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Sample records for dorsal horn neuronal

  1. 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

  2. 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...

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

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    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

  4. 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...

  5. 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...

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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...

  9. Supraspinal modulation of neuronal synchronization by nociceptive stimulation induces an enduring reorganization of dorsal horn neuronal connectivity.

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    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

  10. Superficial dorsal horn neurons with double spike activity in the rat.

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    Rojas-Piloni, Gerardo; Dickenson, Anthony H; Condés-Lara, Miguel

    2007-05-29

    Superficial dorsal horn neurons promote the transfer of nociceptive information from the periphery to supraspinal structures. The membrane and discharge properties of spinal cord neurons can alter the reliability of peripheral signals. In this paper, we analyze the location and response properties of a particular class of dorsal horn neurons that exhibits double spike discharge with a very short interspike interval (2.01+/-0.11 ms). These neurons receive nociceptive C-fiber input and are located in laminae I-II. Double spikes are generated spontaneously or by depolarizing current injection (interval of 2.37+/-0.22). Cells presenting double spike (interval 2.28+/-0.11) increased the firing rate by electrical noxious stimulation, as well as, in the first minutes after carrageenan injection into their receptive field. Carrageenan is a polysaccharide soluble in water and it is used for producing an experimental model of semi-chronic pain. In the present study carrageenan also produces an increase in the interval between double spikes and then, reduced their occurrence after 5-10 min. The results suggest that double spikes are due to intrinsic membrane properties and that their frequency is related to C-fiber nociceptive activity. The present work shows evidence that double spikes in superficial spinal cord neurones are related to the nociceptive stimulation, and they are possibly part of an acute pain-control mechanism.

  11. 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...

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

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    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.

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

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    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.

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

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    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

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

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    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

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

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    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.

  17. Reactive Oxygen Species Donors Increase the Responsiveness of Dorsal Horn Neurons and Induce Mechanical Hyperalgesia in Rats

    Directory of Open Access Journals (Sweden)

    Hee Young Kim

    2015-01-01

    Full Text Available Our previous studies suggest that reactive oxygen species (ROS scavengers have analgesic effect on neuropathic pain through spinal mechanisms in the rat. The studies suggest that superoxide in spinal cord is one of important mediators of persistent pain. To test the hypothesis that increase of superoxide-derived intermediates leads to central sensitization and pain, the effects of an intrathecal injection of chemical ROS donors releasing either OH∙, OCl-, or H2O2 were examined on pain behaviors. Following treatment with t-BOOH (OH∙ donor, dorsal horn neuron responses to mechanical stimuli in normal rats and the changes of neuronal excitability were explored on substantia gelatinosa (SG neurons using whole-cell patch clamping recordings. Intrathecal administration of t-BOOH or NaOCl (OCl- donor, but not H2O2, significantly decreased mechanical thresholds of hind paws. The responses of wide dynamic range neurons to mechanical stimuli increased after a local application of t-BOOH. The t-BOOH increased the frequency and the amplitude of excitatory postsynaptic potentials, depolarized membrane potential in SG neurons, and increased the frequency of action potentials evoked by depolarizing current pulses. These results suggest that elevated ROS, especially OH∙, in the spinal cord sensitized dorsal horn neurons and produced hyperalgesia in normal rats.

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

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    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

  19. Connectivity of Pacemaker Neurons in the Neonatal Rat Superficial Dorsal Horn

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    Ford, Neil C.; Arbabi, Shahriar; Baccei, Mark L.

    2014-01-01

    Pacemaker neurons with an intrinsic ability to generate rhythmic burst-firing have been characterized in lamina I of the neonatal spinal cord, where they are innervated by high-threshold sensory afferents. However, little is known about the output of these pacemakers, as the neuronal populations which are targeted by pacemaker axons have yet to be identified. The present study combines patch clamp recordings in the intact neonatal rat spinal cord with tract-tracing to demonstrate that lamina I pacemaker neurons contact multiple spinal motor pathways during early life. Retrograde labeling of premotor interneurons with the trans-synaptic virus PRV-152 revealed the presence of burst-firing in PRV-infected lamina I neurons, thereby confirming that pacemakers are synaptically coupled to motor networks in the spinal ventral horn. Notably, two classes of pacemakers could be distinguished in lamina I based on cell size and the pattern of their axonal projections. While small pacemaker neurons possessed ramified axons which contacted ipsilateral motor circuits, large pacemaker neurons had unbranched axons which crossed the midline and ascended rostrally in the contralateral white matter. Recordings from identified spino-parabrachial and spino-PAG neurons indicated the presence of pacemaker activity within neonatal lamina I projection neurons. Overall, these results show that lamina I pacemakers are positioned to regulate both the level of activity in developing motor circuits as well as the ascending flow of nociceptive information to the brain, thus highlighting a potential role for pacemaker activity in the maturation of pain and sensorimotor networks in the CNS. PMID:25380417

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

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    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

  1. Central sensitization of nociceptive neurons in rat medullary dorsal horn involves purinergic P2X7 receptors.

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    Itoh, K; Chiang, C-Y; Li, Z; Lee, J-C; Dostrovsky, J O; Sessle, B J

    2011-09-29

    Central sensitization is a crucial process underlying the increased neuronal excitability of nociceptive pathways following peripheral tissue injury and inflammation. Our previous findings have suggested that extracellular adenosine 5'-triphosphate (ATP) molecules acting at purinergic receptors located on presynaptic terminals (e.g., P2X2/3, P2X3 subunits) and glial cells are involved in the glutamatergic-dependent central sensitization induced in medullary dorsal horn (MDH) nociceptive neurons by application to the tooth pulp of the inflammatory irritant mustard oil (MO). Since growing evidence indicates that activation of P2X7 receptors located on glia is involved in chronic inflammatory and neuropathic pain, the aim of the present study was to test in vivo for P2X7 receptor involvement in this acute inflammatory pain model. Experiments were carried out in anesthetized Sprague-Dawley male rats. Single unit recordings were made in MDH functionally identified nociceptive neurons for which mechanoreceptive field, mechanical activation threshold and responses to noxious stimuli were tested. We found that continuous intrathecal (i.t.) superfusion over MDH of the potent P2X7 receptor antagonists brilliant blue G and periodated oxidized ATP could each significantly attenuate the MO-induced MDH central sensitization. MDH central sensitization could also be produced by i.t. superfusion of ATP and even more effectively by the P2X7 receptor agonist benzoylbenzoyl ATP. Superfusion of the microglial blocker minocycline abolished the MO-induced MDH central sensitization, consistent with reports that dorsal horn P2X7 receptors are mostly expressed on microglia. In control experiments, superfusion over MDH of vehicle did not produce any significant changes. These novel findings suggest that activation of P2X7 receptors in vivo may be involved in the development of central sensitization in an acute inflammatory pain model. Copyright © 2011 IBRO. All rights reserved.

  2. 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

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    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

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

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    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.

  4. 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.

  5. 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.

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    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

  6. 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.

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    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

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

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    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.

  8. Nerve injury-induced calcium channel alpha-2-delta-1 protein dysregulation leads to increased pre-synaptic excitatory input into deep dorsal horn neurons and neuropathic allodynia

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    Zhou, Chunyi; Luo, Z. David

    2015-01-01

    Background Upregulation of voltage-gated-calcium-channel α2δ1 subunit post spinal nerve ligation injury (SNL) or in α2δ1-overexpressing transgenic (Tg) mice correlates with tactile allodynia, a pain state mediated mainly by Aβ sensory fibers forming synaptic connections with deep dorsal horn neurons. It is not clear however whether dysregulated α2δ1 alters deep dorsal horn synaptic neurotransmission that underlies tactile allodynia development post nerve injury. Methods Tactile allodynia was tested in the SNL and α2δ1 Tg models. Miniature excitatory/inhibitory postsynaptic currents were recorded in deep dorsal horn (DDH) neurons from these animal models using whole cell patch clamp slice recording techniques.. Results There was a significant increase in the frequency, but not amplitude, of miniature excitatory postsynaptic currents (mEPSC) in DDH neurons that correlated with tactile allodynia in SNL and α2δ1 Tg mice. Gabapentin, an α2δ1 ligand that is known to block tactile allodynia in these models, also normalized mEPSC frequency dose-dependently in DDH neurons from SNL and α2δ1 Tg mice. In contrast, neither frequency nor amplitude of miniature inhibitory postsynaptic currents (mIPSC) was altered in DDH neurons from SNL and α2δ1 Tg mice. Conclusion Our data suggest that α2δ1 dysregulation is highly likely contributing to tactile allodynia through a pre-synaptic mechanism involving facilitation of excitatory synaptic neurotransmission in deep dorsal horn of spinal cord. PMID:25691360

  9. PKCα is required for inflammation-induced trafficking of extrasynaptic AMPA receptors in tonically firing lamina II dorsal horn neurons during the maintenance of persistent inflammatory pain.

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    Kopach, Olga; Viatchenko-Karpinski, Viacheslav; Atianjoh, Fidelis E; Belan, Pavel; Tao, Yuan-Xiang; Voitenko, Nana

    2013-02-01

    Persistent inflammation promotes internalization of synaptic GluR2-containing, Ca(2+)-impermeable AMPA receptors (AMPARs) and insertion of GluR1-containing, Ca(2+)-permeable AMPARs at extrasynaptic sites in dorsal horn neurons. Previously we have shown that internalization of synaptic GluR2-containing AMPARs requires activation of spinal cord protein kinase C alpha (PKCα), but molecular mechanisms that underlie altered trafficking of extrasynaptic AMPARs are unclear. Here, using antisense (AS) oligodeoxynucleotides (ODN) that specifically knock down PKCα, we found that a decrease in dorsal horn PKCα expression prevents complete Freund's adjuvant (CFA)-induced increase in functional expression of extrasynaptic Ca(2+)-permeable AMPARs in substantia gelatinosa (SG) neurons of the rat spinal cord. Augmented AMPA-induced currents and associated [Ca(2+)](i) transients were abolished, and the current rectification 1 day post-CFA was reversed. These changes were observed specifically in SG neurons characterized by intrinsic tonic firing properties, but not in those that exhibited strong adaptation. Finally, dorsal horn PKCα knockdown produced an antinociceptive effect on CFA-induced thermal and mechanical hypersensitivity during the maintenance period of inflammatory pain, indicating a role for PKCα in persistent inflammatory pain maintenance. Our results indicate that inflammation-induced trafficking of extrasynaptic Ca(2+)-permeable AMPARs in tonically firing SG neurons depends on PKCα, and that this PKCα-dependent trafficking may contribute to persistent inflammatory pain maintenance. This study shows that PKCα knockdown blocks inflammation-induced upregulation of extrasynaptic Ca(2+)-permeable AMPARs in dorsal horn neurons and produces an antinociceptive effect during the maintenance period of inflammatory pain. These findings have potential implications for use of PKCα gene-silencing therapy to prevent and/or treat persistent inflammatory pain. Copyright

