the present study investigated the functional connectivity and network properties during SCS in minimally conscious state (MCS) patients. MCS patients received both SCS and sham sessions. Functional connectivity of the phase lock value (PLV) in the gamma band (30-45 Hz) was investigated at the pre-, on- and post-SCS stages. In addition, to evaluate global network properties, complex network parameters, including average path length, cluster coefficient and small-world, were measured. When SCS was turned on, significantly decreased connectivity was noted in the local scale of the frontal-frontal region and in the large scales of the frontal-parietal and frontal-occipital regions. The global network showed fewer small-world properties, average path lengths increased and cluster coefficients decreased. When SCS was turned off, the large-scale connectivity and global network returned to its pre-SCS level, but the local scale of frontal-frontal connectivity remained significantly lower than its pre-SCS level. Sham sessions produced no significant changes in either functional connectivity or network. The findings directly showed that SCS could effectively intervene cortical gamma activity, and the intervention included immediate global effects (large scale connectivity and network alteration only occurred in stimulation period) and long-lasting local effects (local scale connectivity alteration persist beyond stimulation period). Moreover, considering the mechanism and propagation of gamma activity, it indicates that the frontal cortex plays a crucial role in the SCS effects on the cerebral cortex.

  9. Co-expression of GAD67 and choline acetyltransferase in neurons in the mouse spinal cord: A focus on lamina X.

    Science.gov (United States)

    Gotts, Jittima; Atkinson, Lucy; Yanagawa, Yuchio; Deuchars, Jim; Deuchars, Susan A

    2016-09-01

    Lamina X of the spinal cord is a functionally diverse area with roles in locomotion, autonomic control and processing of mechano and nociceptive information. It is also a neurochemically diverse region. However, the different populations of cells in lamina X remain to be fully characterised. To determine the co-localisation of the enzymes responsible for the production of GABA and acetylcholine (which play major roles in the spinal cord) in lamina X of the adult and juvenile mouse, we used a transgenic mouse expressing green fluorescent protein (GFP) in glutamate decarboxylase 67 (GAD67) neurons, combined with choline acetyltransferase (ChAT) immunohistochemistry. ChAT-immunoreactive (IR) and GAD67-GFP containing neurons were observed in lamina X of both adult and juvenile mice and in both age groups a population of cells containing both ChAT-IR and GAD67-GFP were observed in lumbar, thoracic and cervical spinal cord. Such dual labelled cells were predominantly located ventral to the central canal. Immunohistochemistry for vesicular acetylcholine transporter (VAChT) and GAD67 revealed a small number of double labelled terminals located lateral, dorsolateral and ventrolateral to the central canal. This study therefore describes in detail a population of ChAT-IR/GAD67-GFP neurons predominantly ventral to the central canal of the cervical, thoracic and lumbar spinal cord of adult and juvenile mice. These cells potentially correspond to a sub-population of the cholinergic central canal cluster cells which may play a unique role in controlling spinal cord circuitry. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Blockade of 5-HT2A receptors at the site of inflammation inhibits activation of spinal dorsal horn neurons in rats.

    Science.gov (United States)

    Hu, Wei; Zhang, Yan; Cai, Qiaoyan; Wang, Dongmei; Hong, Yanguo

    2016-06-01

    Repeated inflammation in the periphery is a major cause of chronic inflammatory pain. We have showed that blockade of 5-HT2A receptors in the periphery inhibits repeated inflammation-induced pain hypersensitivity. The present study investigated whether inhibition of 5-HT2A receptor signaling at the site of inflammation could inhibit repeated inflammation-induced neurochemical changes in spinal dorsal horn neurons. Treatment with the 5-HT2A receptor antagonist ketanserin (20μg) in the hindpaw following intraplantar injection of carrageenan inhibited the increase in nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) reactivity, a marker of nitric oxide synthase (NOS), in the spinal dorsal horn. Administration of formalin (1%) in the hindpaw following the carrageenan injection evoked a great increase in NADPH-d reactivity in spinal dorsal horn neurons on the ipsilateral and contralateral sides. These changes were abolished by the pretreatment of ketanserin (20μg). The ketanserin treatment also reduced the repeated inflammation-induced expression of protein kinase gamma (PKCγ) in the membrane of spinal dorsal horn neurons and increased PKCγ protein level in the cytosol. Following the treatment with the opioid receptor antagonist naloxone methiodide (5mg/kg, s.c.), the administration of ketanserin failed to inhibit the repeated inflammation-induced increase in NADPH-d reactivity and c-Fos expression in the spinal dorsal horn. These results suggest that 5-HT2A receptor bioactivity in the inflammatory site plays an important role in repeated inflammation-induced central sensitization. The present study supports the notion that targeting 5-HT2A receptors in the periphery can be a promising therapy for relieving chronic inflammatory pain. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Salmon and human thrombin differentially regulate radicular pain, glial-induced inflammation and spinal neuronal excitability through protease-activated receptor-1.

    Directory of Open Access Journals (Sweden)

    Jenell R Smith

    Full Text Available Chronic neck pain is a major problem with common causes including disc herniation and spondylosis that compress the spinal nerve roots. Cervical nerve root compression in the rat produces sustained behavioral hypersensitivity, due in part to the early upregulation of pro-inflammatory cytokines, the sustained hyperexcitability of neurons in the spinal cord and degeneration in the injured nerve root. Through its activation of the protease-activated receptor-1 (PAR1, mammalian thrombin can enhance pain and inflammation; yet at lower concentrations it is also capable of transiently attenuating pain which suggests that PAR1 activation rate may affect pain maintenance. Interestingly, salmon-derived fibrin, which contains salmon thrombin, attenuates nerve root-induced pain and inflammation, but the mechanisms of action leading to its analgesia are unknown. This study evaluates the effects of salmon thrombin on nerve root-mediated pain, axonal degeneration in the root, spinal neuronal hyperexcitability and inflammation compared to its human counterpart in the context of their enzymatic capabilities towards coagulation substrates and PAR1. Salmon thrombin significantly reduces behavioral sensitivity, preserves neuronal myelination, reduces macrophage infiltration in the injured nerve root and significantly decreases spinal neuronal hyperexcitability after painful root compression in the rat; whereas human thrombin has no effect. Unlike salmon thrombin, human thrombin upregulates the transcription of IL-1β and TNF-α and the secretion of IL-6 by cortical cultures. Salmon and human thrombins cleave human fibrinogen-derived peptides and form clots with fibrinogen with similar enzymatic activities, but salmon thrombin retains a higher enzymatic activity towards coagulation substrates in the presence of antithrombin III and hirudin compared to human thrombin. Conversely, salmon thrombin activates a PAR1-derived peptide more weakly than human thrombin. These

  12. Effect of a calcitonin gene-related peptide-binding L-RNA aptamer on neuronal activity in the rat spinal trigeminal nucleus

    OpenAIRE

    Fischer, Michael J. M.; Schmidt, Jakob; Koulchitsky, Stanislav; Klussmann, Sven; Vater, Axel; Messlinger, Karl

    2018-01-01

    Background Calcitonin gene-related peptide (CGRP) plays a major role in the pathogenesis of migraine and other primary headaches. Spinal trigeminal neurons integrate nociceptive afferent input from trigeminal tissues including intracranial afferents, and their activity is thought to reflect facial pain and headache in man. CGRP receptor inhibitors and anti-CGRP antibodies have been demonstrated to be therapeutically effective in migraine. In parallel, CGRP receptor inhibition has been shown t...

  13. Endogenous neural stem cells in central canal of adult rats acquired limited ability to differentiate into neurons following mild spinal cord injury

    Science.gov (United States)

    Liu, Yuan; Tan, Botao; Wang, Li; Long, Zaiyun; Li, Yingyu; Liao, Weihong; Wu, Yamin

    2015-01-01

    Endogenous neural stem cells in central canal of adult mammalian spinal cord exhibit stem cell properties following injury. In the present study, the endogenous neural stem cells were labeled with Dil to track the differentiation of cells after mild spinal cord injury (SCI). Compared with 1 and 14 days post mild injury, the number of endogenous neural stem cells significantly increased at the injured site of spinal cord on 3 and 7 days post-injury. Dil-labeled βIII-tublin and GFAP expressing cells could be detected on 7 days post-injury, which indicated that the endogenous neural stem cells in central canal of spinal cord differentiated into different type of neural cells, but there were more differentiated astrocytes than the neurons after injury. Furthermore, after injury the expression of inhibitory Notch1 and Hes1 mRNA began to increase at 6 hours and was evident at 12 and 24 hours, which maintained high levels up to 7 days post-injury. These results indicated that a mild SCI in rat is sufficient to induce endogenous neural stem cells proliferation and differentiation. However, the ability to differentiate into neurons is limited, which may be, at least in part, due to high expression of inhibitory Notch1 and Hes1 genes after injury. PMID:26097566

  14. The effect of Bobath approach on the excitability of the spinal alpha motor neurones in stroke patients with muscle spasticity.

    Science.gov (United States)

    Ansari, N N; Naghdi, S

    2007-01-01

    A clinical study was performed to evaluate the efficacy of the Bobath approach on the excitability of the spinal alpha motor neurones in patients with poststroke spasticity. Ten subjects ranging in age from 37 through 76 years (average 60 years) with ankle plantarflexor spasticity secondary to a stroke were recruited and completed the trial. They had physiotherapy according to Bobath concept for ten treatment sessions, three days per week. Two repeated measures, one before and another after treatment, were taken to quantify clinical efficacy. The effect of this type of therapy on the excitability of alpha motor neurones (aMN) was assessed by measuring the latency of the Hoffmann reflex (H-reflex) and the Hmax/Mmax ratio. The original Ashworth scale and ankle range of motion were also measured. The mean HmaxlMmax ratio on the affected side at baseline was high in the study patients. However, there were no statistically significant differences in the HmaxlMmax ratio or in the H-reflex latency between the baseline values and those recorded after therapy intervention. Before treatment, the HmaxlMmax ratio was significantly higher in the affected side than in the unaffected side. However, it was similar at both sides after treatment. Following treatment, the significant reduction in spasticity was clinically detected as measured with the original Ashworth scale. The ankle joint active and passive range of motion was significantly increased. In conclusion, Bobath therapy had a statistically significant effect on the excitability of the aMN in the affected side compared to the unaffected side in stroke patients with muscle spasticity.

  15. A functional assay to measure postsynaptic gamma-aminobutyric acidB responses in cultured spinal cord neurons: Heterologous regulation of the same K+ channel

    Energy Technology Data Exchange (ETDEWEB)

    Kamatchi, G.L.; Ticku, M.K. (Univ. of Texas Health Science Center, San Antonio (USA))

    1991-02-01

    The stimulation of postsynaptic gamma-aminobutyric acid (GABA)B receptors leads to slow inhibitory postsynaptic potentials due to the influx of K(+)-ions. This was studied biochemically, in vitro in mammalian cultured spinal cord neurons by using 86Rb as a substitute for K+. (-)-Baclofen, a GABAB receptor agonist, produced a concentration-dependent increase in the 86Rb-influx. This effect was stereospecific and blocked by GABAB receptor antagonists like CGP 35 348 (3-aminopropyl-diethoxymethyl-phosphonic acid) and phaclofen. Apart from the GABAB receptors, both adenosine via adenosine1 receptors and 5-hydroxytryptamine (5-HT) via 5-HT1 alpha agonists also increased the 86Rb-influx. These agonists failed to show any additivity between them when they were combined in their maximal concentration. In addition, their effect was antagonized specifically by their respective antagonists without influencing the others. These findings suggest the presence of GABAB, adenosine1 and 5-HT1 alpha receptors in the cultured spinal cord neurons, which exhibit a heterologous regulation of the same K(+)-channel. The effect of these agonists were antagonized by phorbol 12,13-didecanoate, an activator of protein kinase C, and pretreatment with pertussis toxin. This suggests that these agonists by acting on their own receptors converge on the same K(+)-channel through the Gi/Go proteins. In summary, we have developed a biochemical functional assay for studying and characterizing GABAB synaptic pharmacology in vitro, using spinal cord neurons.

  16. The Neuroprotective Effect of Alcoholic Extract of Cannabis Sativa on Neuronal Density of Spinal Cord Alpha Motoneurons after Sciatic Nerve Injury in Rats

    Directory of Open Access Journals (Sweden)

    M Tehranipour

    2011-07-01

    Full Text Available Introduction: Injuries of the peripheral nerve system affect the neurons cell body leading to axon injury. Cannabis sativa plant has anti oxidant and anti apoptotic effects. Therefore the aim of present study was to study the neuroprotective effect of alcoholic extract of cannabis sativa leaves on neuronal density of alpha motoneurons in spinal cord after sciatic nerve injury in rats. Methods: In this experimental research, animals were divided into four groups; A: control, B: compression, C: compression+ treatment with 25 mg/kg alcoholic extract, D: compression + treatment with 50 mg/kg extract (n=8. At first, sciatic nerve compression in B, C and D groups was achieved for 60 seconds using locker pincers. Alcoholic extract was injected intra peritoneally in the first and second weeks after compression. Then 28 days after compression, under profusion method, the lumbar spinal cord was sampled and the numerical density in each group was compared with the compression group. The data was analyzed with the use of Minitab 14 software and ANOVA statistical test. Results: Neuronal density showed a meaningful difference in the compression and control groups(P<0.001. Neuronal density in treatment groups(25, 50 mg/kg also had a meaningful increase(P<0.001 as compared to the compression group. Conclusion: Alcoholic extract of cannabis sativa leaves has a neuroprotective effect on spinal cord alpha motoneurons after injury. This could be due to growth and regeneration factors present in the alcoholic extract of cannabis sativa leaves that induce regeneration process in injured neurons or prevent degeneration.

  17. Improvement of neuromuscular synaptic phenotypes without enhanced survival and motor function in severe spinal muscular atrophy mice selectively rescued in motor neurons.

    Directory of Open Access Journals (Sweden)

    Ximena Paez-Colasante

    Full Text Available In the inherited childhood neuromuscular disease spinal muscular atrophy (SMA, lower motor neuron death and severe muscle weakness result from the reduction of the ubiquitously expressed protein survival of motor neuron (SMN. Although SMA mice recapitulate many features of the human disease, it has remained unclear if their short lifespan and motor weakness are primarily due to cell-autonomous defects in motor neurons. Using Hb9(Cre as a driver, we selectively raised SMN expression in motor neurons in conditional SMAΔ7 mice. Unlike a previous study that used choline acetyltransferase (ChAT(Cre+ as a driver on the same mice, and another report that used Hb9(Cre as a driver on a different line of conditional SMA mice, we found no improvement in survival, weight, motor behavior and presynaptic neurofilament accumulation. However, like in ChAT(Cre+ mice, we detected rescue of endplate size and mitigation of neuromuscular junction (NMJ denervation status. The rescue of endplate size occurred in the absence of an increase in myofiber size, suggesting endplate size is determined by the motor neuron in these animals. Real time-PCR showed that the expression of spinal cord SMN transcript was sharply reduced in Hb9(Cre+ SMA mice relative to ChAT(Cre+ SMA mice. This suggests that our lack of overall phenotypic improvement is most likely due to an unexpectedly poor recombination efficiency driven by Hb9(Cre . Nonetheless, the low levels of SMN were sufficient to rescue two NMJ structural parameters indicating that these motor neuron cell autonomous phenotypes are very sensitive to changes in motoneuronal SMN levels. Our results directly suggest that even those therapeutic interventions with very modest effects in raising SMN in motor neurons may provide mitigation of neuromuscular phenotypes in SMA patients.

  18. Resveratrol improves neuron protection and functional recovery through enhancement of autophagy after spinal cord injury in mice

    Science.gov (United States)

    Hu, Jinquan; Han, Hui; Cao, Peng; Yu, Wenchao; Yang, Chen; Gao, Yang; Yuan, Wen

    2017-01-01

    Resveratrol (Res), a natural phenolic compound, has been proven to have a wide variety of beneficial health effects. For example, resveratrol has neuroprotective effects in different central nervous system diseases. However, the mechanisms underlying resveratrol neuroprotection in spinal cord injury (SCI) remain unclear. In this study, we showed that resveratrol treatment improved the restoration of locomotor function, and decreased the degeneration of neurons in SCI mice, which was paralleled by a reduction of apoptosis. We further examined autophagy markers via western blot and immunofluorescence. Results showed that the beneficial effects of resveratrol were related to the promotion LC3II and beclin-1 expression. In addition, autophagy suppression with chloroquine (CQ) partially abolished apoptosis inhibition and locomotor functional improvement of Res on SCI, which indicated that the beneficial effect of resveratrol on SCI was through autophagy enhancement. In conclusion, these results illustrated that the neuroprotective effects of resveratrol in SCI are partially through autophagy stimulation, and implied that Res is a promising drug for SCI therapy. PMID:29118921

  19. DiI-labeling of DRG neurons to study axonal branching in a whole mount preparation of mouse embryonic spinal cord.

    Science.gov (United States)

    Schmidt, Hannes; Rathjen, Fritz G

    2011-12-13

    Here we present a technique to label the trajectories of small groups of DRG neurons into the embryonic spinal cord by diffusive staining using the lipophilic tracer 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). The comparison of axonal pathways of wild-type with those of mouse lines in which genes are mutated allows testing for a functional role of candidate proteins in the control of axonal branching which is an essential mechanism in the wiring of the nervous system. Axonal branching enables an individual neuron to connect with multiple targets, thereby providing the physical basis for the parallel processing of information. Ramifications at intermediate target regions of axonal growth may be distinguished from terminal arborization. Furthermore, different modes of axonal branch formation may be classified depending on whether branching results from the activities of the growth cone (splitting or delayed branching) or from the budding of collaterals from the axon shaft in a process called interstitial branching (Fig. 1). The central projections of neurons from the DRG offer a useful experimental system to study both types of axonal branching: when their afferent axons reach the dorsal root entry zone (DREZ) of the spinal cord between embryonic days 10 to 13 (E10-E13) they display a stereotyped pattern of T- or Y-shaped bifurcation. The two resulting daughter axons then proceed in rostral or caudal directions, respectively, at the dorsolateral margin of the cord and only after a waiting period collaterals sprout from these stem axons to penetrate the gray matter (interstitial branching) and project to relay neurons in specific laminae of the spinal cord where they further arborize (terminal branching). DiI tracings have revealed growth cones at the dorsal root entry zone of the spinal cord that appeared to be in the process of splitting suggesting that bifurcation is caused by splitting of the growth cone itself (Fig. 2), however

  20. Effects of spinal transection on presynaptic markers for glutamatergic neurons in the rat

    International Nuclear Information System (INIS)

    Singer, H.S.; Coyle, J.T.; Frangia, J.; Price, D.L.

    1981-01-01

    To evaluate the hypothesis that glutamic acid may be the neurotransmitter of descending, excitatory supraspinal pathways, the uptake and release of L-[3H] glutamate and the levels of endogenous glutamate were measured in preparations from rat lumbar spinal cord following complete mid-thoracic transection. Following transection, the activity of the synaptosomal high-affinity glutamate uptake process was increased in both dorsal and ventral halves of lumbar cord between 1 and 14 days after transection and returned to control levels by 21 days posttransection. At 7 days, the increased activity of the uptake process for L-[3H]glutamate resulted in elevation of Vmax with no significant alteration in KT as compared to age-matched controls. Depolarization-induced release of L-[3H]glutamate from prelabeled slices did not differ significantly from control in the lesioned rat except at 21 days after lesion when the amount of tritium release was significantly greater in the transected preparations than in control. Amino acid analysis of the lumbar cord from control and transected rats indicated only a 10% decrease in the level of endogenous glutamate and no alterations in the concentration of GABA and glycine 7 days after lesion. These findings do not support the hypothesis that glutamate serves as a major excitatory neurotransmitter in supraspinal pathways innervating the lumbar cord of the rat

  1. Study of Survival Motor Neuron protein regulation and the role of autophagy in Spinal Muscular Atrophy

    OpenAIRE

    Periyakaruppiah, Ambika

    2015-01-01

    L'atròfia muscular espinal (SMA) és un trastorn genètic, causada per la pèrdua o la mutació del gen de la supervivencia de les neurones motores 1 (SMN1), cosa que condueix a una reducció dels nivells de la proteïna SMN i una disfunció selectiva de les MN. S’ha descrit que la reducció d’SMN causa la degeneració de les neurites i la mort cel•lular sense les característiques apoptòtiques clàssiques, però els esdeveniments directes que condueixen a la degeneració de les MN en l’SMA encara són des...

  2. GLT1 overexpression reverses established neuropathic pain-related behavior and attenuates chronic dorsal horn neuron activation following cervical spinal cord injury.

    Science.gov (United States)

    Falnikar, Aditi; Hala, Tamara J; Poulsen, David J; Lepore, Angelo C

    2016-03-01

    Development of neuropathic pain occurs in a major portion of traumatic spinal cord injury (SCI) patients, resulting in debilitating and often long-term physical and psychological burdens. Following SCI, chronic dysregulation of extracellular glutamate homeostasis has been shown to play a key role in persistent central hyperexcitability of superficial dorsal horn neurons that mediate pain neurotransmission, leading to various forms of neuropathic pain. Astrocytes express the major CNS glutamate transporter, GLT1, which is responsible for the vast majority of functional glutamate uptake, particularly in the spinal cord. In our unilateral cervical contusion model of mouse SCI that is associated with ipsilateral forepaw heat hypersensitivity (a form of chronic at-level neuropathic pain-related behavior), we previously reported significant and long-lasting reductions in GLT1 expression and functional GLT1-mediated glutamate uptake in cervical spinal cord dorsal horn. To therapeutically address GLT1 dysfunction following cervical contusion SCI, we injected an adeno-associated virus type 8 (AAV8)-Gfa2 vector into the superficial dorsal horn to increase GLT1 expression selectively in astrocytes. Compared to both contusion-only animals and injured mice that received AAV8-eGFP control injection, AAV8-GLT1 delivery increased GLT1 protein expression in astrocytes of the injured cervical spinal cord dorsal horn, resulting in a significant and persistent reversal of already-established heat hypersensitivity. Furthermore, AAV8-GLT1 injection significantly reduced expression of the transcription factor and marker of persistently increased neuronal activation, ΔFosB, in superficial dorsal horn neurons. These results demonstrate that focal restoration of GLT1 expression in the superficial dorsal horn is a promising target for treating chronic neuropathic pain following SCI. © 2015 Wiley Periodicals, Inc.

  3. Repetitive treatment with diluted bee venom reduces neuropathic pain via potentiation of locus coeruleus noradrenergic neuronal activity and modulation of spinal NR1 phosphorylation in rats.

    Science.gov (United States)

    Kang, Suk-Yun; Roh, Dae-Hyun; Yoon, Seo-Yeon; Moon, Ji-Young; Kim, Hyun-Woo; Lee, Hye-Jung; Beitz, Alvin J; Lee, Jang-Hern

    2012-02-01

    We previously demonstrated that a single injection of diluted bee venom (DBV) temporarily alleviates thermal hyperalgesia, but not mechanical allodynia, in neuropathic rats. The present study was designed to determine whether repetitive injection of DBV produces more potent analgesic effects on neuropathy-induced nociception and whether those effects are associated with increased neuronal activity in the locus coeruleus (LC) and with the suppression of spinal NMDA receptor NR1 subunit phosphorylation (pNR1). DBV (.25 mg/kg) was administered subcutaneously twice a day for 2 weeks beginning on day 15 post-chronic constrictive injury surgery. Pain responses were examined and potential changes in LC Fos expression and spinal pNR1 expression were determined. Repetitive DBV administration significantly reduced mechanical allodynia, as well as thermal hyperalgesia. The activity of LC noradrenergic neurons was increased and spinal pNR1 expression was significantly suppressed by repetitive DBV as compared with those of vehicle or single DBV injection. These suppressive effects of repetitive DBV on neuropathic pain and spinal pNR1 were prevented by intrathecal pretreatment of idazoxan, an alpha-2 adrenoceptor antagonist. These results indicate that repetitive DBV produces potent analgesic effects on neuropathic pain and this is associated with the activation of the LC noradrenergic system and with a reduction in spinal pNR1. The results of current study demonstrate that repetitive administration of DBV significantly suppresses neuropathic pain. Furthermore, this study provides mechanistic information that repetitive treatment of DBV can produce more potent analgesic effect than single DBV treatment, indicating a potential novel strategy for the management of chronic pain. Copyright © 2012 American Pain Society. Published by Elsevier Inc. All rights reserved.

  4. Spinal neuronal correlates of tapentadol analgesia in cancer pain: A back-translational approach

    DEFF Research Database (Denmark)

    Falk, Sarah; Patel, Ryan; Heegaard, Anne-Marie

    2015-01-01

    Background Pain is a common and highly debilitating complication for cancer patients significantly compromising their quality of life. Cancer-induced bone pain involves a complex interplay of multiple mechanisms including both inflammatory and neuropathic processes and also some unique changes. S...... to the mechanistic understanding of cancer-induced bone pain and support the sparse clinical data indicating a possible use of the drug as a therapeutic alternative for cancer patients with metastatic pain complication........ Strong opioids are a mainstay of treatments but side effects are problematic and can compromise optimal pain control. Tapentadol is a novel dual-action drug, both stimulating inhibitory μ-opioid receptors (MOR) and mediating noradrenaline reuptake inhibition (NRI) leading to activation of the inhibitory...... of the neuronal activity with efficacy against mechanical, thermal and electrically evoked activity following tapentadol administration. In addition, the effects of the drug were fully reversible by naloxone and partly by atipamezole, supporting the idea of MOR-NRI dual actions. Conclusions These findings add...

  5. ZL006 protects spinal cord neurons against ischemia-induced oxidative stress through AMPK-PGC-1α-Sirt3 pathway.

    Science.gov (United States)

    Liu, Shu-Guang; Wang, Yun-Mei; Zhang, Yan-Jun; He, Xi-Jing; Ma, Tao; Song, Wei; Zhang, Yu-Min

    2017-09-01

    Spinal cord ischemia (SCI) induces a range of cellular and molecular cascades, including activation of glutamate receptors and downstream signaling. Post-synaptic density protein 95 (PSD-95) links neuronal nitric oxide synthase (nNOS) with the N-methyl-d-aspartic acid (NMDA) receptors to form a ternary complex in the CNS. This molecular complex-mediated cytotoxicity has been implicated in brain ischemia, but its role in SCI has not been determined. The goal of the study was to investigate the potential protective effects of ZL006, a small-molecule inhibitor of the PSD-95/nNOS interaction, in an in vitro SCI model induced by oxygen and glucose deprivation (OGD) in cultured spinal cord neurons. We found that ZL006 reduced OGD-induced lactate dehydrogenase (LDH) release, neuronal apoptosis and loss of cell viability. This protection was accompanied by the preservation of mitochondrial function, as evidenced by reduced mitochondrial oxidative stress, attenuated mitochondrial membrane potential (MMP) loss, and enhanced ATP generation. In addition, ZL006 stimulated mitochondrial enzyme activities and SOD2 deacetylation in a Sirt3-dependent manner. The results of western blot analysis showed that ZL006 increased the activation of AMPK-PGC-1α-Sirt3 pathway, and the beneficial effects of ZL006 was partially abolished by AMPK inhibitor and PGC-1α knockdown. Therefore, our present data showed that, by the AMPK-PGC-1α-Sirt3 pathway, ZL006 protects spinal cord neurons against ischemia through reducing mitochondrial oxidative stress to prevent apoptosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The spinal muscular atrophy with pontocerebellar hypoplasia gene VRK1 regulates neuronal migration through an amyloid-β precursor protein-dependent mechanism.

    Science.gov (United States)

    Vinograd-Byk, Hadar; Sapir, Tamar; Cantarero, Lara; Lazo, Pedro A; Zeligson, Sharon; Lev, Dorit; Lerman-Sagie, Tally; Renbaum, Paul; Reiner, Orly; Levy-Lahad, Ephrat

    2015-01-21

    Spinal muscular atrophy with pontocerebellar hypoplasia (SMA-PCH) is an infantile SMA variant with additional manifestations, particularly severe microcephaly. We previously identified a nonsense mutation in Vaccinia-related kinase 1 (VRK1), R358X, as a cause of SMA-PCH. VRK1-R358X is a rare founder mutation in Ashkenazi Jews, and additional mutations in patients of different origins have recently been identified. VRK1 is a nuclear serine/threonine protein kinase known to play multiple roles in cellular proliferation, cell cycle regulation, and carcinogenesis. However, VRK1 was not known to have neuronal functions before its identification as a gene mutated in SMA-PCH. Here we show that VRK1-R358X homozygosity results in lack of VRK1 protein, and demonstrate a role for VRK1 in neuronal migration and neuronal stem cell proliferation. Using shRNA in utero electroporation in mice, we show that Vrk1 knockdown significantly impairs cortical neuronal migration, and affects the cell cycle of neuronal progenitors. Expression of wild-type human VRK1 rescues both proliferation and migration phenotypes. However, kinase-dead human VRK1 rescues only the migration impairment, suggesting the role of VRK1 in neuronal migration is partly noncatalytic. Furthermore, we found that VRK1 deficiency in human and mouse leads to downregulation of amyloid-β precursor protein (APP), a known neuronal migration gene. APP overexpression rescues the phenotype caused by Vrk1 knockdown, suggesting that VRK1 affects neuronal migration through an APP-dependent mechanism. Copyright © 2015 the authors 0270-6474/15/350936-08$15.00/0.

  7. VGLUT1 or VGLUT2 mRNA-positive neurons in spinal trigeminal nucleus provide collateral projections to both the thalamus and the parabrachial nucleus in rats.

    Science.gov (United States)

    Zhang, Chun-Kui; Li, Zhi-Hong; Qiao, Yu; Zhang, Ting; Lu, Ya-Cheng; Chen, Tao; Dong, Yu-Lin; Li, Yun-Qing; Li, Jin-Lian

    2018-04-12

    The trigemino-thalamic (T-T) and trigemino-parabrachial (T-P) pathways are strongly implicated in the sensory-discriminative and affective/emotional aspects of orofacial pain, respectively. These T-T and T-P projection fibers originate from the spinal trigeminal nucleus (Vsp). We previously determined that many vesicular glutamate transporter (VGLUT1 and/or VGLUT2) mRNA-positive neurons were distributed in the Vsp of the adult rat, and most of these neurons sent their axons to the thalamus or cerebellum. However, whether VGLUT1 or VGLUT2 mRNA-positive projection neurons exist that send their axons to both the thalamus and the parabrachial nucleus (PBN) has not been reported. Thus, in the present study, dual retrograde tract tracing was used in combination with fluorescence in situ hybridization (FISH) for VGLUT1 or VGLUT2 mRNA to identify the existence of VGLUT1 or VGLUT2 mRNA neurons that send collateral projections to both the thalamus and the PBN. Neurons in the Vsp that send collateral projections to both the thalamus and the PBN were mainly VGLUT2 mRNA-positive, with a proportion of 90.3%, 93.0% and 85.4% in the oral (Vo), interpolar (Vi) and caudal (Vc) subnucleus of the Vsp, respectively. Moreover, approximately 34.0% of the collateral projection neurons in the Vc showed Fos immunopositivity after injection of formalin into the lip, and parts of calcitonin gene-related peptide (CGRP)-immunopositive axonal varicosities were in direct contact with the Vc collateral projection neurons. These results indicate that most collateral projection neurons in the Vsp, particularly in the Vc, which express mainly VGLUT2, may relay orofacial nociceptive information directly to the thalamus and PBN via axon collaterals.

  8. Time-Dependent Increases in Protease Activities for Neuronal Apoptosis in Spinal Cords of Lewis Rats During Development of Acute Experimental Autoimmune Encephalomyelitis

    Science.gov (United States)

    Das, Arabinda; Guyton, M. Kelly; Matzelle, Denise D.; Ray, Swapan K.; Banik, Naren L.

    2008-01-01

    Multiple sclerosis (MS) is characterized by axonal demyelination and neurodegeneration, the latter having been inadequately explored in the MS animal model experimental autoimmune encephalomyelitis (EAE). The purpose of this study was to examine the time-dependent correlation between increased calpain and caspase activities and neurodegeneration in spinal cord tissues from Lewis rats with acute EAE. An increase in TUNEL-positive neurons and internucleosomal DNA fragmentation in EAE spinal cords suggested that neuronal death was a result of apoptosis on days 8–10 following induction of EAE. Increases in calpain expression in EAE correlated with activation of pro-apoptotic proteases, leading to apoptotic cell death beginning on day 8 of EAE, which occurred before the appearance of visible clinical symptoms. Increases in calcineurin expression and decreases in phospho-Bad (p-Bad) suggested Bad activation in apoptosis during acute EAE. Increases in the Bax:Bcl-2 ratio and activation of caspase-9 showed the involvement of mitochondria in apoptosis. Further, caspase-8 activation suggested induction of the death receptor–mediated pathway for apoptosis. Endoplasmic reticulum stress leading to caspase-3 activation was also observed, indicating that multiple apoptotic pathways were activated following EAE induction. In contrast, cell death was mostly a result of necrosis on the later day (day 11), when EAE entered a severe stage. From these findings, we conclude that increases in calpain and caspase activities play crucial roles in neuronal apoptosis during the development of acute EAE. PMID:18521931

  9. Deletion of mammalian sterile 20-like kinase 1 attenuates neuronal loss and improves locomotor function in a mouse model of spinal cord trauma.

    Science.gov (United States)

    Wang, Pan-Feng; Xu, Da-Yuan; Zhang, Yuntong; Liu, Xiao-Bin; Xia, Yan; Zhou, Pan-Yu; Fu, Qing-Ge; Xu, Shuo-Gui

    2017-07-01

    Neuronal cell death following spinal cord injury (SCI) is an important contributor to neurological deficits. The purpose of our work was to delineate the function of mammalian sterile 20-like kinase 1 (Mst1), a pro-apoptotic kinase and key mediator of apoptotic signaling, in the pathogenesis of an experimental mouse model of SCI. Male mice received a mid-thoracic spinal contusion injury, and it was found that phosphorylation of Mst1 at the injured site was enhanced significantly following SCI. Furthermore, when compared to the wild-type controls, Mst1-deficient mice displayed improved locomotor function by increased Basso mouse scale score. Deletion of Mst1 in mice attenuated loss of motor neurons and suppressed microglial and glial activation following SCI. Deletion of Mst1 in mice reduced apoptosis via suppressing cytochrome c release and caspase-3 activation following SCI. Deletion of Mst1 attenuated mitochondrial dysfunction and increased ATP formation following SCI. Deletion of Mst1 in mice inhibited local inflammation following SCI, evidenced by reduced activities of myeloperoxidase and protein levels of TNF-α, IL-1β, and IL-6. In conclusion, the present study demonstrated that deletion of Mst1 attenuated neuronal loss and improved locomotor function in a mouse model of SCI, via preserving mitochondrial function, attenuating mitochondria-mediated apoptotic pathway, and suppressing inflammation, at least in part.

  10. Glycine receptor in rat hippocampal and spinal cord neurons as a molecular target for rapid actions of 17-β-estradiol

    Directory of Open Access Journals (Sweden)

    Liu Chun-Feng

    2009-01-01

    Full Text Available Abstract Glycine receptors (GlyRs play important roles in regulating hippocampal neural network activity and spinal nociception. Here we show that, in cultured rat hippocampal (HIP and spinal dorsal horn (SDH neurons, 17-β-estradiol (E2 rapidly and reversibly reduced the peak amplitude of whole-cell glycine-activated currents (IGly. In outside-out membrane patches from HIP neurons devoid of nuclei, E2 similarly inhibited IGly, suggesting a non-genomic characteristic. Moreover, the E2 effect on IGly persisted in the presence of the calcium chelator BAPTA, the protein kinase inhibitor staurosporine, the classical ER (i.e. ERα and ERβ antagonist tamoxifen, or the G-protein modulators, favoring a direct action of E2 on GlyRs. In HEK293 cells expressing various combinations of GlyR subunits, E2 only affected the IGly in cells expressing α2, α2β or α3β subunits, suggesting that either α2-containing or α3β-GlyRs mediate the E2 effect observed in neurons. Furthermore, E2 inhibited the GlyR-mediated tonic current in pyramidal neurons of HIP CA1 region, where abundant GlyR α2 subunit is expressed. We suggest that the neuronal GlyR is a novel molecular target of E2 which directly inhibits the function of GlyRs in the HIP and SDH regions. This finding may shed new light on premenstrual dysphoric disorder and the gender differences in pain sensation at the CNS level.

  11. Neuronal loss and decreased GLT-1 expression observed in the spinal cord of Pembroke Welsh Corgi dogs with canine degenerative myelopathy.

    Science.gov (United States)

    Ogawa, M; Uchida, K; Yamato, O; Inaba, M; Uddin, M M; Nakayama, H

    2014-05-01

    Canine degenerative myelopathy (DM) is a progressive neurodegenerative disease that is frequently found in Pembroke Welsh Corgi (PWC) dogs. Canine DM is potentially a spontaneous animal model for human amyotrophic lateral sclerosis (ALS) because of similar lesions and the involvement of superoxide dismutase 1 (SOD1) mutation. However, the ventral horn lesion in DM has not been characterized in detail. Glutamate excitotoxicity due to deficiency of the glutamine-glutamate cycle has been implicated in neuron death in ALS. Thus, we examined 5 PWC dogs with an SOD1 mutation that were affected by DM, 5 non-DM PWC dogs, and 5 Beagle dogs without neurologic signs to assess the neuronal changes and the expression levels of 2 glial excitatory amino acid transporters (glutamate transporter 1 [GLT-1] and glutamate/aspartate transporter [GLAST]). The number of neurons in the spinal ventral horns of the DM dogs was significantly decreased, whereas no change was found in the cell size. Chromatolysis, lipofuscin-laden neurons, and marked synapse loss were also observed. GLT-1 expression was strikingly decreased in DM dogs, whereas GLAST expression showed no significant change. The results indicate that excitotoxicity related to the reduced expression of GLT-1, but not GLAST, may be involved in neuron loss in DM, as in human ALS, whereas intraneuronal events may differ between the 2 diseases.

  12. Light touch induces ERK activation in superficial dorsal horn neurons after inflammation: involvement of spinal astrocytes and JNK signaling in touch-evoked central sensitization and mechanical allodynia

    Science.gov (United States)

    Gao, Yong-Jing; Ji, Ru-Rong

    2010-01-01

    Activation of extracellular signal-regulated kinase (ERK) in spinal cord neurons could serve as a marker for sensitization of dorsal horn neurons in persistent pain. ERK is normally activated by high-threshold noxious stimuli. We investigated how low-threshold mechanical stimuli could activate ERK after complete Freund’s adjuvant (CFA)-induced inflammation. Unilateral injection of CFA induced ipsilateral heat hyperalgesia and bilateral mechanical allodynia. CFA-induced ERK activation in ipsilateral dorsal horn neurons declined after 2 days. Interestingly, low threshold mechanical stimulation given by light touch either on the inflamed paw or the contralateral non-inflamed paw dramatically increased ERK phosphorylation (pERK) in the dorsal horn ipsilateral to touch stimulation. Notably, light touch induced pERK mainly in superficial neurons in laminae I-IIo. Intrathecal administration of the astroglial toxin L-α-aminoadipate (L-α-AA) on post-CFA day 2 reversed CFA-induced bilateral mechanical allodynia but not heat hyperalgesia. Furthermore, L-α-AA, the glial inhibitor fluorocitrate, and a peptide inhibitor of c-Jun N-terminal Kinase (JNK) all reduced light touch-evoked ERK activation ipsilateral to touch. Collectively, these data suggest that (a) ERK can be activated in superficial dorsal horn neurons by low threshold mechanical stimulation under pathological condition and (b) ERK activation by light touch is associated with mechanical allodynia and requires an astrocyte network. PMID:20722971

  13. Production of high quality brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) RNA from isolated populations of rat spinal cord motor neurons obtained by Laser Capture Microdissection (LCM).

    Science.gov (United States)

    Mehta, Prachi; Premkumar, Brian; Morris, Renée

    2016-08-03

    The mammalian central nervous system (CNS) is composed of multiple cellular elements, making it challenging to segregate one particular cell type to study their gene expression profile. For instance, as motor neurons represent only 5-10% of the total cell population of the spinal cord, meaningful transcriptional analysis on these neurons is almost impossible to achieve from homogenized spinal cord tissue. A major challenge faced by scientists is to obtain good quality RNA from small amounts of starting material. In this paper, we used Laser Capture Microdissection (LCM) techniques to identify and isolate spinal cord motor neurons. The present analysis revealed that perfusion with paraformaldehyde (PFA) does not alter RNA quality. RNA integrity numbers (RINs) of tissue samples from rubrospinal tract (RST)-transected, intact spinal cord or from whole spinal cord homogenate were all above 8, which indicates intact, high-quality RNA. Levels of mRNA for brain-derived neurotrophic factor (BDNF) or for its tropomyosin receptor kinase B (TrkB) were not affected by rubrospinal tract (RST) transection, a surgical procedure that deprive motor neurons from one of their main supraspinal input. The isolation of pure populations of neurons with LCM techniques allows for robust transcriptional characterization that cannot be achieved with spinal cord homogenates. Such preparations of pure population of motor neurons will provide valuable tools to advance our understanding of the molecular mechanisms underlying spinal cord injury and neuromuscular diseases. In the near future, LCM techniques might be instrumental to the success of gene therapy for these debilitating conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Enhancement by interleukin-1β of AMPA and NMDA receptor-mediated currents in adult rat spinal superficial dorsal horn neurons.

    Science.gov (United States)

    Liu, Tao; Jiang, Chang-Yu; Fujita, Tsugumi; Luo, Shi-Wen; Kumamoto, Eiichi

    2013-03-28

    Proinflammatory cytokine interleukin-1β (IL-1β) released from spinal microglia plays an important role in the maintenance of acute and chronic pain states. However, the cellular basis of this action remains poorly understood. Using whole-cell patch-clamp recordings, we examined the action of IL-1β on AMPA- and NMDA-receptor-mediated currents recorded from substantia gelatinosa (SG) neurons of adult rat spinal cord slices which are key sites for regulating nociceptive transmission from the periphery. AMPA- and NMDA-induced currents were increased in peak amplitude by IL-1β in a manner different from each other in SG neurons. These facilitatory actions of IL-1β were abolished by IL-1 receptor (IL-1R) antagonist (IL-1ra), which by itself had no detectable effects on AMPA- and NMDA-induced currents. The AMPA- but not NMDA-induced current facilitated by IL-1β was recovered to control level 30 min after IL-1β washout and largely depressed in Na+-channel blocker tetrodotoxin-containing or nominally Ca2+-free Krebs solution. Minocycline, a microglia inhibitor, blocked the facilitatory effect of IL-1β on AMPA- but not NMDA-induced currents, where minocycline itself depressed NMDA- but had not any effects on AMPA-induced currents. IL-1β enhances AMPA and NMDA responses in SG neurons through IL-1R activation; the former but not latter action is reversible and due to an increase in neuronal activity in a manner dependent on extracellular Ca2+ and minocycline. It is suggested that AMPA and NMDA receptors are positively modulated by IL-1β in a manner different from each other; the former but not latter is mediated by a neurotransmitter released as a result of an increase in neuronal activity. Since IL-1β contributes to nociceptive behavior induced by peripheral nerve or tissue injury, the present findings also reveal an important cellular link between neuronal and glial cells in the spinal dorsal horn.

  15. Repeated touch and needle-prick stimulation in the neonatal period increases the baseline mechanical sensitivity and postinjury hypersensitivity of adult spinal sensory neurons.

    Science.gov (United States)

    van den Hoogen, Nynke J; Patijn, Jacob; Tibboel, Dick; Joosten, Bert A; Fitzgerald, Maria; Kwok, Charlie H T

    2018-03-08

    Noxious stimulation at critical stages of development has long-term consequences on somatosensory processing in later life, but it is not known whether this developmental plasticity is restricted to nociceptive pathways. Here, we investigate the effect of repeated neonatal noxious or innocuous hind paw stimulation on adult spinal dorsal horn cutaneous mechanical sensitivity. Neonatal Sprague-Dawley rats of both sexes received 4 unilateral left hind paw needle pricks (NPs, n = 13) or 4 tactile (cotton swab touch) stimuli, per day (TC, n = 11) for the first 7 days of life. Control pups were left undisturbed (n = 17). When adult (6-8 weeks), lumbar wide-dynamic-range neuron activity in laminae III-V was recorded using in vivo extracellular single-unit electrophysiology. Spike activity evoked by cutaneous dynamic tactile (brush), pinch and punctate (von Frey hair) stimulation, and plantar receptive field areas were recorded, at baseline and 2 and 5 days after left plantar hind paw incision. Baseline brush receptive fields, von Frey hair, and pinch sensitivity were significantly enhanced in adult NP and TC animals compared with undisturbed controls, although effects were greatest in NP rats. After incision, injury sensitivity of adult wide-dynamic-range neurons to both noxious and dynamic tactile hypersensitivity was significantly greater in NP animals compared with TC and undisturbed controls. We conclude that both repeated touch and needle-prick stimulation in the neonatal period can alter adult spinal sensory neuron sensitivity to both innocuous and noxious mechanical stimulation. Thus, spinal sensory circuits underlying touch and pain processing are shaped by a range of early-life somatosensory experiences.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

  16. Long-term modulation of the intrinsic cardiac nervous system by spinal cord neurons in normal and ischaemic hearts

    NARCIS (Netherlands)

    Armour, JA; Linderoth, B; Arora, RC; DeJongste, MJL; Ardell, JL; Kingma, JG; Hill, M; Foreman, RD

    2002-01-01

    Electrical excitation of the dorsal aspect of the rostral thoracic spinal cord imparts long-term therapeutic benefits to patients with angina pectoris. Such spinal cord stimulation also induces short-term suppressor effects on the intrinsic cardiac nervous system. The purpose of this study was to

  17. Quantification, by solid-phase minisequencing, of the telomeric and centromeric copies of the survival motor neuron gene in families with spinal muscular atrophy

    DEFF Research Database (Denmark)

    Schwartz, M; Sørensen, N; Hansen, F J

    1997-01-01

    In an analysis of 30 families affected by spinal muscular atrophy (SMA) we have used the solid-phase minisequencing method to determine the ratio between the number of telomeric and centromeric copies of the survival motor neuron gene (SMN and cBCD541 respectively) on normal and SMA chromosomes...... the hypothesis that the presence of more copies of cBCD541 is correlated to a less severe course of the disease. The frequencies of haplotypes characterized by having 0, 1, or 2 copies, respectively, of cBCD541 were found to differ significantly between normal and SMA chromosomes. This distribution can...

  18. How microelectrode array-based chick forebrain neuron biosensors respond to glutamate NMDA receptor antagonist AP5 and GABAA receptor antagonist musimol

    Directory of Open Access Journals (Sweden)

    Serena Y. Kuang

    2016-09-01

    Full Text Available We have established a long-term, stable primary chick forebrain neuron (FBN culture on a microelectrode array platform as a biosensor system for neurotoxicant screening and for neuroelectrophysiological studies for multiple purposes. This paper reports some of our results, which characterize the biosensor pharmacologically. Dose-response experiments were conducted using NMDA receptor antagonist AP5 and GABAA receptor agonist musimol (MUS. The chick FBN biosensor (C-FBN-biosensor responds to the two agents in a pattern similar to that of rodent counterparts; the estimated EC50s (the effective concentration that causes 50% inhibition of the maximal effect are 2.3 μM and 0.25 μM, respectively. Intercultural and intracultural reproducibility and long-term reusability of the C-FBN-biosensor are addressed and discussed. A phenomenon of sensitization of the biosensor that accompanies intracultural reproducibility in paired dose-response experiments for the same agent (AP5 or MUS is reported. The potential application of the C-FBN-biosensor as an alternative to rodent biosensors in shared sensing domains (NMDA receptor and GABAA receptor is suggested. Keywords: Biosensor, Microelectrode array, Neurotoxicity, Chick forebrain neuron, AP5, Musimol

  19. Autologous adipose-derived stem cells attenuate muscular atrophy and protect spinal cord ventral horn motor neurons in an animal model of burn injury.

    Science.gov (United States)

    Wu, Sheng-Hua; Huang, Shu-Hung; Lo, Yi-Ching; Chai, Chee-Yin; Lee, Su-Shin; Chang, Kao-Ping; Lin, Sin-Daw; Lai, Chung-Sheng; Yeh, Jwu-Lai; Kwan, Aij-Lie

    2015-08-01

    Burn injuries might increase muscle mass loss, but the mechanisms are still unclear. In this study, we demonstrated that burn injury induced spinal cord ventral horn motor neuron (VHMN) apoptosis and subsequently caused muscle atrophy and revealed the potential protection of autologous adipose-derived stem cells (ASCs) transplantation on spinal cord VHMNs and muscle against burn injury. Third-degree hind-paw burns were established by contact with a 75°C metal surface for 10 seconds. Adipose tissues were harvested from the groin fat pad, expanded in culture and labeled with chloromethyl-benzamido/1,1'-dioctadecyl-3,3,3',3'- tetramethyl indocarbocyanine perchlorate. The ASCs were transplanted into the injured hind paw at 4 weeks after burn injury. The lumbar spinal cord, sciatic nerve, gastrocnemius muscle and hind-paw skin were processed for immunofluorescent staining at 4 weeks after transplantation, including terminal deoxynucleotidyl transferase (TUNEL) assay, caspase-3, caspase-9, CD 90 and S100, and the gastrocnemius muscle was evaluated through the use of hematoxylin and eosin staining. Caspase-3-positive, caspase-9-positive and TUNEL-positive cells were significantly increased in the corresponding dermatome spinal cord VHMNs after burn injury. Moreover, the decrease of Schwann cells in sciatic nerve and the increase of denervation atrophy in gastrocnemius muscle were observed. Furthermore, ASCs transplantation significantly attenuated apoptotic death of VHMNs and the area of muscle denervation atrophy in the gastrocnemius muscle fibers. The animal model of third-degree burns in the hind paw showed significant apoptosis in the corresponding spinal cord VHMNs, which suggests that neuroprotection might be the potentially therapeutic target in burn-induced muscle atrophy. ASCs have potential neuroprotection against burn injuries through its anti-apoptotic effects. Copyright © 2015. Published by Elsevier Inc.

  20. Synaptic NMDA receptor-dependent Ca²⁺ entry drives membrane potential and Ca²⁺ oscillations in spinal ventral horn neurons.

    Science.gov (United States)

    Alpert, Michael H; Alford, Simon

    2013-01-01

    During vertebrate locomotion, spinal neurons act as oscillators when initiated by glutamate release from descending systems. Activation of NMDA receptors initiates Ca²⁺-mediated intrinsic membrane potential oscillations in central pattern generator (CPG) neurons. NMDA receptor-dependent intrinsic oscillations require Ca²⁺-dependent K⁺ (K(Ca)2) channels for burst termination. However, the location of Ca²⁺ entry mediating K(Ca)2 channel activation, and type of Ca²⁺ channel--which includes NMDA receptors and voltage-gated Ca²⁺ channels (VGCCs)--remains elusive. NMDA receptor-dependent Ca²⁺ entry necessitates presynaptic release of glutamate, implying a location at active synapses within dendrites, whereas VGCC-dependent Ca²⁺ entry is not similarly constrained. Where Ca²⁺ enters relative to K(Ca)2 channels is crucial to information processing of synaptic inputs necessary to coordinate locomotion. We demonstrate that Ca²⁺ permeating NMDA receptors is the dominant source of Ca²⁺ during NMDA-dependent oscillations in lamprey spinal neurons. This Ca²⁺ entry is synaptically located, NMDA receptor-dependent, and sufficient to activate K(Ca)2 channels at excitatory interneuron synapses onto other CPG neurons. Selective blockade of VGCCs reduces whole-cell Ca²⁺ entry but leaves membrane potential and Ca²⁺ oscillations unaffected. Furthermore, repetitive oscillations are prevented by fast, but not slow, Ca²⁺ chelation. Taken together, these results demonstrate that K(Ca)2 channels are closely located to NMDA receptor-dependent Ca²⁺ entry. The close spatial relationship between NMDA receptors and K(Ca)2 channels provides an intrinsic mechanism whereby synaptic excitation both excites and subsequently inhibits ventral horn neurons of the spinal motor system. This places the components necessary for oscillation generation, and hence locomotion, at glutamatergic synapses.

  1. Motor neuronal repletion of the NMJ organizer, Agrin, modulates the severity of the spinal muscular atrophy disease phenotype in model mice.

    Science.gov (United States)

    Kim, Jeong-Ki; Caine, Charlotte; Awano, Tomoyuki; Herbst, Ruth; Monani, Umrao R

    2017-07-01

    Spinal muscular atrophy (SMA) is a common and often fatal neuromuscular disorder caused by low levels of the Survival Motor Neuron (SMN) protein. Amongst the earliest detectable consequences of SMN deficiency are profound defects of the neuromuscular junctions (NMJs). In model mice these synapses appear disorganized, fail to mature and are characterized by poorly arborized nerve terminals. Given one role of the SMN protein in orchestrating the assembly of spliceosomal snRNP particles and subsequently regulating the alternative splicing of pre-mRNAs, a plausible link between SMN function and the distal neuromuscular SMA phenotype is an incorrectly spliced transcript or transcripts involved in establishing or maintaining NMJ structure. In this study, we explore the effects of one such transcript-Z+Agrin-known to be a critical organizer of the NMJ. We confirm that low SMN protein reduces motor neuronal levels of Z+Agrin. Repletion of this isoform of Agrin in the motor neurons of SMA model mice increases muscle fiber size, enhances the post-synaptic NMJ area, reduces the abnormal accumulation of intermediate filaments in nerve terminals of the neuromuscular synapse and improves the innervation of muscles. While these effects are independent of changes in SMN levels or increases in motor neuron numbers they nevertheless have a significant effect on the overall disease phenotype, enhancing mean survival in severely affected SMA model mice by ∼40%. We conclude that Agrin is an important target of the SMN protein and that mitigating NMJ defects may be one strategy in treating human spinal muscular atrophy. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Early neonatal loss of inhibitory synaptic input to the spinal motor neurons confers spina bifida-like leg dysfunction in a chicken model

    Directory of Open Access Journals (Sweden)

    Md. Sakirul Islam Khan

    2017-12-01

    Full Text Available Spina bifida aperta (SBA, one of the most common congenital malformations, causes lifelong neurological complications, particularly in terms of motor dysfunction. Fetuses with SBA exhibit voluntary leg movements in utero and during early neonatal life, but these disappear within the first few weeks after birth. However, the pathophysiological sequence underlying such motor dysfunction remains unclear. Additionally, because important insights have yet to be obtained from human cases, an appropriate animal model is essential. Here, we investigated the neuropathological mechanisms of progression of SBA-like motor dysfunctions in a neural tube surgery-induced chicken model of SBA at different pathogenesis points ranging from embryonic to posthatch ages. We found that chicks with SBA-like features lose voluntary leg movements and subsequently exhibit lower-limb paralysis within the first 2 weeks after hatching, coinciding with the synaptic change-induced disruption of spinal motor networks at the site of the SBA lesion in the lumbosacral region. Such synaptic changes reduced the ratio of inhibitory-to-excitatory inputs to motor neurons and were associated with a drastic loss of γ-aminobutyric acid (GABAergic inputs and upregulation of the cholinergic activities of motor neurons. Furthermore, most of the neurons in ventral horns, which appeared to be suffering from excitotoxicity during the early postnatal days, underwent apoptosis. However, the triggers of cellular abnormalization and neurodegenerative signaling were evident in the middle- to late-gestational stages, probably attributable to the amniotic fluid-induced in ovo milieu. In conclusion, we found that early neonatal loss of neurons in the ventral horn of exposed spinal cord affords novel insights into the pathophysiology of SBA-like leg dysfunction.

  3. Distinct membrane effects of spinal nerve ligation on injured and adjacent dorsal root ganglion neurons in rats

    NARCIS (Netherlands)

    Sapunar, Damir; Ljubkovic, Marko; Lirk, Philipp; McCallum, J. Bruce; Hogan, Quinn H.

    2005-01-01

    Painful peripheral nerve injury results in disordered sensory neuron function that contributes to the pathogenesis of neuropathic pain. However, the relative roles of neurons with transected axons versus intact adjacent neurons have not been resolved. An essential first step is identification of

  4. Phosphorylation of ERK in neurokinin 1 receptor-expressing neurons in laminae III and IV of the rat spinal dorsal horn following noxious stimulation

    Directory of Open Access Journals (Sweden)

    Watanabe Masahiko

    2007-02-01

    Full Text Available Abstract Background There is a population of large neurons with cell bodies in laminae III and IV of the spinal dorsal horn which express the neurokinin 1 receptor (NK1r and have dendrites that enter the superficial laminae. Although it has been shown that these are all projection neurons and that they are innervated by substance P-containing (nociceptive primary afferents, we know little about their responses to noxious stimuli. In this study we have looked for phosphorylation of extracellular signal-regulated kinases (ERKs in these neurons in response to different types of noxious stimulus applied to one hindlimb of anaesthetised rats. The stimuli were mechanical (repeated pinching, thermal (immersion in water at 52°C or chemical (injection of 2% formaldehyde. Results Five minutes after each type of stimulus we observed numerous cells with phosphorylated ERK (pERK in laminae I and IIo, together with scattered positive cells in deeper laminae. We found that virtually all of the lamina III/IV NK1r-immunoreactive neurons contained pERK after each of these stimuli and that in the great majority of cases there was internalisation of the NK1r on the dorsal dendrites of these cells. In addition, we also saw neurons in lamina III that were pERK-positive but lacked the NK1r, and these were particularly evident in animals that had had the pinch stimulus. Conclusion Our results demonstrate that lamina III/IV NK1r-immunoreactive neurons show receptor internalisation and ERK phosphorylation after mechanical, thermal or chemical noxious stimuli.

  5. Glial-glial and glial-neuronal interfaces in radiation-induced, glia-depleted spinal cord

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, S.A.; Sims, T.J. [Arkansas Univ., Little Rock, AR (United States). Medical Center

    1997-01-01

    This review summarises some of the major findings derived from studies using the model of a glia-depleted environment developed and characterised in this laboratory. Glial depletion is achieved by exposure of the immature rodent spinal cord to x-radiation which markedly reduces both astrocyte and oligodendrocyte populations and severely impairs myelination. This glia-depleted, hypomylinated state presents a unique opportunity to examine aspects of spinal cord maturation in the absence of a normal glial population. An associated sequela within 2-3 wk following irradiation is the appearance of Schwann cells in the dorsal portion of the spinal cord. Characteristics of these intraspinal Schwann cells, their patterns of myelination or ensheathment, and their interrelations with the few remaining central glia have been examined. A later sequela is the development of Schwann cells in the ventral aspect of the spinal cord where they occur predominantly in the grey matter. (author).

  6. Glial-glial and glial-neuronal interfaces in radiation-induced, glia-depleted spinal cord

    International Nuclear Information System (INIS)

    Gilmore, S.A.; Sims, T.J.

    1997-01-01

    This review summarises some of the major findings derived from studies using the model of a glia-depleted environment developed and characterised in this laboratory. Glial depletion is achieved by exposure of the immature rodent spinal cord to x-radiation which markedly reduces both astrocyte and oligodendrocyte populations and severely impairs myelination. This glia-depleted, hypomylinated state presents a unique opportunity to examine aspects of spinal cord maturation in the absence of a normal glial population. An associated sequela within 2-3 wk following irradiation is the appearance of Schwann cells in the dorsal portion of the spinal cord. Characteristics of these intraspinal Schwann cells, their patterns of myelination or ensheathment, and their interrelations with the few remaining central glia have been examined. A later sequela is the development of Schwann cells in the ventral aspect of the spinal cord where they occur predominantly in the grey matter. (author)

  7. Effect of neurotransmitters and bone marrow cells for neuronal regeneration in iatrogenic spinal cord injury: An experimental study.

    Science.gov (United States)

    John, Ps; Paulose, Cs; Sreekanth, R

    2010-07-01

    Spinal cord trauma is a major health problem with associated physical, social, economic and psychological sequelae. Despite many advances in research and treatment modalities, the pathophysiology of spinal cord injury remains unclear, and morbidity and mortality among these patients remain high. This experimental study investigates the regenerative cell proliferation effects of bone marrow supplemented with neurotransmitters combinations in the regeneration of spinal cord injury Ethical Committee Clearance was obtained for animal study. All animal care and procedures were in accordance with the CPCSEA and National Institute of Health guidelines. Thirty Wistar rats with monoplegia following surgical hemitransection of the spinal cord were used for the study. Half of them were randomly selected as the test group and the rest as the control group. Spinal cord injury model of Wistar rats in the test group were treated by infusing a combination of neurotransmitters and bone marrow at the site of injury using a special polythene tube and reservoir for 21 days. In the control group of rats with monoplegia, normal saline was infused at the site of injury for 21 days. The observations are recorded along with results. The monoplegia in the test group of rats recovered significantly (P value bone marrow cells and neurotransmitters combination. In the control group of rats, there was no recovery. The reward-seeking locomotor test and sensory recovery test confirmed recovery from spinal cord injury in the test group with significance. The neurotransmitters and bone marrow combination was responsible for functional recovery in the test group of rats with experimental spinal cord injury We believe that the combination of neurotransmitters along with bone marrow may be a scope of future research in patients with spinal cord injury.

  8. MicroRNA-9 controls apoptosis of neurons by targeting monocyte chemotactic protein-induced protein 1 expression in rat acute spinal cord injury model.

    Science.gov (United States)

    Xu, Yong; An, Bao-Yan; Xi, Xiao-Bing; Li, Zhong-Wei; Li, Fei-Yue

    2016-03-01

    For the purpose of an early identification of intervention targets for acute spinal cord injury (ASCI), we investigated the changes in expression levels of microRNA-9 (miR-9) and MCPIP1 in rat ASCI model. A total of 108 healthy rats were randomly divided into non-ASCI group (n=18) and five ASCI groups, 6h, 12h, 24h, 3 days and 7 days, representing the experimental time points following ASCI (n=18 per group). Hematoxylin and eosin (HE) staining was used to assess the ASCI damage, and quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH) were employed for the detection of miR-9 and MCPIP1 mRNA expression. HE staining results showed normal neuronal morphology in the non-ASCI group, but spinal cord tissue at 6h after ASCI showed developing neuronal necrosis. Acute inflammatory response was evident at 12h and 24h, with immune cells infiltrating into the gray matter. Vascular permeability increased and the nerve cells in gray-white matter exhibited extensive damage and necrosis at 24h and 7 days after ASCI. MiR-9 expression in ASCI tissue was significantly lower than that in normal spinal cord tissue. Statistical analysis showed a significant decrease in miR-9 expression in all the ASCI groups, compared to the non-ASCI group. Results from real-time PCR analysis revealed that MCPIP1 expression in all the ASCI groups was significantly higher than the non-ASCI group, and MCPIP1 expressions gradually increased with times at 6h-24h after ASCI. ISH revealed the following results after ASCI (1) miR-9 and MCPIP1 mRNA expression mainly distributed in ventral horn motor neurons, (2) miR-9 expression was high at 7 day after ASCI and (3) in the non-ASCI group, MCPIP1 expression was high at 6h, 12h, 24h and 3 days. MCPIP1 is significantly up-regulated after ASCI. The negative relationship between MCPIP1 and miR-9 suggest that MCPIP1 mRNA could be a target of miR-9 during ASCI. Thus, miR-9 is a marker for apoptosis in neurons, and an excellent therapeutic target for

  9. Estrogen receptor-alpha and -beta immunoreactive neurons in the brainstem and spinal cord of male and female mice : Relationships to monoaminergic, cholinergic, and spinal projection systems

    NARCIS (Netherlands)

    VanderHorst, VGJM; Gustafsson, JA; Ulfhake, B

    2005-01-01

    For many populations of estrogen-sensitive neurons it remains unknown how they are associated with central nervous system circuitries that mediate estrogen-induced modulation of behavioral components. With the use of double-labeling immunohistochemistry and tracing techniques, the relationships of

  10. Contributions of intrinsic motor neuron properties to the production of rhythmic motor output in the mammalian spinal cord

    DEFF Research Database (Denmark)

    Kiehn, O; Kjaerulff, O; Tresch, M C

    2000-01-01

    Motor neurons are endowed with intrinsic and conditional membrane properties that may shape the final motor output. In the first half of this paper we present data on the contribution of I(h), a hyperpolarization-activated inward cation current, to phase-transition in motor neurons during rhythmic...... firing. Motor neurons were recorded intracellularly during locomotion induced with a mixture of N-methyl-D-aspartate (NMDA) and serotonin, after pharmacological blockade of I(h). I(h) was then replaced by using dynamic clamp, a computer program that allows artificial conductances to be inserted into real...... neurons. I(h) was simulated with biophysical parameters determined in voltage clamp experiments. The data showed that electronic replacement of the native I(h) caused a depolarization of the average membrane potential, a phase-advance of the locomotor drive potential, and increased motor neuron spiking...

  11. Neuronal regeneration in injured rat spinal cord after human dental pulp derived neural crest stem cell transplantation.

    Science.gov (United States)

    Kabatas, S; Demir, C S; Civelek, E; Yilmaz, I; Kircelli, A; Yilmaz, C; Akyuva, Y; Karaoz, E

    2018-01-01

    This study aimed to analyze the effect of human Dental Pulp-Neural Crest Stem Cells (hDP-NCSCs) delivery on lesion site after spinal cord injury (SCI), and to observe the functional recovery after transplantation. Neural Crest Stem Cells (NCSCs) were isolated from human Dental Pulp (hDP). The experimental rat population was divided into four groups (n = 6/24). Their behavioral motility was scored regularly. After 4-weeks, rats were sacrificed, and their spinal cords were examined for Green Fluorescent Protein (GFP) labeled hDP-NCSCs by immunofluorescence (IF) staining. In early post-injury (p.i) period, the ultrastructure of spinal cord tissue was preserved in Group 4. The majority of cells forming the ependymal region around the central canal were found to be hDP-NCSCs. While the grey-and-white-matter around the ependymal region was composed of e.g. GFP cells, with astrocytic-like appearance. The scores showed significant motor recovery in hind limb functions in Group 4. However, no obvious change was observed in other groups. Cells e.g., mesenchymal (Vimentin+) which express GFP+ cells in the gray-and-white-matter around the ependymal region could indicate the potential to self-renewal and plasticity. Thus, transplantation of hDP-NCSCs might be an effective strategy to improve functional recovery following spinal cord trauma (Fig. 10, Ref. 32).

  12. Characterization of upper thoracic spinal neurons receiving noxious cardiac and/or somatic inputs in diabetic rats

    DEFF Research Database (Denmark)

    Ghorbani, Marie Louise M; Qin, Chao; Wu, Mingyuan

    2011-01-01

    The aim of the present study was to examine spinal processing of cardiac and somatic nociceptive input in rats with STZ-induced diabetes. Type 1 diabetes was induced with streptozotocin (50mg/kg) in 14 male Sprague-Dawley rats and citrate buffer was injected in 14 control rats. After 4-11weeks...

  13. Abbreviated exposure to hypoxia is sufficient to induce CNS dysmyelination, modulate spinal motor neuron composition, and impair motor development in neonatal mice.

    Directory of Open Access Journals (Sweden)

    Jens O Watzlawik

    Full Text Available Neonatal white matter injury (nWMI is an increasingly common cause of cerebral palsy that results predominantly from hypoxic injury to progenitor cells including those of the oligodendrocyte lineage. Existing mouse models of nWMI utilize prolonged periods of hypoxia during the neonatal period, require complex cross-fostering and exhibit poor growth and high mortality rates. Abnormal CNS myelin composition serves as the major explanation for persistent neuro-motor deficits. Here we developed a simplified model of nWMI with low mortality rates and improved growth without cross-fostering. Neonatal mice are exposed to low oxygen from postnatal day (P 3 to P7, which roughly corresponds to the period of human brain development between gestational weeks 32 and 36. CNS hypomyelination is detectable for 2-3 weeks post injury and strongly correlates with levels of body and brain weight loss. Immediately following hypoxia treatment, cell death was evident in multiple brain regions, most notably in superficial and deep cortical layers as well as the subventricular zone progenitor compartment. PDGFαR, Nkx2.2, and Olig2 positive oligodendrocyte progenitor cell were significantly reduced until postnatal day 27. In addition to CNS dysmyelination we identified a novel pathological marker for adult hypoxic animals that strongly correlates with life-long neuro-motor deficits. Mice reared under hypoxia reveal an abnormal spinal neuron composition with increased small and medium diameter axons and decreased large diameter axons in thoracic lateral and anterior funiculi. Differences were particularly pronounced in white matter motor tracts left and right of the anterior median fissure. Our findings suggest that 4 days of exposure to hypoxia are sufficient to induce experimental nWMI in CD1 mice, thus providing a model to test new therapeutics. Pathological hallmarks of this model include early cell death, decreased OPCs and hypomyelination in early postnatal life

  14. Light and electron microscopy of contacts between primary afferent fibres and neurones with axons ascending the dorsal columns of the feline spinal cord.

    Science.gov (United States)

    Maxwell, D J; Koerber, H R; Bannatyne, B A

    1985-10-01

    In addition to primary afferent fibres, the dorsal columns of the cat spinal cord contain ascending second-order axons which project to the dorsal column nuclei. The aim of the present study was to obtain morphological evidence that certain primary afferent axons form monosynaptic contacts with cells of origin of this postsynaptic dorsal column pathway. In ten adult cats, neurones with axons ascending the dorsal columns were retrogradely labelled with horseradish peroxidase using a pellet implantation method in the thoracic dorsal columns. In the lumbosacral regions of the same animals, primary afferent fibres were labelled intra-axonally with ionophoretic application of horseradish peroxidase. Tissue containing labelled axons was prepared for light and combined light and electron microscopy. Ultrastructural examination demonstrated that slowly adapting (Type I), hair follicle, Pacinian corpuscle and group Ia muscle spindle afferents formed monosynaptic contacts with labelled cells and light microscopical analysis suggested that they also received monosynaptic input from rapidly adapting (Krause) afferents. This evidence suggests that sensory information from large-diameter cutaneous and muscle spindle afferent fibres is conveyed disynaptically via the postsynaptic dorsal column pathway to the dorsal column nuclei. Some of the input to this pathway is probably modified in the spinal cord as the majority of primary afferent boutons forming monosynaptic contacts were postsynaptic to other axon terminals. The postsynaptic dorsal column system appears to constitute a major somatosensory pathway in the cat.

  15. TRPV1 receptors contribute to mediate paclitaxel-induced c-Fos expression in spinal cord dorsal horn neurons

    Czech Academy of Sciences Publication Activity Database

    Kalynovska, Nataliia; Adámek, Pavel; Paleček, Jiří

    2017-01-01

    Roč. 66, č. 3 (2017), s. 549-532 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GA15-11138S; GA MŠk(CZ) LH15279; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : c-Fos * paclitaxel * TRPV1 * neuropathy * spinal cord Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology Impact factor: 1.461, year: 2016

  16. Neurotoxicity of cerebro-spinal fluid from patients with Parkinson's disease on mesencephalic primary cultures as an in vitro model of dopaminergic neurons.