  10. Expression of Nav1.7 in DRG neurons extends from peripheral terminals in the skin to central preterminal branches and terminals in the dorsal horn

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    Black Joel A

    2012-11-01

    Full Text Available Abstract Background Sodium channel Nav1.7 has emerged as a target of considerable interest in pain research, since loss-of-function mutations in SCN9A, the gene that encodes Nav1.7, are associated with a syndrome of congenital insensitivity to pain, gain-of-function mutations are linked to the debiliting chronic pain conditions erythromelalgia and paroxysmal extreme pain disorder, and upregulated expression of Nav1.7 accompanies pain in diabetes and inflammation. Since Nav1.7 has been implicated as playing a critical role in pain pathways, we examined by immunocytochemical methods the expression and distribution of Nav1.7 in rat dorsal root ganglia neurons, from peripheral terminals in the skin to central terminals in the spinal cord dorsal horn. Results Nav1.7 is robustly expressed within the somata of peptidergic and non-peptidergic DRG neurons, and along the peripherally- and centrally-directed C-fibers of these cells. Nav1.7 is also expressed at nodes of Ranvier in a subpopulation of Aδ-fibers within sciatic nerve and dorsal root. The peripheral terminals of DRG neurons within skin, intraepidermal nerve fibers (IENF, exhibit robust Nav1.7 immunolabeling. The central projections of DRG neurons in the superficial lamina of spinal cord dorsal horn also display Nav1.7 immunoreactivity which extends to presynaptic terminals. Conclusions The expression of Nav1.7 in DRG neurons extends from peripheral terminals in the skin to preterminal central branches and terminals in the dorsal horn. These data support a major contribution for Nav1.7 in pain pathways, including action potential electrogenesis, conduction along axonal trunks and depolarization/invasion of presynaptic axons. The findings presented here may be important for pharmaceutical development, where target engagement in the right compartment is essential.

  11. Long-term actions of interleukin-1beta on delay and tonic firing neurons in rat superficial dorsal horn and their relevance to central sensitization.

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    Gustafson-Vickers, Sabrina L; Lu, Van B; Lai, Aaron Y; Todd, Kathryn G; Ballanyi, Klaus; Smith, Peter A

    2008-12-17

    Cytokines such as interleukin 1beta (IL-1beta) have been implicated in the development of central sensitization that is characteristic of neuropathic pain. To examine its long-term effect on nociceptive processing, defined medium organotypic cultures of rat spinal cord were exposed to 100 pM IL-1beta for 6-8 d. Interleukin effects in the dorsal horn were examined by whole-cell patch-clamp recording and Ca(2+) imaging techniques. Examination of the cultures with confocal Fluo-4 AM imaging showed that IL-1beta increased the change in intracellular Ca(2+) produced by exposure to 35-50 mM K+. This is consistent with a modest increase in overall dorsal horn excitability. Despite this, IL-1beta did not have a direct effect on rheobase or resting membrane potential nor did it selectively destroy any specific neuronal population. All effects were instead confined to changes in synaptic transmission. A variety of pre- and postsynaptic actions of IL-1beta were seen in five different electrophysiologically-defined neuronal phenotypes. In putative excitatory 'delay' neurons, cytokine treatment increased the amplitude of spontaneous EPSC's (sEPSC) and decreased the frequency of spontaneous IPSC's (sIPSC). These effects would be expected to increase dorsal horn excitability and to facilitate the transfer of nociceptive information. However, other actions of IL-1beta included disinhibition of putative inhibitory 'tonic' neurons and an increase in the amplitude of sIPSC's in 'delay' neurons. Since spinal microglial activation peaks between 3 and 7 days after the initiation of chronic peripheral nerve injury and these cells release IL-1beta at this time, our findings define some of the neurophysiological mechanisms whereby nerve-injury induced release of IL-1beta may contribute to the central sensitization associated with chronic neuropathic pain.

  12. Long-term actions of interleukin-1β on delay and tonic firing neurons in rat superficial dorsal horn and their relevance to central sensitization

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    Ballanyi Klaus

    2008-12-01

    Full Text Available Abstract Background Cytokines such as interleukin 1β (IL-1β have been implicated in the development of central sensitization that is characteristic of neuropathic pain. To examine its long-term effect on nociceptive processing, defined medium organotypic cultures of rat spinal cord were exposed to 100 pM IL-1β for 6–8 d. Interleukin effects in the dorsal horn were examined by whole-cell patch-clamp recording and Ca2+ imaging techniques. Results Examination of the cultures with confocal Fluo-4 AM imaging showed that IL-1β increased the change in intracellular Ca2+ produced by exposure to 35–50 mM K+. This is consistent with a modest increase in overall dorsal horn excitability. Despite this, IL-1β did not have a direct effect on rheobase or resting membrane potential nor did it selectively destroy any specific neuronal population. All effects were instead confined to changes in synaptic transmission. A variety of pre- and postsynaptic actions of IL-1β were seen in five different electrophysiologically-defined neuronal phenotypes. In putative excitatory 'delay' neurons, cytokine treatment increased the amplitude of spontaneous EPSC's (sEPSC and decreased the frequency of spontaneous IPSC's (sIPSC. These effects would be expected to increase dorsal horn excitability and to facilitate the transfer of nociceptive information. However, other actions of IL-1β included disinhibition of putative inhibitory 'tonic' neurons and an increase in the amplitude of sIPSC's in 'delay' neurons. Conclusion Since spinal microglial activation peaks between 3 and 7 days after the initiation of chronic peripheral nerve injury and these cells release IL-1β at this time, our findings define some of the neurophysiological mechanisms whereby nerve-injury induced release of IL-1β may contribute to the central sensitization associated with chronic neuropathic pain.

  13. Different forms of glycine- and GABAA-receptor mediated inhibitory synaptic transmission in mouse superficial and deep dorsal horn neurons

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    Brichta Alan M

    2009-11-01

    Full Text Available Abstract Background Neurons in superficial (SDH and deep (DDH laminae of the spinal cord dorsal horn receive sensory information from skin, muscle, joints and viscera. In both regions, glycine- (GlyR and GABAA-receptors (GABAARs contribute to fast synaptic inhibition. For rat, several types of GABAAR coexist in the two regions and each receptor type provides different contributions to inhibitory tone. Recent work in mouse has discovered an additional type of GlyR, (containing alpha 3 subunits in the SDH. The contribution of differing forms of the GlyR to sensory processing in SDH and DDH is not understood. Methods and Results Here we compare fast inhibitory synaptic transmission in mouse (P17-37 SDH and DDH using patch-clamp electrophysiology in transverse spinal cord slices (L3-L5 segments, 23°C. GlyR-mediated mIPSCs were detected in 74% (25/34 and 94% (25/27 of SDH and DDH neurons, respectively. In contrast, GABAAR-mediated mIPSCs were detected in virtually all neurons in both regions (93%, 14/15 and 100%, 18/18. Several Gly- and GABAAR properties also differed in SDH vs. DDH. GlyR-mediated mIPSC amplitude was smaller (37.1 ± 3.9 vs. 64.7 ± 5.0 pA; n = 25 each, decay time was slower (8.5 ± 0.8 vs. 5.5 ± 0.3 ms, and frequency was lower (0.15 ± 0.03 vs. 0.72 ± 0.13 Hz in SDH vs. DDH neurons. In contrast, GABAAR-mediated mIPSCs had similar amplitudes (25.6 ± 2.4, n = 14 vs. 25. ± 2.0 pA, n = 18 and frequencies (0.21 ± 0.08 vs. 0.18 ± 0.04 Hz in both regions; however, decay times were slower (23.0 ± 3.2 vs. 18.9 ± 1.8 ms in SDH neurons. Mean single channel conductance underlying mIPSCs was identical for GlyRs (54.3 ± 1.6 pS, n = 11 vs. 55.7 ± 1.8, n = 8 and GABAARs (22.7 ± 1.7 pS, n = 10 vs. 22.4 ± 2.0 pS, n = 11 in both regions. We also tested whether the synthetic endocanabinoid, methandamide (methAEA, had direct effects on Gly- and GABAARs in each spinal cord region. MethAEA (5 μM reduced GlyR-mediated mIPSC frequency in SDH

  14. The effects of protein phosphatase inhibitors on the duration of central sensitization of rat dorsal horn neurons following injection of capsaicin

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    Fang Li

    2006-07-01

    Full Text Available Abstract Protein kinases and phosphatases catalyze opposing reactions of phosphorylation and dephosphorylation, which may modulate the function of crucial signaling proteins in central nervous system. This is an important mechanism in the regulation of intracellular signal transduction pathways in nociceptive neurons. To explore the role of protein phosphatase in central sensitization of spinal nociceptive neurons following peripheral noxious stimulation, using electrophysiological recording techniques, we investigated the role of two inhibitors of protein phosphatase type 2A (PP2A, fostriecin and okadaic acid (OA, on the responses of dorsal horn neurons to mechanical stimuli in anesthetized rats following intradermal injection of capsaicin. Central sensitization was initiated by injection of capsaicin into the plantar surface of the left paw. A microdialysis fiber was implanted in the spinal cord dorsal horn for perfusion of ACSF and inhibitors of PP2A, fostriecin and okadaic acid. We found that in ACSF pretreated animals, the responses to innocuous and noxious stimuli following capsaicin injection increased over a period of 15 min after injection and had mostly recovered by 60 min later. However, pre- or post-treatment with the phosphatase inhibitors, fostriecin or OA, significantly enhanced the effects of capsaicin injection by prolonging the responses to more than 3 hours. These results confirm that blockade of protein phosphatase activity may potentiate central sensitization of nociceptive transmission in the spinal cord following capsaicin injection and indicate that protein phosphatase type 2A may be involved in determining the duration of capsaicin-induced central sensitization.

  15. 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.

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

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    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.

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    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. Neuropeptide Y receptor-expressing dorsal horn neurons: role in nocifensive reflex and operant responses to aversive cold after CFA inflammation.