    Science.gov (United States)

    Kong, Ping; Zhang, Ben-Shu; Lei, Ping; Kong, Xiao-Dong; Zhang, Shi-Shuang; Li, Dai; Zhang, Yun

    2015-08-01

    Parkinson's disease is a degenerative disorder of the central nervous system. In spite of extensive research, neither the cause nor the mechanisms have been firmly established thus far. One assumption is that certain toxic substances may exist in the cerebro-spinal fluid (CSF) of Parkinson's disease patients. To confirm the neurotoxicity of CSF and study the potential correlation between neurotoxicity and the severity of Parkinson's disease, CSF was added to cultured cells. By observation of cell morphology, changes in the levels of lactate dehydrogenase, the ratio of tyrosine hydroxylase-positive cells, and the expression of tyrosine hydroxylase mRNA and protein, the differences between the two groups were shown. The created in vitro model of dopaminergic neurons using primary culture of mouse embryonic mesencephalic tissue is suitable for the study of neurotoxicity. The observations of the present study indicated that CSF from Parkinson's disease patients contains factors that can cause specific injury to cultured dopaminergic neurons. However, no obvious correlation was found between the neurotoxicity of CSF and the severity of Parkinson's disease.

  17. Neurons other than motor neurons in motor neuron disease.

    Science.gov (United States)

    Ruffoli, Riccardo; Biagioni, Francesca; Busceti, Carla L; Gaglione, Anderson; Ryskalin, Larisa; Gambardella, Stefano; Frati, Alessandro; Fornai, Francesco

    2017-11-01

    Amyotrophic lateral sclerosis (ALS) is typically defined by a loss of motor neurons in the central nervous system. Accordingly, morphological analysis for decades considered motor neurons (in the cortex, brainstem and spinal cord) as the neuronal population selectively involved in ALS. Similarly, this was considered the pathological marker to score disease severity ex vivo both in patients and experimental models. However, the concept of non-autonomous motor neuron death was used recently to indicate the need for additional cell types to produce motor neuron death in ALS. This means that motor neuron loss occurs only when they are connected with other cell types. This concept originally emphasized the need for resident glia as well as non-resident inflammatory cells. Nowadays, the additional role of neurons other than motor neurons emerged in the scenario to induce non-autonomous motor neuron death. In fact, in ALS neurons diverse from motor neurons are involved. These cells play multiple roles in ALS: (i) they participate in the chain of events to produce motor neuron loss; (ii) they may even degenerate more than and before motor neurons. In the present manuscript evidence about multi-neuronal involvement in ALS patients and experimental models is discussed. Specific sub-classes of neurons in the whole spinal cord are reported either to degenerate or to trigger neuronal degeneration, thus portraying ALS as a whole spinal cord disorder rather than a disease affecting motor neurons solely. This is associated with a novel concept in motor neuron disease which recruits abnormal mechanisms of cell to cell communication.

  18. Human induced pluripotent stem cell (hiPSC)-derived neurons respond to convulsant drugs when co-cultured with hiPSC-derived astrocytes.

    Science.gov (United States)

    Ishii, Misawa Niki; Yamamoto, Koji; Shoji, Masanobu; Asami, Asano; Kawamata, Yuji

    2017-08-15

    Accurate risk assessment for drug-induced seizure is expected to be performed before entering clinical studies because of its severity and fatal damage to drug development. Induced pluripotent stem cell (iPSC) technology has allowed the use of human neurons and glial cells in toxicology studies. Recently, several studies showed the advantage of co-culture system of human iPSC (hiPSC)-derived neurons with rodent/human primary astrocytes regarding neuronal functions. However, the application of hiPSC-derived neurons for seizure risk assessment has not yet been fully addressed, and not at all when co-cultured with hiPSC-derived astrocytes. Here, we characterized hiPSC-derived neurons co-cultured with hiPSC-derived astrocytes to discuss how hiPSC-derived neurons are useful to assess seizure risk of drugs. First, we detected the frequency of spikes and synchronized bursts hiPSC-derived neurons when co-cultured with hiPSC-derived astrocytes for 8 weeks. This synchronized burst was suppressed by the treatment with 6-cyano-7-nitroquinoxaline-2,3-dione, α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor antagonist, and D-(-)-2-amino-5-phosphonopentanoic acid, an N-Methyl-d-aspartate (NMDA) receptor antagonist. These data suggested that co-cultured hiPSC-derived neurons formed synaptic connections mediated by AMPA and NMDA receptors. We also demonstrated that co-cultured hiPSC-derived neurons showed epileptiform activity upon treatment with gabazine or kaliotoxin. Finally, we performed single-cell transcriptome analysis in hiPSC-derived neurons and found that hiPSC-derived astrocytes activated the pathways involved in the activities of AMPA and NMDA receptor functions, neuronal polarity, and axon guidance in hiPSC-derived neurons. These data suggested that hiPSC-derived astrocytes promoted the development of action potential, synaptic functions, and neuronal networks in hiPSC-derived neurons, and then these functional alterations result in the epileptiform

  19. Deletion of ENTPD3 does not impair nucleotide hydrolysis in primary somatosensory neurons or spinal cord [v1; ref status: indexed, http://f1000r.es/3rm

    Directory of Open Access Journals (Sweden)

    Eric McCoy

    2014-07-01

    Full Text Available Ectonucleotidases are membrane-bound or secreted proteins that hydrolyze extracellular nucleotides.  Recently, we identified three ectonucleotidases that hydrolyze extracellular adenosine 5’-monophosphate (AMP to adenosine in primary somatosensory neurons.  Currently, it is unclear which ectonucleotidases hydrolyze ATP and ADP in these neurons.  Ectonucleoside triphosphate diphosphohydrolases (ENTPDs comprise a class of enzymes that dephosphorylate extracellular ATP and ADP.  Here, we found that ENTPD3 (also known as NTPDase3 or CD39L3 was located in nociceptive and non-nociceptive neurons of the dorsal root ganglion (DRG, in the dorsal horn of the spinal cord, and in free nerve endings in the skin.  To determine if ENTPD3 contributes directly to ATP and ADP hydrolysis in these tissues, we generated and characterized an Entpd3 knockout mouse.  This mouse lacks ENTPD3 protein in all tissues examined, including the DRG, spinal cord, skin, and bladder.  However, DRG and spinal cord tissues from Entpd3-/- mice showed no reduction in histochemical staining when ATP, ADP, AMP, or UTP were used as substrates.  Additionally, using fast-scan cyclic voltammetry (FSCV, adenosine production was not impaired in the dorsal spinal cord of Entpd3-/- mice when the substrate ADP was applied.  Further, Entpd3-/- mice did not differ in nociceptive behaviors when compared to wild-type mice, although Entpd3-/- mice showed a modest reduction in β-alanine-mediated itch.  Taken together, our data indicate that deletion of Entpd3 does not impair ATP or ADP hydrolysis in primary somatosensory neurons or in dorsal spinal cord.  Moreover, our data suggest there could be multiple ectonucleotidases that act redundantly to hydrolyze nucleotides in these regions of the nervous system.

  20. Deletion of ENTPD3 does not impair nucleotide hydrolysis in primary somatosensory neurons or spinal cord [v2; ref status: indexed, http://f1000r.es/4dl

    Directory of Open Access Journals (Sweden)

    Eric McCoy

    2014-09-01

    Full Text Available Ectonucleotidases are membrane-bound or secreted proteins that hydrolyze extracellular nucleotides.  Recently, we identified three ectonucleotidases that hydrolyze extracellular adenosine 5’-monophosphate (AMP to adenosine in primary somatosensory neurons.  Currently, it is unclear which ectonucleotidases hydrolyze ATP and ADP in these neurons.  Ectonucleoside triphosphate diphosphohydrolases (ENTPDs comprise a class of enzymes that dephosphorylate extracellular ATP and ADP.  Here, we found that ENTPD3 (also known as NTPDase3 or CD39L3 was located in nociceptive and non-nociceptive neurons of the dorsal root ganglion (DRG, in the dorsal horn of the spinal cord, and in free nerve endings in the skin.  To determine if ENTPD3 contributes directly to ATP and ADP hydrolysis in these tissues, we generated and characterized an Entpd3 knockout mouse.  This mouse lacks ENTPD3 protein in all tissues examined, including the DRG, spinal cord, skin, and bladder.  However, DRG and spinal cord tissues from Entpd3-/- mice showed no reduction in histochemical staining when ATP, ADP, AMP, or UTP were used as substrates.  Additionally, using fast-scan cyclic voltammetry (FSCV, adenosine production was not impaired in the dorsal spinal cord of Entpd3-/- mice when the substrate ADP was applied.  Further, Entpd3-/- mice did not differ in nociceptive behaviors when compared to wild-type mice, although Entpd3-/- mice showed a modest reduction in β-alanine-mediated itch.  Taken together, our data indicate that deletion of Entpd3 does not impair ATP or ADP hydrolysis in primary somatosensory neurons or in dorsal spinal cord.  Moreover, our data suggest there could be multiple ectonucleotidases that act redundantly to hydrolyze nucleotides in these regions of the nervous system.

  1. Cytokine mechanisms of central sensitization: distinct and overlapping role of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha in regulating synaptic and neuronal activity in the superficial spinal cord.

    Science.gov (United States)

    Kawasaki, Yasuhiko; Zhang, Ling; Cheng, Jen-Kun; Ji, Ru-Rong

    2008-05-14

    Central sensitization, increased sensitivity in spinal cord dorsal horn neurons after injuries, plays an essential role in the induction and maintenance of chronic pain. However, synaptic mechanisms underlying central sensitization are incompletely known. Growing evidence suggests that proinflammatory cytokines (PICs), such as interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNFalpha), are induced in the spinal cord under various injury conditions and contribute to pain hypersensitivity. Using patch-clamp recordings in lamina II neurons of isolated spinal cord slices, we compared the effects of IL-1beta, IL-6, and TNFalpha on excitatory and inhibitory synaptic transmission. Whereas TNFalpha enhanced the frequency of spontaneous EPSCs (sEPSCs), IL-6 reduced the frequency of spontaneous IPSCs (sIPSCs). Notably, IL-1beta both enhanced the frequency and amplitude of sEPSCs and reduced the frequency and amplitude of sIPSCs. Consistently, TNFalpha and IL-1beta enhanced AMPA- or NMDA-induced currents, and IL-1beta and IL-6 suppressed GABA- and glycine-induced currents. Furthermore, all the PICs increased cAMP response element-binding protein (CREB) phosphorylation in superficial dorsal horn neurons and produced heat hyperalgesia after spinal injection. Surprisingly, soluble IL-6 receptor (sIL-6R) produced initial decrease of sEPSCs, followed by increase of sEPSCs and CREB phosphorylation. Spinal injection of sIL-6R also induced heat hyperalgesia that was potentiated by coadministration with IL-6. Together, our data have demonstrated that PICs induce central sensitization and hyperalgesia via distinct and overlapping synaptic mechanisms in superficial dorsal horn neurons either by increasing excitatory synaptic transmission or by decreasing inhibitory synaptic transmission. PICs may further induce long-term synaptic plasticity through CREB-mediated gene transcription. Blockade of PIC signaling could be an effective way to suppress

  2. Brain-Derived Neurotrophic Factor Facilitates Functional Recovery from ALS-Cerebral Spinal Fluid-Induced Neurodegenerative Changes in the NSC-34 Motor Neuron Cell Line.

    Science.gov (United States)

    Shruthi, Shanmukha; Sumitha, R; Varghese, Anu Mary; Ashok, S; Chandrasekhar Sagar, B K; Sathyaprabha, T N; Nalini, A; Kramer, Boris W; Raju, Trichur R; Vijayalakshmi, K; Alladi, Phalguni Anand

    2017-01-01

    The survival of motor neurons is dependent upon neurotrophic factors both during childhood and adolescence and during adult life. In disease conditions, such as in patients with amyotrophic lateral sclerosis (ALS), the mRNA levels of trophic factors like brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), fibroblast growth factor-2 (FGF-2), and vascular endothelial growth factor are downregulated. This was replicated in our in vivo experimental system following the injection of cerebral spinal fluid (CSF) of sporadic ALS (ALS-CSF) patients. To evaluate the protective role of BDNF in a model of sporadic ALS patients. The expressions of endogenous BDNF, its receptor TrkB, the enzyme choline acetyl transferase (ChAT), and phosphorylated neurofilaments were studied in NSC-34 cells. The calcium-buffering and proapoptotic effects were assessed by calbindin-D28K and caspase-3 expression, respectively. ALS-CSF considerably depleted the endogenous BDNF protein, while its effect on IGF-1 and FGF-2 was inconsequential; this indirectly indicates a key role for BDNF in supporting motor neuronal survival. The exogenous supplementation of BDNF reversed autocrine expression; however, it may not be completely receptor mediated, as the TrkB levels were not restored. BDNF completely revived ChAT expression. It may inhibit apoptosis by restoring Ca2+ homeostasis, since caspase-3 and calbindin-D28K expression was back to normal. The organellar ultrastructural changes were only partially reversed. Our study provides evidence that BDNF supplementation ameliorates most but not all degenerative changes. The incomplete revival at the ultrastructural level signifies the requirement of factors other than BDNF for near-total protection of motor neurons, and, to an extent, it explains why only a partial success is achieved in clinical trials with BDNF in ALS patients. © 2016 S. Karger AG, Basel.

  3. Purines released from astrocytes inhibit excitatory synaptic transmission in the ventral horn of the spinal cord

    DEFF Research Database (Denmark)

    Carlsen, Eva Maria Meier; Perrier, Jean-Francois Marie

    2014-01-01

    . Neurons responded to electrical stimulation by monosynaptic EPSCs (excitatory monosynaptic postsynaptic currents). We used mice expressing the enhanced green fluorescent protein under the promoter of the glial fibrillary acidic protein to identify astrocytes. Chelating calcium with BAPTA in a single...... by different neuromodulators. These substances are usually thought of being released by dedicated neurons. However, in other networks from the central nervous system synaptic transmission is also modulated by transmitters released from astrocytes. The star-shaped glial cell responds to neurotransmitters...... by releasing gliotransmitters, which in turn modulate synaptic transmission. Here we investigated if astrocytes present in the ventral horn of the spinal cord modulate synaptic transmission. We evoked synaptic inputs in ventral horn neurons recorded in a slice preparation from the spinal cord of neonatal mice...

  4. Spinal nociceptive transmission by mechanical stimulation of bone marrow.

    Science.gov (United States)

    Ishida, Takashi; Tanaka, Satoshi; Sekiguchi, Takemi; Sugiyama, Daisuke; Kawamata, Mikito

    2016-01-01

    Since bone marrow receives innervation from A-delta and C-fibers and since an increase in intramedullary pressure in bone marrow may induce acute pain in orthopedic patients during surgery and chronic pain in patients with bone marrow edema, skeletal pain may partly originate from bone marrow. Intraosseous lesions, such as osteomyelitis and bone cancer, are also known to produce cutaneous hypersensitivity, which might be referred pain from bone. However, little is known about pain perception in bone marrow and referred pain induced by bone disease. Thus, we carried out an in vivo electrophysiological study and behavioral study to determine whether increased intraosseous pressure of the femur induces acute pain and whether increased intraosseous pressure induces referred pain in the corresponding receptive fields of the skin. Intraosseous balloon inflation caused spontaneous pain-related behavior and mechanical hyperalgesia and allodynia in the lumbosacral region. Single neuronal activities of spinal dorsal horn neurons were extracellularly isolated, and then evoked responses to non-noxious and noxious cutaneous stimuli and intraosseous balloon inflation were recorded. Ninety-four spinal dorsal horn neurons, which had somatic receptive fields at the lower back and thigh, were obtained. Sixty-two percent of the wide-dynamic-range neurons (24/39) and 86% of the high-threshold neurons (12/14) responded to intraosseous balloon inflation, while none of the low-threshold neurons (0/41) responded to intraosseous balloon inflation. Spinally administered morphine (1 µg) abolished balloon inflation-induced spontaneous pain-related behavior and mechanical hyperalgesia in awake rats and also suppressed evoked activities of wide-dynamic-range neurons to noxious cutaneous stimulation and intraosseous balloon inflation. The results suggest that mechanical stimulation to bone marrow produces nociception, concomitantly producing its referred pain in the corresponding skin fields

  5. Electrophysiological evidence of increased glycine receptor-mediated phasic and tonic inhibition by blockade of glycine transporters in spinal superficial dorsal horn neurons of adult mice

    Directory of Open Access Journals (Sweden)

    Misa Oyama

    2017-03-01

    Full Text Available To understand the synaptic and/or extrasynaptic mechanisms underlying pain relief by blockade of glycine transporter subtypes GlyT1 and GlyT2, whole-cell recordings were made from dorsal horn neurons in spinal slices from adult mice, and the effects of NFPS and ALX-1393, selective GlyT1 and GlyT2 inhibitors, respectively, on phasic evoked or miniature glycinergic inhibitory postsynaptic currents (eIPSCs or mIPSCs were examined. NFPS and ALX-1393 prolonged the decay phase of eIPSCs without affecting their amplitude. In the presence of tetrodotoxin to record mIPSCs, NFPS and ALX-1393 induced a tonic inward current that was reversed by strychnine. Although NFPS had no statistically significant influences on mIPSCs, ALX-1393 significantly increased their frequency. We then further explored the role of GlyTs in the maintenance of glycinergic IPSCs. To facilitate vesicular release of glycine, repetitive high-frequency stimulation (HFS was applied at 10 Hz for 3 min during continuous recordings of eIPSCs at 0.1 Hz. Prominent suppression of eIPSCs was evident after HFS in the presence of ALX-1393, but not NFPS. Thus, it appears that phasic and tonic inhibition may contribute to the analgesic effects of GlyT inhibitors. However, reduced glycinergic inhibition due to impaired vesicular refilling could hamper the analgesic efficacy of GlyT2 inhibitors.

  6. Fine T cell receptor repertoire analysis of spinal cord T cells responding to the major and minor epitopes of myelin basic protein during rat autoimmune encephalomyelitis.

    Science.gov (United States)

    Matsumoto, Y; Jee, Y; Sugisaki, M; Kim, G; Tanuma, N

    2000-01-01

    Experimental autoimmune encephalomyelitis is a disease induced by neuroantigen-reactive T cells bearing particular types of T cell receptor (TCR). Although the nature of TCRs of encephalitogenic T cells has been partially delineated using encephalitogenic T cell clones established in vitro, the entire TCR repertoire formed in situ after immunization with neuroantigen remains unclear. In the present study, we immunized Lewis rats with myelin basic protein (MBP) and its fragment peptides and determined the TCR repertoire of spinal cord T cells formed after the immunization by CDR3 spectra-typing. It was revealed that the oligoclonal expansion of Vbeta2, Vbeta8.2, and Vbeta17 spectratypes was detectable after immunization with guinea pig MBP and its immunodominant epitope, the 68-88 sequence, whereas immunization with a peptide containing a minor epitope induced Vbeta10 expansion. Immunization with rat MBP induced much broader TCR Vbeta expansion (all of the above Vbetas plus Vbeta3). These findings suggest that TCRs activated by immunization with guinea pig MBP used as heteroclitic immunogen recognize autoantigen, rat MBP. Furthermore, the strategy used in this study gives insight into the pathogenesis of autoimmune disease and provides useful information for designing TCR-based immunotherapy.

  7. Distinct recruitment of the hippocampal, thalamic, and amygdalar neurons projecting to the prelimbic cortex in male and female rats during context-mediated renewal of responding to food cues.

    Science.gov (United States)

    Anderson, Lauren C; Petrovich, Gorica D

    2018-02-26

    Persistent responding to food cues may underlie the difficulty to resist palatable foods and to maintain healthy eating habits. Renewal of responding after extinction is a model of persistent food seeking that can be used to study the underlying neural mechanisms. In context-mediated renewal, a return to the context in which the initial cue-food learning occurred induces robust responding to the cues that were extinguished elsewhere. Previous work found sex differences in context-mediated renewal and in the recruitment of the ventromedial prefrontal cortex (vmPFC) during that behavior. Males exhibited renewal of responding to food cues and had higher Fos induction in the prelimbic area (PL) of the vmPFC, while females failed to exhibit renewal of responding and had lower Fos induction in the PL. The main aim of the current study was to determine key components of the PL circuitry mediating renewal. The focus was on inputs from three areas important in appetitive associative learning and contextual processing: the amygdala, ventral hippocampal formation, and the paraventricular nucleus of the thalamus. The goal was to determine whether neurons from these areas that send direct projections to the PL (identified with a retrograde tracer) are selectively activated (Fos induction) during renewal and whether they are differently recruited in males and females. The Fos induction patterns demonstrated that the PL-projecting neurons in each of these areas were recruited in a sex-specific way that corresponded to the behavioral differences between males and females. These pathways were selectively activated in the male experimental group-the only group that showed renewal behavior. The findings suggest the pathways from the ventral hippocampal formation, paraventricular nucleus of the thalamus, and basolateral amygdala to the PL mediate renewal in males. The lack of recruitment in females suggests that under activation of these pathways may underlie their lack of renewal

  8. Young Human Cholinergic Neurons Respond to Physiological Regulators and Improve Cognitive Symptoms in an Animal Model of Alzheimer’s Disease

    Science.gov (United States)

    Morelli, Annamaria; Sarchielli, Erica; Guarnieri, Giulia; Coppi, Elisabetta; Pantano, Daniela; Comeglio, Paolo; Nardiello, Pamela; Pugliese, Anna M.; Ballerini, Lara; Matucci, Rosanna; Ambrosini, Stefano; Castronovo, Giuseppe; Valente, Rosa; Mazzanti, Benedetta; Bucciantini, Sandra; Maggi, Mario; Casamenti, Fiorella; Gallina, Pasquale; Vannelli, Gabriella B.

    2017-01-01

    The degeneration of cholinergic neurons of the nucleus basalis of Meynert (NBM) in the basal forebrain (BF) is associated to the cognitive decline of Alzheimer’s disease (AD) patients. To date no resolutive therapies exist. Cell-based replacement therapy is a strategy currently under consideration, although the mechanisms underlying the generation of stem cell-derived NBM cholinergic neurons able of functional integration remain to be clarified. Since fetal brain is an optimal source of neuronal cells committed towards a specific phenotype, this study is aimed at isolating cholinergic neurons from the human fetal NBM (hfNBMs) in order to study their phenotypic, maturational and functional properties. Extensive characterization confirmed the cholinergic identity of hfNBMs, including positivity for specific markers (such as choline acetyltransferase) and acetylcholine (Ach) release. Electrophysiological measurements provided the functional validation of hfNBM cells, which exhibited the activation of peculiar sodium (INa) and potassium (IK) currents, as well as the presence of functional cholinergic receptors. Accordingly, hfNBMs express both nicotinic and muscarinic receptors, which were activated by Ach. The hfNBMs cholinergic phenotype was regulated by the nerve growth factor (NGF), through the activation of the high-affinity NGF receptor TrkA, as well as by 17-β-estradiol through a peculiar recruitment of its own receptors. When intravenously administered in NBM-lesioned rats, hfNBMs determined a significant improvement in memory functions. Histological examination of brain sections showed that hfNBMs (labeled with PKH26 fluorescent dye prior to administration) reached the damaged brain areas. The study provides a useful model to study the ontogenetic mechanisms regulating the development and maintenance of the human brain cholinergic system and to assess new lines of research, including disease modeling, drug discovery and cell-based therapy for AD. PMID

  9. Young Human Cholinergic Neurons Respond to Physiological Regulators and Improve Cognitive Symptoms in an Animal Model of Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Annamaria Morelli

    2017-10-01

    Full Text Available The degeneration of cholinergic neurons of the nucleus basalis of Meynert (NBM in the basal forebrain (BF is associated to the cognitive decline of Alzheimer’s disease (AD patients. To date no resolutive therapies exist. Cell-based replacement therapy is a strategy currently under consideration, although the mechanisms underlying the generation of stem cell-derived NBM cholinergic neurons able of functional integration remain to be clarified. Since fetal brain is an optimal source of neuronal cells committed towards a specific phenotype, this study is aimed at isolating cholinergic neurons from the human fetal NBM (hfNBMs in order to study their phenotypic, maturational and functional properties. Extensive characterization confirmed the cholinergic identity of hfNBMs, including positivity for specific markers (such as choline acetyltransferase and acetylcholine (Ach release. Electrophysiological measurements provided the functional validation of hfNBM cells, which exhibited the activation of peculiar sodium (INa and potassium (IK currents, as well as the presence of functional cholinergic receptors. Accordingly, hfNBMs express both nicotinic and muscarinic receptors, which were activated by Ach. The hfNBMs cholinergic phenotype was regulated by the nerve growth factor (NGF, through the activation of the high-affinity NGF receptor TrkA, as well as by 17-β-estradiol through a peculiar recruitment of its own receptors. When intravenously administered in NBM-lesioned rats, hfNBMs determined a significant improvement in memory functions. Histological examination of brain sections showed that hfNBMs (labeled with PKH26 fluorescent dye prior to administration reached the damaged brain areas. The study provides a useful model to study the ontogenetic mechanisms regulating the development and maintenance of the human brain cholinergic system and to assess new lines of research, including disease modeling, drug discovery and cell-based therapy for AD.

  10. Broadband Prosthetic Interfaces: Combining Nerve Transfers and Implantable Multichannel EMG Technology to Decode Spinal Motor Neuron Activity

    Directory of Open Access Journals (Sweden)

    Konstantin D. Bergmeister

    2017-07-01

    Full Text Available Modern robotic hands/upper limbs may replace multiple degrees of freedom of extremity function. However, their intuitive use requires a high number of control signals, which current man-machine interfaces do not provide. Here, we discuss a broadband control interface that combines targeted muscle reinnervation, implantable multichannel electromyographic sensors, and advanced decoding to address the increasing capabilities of modern robotic limbs. With targeted muscle reinnervation, nerves that have lost their targets due to an amputation are surgically transferred to residual stump muscles to increase the number of intuitive prosthetic control signals. This surgery re-establishes a nerve-muscle connection that is used for sensing nerve activity with myoelectric interfaces. Moreover, the nerve transfer determines neurophysiological effects, such as muscular hyper-reinnervation and cortical reafferentation that can be exploited by the myoelectric interface. Modern implantable multichannel EMG sensors provide signals from which it is possible to disentangle the behavior of single motor neurons. Recent studies have shown that the neural drive to muscles can be decoded from these signals and thereby the user's intention can be reliably estimated. By combining these concepts in chronic implants and embedded electronics, we believe that it is in principle possible to establish a broadband man-machine interface, with specific applications in prosthesis control. This perspective illustrates this concept, based on combining advanced surgical techniques with recording hardware and processing algorithms. Here we describe the scientific evidence for this concept, current state of investigations, challenges, and alternative approaches to improve current prosthetic interfaces.

  11. Academics respond

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2015-01-01

    Contribution to the article "Academics respond: Brexit would weaken UK university research and funding", Guardian Witness, The Guardian, UK......Contribution to the article "Academics respond: Brexit would weaken UK university research and funding", Guardian Witness, The Guardian, UK...

  12. Spinal cord mechanisms of pain.

    Science.gov (United States)

    D'Mello, R; Dickenson, A H

    2008-07-01

    The spinal cord is the first relay site in the transmission of nociceptive information from the periphery to the brain. Sensory signals are transmitted from the periphery by primary afferent fibres into the dorsal horn of the spinal cord, where these afferents synapse with intrinsic spinal dorsal horn neurones. Spinal projection neurones then convey this information to higher centres in the brain, where non-noxious and noxious signals can be perceived. During nociceptive transmission, the output of the spinal cord is dependent on various spinal mechanisms which can either increase or decrease the activity of dorsal horn neurones. Such mechanisms include local excitatory and inhibitory interneurones, N-methyl-D-aspartate receptor activation, and descending influences from the brainstem, which can be both inhibitory and excitatory in nature. After nerve injury or conditions of inflammation, shifts can occur in these excitatory and inhibitory mechanisms which modulate spinal excitability, often resulting in the heightened response of dorsal neurones to incoming afferent signals, and increased output to the brain, a phenomenon known as central sensitization. In this review, we consider the ways in which spinal cord activity may be altered in chronic pain states. In addition, we discuss the spinal mechanisms which are targeted by current analgesics used in the management of chronic pain.

  13. Reduction of anion reversal potential subverts the inhibitory control of firing rate in spinal lamina I neurons: towards a biophysical basis for neuropathic pain

    Directory of Open Access Journals (Sweden)

    Sejnowski Terrence J

    2006-10-01

    Full Text Available Abstract Background Reduction of the transmembrane chloride gradient in spinal lamina I neurons contributes to the cellular hyperexcitability producing allodynia and hyperalgesia after peripheral nerve injury. The resultant decrease in anion reversal potential (i.e. shift in Eanion to less negative potentials reduces glycine/GABAA receptor-mediated hyperpolarization, but the large increase in membrane conductance caused by inhibitory input can nonetheless shunt concurrent excitatory input. Without knowing the relative contribution of hyperpolarization and shunting to inhibition's modulation of firing rate, it is difficult to predict how much net disinhibition results from reduction of Eanion. We therefore used a biophysically accurate lamina I neuron model to investigate quantitatively how changes in Eanion affect firing rate modulation. Results Simulations reveal that even a small reduction of Eanion compromises inhibitory control of firing rate because reduction of Eanion not only decreases glycine/GABAA receptor-mediated hyperpolarization, but can also indirectly compromise the capacity of shunting to reduce spiking. The latter effect occurs because shunting-mediated modulation of firing rate depends on a competition between two biophysical phenomena: shunting reduces depolarization, which translates into reduced spiking, but shunting also shortens the membrane time constant, which translates into faster membrane charging and increased spiking; the latter effect predominates when average depolarization is suprathreshold. Disinhibition therefore occurs as both hyperpolarization- and shunting-mediated modulation of firing rate are subverted by reduction of Eanion. Small reductions may be compensated for by increased glycine/GABAA receptor-mediated input, but the system decompensates (i.e. compensation fails as reduction of Eanion exceeds a critical value. Hyperexcitability necessarily develops once disinhibition becomes incompensable

  14. Chronic at-level thermal hyperalgesia following rat cervical contusion spinal cord injury is accompanied by neuronal and astrocyte activation and loss of the astrocyte glutamate transporter, GLT1, in superficial dorsal horn.

    Science.gov (United States)

    Putatunda, Rajarshi; Hala, Tamara J; Chin, Jeannie; Lepore, Angelo C

    2014-09-18

    Neuropathic pain is a form of pathological nociception that occurs in a significant portion of traumatic spinal cord injury (SCI) patients, resulting in debilitating and often long-term physical and psychological burdens. While many peripheral and central mechanisms have been implicated in neuropathic pain, central sensitization of dorsal horn spinothalamic tract (STT) neurons is a major underlying substrate. Furthermore, dysregulation of extracellular glutamate homeostasis and chronic astrocyte activation play important underlying roles in persistent hyperexcitability of these superficial dorsal horn neurons. To date, central sensitization and astrocyte changes have not been characterized in cervical SCI-induced neuropathic pain models, despite the fact that a major portion of SCI patients suffer contusion trauma to cervical spinal cord. In this study, we have characterized 2 rat models of unilateral cervical contusion SCI that behaviorally result in chronic persistence of thermal hyperalgesia in the ipsilateral forepaw. In addition, we find that STT neurons are chronically activated in both models when compared to laminectomy-only uninjured rats. Finally, persistent astrocyte activation and significantly reduced expression of the major CNS glutamate transporter, GLT1, in superficial dorsal horn astrocytes are associated with both excitability changes in STT neurons and the neuropathic pain behavioral phenotype. In conclusion, we have characterized clinically-relevant rodent models of cervical contusion-induced neuropathic pain that result in chronic activation of both STT neurons and astrocytes, as well as compromise in astrocyte glutamate transporter expression. These models can be used as important tools to further study mechanisms underlying neuropathic pain post-SCI and to test potential therapeutic interventions. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Segmental and laminar organization of the spinal neurons projecting to the periaqueductal gray (PAG) in the cat suggests the existence of at least five separate clusters of spino-PAG neurons

    NARCIS (Netherlands)

    Mouton, Leonora J.; Holstege, Gert

    2000-01-01

    The present retrograde tracing study in the cat describes the spinal cord projections to the periaqueductal gray (PAC), taking into account different regions of the PAG and all spinal segments. Results show that injecting different parts of the PAC leads to different laminar and segmental

  16. Cross-sensitization to morphine in cocaine-sensitized rats: behavioral assessments correlate with enhanced responding of ventral pallidal neurons to morphine and glutamate, with diminished effects of GABA.

    Science.gov (United States)

    McDaid, J; Dallimore, J E; Mackie, A R; Mickiewicz, A L; Napier, T C

    2005-06-01

    Common neurobiological substrates contribute to the progressively increased behavioral effects (i.e., sensitization) that occur with repeated intermittent treatments of cocaine and morphine. Consequently, repeated exposure to cocaine can augment responding to morphine (termed cross-sensitization). Drug-induced sensitization in rats may model aspects of the dysfunction in motivation that are imposed by addiction. The ventral pallidum (VP) is involved in motivated behaviors and its function is altered by acute administration of cocaine and morphine, but the effects of repeated drug exposure remain unknown. Targeting this paucity, the present study evaluated electrophysiological changes in the VP of rats exposed to five once-daily cocaine treatments (15 mg/kg i.p.). This regimen also induced behavioral-sensitization that was expressed 3 days later when the rats received either an acute injection of cocaine (15 mg/kg i.p.) or morphine (10 mg/kg i.p.). VP neurons recorded in vivo 3 days after the repeated cocaine treatment regimen demonstrated increased excitatory responding to microiontophoretic applications of morphine and glutamate. The maximal effect (E(max)) was increased without altering potency, suggesting a change in the functional efficacy of the respective receptor systems. This did not represent a potentiation in transmission in general, for the effects of GABA were diminished. The results provide the first evidence for cellular adaptation in the VP after a sensitizing drug treatment paradigm and reveal that cross-sensitization of drug-induced behaviors temporally correlates with changes in VP neuronal responding. These findings advance an emerging theme that alterations in the VP may contribute to the increased motivation for drug seeking that occurs in drug-withdrawn addicts.

  17. [Mirror neurons].

    Science.gov (United States)

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal. Some of them also respond to the emotional expression of other animals of the same species. These mirror neurons have also been found in humans. They respond to or "reflect" actions of other individuals in the brain and are thought to represent the basis for imitation and empathy and hence the neurobiological substrate for "theory of mind", the potential origin of language and the so-called moral instinct.

  18. Tarsal taste neurons of Helicoverpa assulta (Guenée) respond to sugars and amino acids, suggesting a role in feeding and oviposition.

    Science.gov (United States)

    Zhang, Yun-Feng; Huang, Ling-Qiao; Ge, Feng; Wang, Chen-Zhu

    2011-10-01

    Helicoverpa assulta and Helicoverpa armigera are sibling species with different host-plant ranges. We have previously reported electrophysiological and behavioral responses of H.armigera to sugars and amino acids. Here we describe a parallel study performed on H. assulta and compare the results obtained with the two species. In females, fourteen gustatory chemosensilla, identified on one ventrolateral side of the fifth tarsomere were stimulated with sucrose, glucose, fructose, maltose, myo-inositol, and the twenty common amino acids, using the tip-recording technique. The taste receptor neurons in eight chemosensilla were identified sensitive to the sugars, myo-inositol, Lys, Glu, Arg, Trp, and Ser which all induced proboscis extension reflex (PER) when tarsi were stimulated. There was a positive correlation between electrophysiological activities and PER responses triggered by sucrose. No stimulatory effect on oviposition was observed with sugar or amino acid mixtures. In males, three chemosensilla showed responses to the four sugars, but generally weaker than in females. The major difference of the two species was the variety of amino acids triggering electrophysiological responses. The stimulatory effect of sugars and amino acids on H.assulta was also generally weaker than that on H. armigera. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Induction of Fos protein immunoreactivity by spinal cord contusion

    Directory of Open Access Journals (Sweden)

    E.A. Del-Bel

    2000-05-01

    Full Text Available The objective of the present study was to identify neurons in the central nervous system that respond to spinal contusion injury in the rat by monitoring the expression of the nuclear protein encoded by the c-fos gene, an activity-dependent gene, in spinal cord and brainstem regions. Rats were anesthetized with urethane and the injury was produced by dropping a 5-g weight from 20.0 cm onto the exposed dura at the T10-L1 vertebral level (contusion group. The spinal cord was exposed but not lesioned in anesthetized control animals (laminectomy group; intact animals were also subjected to anesthesia (intact control. Behavioral alterations were analyzed by Tarlov/Bohlman scores, 2 h after the procedures and the animals were then perfused for immunocytochemistry. The patterns of Fos-like immunoreactivity (FLI which were site-specific, reproducible and correlated with spinal laminae that respond predominantly to noxious stimulation or injury: laminae I-II (outer substantia gelatinosa and X and the nucleus of the intermediolateral cell column. At the brain stem level FLI was detected in the reticular formation, area postrema and solitary tract nucleus of lesioned animals. No Fos staining was detected by immunocytochemistry in the intact control group. However, detection of FLI in the group submitted to anesthesia and surgical procedures, although less intense than in the lesion group, indicated that microtraumas may occur which are not detected by the Tarlov/Bohlman scores. There is both a local and remote effect of a distal contusion on the spinal cord of rats, implicating sensory neurons and centers related to autonomic control in the reaction to this kind of injury.

  20. Midodrine improves ejaculation in spinal cord injured men.

    Science.gov (United States)

    Soler, J M; Previnaire, J G; Plante, P; Denys, P; Chartier-Kastler, E

    2007-11-01

    We evaluated the effect of the alpha1-adrenergic agonist midodrine given orally for anejaculation in spinal cord injured men. A total of 185 spinal cord injured patients who reported absent ejaculation during sexual intercourse and who failed to respond to penile vibratory stimulation were treated with midodrine 30 to 120 minutes before a new stimulation. The procedure was repeated weekly, increasing doses by 7.5 mg to a maximum of 30 mg. Cardiovascular effects were monitored throughout the procedure. Antegrade or retrograde ejaculation was achieved in 102 spinal cord injured men (64.6%). A positive response was more frequent in patients with complete lesions (American Spinal Injury Association A) and upper motor neuron lesions above T10. Midodrine induced a significant but moderate increase (maximum 10 mm Hg) in mean arterial pressure in all patients. The highest systolic blood pressure (more than 200 mm Hg) was seen in patients with quadriplegia. No other significant side effect was recorded. The average dose of midodrine required for ejaculation was 18.7 mg. Midodrine is a safe and efficient adjunct to penile vibratory stimulation for anejaculation in spinal cord injured patients.

  1. Cellular Scaling Rules for Primate Spinal Cords

    OpenAIRE

    Burish, Mark J.; Peebles, J. Klint; Baldwin, Mary K.; Tavares, Luciano; Kaas, Jon H.; Herculano-Houzel, Suzana

    2010-01-01

    The spinal cord can be considered a major sensorimotor interface between the body and the brain. How does the spinal cord scale with body and brain mass, and how are its numbers of neurons related to the number of neurons in the brain across species of different body and brain sizes? Here we determine the cellular composition of the spinal cord in eight primate species and find that its number of neurons varies as a linear function of cord length, and accompanies body mass raised to an expone...

  2. Therapeutics development for spinal muscular atrophy

    OpenAIRE

    Sumner, Charlotte J.

    2006-01-01

    Spinal muscular atrophy is an autosomal recessive motor neuron disease that is the leading inherited cause of infant and early childhood mortality. Spinal muscular atrophy is caused by mutation of the telomeric copy of the survival motor neuron gene (SMN1), but all patients retain a centromeric copy of the gene,SMN2. SMN2 produces reduced amounts of full-length SMN mRNA, and spinal muscular atrophy likely results from insufficient levels of SMN protein in motor neurons. The SMN protein plays ...

  3. Genetics of Pediatric-Onset Motor Neuron and Neuromuscular Diseases

    Science.gov (United States)

    2015-08-24

    Spinal Muscular Atrophy; Charcot-Marie-Tooth Disease; Muscular Dystrophy; Spinal Muscular Atrophy With Respiratory Distress 1; Amyotrophic Lateral Sclerosis; Motor Neuron Disease; Neuromuscular Disease; Peroneal Muscular Atrophy; Fragile X Syndrome

  4. Real time large scale in vivo observations reveal intrinsic synchrony, plasticity and growth cone dynamics of midline crossing axons during neuronal wiring of the zebrafish spinal cord.

    Science.gov (United States)

    Andersen, Søren S L

    2017-08-30

    How axons are wired in the vertebrate spinal cord has been studied mostly using fixed samples or looking at individually growing axons. Using light-sheet microscopy, early neural development is here followed in vivo in real time at high resolution along several hundred micrometers of the zebrafish spinal cord. The dynamics and time course of cellular development and axonal wiring of interneurons expressing GFP under control of the dmrt3 promotor are analyzed. Following neurulation, commissural axons are observed crossing the ventral floor plate midline perpendicularly at about 20 microns/h and in a manner dependent on the Robo3 but not the EphA4 receptors. Ipsilateral axons extend concurrently, at three to six times higher growth rates and independently of said receptors. At guidance points, commissural axons are seen to decrease their growth rate and cones increase in size. Commissural filopodia appear on the floor plate to interact with the nascent neural network, and thereby trigger immediate plastic and reversible sinusoidal-shaped bending movements of the neighboring commissural shafts. A 3D reconstruction of the 4 dpf spinal cord demonstrates variable dmrt3 cell body position and dimensions, confirmed by single cell FlowSight analysis, and also a minor second population of commissurals crossing later and more dorsally. The recordings show the strikingly stereotyped spatio-temporal control that governs axonal wiring of the zebrafish spinal cord. The live observations give renewed perspective on the mechanisms of axonal guidance in the spinal cord that provide for a discussion of the current distinction between diffusible long-range versus substrate-bound short-range guidance cues. This article is protected by copyright. All rights reserved. © 2017 Wiley Periodicals, Inc.

  5. Genetic marking and characterization of Tac2-expressing neurons in the central and peripheral nervous system

    Directory of Open Access Journals (Sweden)

    Mar Lynn

    2012-01-01

    Full Text Available Abstract Background The neurocircuits that process somatic sensory information in the dorsal horn of the spinal cord are still poorly understood, with one reason being the lack of Cre lines for genetically marking or manipulating selective subpopulations of dorsal horn neurons. Here we describe Tac2-Cre mice that were generated to express the Cre recombinase gene from the Tac2 locus. Tachykinin 2 (Tac2 encodes a neurotransmitter, neurokinin B (NKB. Results By crossing Tac2-Cre mice with ROSA26-tdTomato reporter mice, we directly visualized Tac2 lineage neurons in the dorsal root ganglia, the dorsal horn of the spinal cord, and many parts of the brain including the olfactory bulb, cerebral cortex, amygdala, hippocampus, habenula, hypothalamus, and cerebellum. This Tac2-Cre allele itself was a null allele for the Tac2 gene. Behavioral analyses showed that Tac2 homozygous null mice responded normally to a series of algogenic (pain-inducing and pruritic (itch-inducing stimuli. Conclusions Tac2-Cre mice are a useful tool to mark specific subsets of neurons in the sensory ganglia, the dorsal spinal cord, and the brain. These mice can also be used for future genetic manipulations to study the functions of Tac2-expressing neurons or the functions of genes expressed in these neurons.

  6. Chimeric Self-assembling Nanofiber Containing Bone Marrow Homing Peptide's Motif Induces Motor Neuron Recovery in Animal Model of Chronic Spinal Cord Injury; an In Vitro and In Vivo Investigation.

    Science.gov (United States)

    Tavakol, Shima; Saber, Reza; Hoveizi, Elham; Aligholi, Hadi; Ai, Jafar; Rezayat, Seyed Mahdi

    2016-07-01

    To date, spinal cord injury (SCI) has remained an incurable disaster. The use of self-assembling peptide nanofiber containing bioactive motifs such as bone marrow homing peptide (BMHP1) as an injectable scaffold in spinal cord regeneration has been suggested. Human endometrial-derived stromal cells (hEnSCs) have been approved by the FDA for clinical application. In this regard, we were interested in investigating the role of BMHP1 in hEnSCs' neural differentiation in vitro and evaluating the supportive effects of this scaffold in rat model of chronic SCI. 1,1-Diphenyl-2-picryl-hydrazyl (DPPH), lactate dehydrogenase (LDH) release, 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay, real-time PCR, and immunocyotochemistry (ICC) were performed as a biocompatibility and neural differentiation evaluations on neuron-like hEnSC-derived cells encapsulated into nanofiber. Nanofiber was implanted into rats and followed by behavioral test, Nissl, luxol fast blue (LFB) staining and immunohistostaining (IHC). Results indicated that cell membrane of neuroblastoma cells were more sensitive than hEnSCs to concentration of proton and cell proliferation decreased with increase of concentration. This effect might be related to oxygen tension and elastic modules of scaffold. -BMHP1 nanofiber induced neural differentiation in hEnSC and decreased GFAP gene and protein as a marker of reactive astrocytes in vitro and in vivo. A reason for this finding might be related to the role of spacer number in induction of mechano-transduction signals. The presented study revealed the chimeric BMHP1 nanofiber induced higher axon regeneration and myelniation around the cavity and motor neuron function was encouraged to improve with less inflammatory response following SCI in rats. These effects were possibly due to nanostructured topography and mechano-transduction signals derived from hydrogel at low concentration.

  7. Alignment of Astrocytes Increases Neuronal Growth in Three-Dimensional Collagen Gels and Is Maintained Following Plastic Compression to Form a Spinal Cord Repair Conduit

    OpenAIRE

    East, Emma; de Oliveira, Daniela Blum; Golding, Jon P.; Phillips, James B.

    2010-01-01

    After injury to the spinal cord, reactive astrocytes form a glial scar consisting of highly ramified cell processes that constitute a major impediment to repair, partly due to their lack of orientation and guidance for regenerating axons. In some nonmammalian vertebrates, successful central nervous system regeneration is attributed to the alignment of reactive glia, which guide axons across the lesion site. Here, a three-dimensional mammalian cell-seeded collagen gel culture system was used t...

  8. A New Population of Parvocellular Oxytocin Neurons Controlling Magnocellular Neuron Activity and Inflammatory Pain Processing.

    Science.gov (United States)

    Eliava, Marina; Melchior, Meggane; Knobloch-Bollmann, H Sophie; Wahis, Jérôme; da Silva Gouveia, Miriam; Tang, Yan; Ciobanu, Alexandru Cristian; Triana Del Rio, Rodrigo; Roth, Lena C; Althammer, Ferdinand; Chavant, Virginie; Goumon, Yannick; Gruber, Tim; Petit-Demoulière, Nathalie; Busnelli, Marta; Chini, Bice; Tan, Linette L; Mitre, Mariela; Froemke, Robert C; Chao, Moses V; Giese, Günter; Sprengel, Rolf; Kuner, Rohini; Poisbeau, Pierrick; Seeburg, Peter H; Stoop, Ron; Charlet, Alexandre; Grinevich, Valery

    2016-03-16

    Oxytocin (OT) is a neuropeptide elaborated by the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Magnocellular OT neurons of these nuclei innervate numerous forebrain regions and release OT into the blood from the posterior pituitary. The PVN also harbors parvocellular OT cells that project to the brainstem and spinal cord, but their function has not been directly assessed. Here, we identified a subset of approximately 30 parvocellular OT neurons, with collateral projections onto magnocellular OT neurons and neurons of deep layers of the spinal cord. Evoked OT release from these OT neurons suppresses nociception and promotes analgesia in an animal model of inflammatory pain. Our findings identify a new population of OT neurons that modulates nociception in a two tier process: (1) directly by release of OT from axons onto sensory spinal cord neurons and inhibiting their activity and (2) indirectly by stimulating OT release from SON neurons into the periphery. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. A high-fat jelly diet restores bioenergetic balance and extends lifespan in the presence of motor dysfunction and lumbar spinal cord motor neuron loss in TDP-43A315T mutant C57BL6/J mice

    Directory of Open Access Journals (Sweden)

    Karen S. Coughlan

    2016-09-01

    Full Text Available Transgenic transactivation response DNA-binding protein 43 (TDP-43 mice expressing the A315T mutation under control of the murine prion promoter progressively develop motor function deficits and are considered a new model for the study of amyotrophic lateral sclerosis (ALS; however, premature sudden death resulting from intestinal obstruction halts disease phenotype progression in 100% of C57BL6/J congenic TDP-43A315T mice. Similar to our recent results in SOD1G93A mice, TDP-43A315T mice fed a standard pellet diet showed increased 5′ adenosine monophosphate-activated protein kinase (AMPK activation at postnatal day (P80, indicating elevated energetic stress during disease progression. We therefore investigated the effects of a high-fat jelly diet on bioenergetic status and lifespan in TDP-43A315T mice. In contrast to standard pellet-fed mice, mice fed high-fat jelly showed no difference in AMPK activation up to P120 and decreased phosphorylation of acetly-CoA carboxylase (ACC at early-stage time points. Exposure to a high-fat jelly diet prevented sudden death and extended survival, allowing development of a motor neuron disease phenotype with significantly decreased body weight from P80 onward that was characterised by deficits in Rotarod abilities and stride length measurements. Development of this phenotype was associated with a significant motor neuron loss as assessed by Nissl staining in the lumbar spinal cord. Our work suggests that a high-fat jelly diet improves the pre-clinical utility of the TDP-43A315T model by extending lifespan and allowing the motor neuron disease phenotype to progress, and indicates the potential benefit of this diet in TDP-43-associated ALS.

  10. Spinal fusion

    Science.gov (United States)

    ... Herniated disk - fusion; Spinal stenosis - fusion; Laminectomy - fusion Patient Instructions Bathroom safety - adults Preventing falls Preventing falls - what to ask your doctor Spine surgery - discharge Surgical wound care - open Images Scoliosis Spinal ...

  11. Optogenetically enhanced axon regeneration: motor versus sensory neuron-specific stimulation.

    Science.gov (United States)

    Ward, Patricia J; Clanton, Scott L; English, Arthur W

    2018-02-01

    Brief neuronal activation in injured peripheral nerves is both necessary and sufficient to enhance motor axon regeneration, and this effect is specific to the activated motoneurons. It is less clear whether sensory neurons respond in a similar manner to neuronal activation following peripheral axotomy. Further, it is unknown to what extent enhancement of axon regeneration with increased neuronal activity relies on a reflexive interaction within the spinal circuitry. We used mouse genetics and optical tools to evaluate the precision and selectivity of system-specific neuronal activation to enhance axon regeneration in a mixed nerve. We evaluated sensory and motor axon regeneration in two different mouse models expressing the light-sensitive cation channel, channelrhodopsin (ChR2). We selectively activated either sensory or motor axons using light stimulation combined with transection and repair of the sciatic nerve. Regardless of genotype, the number of ChR2-positive neurons whose axons had regenerated successfully was greater following system-specific optical treatment, with no effect on the number of ChR2-negative neurons (whether motor or sensory neurons). We conclude that acute system-specific neuronal activation is sufficient to enhance both motor and sensory axon regeneration. This regeneration-enhancing effect is likely cell autonomous. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  12. M1 corticospinal mirror neurons and their role in movement suppression during action observation.

    Science.gov (United States)

    Vigneswaran, Ganesh; Philipp, Roland; Lemon, Roger N; Kraskov, Alexander

    2013-02-04

    Evidence is accumulating that neurons in primary motor cortex (M1) respond during action observation, a property first shown for mirror neurons in monkey premotor cortex. We now show for the first time that the discharge of a major class of M1 output neuron, the pyramidal tract neuron (PTN), is modulated during observation of precision grip by a human experimenter. We recorded 132 PTNs in the hand area of two adult macaques, of which 65 (49%) showed mirror-like activity. Many (38 of 65) increased their discharge during observation (facilitation-type mirror neuron), but a substantial number (27 of 65) exhibited reduced discharge or stopped firing (suppression-type). Simultaneous recordings from arm, hand, and digit muscles confirmed the complete absence of detectable muscle activity during observation. We compared the discharge of the same population of neurons during active grasp by the monkeys. We found that facilitation neurons were only half as active for action observation as for action execution, and that suppression neurons reversed their activity pattern and were actually facilitated during execution. Thus, although many M1 output neurons are active during action observation, M1 direct input to spinal circuitry is either reduced or abolished and may not be sufficient to produce overt muscle activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation Pediatric Spinal ... Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation Pediatric Spinal ...

  14. Detecting bladder fullness through the ensemble activity patterns of the spinal cord unit population in a somatovisceral convergence environment

    Science.gov (United States)

    Park, Jae Hong; Kim, Chang-Eop; Shin, Jaewoo; Im, Changkyun; Koh, Chin Su; Seo, In Seok; Kim, Sang Jeong; Shin, Hyung-Cheul

    2013-10-01

    Objective. Chronic monitoring of the state of the bladder can be used to notify patients with urinary dysfunction when the bladder should be voided. Given that many spinal neurons respond both to somatic and visceral inputs, it is necessary to extract bladder information selectively from the spinal cord. Here, we hypothesize that sensory information with distinct modalities should be represented by the distinct ensemble activity patterns within the neuronal population and, therefore, analyzing the activity patterns of the neuronal population could distinguish bladder fullness from somatic stimuli. Approach. We simultaneously recorded 26-27 single unit activities in response to bladder distension or tactile stimuli in the dorsal spinal cord of each Sprague-Dawley rat. In order to discriminate between bladder fullness and tactile stimulus inputs, we analyzed the ensemble activity patterns of the entire neuronal population. A support vector machine (SVM) was employed as a classifier, and discrimination performance was measured by k-fold cross-validation tests. Main results. Most of the units responding to bladder fullness also responded to the tactile stimuli (88.9-100%). The SVM classifier precisely distinguished the bladder fullness from the somatic input (100%), indicating that the ensemble activity patterns of the unit population in the spinal cord are distinct enough to identify the current input modality. Moreover, our ensemble activity pattern-based classifier showed high robustness against random losses of signals. Significance. This study is the first to demonstrate that the two main issues of electroneurographic monitoring of bladder fullness, low signals and selectiveness, can be solved by an ensemble activity pattern-based approach, improving the feasibility of chronic monitoring of bladder fullness by neural recording.

  15. Properties of bilateral spinocerebellar activation of cerebellar cortical neurons

    Directory of Open Access Journals (Sweden)

    Pontus eGeborek

    2014-10-01

    Full Text Available We aimed to explore the cerebellar cortical inputs from two spinocerebellar pathways, the spinal border cell-component of the ventral spinocerebellar tract (SBC-VSCT and the dorsal spinocerebellar tract (DSCT, respectively, in the sublobule C1 of the cerebellar posterior lobe. The two pathways were activated by electrical stimulation of the contralateral lateral funiculus (coLF and the ipsilateral LF (iLF at lower thoracic levels. Most granule cells in sublobule C1 did not respond at all but part of the granule cell population displayed high-intensity responses to either coLF or iLF stimulation. As a rule, Golgi cells and Purkinje cell simple spikes responded to input from both LFs, although Golgi cells could be more selective. In addition, a small population of granule cells responded to input from both the coLF and the iLF. However, in these cases, similarities in the temporal topography and magnitude of the responses suggested that the same axons were stimulated from the two LFs, i.e. that the axons of individual spinocerebellar neurons could be present in both funiculi. This was also confirmed for a population of spinal neurons located within known locations of SBC-VSCT neurons and dorsal horn DSCT neurons. We conclude that bilateral spinocerebellar responses can occur in cerebellar granule cells, but the VSCT and DSCT systems that provide the input can also be organized bilaterally. The implications for the traditional functional separation of VSCT and DSCT systems and the issue whether granule cells primarily integrate functionally similar information or not are discussed.

  16. Effective synaptome analysis of itch-mediating neurons in the spinal cord: A novel immunohistochemical methodology using high-voltage electron microscopy.

    Science.gov (United States)

    Satoh, Keita; Takanami, Keiko; Murata, Kazuyoshi; Kawata, Mitsuhiro; Sakamoto, Tatsuya; Sakamoto, Hirotaka

    2015-07-10

    Transmission electron microscopy (TEM) is used for three-dimensional (3-D) analysis of synaptic connections in neuroscience research. However, 3-D reconstruction of the synapses using serial ultrathin sections is a powerful but tedious approach requiring advanced technical skills. High-voltage electron microscopy (HVEM) allows examination of thicker sections of biological specimens due to the increased penetration of the more accelerated electrons, which is useful to analyze the 3-D structure of biological specimens. However, it is still difficult to visualize the neural networks and synaptic connections in 3-D using HVEM because of insufficient and non uniform heavy metal staining in the membranous structures in semi-thin sections. Here, we present the successful chemical 3-D neuroanatomy of the rat spinal dorsal horn at the ultrastructural level as a first step for effective synaptome analysis by applying a high-contrast en bloc staining method to immune-HVEM tomography. Our new approach made it possible to examine many itch-mediating synaptic connections and neural networks in the spinal cord simultaneously using HVEM tomography. This novel 3-D electron microscopy is very useful for the analysis of synaptic structure and the chemical neuroanatomy at the 3-D ultrastructural level. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Early Afferent Activity from the Facet Joint after Painful Trauma to its Capsule Potentiates Neuronal Excitability and Glutamate Signaling in the Spinal Cord

    OpenAIRE

    Crosby, Nathan D.; Gilliland, Taylor M.; Winkelstein, Beth A.

    2014-01-01

    Cervical facet joint injury induces persistent pain and central sensitization. Preventing the peripheral neuronal signals that initiate sensitization attenuates neuropathic pain. Yet, there is no clear relationship between facet joint afferent activity, development of central sensitization, and pain, which may be hindering effective treatments for this pain syndrome. This study investigates how afferent activity from the injured cervical facet joint affects induction of behavioral sensitivity...

  18. LACK OF ANALGESIC EFFICACY OF SPINAL ONDANSETRON ON THERMAL AND MECHANICAL HYPERSENSITIVITY FOLLOWING SPINAL NERVE LIGATION IN THE RAT

    OpenAIRE

    Peters, Christopher M.; Hayashida, Ken-ichiro; Ewan, Eric E.; Nakajima, Kunie; Obata, Hideaki; Xu, Qinghao; Yaksh, Tony L.; Eisenach, James C.

    2010-01-01

    The balance between descending inhibition and facilitation is thought to be disturbed in chronic pain states. Increased facilitation by spinally released serotonin has been suggested by demonstration that mechanically evoked neuronal responses of wide dynamic range neurons are inhibited by 5-HT3 receptor antagonists in rats following spinal nerve ligation (SNL) but not sham operation. Despite these physiologic data, the effects of spinal 5-HT3 receptor blockade on behavioral hypersensitivity ...

  19. Comparative distribution and in vitro activities of the urotensin II-related peptides URP1 and URP2 in zebrafish: evidence for their colocalization in spinal cerebrospinal fluid-contacting neurons.

    Directory of Open Access Journals (Sweden)

    Feng B Quan

    Full Text Available Urotensin II (UII is an evolutionarily conserved neuropeptide initially isolated from teleost fish on the basis of its smooth muscle-contracting activity. Subsequent studies have demonstrated the occurrence of several UII-related peptides (URPs, such that the UII family is now known to include four paralogue genes called UII, URP, URP1 and URP2. These genes probably arose through the two rounds of whole genome duplication that occurred during early vertebrate evolution. URP has been identified both in tetrapods and teleosts. In contrast, URP1 and URP2 have only been observed in ray-finned and cartilaginous fishes, suggesting that both genes were lost in the tetrapod lineage. In the present study, the distribution of urp1 mRNA compared to urp2 mRNA is reported in the central nervous system of zebrafish. In the spinal cord, urp1 and urp2 mRNAs were mainly colocalized in the same cells. These cells were also shown to be GABAergic and express the gene encoding the polycystic kidney disease 2-like 1 (pkd2l1 channel, indicating that they likely correspond to cerebrospinal fluid-contacting neurons. In the hindbrain, urp1-expressing cells were found in the intermediate reticular formation and the glossopharyngeal-vagal motor nerve nuclei. We also showed that synthetic URP1 and URP2 were able to induce intracellular calcium mobilization in human UII receptor (hUT-transfected CHO cells with similar potencies (pEC50=7.99 and 7.52, respectively albeit at slightly lower potencies than human UII and mammalian URP (pEC50=9.44 and 8.61, respectively. The functional redundancy of URP1 and URP2 as well as the colocalization of their mRNAs in the spinal cord suggest the robustness of this peptidic system and its physiological importance in zebrafish.

  20. Ozone (O{sub 3}) elicits neurotoxicity in spinal cord neurons (SCNs) by inducing ER Ca{sup 2+} release and activating the CaMKII/MAPK signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yun; Lin, Xiaowen; Zhao, XueJun; Xie, Juntian; JunNan, Wang; Sun, Tao; Fu, Zhijian, E-mail: zhijian_fu@163.com

    2014-11-01

    Ozone (O{sub 3}) is widely used in the treatment of spinal cord related diseases. Excess or accumulation of this photochemical air can however be neurotoxic. In this study, in vitro cultured Wister rat spinal cord neurons (SCNs) were used to investigate the detrimental effects and underlying mechanisms of O{sub 3}. Ozone in a dose-dependent manner inhibited cell viability at a range of 20 to 500 μg/ml, with the dose at 40 μg/ml resulting in a decrease of cell viability to 75%. The cell death after O{sub 3} exposure was related to endoplasmic reticulum (ER) calcium (Ca{sup 2+}) release. Intracellular Ca{sup 2+} chelator, ER stabilizer (inositol 1,4,5-trisphosphate receptor (IP3R) antagonist and ryanodine receptor (RyR) antagonist) and calcium/calmodulin-dependent protein kinase II (CaMKII) antagonist could effectively block Ca{sup 2+} mobilization and inhibit cell death following 40 μg/ml O{sub 3} exposure. In addition, ER Ca{sup 2+} release due to O{sub 3} exposure enhanced phospho-p38 and phospho-JNK levels and apoptosis of SCNs through activating CaMKII. Based on these results, we confirm that ozone elicits neurotoxicity in SCNs via inducing ER Ca{sup 2+} release and activating CaMKII/MAPK signaling pathway. Therefore, physicians should get attention to the selection of treatment concentrations of oxygen/ozone. And, approaches, such as chelating intracellular Ca{sup 2+} and stabilizing neuronal Ca{sup 2+} homeostasis could effectively ameliorate the neurotoxicity of O{sub 3}. - Highlights: • Exposure to O{sub 3} can reduce the viability of SCNs and cause the cell death. • Exposure to O{sub 3} can trigger RyR and IP3R dependent intracellular Ca{sup 2+} release. • Exposure to O{sub 3} can enhance the phospho-CaMKII, phospho-JNK and phospho-p38 levels.

  1. An N-methyl-D-aspartate receptor mediated large, low-frequency, spontaneous excitatory postsynaptic current in neonatal rat spinal dorsal horn neurons.

    Science.gov (United States)

    Thomson, L M; Zeng, J; Terman, G W

    2006-09-01

    Examples of spontaneous oscillating neural activity contributing to both pathological and physiological states are abundant throughout the CNS. Here we report a spontaneous oscillating intermittent synaptic current located in lamina I of the neonatal rat spinal cord dorsal horn. The spontaneous oscillating intermittent synaptic current is characterized by its large amplitude, slow decay time, and low-frequency. We demonstrate that post-synaptic N-methyl-D-aspartate receptors (NMDARs) mediate the spontaneous oscillating intermittent synaptic current, as it is inhibited by magnesium, bath-applied d-2-amino-5-phosphonovalerate (APV), or intracellular MK-801. The NR2B subunit of the NMDAR appears important to this phenomenon, as the NR2B subunit selective NMDAR antagonist, alpha-(4-hydroxphenyl)-beta-methyl-4-benzyl-1-piperidineethanol tartrate (ifenprodil), also partially inhibited the spontaneous oscillating intermittent synaptic current. Inhibition of spontaneous glutamate release by the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or the mu-opioid receptor agonist [D-Ala2, N-Me-Phe4, Gly5] enkephalin-ol (DAMGO) inhibited the spontaneous oscillating intermittent synaptic current frequency. Marked inhibition of spontaneous oscillating intermittent synaptic current frequency by tetrodotoxin (TTX), but not post-synaptic N-(2,6-dimethylphenylcarbamoylmethyl)triethylammonium bromide (QX-314), suggests that the glutamate release important to the spontaneous oscillating intermittent synaptic current is dependent on active neural processes. Conversely, increasing dorsal horn synaptic glutamate release by GABAA or glycine inhibition increased spontaneous oscillating intermittent synaptic current frequency. Moreover, inhibiting glutamate transporters with threo-beta-benzyloxyaspartic acid (DL-TBOA) increased spontaneous oscillating intermittent synaptic current frequency and decay time. A possible functional role of this spontaneous NMDAR

  2. Muscles in a mouse model of spinal muscular atrophy show profound defects in neuromuscular development even in the absence of failure in neuromuscular transmission or loss of motor neurons.

    Science.gov (United States)

    Lee, Young Il; Mikesh, Michelle; Smith, Ian; Rimer, Mendell; Thompson, Wesley

    2011-08-15

    A mouse model of the devastating human disease "spinal muscular atrophy" (SMA) was used to investigate the severe muscle weakness and spasticity that precede the death of these animals near the end of the 2nd postnatal week. Counts of motor units to the soleus muscle as well as of axons in the soleus muscle nerve showed no loss of motor neurons. Similarly, neither immunostaining of neuromuscular junctions nor the measurement of the tension generated by nerve stimulation gave evidence of any significant impairment in neuromuscular transmission, even when animals were maintained up to 5days longer via a supplementary diet. However, the muscles were clearly weaker, generating less than half their normal tension. Weakness in 3 muscles examined in the study appears due to a severe but uniform reduction in muscle fiber size. The size reduction results from a failure of muscle fibers to grow during early postnatal development and, in soleus, to a reduction in number of fibers generated. Neuromuscular development is severely delayed in these mutant animals: expression of myosin heavy chain isoforms, the elimination of polyneuronal innervation, the maturation in the shape of the AChR plaque, the arrival of SCs at the junctions and their coverage of the nerve terminal, the development of junctional folds. Thus, if SMA in this particular mouse is a disease of motor neurons, it can act in a manner that does not result in their death or disconnection from their targets but nonetheless alters many aspects of neuromuscular development. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Shaping the Output of Lumbar Flexor Motoneurons by Sacral Neuronal Networks.

    Science.gov (United States)

    Cherniak, Meir; Anglister, Lili; Lev-Tov, Aharon

    2017-02-01

    The ability to improve motor function in spinal cord injury patients by reactivating spinal central pattern generators (CPGs) requires the elucidation of neurons and pathways involved in activation and modulation of spinal networks in accessible experimental models. Previously we reported on adrenoceptor-dependent sacral control of lumbar flexor motoneuron firing in newborn rats. The current work focuses on clarification of the circuitry and connectivity involved in this unique modulation and its potential use. Using surgical manipulations of the spinal gray and white matter, electrophysiological recordings, and confocal microscopy mapping, we found that methoxamine (METH) activation of sacral networks within the ventral aspect of S2 segments was sufficient to produce alternating rhythmic bursting (0.15-1 Hz) in lumbar flexor motoneurons. This lumbar rhythm depended on continuity of the ventral funiculus (VF) along the S2-L2 segments. Interrupting the VF abolished the rhythm and replaced it by slow unstable bursting. Calcium imaging of S1-S2 neurons, back-labeled via the VF, revealed that ∼40% responded to METH, mostly by rhythmic firing. All uncrossed projecting METH responders and ∼70% of crossed projecting METH responders fired with the concurrent ipsilateral motor output, while the rest (∼30%) fired with the contralateral motor output. We suggest that METH-activated sacral CPGs excite ventral clusters of sacral VF neurons to deliver the ascending drive required for direct rhythmic activation of lumbar flexor motoneurons. The capacity of noradrenergic-activated sacral CPGs to modulate the activity of lumbar networks via sacral VF neurons provides a novel way to recruit rostral lumbar motoneurons and modulate the output required to execute various motor behaviors. Spinal central pattern generators (CPGs) produce the rhythmic output required for coordinating stepping and stabilizing the body axis during movements. Electrical stimulation and exogenous drugs

  4. An Agonist of the Protective Factor SIRT1 Improves Functional Recovery and Promotes Neuronal Survival by Attenuating Inflammation after Spinal Cord Injury.

    Science.gov (United States)

    Chen, Haihong; Ji, Hao; Zhang, Ming; Liu, Zude; Lao, Lifeng; Deng, Chao; Chen, Jianwei; Zhong, Guibin

    2017-03-15

    Targeting posttraumatic inflammation is crucial for improving locomotor function. SIRT1 has been shown to play a critical role in disease processes such as hepatic inflammation, rheumatoid arthritis, and acute lung inflammation by regulating inflammation. However, the role of SIRT1 in spinal cord injury (SCI) is unknown. We hypothesized that SIRT1 plays an important role in improving locomotor function after SCI by regulating neuroinflammation. In this study, we investigate the effect of SIRT1 in SCI using pharmacological intervention (SRT1720) and the Mx1-Cre/loxP recombination system to knock out target genes. First, we found that SIRT1 expression at the injured lesion site of wild-type (WT) mice (C57BL/6) decreased 4 h after SCI and lasted for 3 d. Moreover, administration of SRT1720, an agonist of SIRT1, to WT mice significantly improved functional recovery for up to 28 d after injury by reducing the levels of proinflammatory cytokines, the number of M1 macrophages, the number of macrophages/microglia, and the accumulation of perivascular macrophages. In contrast, administration of SRT1720 to SIRT1 knock-out (KO) mice did not improve locomotor recovery or attenuate inflammation. Furthermore, SIRT1 KO mice exhibited worse locomotor recovery, increased levels of inflammatory cytokines, and more M1 macrophages and perivascular macrophages than those of WT mice after SCI. Together, these findings indicate that SRT1720, an SIRT1 agonist, can improve functional recovery by attenuating inflammation after SCI. Therefore, SIRT1 is not only a protective factor but also an anti-inflammatory molecule that exerts beneficial effects on locomotor function after SCI. SIGNIFICANCE STATEMENT Posttraumatic inflammation plays a central role in regulating the pathogenesis of spinal cord injury (SCI). Here, new data show that administration of SRT1720, an SIRT1 agonist, to wild-type (WT) mice significantly improved outcomes after SCI, most likely by reducing the levels of

  5. Metabotropic glutamate receptor-5 and protein kinase C-epsilon increase in dorsal root ganglion neurons and spinal glial activation in an adolescent rat model of painful neck injury.