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    Lemons, L L; Wiley, R G

    2012-08-02

    The spinal Neuropeptide Y (NPY) system is a potential target for development of new pain therapeutics. NPY and two of its receptors (Y1 and Y2) are found in the superficial dorsal horn of the spinal cord, a key area of nociceptive gating and modulation. Lumbar intrathecal injection of (NPY) is antinociceptive, reducing hyper-reflexia to thermal and mechanical stimulation, particularly after nerve injury and inflammation. We have also shown that intrathecal injection of the targeted cytotoxin, Neuropeptide Y-sap (NPY-sap), is also antinociceptive, reducing nocifensive reflex responses to noxious heat and formalin. In the present study, we sought to determine the role of dorsal horn Y1R-expressing neurons in pain by destroying them with NPY-sap and testing the rats on three operant tasks. Lumbar intrathecal NPY-sap (1) reduced Complete Freund's Adjuvant (CFA)-induced hyper-reflexia on the 10°C cold plate, (2) reduced cold aversion on the thermal preference and escape tasks, (3) was analgesic to noxious heat on the escape task, (4) reduced the CFA-induced allodynia to cold temperatures experienced on the thermal preference, feeding interference, and escape tasks, and (5) did not inhibit or interfere with morphine analgesia. Published by Elsevier Ltd.

  19. Tumor necrosis factor α modulates sodium-activated potassium channel SLICK in rat dorsal horn neurons via p38 MAPK activation pathway

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    Wang K

    2017-05-01

    Full Text Available Kun Wang,1 Feng Wang,1 Jun-Ping Bao,2 Zhi-Yang Xie,1 Lu Chen,1 Bao-Yi Zhou,1 Xin-Hui Xie,2 Xiao-Tao Wu1,2 1Medical School of Southeast University, 2Department of Orthopaedics, Zhongda Hospital, Southeast University, Nanjing, People’s Republic of China Abstract: The dorsal horn (DH of the spinal cord is the integrative center that processes and transmits pain sensation. Abnormal changes in ion channel expression can enhance the excitability of pain-related DH neurons. Sodium-activated potassium (KNa channels are highly expressed particularly in the central nervous system; however, information about whether rat DH neurons express the SLICK channel protein is lacking, and the direct effects on SLICK in response to inflammation and the potential signaling pathway mediating such effects are yet to be elucidated. Here, using cultured DH neurons, we have shown that tumor necrosis factor-α inhibits the total outward potassium current IK and the KNa current predominantly as well as induces a progressive loss of firing accommodation. However, we found that this change in channel activity is offset by the p38 inhibitor SB202190, thereby suggesting the modulation of SLICK channel activity via the p38 MAPK pathway. Furthermore, we have demonstrated that the tumor necrosis factor-α modulation of KNa channels does not occur at the level of SLICK channel gating but arises from possible posttranslational modification. Keywords: p38 MAPK, SLICK channel, neuropathic pain, dorsal horn, TNF-α

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

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    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.

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

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    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.

  2. 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

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    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.

  3. 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.

  4. 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.

  5. 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

  6. Spinal dorsal horn astrocytes: New players in chronic itch

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    Makoto Tsuda

    2017-01-01

    Full Text Available Chronic itch is a debilitating symptom of inflammatory skin conditions, such as atopic dermatitis, and systemic diseases, for which existing treatment is largely ineffective. Recent studies have revealed the selective neuronal pathways that are involved in itch sensations; however, the mechanisms by which itch turns into a pathological chronic state are poorly understood. Recent advances in our understanding of the mechanisms producing chronic itch have been made by defining causal roles for astrocytes in the spinal dorsal horn in mouse models of chronic itch including atopic dermatitis. Understanding the key roles of astrocytes may provide us with exciting insights into the mechanisms for itch chronicity and lead to a previously unrecognized target for treating chronic itch.

  7. Glutamine uptake contributes to central sensitization in the medullary dorsal horn

    OpenAIRE

    Chiang, Chen Yu; Li, Zhaohui; Dostrovsky, Jonathan O.; Hu, James W.; Sessle, Barry J.

    2008-01-01

    Mustard oil application to tooth pulp produces central sensitization in rat medullary dorsal horn (MDH) nociceptive neurons, which has been implicated in persistent pain mechanisms. We found that superfusion onto MDH of methylaminoisobutyric acid, a competitive inhibitor of the neuronal system A transporter for presynaptic uptake of glutamine (a glutamate precursor released from astroglia), significantly depressed development of mustard oil-induced central sensitization in rat MDH nociceptive...

  8. Central sensitization in medullary dorsal horn involves gap junctions and hemichannels

    OpenAIRE

    Chiang, Chen Yu; Li, Zhaohui; Dostrovsky, Jonathan O.; Sessle, Barry J.

    2010-01-01

    Central sensitization is a fundamental mechanism contributing to acute and chronic pain conditions. Our previous studies have documented a glutamatergic-, purinergic- and glial-dependent central sensitization that can be induced in rat medullary dorsal horn (MDH) nociceptive neurons by mustard oil (MO) application to the tooth pulp. The present study demonstrated that carbenoxolone, a potent gap junction and hemichannel blocker, completely blocked all parameters of MO-induced central sensitiz...

  9. [Pathophysiology of neuropathic pain: molecular mechanisms underlying central sensitization in the dorsal horn in neuropathic pain].

    Science.gov (United States)

    Yamanaka, Hiroki; Noguchi, Koichi

    2012-11-01

    Neuropathic pain syndromes are clinically characterized by spontaneous pain and evoked pain (hyperalgesia and allodynia). The optimal treatment approach for neuropathic pain is still under development because of the complex pathological mechanisms underlying this type of pain. The spinal cord is an important gateway thorough which peripheral pain signals are transmitted to the brain, and sensitization of the spinal neurons is one of the important mechanisms underlying neuropathic pain. Central sensitization represents enhancement of the function of neuronal circuits in nociceptive pathways and is a manifestation of the remarkable plasticity of the somatosensory nervous system after nerve injury. This review highlights the pathological features of central sensitization, which develops because of (1) injury-induced abnormal inputs from primary afferents, (2) increase in the excitability of dorsal horn neurons, and (3) activated glial cell-derived signals.

  10. Synaptically evoked glutamate transporter currents in Spinal Dorsal Horn Astrocytes

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    Dougherty Patrick M

    2009-07-01

    Full Text Available Abstract Background Removing and sequestering synaptically released glutamate from the extracellular space is carried out by specific plasma membrane transporters that are primarily located in astrocytes. Glial glutamate transporter function can be monitored by recording the currents that are produced by co-transportation of Na+ ions with the uptake of glutamate. The goal of this study was to characterize glutamate transporter function in astrocytes of the spinal cord dorsal horn in real time by recording synaptically evoked glutamate transporter currents. Results Whole-cell patch clamp recordings were obtained from astrocytes in the spinal substantia gelatinosa (SG area in spinal slices of young adult rats. Glutamate transporter currents were evoked in these cells by electrical stimulation at the spinal dorsal root entry zone in the presence of bicuculline, strychnine, DNQX and D-AP5. Transporter currents were abolished when synaptic transmission was blocked by TTX or Cd2+. Pharmacological studies identified two subtypes of glutamate transporters in spinal astrocytes, GLAST and GLT-1. Glutamate transporter currents were graded with stimulus intensity, reaching peak responses at 4 to 5 times activation threshold, but were reduced following low-frequency (0.1 – 1 Hz repetitive stimulation. Conclusion These results suggest that glutamate transporters of spinal astrocytes could be activated by synaptic activation, and recording glutamate transporter currents may provide a means of examining the real time physiological responses of glial cells in spinal sensory processing, sensitization, hyperalgesia and chronic pain.

  11. Immunofluorescence characterization of spinal cord dorsal horn microglia and astrocytes in horses.

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    Meneses, Constanza Stefania; Müller, Heine Yacob; Herzberg, Daniel Eduardo; Uberti, Benjamín; Bustamante, Hedie Almagro; Werner, Marianne Patricia

    2017-01-01

    characterization of cell morphology and organizational aspects of horse spinal glia. Iba-1 and GFAP/Cx-43 can successfully immune-label microglia and astrocytes respectively in horse spinal cords, and thus reveal cell morphology and corresponding distribution within the dorsal horn laminae of healthy horses. The conventional hyper-ramified shape that is normally visible in resting microglial cells was not found in horses. Instead, horse microglial cells had an amoeboid spherical shape. Horse protoplasmic astroglia is significantly smaller and structurally less complex than human astrocytes, with fewer main GFAP processes. Instead, horse astrocytes tend to be similar to those found in rodent's model, with small somas and large cell processes. Microglia and astrocytes were found in the more superficial regions of the dorsal horn, similarly to that previously observed in humans and rodents. Further studies are needed to demonstrate the molecular mechanisms involved in the neuron-glia interaction in horses.

  12. Immunofluorescence characterization of spinal cord dorsal horn microglia and astrocytes in horses

    Directory of Open Access Journals (Sweden)

    Constanza Stefania Meneses

    2017-10-01

    characterization of cell morphology and organizational aspects of horse spinal glia. Iba-1 and GFAP/Cx-43 can successfully immune-label microglia and astrocytes respectively in horse spinal cords, and thus reveal cell morphology and corresponding distribution within the dorsal horn laminae of healthy horses. The conventional hyper-ramified shape that is normally visible in resting microglial cells was not found in horses. Instead, horse microglial cells had an amoeboid spherical shape. Horse protoplasmic astroglia is significantly smaller and structurally less complex than human astrocytes, with fewer main GFAP processes. Instead, horse astrocytes tend to be similar to those found in rodent’s model, with small somas and large cell processes. Microglia and astrocytes were found in the more superficial regions of the dorsal horn, similarly to that previously observed in humans and rodents. Further studies are needed to demonstrate the molecular mechanisms involved in the neuron-glia interaction in horses.

  13. Chronic morphine treatment enhances sciatic nerve stimulation-induced immediate early gene expression in the rat dorsal horn.

    Science.gov (United States)

    Bojovic, Ognjen; Bramham, Clive R; Tjølsen, Arne

    2015-01-01

    Synaptic plasticity is a property of neurons that can be induced by conditioning electrical stimulation (CS) of afferent fibers in the spinal cord. This is a widely studied property of spinal cord and hippocampal neurons. CS has been shown to trigger enhanced expression of immediate early gene proteins (IEGPs), with peak increases observed 2 hour post stimulation. Chronic morphine treatment has been shown to promoteinduce opioid-induced hyperalgesia, and also to increase CS-induced central sensitization in the dorsal horn. As IEGP expression may contribute to development of chronic pain states, we aimed to determine whether chronic morphine treatment affects the expression of IEGPs following sciatic nerve CS. Changes in expression of the IEGPs Arc, c-Fos or Zif268 were determined in cells of the lumbar dorsal horn of the spinal cord. Chronic Morphine pretreatment over 7 days led to a significant increase in the number of IEGP positive cells observed at both 2 h and 6 h after CS. The same pattern of immunoreactivity was obtained for all IEGPs, with peak increases occurring at 2 h post CS. In contrast, morphine treatment alone in sham operated animals had no effect on IEGP expression. We conclude that chronic morphine treatment enhances stimulus-induced expression of IEGPs in the lumbar dorsal horn. These data support the notion that morphine alters gene expression responses linked to nociceptive stimulation and plasticity.

  14. Early spread of hyperexcitability to caudal dorsal horn networks after a chemically-induced lesion of the rat spinal cord in vitro.

    Science.gov (United States)

    Deumens, R; Mazzone, G L; Taccola, G

    2013-01-15

    Hyperexcitability of dorsal horn neurons has been shown to play a key role in neuropathic pain following chronic experimental spinal cord injury. With a neonatal in vitro spinal cord injury model, we show that a chemically-induced lesion leads to rapid gain-of-function of sublesional dorsal horn networks biased to hyperexcitation. The expression of the GABA synthetic enzyme GAD65 was significantly reduced at the same level of the spinal cord, suggesting a compromised inhibitory system. We propose that our model could be useful to test early approaches to contrast spinal cord injury-induced central sensitization of dorsal horn circuits. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. MHC-I promotes apoptosis of GABAergic interneurons in the spinal dorsal horn and contributes to cancer induced bone pain.

    Science.gov (United States)

    Fu, Qiaochu; Shi, Dai; Zhou, Yaqun; Zheng, Hua; Xiang, Hongbing; Tian, Xuebi; Gao, Feng; Manyande, Anne; Cao, Fei; Tian, Yuke; Ye, Dawei

    2016-12-01

    Cancer induced bone pain (CIBP) remains one of the most intractable clinical problems due to poor understanding of its underlying mechanisms. Recent studies demonstrate the decline of inhibitory interneurons, especially GABAergic interneurons in the spinal cord, can evoke generation of chronic pain. It has also been reported that neuronal MHC-I expression renders neurons vulnerable to cytotoxic CD8 + T cells and finally lead to neurons apoptosis in a variety neurological disorders. However, whether MHC-I could induce the apoptosis of GABAergic interneurons in spinal cord and contribute to the development of CIBP remains unknown. In this study, we investigated roles of MHC-I and underlying mechanisms in CIBP on a rat model. Our results showed that increased MHC-I expression on GABAergic interneurons could deplete GABAergic interneurons by inducing their apoptosis in the spinal dorsal horn of tumor-bearing rats. Pretreatment of MHC-I RNAi-lentivirus could prevent the apoptosis of GABAergic interneurons and therefore alleviated mechanical allodynia induced by tumor cells intratibial injection. Additionally, we also found that CD8 + T cells were colocalized with MHC-I and GABAergic neurons and presented a significant and persistent increase in the spinal cord of tumor-bearing rats. Taken together, these findings indicated that MHC-I could evoke CIBP by promoting apoptosis of GABAergic interneurons in the dorsal horn, and this apoptosis was closely related to local CD8 + T cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Structural and molecular alterations of primary afferent fibres in the spinal dorsal horn in vincristine-induced neuropathy in rat.

    Science.gov (United States)

    Thibault, Karine; Rivals, Isabelle; M'Dahoma, Saïd; Dubacq, Sophie; Pezet, Sophie; Calvino, Bernard

    2013-11-01

    Vincristine is one of the most common anti-cancer drug therapies administered for the treatment of many types of cancer. Its dose-limiting side effect is the emergence of peripheral neuropathy, resulting in chronic neuropathic pain in many patients. This study sought to understand the mechanisms underlying the development of neuropathic pain by vincristine-induced neurotoxicity. We focused on signs of functional changes and revealed that deep layers of the spinal cord (III-IV) experience increased neuronal activity both in the absence of peripheral stimulation and, as a result of tactile mechanical stimulations. These laminae and superficial laminae I-II were also subject to structural changes as evidenced by an increase in immunoreactivity of Piccolo, a marker of active presynaptic elements. Further investigations performed, using DNA microarray technology, describe a large number of genes differentially expressed in dorsal root ganglions and in the spinal dorsal horn after vincristine treatment. Our study describes an important list of genes differentially regulated by vincristine treatment that will be useful for future studies and brings forward evidence for molecular and anatomical modifications of large diameter sensory neurons terminating in deep dorsal horn laminae, which could participate in the development of tactile allodynia.

  17. Depletion of vesicular zinc in dorsal horn of spinal cord causes increased neuropathic pain in mice

    DEFF Research Database (Denmark)

    Jo, Seung; Danscher, Gorm; Schrøder, Henrik

    2008-01-01

    pain. The animals were then sacrificed 5 days later. The ZnT3 immunoreactivity was found to have decreased significantly in dorsal horn of fourth, fifth, and sixth lumbar segments. In parallel with the depressed ZnT3 immunoreactivity the amount of vesicular zinc decreased perceptibly in superficial...

  18. NR2 subunits and NMDA receptors on lamina II inhibitory and excitatory interneurons of the mouse dorsal horn

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    MacDermott Amy B

    2010-05-01

    Full Text Available Abstract Background NMDA receptors expressed by spinal cord neurons in the superficial dorsal horn are involved in the development of chronic pain associated with inflammation and nerve injury. The superficial dorsal horn has a complex and still poorly understood circuitry that is mainly populated by inhibitory and excitatory interneurons. Little is known about how NMDA receptor subunit composition, and therefore pharmacology and voltage dependence, varies with neuronal cell type. NMDA receptors are typically composed of two NR1 subunits and two of four NR2 subunits, NR2A-2D. We took advantage of the differences in Mg2+ sensitivity of the NMDA receptor subtypes together with subtype preferring antagonists to identify the NR2 subunit composition of NMDA receptors expressed on lamina II inhibitory and excitatory interneurons. To distinguish between excitatory and inhibitory interneurons, we used transgenic mice expressing enhanced green fluorescent protein driven by the GAD67 promoter. Results Analysis of conductance ratio and selective antagonists showed that lamina II GABAergic interneurons express both the NR2A/B containing Mg2+ sensitive receptors and the NR2C/D containing NMDA receptors with less Mg2+ sensitivity. In contrast, excitatory lamina II interneurons express primarily NR2A/B containing receptors. Despite this clear difference in NMDA receptor subunit expression in the two neuronal populations, focally stimulated synaptic input is mediated exclusively by NR2A and 2B containing receptors in both neuronal populations. Conclusions Stronger expression of NMDA receptors with NR2C/D subunits by inhibitory interneurons compared to excitatory interneurons may provide a mechanism to selectively increase activity of inhibitory neurons during intense excitatory drive that can provide inhibitory feedback.

  19. Localization of cytochrome oxidase in the mammalian spinal cord and dorsal root ganglia, with quantitative analysis of ventral horn cells in monkeys.

    Science.gov (United States)

    Wong-Riley, M T; Kageyama, G H

    1986-03-01

    The spinal cord and dorsal root ganglia of mice, rats, cats, squirrel monkeys, and macaque monkeys were examined at both the light and electron microscopic levels for cytochrome oxidase activity. A similar histochemical pattern prevailed in all of the species examined. While the spinal gray exhibited a heterogeneous but consistent distribution of the enzyme, the white matter was only lightly stained. Highly reactive neurons were either singly scattered or aggregated into discrete clusters. The dorsal nucleus of Clarke, the lateral cervical nucleus (cat), the intermediolateral cell columns of the thoracic and upper lumbar levels, and selected groups of ventral horn neurons formed moderate to darkly reactive cell clusters, whereas fusiform and multipolar cells of Waldeyer in the marginal layer, small fusiform neurons in the ventral gray, funicular cells in the white matter, and ventral horn neurons of varying sizes tended to stand out against the neuropil as singly reactive neurons. At the electron microscopic level, reactive neurons were characterized by a greater packing density of darkly reactive mitochondria, while lightly reactive ones had fewer mitochondria, most of which showed very little reaction product. Reactive mitochondria were also found in the neuropil, mainly in dendritic profiles and some axon terminals. Glial cells, in general, were not very reactive. Ventral horn neurons from three macaque monkeys were measured for somatic areas and optical densities of cytochrome oxidase reaction product. A total of 1,770 neurons from representative sections of the cervical, thoracic, lumbar, and sacral cords of these animals were analyzed. The results indicated that the distribution of cell sizes as well as optical densities at every level of the cord fell on a continuum. Analysis of the regression coefficients revealed that the slopes were negative for all levels, indicating that there was a general inverse relationship between cell size and optical densities

  20. Reversal of neurochemical alterations in the spinal dorsal horn and dorsal root ganglia by Mas-related gene (Mrg) receptors in a rat model of spinal nerve injury.