    Science.gov (United States)

    Weisshaar, Christine L; Dong, Ling; Bowman, Alex S; Perez, Federico M; Guarino, Benjamin B; Sweitzer, Sarah M; Winkelstein, Beth A

    2010-12-01

    There is growing evidence that neck pain is common in adolescence and is a risk factor for the development of chronic neck pain in adulthood. The cervical facet joint and its capsular ligament is a common source of pain in the neck in adults, but its role in adolescent pain remains unknown. The aim of this study was to define the biomechanics, behavioral sensitivity, and indicators of neuronal and glial activation in an adolescent model of mechanical facet joint injury. A bilateral C6-C7 facet joint distraction was imposed in an adolescent rat and biomechanical metrics were measured during injury. Following injury, forepaw mechanical hyperalgesia was measured, and protein kinase C-epsilon (PKCɛ) and metabotropic glutamate receptor-5 (mGluR5) expression in the dorsal root ganglion and markers of spinal glial activation were assessed. Joint distraction induced significant mechanical hyperalgesia during the 7 days post-injury (p capsule during injury were 32.8 ± 12.9%, which were consistent with the strains associated with comparable degrees of hypersensitivity in the adult rat. These results suggest that adolescents may have a lower tissue tolerance to induce pain and associated nociceptive response than do adults.

  6. Caudalized human iPSC-derived neural progenitor cells produce neurons and glia but fail to restore function in an early chronic spinal cord injury model

    Science.gov (United States)

    Nutt, Samuel E.; Chang, Eun-Ah; Suhr, Steven T.; Schlosser, Laura O.; Mondello, Sarah E.; Moritz, Chet T.; Cibelli, Jose B.; Horner, Philip J.

    2014-01-01

    Neural progenitor cells (NPCs) have shown modest potential and some side effects (e.g. allodynia) for treatment of spinal cord injury (SCI). In only a few cases, however, have NPCs shown promise at the chronic stage. Given the 1.275 million people living with chronic paralysis, there is a significant need to rigorously evaluate the cell types and methods for safe and efficacious treatment of this devastating condition. For the first time, we examined the pre-clinical potential of NPCs derived from human induced pluripotent stem cells (hiPSCs) to repair chronic SCI. hiPSCs were differentiated into region-specific (i.e. caudal) NPCs, then transplanted into a new, clinically relevant model of early chronic cervical SCI. We established the conditions for successful transplantation of caudalized hiPSC-NPCs and demonstrate their remarkable ability to integrate and produce multiple neural lineages in the early chronic injury environment. In contrast to prior reports in acute and sub-acute injury models, survival and integration of hiPSC-derived neural cells in the early chronic cervical model did not lead to significant improvement in forelimb function or induce allodynia. These data indicate that while hiPSCs show promise, future work needs to focus on the specific hiPSC-derivatives or co-therapies that will restore function in the early chronic injury setting. PMID:23891888

  7. Corticospinal mirror neurons.

    Science.gov (United States)

    Kraskov, A; Philipp, R; Waldert, S; Vigneswaran, G; Quallo, M M; Lemon, R N

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited 'classical' mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation ('suppression mirror-neurons'). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others.

  8. Descending Command Neurons in the Brainstem that Halt Locomotion

    DEFF Research Database (Denmark)

    Bouvier, Julien; Caggiano, Vittorio; Leiras, Roberto

    2015-01-01

    identifiable brainstem populations to a potential locomotor stop signal, we used developmental genetics and considered a discrete neuronal population in the reticular formation: the V2a neurons. We find that those neurons constitute a major excitatory pathway to locomotor areas of the ventral spinal cord....... Selective activation of V2a neurons of the rostral medulla stops ongoing locomotor activity, owing to an inhibition of premotor locomotor networks in the spinal cord. Moreover, inactivation of such neurons decreases spontaneous stopping in vivo. Therefore, the V2a "stop neurons" represent a glutamatergic...

  9. Abnormal mitochondrial transport and morphology as early pathological changes in human models of spinal muscular atrophy

    Directory of Open Access Journals (Sweden)

    Chong-Chong Xu

    2016-01-01

    Full Text Available Spinal muscular atrophy (SMA, characterized by specific degeneration of spinal motor neurons, is caused by mutations in the survival of motor neuron 1, telomeric (SMN1 gene and subsequent decreased levels of functional SMN. How the deficiency of SMN, a ubiquitously expressed protein, leads to spinal motor neuron-specific degeneration in individuals affected by SMA remains unknown. In this study, we examined the role of SMN in mitochondrial axonal transport and morphology in human motor neurons by generating SMA type 1 patient-specific induced pluripotent stem cells (iPSCs and differentiating these cells into spinal motor neurons. The initial specification of spinal motor neurons was not affected, but these SMA spinal motor neurons specifically degenerated following long-term culture. Moreover, at an early stage in SMA spinal motor neurons, but not in SMA forebrain neurons, the number of mitochondria, mitochondrial area and mitochondrial transport were significantly reduced in axons. Knocking down of SMN expression led to similar mitochondrial defects in spinal motor neurons derived from human embryonic stem cells, confirming that SMN deficiency results in impaired mitochondrial dynamics. Finally, the application of N-acetylcysteine (NAC mitigated the impairment in mitochondrial transport and morphology and rescued motor neuron degeneration in SMA long-term cultures. Furthermore, NAC ameliorated the reduction in mitochondrial membrane potential in SMA spinal motor neurons, suggesting that NAC might rescue apoptosis and motor neuron degeneration by improving mitochondrial health. Overall, our data demonstrate that SMN deficiency results in abnormal mitochondrial transport and morphology and a subsequent reduction in mitochondrial health, which are implicated in the specific degeneration of spinal motor neurons in SMA.

  10. Abnormal mitochondrial transport and morphology as early pathological changes in human models of spinal muscular atrophy

    Science.gov (United States)

    Xu, Chong-Chong; Denton, Kyle R.; Wang, Zhi-Bo; Zhang, Xiaoqing; Li, Xue-Jun

    2016-01-01

    ABSTRACT Spinal muscular atrophy (SMA), characterized by specific degeneration of spinal motor neurons, is caused by mutations in the survival of motor neuron 1, telomeric (SMN1) gene and subsequent decreased levels of functional SMN. How the deficiency of SMN, a ubiquitously expressed protein, leads to spinal motor neuron-specific degeneration in individuals affected by SMA remains unknown. In this study, we examined the role of SMN in mitochondrial axonal transport and morphology in human motor neurons by generating SMA type 1 patient-specific induced pluripotent stem cells (iPSCs) and differentiating these cells into spinal motor neurons. The initial specification of spinal motor neurons was not affected, but these SMA spinal motor neurons specifically degenerated following long-term culture. Moreover, at an early stage in SMA spinal motor neurons, but not in SMA forebrain neurons, the number of mitochondria, mitochondrial area and mitochondrial transport were significantly reduced in axons. Knocking down of SMN expression led to similar mitochondrial defects in spinal motor neurons derived from human embryonic stem cells, confirming that SMN deficiency results in impaired mitochondrial dynamics. Finally, the application of N-acetylcysteine (NAC) mitigated the impairment in mitochondrial transport and morphology and rescued motor neuron degeneration in SMA long-term cultures. Furthermore, NAC ameliorated the reduction in mitochondrial membrane potential in SMA spinal motor neurons, suggesting that NAC might rescue apoptosis and motor neuron degeneration by improving mitochondrial health. Overall, our data demonstrate that SMN deficiency results in abnormal mitochondrial transport and morphology and a subsequent reduction in mitochondrial health, which are implicated in the specific degeneration of spinal motor neurons in SMA. PMID:26586529

  11. Making sense out of spinal cord somatosensory development

    Science.gov (United States)

    Seal, Rebecca P.

    2016-01-01

    The spinal cord integrates and relays somatosensory input, leading to complex motor responses. Research over the past couple of decades has identified transcription factor networks that function during development to define and instruct the generation of diverse neuronal populations within the spinal cord. A number of studies have now started to connect these developmentally defined populations with their roles in somatosensory circuits. Here, we review our current understanding of how neuronal diversity in the dorsal spinal cord is generated and we discuss the logic underlying how these neurons form the basis of somatosensory circuits. PMID:27702783

  12. Acupuncture Points and Their Relationship with Multireceptive Fields of Neurons

    OpenAIRE

    Salvador Quiroz-González; Sergio Torres-Castillo; Rosa Estela López-Gómez; Ismael Jiménez Estrada

    2017-01-01

    In Traditional Chinese Medicine, acupuncture points (APs) have been emphasized as key elements that generate the therapeutic effects of acupuncture. At the spinal cord or supraspinal level, sensory neurons located in the dorsal horn receive an extensive supply of sensory information from skin and muscle receptors through peripheral afferent nerves. The stimulated skin area that influences the activity of a spinal sensory neuron is known as the peripheral receptive field (RF) of that neuron. B...

  13. Glutamate acts as a neurotransmitter for gastrin releasing peptide-sensitive and insensitive itch-related synaptic transmission in mammalian spinal cord

    Directory of Open Access Journals (Sweden)

    Ling Jennifer

    2011-06-01

    Full Text Available Abstract Itch sensation is one of the major sensory experiences of human and animals. Recent studies have proposed that gastrin releasing peptide (GRP is a key neurotransmitter for itch in spinal cord. However, no direct evidence is available to indicate that GRP actually mediate responses between primary afferent fibers and dorsal horn neurons. Here we performed integrative neurobiological experiments to test this question. We found that a small population of rat dorsal horn neurons responded to GRP application with increases in calcium signaling. Whole-cell patch-clamp recordings revealed that a part of superficial dorsal horn neurons responded to GRP application with the increase of action potential firing in adult rats and mice, and these dorsal horn neurons received exclusively primary afferent C-fiber inputs. On the other hands, few Aδ inputs receiving cells were found to be GRP positive. Finally, we found that evoked sensory responses between primary afferent C fibers and GRP positive superficial dorsal horn neurons are mediated by glutamate but not GRP. CNQX, a blocker of AMPA and kainate (KA receptors, completely inhibited evoked EPSCs, including in those Fos-GFP positive dorsal horn cells activated by itching. Our findings provide the direct evidence that glutamate is the principal excitatory transmitter between C fibers and GRP positive dorsal horn neurons. Our results will help to understand the neuronal mechanism of itch and aid future treatment for patients with pruritic disease.

  14. Spinal injury

    Science.gov (United States)

    ... 2016. Kaji AH, Newton EJ, Hockberger RS. Spinal injuries. In: Marx JA, Hockberger RS, Walls RM, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier ...

  15. Spinal Infections

    Science.gov (United States)

    ... Epidural Steroid Injections Exercise: The Backbone of Spine Treatment Spondylolisthesis ... by bacteria or fungal organisms. Spinal infections may occur following surgery or spontaneously in patients with certain risk factors. ...

  16. Spinal Stenosis

    Science.gov (United States)

    ... images of the back and spinal canal A magnetic resonance imaging (MRI) scan of the spine to ... trigger or worsen pain and disability such as lifting heavy objects or walking long distances. Talk to ...

  17. Assessing attitudes toward spinal immobilization.

    Science.gov (United States)

    Bouland, Andrew J; Jenkins, J Lee; Levy, Matthew J

    2013-10-01

    Prospective studies have improved knowledge of prehospital spinal immobilization. The opinion of Emergency Medical Services (EMS) providers regarding spinal immobilization is unknown, as is their knowledge of recent research advances. To examine the attitudes, knowledge, and comfort of prehospital and Emergency Department (ED) EMS providers regarding spinal immobilization performed under a non-selective protocol. An online survey was conducted from May to July of 2011. Participants were drawn from the Howard County Department of Fire and Rescue Services and the Howard County General Hospital ED. The survey included multiple choice questions and responses on a modified Likert scale. Correlation analysis and descriptive data were used to analyze results. Comfort using the Kendrick Extrication Device was low among ED providers. Experienced providers were more likely to indicate comfort using this device. Respondents often believed that spinal immobilization is appropriate in the management of penetrating trauma to the chest and abdomen. Reported use of padding decreased along with the frequency with which providers practice and encounter immobilized patients. Respondents often indicated that they perform spinal immobilization due solely to mechanism of injury. Providers who feel as if spinal immobilization is often performed unnecessarily were more likely to agree that immobilization causes an unnecessary delay in patient care. The results demonstrate the need for improved EMS education in the use of the Kendrick Extrication Device, backboard padding, and spinal immobilization in the management of penetrating trauma. The attitudes highlighted in this study are relevant to the implementation of a selective spinal immobilization protocol. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Spinal infections

    International Nuclear Information System (INIS)

    Tali, E. Turgut; Gueltekin, Serap

    2005-01-01

    Spinal infections have an increasing prevalence among the general population. Definitive diagnosis based solely on clinical grounds is usually not possible and radiological imaging is used in almost all patients. The primary aim of the authors is to present an overview of spinal infections located in epidural, intradural and intramedullary compartments and to provide diagnostic clues regarding different imaging modalities, particularly MRI, to the practicing physicians and radiologists. (orig.)

  19. Spinal cysticercosis

    International Nuclear Information System (INIS)

    Goedert, A.V.; Silva, S.H.F.

    1990-01-01

    Spinal cysticercosis is an extremely uncommon condition. We have examined four patients with complaints that resembled nervous root compression by disk herniation. Myelography was shown to be an efficient method to evaluate spinal involvement, that was characterized by findings of multiple filling defect images (cysts) plus signs of adhesive arachnoiditis. One cyst was found to be mobile. Because of the recent development of medical treatment, a quick and precise diagnosis is of high importance to determine the prognosis of this condition. (author)

  20. Spinal vascular malformations; Spinale Gefaessmalformationen

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, U. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg/Saar (Germany)

    2012-05-15

    Spinal vascular malformations are a group of rare diseases with different clinical presentations ranging from incidental asymptomatic findings to progressive tetraplegia. This article provides an overview about imaging features as well as clinical and therapeutic aspects of spinal arteriovenous malformations, cavernomas and capillary telangiectasia. (orig.) [German] Spinale Gefaessmalformationen sind eine Gruppe seltener Erkrankungen mit unterschiedlichen klinischen Praesentationen, die vom asymptomatischen Zufallsbefund bis zur progredienten Tetraparese reichen. Dieser Artikel gibt einen Ueberblick ueber radiologische Befunde sowie klinische und therapeutische Aspekte von spinalen arteriovenoesen Malformationen, Kavernomen und kapillaeren Teleangiektasien. (orig.)

  1. [Gene expression profile of spinal ventral horn in ALS].

    Science.gov (United States)

    Yamamoto, Masahiko; Tanaka, Fumiaki; Sobue, Gen

    2007-10-01

    The causative pathomechanism of sporadic amyotrophic lateral sclerosis (ALS) is not clearly understood. Using microarray technology combined with laser-captured microdissection, gene expression profiles of degenerating spinal motor neurons as well as spinal ventral horn from autopsied patients with sporadic ALS were examined. Spinal motor neurons showed a distinct gene expression profile from the whole spinal ventral horn. Three percent of genes examined were significantly downregulated, and 1% were upregulated in motor neurons. In contrast with motor neurons, the total spinal ventral horn homogenates demonstrated 0.7% and 0.2% significant upregulation and downregulation of gene expression, respectively. Downregulated genes in motor neurons included those associated with cytoskeleton/axonal transport, transcription and cell surface antigens/receptors, such as dynactin 1 (DCTN1) and early growth response 3 (EGR3). In particular, DCTN1 was markedly downregulated in most residual motor neurons prior to the accumulation of pNF-H and ubiquitylated protein. Promoters for cell death pathway, death receptor 5 (DR5), cyclins C (CCNC) and A1 (CCNA), and caspases were upregulated, whereas cell death inhibitors, acetyl-CoA transporter (ACATN) and NF-kappaB (NFKB) were also upregulated. In terms of spinal ventral horn, the expression of genes related to cell surface antigens/receptors, transcription and cell adhesion/ECM were increased. The gene expression resulting in neurodegenerative and neuroprotective changes were both present in spinal motor neurons and ventral horn. Moreover, Inflammation-related genes, such as belonging to the cytokine family were not, however, significantly upregulated in either motor neurons or ventral horn. The sequence of motor neuron-specific gene expression changes from early DCTN1 downregulation to late CCNC upregulation in sporadic ALS can provide direct information on the genes leading to neurodegeneration and neuronal death, and are helpful

  2. Corticospinal mirror neurons

    Science.gov (United States)

    Kraskov, A.; Philipp, R.; Waldert, S.; Vigneswaran, G.; Quallo, M. M.; Lemon, R. N.

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons’ discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited ‘classical’ mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation (‘suppression mirror-neurons’). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others. PMID:24778371

  3. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Injury Chart Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation ... Injury Chart Spinal Cord Injury Facts and Figures Care and Treatment After SCI Spinal Cord Injury Rehabilitation ...

  4. Spinal Cord Injury 101

    Medline Plus

    Full Text Available menu Understanding Spinal Cord Injury What is a Spinal Cord Injury Levels of Injury and What They Mean Animated Spinal Cord Injury Chart Spinal Cord Injury Facts and Figures Care and ...

  5. Spinal Cord Injury 101

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    Full Text Available ... Cord Injury What is a Spinal Cord Injury Levels of Injury and What They Mean Animated Spinal ... Cord Injury What is a Spinal Cord Injury Levels of Injury and What They Mean Animated Spinal ...

  6. Early functional impairment of sensory-motor connectivity in a mouse model of spinal muscular atrophy

    Science.gov (United States)

    Mentis, George Z.; Blivis, Dvir; Liu, Wenfang; Drobac, Estelle; Crowder, Melissa E.; Kong, Lingling; Alvarez, Francisco J.; Sumner, Charlotte J.; O'Donovan, Michael J.

    2011-01-01

    SUMMARY To define alterations of neuronal connectivity that occur during motor neuron degeneration, we characterized the function and structure of spinal circuitry in spinal muscular atrophy (SMA) model mice. SMA motor neurons show reduced proprioceptive reflexes that correlate with decreased number and function of synapses on motor neuron somata and proximal dendrites. These abnormalities occur at an early stage of disease in motor neurons innervating proximal hindlimb muscles and medial motor neurons innervating axial muscles, but only at end-stage disease in motor neurons innervating distal hindlimb muscles. Motor neuron loss follows afferent synapse loss with the same temporal and topographical pattern. Trichostatin A, which improves motor behavior and survival of SMA mice, partially restores spinal reflexes illustrating the reversibility of these synaptic defects. De-afferentation of motor neurons is an early event in SMA and may be a primary cause of motor dysfunction that is amenable to therapeutic intervention. PMID:21315257

  7. Model-Based Design of Stimulus Trains for Selective Microstimulation of Targeted Neuronal Populations

    National Research Council Canada - National Science Library

    McIntyre, Cameron

    2001-01-01

    ... that accurately reproduced the dynamic firing properties of mammalian neurons, The neuron models were coupled to a three-dimensional finite element model of the spinal cord that solved for the potentials...

  8. Clinico-epidemiologic characteristics of spinal muscular atrophy ...

    African Journals Online (AJOL)

    Rabah M. Shawky

    Deletion;. Chromosome 5;. Mutations. Abstract Spinal muscular atrophy (SMA) is characterized by progressive hypotonia and muscular weakness because of progressive degeneration of alpha motor neuron from anterior horn cells in the spinal cord. It is inherited by an autosomal recessive pattern. The precise frequency of ...

  9. Spinal tumors

    International Nuclear Information System (INIS)

    Goethem, J.W.M. van; Hauwe, L. van den; Oezsarlak, Oe.; Schepper, A.M.A. de; Parizel, P.M.

    2004-01-01

    Spinal tumors are uncommon lesions but may cause significant morbidity in terms of limb dysfunction. In establishing the differential diagnosis for a spinal lesion, location is the most important feature, but the clinical presentation and the patient's age and gender are also important. Magnetic resonance (MR) imaging plays a central role in the imaging of spinal tumors, easily allowing tumors to be classified as extradural, intradural-extramedullary or intramedullary, which is very useful in tumor characterization. In the evaluation of lesions of the osseous spine both computed tomography (CT) and MR are important. We describe the most common spinal tumors in detail. In general, extradural lesions are the most common with metastasis being the most frequent. Intradural tumors are rare, and the majority is extramedullary, with meningiomas and nerve sheath tumors being the most frequent. Intramedullary tumors are uncommon spinal tumors. Astrocytomas and ependymomas comprise the majority of the intramedullary tumors. The most important tumors are documented with appropriate high quality CT or MR images and the characteristics of these tumors are also summarized in a comprehensive table. Finally we illustrate the use of the new World Health Organization (WHO) classification of neoplasms affecting the central nervous system

  10. Optogenetics of the Spinal Cord: Use of Channelrhodopsin Proteins for Interrogation of Spinal Cord Circuits.

    Science.gov (United States)

    Rahman, Habibur; Nam, Youngpyo; Kim, Jae-Hong; Lee, Won-Ha; Suk, Kyoungho

    2017-12-29

    Spinal cord circuits play a key role in receiving and transmitting somatosensory information from the body and the brain. They also contribute to the timing and coordination of complex patterns of movement. Under disease conditions, such as spinal cord injury and neuropathic pain, spinal cord circuits receive pain signals from peripheral nerves, and are involved in pain development via neurotransmitters and inflammatory mediators released from neurons and glial cells. Despite the importance of spinal cord circuits in sensory and motor functions, many questions remain regarding the relationship between activation of specific cells and behavioral responses. Optogenetics offers the possibility of understanding the complex cellular activity and mechanisms of spinal cord circuits, as well as having therapeutic potential for addressing spinal cord-related disorders. In this review, we discuss recent findings in optogenetic research employing the channelrhodopsin protein to assess the function of specific neurons and glia in spinal cord circuits ex vivo and in vivo. We also explore the possibilities and challenges of employing optogenetics technology in future therapeutic strategies for the treatment of spinal disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Chemokines in neuron-glial cell interaction and pathogenesis of neuropathic pain.

    Science.gov (United States)

    Zhang, Zhi-Jun; Jiang, Bao-Chun; Gao, Yong-Jing

    2017-09-01

    Neuropathic pain resulting from damage or dysfunction of the nervous system is a highly debilitating chronic pain state and is often resistant to currently available treatments. It has become clear that neuroinflammation, mainly mediated by proinflammatory cytokines and chemokines, plays an important role in the establishment and maintenance of neuropathic pain. Chemokines were originally identified as regulators of peripheral immune cell trafficking and were also expressed in neurons and glial cells in the central nervous system. In recent years, accumulating studies have revealed the expression, distribution and function of chemokines in the spinal cord under chronic pain conditions. In this review, we provide evidence showing that several chemokines are upregulated after peripheral nerve injury and contribute to the pathogenesis of neuropathic pain via different forms of neuron-glia interaction in the spinal cord. First, chemokine CX3CL1 is expressed in primary afferents and spinal neurons and induces microglial activation via its microglial receptor CX3CR1 (neuron-to-microglia signaling). Second, CCL2 and CXCL1 are expressed in spinal astrocytes and act on CCR2 and CXCR2 in spinal neurons to increase excitatory synaptic transmission (astrocyte-to-neuron signaling). Third, we recently identified that CXCL13 is highly upregulated in spinal neurons after spinal nerve ligation and induces spinal astrocyte activation via receptor CXCR5 (neuron-to-astrocyte signaling). Strategies that target chemokine-mediated neuron-glia interactions may lead to novel therapies for the treatment of neuropathic pain.

  12. Spinal tuberculosis.

    Science.gov (United States)

    Dunn, R N; Ben Husien, M

    2018-04-01

    Tuberculosis (TB) remains endemic in many parts of the developing world and is increasingly seen in the developed world due to migration. A total of 1.3 million people die annually from the disease. Spinal TB is the most common musculoskeletal manifestation, affecting about 1 to 2% of all cases of TB. The coexistence of HIV, which is endemic in some regions, adds to the burden and the complexity of management. This review discusses the epidemiology, clinical presentation, diagnosis, impact of HIV and both the medical and surgical options in the management of spinal TB. Cite this article: Bone Joint J 2018;100-B:425-31.

  13. Sphincter (ring muscle) gymnastics for spinal cord injured and spinal cord transected patients.

    Science.gov (United States)

    Yom-Tov, S

    2000-07-01

    Sphincter gymnastics seem to be able to recruit central pattern generators--networks of neurons that generate motor patterns--through peripheral rhythmic stimuli and to activate them without supraspinal signals. This physical therapy method is thus suitable for treating spinal cord injured and spinal cord transected patients, for it can reach below the injured segment and feed signals into the central nervous system, thus activating vital organs. This article presents some observations and discusses a possible mechanism.

  14. Spinal Cord Studies in the African Giant Rat (Cricetomys gambianus ...

    African Journals Online (AJOL)

    olayemitoyin

    Internal basilar nucleus. ICo9. Intercostals muscle motor neuron of lamina 9. IH9. Infrahyoid muscle motor neuron of lamina 9. IML. Intermediolateral column. IMM. Intermediomedial column. Lsg. Laminae of spinal gray matter. LatC. Lateral cervical nucleus. Lf. Lateral funiculus. LPrCb. Lumbar paracerebellar nucleus. Lsp.

  15. Spinal cord injury, dendritic spine remodeling, and spinal memory mechanisms.

    Science.gov (United States)

    Tan, Andrew M; Waxman, Stephen G

    2012-05-01

    Spinal cord injury (SCI) often results in the development of neuropathic pain, which can persist for months and years after injury. Although many aberrant changes to sensory processing contribute to the development of chronic pain, emerging evidence demonstrates that mechanisms similar to those underlying classical learning and memory can contribute to central sensitization, a phenomenon of amplified responsiveness to stimuli in nociceptive dorsal horn neurons. Notably, dendritic spines have emerged as major players in learning and memory, providing a structural substrate for how the nervous system modifies connections to form and store information. Until now, most information regarding dendritic spines has been obtained from studies in the brain. Recent experimental data in the spinal cord, however, demonstrate that Rac1-regulated dendritic spine remodeling occurs on second-order wide dynamic range neurons and accompanies neuropathic pain after SCI. Thus, SCI-induced synaptic potentiation engages a putative spinal memory mechanism. A compelling, novel possibility for pain research is that a synaptic model of long-term memory storage could explain the persistent nature of neuropathic pain. Such a conceptual bridge between pain and memory could guide the development of more effective strategies for treatment of chronic pain after injury to the nervous system. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Stress exacerbates neuron loss and microglia proliferation in a rat model of excitotoxic lower motor neuron injury.

    Science.gov (United States)

    Puga, Denise A; Tovar, C Amy; Guan, Zhen; Gensel, John C; Lyman, Matthew S; McTigue, Dana M; Popovich, Phillip G

    2015-10-01

    All individuals experience stress and hormones (e.g., glucocorticoids/GCs) released during stressful events can affect the structure and function of neurons. These effects of stress are best characterized for brain neurons; however, the mechanisms controlling the expression and binding affinity of glucocorticoid receptors in the spinal cord are different than those in the brain. Accordingly, whether stress exerts unique effects on spinal cord neurons, especially in the context of pathology, is unknown. Using a controlled model of focal excitotoxic lower motor neuron injury in rats, we examined the effects of acute or chronic variable stress on spinal cord motor neuron survival and glial activation. New data indicate that stress exacerbates excitotoxic spinal cord motor neuron loss and associated activation of microglia. In contrast, hypertrophy and hyperplasia of astrocytes and NG2+ glia were unaffected or were modestly suppressed by stress. Although excitotoxic lesions cause significant motor neuron loss and stress exacerbates this pathology, overt functional impairment did not develop in the relevant forelimb up to one week post-lesion. These data indicate that stress is a disease-modifying factor capable of altering neuron and glial responses to pathological challenges in the spinal cord. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Assessment of in vivo spinal cord conduction velocity in rats in an experimental model of ischemic spinal cord injury.

    Science.gov (United States)

    Basoglu, H; Kurtoglu, T; Cetin, N K; Bilgin, M D; Kiylioglu, N

    2013-08-01

    Experimental laboratory investigation of spinal cord conductivity alterations in a rat model of ischemic spinal cord injury (SCI). To observe the epidural spinal cord stimulation-induced electromyography responses, and to investigate the possible alterations of spinal cord conduction velocity (SCCV) and compound muscle action potentials (CMAPs) after ischemic SCI in rats. Adnan Menderes University, Institute of Health Science, Aydin, Turkey. SCI was induced by transient occlusion of the abdominal aorta in male Sprague-Dawley rats. Spinal cord histopathology was examined to determine neuronal damage and Tarlov scale was used to grade locomotor functions. Epidural electrical stimulation of spinal cord was performed by monopolar needle electrodes sequentially at L1-L2 and L5-L6 levels, and CMAPs were recorded from the left gastrocnemius muscle by surface electrodes. Amplitudes and durations of CMAPs were evaluated and SCCVs were calculated by analyzing the latency difference of CMAPs. Ischemia-induced SCI resulted in significant reduction of Tarlov scores and a significant decline in number of viable neurons. Similarly, a significant decrement was observed in SCCV following spinal cord ischemia. This study demonstrated that measurement of SCCV via epidural electrical stimulation is possible and displays a significant decline after spinal cord ischemia in rats. We suggest that this method can be beneficial to quantify neuronal damage after experimental ischemic SCI.

  18. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Spinal Cord Injury 101 ... arrow What is the “Spinal Cord Injury Model Systems” program? play_arrow What are the most promising ...

  19. Spinal Muscular Atrophy FAQ

    Science.gov (United States)

    ... SMA: Frequently Asked Questions What is Spinal Muscular Atrophy? Spinal Muscular Atrophy (SMA) is a genetic neuromuscular ... future trials in SMA. What is Spinal Muscular Atrophy with Respiratory Distress (SMARD)? SMARD and SMA are ...

  20. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Spinal Cord Injury 101 Adult Injuries Spinal Cord Injury 101 David ...

  1. Spinal Cord Injury 101

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    Full Text Available ... About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Spinal Cord Injury 101 Adult ... LLC Understanding Spinal Cord Injury About Us Expert Videos Contact Us Personal Experience Videos Blog Videos By ...

  2. Spinal Cord Injury 101

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    Full Text Available ... Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Spinal Cord Injury ... Jennifer Piatt, PhD David Chen, MD Read Bio Medical Director, Spinal Cord Injury Rehabilitation Program, Rehabilitation Institute ...

  3. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics menu Topics Spinal Cord Injury 101 Adult Injuries Spinal Cord Injury 101 ...

  4. Spinal Cord Diseases

    Science.gov (United States)

    Your spinal cord is a bundle of nerves that runs down the middle of your back. It carries signals back ... of the spine, this can also injure the spinal cord. Other spinal cord problems include Tumors Infections such ...

  5. Spinal Cord Injury 101

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    Full Text Available ... L Sarah Harrison, OT Anne Bryden, OT The Role of the Social Worker after Spinal Cord Injury ... a spinal cord injury important? play_arrow What role does “compression” play in a spinal cord injury? ...

  6. Spinal Cord Injury 101

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    Full Text Available ... spinal cord injury? play_arrow What kind of surgery is common after a spinal cord injury? play_ ... How soon after a spinal cord injury should surgery be performed? play_arrow Is it common to ...

  7. Spinal Cord Injury 101

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    Full Text Available ... Spinal Cord Injury Diane M. Rowles, MS, NP How Family Life Changes After Spinal Cord Injury Nancy ... Abuse and Spinal Cord Injury Allen Heinemann, PhD How Peer Counseling Works Julie Gassaway, MS, RN Pediatric ...

  8. Spinal Cord Injury 101

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    Full Text Available ... Spinal Cord Injury 101 Lawrence Vogel, MD The Basics of Pediatric SCI Rehabilitation Sara Klaas, MSW Transitions for Children with Spinal Cord Injury Patricia Mucia, RN Family Life After Pediatric Spinal Injury Dawn Sheaffer, MSW Rehabilitation ...

  9. Spinal Cord Injury 101

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    Full Text Available ... Cord Injury Diane M. Rowles, MS, NP How Family Life Changes After Spinal Cord Injury Nancy Rosenberg, ... Children with Spinal Cord Injury Patricia Mucia, RN Family Life After Pediatric Spinal Injury Dawn Sheaffer, MSW ...

  10. Spinal cord contusion.

    Science.gov (United States)

    Ju, Gong; Wang, Jian; Wang, Yazhou; Zhao, Xianghui

    2014-04-15

    Spinal cord injury is a major cause of disability with devastating neurological outcomes and limited therapeutic opportunities, even though there are thousands of publications on spinal cord injury annually. There are two major types of spinal cord injury, transaction of the spinal cord and spinal cord contusion. Both can theoretically be treated, but there is no well documented treatment in human being. As for spinal cord contusion, we have developed an operation with fabulous result.

  11. Transgenic tools to characterize neuronal properties of discrete populations of zebrafish neurons.

    Science.gov (United States)

    Satou, Chie; Kimura, Yukiko; Hirata, Hiromi; Suster, Maximiliano L; Kawakami, Koichi; Higashijima, Shin-ichi

    2013-09-01

    The developing nervous system consists of a variety of cell types. Transgenic animals expressing reporter genes in specific classes of neuronal cells are powerful tools for the study of neuronal network formation. We generated a wide variety of transgenic zebrafish that expressed reporter genes in specific classes of neurons or neuronal progenitors. These include lines in which neurons of specific neurotransmitter phenotypes expressed fluorescent proteins or Gal4, and lines in which specific subsets of the dorsal progenitor domain in the spinal cord expressed fluorescent proteins. Using these, we examined domain organization in the developing dorsal spinal cord, and found that there are six progenitor domains in zebrafish, which is similar to the domain organization in mice. We also systematically characterized neurotransmitter properties of the neurons that are produced from each domain. Given that reporter gene expressions occurs in a wide area of the nervous system in the lines generated, these transgenic fish should serve as powerful tools for the investigation of not only the neurons in the dorsal spinal cord but also neuronal structures and functions in many other regions of the nervous system.

  12. Spinal cord infarction; Spinaler Infarkt

    Energy Technology Data Exchange (ETDEWEB)

    Naumann, N.; Shariat, K.; Ulmer, S.; Stippich, C.; Ahlhelm, F.J. [Universitaetsspital Basel, Abteilung fuer Diagnostische und Interventionelle Neuroradiologie, Klinik fuer Radiologie und Nuklearmedizin, Basel (Switzerland)

    2012-05-15

    Infarction of the spinal cord can cause a variety of symptoms and neurological deficits because of the complex vascular supply of the myelon. The most common leading symptom is distal paresis ranging from paraparesis to tetraplegia caused by arterial ischemia or infarction of the myelon. Venous infarction, however, cannot always be distinguished from arterial infarction based on the symptoms alone. Modern imaging techniques, such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA) assist in preoperative planning of aortic operations to reliably identify not only the most important vascular structure supplying the spinal cord, the artery of Adamkiewicz, but also other pathologies such as tumors or infectious disorders. In contrast to CT, MRI can reliably depict infarction of the spinal cord. (orig.) [German] Die durch einen Rueckenmarkinfarkt verursachte Symptomatik kann aufgrund der komplexen Blutversorgung des Myelons zu unterschiedlichen neurologischen Ausfaellen fuehren. Dabei steht haeufig die durch eine arterielle Minderperfusion des Myelons bedingte Querschnittssymptomatik im Vordergrund. Venoes induzierte Mikrozirkulationsstoerungen sind anhand des neurologischen Befundes klinisch nicht immer von arteriellen Infarkten zu unterscheiden. Die moderne Bildgebung unter Einsatz der CT- (CTA) und MR-Angiographie (MRA) dient dem Ausschluss nichtvaskulaerer Ursachen fuer die Symptomatik wie Entzuendungen und Tumoren sowie der praeoperativen Planung vor der Aortenchirurgie zum Nachweis der fuer die Myelondurchblutung entscheidenden A. Adamkiewicz. Im Gegensatz zur CT kann mittels MRT ein Infarkt im Myelon mit hoher Verlaesslichkeit nachgewiesen werden. (orig.)