    Science.gov (United States)

    Wang, Dongmei; Xue, Yaping; Yan, Yanhua; Lin, Minjie; Yang, Jiajia; Huang, Jianzhong; Hong, Yanguo

    2016-07-01

    The rodent Mas-related gene (Mrg) receptor subtype C has been demonstrated to inhibit pathological pain. This study investigated the mechanisms underlying the reversal of pain hypersensitivity by the selective MrgC receptor agonist bovine adrenal medulla 8-22 (BAM8-22) in a rat model of L5 spinal nerve ligation (SNL). Intrathecal (i.t.) administration of BAM8-22 (0.1-10nmol) attenuated mechanical allodynia in a dose-dependent manner on day 10 after SNL. The antiallodynia effect of BAM8-22 was abolished by MrgC receptor antibody, but not by naloxone. I.t. BAM8-22 (10nmol) inhibited SNL-induced upregulation of neuronal nitric oxide synthesis (nNOS) and phosphorylation of cyclic AMP response element-binding protein (p-CREB) in the spinal dorsal horn. The BAM8-22 treatment reversed the SNL-induced astrocyte activation, increase of interleukin-1β (IL-1β) expression and phosphorylation of extracellular signal-regulated kinase (p-ERK) in the spinal cord. BAM8-22 also reversed the upregulation of fractalkine and IL-1β in small- and medium-sized dorsal root ganglion (DRG) neurons. Furthermore, the BAM8-22 exposure suppressed the lipopolysaccharide (LPS)-induced increase of nNOS and IL-1β in the DRG explant cultures and the BAM8-22-induced suppression disappeared in the presence of MrgC receptor antibody. The present study provides evidence that activation of MrgC receptors inhibits nerve injury-induced increase of pronociceptive molecules in DRG neurons, suppressing astrocyte activation, the upregulation of excitatory mediators and phosphorylation of transcription factors in the spinal dorsal horn. As MrgC receptors are unequally expressed in the dorsal root and trigeminal ganglia, this study suggests that targeting MrgC receptors could be a new therapy for neuropathic pain with limited unwanted effects. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Immunofluorescence characterization of spinal cord dorsal horn microglia and astrocytes in horses

    OpenAIRE

    Meneses, Constanza Stefania; Müller, Heine Yacob; Herzberg, Daniel Eduardo; Uberti, Benjamín; Bustamante, Hedie Almagro; Werner, Marianne Patricia

    2017-01-01

    The role of glial cells in pain modulation has recently gathered attention. The objective of this study was to determine healthy spinal microglia and astrocyte morphology and disposition in equine spinal cord dorsal horns using Iba-1 and GFAP/Cx-43 immunofluorescence labeling, respectively. Five adult horses without visible wounds or gait alterations were selected. Spinal cord segments were obtained post-mortem for immunohistochemical and immunocolocalization assays. Immunodetection of spinal...

  2. 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.

  3. Central connectivity of transient receptor potential melastatin 8-expressing axons in the brain stem and spinal dorsal horn.

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    Yun Sook Kim

    Full Text Available Transient receptor potential melastatin 8 (TRPM8 ion channels mediate the detection of noxious and innocuous cold and are expressed by primary sensory neurons, but little is known about the processing of the TRPM8-mediated cold information within the trigeminal sensory nuclei (TSN and the spinal dorsal horn (DH. To address this issue, we characterized TRPM8-positive (+ neurons in the trigeminal ganglion and investigated the distribution of TRPM8+ axons and terminals, and their synaptic organization in the TSN and in the DH using light and electron microscopic immunohistochemistry in transgenic mice expressing a genetically encoded axonal tracer in TRPM8+ neurons. TRPM8 was expressed in a fraction of small myelinated primary afferent fibers (23.7% and unmyelinated fibers (76.3%, suggesting that TRPM8-mediated cold is conveyed via C and Aδ afferents. TRPM8+ axons were observed in all TSN, but at different densities in the dorsal and ventral areas of the rostral TSN, which dominantly receive sensory afferents from intra- and peri-oral structures and from the face, respectively. While synaptic boutons arising from Aδ and non-peptidergic C afferents usually receive many axoaxonic contacts and form complex synaptic arrangements, TRPM8+ boutons arising from afferents of the same classes of fibers showed a unique synaptic connectivity; simple synapses with one or two dendrites and sparse axoaxonic contacts. These findings suggest that TRPM8-mediated cold is conveyed via a specific subset of C and Aδ afferent neurons and is processed in a unique manner and differently in the TSN and DH.

  4. Central connectivity of transient receptor potential melastatin 8-expressing axons in the brain stem and spinal dorsal horn.

    Science.gov (United States)

    Kim, Yun Sook; Park, Jun Hong; Choi, Su Jung; Bae, Jin Young; Ahn, Dong Kuk; McKemy, David D; Bae, Yong Chul

    2014-01-01

    Transient receptor potential melastatin 8 (TRPM8) ion channels mediate the detection of noxious and innocuous cold and are expressed by primary sensory neurons, but little is known about the processing of the TRPM8-mediated cold information within the trigeminal sensory nuclei (TSN) and the spinal dorsal horn (DH). To address this issue, we characterized TRPM8-positive (+) neurons in the trigeminal ganglion and investigated the distribution of TRPM8+ axons and terminals, and their synaptic organization in the TSN and in the DH using light and electron microscopic immunohistochemistry in transgenic mice expressing a genetically encoded axonal tracer in TRPM8+ neurons. TRPM8 was expressed in a fraction of small myelinated primary afferent fibers (23.7%) and unmyelinated fibers (76.3%), suggesting that TRPM8-mediated cold is conveyed via C and Aδ afferents. TRPM8+ axons were observed in all TSN, but at different densities in the dorsal and ventral areas of the rostral TSN, which dominantly receive sensory afferents from intra- and peri-oral structures and from the face, respectively. While synaptic boutons arising from Aδ and non-peptidergic C afferents usually receive many axoaxonic contacts and form complex synaptic arrangements, TRPM8+ boutons arising from afferents of the same classes of fibers showed a unique synaptic connectivity; simple synapses with one or two dendrites and sparse axoaxonic contacts. These findings suggest that TRPM8-mediated cold is conveyed via a specific subset of C and Aδ afferent neurons and is processed in a unique manner and differently in the TSN and DH.

  5. Loss of calcineurin in the spinal dorsal horn contributes to neuropathic pain, and intrathecal administration of the phosphatase provides prolonged analgesia.

    Science.gov (United States)

    Miletic, Gordana; Lippitt, Jennifer A; Sullivan, Kristine M; Miletic, Vjekoslav

    2013-10-01

    Calcineurin (protein phosphatase 3) regulates synaptic plasticity in the brain. The development of neuropathic pain appears dependent on some of the same mechanisms that underlie brain synaptic plasticity. In this study, we examined whether calcineurin regulates chronic constriction injury (CCI)-elicited plasticity in the spinal dorsal horn. CCI animals exhibited mechanical and thermal hypersensitivity 7 days after ligation of the sciatic nerve. Neither control uninjured nor sham-operated animals exhibited pain behavior. Calcineurin activity and content of its Aα isoform were significantly decreased in the ipsilateral postsynaptic density (PSD) of dorsal horn neurons in CCI animals. Calcineurin activity and content in the contralateral PSD of CCI animals or either side of the dorsal horn in sham animals were not modified. The pain behavior in CCI animals was attenuated by intrathecal application of exogenous calcineurin. The treatment was long-lasting as a single injection provided analgesia for 4 days by restoring the phosphatase's activity and Aα content in the PSD. No signs of toxicity were detected up to 14 days after the single intrathecal injection. Intrathecal application of the calcineurin inhibitor FK-506 elicited pain behavior in control uninjured animals and significantly reduced calcineurin activity in the PSD. CCI may elicit neuropathic pain at least in part as a result of the loss of calcineurin-mediated dephosphorylation in the dorsal horn. Addition of the phosphatase by intrathecal injection reverses the injury-elicited loss and provides prolonged pain relief. Clinical therapy with calcineurin may prove to be a novel, effective, and safe approach in the management of well-established neuropathic pain. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  6. Central α-adrenoceptors contribute to mustard oil-induced central sensitization in the rat medullary dorsal horn.

    Science.gov (United States)

    Wang, H; Xie, Y F; Chiang, C Y; Dostrovsky, J O; Sessle, B J

    2013-04-16

    Our previous studies have demonstrated that application of the inflammatory irritant mustard oil (MO) to the tooth pulp produces trigeminal central sensitization that includes increases in mechanoreceptive field size and responses to noxious stimuli and decrease in activation threshold in brainstem nociceptive neurons of trigeminal subnucleus caudalis (the medullary dorsal horn, MDH). The aim of the present study was to test if central noradrenergic processes are involved in the central sensitization of MDH neurons and if α1-adrenoceptors or α2-adrenoceptors or both are involved. In urethane/α-chloralose-anesthetized rats, the activity of extracellularly recorded and functionally identified single nociceptive neurons in the MDH was studied. Continuous intrathecal (i.t.) superfusion of the adrenergic modulator guanethidine and α-adrenoceptor blocker phentolamine or selective α1-adrenoceptor antagonist prazosin over the medulla strongly attenuated all three MO-induced parameters of central sensitization in the MDH nociceptive neurons, compared to phosphate-buffered saline (as vehicle control). In contrast, i.t. superfusion of the selective α2-adrenoceptor antagonist yohimbine had little effect on the mechanoreceptive field expansion and the decreased mechanical activation threshold, and indeed facilitated responses to noxious stimuli of sensitized nociceptive neurons. Superfusion of each of the four chemicals alone did not affect baseline nociceptive neuronal properties. These findings provide the first documentation of the involvement of central noradrenergic processes in MDH in the development of the central sensitization, and that α1- and α2-adrenoceptors may be differentially involved. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Selective plasticity of primary afferent innervation to the dorsal horn and autonomic nuclei following lumbosacral ventral root avulsion and reimplantation in long term studies.

    Science.gov (United States)

    Wu, Lisa; Wu, Jun; Chang, Huiyi H; Havton, Leif A

    2012-02-01

    Previous studies involving injuries to the nerves of the cauda equina and the conus medullaris have shown that lumbosacral ventral root avulsion in rat models results in denervation and dysfunction of the lower urinary tract, retrograde and progressive cell death of the axotomized motor and parasympathetic neurons, as well as the emergence of neuropathic pain. Root reimplantation has also been shown to ameliorate several of these responses, but experiments thus far have been limited to studying the effects of lesion and reimplantation local to the lumbosacral region. Here, we have expanded the region of investigation after lumbosacral ventral root avulsion and reimplantation to include the thoracolumbar sympathetic region of the spinal cord. Using a retrograde tracer injected into the major pelvic ganglion, we were able to define the levels of the spinal cord that contain sympathetic preganglionic neurons innervating the lower urinary tract. We have conducted studies on the effects of the lumbosacral ventral root avulsion and reimplantation models on the afferent innervation of the dorsal horn and autonomic nuclei at both thoracolumbar and lumbosacral levels through immunohistochemistry for the markers calcitonin gene-related peptide (CGRP) and vesicular glutamate transporter 1 (VGLUT1). Surprisingly, our experiments reveal a selective and significant decrease of CGRP-positive innervation in the dorsal horn at thoracolumbar levels that is partially restored with root reimplantation. However, no similar changes were detected at the lumbosacral levels despite the injury and repair targeting efferent neurons, and being performed at the lumbosacral levels. Despite the changes evident in the thoracolumbar dorsal horn, we find no changes in afferent innervation of the autonomic nuclei at either sympathetic or parasympathetic segmental levels by CGRP or VGLUT1. We conclude that even remote, efferent root injuries and repair procedures can have an effect on remote and non

  8. 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...

  9. Inflammatory mediators potentiate high affinity GABA(A) currents in rat dorsal root ganglion neurons.

    Science.gov (United States)

    Lee, Kwan Yeop; Gold, Michael S

    2012-06-19

    Following acute tissue injury action potentials may be initiated in afferent processes terminating in the dorsal horn of the spinal cord that are propagated back out to the periphery, a process referred to as a dorsal root reflex (DRR). The DRR is dependent on the activation of GABA(A) receptors. The prevailing hypothesis is that DRR is due to a depolarizing shift in the chloride equilibrium potential (E(Cl)) following an injury-induced activation of the Na(+)-K(+)-Cl(-)-cotransporter. Because inflammatory mediators (IM), such as prostaglandin E(2) are also released in the spinal cord following tissue injury, as well as evidence that E(Cl) is already depolarized in primary afferents, an alternative hypothesis is that an IM-induced increase in GABA(A) receptor mediated current (I(GABA)) could underlie the injury-induced increase in DRR. To test this hypothesis, we explored the impact of IM (prostaglandin E(2) (1 μM), bradykinin (10 μM), and histamine (1 μM)) on I(GABA) in dissociated rat dorsal root ganglion (DRG) neurons with standard whole cell patch clamp techniques. IM potentiated I(GABA) in a subpopulation of medium to large diameter capsaicin insensitive DRG neurons. This effect was dependent on the concentration of GABA, manifest only at low concentrations (emergence of injury-induced DRR. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Identification of 5-HT receptor subtypes enhancing inhibitory transmission in the rat spinal dorsal horn in vitro.

    Science.gov (United States)

    Xie, Du-Jie; Uta, Daisuke; Feng, Peng-Yu; Wakita, Masahito; Shin, Min-Chul; Furue, Hidemasa; Yoshimura, Megumu

    2012-08-20

    5-hydroxytryptamine (5-HT) is one of the major neurotransmitters widely distributed in the CNS. Several 5-HT receptor subtypes have been identified in the spinal dorsal horn which act on both pre- and postsynaptic sites of excitatory and inhibitory neurons. However, the receptor subtypes and sites of actions as well as underlying mechanism are not clarified rigorously. Several electrophysiological studies have been performed to investigate the effects of 5-HT on excitatory transmission in substantia gelatinosa (SG) of the spinal cord. In the present study, to understand the effects of 5-HT on the inhibitory synaptic transmission and to identify receptor subtypes, the blind whole cell recordings were performed from SG neurons of rat spinal cord slices. Bath applied 5-HT (50 μM) increased the frequency but not amplitudes of spontaneous inhibitory postsynaptic currents (sIPSCs) in 58% of neurons, and both amplitude and frequency in 23% of neurons. The frequencies of GABAergic and glycinergic mIPSCs were both enhanced. TTX (0.5 μM) had no effect on the increasing frequency, while the enhancement of amplitude of IPSCs was eliminated. Evoked-IPSCs (eIPSCs) induced by focal stimulation near the recording neurons in the presence of CNQX and APV were enhanced in amplitude by 5-HT. In the presence of Ba(2+) (1 mM), a potassium channel blocker, 5-HT had no effect on both frequency and amplitude. A 5-HT(2A) receptor agonist, TCB-2 mimicked the 5-HT effect, and ketanserin, an antagonist of 5-HT(2A) receptor, inhibited the effect of 5-HT partially and TCB-2 almost completely. A 5-HT(2C) receptor agonist WAY 161503 mimicked the 5-HT effect and this effect was blocked by a 5-HT(2C) receptor antagonist, N-desmethylclozapine. The amplitudes of sIPSCs were unaffected by 5-HT(2A) or 5-HT(2C) agonists. A 5-HT(3) receptor agonist mCPBG enhanced both amplitude and frequency of sIPSCs. This effect was blocked by a 5-HT(3) receptor antagonist ICS-205,930. The perfusion of 5-HT(2B

  11. Upregulation of calcium channel alpha-2-delta-1 subunit in dorsal horn contributes to spinal cord injury-induced tactile allodynia.

    Science.gov (United States)

    Kusuyama, Kazuki; Tachibana, Toshiya; Yamanaka, Hiroki; Okubo, Masamichi; Yoshiya, Shinichi; Noguchi, Koichi

    2018-01-31

    -1 mRNAs in the lumbar spinal cord increased from Day 7 and continued for at least 28 days after SCI. Cellular analysis showed that SCI increased the number of α 2 δ-1-expressing cells in laminae I and II. The tactile allodynia of the hind paw in the SCI rats was reversed after pregabalin treatment and was maintained for 21 days. This administration of pregabalin decreased the α 2 δ-1 immunoreactivity significantly in the lumbar dorsal horn of thoracic SCI rats at 28 days after SCI. The present study results suggest that an increase of α 2 δ-1 in the L4 and L5 dorsal horns after thoracic SCI is derived from the increase in the expression in lumbar spinal neurons. This increase may be involved in the development of NeuP in the hind paws and the therapeutic effect of pregabalin on central NeuP after SCI. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Key role for spinal dorsal horn microglial kinin B1 receptor in early diabetic pain neuropathy

    Directory of Open Access Journals (Sweden)

    Couture Réjean

    2010-06-01

    Full Text Available Abstract Background The pro-nociceptive kinin B1 receptor (B1R is upregulated on sensory C-fibres, astrocytes and microglia in the spinal cord of streptozotocin (STZ-diabetic rat. This study aims at defining the role of microglial kinin B1R in diabetic pain neuropathy. Methods Sprague-Dawley rats were made diabetic with STZ (65 mg/kg, i.p., and 4 days later, two specific inhibitors of microglial cells (fluorocitrate, 1 nmol, i.t.; minocycline, 10 mg/kg, i.p. were administered to assess the impact on thermal hyperalgesia, allodynia and mRNA expression (qRT-PCR of B1R and pro-inflammatory markers. Spinal B1R binding sites ((125I-HPP-desArg10-Hoe 140 were also measured by quantitative autoradiography. Inhibition of microglia was confirmed by confocal microscopy with the specific marker Iba-1. Effects of intrathecal and/or systemic administration of B1R agonist (des-Arg9-BK and antagonists (SSR240612 and R-715 were measured on neuropathic pain manifestations. Results STZ-diabetic rats displayed significant tactile and cold allodynia compared with control rats. Intrathecal or peripheral blockade of B1R or inhibition of microglia reversed time-dependently tactile and cold allodynia in diabetic rats without affecting basal values in control rats. Microglia inhibition also abolished thermal hyperalgesia and the enhanced allodynia induced by intrathecal des-Arg9-BK without affecting hyperglycemia in STZ rats. The enhanced mRNA expression (B1R, IL-1β, TNF-α, TRPV1 and Iba-1 immunoreactivity in the STZ spinal cord were normalized by fluorocitrate or minocycline, yet B1R binding sites were reduced by 38%. Conclusion The upregulation of kinin B1R in spinal dorsal horn microglia by pro-inflammatory cytokines is proposed as a crucial mechanism in early pain neuropathy in STZ-diabetic rats.

  13. Key role for spinal dorsal horn microglial kinin B1 receptor in early diabetic pain neuropathy.

    Science.gov (United States)

    Talbot, Sébastien; Chahmi, Emna; Dias, Jenny Pena; Couture, Réjean

    2010-06-29

    The pro-nociceptive kinin B1 receptor (B1R) is upregulated on sensory C-fibres, astrocytes and microglia in the spinal cord of streptozotocin (STZ)-diabetic rat. This study aims at defining the role of microglial kinin B1R in diabetic pain neuropathy. Sprague-Dawley rats were made diabetic with STZ (65 mg/kg, i.p.), and 4 days later, two specific inhibitors of microglial cells (fluorocitrate, 1 nmol, i.t.; minocycline, 10 mg/kg, i.p.) were administered to assess the impact on thermal hyperalgesia, allodynia and mRNA expression (qRT-PCR) of B1R and pro-inflammatory markers. Spinal B1R binding sites ((125I)-HPP-desArg10-Hoe 140) were also measured by quantitative autoradiography. Inhibition of microglia was confirmed by confocal microscopy with the specific marker Iba-1. Effects of intrathecal and/or systemic administration of B1R agonist (des-Arg9-BK) and antagonists (SSR240612 and R-715) were measured on neuropathic pain manifestations. STZ-diabetic rats displayed significant tactile and cold allodynia compared with control rats. Intrathecal or peripheral blockade of B1R or inhibition of microglia reversed time-dependently tactile and cold allodynia in diabetic rats without affecting basal values in control rats. Microglia inhibition also abolished thermal hyperalgesia and the enhanced allodynia induced by intrathecal des-Arg9-BK without affecting hyperglycemia in STZ rats. The enhanced mRNA expression (B1R, IL-1beta, TNF-alpha, TRPV1) and Iba-1 immunoreactivity in the STZ spinal cord were normalized by fluorocitrate or minocycline, yet B1R binding sites were reduced by 38%. The upregulation of kinin B1R in spinal dorsal horn microglia by pro-inflammatory cytokines is proposed as a crucial mechanism in early pain neuropathy in STZ-diabetic rats.