  13. Sleep disordered breathing in motor neurone disease

    OpenAIRE

    D’Cruz, Rebecca F.; Murphy, Patrick B.; Kaltsakas, Georgios

    2018-01-01

    Motor neurone disease (MND) is a neurodegenerative disease defined by axonal loss and gliosis of upper and lower motor neurones in the motor cortex, lower brainstem nuclei and ventral horn of the spinal cord. MND is currently incurable and has a poor prognosis, with death typically occurring 3 to 5 years after disease onset. The disease is characterised by rapidly progressive weakness leading to paralysis, fasciculations, bulbar symptoms (including dysarthria and dysphagia) and respiratory co...

  14. Heavy metals in locus ceruleus and motor neurons in motor neuron disease.

    Science.gov (United States)

    Pamphlett, Roger; Kum Jew, Stephen

    2013-12-12

    The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons.

  15. Heavy metals in locus ceruleus and motor neurons in motor neuron disease

    Science.gov (United States)

    2013-01-01

    Background The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Results Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Conclusions Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons. PMID:24330485

  16. The Protective Effect of Spinal Cord Stimulation Postconditioning Against Spinal Cord Ischemia/Reperfusion Injury in Rabbits.

    Science.gov (United States)

    Li, Huixian; Dong, Xiuhua; Jin, Mu; Cheng, Weiping

    2018-01-18

    Delayed paraplegia due to spinal cord ischemia/reperfusion injury (IRI) remains one of the most severe complications of thoracoabdominal aneurysm surgery, for which effective prevention and treatment is still lacking. The current study investigates whether spinal cord stimulation (SCS) postconditioning has neuroprotective effects against spinal cord IRI. Ninety-six New Zealand white male rabbits were randomly divided into four groups as follows: a sham group and three experimental groups (C group, 2 Hz group, and 50 Hz group) n = 24/group. Spinal cord ischemia was induced by transient infrarenal aortic balloon occlusion for 28 min, after which rabbits in group C underwent no additional intervention, while rabbits in the other two experimental groups underwent 2 Hz or 50 Hz epidural SCS for 30 min at the onset of reperfusion and then daily until sacrifice. Hind limb neurologic function of rabbits was assessed using Jacob scale. Lumbar spinal cords were harvested immediately after sacrifice for histological examination and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. The number of viable α-motor neurons in ventral horn was counted and TUNEL-positive rate of α-motor neurons was calculated. Spinal cord IRI was caused by transient infrarenal aorta occlusion for 28 min. Both 2 Hz and 50 Hz SCS postconditioning had neuroprotective effects, particularly the 2 Hz SCS postconditioning. Comparing to C group and 50 Hz group, rabbits in the 2 Hz group demonstrated better hind limb motor function and a lower rate of TUNEL-positive α-motor neuron after eight hours, one day, three days, and seven days of spinal cord reperfusion. More viable α-motor neurons were preserved after one and three days of spinal cord reperfusion in 2 Hz group rabbits than in C group and 50 Hz group rabbits. SCS postconditioning at 2 Hz protected the spinal cord from IRI. © 2018 International Neuromodulation Society.

  17. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Experiences by Topic Resources Peer Counseling Blog About Media Donate close search Understanding Spinal Cord Injury What is a Spinal Cord ... by Rona Talcott Website by Mobile Marketing LLC Understanding Spinal Cord Injury About ... By Topic Media Resources Donate to support families facing spinal cord ...

  18. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... OTR/L Sarah Harrison, OT Anne Bryden, OT The Role of the Social Worker after Spinal Cord Injury Patti Rogers, ... the spinal cord work? play_arrow Why is the level of a spinal cord injury important? play_arrow What role does “compression” play in a spinal cord injury? ...

  19. Mammalian motor neurons corelease glutamate and acetylcholine at central synapses

    DEFF Research Database (Denmark)

    Nishimaru, Hiroshi; Restrepo, Carlos Ernesto; Ryge, Jesper

    2005-01-01

    Motor neurons (MNs) are the principal neurons in the mammalian spinal cord whose activities cause muscles to contract. In addition to their peripheral axons, MNs have central collaterals that contact inhibitory Renshaw cells and other MNs. Since its original discovery > 60 years ago, it has been...

  20. Spinal antinflammatory action of Diclofenac.

    Science.gov (United States)

    Sandri, Alberto

    2016-06-01

    Diclofenac is a non-steroidal antinflammatory drug (NSAID) that finds indication in the treatment of debilitating pathologies characterized by chronic pain sustained by inflammation, such as in rheumatic disease (rheumatoid arthritis or osteoarthritis) or periarthritis, bursitis, tendonitis, myositis and sciatica. Its properties differentiate it from other NSAIDs. In fact, diclofenac's increased effect on spinal nociception and chronic neuro-inflammatory pain may be referred to: 1) its synergistic effects on peroxisome proliferator-activated receptor-γ (PPAR- γ) activation and prostaglandin synthesis inhibition (COX-2 inhibition); 2) its capacity of suppressing neuronal hyperexcitability through the blockage of neuronal K+ channels in a concentration-dependant manner; and 3) its facility to cross the blood-brain barrier.

  1. Distribution of Spinal Sensitization Evoked by Inflammatory Pain Using Local Spinal Cord Glucose Utilization Combined with 3H-Phorbol 12,13-Dibutyrate Binding in Rats

    OpenAIRE

    Seiko, Yasuda; Kozo, Ishikawa; Yoshihiro, Matsumoto; Toru, Ariyoshi; Hironori, Sasaki; Yuika, Ida; Yasutake, Iwanaga; Hae-Kyu, Kim; Osamu, Nakanishi; Toshizo, Ishikawa

    2013-01-01

    Aims. Hyperalgesia following tissue injury is induced by plasticity in neurotransmission. Few investigators have considered the ascending input which activates the superficial of spinal cord. The aim was to examine neurotransmission and nociceptive processing in the spinal cord after mustard-oil (MO) injection. Both in vitro and in vivo autoradiographs were employed for neuronal activity and transmission in discrete spinal cord regions using the 14C-2-deoxyglucose method and 3H-phorbol 12,13-...

  2. Spinal pain

    International Nuclear Information System (INIS)

    Izzo, R.; Popolizio, T.; D’Aprile, P.; Muto, M.

    2015-01-01

    Highlights: • Purpose of this review is to address the current concepts on the pathophysiology of discogenic, radicular, facet and dysfunctional spinal pain, focusing on the role of the imaging in the diagnostic setting, to potentially address a correct approach also to minimally invasive interventional techniques. • Special attention will be given to the discogenic pain, actually considered as the most frequent cause of chronic low back pain. • The correct distinction between referred pain and radicular pain contributes to give a more correct approach to spinal pain. • The pathogenesis of chronic pain renders this pain a true pathology requiring a specific management. - Abstract: The spinal pain, and expecially the low back pain (LBP), represents the second cause for a medical consultation in primary care setting and a leading cause of disability worldwide [1]. LBP is more often idiopathic. It has as most frequent cause the internal disc disruption (IDD) and is referred to as discogenic pain. IDD refers to annular fissures, disc collapse and mechanical failure, with no significant modification of external disc shape, with or without endplates changes. IDD is described as a separate clinical entity in respect to disc herniation, segmental instability and degenerative disc desease (DDD). The radicular pain has as most frequent causes a disc herniation and a canal stenosis. Both discogenic and radicular pain also have either a mechanical and an inflammatory genesis. For to be richly innervated, facet joints can be a direct source of pain, while for their degenerative changes cause compression of nerve roots in lateral recesses and in the neural foramina. Degenerative instability is a common and often misdiagnosed cause of axial and radicular pain, being also a frequent indication for surgery. Acute pain tends to extinguish along with its cause, but the setting of complex processes of peripheral and central sensitization may influence its evolution in chronic

  3. Spinal pain

    Energy Technology Data Exchange (ETDEWEB)

    Izzo, R., E-mail: roberto1766@interfree.it [Neuroradiology Department, A. Cardarelli Hospital, Naples (Italy); Popolizio, T., E-mail: t.popolizio1@gmail.com [Radiology Department, Casa Sollievo della Sofferenza Hospital, San Giovanni Rotondo (Fg) (Italy); D’Aprile, P., E-mail: paoladaprile@yahoo.it [Neuroradiology Department, San Paolo Hospital, Bari (Italy); Muto, M., E-mail: mutomar@tiscali.it [Neuroradiology Department, A. Cardarelli Hospital, Napoli (Italy)

    2015-05-15

    Highlights: • Purpose of this review is to address the current concepts on the pathophysiology of discogenic, radicular, facet and dysfunctional spinal pain, focusing on the role of the imaging in the diagnostic setting, to potentially address a correct approach also to minimally invasive interventional techniques. • Special attention will be given to the discogenic pain, actually considered as the most frequent cause of chronic low back pain. • The correct distinction between referred pain and radicular pain contributes to give a more correct approach to spinal pain. • The pathogenesis of chronic pain renders this pain a true pathology requiring a specific management. - Abstract: The spinal pain, and expecially the low back pain (LBP), represents the second cause for a medical consultation in primary care setting and a leading cause of disability worldwide [1]. LBP is more often idiopathic. It has as most frequent cause the internal disc disruption (IDD) and is referred to as discogenic pain. IDD refers to annular fissures, disc collapse and mechanical failure, with no significant modification of external disc shape, with or without endplates changes. IDD is described as a separate clinical entity in respect to disc herniation, segmental instability and degenerative disc desease (DDD). The radicular pain has as most frequent causes a disc herniation and a canal stenosis. Both discogenic and radicular pain also have either a mechanical and an inflammatory genesis. For to be richly innervated, facet joints can be a direct source of pain, while for their degenerative changes cause compression of nerve roots in lateral recesses and in the neural foramina. Degenerative instability is a common and often misdiagnosed cause of axial and radicular pain, being also a frequent indication for surgery. Acute pain tends to extinguish along with its cause, but the setting of complex processes of peripheral and central sensitization may influence its evolution in chronic

  4. The Isolation of Pure Populations of Neurons by Laser Capture Microdissection: Methods and Application in Neuroscience.

    Science.gov (United States)

    Morris, Renée; Mehta, Prachi

    2018-01-01

    In mammals, the central nervous system (CNS) is constituted of various cellular elements, posing a challenge to isolating specific cell types to investigate their expression profile. As a result, tissue homogenization is not amenable to analyses of motor neurons profiling as these represent less than 10% of the total spinal cord cell population. One way to tackle the problem of tissue heterogeneity and obtain meaningful genomic, proteomic, and transcriptomic profiling is to use laser capture microdissection technology (LCM). In this chapter, we describe protocols for the capture of isolated populations of motor neurons from spinal cord tissue sections and for downstream transcriptomic analysis of motor neurons with RT-PCR. We have also included a protocol for the immunological confirmation that the captured neurons are indeed motor neurons. Although focused on spinal cord motor neurons, these protocols can be easily optimized for the isolation of any CNS neurons.

  5. Spinal motoneurone distress during experimental allergic encephalomyelitis.

    Science.gov (United States)

    Giardino, L; Giuliani, A; Fernandez, M; Calzà, L

    2004-10-01

    The main pathophysiological feature characterizing multiple sclerosis (MS) is demyelination. However, the possibility of neural damage has recently been proposed as a mechanism in chronic disease. Experimental allergic encephalomyelitis (EAE) is the most widely used experimental model for MS. We investigated occurrences of microglial activation and astrocytosis in the spinal cord, choline acetyl-transferase (ChAT) and calcitonin gene-related peptide (CGRP) mRNA regulation in spinal motoneurones during EAE. EAE was induced in female Lewis rats by injecting guinea pig spinal cord tissue in complete Freund's adjuvant (CFA) to which heat-inactivated Mycobacterium had been added. Rats injected with CFA and uninjected rats were used as controls. ChAT and CGRP mRNAs were studied by in situ hybridization in the lumbar spinal cord and a computerized grain counting procedure was used for quantification. No differences in ChAT mRNA level were found between control and CFA-injected rats. ChAT mRNA level was strongly reduced in EAE 14 days after immunization and then recovered (29 days after immunization). CGRP mRNA increased 14 days after immunization, and then recovered to control level. Extensive long-lasting gliosis developed in the spinal cord and around motoneurones and a transient expression of p75LNGFR in motoneurones was also found. These data suggest that during EAE, gliosis induces distress in spinal cord neurones involving the synthesis enzyme for the main transmitter.

  6. Spinal stenosis

    International Nuclear Information System (INIS)

    Beale, S.; Pathria, M.N.; Ross, J.S.; Masaryk, T.J.; Modic, M.T.

    1988-01-01

    The authors studied 50 patients who had spinal stenosis by means of MR imaging. All patients had undergone myelography and CT. Thirty patients underwent surgery. MR imaging included T1-weighted spin echo sequences with repetition time = 600 msec, echo time = 20 (600/20) sagittal and axial sections 4 mm thick with 2 mm gap. T2-weighted 2,000/60 axial images were obtained on 14 patients. Examinations were retrospectively evaluated for central stenosis, lateral recess narrowing, and foraminal encroachment. Measurements of sagittal, interpedicular, interfacet, and recess dimensions were made at L3-5. On MR images, 20 patients had single-level and 30 had multiple-level stenosis. There was excellent agreement between modalities with central canal stenosis, but a discrepancy in six patients with bony foraminal stenosis. MR imaging was an accurate method for assessment of lumbar stenosis, but CT appears marginally better for detection of bony foraminal stenosis in certain cases

  7. Spinal infections

    Energy Technology Data Exchange (ETDEWEB)

    Tali, E. Turgut E-mail: turguttali@gazi.edu.tr

    2004-05-01

    Spinal infections can be thought of as a spectrum of disease comprising spondylitis, discitis, spondylodiscitis, pyogenic facet arthropathy, epidural infections, meningitis, polyradiculopathy and myelitis. Radiological evaluations have gained importance in the diagnosis, treatment planning, treatment and treatment monitoring of the spinal infections. Conventional radiographs are usually the initial imaging study. The sensitivity and specificity of the plain radiographs are very low. The sensitivity of CT is higher while it lacks of specificity. Conventional CT has played minor role for the diagnosis of early spondylitis and disc space infection and for follow-up, researches are going on the value of MDCT. MRI is as sensitive, specific and accurate as combined nuclear medicine studies and the method of choice for the spondylitis. Low signal areas of the vertebral body, loss of definition of the end plates and interruption of the cortical continuity, destruction of the cortical margins are typical on T1WI whereas high signal of affected areas of the vertebral body and disc is typical on T2WI. Contrast is mandatory and increases conspicuity, specificity, and observer confidence in the diagnosis and facilitates the treatment planning. Contrast enhancement is the earliest sign and pathognomonic in the acute inflammatory episode and even in the subtle infection then persists to a varying degree for several weeks or months. The outcome of the treatment is influenced by the type of infection and by the degree of neurologic compromise before treatment. There is an increasing move away from surgical intervention towards conservative therapy, percutaneous drainage of abscess or both. It is therefore critical to monitor treatment response, particularly in the immuno-deficient population.

  8. Noisy Neurons

    Indian Academy of Sciences (India)

    IAS Admin

    Nerves are fibres that conduct electrical signals and hence pass on information from and to the brain. Nerves are made of nerve cells called neurons (Figure 1). Instructions in our body are sent via electrical signals that present themselves as variations in the potential across neuronal membranes. These potential differences ...

  9. Neurons in red nucleus and primary motor cortex exhibit similar responses to mechanical perturbations applied to the upper-limb during posture

    Directory of Open Access Journals (Sweden)

    Troy Michael Herter

    2015-04-01

    Full Text Available Primary motor cortex (M1 and red nucleus (RN are brain regions involved in limb motor control. Both structures are highly interconnected with the cerebellum and project directly to the spinal cord, although the contribution of RN is smaller than M1. It remains uncertain whether RN and M1 serve similar or distinct roles during posture and movement. Many neurons in M1 respond rapidly to mechanical disturbances of the limb, but it remains unclear whether RN neurons also respond to such limb perturbations. We have compared discharges of single neurons in RN (n = 49 and M1 (n = 109 of one monkey during a postural perturbation task. Neural responses to whole-limb perturbations were examined by transiently applying (300 ms flexor or extensor torques to the shoulder and/or elbow while the monkeys attempted to maintain a static hand posture. Relative to baseline discharges before perturbation onset, perturbations evoked rapid (<100 ms changes of neural discharges in many RN (28 of 49, 57% and M1 (43 of 109, 39% neurons. In addition to exhibiting a greater proportion of perturbation-related neurons, RN neurons also tended to exhibit higher peak discharge frequencies in response to perturbations than M1 neurons. Importantly, neurons in both structures exhibited similar response latencies and tuning properties (preferred torque directions and tuning widths in joint-torque space. Proximal arm muscles also displayed similar tuning properties in joint-torque space. These results suggest that RN is more sensitive than M1 to mechanical perturbations applied during postural control but both structures may play a similar role in feedback control of posture.

  10. Responding to Misbehavior

    OpenAIRE

    Telep, Valya Goodwin, 1955-

    2009-01-01

    This series of lessons was prepared for parents like you - parents who want to do a better job of disciplining their children. The lessons were especially written for parents of preschool children, ages two to six, but some of the discipline methods are appropriate for older children, too. This lesson focuses on responding to misbehavior.

  11. Spinal and bulbar muscular atrophy.

    Science.gov (United States)

    Lieberman, Andrew P

    2018-01-01

    Spinal and bulbar muscular atrophy (SBMA) is an adult-onset degenerative disorder of the neuromuscular system resulting in slowly progressive weakness and atrophy of the proximal limb and bulbar muscles. The disease is caused by the expansion of a CAG/glutamine tract in the amino-terminus of the androgen receptor. That SBMA exclusively affects males reflects the fact that critical pathogenic events are hormone-dependent. These include translocation of the polyglutamine androgen receptor from the cytoplasm to the nucleus and unfolding of the mutant protein. Studies of the pathology of SBMA subjects have revealed nuclear aggregates of the mutant androgen receptor, loss of lower motor neurons in the brainstem and spinal cord, and both neurogenic and myopathic changes in skeletal muscle. Mechanisms underlying disease pathogenesis include toxicity in both lower motor neurons and skeletal muscle, where effects on transcription, intracellular transport, and mitochondrial function have been documented. Therapies to treat SBMA patients remain largely supportive, although experimental approaches targeting androgen action or promoting degradation of the mutant androgen receptor protein or the encoding RNA are under active study. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Thoracic rat spinal cord contusion injury induces remote spinal gliogenesis but not neurogenesis or gliogenesis in the brain.

    Directory of Open Access Journals (Sweden)

    Steffen Franz

    Full Text Available After spinal cord injury, transected axons fail to regenerate, yet significant, spontaneous functional improvement can be observed over time. Distinct central nervous system regions retain the capacity to generate new neurons and glia from an endogenous pool of progenitor cells and to compensate neural cell loss following certain lesions. The aim of the present study was to investigate whether endogenous cell replacement (neurogenesis or gliogenesis in the brain (subventricular zone, SVZ; corpus callosum, CC; hippocampus, HC; and motor cortex, MC or cervical spinal cord might represent a structural correlate for spontaneous locomotor recovery after a thoracic spinal cord injury. Adult Fischer 344 rats received severe contusion injuries (200 kDyn of the mid-thoracic spinal cord using an Infinite Horizon Impactor. Uninjured rats served as controls. From 4 to 14 days post-injury, both groups received injections of bromodeoxyuridine (BrdU to label dividing cells. Over the course of six weeks post-injury, spontaneous recovery of locomotor function occurred. Survival of newly generated cells was unaltered in the SVZ, HC, CC, and the MC. Neurogenesis, as determined by identification and quantification of doublecortin immunoreactive neuroblasts or BrdU/neuronal nuclear antigen double positive newly generated neurons, was not present in non-neurogenic regions (MC, CC, and cervical spinal cord and unaltered in neurogenic regions (dentate gyrus and SVZ of the brain. The lack of neuronal replacement in the brain and spinal cord after spinal cord injury precludes any relevance for spontaneous recovery of locomotor function. Gliogenesis was increased in the cervical spinal cord remote from the injury site, however, is unlikely to contribute to functional improvement.

  13. Somatostatin in the caudal spinal cord

    DEFF Research Database (Denmark)

    Schrøder, H D

    1984-01-01

    The distribution of somatostatin in the rat spinal cord was studied immunohistochemically with particular reference to the localization in the caudal centers that innervate the pelvic organs. For detailed studies of the laminar distribution of somatostatin the combination of immunohistochemistry...... and acetylcholinesterase enzyme histochemistry was employed. Deafferentation experiments were carried out to shed light on the origin of the somatostatin-containing axons. These experiments showed that the bulk of the spinal somatostatin has a spinal origin. The structures showing somatostatin immunoreactivity formed...... in the sacral parasympathetic intermediolateral nucleus. In contrast, very few appeared in the sympathetic nuclei. Immunoreactive somata were present in the surroundings of the central canal at all levels. Moreover, positive neurons were found in the intermediolateral nucleus of the sacral cord. By combined...

  14. The role of glia in the spinal cord in neuropathic and inflammatory pain.

    Science.gov (United States)

    Old, Elizabeth Amy; Clark, Anna K; Malcangio, Marzia

    2015-01-01

    Chronic pain, both inflammatory and neuropathic, is a debilitating condition in which the pain experience persists after the painful stimulus has resolved. The efficacy of current treatment strategies using opioids, NSAIDS and anticonvulsants is limited by the extensive side effects observed in patients, underlining the necessity for novel therapeutic targets. Preclinical models of chronic pain have recently provided evidence for a critical role played by glial cells in the mechanisms underlying the chronicity of pain, both at the site of damage in the periphery and in the dorsal horn of the spinal cord. Here microglia and astrocytes respond to the increased input from the periphery and change morphology, increase in number and release pro-nociceptive mediators such as ATP, cytokines and chemokines. These gliotransmitters can sensitise neurons by activation of their cognate receptors thereby contributing to central sensitization which is fundamental for the generation of allodynia, hyperalgesia and spontaneous pain.

  15. Partly shared spinal cord networks for locomotion and scratching.

    Science.gov (United States)

    Berkowitz, Ari; Hao, Zhao-Zhe

    2011-12-01

    Animals produce a variety of behaviors using a limited number of muscles and motor neurons. Rhythmic behaviors are often generated in basic form by networks of neurons within the central nervous system, or central pattern generators (CPGs). It is known from several invertebrates that different rhythmic behaviors involving the same muscles and motor neurons can be generated by a single CPG, multiple separate CPGs, or partly overlapping CPGs. Much less is known about how vertebrates generate multiple, rhythmic behaviors involving the same muscles. The spinal cord of limbed vertebrates contains CPGs for locomotion and multiple forms of scratching. We investigated the extent of sharing of CPGs for hind limb locomotion and for scratching. We used the spinal cord of adult red-eared turtles. Animals were immobilized to remove movement-related sensory feedback and were spinally transected to remove input from the brain. We took two approaches. First, we monitored individual spinal cord interneurons (i.e., neurons that are in between sensory neurons and motor neurons) during generation of each kind of rhythmic output of motor neurons (i.e., each motor pattern). Many spinal cord interneurons were rhythmically activated during the motor patterns for forward swimming and all three forms of scratching. Some of these scratch/swim interneurons had physiological and morphological properties consistent with their playing a role in the generation of motor patterns for all of these rhythmic behaviors. Other spinal cord interneurons, however, were rhythmically activated during scratching motor patterns but inhibited during swimming motor patterns. Thus, locomotion and scratching may be generated by partly shared spinal cord CPGs. Second, we delivered swim-evoking and scratch-evoking stimuli simultaneously and monitored the resulting motor patterns. Simultaneous stimulation could cause interactions of scratch inputs with subthreshold swim inputs to produce normal swimming, acceleration

  16. GDE2 regulates subtype-specific motor neuron generation through inhibition of Notch signaling.

    Science.gov (United States)

    Sabharwal, Priyanka; Lee, Changhee; Park, Sungjin; Rao, Meenakshi; Sockanathan, Shanthini

    2011-09-22

    The specification of spinal interneuron and motor neuron identities initiates within progenitor cells, while motor neuron subtype diversification is regulated by hierarchical transcriptional programs implemented postmitotically. Here we find that mice lacking GDE2, a six-transmembrane protein that triggers motor neuron generation, exhibit selective losses of distinct motor neuron subtypes, specifically in defined subsets of limb-innervating motor pools that correlate with the loss of force-generating alpha motor neurons. Mechanistically, GDE2 is expressed by postmitotic motor neurons but utilizes extracellular glycerophosphodiester phosphodiesterase activity to induce motor neuron generation by inhibiting Notch signaling in neighboring motor neuron progenitors. Thus, neuronal GDE2 controls motor neuron subtype diversity through a non-cell-autonomous feedback mechanism that directly regulates progenitor cell differentiation, implying that subtype specification initiates within motor neuron progenitor populations prior to their differentiation into postmitotic motor neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Spinal nociceptive circuit analysis with recombinant adeno-associated viruses: the impact of serotypes and promoters.

    Science.gov (United States)

    Haenraets, Karen; Foster, Edmund; Johannssen, Helge; Kandra, Vinnie; Frezel, Noémie; Steffen, Timothy; Jaramillo, Valeria; Paterna, Jean-Charles; Zeilhofer, Hanns Ulrich; Wildner, Hendrik

    2017-09-01

    Recombinant adeno-associated virus (rAAV) vector-mediated gene transfer into genetically defined neuron subtypes has become a powerful tool to study the neuroanatomy of neuronal circuits in the brain and to unravel their functions. More recently, this methodology has also become popular for the analysis of spinal cord circuits. To date, a variety of naturally occurring AAV serotypes and genetically modified capsid variants are available but transduction efficiency in spinal neurons, target selectivity, and the ability for retrograde tracing are only incompletely characterized. Here, we have compared the transduction efficiency of seven commonly used AAV serotypes after intraspinal injection. We specifically analyzed local transduction of different types of dorsal horn neurons, and retrograde transduction of dorsal root ganglia (DRG) neurons and of neurons in the rostral ventromedial medulla (RVM) and the somatosensory cortex (S1). Our results show that most of the tested rAAV vectors have similar transduction efficiency in spinal neurons. All serotypes analyzed were also able to transduce DRG neurons and descending RVM and S1 neurons via their spinal axon terminals. When comparing the commonly used rAAV serotypes to the recently developed serotype 2 capsid variant rAAV2retro, a > 20-fold increase in transduction efficiency of descending supraspinal neurons was observed. Conversely, transgene expression in retrogradely transduced neurons was strongly reduced when the human synapsin 1 (hSyn1) promoter was used instead of the strong ubiquitous hybrid cytomegalovirus enhancer/chicken β-actin promoter (CAG) or cytomegalovirus (CMV) promoter fragments. We conclude that the use of AAV2retro greatly increases transduction of neurons connected to the spinal cord via their axon terminals, while the hSyn1 promoter can be used to minimize transgene expression in retrogradely connected neurons of the DRG or brainstem. Cover Image for this issue: doi. 10.1111/jnc.13813.

  18. A progressive compression model of thoracic spinal cord injury in mice: function assessment and pathological changes in spinal cord

    Directory of Open Access Journals (Sweden)

    Guo-dong Sun

    2017-01-01

    Full Text Available Non-traumatic injury accounts for approximately half of clinical spinal cord injury, including chronic spinal cord compression. However, previous rodent spinal cord compression models are mainly designed for rats, few are available for mice. Our aim is to develop a thoracic progressive compression mice model of spinal cord injury. In this study, adult wild-type C57BL/6 mice were divided into two groups: in the surgery group, a screw was inserted at T9 lamina to compress the spinal cord, and the compression was increased by turning it further into the canal (0.2 mm post-surgery every 2 weeks up to 8 weeks. In the control group, a hole was drilled into the lamina without inserting a screw. The results showed that Basso Mouse Scale scores were lower and gait worsened. In addition, the degree of hindlimb dysfunction in mice was consistent with the degree of spinal cord compression. The number of motor neurons in the anterior horn of the spinal cord was reduced in all groups of mice, whereas astrocytes and microglia were gradually activated and proliferated. In conclusion, this progressive compression of thoracic spinal cord injury in mice is a preferable model for chronic progressive spinal cord compression injury.

  19. Intermittent hypoxia induces functional recovery following cervical spinal injury.

    Science.gov (United States)

    Vinit, Stéphane; Lovett-Barr, Mary Rachael; Mitchell, Gordon S

    2009-11-30

    Respiratory-related complications are the leading cause of death in spinal cord injury (SCI) patients. Few effective SCI treatments are available after therapeutic interventions are performed in the period shortly after injury (e.g. spine stabilization and prevention of further spinal damage). In this review we explore the capacity to harness endogenous spinal plasticity induced by intermittent hypoxia to optimize function of surviving (spared) neural pathways associated with breathing. Two primary questions are addressed: (1) does intermittent hypoxia induce plasticity in spinal synaptic pathways to respiratory motor neurons following experimental SCI? and (2) can this plasticity improve respiratory function? In normal rats, intermittent hypoxia induces serotonin-dependent plasticity in spinal pathways to respiratory motor neurons. Early experiments suggest that intermittent hypoxia also enhances respiratory motor output in experimental models of cervical SCI (cervical hemisection) and that the capacity to induce functional recovery is greater with longer durations post-injury. Available evidence suggests that intermittent hypoxia-induced spinal plasticity has considerable therapeutic potential to treat respiratory insufficiency following chronic cervical spinal injury.

  20. Spinal Cord Dysfunction (SCD)

    Data.gov (United States)

    Department of Veterans Affairs — The Spinal Cord Dysfunction (SCD) module supports the maintenance of local and national registries for the tracking of patients with spinal cord injury and disease...

  1. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... SCI Personal Experiences by Topic Resources Peer Counseling Blog About Media Donate close search Understanding Spinal Cord ... SCI Personal Experiences by Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert ...

  2. Spinal Cord Injury 101

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    Full Text Available ... with SCI Personal Experiences by Topic Resources Peer Counseling Blog About Media Donate close search Understanding Spinal ... with SCI Personal Experiences by Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical ...

  3. Spinal Cord Injury 101

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    Full Text Available ... Resources Peer Counseling Blog About Media Donate close search Understanding Spinal Cord Injury What is a Spinal ... health care products or services, or control the information found on external websites. The Hill Foundation is ...

  4. Spinal Cord Injury 101

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    Full Text Available ... of Spinal Cord Injury Rehabilitation Kristine Cichowski, MS Occupational Therapy after Spinal Cord Injury Katie Powell, OT ... does not provide medical advice, recommend or endorse health care products or services, or control the information ...

  5. Spinal Cord Injury 101

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    Full Text Available ... spinal cord injuries? play_arrow What does stem-cell research on animals tell us? play_arrow When can we expect stem-cell treatments to become available for spinal cord injuries? ...

  6. Spinal Cord Injury 101

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    Full Text Available ... Spinal Cord Injuries Video Library SCI Medical Experts People Living with SCI Personal Experiences by Topic Resources ... Spinal Cord Injuries Video Library SCI Medical Experts People Living with SCI Personal Experiences by Topic Resources ...

  7. Spinal Cord Injury 101

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    Full Text Available ... Cord Injury Rehabilitation Pediatric Spinal Cord Injuries Video Library SCI Medical Experts People Living with SCI Personal ... Cord Injury Rehabilitation Pediatric Spinal Cord Injuries Video Library SCI Medical Experts People Living with SCI Personal ...

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    Full Text Available ... Disabilities Photography by Rona Talcott Website by Mobile Marketing LLC Understanding Spinal Cord Injury About Us Expert Videos Contact Us Personal Experience Videos Blog Videos By Topic Media Resources Donate to support families facing spinal cord ...

  9. Spinal cord stimulation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007560.htm Spinal cord stimulation To use the sharing features on this page, please enable JavaScript. Spinal cord stimulation is a treatment for pain that uses ...

  10. Spinal Cord Injury 101

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    Full Text Available ... Experiences by Topic Resources Peer Counseling Blog About Media Donate close search Understanding Spinal Cord Injury What ... Experiences by Topic Resources Peer Counseling Blog About Media Donate Spinal Cord Injury Medical Expert Videos Topics ...

  11. Spinal Cord Injury 101

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    Full Text Available ... RN Pediatric Injuries Pediatric Spinal Cord Injury 101 Lawrence Vogel, MD The Basics of Pediatric SCI Rehabilitation ... Rogers, PT Recreational Therapy after Spinal Cord Injury Jennifer Piatt, PhD David Chen, MD Read Bio Medical ...

  12. Spinal Cord Injury 101

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    Full Text Available ... program? play_arrow What are the most promising new treatments for spinal cord injuries? play_arrow What are the latest developments in the use of electrical stimulation for spinal ...

  13. Spinal Cord Injury 101

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    Full Text Available ... electrical stimulation for spinal cord injuries? play_arrow What is “Braingate” research? play_arrow How would stem-cell therapies work in the treatment of spinal cord injuries? play_ ...

  14. Spinal Cord Injury 101

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    Full Text Available ... spinal cord injuries. The website does not provide medical advice, recommend or endorse health care products or services, ... spinal cord injuries. The website does not provide medical advice, recommend or endorse health care products or services, ...

  15. The Mirror Neuron System and Action Recognition

    Science.gov (United States)

    Buccino, Giovanni; Binkofski, Ferdinand; Riggio, Lucia

    2004-01-01

    Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been…

  16. Axon and dendrite geography predict the specificity of synaptic connections in a functioning spinal cord network

    Directory of Open Access Journals (Sweden)

    Borisyuk Roman

    2007-09-01

    Full Text Available Abstract Background How specific are the synaptic connections formed as neuronal networks develop and can simple rules account for the formation of functioning circuits? These questions are assessed in the spinal circuits controlling swimming in hatchling frog tadpoles. This is possible because detailed information is now available on the identity and synaptic connections of the main types of neuron. Results The probabilities of synapses between 7 types of identified spinal neuron were measured directly by making electrical recordings from 500 pairs of neurons. For the same neuron types, the dorso-ventral distributions of axons and dendrites were measured and then used to calculate the probabilities that axons would encounter particular dendrites and so potentially form synaptic connections. Surprisingly, synapses were found between all types of neuron but contact probabilities could be predicted simply by the anatomical overlap of their axons and dendrites. These results suggested that synapse formation may not require axons to recognise specific, correct dendrites. To test the plausibility of simpler hypotheses, we first made computational models that were able to generate longitudinal axon growth paths and reproduce the axon distribution patterns and synaptic contact probabilities found in the spinal cord. To test if probabilistic rules could produce functioning spinal networks, we then made realistic computational models of spinal cord neurons, giving them established cell-specific properties and connecting them into networks using the contact probabilities we had determined. A majority of these networks produced robust swimming activity. Conclusion Simple factors such as morphogen gradients controlling dorso-ventral soma, dendrite and axon positions may sufficiently constrain the synaptic connections made between different types of neuron as the spinal cord first develops and allow functional networks to form. Our analysis implies that

  17. Distribution of Spinal Sensitization Evoked by Inflammatory Pain Using Local Spinal Cord Glucose Utilization Combined with (3) H-Phorbol 12,13-Dibutyrate Binding in Rats.

    Science.gov (United States)

    Seiko, Yasuda; Kozo, Ishikawa; Yoshihiro, Matsumoto; Toru, Ariyoshi; Hironori, Sasaki; Yuika, Ida; Yasutake, Iwanaga; Hae-Kyu, Kim; Osamu, Nakanishi; Toshizo, Ishikawa

    2013-01-01

    Aims. Hyperalgesia following tissue injury is induced by plasticity in neurotransmission. Few investigators have considered the ascending input which activates the superficial of spinal cord. The aim was to examine neurotransmission and nociceptive processing in the spinal cord after mustard-oil (MO) injection. Both in vitro and in vivo autoradiographs were employed for neuronal activity and transmission in discrete spinal cord regions using the (14)C-2-deoxyglucose method and (3)H-phorbol 12,13-dibutyrate ((3)H-PDBu) binding sites. Methods. To quantify the hyperalgesia evoked by MO, the flinching was counted for 60 min after MO (20%, 50 μL) injection in Wistar rats. Simultaneous determination of (14)C-2-deoxyglucose and (3)H-PDBu binding was used for a direct observation of neuronal/metabolic changes and intracellular signaling in the spinal cord. Results. MO injection evoked an increase in flinching for 60 min. LSCGU significantly increased in the Rexed I-II with (3)H-PDBu binding in the ipsilateral side of spinal cord. Discussion. We clearly demonstrated that the hyperalgesia is primarily relevant to increased neuronal activation with PKC activation in the Rexed I-II of the spinal cord. In addition, functional changes such as "neuronal plasticity" may result in increased neuronal excitability and a central sensitization.