  14. Stimulation-induced expression of immediate early gene proteins in the dorsal horn is increased in neuropathy.

    Science.gov (United States)

    Bojovic, Ognjen; Bramham, Clive R; Tjølsen, Arne

    2016-01-01

    Peripheral neuropathic pain is described as a pain state caused by an injury or dysfunction of the nervous system, and could have clinical manifestations such as hyperalgesia, allodynia and spontaneous pain. The development of neuropathic pain may depend on long-term forms of neuronal plasticity in the spinal cord (SC). Expression of the immediate early gene proteins (IEGPs) Arc, Zif268, and c-Fos are implicated in establishment of long-term potentiation (LTP) induced by conditioning stimulation (CS) of primary afferent fibres. However, the impact of the neuropathic state (Bennett's model) on CS-induced expression of IEGPs has not been studied. The aim of this study was to compare the levels of Arc, c-Fos and Zif268 immunoreactivity prior to and after conditioning stimulation in animals with developed neuropathic pain, with sham operated, non-ligated controls. Twenty-four animals were divided equally into the neuropathic and non-neuropathic groups. Neuropathic pain was induced in all animals by conducting a loose ligation of the sciatic nerve with Chromic Catgut 4.0 sutures 7 days prior to conditioning stimulation or sham operation. The loose ligation was performed by placing sutures around the sciatic nerve compressing the nerve slightly just enough to reduce but not completely diminish the perineural circulation. A state of neuropathy was confirmed by a significant decrease in mechanical withdrawal threshold measured by von Frey's fibres. Immunohistochemical analysis was performed on transverse sections obtained from the L3-L5 segments of the SC at 2 and 6h post-CS and IEGP positive cells were counted in lamina I and II of the dorsal horn. During statistical analyses, the groups were compared by means of analysis of variance (univariate general linear model). If significant differences were found, each set of animals was compared with the sham group with post hoc Tukey's multiple comparison test. Strikingly, all IEGPs exhibited a significant increase in

  15. Neonatal local noxious insult affects gene expression in the spinal dorsal horn of adult rats

    Directory of Open Access Journals (Sweden)

    Dubner Ronald

    2005-09-01

    Full Text Available Abstract Neonatal noxious insult produces a long-term effect on pain processing in adults. Rats subjected to carrageenan (CAR injection in one hindpaw within the sensitive period develop bilateral hypoalgesia as adults. In the same rats, inflammation of the hindpaw, which was the site of the neonatal injury, induces a localized enhanced hyperalgesia limited to this paw. To gain an insight into the long-term molecular changes involved in the above-described long-term nociceptive effects of neonatal noxious insult at the spinal level, we performed DNA microarray analysis (using microarrays containing oligo-probes for 205 genes encoding receptors and transporters for glutamate, GABA, and amine neurotransmitters, precursors and receptors for neuropeptides, and neurotrophins, cytokines and their receptors to compare gene expression profiles in the lumbar spinal dorsal horn (LDH of adult (P60 male rats that received neonatal CAR treatment within (at postnatal day 3; P3 and outside (at postnatal 12; P12 of the sensitive period. The data were obtained both without inflammation (at baseline and during complete Freund's adjuvant induced inflammation of the neonatally injured paw. The observed changes were verified by real-time RT-PCR. This study revealed significant basal and inflammation-associated aberrations in the expression of multiple genes in the LDH of adult animals receiving CAR injection at P3 as compared to their expression levels in the LDH of animals receiving either no injections or CAR injection at P12. In particular, at baseline, twelve genes (representing GABA, serotonin, adenosine, neuropeptide Y, cholecystokinin, opioid, tachykinin and interleukin systems were up-regulated in the bilateral LDH of the former animals. The baseline condition in these animals was also characterized by up-regulation of seven genes (encoding members of GABA, cholecystokinin, histamine, serotonin, and neurotensin systems in the LDH ipsilateral to the

  16. Rabies virus infection of cultured adult mouse dorsal root ganglion neurons

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    Jaime Castellanos

    1996-10-01

    Full Text Available An in vitro model of adult dorsal root ganglion neurons infection by rabies virus is described. Viral marked neurotropism is observed, and the percentage and the degree of infection of the neurons is higher than in non neuronal cells, even if neurons are the minority of the cells in the culture. The neuritic tree is also heavily infected by the virus.

  17. Neuronal types in the deep dorsal cochlear nucleus of the cat: I. Giant neurons.

    Science.gov (United States)

    Kane, E S; Puglisi, S G; Gordon, B S

    1981-05-20

    Large or "giant" neurons (average somatic diameter greater than 22 micron) of the dorsal cochlear nucleus (DCN) have been carefully described in this light (LM) and electron (EM) microscopic study of normal Nissl-stained and Golgi-impregnated cat brain stems. These neurons can be roughly classed by somatic shape (width:length ratio = r) as elongate (r less than 0.65), ovoid (0.65 less than or equal to r less than 0.75), or spherical (0.75 less than or equal to r less than or equal to 1.0) in Nissl-stained sections. However, orientation and location of somata, size, number, and distribution of basal dendrites and other cytological features seen in Nissl material provided five, easily recognized classes of large neurons: elongate bipolar, elongate multipolar, globular, radiate, and oriented multipolar giant cells. Further cytological details of the dendritic tree and axonal morphology of these neurons, observed in rapid Golgi impregnations of cat and kitten brain stems, extended these descriptive categories of giant neurons. These same deep DCN giant cells were identified in thick plastic sections and in subsequent thin sections. Thin sections showed further neuronal distinctions by relative density of somatic and dendritic synaptic inputs. All giant cells have dense synaptic inputs to basal and primary dendrites but only elongate multipolar and radiate giant cell somata have nearly continuous synaptic coverage of somata. Many axodendritic terminals and some axosomatic endings resemble cochlear endings as identified on fusiform cells of the DCN. Nauta preparations after ipsilateral cochlear ablations have confirmed (1) cochlear input to all giant cell types and (2) different patterns of input to each type. Hence, each giant cell type must process incoming auditory signals, but each cell must receive slightly different primary information. Since some giant cells of each type had observable axons heading into the dorsal acoustic stria, they must all carry encoded

  18. TRPA1 in the spinal dorsal horn is involved in post-inflammatory visceral hypersensitivity: in vivo study using TNBS-treated rat model

    Directory of Open Access Journals (Sweden)

    Li Q

    2016-12-01

    Full Text Available Qian Li,1,* Cheng-Hao Guo,2,* Mohammed Ali Chowdhury,1 Tao-Li Dai,1 Wei Han,1,3 1Department of Gastroenterology, Qilu Hospital of Shandong University, 2Department of Pathology, Medical School of Shandong University, 3Laboratory of Translational Gastroenterology, Shandong University, Qilu Hospital, Jinan, Shandong Province, People’s Republic of China *These authors contributed equally to this work Introduction: The transient receptor potential ankyrin-1 (TRPA1 channel, a pain transducer and amplifier, is drawing increasing attention in the field of visceral hypersensitivity, commonly seen in irritable bowel syndrome and inflammatory bowel disease. However, the role of TRPA1 in visceral nociception during post-inflammatory states is not well defined. Here, we explore the correlation between TRPA1 expression in the spinal dorsal horn (SDH and persistent post-inflammatory visceral hypersensitivity.Methods: We injected rats intracolonically with 2,4,6-trinitrobenzene sulfonic acid (TNBS or vehicle (n=12 per group. Post-inflammatory visceral hypersensitivity was assessed by recording the electromyographic activity of the external oblique muscle in response to colorectal distension. TRPA1 expression and distribution in the spinal cord and colon were examined by Western blotting and immunohistochemistry.Results: Animals exposed to TNBS had more abdominal contractions than vehicle-injected controls (P<0.05, which corresponded to a lower nociceptive threshold. Expression of TRPA1 in the SDH (especially in the substantia gelatinosa and the colon was significantly greater in the TNBS-treated group than in controls (P<0.05. In the SDH, the number of TRPA1-immunopositive neurons was 25.75±5.12 in the control group and 34.25±7.89 in the TNBS-treated group (P=0.023, and integrated optical density values of TRPA1 in the control and TNBS-treated groups were 14,544.63±6,525.54 and 22,532.75±7,608.11, respectively (P=0.041.Conclusion: Our results indicate

  19. [Effect of electroacupuncture on phosphorylation of NR2B at Tyr 1742 site in the spinal dorsal horn of CFA rats].

    Science.gov (United States)

    Liang, Yi; Fang, Jian-Qiao; Fang, Jun-Fan; Du, Jun-Ying; Qiu, Yu-Jie; Liu, Jin

    2013-10-01

    To observe the effect of electroacupuncture (EA) on phosphorylation of spinal NR2B at Tyr 1742 site in complete Freund's adjuvant (CFA) induced inflammatory pain rats. METHods Forty male Sprague Dawley rats were randomly divided into normal group (N group, n = 10), the model group (CFA group, n = 15), and the EA group (n = 15). The inflammatory pain model was established by subcutaneous injecting CFA (0.1 mL per rat) into the right hind paw. Paw withdrawal thresholds (PWTs) were measured before CFA injection (as the base), as well as at 24 h, 25 h, 3rd day, and 7th day after CFA injection. Phosphorylation of NR2B at Tyr 1742 site in the ispilateral spinal dorsal horn at the 3rd day post-injection were detected using immunohistochemical assay. PWTs in the CFA group were significantly lower than those of the N group at every detective time point post-injection (P CFA group at 25 h and 3rd day post-injection (P CFA group was up-regulated. Compared with the CFA group, the ratio of p-NR2B positive cells in the ispilateral spinal dorsal horn of rats showed a decreasing tendency in the EA group. EA might effectively inhibit CFA-induced inflammatory pain possibly associated with down-regulating phosphorylation of NR2B at Tyr 1742 site in the ispilateral spinal dorsal horn.

  20. The effect of intrathecal administration of glial activation inhibitors on dorsal horn BDNF overexpression and hind paw mechanical allodynia in spinal nerve ligated rats.

    Science.gov (United States)

    Zhang, Xin; Xu, Yongming; Wang, Jing; Zhou, Quanhong; Pu, Shaofeng; Jiang, Wei; Du, Dongping

    2012-03-01

    Recent studies have suggested that activated glia in the spinal cord may play a vital role at different times during spinal nerve ligation (SNL)-induced neuropathic pain; therefore, glial activation inhibitors have been used as effective painkillers. Brain-derived neurotrophic factor (BDNF) is also known to be a powerful pain modulator, but it remains unclear how it contributes to the glial activation inhibitor-based treatment. This study revealed the following results: (1) intrathecal administration of minocycline (a microglial activation inhibitor) could prevent mechanical allodynia during the initiation of SNL-induced neuropathic pain, and its action was associated with the elimination of BDNF overexpression in the dorsal horn; (2) the spinal injection of fluorocitrate (an astrocytic activation inhibitor) but not minocycline could reverse mechanical allodynia during the maintenance phase of SNL-induced pain, and its action was also related to a decrease in BDNF overexpression in the dorsal horn; and (3) treatment with TrkB/Fc (a BDNF-sequestering protein) had a similar effect during both the early development and maintenance periods. These results led to the following conclusions: (1) elevated BDNF expression in the dorsal horn was required to develop and maintain neuropathic pain; (2) minocycline could only prevent mechanical allodynia in the early stages, possibly by inhibiting BDNF release from microglia; and (3) fluorocitrate could reverse existing mechanical allodynia, and its action was associated with the inhibition of BDNF upregulation induced by astrocytic activation.