  18. Supraspinal modulation of neuronal synchronization by nociceptive stimulation induces an enduring reorganization of dorsal horn neuronal connectivity.

    Science.gov (United States)

    Contreras-Hernández, E; Chávez, D; Hernández, E; Velázquez, E; Reyes, P; Béjar, J; Martín, M; Cortés, U; Glusman, S; Rudomin, P

    2018-02-16

    The state of central sensitization induced by the intradermic injection of capsaicin leads to structured (non-random) changes in functional connectivity between dorsal horn neuronal populations distributed along the spinal lumbar segments in anaesthetized cats. The capsaicin-induced changes in neuronal connectivity and the concurrent increase in secondary hyperalgesia are transiently reversed by the systemic administration of small doses of lidocaine, a clinically effective procedure to treat neuropathic pain. The effects of both capsaicin and lidocaine are greatly attenuated in spinalized preparations, showing that supraspinal influences play a significant role in the shaping of nociceptive-induced changes in dorsal horn functional neuronal connectivity. We conclude that changes in functional connectivity between segmental populations of dorsal horn neurones induced by capsaicin and lidocaine result from a cooperative adaptive interaction between supraspinal and spinal neuronal networks, a process that may have a relevant role in the pathogenesis of chronic pain and analgesia. Despite a profusion of information on the molecular and cellular mechanisms involved in the central sensitization produced by intense nociceptive stimulation, the changes in the patterns of functional connectivity between spinal neurones associated with the development of secondary hyperalgesia and allodynia remain largely unknown. Here we show that the state of central sensitization produced by the intradermal injection of capsaicin is associated with structured transformations in neuronal synchronization that lead to an enduring reorganization of the functional connectivity within a segmentally distributed ensemble of dorsal horn neurones. These changes are transiently reversed by the systemic administration of small doses of lidocaine, a clinically effective procedure to treat neuropathic pain. Lidocaine also reduces the capsaicin-induced facilitation of the spinal responses evoked by

  19. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... injury? play_arrow How does the spinal cord work? play_arrow Why is the level of a spinal cord injury important? play_arrow What role does “compression” play in a spinal cord injury? play_arrow Why are high-dose steroids often used right after an injury? play_arrow What is meant ...

  20. Spinal Cord Injury

    Science.gov (United States)

    ... Types of illnesses and disabilities Spinal cord injury Spinal cord injury Read advice from Dr. Jeffrey Rabin , a pediatric ... your health on a daily basis. Living with spinal cord injury — your questions answered top What are pediatric ...

  1. Spinal Cord Injuries

    Science.gov (United States)

    ... forth between your body and your brain. A spinal cord injury disrupts the signals. Spinal cord injuries usually begin with a blow that fractures or ... down on the nerve parts that carry signals. Spinal cord injuries can be complete or incomplete. With a complete ...

  2. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Cord Injury Diane M. Rowles, MS, NP How Family Life Changes After Spinal Cord Injury Nancy Rosenberg, PsyD ... Children with Spinal Cord Injury Patricia Mucia, RN Family Life After Pediatric Spinal Injury Dawn Sheaffer, MSW Rehabilitation ...

  3. Synchronization of motor neurons during locomotion in the neonatal rat

    DEFF Research Database (Denmark)

    Tresch, Matthew C.; Kiehn, Ole

    2002-01-01

    We describe here the robust synchronization of motor neurons at a millisecond time scale during locomotor activity in the neonatal rat. Action potential activity of motor neuron pairs was recorded extracellularly using tetrodes during locomotor activity in the in vitro neonatal rat spinal cord. A...... synchronization described here might be involved in activity-dependent processes during development or in the coordination of individual motor neurons into a functional population underlying behavior.......We describe here the robust synchronization of motor neurons at a millisecond time scale during locomotor activity in the neonatal rat. Action potential activity of motor neuron pairs was recorded extracellularly using tetrodes during locomotor activity in the in vitro neonatal rat spinal cord....... Approximately 40% of motor neuron pairs recorded in the same spinal segment showed significant synchronization, with the duration of the central peak in cross-correlograms between motor neurons typically ranging between ∼ 30 and 100 msec. The percentage of synchronized motor neuron pairs was considerably higher...

  4. Schwann cells for spinal cord repair

    Directory of Open Access Journals (Sweden)

    M. Oudega

    2005-06-01

    Full Text Available The complex nature of spinal cord injury appears to demand a multifactorial repair strategy. One of the components that will likely be included is an implant that will fill the area of lost nervous tissue and provide a growth substrate for injured axons. Here we will discuss the role of Schwann cells (SCs in cell-based, surgical repair strategies of the injured adult spinal cord. We will review key studies that showed that intraspinal SC grafts limit injury-induced tissue loss and promote axonal regeneration and myelination, and that this response can be improved by adding neurotrophic factors or anti-inflammatory agents. These results will be compared with several other approaches to the repair of the spinal cord. A general concern with repair strategies is the limited functional recovery, which is in large part due to the failure of axons to grow across the scar tissue at the distal graft-spinal cord interface. Consequently, new synaptic connections with spinal neurons involved in motor function are not formed. We will highlight repair approaches that did result in growth across the scar and discuss the necessity for more studies involving larger, clinically relevant types of injuries, addressing this specific issue. Finally, this review will reflect on the prospect of SCs for repair strategies in the clinic.

  5. Synaptic defects in the spinal and neuromuscular circuitry in a mouse model of spinal muscular atrophy.

    Directory of Open Access Journals (Sweden)

    Karen K Y Ling

    2010-11-01

    Full Text Available Spinal muscular atrophy (SMA is a major genetic cause of death in childhood characterized by marked muscle weakness. To investigate mechanisms underlying motor impairment in SMA, we examined the spinal and neuromuscular circuitry governing hindlimb ambulatory behavior in SMA model mice (SMNΔ7. In the neuromuscular circuitry, we found that nearly all neuromuscular junctions (NMJs in hindlimb muscles of SMNΔ7 mice remained fully innervated at the disease end stage and were capable of eliciting muscle contraction, despite a modest reduction in quantal content. In the spinal circuitry, we observed a ∼28% loss of synapses onto spinal motoneurons in the lateral column of lumbar segments 3-5, and a significant reduction in proprioceptive sensory neurons, which may contribute to the 50% reduction in vesicular glutamate transporter 1(VGLUT1-positive synapses onto SMNΔ7 motoneurons. In addition, there was an increase in the association of activated microglia with SMNΔ7 motoneurons. Together, our results present a novel concept that synaptic defects occur at multiple levels of the spinal and neuromuscular circuitry in SMNΔ7 mice, and that proprioceptive spinal synapses could be a potential target for SMA therapy.

  6. Ablation of the Ferroptosis Inhibitor Glutathione Peroxidase 4 in Neurons Results in Rapid Motor Neuron Degeneration and Paralysis*

    Science.gov (United States)

    Chen, Liuji; Hambright, William Sealy; Na, Ren; Ran, Qitao

    2015-01-01

    Glutathione peroxidase 4 (GPX4), an antioxidant defense enzyme active in repairing oxidative damage to lipids, is a key inhibitor of ferroptosis, a non-apoptotic form of cell death involving lipid reactive oxygen species. Here we show that GPX4 is essential for motor neuron health and survival in vivo. Conditional ablation of Gpx4 in neurons of adult mice resulted in rapid onset and progression of paralysis and death. Pathological inspection revealed that the paralyzed mice had a dramatic degeneration of motor neurons in the spinal cord but had no overt neuron degeneration in the cerebral cortex. Consistent with the role of GPX4 as a ferroptosis inhibitor, spinal motor neuron degeneration induced by Gpx4 ablation exhibited features of ferroptosis, including no caspase-3 activation, no TUNEL staining, activation of ERKs, and elevated spinal inflammation. Supplementation with vitamin E, another inhibitor of ferroptosis, delayed the onset of paralysis and death induced by Gpx4 ablation. Also, lipid peroxidation and mitochondrial dysfunction appeared to be involved in ferroptosis of motor neurons induced by Gpx4 ablation. Taken together, the dramatic motor neuron degeneration and paralysis induced by Gpx4 ablation suggest that ferroptosis inhibition by GPX4 is essential for motor neuron health and survival in vivo. PMID:26400084

  7. Ablation of the Ferroptosis Inhibitor Glutathione Peroxidase 4 in Neurons Results in Rapid Motor Neuron Degeneration and Paralysis.

    Science.gov (United States)

    Chen, Liuji; Hambright, William Sealy; Na, Ren; Ran, Qitao

    2015-11-20

    Glutathione peroxidase 4 (GPX4), an antioxidant defense enzyme active in repairing oxidative damage to lipids, is a key inhibitor of ferroptosis, a non-apoptotic form of cell death involving lipid reactive oxygen species. Here we show that GPX4 is essential for motor neuron health and survival in vivo. Conditional ablation of Gpx4 in neurons of adult mice resulted in rapid onset and progression of paralysis and death. Pathological inspection revealed that the paralyzed mice had a dramatic degeneration of motor neurons in the spinal cord but had no overt neuron degeneration in the cerebral cortex. Consistent with the role of GPX4 as a ferroptosis inhibitor, spinal motor neuron degeneration induced by Gpx4 ablation exhibited features of ferroptosis, including no caspase-3 activation, no TUNEL staining, activation of ERKs, and elevated spinal inflammation. Supplementation with vitamin E, another inhibitor of ferroptosis, delayed the onset of paralysis and death induced by Gpx4 ablation. Also, lipid peroxidation and mitochondrial dysfunction appeared to be involved in ferroptosis of motor neurons induced by Gpx4 ablation. Taken together, the dramatic motor neuron degeneration and paralysis induced by Gpx4 ablation suggest that ferroptosis inhibition by GPX4 is essential for motor neuron health and survival in vivo. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Spinal cord stimulation therapy for localized central pain

    International Nuclear Information System (INIS)

    Hirato, Masafumi; Takahashi, Akio; Watanabe, Katsushige; Kazama, Ken; Yoshimoto, Yuhei

    2008-01-01

    We studied the pathophysiology of localized central pain and the surgical result of spinal cord stimulation. There were 10 cases; 7 males and 3 females from 24 to 77 years old. Pain was caused by peripheral nerve injury in one case, spinal cord injury in two cases and cerebrovascular disease (CVD) (thalamic pain) in 7 cases. All cases were treated by epidural spinal cord stimulation and followed from 0.8 to 8.8 years. Sufficient pain relief was achieved in one case of peripheral nerve and spinal cord injury and in 4 cases of CVD. Moderate pain control was achieved in 2 cases of CVD. In one each case of spinal cord injury and of CVD, pain control was ineffective. In cases with thalamic pain, we studied the correlation between the surgical result of spinal cord stimulation and the clinical features, MRI, fluoro-deoxyglucose (FDG)-positron emission tomography (PET), and somatosensory evoked potentials (SEP) findings before operation. MRI revealed a small to moderate sized lesion on the thalamus or putamen in each case. PET also showed decreased accumulation of FDG on the affected thalamus. In all cases without one fair responder to spinal cord stimulation, we could recognize definite SEP originating in the sensory cortex ipsilateral side to the CVD lesion during contralateral median or posterior tibial nerve stimulation. In the good responders, we could recognize SEP originating in the sensory cortex of the lesion side with less delayed latency or decreased amplitude than in the moderate responders. In this group, test stimulation with low voltage on the spinal cord evoked a sensory effect (paresthesia) over the painful part of the body. Spinal cord stimulation proved to be an effective treatment for localized central pain. In cases with localized central pain after CVD, we could expect to ameliorate the intractable pain in those cases in which SEP or spinal cord test stimulation revealed that the thalamo-cortical system was preserved. (author)

  9. Trauma: Spinal Cord Injury.

    Science.gov (United States)

    Eckert, Matthew J; Martin, Matthew J

    2017-10-01

    Injuries to the spinal column and spinal cord frequently occur after high-energy mechanisms of injury, or with lower-energy mechanisms, in select patient populations like the elderly. A focused yet complete neurologic examination during the initial evaluation will guide subsequent diagnostic procedures and early supportive measures to help prevent further injury. For patients with injury to bone and/or ligaments, the initial focus should be spinal immobilization and prevention of inducing injury to the spinal cord. Spinal cord injury is associated with numerous life-threatening complications during the acute and long-term phases of care that all acute care surgeons must recognize. Published by Elsevier Inc.

  10. International Spinal Cord Injury

    DEFF Research Database (Denmark)

    Dvorak, M F; Itshayek, E; Fehlings, M G

    2015-01-01

    STUDY DESIGN: Survey of expert opinion, feedback and final consensus. OBJECTIVE: To describe the development and the variables included in the International Spinal Cord Injury (SCI) Spinal Interventions and Surgical Procedures Basic Data set. SETTING: International working group. METHODS......: A committee of experts was established to select and define data elements. The data set was then disseminated to the appropriate committees and organizations for comments. All suggested revisions were considered and both the International Spinal Cord Society and the American Spinal Injury Association endorsed...... spinal intervention and procedure is coded (variables 1 through 7) and the spinal segment level is described (variables 8 and 9). Sample clinical cases were developed to illustrate how to complete it. CONCLUSION: The International SCI Spinal Interventions and Surgical Procedures Basic Data Set...

  11. Diabetes does not accelerate neuronal loss following nerve injury

    DEFF Research Database (Denmark)

    Severinsen, Kaare; Jakobsen, Johannes

    2007-01-01

    To determine the resistance of neuronal dorsal root ganglion (DRG) cells in experimental diabetes, we studied the neuronal cell loss after severe axonal injury in streptozotocin (STZ) diabetic rats with unilateral transection of the L5 spinal nerve for 12 weeks. Fifty 18-week-old inbred male Wistar...... rats were randomly allocated to three study groups. In study group 1 without spinal nerve injury, STZ diabetes was induced in 9 and 10 rats were kept as nondiabetic controls. In study group 2, spinal nerve injury was performed in 10 diabetic rats and in 10 nondiabetic controls. In study group 3, six...... nondiabetic control rats at 18 weeks and five nondiabetic control rats at 30 weeks were included to determine whether DRG cell changes occur without nerve injury during the study period. In group 1, the stereologically determined number of all neuronal DRG cells was unchanged after 12 weeks of diabetes...

  12. DELTAMETHRIN AND PERMETHRIN DECREASE SPONTANEOUS ACTIVITY IN NEURONAL NETWORKS IN VITRO.

    Science.gov (United States)

    Effects of pyrethroid insecticides on spontaneous electrical activity were investigated in primary cultures of cortical or spinal cord neurons grown on microelectrode arrays. Bicuculline (40 ¿M) was utilized to block fast GABAergic transmission, and concentration-dependent effect...

  13. The Hypocretin/Orexin Neuronal Networks in Zebrafish.

    Science.gov (United States)

    Elbaz, Idan; Levitas-Djerbi, Talia; Appelbaum, Lior

    2017-01-01

    The hypothalamic Hypocretin/Orexin (Hcrt) neurons secrete two Hcrt neuropeptides. These neurons and peptides play a major role in the regulation of feeding, sleep wake cycle, reward-seeking, addiction, and stress. Loss of Hcrt neurons causes the sleep disorder narcolepsy. The zebrafish has become an attractive model to study the Hcrt neuronal network because it is a transparent vertebrate that enables simple genetic manipulation, imaging of the structure and function of neuronal circuits in live animals, and high-throughput monitoring of behavioral performance during both day and night. The zebrafish Hcrt network comprises ~16-60 neurons, which similar to mammals, are located in the hypothalamus and widely innervate the brain and spinal cord, and regulate various fundamental behaviors such as feeding, sleep, and wakefulness. Here we review how the zebrafish contributes to the study of the Hcrt neuronal system molecularly, anatomically, physiologically, and pathologically.

  14. LINKAGE MAPPING OF THE SPINAL MUSCULAR-ATROPHY GENE

    NARCIS (Netherlands)

    BURGHES, AHM; INGRAHAM, SE; KOTEJARAI, Z; ROSENFELD, S; HERTA, N; NADKARNI, N; DIDONATO, CJ; CARPTEN, J; HURKO, O; FLORENCE, J; MOXLEY, RT; COBBEN, JM; MENDELL, [No Value

    Spinal muscular atrophy (SMA) is a common autosomal recessive disorder resulting in loss of motor neurons. We have performed linkage analysis on a panel of families using nine markers that are closely linked to the SMA gene. The highest lod score was obtained with the marker D5S351 (Z(max) = 10.04

  15. Development of rat embryonic spinal ganglion cells in damaged nerve.

    Science.gov (United States)

    Petrova, E S; Isaeva, E N; Korzhevskii, D E

    2014-09-01

    The development of dissociated cells from rat embryonic spinal ganglion after transplantation to damaged nerve of adult animals was studied using immunohistochemical differentiation markers of neural and glial cells. The cell suspension obtained after dissociation of rat embryonic spinal ganglia (embryonic day 15) was injected into the proximal segment of crushed sciatic nerve. The nerve was damaged by ligation for 40 sec. Progenitor cells were labeled with 5-bromo-2'-deoxyuridine (BrdU) before transplantation. BrdU-immunopositive cells were detected in the nerve trunks of recipients on days 1, 21, and 28 after transplantation. Dissociated cells of rat embryonic spinal ganglion (embryonic day 15) survived for at least 4 weeks after transplantation to the nerve and differentiate into NeuN-immunopositive neurons with morphological properties of sensory neurons and satellite cells containing S100 protein.

  16. Noisy Neurons

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 1. Noisy Neurons: Hodgkin-Huxley Model and Stochastic Variants. Shurti Paranjape. General Article Volume 20 Issue 1 January 2015 pp 34-43. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. Reaction to topical capsaicin in spinal cord injury patients with and without central pain

    DEFF Research Database (Denmark)

    Finnerup, Nanna Brix; Pedersen, Louise H.; Terkelsen, Astrid J.

    2007-01-01

    of a spinal cord injury which already is hyperexcitable, would cause enhanced responses in patients with central pain at the level of injury compared to patients without neuropathic pain and healthy controls. Touch, punctuate stimuli, cold stimuli and topical capsaicin was applied above, at, and below injury......Central neuropathic pain is a debilitating and frequent complication to spinal cord injury (SCI). Excitatory input from hyperexcitable cells around the injured grey matter zone is suggested to play a role for central neuropathic pain felt below the level of a spinal cord injury. Direct evidence...... at the level of injury. Keywords: Spinal cord injury; Neuropathic pain; Capsaicin; Neuronal hyperexcitability; Hyperalgesia; Blood flow...

  18. Mirror neurons: Enigma of the metaphysical modular brain.

    Science.gov (United States)

    Acharya, Sourya; Shukla, Samarth

    2012-07-01

    Mirror neurons are one of the most important discoveries in the last decade of neuroscience. These are a variety of visuospatial neurons which indicate fundamentally about human social interaction. Essentially, mirror neurons respond to actions that we observe in others. The interesting part is that mirror neurons fire in the same way when we actually recreate that action ourselves. Apart from imitation, they are responsible for myriad of other sophisticated human behavior and thought processes. Defects in the mirror neuron system are being linked to disorders like autism. This review is a brief introduction to the neurons that shaped our civilization.

  19. Modeling the neuroanatomic propagation of ALS in the spinal cord

    Science.gov (United States)

    Drawert, Brian; Thakore, Nimish; Mitchell, Brian; Pioro, Erik; Ravits, John; Petzold, Linda R.

    2017-07-01

    Recent hypotheses of amyotrophic lateral sclerosis (ALS) progression have posited a point-source origin of motor neuron death with neuroanatomic propagation either contiguously to adjacent regions, or along networks via axonal and synaptic connections. Although the molecular mechanisms of propagation are unknown, one leading hypothesis is a "prion-like" spread of misfolded and aggregated proteins, including SOD1 and TDP-43. We have developed a mathematical model representing cellular and molecular spread of ALS in the human spinal cord. Our model is based on the stochastic reaction-diffusion master equation approach using a tetrahedral discretized space to capture the complex geometry of the spinal cord. Domain dimension and shape was obtained by reconstructing human spinal cord from high-resolution magnetic resonance (MR) images and known gross and histological neuroanatomy. Our preliminary results qualitatively recapitulate the clinically observed pattern of spread of ALS thorough the spinal cord.

  20. Development and regulation of response properties in spinal cord motoneurons

    DEFF Research Database (Denmark)

    Perrier, J F; Hounsgaard, J

    2000-01-01

    The intrinsic response properties of spinal motoneurons determine how converging premotor neuronal input is translated into the final motor command transmitted to muscles. From the patchy data available it seems that these properties and their underlying currents are highly conserved in terrestrial...... vertebrates in terms of both phylogeny and ontogeny. Spinal motoneurons in adults are remarkably similar in many respects ranging from the resting membrane potential to pacemaker properties. Apart from the axolotls, spinal motoneurons from all species investigated have latent intrinsic response properties...... mediated by L-type Ca2+ channels. This mature phenotype is reached gradually during development through phases in which A-type potassium channels and T-type calcium channels are transiently expressed. The intrinsic response properties of mature spinal motoneurons are subject to short-term adjustments via...

  1. The Brain Is Needed to Cure Spinal Cord Injury.

    Science.gov (United States)

    Isa, Tadashi

    2017-10-01

    Damage to corticospinal fibers in the cervical spinal cord is known to impair dexterous hand movements. However, accumulating evidence has shown that precision grip can recover considerably through rehabilitative training. Recent multidisciplinary studies have revealed that, at the spinal level, this recovery is possible due to an indirect neural pathway through propriospinal neurons (PNs), which relay cortical commands to hand motoneurons. Although this indirect spinal pathway is heavily involved in recovery, its role is dwarfed by a simultaneous large-scale network reorganization spanning motor-related cortices and mesolimbic structures. This large-scale network reorganization is key to the regulation of recovery and future therapeutic strategies will need to take into account the involvement of these supraspinal centers in addition to the known role of the spinal cord. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Calcium signals in olfactory neurons.

    Science.gov (United States)

    Tareilus, E; Noé, J; Breer, H

    1995-11-09

    Laser scanning confocal microscopy in combination with the fluorescent calcium indicators Fluo-3 and Fura-Red was employed to estimate the intracellular concentration of free calcium ions in individual olfactory receptor neurons and to monitor temporal and spatial changes in the Ca(2+)-level upon stimulation. The chemosensory cells responded to odorants with a significant increase in the calcium concentration, preferentially in the dendritic knob. Applying various stimulation paradigma, it was found that in a population of isolated cells, subsets of receptor neurons display distinct patterns of responsiveness.

  3. Neurogenesis in spinal cord of mouse: an autoradiographic analysis

    International Nuclear Information System (INIS)

    Nornes, H.O.; Carry, M.

    1978-01-01

    An autoradiographic analysis of the time and sites of origin, and the migration and setting patterns of neurons was made in the spinal cord of the mouse. The neurons originated on days 10-15 of gestation with temporal gradients along the ventrodorsal and rostrocaudal axes. The motor neurons originated on days 10-11 of gestation; the neurons in the intermediate gray region originated on days 11-14 of gestation; the neurons of the head of the dorsal horn originated on days 12-14 of gestation. The neurons that originated on days 10 and 11 originated and migrated primarily from the basal plate, and they settled in the adjacent regions of the intermediate zone; those neurons formed on days 12-14 originated and migrated primarily from the alar plate, and it was concluded that these neuroblasts similarly settled in the adjacent regions of the intermediate zone. Extraventricular proliferation, which presumably signaled the initial stages of gliogenesis, was first observed on day 12 of gestation. This study supports the classical idea of the mosaic pattern of neurogenesis in the embryonic spinal cord. (Auth.)

  4. Overview of Spinal Cord Disorders

    Science.gov (United States)

    ... Is the Spinal Cord Damaged? The spine (spinal column) contains the spinal cord, which is divided into four sections: Cervical (neck) Thoracic (chest) Lumbar (lower back) Sacral (pelvis). Each section is referred ...

  5. Inhibition of myostatin does not ameliorate disease features of severe spinal muscular atrophy mice

    OpenAIRE

    Sumner, Charlotte J.; Wee, Claribel D.; Warsing, Leigh C.; Choe, Dong W.; Ng, Andrew S.; Lutz, Cathleen; Wagner, Kathryn R.

    2009-01-01

    There is currently no treatment for the inherited motor neuron disease, spinal muscular atrophy (SMA). Severe SMA causes lower motor neuron loss, impaired myofiber development, profound muscle weakness and early mortality. Myostatin is a transforming growth factor-β family member that inhibits muscle growth. Loss or blockade of myostatin signaling increases muscle mass and improves muscle strength in mouse models of primary muscle disease and in the motor neuron disease, amyotrophic lateral s...

  6. MULTIPLE SPINAL CANAL MENINGIOMAS

    Directory of Open Access Journals (Sweden)

    Nandigama Pratap Kumar

    2016-10-01

    Full Text Available BACKGROUND Meningiomas of the spinal canal are common tumours with the incidence of 25 percent of all spinal cord tumours. But multiple spinal canal meningiomas are rare in compare to solitary lesions and account for 2 to 3.5% of all spinal meningiomas. Most of the reported cases are both intra cranial and spinal. Exclusive involvement of the spinal canal by multiple meningiomas are very rare. We could find only sixteen cases in the literature to the best of our knowledge. Exclusive multiple spinal canal meningiomas occurring in the first two decades of life are seldom reported in the literature. We are presenting a case of multiple spinal canal meningiomas in a young patient of 17 years, who was earlier operated for single lesion. We analysed the literature, with illustration of our case. MATERIALS AND METHODS In September 2016, we performed a literature search for multiple spinal canal meningiomas involving exclusively the spinal canal with no limitation for language and publication date. The search was conducted through http://pubmed.com, a wellknown worldwide internet medical address. To the best of our knowledge, we could find only sixteen cases of multiple meningiomas exclusively confined to the spinal canal. Exclusive multiple spinal canal meningiomas occurring in the first two decades of life are seldom reported in the literature. We are presenting a case of multiple spinal canal meningiomas in a young patient of 17 years, who was earlier operated for solitary intradural extra medullary spinal canal meningioma at D4-D6 level, again presented with spastic quadriparesis of two years duration and MRI whole spine demonstrated multiple intradural extra medullary lesions, which were excised completely and the histopathological diagnosis was transitional meningioma. RESULTS Patient recovered from his weakness and sensory symptoms gradually and bladder and bowel symptoms improved gradually over a period of two to three weeks. CONCLUSION Multiple

  7. Spinal injury in sport

    Energy Technology Data Exchange (ETDEWEB)

    Barile, Antonio [Department of Radiology, University of L' Aquila, S. Salvatore Hospital, Via Vetoio, Coppito, 67100 L' Aquila (Italy)]. E-mail: antonio.barile@cc.univaq.it; Limbucci, Nicola [Department of Radiology, University of L' Aquila, S. Salvatore Hospital, Via Vetoio, Coppito, 67100 L' Aquila (Italy); Splendiani, Alessandra [Department of Radiology, University of L' Aquila, S. Salvatore Hospital, Via Vetoio, Coppito, 67100 L' Aquila (Italy); Gallucci, Massimo [Department of Radiology, University of L' Aquila, S. Salvatore Hospital, Via Vetoio, Coppito, 67100 L' Aquila (Italy); Masciocchi, Carlo [Department of Radiology, University of L' Aquila, S. Salvatore Hospital, Via Vetoio, Coppito, 67100 L' Aquila (Italy)

    2007-04-15

    Spinal injuries are very common among professional or amateur athletes. Spinal sport lesions can be classified in overuse and acute injuries. Overuse injuries can be found after years of repetitive spinal load during sport activity; however specific overuse injuries can also be found in adolescents. Acute traumas are common in contact sports. Most of the acute injuries are minor and self-healing, but severe and catastrophic events are possible. The aim of this article is to review the wide spectrum of spinal injuries related to sport activity, with special regard to imaging finding.

  8. Spinal injury in sport

    International Nuclear Information System (INIS)

    Barile, Antonio; Limbucci, Nicola; Splendiani, Alessandra; Gallucci, Massimo; Masciocchi, Carlo

    2007-01-01

    Spinal injuries are very common among professional or amateur athletes. Spinal sport lesions can be classified in overuse and acute injuries. Overuse injuries can be found after years of repetitive spinal load during sport activity; however specific overuse injuries can also be found in adolescents. Acute traumas are common in contact sports. Most of the acute injuries are minor and self-healing, but severe and catastrophic events are possible. The aim of this article is to review the wide spectrum of spinal injuries related to sport activity, with special regard to imaging finding

  9. Human spinal motor control

    DEFF Research Database (Denmark)

    Nielsen, Jens Bo

    2016-01-01

    interneurons and exert a direct (willful) muscle control with the aid of a context-dependent integration of somatosensory and visual information at cortical level. However, spinal networks also play an important role. Sensory feedback through spinal circuitries is integrated with central motor commands...... the central motor command by opening or closing sensory feedback pathways. In the future, human studies of spinal motor control, in close collaboration with animal studies on the molecular biology of the spinal cord, will continue to document the neural basis for human behavior. Expected final online...

  10. The safe spinal anaesthetic

    African Journals Online (AJOL)

    anticoagulation. Refusal. Severe hypovolaemia or shock. Localised sepsis .... Side-effects and complications of spinal anaesthesia. Side-effect/complication. Mechanism. Treatment. Hypotension. Sympathetic block causes vasodilatation.

  11. Feasibility of boron neutron capture therapy for malignant spinal tumors

    International Nuclear Information System (INIS)

    Nakai, Kei; Kumada, Hiroaki; Yamamoto, Tetsuya; Tsurubuchi, Takao; Zaboronok, Alexander; Matsumura, Akira

    2009-01-01

    Treatment of malignant spinal cord tumors is currently ineffective. The characteristics of the spine are its seriality, small volume, and vulnerability: severe QOL impairment can be brought about by small neuronal damage. The present study aimed to investigate the feasibility of BNCT as a tumor-selective charged particle therapy for spinal cord tumors from the viewpoint of protecting the normal spine. A previous report suggested the tolerance dose of the spinal cord was 13.8 Gy-Eq for radiation myelopathy; a dose as high as 11 Gy-Eq demonstrated no spinal cord damage in an experimental animal model. We calculated the tumor dose and the normal spinal cord dose on a virtual model of a spinal cord tumor patient with a JAEA computational dosimetry system (JCDS) treatment planning system. The present study made use of boronophenylalanine (BPA). In these calculations, conditions were set as follows: tumor/normal (T/N) ratio of 3.5, blood boron concentration of 12 ppm, tumor boron concentration of 42 ppm, and relative biological effectiveness (RBE) values for tumor and normal spinal cord of 3.8 and 1.35, respectively. We examined how to optimize neutron irradiation by changing the beam direction and number. In our theoretical example, simple opposed two-field irradiation achieved 28.0 Gy-Eq as a minimum tumor dose and 7.3 Gy-Eq as a maximum normal spinal dose. The BNCT for the spinal cord tumor was therefore feasible when a sufficient T/N ratio could be achieved. The use of F-BPA PET imaging for spinal tumor patients is supported by this study.

  12. Synchronization properties of heterogeneous neuronal networks with mixed excitability type.

    Science.gov (United States)

    Leone, Michael J; Schurter, Brandon N; Letson, Benjamin; Booth, Victoria; Zochowski, Michal; Fink, Christian G

    2015-03-01

    We study the synchronization of neuronal networks with dynamical heterogeneity, showing that network structures with the same propensity for synchronization (as quantified by master stability function analysis) may develop dramatically different synchronization properties when heterogeneity is introduced with respect to neuronal excitability type. Specifically, we investigate networks composed of neurons with different types of phase response curves (PRCs), which characterize how oscillating neurons respond to excitatory perturbations. Neurons exhibiting type 1 PRC respond exclusively with phase advances, while neurons exhibiting type 2 PRC respond with either phase delays or phase advances, depending on when the perturbation occurs. We find that Watts-Strogatz small world networks transition to synchronization gradually as the proportion of type 2 neurons increases, whereas scale-free networks may transition gradually or rapidly, depending upon local correlations between node degree and excitability type. Random placement of type 2 neurons results in gradual transition to synchronization, whereas placement of type 2 neurons as hubs leads to a much more rapid transition, showing that type 2 hub cells easily "hijack" neuronal networks to synchronization. These results underscore the fact that the degree of synchronization observed in neuronal networks is determined by a complex interplay between network structure and the dynamical properties of individual neurons, indicating that efforts to recover structural connectivity from dynamical correlations must in general take both factors into account.

  13. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... properties of this facility in the path from synaptic sites to the motor axon is reviewed with emphasis on voltage sensitive ion channels and regulatory metabotropic transmitter pathways. The catalog of the intrinsic response properties, their underlying mechanisms, and regulation obtained from motoneurons...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  14. Granulocyte-colony-stimulating factor (G-CSF) signaling in spinal microglia drives visceral sensitization following colitis.

    Science.gov (United States)

    Basso, Lilian; Lapointe, Tamia K; Iftinca, Mircea; Marsters, Candace; Hollenberg, Morley D; Kurrasch, Deborah M; Altier, Christophe

    2017-10-17

    Pain is a main symptom of inflammatory diseases and often persists beyond clinical remission. Although we have a good understanding of the mechanisms of sensitization at the periphery during inflammation, little is known about the mediators that drive central sensitization. Recent reports have identified hematopoietic colony-stimulating factors as important regulators of tumor- and nerve injury-associated pain. Using a mouse model of colitis, we identify the proinflammatory cytokine granulocyte-colony-stimulating factor (G-CSF or Csf-3) as a key mediator of visceral sensitization. We report that G-CSF is specifically up-regulated in the thoracolumbar spinal cord of colitis-affected mice. Our results show that resident spinal microglia express the G-CSF receptor and that G-CSF signaling mediates microglial activation following colitis. Furthermore, healthy mice subjected to intrathecal injection of G-CSF exhibit pronounced visceral hypersensitivity, an effect that is abolished by microglial depletion. Mechanistically, we demonstrate that G-CSF injection increases Cathepsin S activity in spinal cord tissues. When cocultured with microglia BV-2 cells exposed to G-CSF, dorsal root ganglion (DRG) nociceptors become hyperexcitable. Blocking CX3CR1 or nitric oxide production during G-CSF treatment reduces excitability and G-CSF-induced visceral pain in vivo. Finally, administration of G-CSF-neutralizing antibody can prevent the establishment of persistent visceral pain postcolitis. Overall, our work uncovers a DRG neuron-microglia interaction that responds to G-CSF by engaging Cathepsin S-CX3CR1-inducible NOS signaling. This interaction represents a central step in visceral sensitization following colonic inflammation, thereby identifying spinal G-CSF as a target for treating chronic abdominal pain.

  15. Transcutaneous spinal stimulation as a therapeutic strategy for spinal cord injury: state of the art

    Directory of Open Access Journals (Sweden)

    Grecco LH

    2015-03-01

    plasticity. We also developed a finite element method (FEM model to predict current flow in the spinal cord when using different electrode montages. We identified gaps in our knowledge of noninvasive electrical stimulation in the modulation of spinal neuronal networks in patients with SCI. tsDCS, TENS, and NMES have a positive influence on the promotion of plasticity in SCI. Although there are no randomized controlled studies of tsDCS in SCI, preliminary evidence is encouraging. FEMs predict that tsDCS electrode montage can be used to shape which spinal segments are modulated and what detailed areas of spinal anatomy can concentrate current density (eg, spinal roots. tsDCS is a technique that can influence conduction along ascending tracts in the spinal cord, so could modulate supraspinal activity. It may also be a promising new approach for a number of neuropsychiatric conditions.Keywords: spinal cord injury, transcutaneous spinal direct current stimulation, transcutaneous electric nerve stimulation, neuromuscular electrical stimulation, motor, spasticity, pain

  16. Neurotoxic effects of levobupivacaine and fentanyl on rat spinal cord

    Directory of Open Access Journals (Sweden)

    Yesim Cokay Abut

    2015-02-01

    Full Text Available BACKGROUND: The purpose of the study was to compare the neurotoxic effects of intrathecally administered levobupivacaine, fentanyl and their mixture on rat spinal cord. METHODS: In experiment, there were four groups with medication and a control group. Rats were injected 15 µL saline or fentanyl 0.0005 µg/15 µL, levobupivacaine 0.25%/15 µL and fentanyl 0.0005 µg + levobupivacaine 0.25%/15 µL intrathecally for four days. Hot plate test was performed to assess neurologic function after each injection at 5th, 30th and 60th min. Five days after last lumbal injection, spinal cord sections between the T5 and T6 vertebral levels were obtained for histologic analysis. A score based on subjective assessment of number of eosinophilic neurons - Red neuron - which means irreversible neuronal degeneration. They reflect the approximate number of degenerating neurons present in the affected neuroanatomic areas as follows: 1, none; 2, 1-20%; 3, 21-40%; 4, 41-60%; and 5, 61-100% dead neurons. An overall neuropathologic score was calculated for each rat by summating the pathologic scores for all spinal cord areas examined. RESULTS: In the results of HPT, comparing the control group, analgesic latency statistically prolonged for all four groups.In neuropathologic investment, the fentanyl and fentanyl + levobupivacaine groups have statistically significant high degenerative neuron counts than control and saline groups. CONCLUSIONS: These results suggest that, when administered intrathecally in rats, fentanyl and levobupivacaine behave similar for analgesic action, but fentanyl may be neurotoxic for spinal cord. There was no significant degeneration with levobupivacaine, but fentanyl group has had significant degeneration.

  17. Probing spinal circuits controlling walking in mammals

    DEFF Research Database (Denmark)

    Kiehn, Ole; Dougherty, Kimberly J.; Hägglund, Martin

    2010-01-01

    to neuroscientists. However, experiments using the isolated rodent spinal cord and combining electrophysiology and molecular genetics to dissect the locomotor network have started to shed new light on the network structure. In the present review, we will discuss findings that have revealed the role of designated......Locomotion in mammals is a complex motor act that involves the activation of a large number of muscles in a well-coordinated pattern. Understanding the network organization of the intrinsic spinal networks that control the locomotion, the central pattern generators, has been a challenge...... populations of neurons for the key network functions including coordinating muscle activity and generating rhythmic activity. These findings are summarized in proposed organizational principles for the mammalian segmental CPG....

  18. Reconstruction of phrenic neuron identity in embryonic stem cell-derived motor neurons.

    Science.gov (United States)

    Machado, Carolina Barcellos; Kanning, Kevin C; Kreis, Patricia; Stevenson, Danielle; Crossley, Martin; Nowak, Magdalena; Iacovino, Michelina; Kyba, Michael; Chambers, David; Blanc, Eric; Lieberam, Ivo

    2014-02-01

    Air breathing is an essential motor function for vertebrates living on land. The rhythm that drives breathing is generated within the central nervous system and relayed via specialised subsets of spinal motor neurons to muscles that regulate lung volume. In mammals, a key respiratory muscle is the diaphragm, which is innervated by motor neurons in the phrenic nucleus. Remarkably, relatively little is known about how this crucial subtype of motor neuron is generated during embryogenesis. Here, we used direct differentiation of motor neurons from mouse embryonic stem cells as a tool to identify genes that direct phrenic neuron identity. We find that three determinants, Pou3f1, Hoxa5 and Notch, act in combination to promote a phrenic neuron molecular identity. We show that Notch signalling induces Pou3f1 in developing motor neurons in vitro and in vivo. This suggests that the phrenic neuron lineage is established through a local source of Notch ligand at mid-cervical levels. Furthermore, we find that the cadherins Pcdh10, which is regulated by Pou3f1 and Hoxa5, and Cdh10, which is controlled by Pou3f1, are both mediators of like-like clustering of motor neuron cell bodies. This specific Pcdh10/Cdh10 activity might provide the means by which phrenic neurons are assembled into a distinct nucleus. Our study provides a framework for understanding how phrenic neuron identity is conferred and will help to generate this rare and inaccessible yet vital neuronal subtype directly from pluripotent stem cells, thus facilitating subsequent functional investigations.

  19. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Read Bio Medical Director, Spinal Cord Injury Rehabilitation Program, Rehabilitation Institute of Chicago play_arrow What is ... What is the “Spinal Cord Injury Model Systems” program? play_arrow What are the most promising new ...

  20. Spinal pain in adolescents

    DEFF Research Database (Denmark)

    Aartun, Ellen; Hartvigsen, Jan; Wedderkopp, Niels

    2014-01-01

    BACKGROUND: The severity and course of spinal pain is poorly understood in adolescents. The study aimed to determine the prevalence and two-year incidence, as well as the course, frequency, and intensity of pain in the neck, mid back, and low back (spinal pain). METHODS: This study was a school...

  1. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Heather Taylor, PhD Michelle Meade, PhD Jonathon Rose, PhD The Basics of Spinal Cord Injury Rehabilitation Kristine Cichowski, ... Cord Injury Katie Powell, OT Mary Jane Mulcahey, PhD, OTR/L Sarah Harrison, OT Anne Bryden, OT The Role of the Social Worker after Spinal Cord ...

  2. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... in a Wheelchair Lisa Rosen, MS Spasticity, Physical Therapy-Lokomat T. George Hornby, PhD, PT Empowering the Patient After Spinal Cord Injury Guy W. Fried, MD Substance Abuse and Spinal Cord Injury Allen Heinemann, PhD How ...

  3. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Cord Injury Allen Heinemann, PhD How Peer Counseling Works Julie Gassaway, MS, RN Pediatric Injuries Pediatric Spinal ... injury? play_arrow How does the spinal cord work? play_arrow Why is the level of a ...

  4. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... Spinal Cord Injury 101 Lawrence Vogel, MD The Basics of Pediatric SCI Rehabilitation Sara Klaas, MSW Transitions ... PhD Michelle Meade, PhD Jonathon Rose, PhD The Basics of Spinal Cord Injury Rehabilitation Kristine Cichowski, MS ...

  5. Spinal Cord Injury 101

    Medline Plus

    Full Text Available ... from Hospital to Home Kim Eberhardt Muir, MS Coping with a New Injury Robin Dorman, PsyD Sex and Fertility After Spinal Cord Injury Diane M. Rowles, MS, NP How Family Life Changes After Spinal Cord Injury Nancy Rosenberg, ...

  6. Humero-spinal dysostosis.

    Science.gov (United States)

    Cortina, H; Vidal, J; Vallcanera, A; Alberto, C; Muro, D; Dominguez, F

    1979-07-24

    A 2 year old boy with humero-spinal dysostosis is described. This is the third case of this disease reported in the literature. Humero-spinal dysostosis is characterised radiologically by distal humeral bifurcation, elbow subluxation and coronal cleft vertebrae. Congenital, progressive heart disease, possibly with fatal outcome, is probably part of the syndrome.

  7. Lower motor neuron involvement examined by quantitative electromyography in amyotrophic lateral sclerosis

    DEFF Research Database (Denmark)

    Krarup, Christian

    2011-01-01

    Objective The diagnosis of amyotrophic lateral sclerosis (ALS) includes demonstration of lower motor neuron (LMN) and upper motor neuron (UMN) involvement of bulbar and spinal muscles. Electromyography (EMG) is essential to confirm LMN affection in weak muscles, and to demonstrate changes...

  8. Cognitive dysfunction in lower motor neuron disease: executive and memory deficits in progressive muscular atrophy

    NARCIS (Netherlands)

    Raaphorst, J.; de Visser, M.; van Tol, M.-J.; Linssen, W.H.J.P.; van der Kooi, A.J.; de Haan, R.J.; van den Berg, L.H.; Schmand, B.

    2011-01-01

    Aim In contrast with findings in amyotrophic lateral sclerosis (ALS), cognitive impairments have as yet not been shown in the lower motor neuron variant of motor neuron disease, progressive spinal muscular atrophy (PMA). The objective of this study was to investigate cognitive function in PMA and to

  9. Axotomy depletes intracellular calcium stores in primary sensory neurons.

    Science.gov (United States)

    Rigaud, Marcel; Gemes, Geza; Weyker, Paul D; Cruikshank, James M; Kawano, Takashi; Wu, Hsiang-En; Hogan, Quinn H

    2009-08-01

    The cellular mechanisms of neuropathic pain are inadequately understood. Previous investigations have revealed disrupted Ca signaling in primary sensory neurons after injury. The authors examined the effect of injury on intracellular Ca stores of the endoplasmic reticulum, which critically regulate the Ca signal and neuronal function. Intracellular Ca levels were measured with Fura-2 or mag-Fura-2 microfluorometry in axotomized fifth lumbar (L5) dorsal root ganglion neurons and adjacent L4 neurons isolated from hyperalgesic rats after L5 spinal nerve ligation, compared to neurons from control animals. Endoplasmic reticulum Ca stores released by the ryanodine-receptor agonist caffeine decreased by 46% in axotomized small neurons. This effect persisted in Ca-free bath solution, which removes the contribution of store-operated membrane Ca channels, and after blockade of the mitochondrial, sarco-endoplasmic Ca-ATPase and the plasma membrane Ca ATPase pathways. Ca released by the sarco-endoplasmic Ca-ATPase blocker thapsigargin and by the Ca-ionophore ionomycin was also diminished by 25% and 41%, respectively. In contrast to control neurons, Ca stores in axotomized neurons were not expanded by neuronal activation by K depolarization, and the proportionate rate of refilling by sarco-endoplasmic Ca-ATPase was normal. Luminal Ca concentration was also reduced by 38% in axotomized neurons in permeabilized neurons. The adjacent neurons of the L4 dorsal root ganglia showed modest and inconsistent changes after L5 spinal nerve ligation. Painful nerve injury leads to diminished releasable endoplasmic reticulum Ca stores and a reduced luminal Ca concentration. Depletion of Ca stores may contribute to the pathogenesis of neuropathic pain.

  10. Age-Related Uptake of Heavy Metals in Human Spinal Interneurons.

    Science.gov (United States)

    Pamphlett, Roger; Kum Jew, Stephen

    2016-01-01

    Toxic heavy metals have been implicated in the loss of spinal motoneurons in amyotrophic lateral sclerosis/motor neuron disease (ALS/MND). Motoneuron loss in the spinal anterior horn is severe in ALS/MND at the time of death, making this tissue unsuitable for examination. We therefore examined spinal cords of people without muscle weakness to look for any presence of heavy metals that could make these neurons susceptible to damage. Spinal cord samples from 50 individuals aged 1-95 y who had no clinical or histopathological evidence of spinal motoneuron loss were studied. Seven μm formalin-fixed paraffin-embedded sections were stained for heavy metals with silver nitrate autometallography (AMGHM) which detects intracellular mercury, silver or bismuth. Neurons in the spinal cord were classified as interneurons or α-motoneurons based on their site and cell body diameter. Spinal interneurons containing heavy metals were present in 8 of 24 people (33%) aged 61-95 y, but not at younger ages. These AMGHM interneurons were most numerous in the lumbar spinal cord, with moderate numbers in the caudal cervical cord, few in the rostral cervical cord, and almost none in the thoracic cord. All people with AMGHM interneurons had occasional AMGHM staining in α-motoneurons as well. In one man AMGHM staining was present in addition in dorsomedial nucleus and sensory neurons. In conclusion, heavy metals are present in many spinal interneurons, and in a few α-motoneurons, in a large proportion of older people. Damage to inhibitory interneurons from toxic metals in later life could result in excitotoxic injury to motoneurons and may underlie motoneuron injury or loss in conditions such as ALS/MND, multiple sclerosis, sarcopenia and calf fasciculations.

  11. Age-Related Uptake of Heavy Metals in Human Spinal Interneurons.

    Directory of Open Access Journals (Sweden)

    Roger Pamphlett

    Full Text Available Toxic heavy metals have been implicated in the loss of spinal motoneurons in amyotrophic lateral sclerosis/motor neuron disease (ALS/MND. Motoneuron loss in the spinal anterior horn is severe in ALS/MND at the time of death, making this tissue unsuitable for examination. We therefore examined spinal cords of people without muscle weakness to look for any presence of heavy metals that could make these neurons susceptible to damage. Spinal cord samples from 50 individuals aged 1-95 y who had no clinical or histopathological evidence of spinal motoneuron loss were studied. Seven μm formalin-fixed paraffin-embedded sections were stained for heavy metals with silver nitrate autometallography (AMGHM which detects intracellular mercury, silver or bismuth. Neurons in the spinal cord were classified as interneurons or α-motoneurons based on their site and cell body diameter. Spinal interneurons containing heavy metals were present in 8 of 24 people (33% aged 61-95 y, but not at younger ages. These AMGHM interneurons were most numerous in the lumbar spinal cord, with moderate numbers in the caudal cervical cord, few in the rostral cervical cord, and almost none in the thoracic cord. All people with AMGHM interneurons had occasional AMGHM staining in α-motoneurons as well. In one man AMGHM staining was present in addition in dorsomedial nucleus and sensory neurons. In conclusion, heavy metals are present in many spinal interneurons, and in a few α-motoneurons, in a large proportion of older people. Damage to inhibitory interneurons from toxic metals in later life could result in excitotoxic injury to motoneurons and may underlie motoneuron injury or loss in conditions such as ALS/MND, multiple sclerosis, sarcopenia and calf fasciculations.

  12. Disease Mechanisms and Therapeutic Approaches in Spinal Muscular Atrophy

    Science.gov (United States)

    Tisdale, Sarah

    2015-01-01

    Motor neuron diseases are neurological disorders characterized primarily by the degeneration of spinal motor neurons, skeletal muscle atrophy, and debilitating and often fatal motor dysfunction. Spinal muscular atrophy (SMA) is an autosomal-recessive motor neuron disease of high incidence and severity and the most common genetic cause of infant mortality. SMA is caused by homozygous mutations in the survival motor neuron 1 (SMN1) gene and retention of at least one copy of the hypomorphic gene paralog SMN2. Early studies established a loss-of-function disease mechanism involving ubiquitous SMN deficiency and suggested SMN upregulation as a possible therapeutic approach. In recent years, greater knowledge of the central role of SMN in RNA processing combined with deep characterization of animal models of SMA has significantly advanced our understanding of the cellular and molecular basis of the disease. SMA is emerging as an RNA disease not limited to motor neurons, but one that involves dysfunction of motor circuits that comprise multiple neuronal subpopulations and possibly other cell types. Advances in SMA research have also led to the development of several potential therapeutics shown to be effective in animal models of SMA that are now in clinical trials. These agents offer unprecedented promise for the treatment of this still incurable neurodegenerative disease. PMID:26063904

  13. Modeling motor neuron disease : the matter of time

    NARCIS (Netherlands)

    Arbab, Mandana; Baars, Susanne; Geijsen, Niels

    2014-01-01

    Stem cell technologies have created new opportunities to generate unlimited numbers of human neurons in the lab and study neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Although some disease hallmarks have been reported in patient-derived

  14. Nuclear magnetic imaging for MTRA. Spinal canal and spinal cord

    International Nuclear Information System (INIS)

    Fritzsch, Dominik; Hoffmann, Karl-Titus

    2011-01-01

    The booklet covers the following topics: (1) Clinical indications for NMR imaging of spinal cord and spinal canal; (2) Methodic requirements: magnets and coils, image processing, contrast media: (3) Examination technology: examination conditions, sequences, examination protocols; (4) Disease pattern and indications: diseases of the myelin, the spinal nerves and the spinal canal (infections, tumors, injuries, ischemia and bleedings, malformations); diseases of the spinal cord and the intervertebral disks (degenerative changes, infections, injuries, tumors, malformations).

  15. PKMζ is essential for spinal plasticity underlying the maintenance of persistent pain

    Directory of Open Access Journals (Sweden)

    Laferrière Andre

    2011-12-01

    Full Text Available Abstract Background Chronic pain occurs when normally protective acute pain becomes pathologically persistent. We examined here whether an isoform of protein kinase C (PKC, PKMζ, that underlies long-term memory storage in various brain regions, also sustains nociceptive plasticity in spinal cord dorsal horn (SCDH mediating persistent pain. Results Cutaneous injury or spinal stimulation produced persistent increases of PKMζ, but not other atypical PKCs in SCDH. Inhibiting spinal PKMζ, but not full-length PKCs, reversed plasticity-dependent persistent painful responses to hind paw formalin and secondary mechanical hypersensitivity and SCDH neuron sensitization after hind paw capsaicin, without affecting peripheral sensitization-dependent primary heat hypersensitivity after hind paw capsaicin. Inhibiting spinal PKMζ, but not full-length PKCs, also reversed mechanical hypersensitivity in the rat hind paw induced by spinal stimulation with intrathecal dihydroxyphenylglycine. Spinal PKMζ inhibition also alleviated allodynia 3 weeks after ischemic injury in rats with chronic post-ischemia pain (CPIP, at a point when allodynia depends on spinal changes. In contrast, spinal PKMζ inhibition did not affect allodynia in rats with chronic contriction injury (CCI of the sciatic nerve, or CPIP rats early after ischemic injury, when allodynia depends on ongoing peripheral inputs. Conclusions These results suggest spinal PKMζ is essential for the maintenance of persistent pain by sustaining spinal nociceptive plasticity.

  16. Progranulin is expressed within motor neurons and promotes neuronal cell survival

    Directory of Open Access Journals (Sweden)

    Kay Denis G

    2009-10-01

    Full Text Available Abstract Background Progranulin is a secreted high molecular weight growth factor bearing seven and one half copies of the cysteine-rich granulin-epithelin motif. While inappropriate over-expression of the progranulin gene has been associated with many cancers, haploinsufficiency leads to atrophy of the frontotemporal lobes and development of a form of dementia (frontotemporal lobar degeneration with ubiquitin positive inclusions, FTLD-U associated with the formation of ubiquitinated inclusions. Recent reports indicate that progranulin has neurotrophic effects, which, if confirmed would make progranulin the only neuroprotective growth factor that has been associated genetically with a neurological disease in humans. Preliminary studies indicated high progranulin gene expression in spinal cord motor neurons. However, it is uncertain what the role of Progranulin is in normal or diseased motor neuron function. We have investigated progranulin gene expression and subcellular localization in cultured mouse embryonic motor neurons and examined the effect of progranulin over-expression and knockdown in the NSC-34 immortalized motor neuron cell line upon proliferation and survival. Results In situ hybridisation and immunohistochemical techniques revealed that the progranulin gene is highly expressed by motor neurons within the mouse spinal cord and in primary cultures of dissociated mouse embryonic spinal cord-dorsal root ganglia. Confocal microscopy coupled to immunocytochemistry together with the use of a progranulin-green fluorescent protein fusion construct revealed progranulin to be located within compartments of the secretory pathway including the Golgi apparatus. Stable transfection of the human progranulin gene into the NSC-34 motor neuron cell line stimulates the appearance of dendritic structures and provides sufficient trophic stimulus to survive serum deprivation for long periods (up to two months. This is mediated at least in part through

  17. Decerebrate mouse model for studies of the spinal cord circuits

    DEFF Research Database (Denmark)

    Meehan, Claire Francesca; Mayr, Kyle A; Manuel, Marin

    2017-01-01

    The adult decerebrate mouse model (a mouse with the cerebrum removed) enables the study of sensory-motor integration and motor output from the spinal cord for several hours without compromising these functions with anesthesia. For example, the decerebrate mouse is ideal for examining locomotor...... behavior using intracellular recording approaches, which would not be possible using current anesthetized preparations. This protocol describes the steps required to achieve a low-blood-loss decerebration in the mouse and approaches for recording signals from spinal cord neurons with a focus on motoneurons...

  18. The Neuroprotective Effect of Kefir on Spinal Cord Ischemia/Reperfusion Injury in Rats.

    Science.gov (United States)

    Guven, Mustafa; Akman, Tarik; Yener, Ali Umit; Sehitoglu, Muserref Hilal; Yuksel, Yasemin; Cosar, Murat

    2015-05-01

    The main causes of spinal cord ischemia are a variety of vascular pathologies causing acute arterial occlusions. We investigated neuroprotective effects of kefir on spinal cord ischemia injury in rats. Rats were divided into three groups : 1) sham operated control rats; 2) spinal cord ischemia group fed on a standard diet without kefir pretreatment; and 3) spinal cord ischemia group fed on a standard diet plus kefir. Spinal cord ischemia was performed by the infrarenal aorta cross-clamping model. The spinal cord was removed after the procedure. The biochemical and histopathological changes were observed within the samples. Functional assessment was performed for neurological deficit scores. The kefir group was compared with the ischemia group, a significant decrease in malondialdehyde levels was observed (pkefir group were significantly higher than ischemia group (pkefir group is compared with ischemia group, there was a significant decrease in numbers of dead and degenerated neurons (pkefir group compared with ischemia group (pkefir group were significantly higher than ischemia group at 24 h (pkefir pretreatment in spinal cord ischemia/reperfusion reduced oxidative stress and neuronal degeneration as a neuroprotective agent. Ultrastructural studies are required in order for kefir to be developed as a promising therapeutic agent to be utilized for human spinal cord ischemia in the future.

  19. Molecular mechanisms underlying monosynaptic sensory-motor circuit development in the spinal cord.

    Science.gov (United States)

    Imai, Fumiyasu; Yoshida, Yutaka

    2018-04-01

    Motor behaviors are precisely controlled by the integration of sensory and motor systems in the central nervous system (CNS). Proprioceptive sensory neurons, key components of the sensory system, are located in the dorsal root ganglia and project axons both centrally to the spinal cord and peripherally to muscles and tendons, communicating peripheral information about the body to the CNS. Changes in muscle length detected by muscle spindles, and tension variations in tendons conveyed by Golgi tendon organs, are communicated to the CNS through group Ia /II, and Ib proprioceptive sensory afferents, respectively. Group Ib proprioceptive sensory neurons connect with motor neurons indirectly through spinal interneurons, whereas group Ia/II axons form both direct (monosynaptic) and indirect connections with motor neurons. Although monosynaptic sensory-motor circuits between spindle proprioceptive sensory neurons and motor neurons have been extensively studied since 1950s, the molecular mechanisms underlying their formation and upkeep have only recently begun to be understood. We will discuss our current understanding of the molecular foundation of monosynaptic circuit development and maintenance involving proprioceptive sensory neurons and motor neurons in the mammalian spinal cord. Developmental Dynamics 247:581-587, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Electrophysiological and Anatomical Correlates of Spinal Cord Optical Coherence Tomography.

    Science.gov (United States)

    Giardini, Mario E; Zippo, Antonio G; Valente, Maurizio; Krstajic, Nikola; Biella, Gabriele E M

    2016-01-01

    Despite the continuous improvement in medical imaging technology, visualizing the spinal cord poses severe problems due to structural or incidental causes, such as small access space and motion artifacts. In addition, positional guidance on the spinal cord is not commonly available during surgery, with the exception of neuronavigation techniques based on static pre-surgical data and of radiation-based methods, such as fluoroscopy. A fast, bedside, intraoperative real-time imaging, particularly necessary during the positioning of endoscopic probes or tools, is an unsolved issue. The objective of our work, performed on experimental rats, is to demonstrate potential intraoperative spinal cord imaging and probe guidance by optical coherence tomography (OCT). Concurrently, we aimed to demonstrate that the electromagnetic OCT irradiation exerted no particular effect at the neuronal and synaptic levels. OCT is a user-friendly, low-cost and endoscopy-compatible photonics-based imaging technique. In particular, by using a Fourier-domain OCT imager, operating at 850 nm wavelength and scanning transversally with respect to the spinal cord, we have been able to: 1) accurately image tissue structures in an animal model (muscle, spine bone, cerebro-spinal fluid, dura mater and spinal cord), and 2) identify the position of a recording microelectrode approaching and inserting into the cord tissue 3) check that the infrared radiation has no actual effect on the electrophysiological activity of spinal neurons. The technique, potentially extendable to full three-dimensional image reconstruction, shows prospective further application not only in endoscopic intraoperative analyses and for probe insertion guidance, but also in emergency and adverse situations (e.g. after trauma) for damage recognition, diagnosis and fast image-guided intervention.

  1. Pramipexole Responsive Neck Numbness: The Therapeutic Role of Dopamine Agonists in the Spinal Cord Indicating to a Common Spinal Pathophysiology with Restless Leg Syndrome (RLS)?

    Science.gov (United States)

    Yulug, Burak; Hanoglu, Lütfü

    2016-01-01

    There is still speculative data regarding the role of spinal dopaminergic neurotransmission in restless leg syndrome (RLS). We evaluated the therapeutic role of pramipexole in a patient with cervical disc prolapsus who exceptionally presented with neck restlessness. We have found that pramipexole leads to a significant improvement in restlessness symptoms in the neck region. The therapeutic role of pramipexole may not only suggest secondary deficits due to spinal pathologies but also indicate that specialized spinal dopaminergic neurons may play an important role in the pathogenesis of region specific restlessness symptomatology.

  2. Regional differentiation of retinoic acid-induced human pluripotent embryonic carcinoma stem cell neurons.

    Directory of Open Access Journals (Sweden)

    Dennis E Coyle

    Full Text Available The NTERA2 cl D1 (NT2 cell line, derived from human teratocarcinoma, exhibits similar properties as embryonic stem (ES cells or very early neuroepithelial progenitors. NT2 cells can be induced to become postmitotic central nervous system neurons (NT2N with retinoic acid. Although neurons derived from pluripotent cells, such as NT2N, have been characterized for their neurotransmitter phenotypes, their potential suitability as a donor source for neural transplantation also depends on their ability to respond to localized environmental cues from a specific region of the CNS. Therefore, our study aimed to characterize the regional transcription factors that define the rostocaudal and dorsoventral identity of NT2N derived from a monolayer differentiation paradigm using quantitative PCR (qPCR. Purified NT2N mainly expressed both GABAergic and glutamatergic phenotypes and were electrically active but did not form functional synapses. The presence of immature astrocytes and possible radial glial cells was noted. The NT2N expressed a regional transcription factor code consistent with forebrain, hindbrain and spinal cord neural progenitors but showed minimal expression of midbrain phenotypes. In the dorsoventral plane NT2N expressed both dorsal and ventral neural progenitors. Of major interest was that even under the influence of retinoic acid, a known caudalization factor, the NT2N population maintained a rostral phenotype subpopulation which expressed cortical regional transcription factors. It is proposed that understanding the regional differentiation bias of neurons derived from pluripotent stem cells will facilitate their successful integration into existing neuronal networks within the CNS.

  3. Glutamate mediated astrocytic filtering of neuronal activity.

    Directory of Open Access Journals (Sweden)

    Gilad Wallach

    2014-12-01

    Full Text Available Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocytes specifically respond to the frequency of neuronal stimulation by intracellular Ca2+ transients, with a clear onset of astrocytic activation at neuron firing rates around 3-5 Hz. The cell-to-cell heterogeneity of the astrocyte Ca2+ response was however large and increasing with stimulation frequency. Astrocytic activation by neurons was abolished with antagonists of type I metabotropic glutamate receptor, validating the glutamate-dependence of this neuron-to-astrocyte pathway. Using a realistic biophysical model of glutamate-based intracellular calcium signaling in astrocytes, we suggest that the stepwise response is due to the supralinear dynamics of intracellular IP3 and that the heterogeneity of the responses may be due to the heterogeneity of the astrocyte-to-astrocyte couplings via gap junction channels. Therefore our results present astrocyte intracellular Ca2+ activity as a nonlinear integrator of glutamate-dependent neuronal activity.

  4. Glutamate Mediated Astrocytic Filtering of Neuronal Activity

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    Herzog, Nitzan; De Pittà, Maurizio; Jacob, Eshel Ben; Berry, Hugues; Hanein, Yael

    2014-01-01

    Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocytes specifically respond to the frequency of neuronal stimulation by intracellular Ca2+ transients, with a clear onset of astrocytic activation at neuron firing rates around 3-5 Hz. The cell-to-cell heterogeneity of the astrocyte Ca2+ response was however large and increasing with stimulation frequency. Astrocytic activation by neurons was abolished with antagonists of type I metabotropic glutamate receptor, validating the glutamate-dependence of this neuron-to-astrocyte pathway. Using a realistic biophysical model of glutamate-based intracellular calcium signaling in astrocytes, we suggest that the stepwise response is due to the supralinear dynamics of intracellular IP3 and that the heterogeneity of the responses may be due to the heterogeneity of the astrocyte-to-astrocyte couplings via gap junction channels. Therefore our results present astrocyte intracellular Ca2+ activity as a nonlinear integrator of glutamate-dependent neuronal activity. PMID:25521344

  5. Mechanical Dissociation of Retinal Neurons with Vibration

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    Motomura, Tamami; Hayashida, Yuki; Murayama, Nobuki

    The neuromorphic device, which implements the functions of biological neural circuits by means of VLSI technology, has been collecting much attention in the engineering fields in the last decade. Concurrently, progress in neuroscience research has revealed the nonlinear computation in single neuron levels, suggesting that individual neurons are not merely the circuit elements but computational units. Thus, elucidating the properties of neuronal signal processing is thought to be an essential step for developing the next generation of neuromorphic devices. In the present study, we developed a method for dissociating single neurons from specific sublayers of mammalian retinas with using no proteolytic enzymes but rather combining tissue incubation in a low-Ca2+ medium and the vibro-dissociation technique developed for the slices of brains and spinal cords previously. Our method took shorter time of the procedure, and required less elaborated skill, than the conventional enzymatic method did; nevertheless it yielded enough number of the cells available for acute electrophysiological experiments. The isolated retinal neurons were useful for measuring the nonlinear membrane conductances as well as the spike firing properties under the perforated-patch whole-cell configuration. These neurons also enabled us to examine the effects of proteolytic enzymes on the membrane excitability in those cells.

  6. New products tissue-engineering in the treatment of spinal cord injury

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    Bolshakov, I. N.; Sergienko, V. I.; Kiselev, S. L.; Lagarkova, M. A.; Remigaylo, A. A.; Mihaylov, A. A.; Prokopenko, S. V.

    2015-11-01

    In the treatment of patients with complicated spinal cord injury the Russian Health spends about one million rubles for each patient in the acute and the interim period after the injury. The number of complicated spinal cord injury is different in geographical areas Russian Federation from 30 to 50 people per 1 million that is affected by the year 5600. Applied to the present surgical and pharmacological techniques provide unsatisfactory results or minimally effective treatment. Transplantation of 100 thousand neuronal mouse predecessors (24 rats) or human neuronal predecessors (18 rats) in the anatomical gap rat spinal cord, followed by analysis of neurological deficit. The neuro-matrix implantation in the rat spinal cord containing 100 thousand neuronal precursors hESC, repeatable control neuro-matrix transplantation, non-cell mass, eliminating neurological deficit for 14 weeks after transplantation about 5-9 points on the scale of the BBB. The cultivation under conditions in vitro human induced pluripotent stem cells on collagen-chitosan matrix (hIPSC) showed that neurons differentiated from induced pluripotent stem cells grown on scaffolds as compact groups and has no neurites. Cells do not penetrate into the matrix during long-term cultivation and formed near the surface of the spherical structures resembling neurospheres. At least 90% of the cells were positive for the neuronal marker tubulin b3. Further studies should be performed to examine the compatibility of neuronal cultures and matrices.

  7. Neuronal Glud1 (glutamate dehydrogenase 1) over-expressing mice: increased glutamate formation and synaptic release, loss of synaptic activity, and adaptive changes in genomic expression.

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    Michaelis, E K; Wang, X; Pal, R; Bao, X; Hascup, K N; Wang, Y; Wang, W-T; Hui, D; Agbas, A; Choi, I-Y; Belousov, A; Gerhardt, G A

    2011-09-01

    Glutamate dehydrogenase 1 (GLUD1) is a mitochondrial enzyme expressed in all tissues, including brain. Although this enzyme is expressed in glutamatergic pathways, its function as a regulator of glutamate neurotransmitter levels is still not well defined. In order to gain an understanding of the role of GLUD1 in the control of glutamate levels and synaptic release in mammalian brain, we generated transgenic (Tg) mice that over-express this enzyme in neurons of the central nervous system. The Tg mice have increased activity of GLUD, as well as elevated levels and increased synaptic and depolarization-induced release of glutamate. These mice suffer age-associated losses of dendritic spines, nerve terminals, and neurons. The neuronal losses and dendrite structural changes occur in select regions of the brain. At the transcriptional level in the hippocampus, cells respond by increasing the expression of genes related to neurite growth and synapse formation, indications of adaptive or compensatory responses to the effects of increases in the release and action of glutamate at synapses. Because these Tg mice live to a relatively old age they are a good model of the effects of a "hyperglutamatergic" state on the aging process in the nervous system. The mice are also useful in defining the molecular pathways affected by the over-activation of GLUD in glutamatergic neurons of the brain and spinal cord. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Neuronal responses to tactile stimuli and tactile sensations evoked by microstimulation in the human thalamic principal somatic sensory nucleus (ventral caudal).

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    Schmid, Anne-Christine; Chien, Jui-Hong; Greenspan, Joel D; Garonzik, Ira; Weiss, Nirit; Ohara, Shinji; Lenz, Frederick Arthur

    2016-06-01

    The normal organization and plasticity of the cutaneous core of the thalamic principal somatosensory nucleus (ventral caudal, Vc) have been studied by single-neuron recordings and microstimulation in patients undergoing awake stereotactic operations for essential tremor (ET) without apparent somatic sensory abnormality and in patients with dystonia or chronic pain secondary to major nervous system injury. In patients with ET, most Vc neurons responded to one of the four stimuli, each of which optimally activates one mechanoreceptor type. Sensations evoked by microstimulation were similar to those evoked by the optimal stimulus only among rapidly adapting neurons. In patients with ET, Vc was highly segmented somatotopically, and vibration, movement, pressure, and sharp sensations were usually evoked by microstimulation at separate sites in Vc. In patients with conditions including spinal cord transection, amputation, or dystonia, RFs were mismatched with projected fields more commonly than in patients with ET. The representation of the border of the anesthetic area (e.g., stump) or of the dystonic limb was much larger than that of the same part of the body in patients with ET. This review describes the organization and reorganization of human Vc neuronal activity in nervous system injury and dystonia and then proposes basic mechanisms. Copyright © 2016 the American Physiological Society.

  9. Modeling trans-spinal direct current stimulation for the modulation of the lumbar spinal motor pathways

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    Kuck, A.; Stegeman, D. F.; van Asseldonk, E. H. F.

    2017-10-01

    Objective. Trans-spinal direct current stimulation (tsDCS) is a potential new technique for the treatment of spinal cord injury (SCI). TsDCS aims to facilitate plastic changes in the neural pathways of the spinal cord with a positive effect on SCI recovery. To establish tsDCS as a possible treatment option for SCI, it is essential to gain a better understanding of its cause and effects. We seek to understand the acute effect of tsDCS, including the generated electric