  1. Polysensory response characteristics of dorsal root ganglion neurones that may serve sensory functions during myocardial ischaemia.

    Science.gov (United States)

    Huang, M H; Horackova, M; Negoescu, R M; Wolf, S; Armour, J A

    1996-09-01

    To determine the response characteristics of dorsal root ganglion neurones that may serve sensory functions during myocardial ischaemia. Extracellular recordings were made from 54 spontaneously active and 5 normally quiescent dorsal root ganglion neurones (T2-T5) in 22 anaesthetized open-chest dogs under control conditions and during epicardial mechanical or chemical stimulation and myocardial ischaemia. The activity of 78% of spontaneously active and all quiescent neurones with left ventricular sensory fields was modified by left ventricular ischaemia. Forty-six spontaneously active neurones (85%) were polysensory with respect to mechanical and chemical stimuli. The 5 quiescent neurones responded only to chemical stimuli. Spontaneously active neurones associated with left ventricular mechanosensory endings (37 neurones) generated four different activity patterns in response to similar mechanical stimuli (high or low pressure active, high-low pressure active, high-low pressure inactive). A fifth group generated activity which was not related to chamber dynamics. Adenosine, adenosine 5'-triphosphate, substance P and bradykinin modified 72, 61, 65 and 63% of the spontaneously active neurones, respectively. Maximum local mechanical or chemical stimuli enhanced activity to similar degrees, as did ischaemia. Each ischaemia-sensitive neurone displayed unique activity patterns in response to similar mechanical or chemical stimuli. Most myocardial ischemia-sensitive dorsal root ganglion neurones associated with epicardial neurites sense mechanical and multiple chemical stimuli, a small population sensing only mechanical or chemical stimuli. Activity patterns generated by these neurones depend on their primary sensory characteristics or those of other neurones that may converge on them, as well as the type and magnitude of the stimuli that impinge upon their sensory fields, both normally and during ischaemia.

  2. Parvalbumin-Positive Neurons in Rat Dorsal Hippocampus Contain Muscarinic Acetylcholine Receptors

    NARCIS (Netherlands)

    Zee, E.A. van der; de Jong, Giena; Strosberg, A.D.; Luiten, P.G.M.

    1991-01-01

    The present study describes the colocalization of muscarinic acetylcholine receptors (mAChRs) and the calcium-binding protein parvalbumin (PARV) in nonpyramidal neurons of the rat dorsal hippocampus by means of dual-label immunocytochemistry. Fifty-two percent of all muscarinic cholinoceptive

  3. Coexistence of Muscarinic Acetylcholine Receptors and Somatostatin in Nonpyramidal Neurons of the Rat Dorsal Hippocampus

    NARCIS (Netherlands)

    Zee, E.A. van der; Benoit, R.; Strosberg, A.D.; Luiten, P.G.M.

    This study describes the colocalization of muscarinic acetylcholine receptors (mAChRs) and the neuropeptide somatostatin (SOM) in nonpyramidal neurons of the rat dorsal hippocampus. SOM and mAChRs were identified by immunocytochemistry employing antibody S309 and M35, respectively. Half of the

  4. Dorsal vagal preganglionic neurons: differential responses to CCK1 and 5-HT3 receptor stimulation.

    Science.gov (United States)

    Mussa, Bashair M; Sartor, Daniela M; Verberne, Anthony J M

    2010-08-25

    The dorsal motor nucleus of the vagus (DMV) is the main source of the vagal innervation of the pancreas. Several studies in vitro have demonstrated that the DMV consists of a heterogeneous population of preganglionic neurons but little is known about their electrophysiological characteristics in vivo. The aims of this study were to (i) identify DMV preganglionic neurons in vivo with axons in the pancreatic vagus and (ii) characterize their responses to stimulation of cholecystokinin (CCK(1)) and serotonin (5-HT(3)) receptors which are major regulators of pancreatic secretion. Male Sprague Dawley rats anaesthetised with isoflurane (1.5%/100% O(2)) were used throughout. Dorsal vagal preganglionic neurons were identified by antidromic activation in response to stimulation of the pancreatic vagus. Dorsal vagal preganglionic neurons had axonal conduction velocities in the C-fibre range (0.7+/-0.03 m/s). Forty-four neurons were identified within the rostral, intermediate and caudal DMV and thirty-eight were tested for responsiveness to CCK-8S (CCK(1) agonist) and phenylbiguanide (PBG; 5-HT(3) receptor agonist). CCK-8S and PBG (0.1-10 microg/kg, i.v.) produced three types of response: (i) preganglionic neurons in the intermediate DMV were inhibited by CCK-8S (n=18) and PBG (n=10), (ii) neurons in the caudal DMV were activated by CCK (n=5) and PBG (n=2) and (iii) CCK-8S (n=9) and PBG (n=7) had no effect on preganglionic neurons in the rostral DMV. CCK-8S and PBG have complex actions on preganglionic neurons in the DMV that may be related to their effects on pancreatic secretion. Copyright 2010 Elsevier B.V. All rights reserved.

  5. The homeodomain factor Gbx1 is required for locomotion and cell specification in the dorsal spinal cord

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    Hamid Meziane

    2013-08-01

    Full Text Available Dorsal horn neurons in the spinal cord integrate and relay sensory information to higher brain centers. These neurons are organized in specific laminae and different transcription factors are involved in their specification. The murine homeodomain Gbx1 protein is expressed in the mantle zone of the spinal cord at E12.5-13.5, correlating with the appearance of a discernable dorsal horn around E14 and eventually defining a narrow layer in the dorsal horn around perinatal stages. At postnatal stages, Gbx1 identifies a specific subpopulation of GABAergic neurons in the dorsal spinal cord. We have generated a loss of function mutation for Gbx1 and analyzed its consequences during spinal cord development. Gbx1−/− mice are viable and can reproduce as homozygous null mutants. However, the adult mutant mice display an altered gait during forward movement that specifically affects the hindlimbs. This abnormal gait was evaluated by a series of behavioral tests, indicating that locomotion is impaired, but not muscle strength or motor coordination. Molecular analysis showed that the development of the dorsal horn is not profoundly affected in Gbx1−/− mutant mice. However, analysis of terminal neuronal differentiation revealed that the proportion of GABAergic inhibitory interneurons in the superficial dorsal horn is diminished. Our study unveiled a role for Gbx1 in specifying a subset of GABAergic neurons in the dorsal horn of the spinal cord involved in the control of posterior limb movement.

  6. Differential transcriptional profiling of damaged and intact adjacent dorsal root ganglia neurons in neuropathic pain.

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    A K Reinhold

    Full Text Available Neuropathic pain, caused by a lesion in the somatosensory system, is a severely impairing mostly chronic disease. While its underlying molecular mechanisms are not thoroughly understood, neuroimmune interactions as well as changes in the pain pathway such as sensitization of nociceptors have been implicated. It has been shown that not only are different cell types involved in generation and maintenance of neuropathic pain, like neurons, immune and glial cells, but, also, intact adjacent neurons are relevant to the process. Here, we describe an experimental approach to discriminate damaged from intact adjacent neurons in the same dorsal root ganglion (DRG using differential fluorescent neuronal labelling and fluorescence-activated cell sorting (FACS. Two fluorescent tracers, Fluoroemerald (FE and 1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine perchlorate (DiI, were used, whose properties allow us to distinguish between damaged and intact neurons. Subsequent sorting permitted transcriptional analysis of both groups. Results and qPCR validation show a strong regulation in damaged neurons versus contralateral controls as well as a moderate regulation in adjacent neurons. Data for damaged neurons reveal an mRNA expression pattern consistent with established upregulated genes like galanin, which supports our approach. Moreover, novel genes were found strongly regulated such as corticotropin-releasing hormone (CRH, providing novel targets for further research. Differential fluorescent neuronal labelling and sorting allows for a clear distinction between primarily damaged neuropathic neurons and "bystanders," thereby facilitating a more detailed understanding of their respective roles in neuropathic processes in the DRG.

  7. Pulsed and continuous radiofrequency current adjacent to the cervical dorsal root ganglion of the rat induces late cellular activity in the dorsal horn.

    NARCIS (Netherlands)

    Zundert, J. van; Louw, A.J. de; Joosten, E.A.J.; Kessels, A.G.H.; Honig, W.; Dederen, P.J.W.C.; Veening, J.G.; Vles, J.S.; Kleef, M. van

    2005-01-01

    BACKGROUND: Pulsed radiofrequency treatment has recently been described as a non-neurodestructive or minimally neurodestructive alternative to radiofrequency heat lesions. In clinical practice long-lasting results of pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion for

  8. Allopregnanolone suppresses mechanical allodynia and internalization of neurokinin-1 receptors at the spinal dorsal horn in a rat postoperative pain model.

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    Fujita, Masahide; Fukuda, Taeko; Sato, Yasuhiro; Takasusuki, Toshifumi; Tanaka, Makoto

    2018-01-01

    To identify a new strategy for postoperative pain management, we investigated the analgesic effects of allopregnanolone (Allo) in an incisional pain model, and also assessed its effects on the activities of the primary afferent fibers at the dorsal horn. In experiment 1, 45 rats were assigned to Control, Allo small-dose (0.16 mg/kg), and Allo large-dose (1.6 mg/kg) groups (n = 15 in each). The weight bearing and mechanical withdrawal thresholds of the hind limb were measured before and at 2, 24, 48, and 168 h after Brennan's surgery. In experiment 2, 16 rats were assigned to Control and Allo (0.16 mg/kg) groups (n = 8 in each). The degree of spontaneous pain was measured using the grimace scale after the surgery. Activities of the primary afferent fibers in the spinal cord (L6) were evaluated using immunohistochemical staining. In experiment 1, the withdrawal threshold of the Allo small-dose group was significantly higher than that of the Control group at 2 h after surgery. Intergroup differences in weight bearing were not significant. In experiment 2, intergroup differences in the grimace scale scores were not significant. Substance P release in the Allo (0.16 mg/kg) group was significantly lower than that in the Control group. Systemic administration of Allo inhibited mechanical allodynia and activities of the primary afferent fibers at the dorsal horn in a rat postoperative pain model. Allo was proposed as a candidate for postoperative pain management.

  9. Dorsal Raphe Serotonin Neurons Mediate CO2-Induced Arousal from Sleep.

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    Smith, Haleigh R; Leibold, Nicole K; Rappoport, Daniel A; Ginapp, Callie M; Purnell, Benton S; Bode, Nicole M; Alberico, Stephanie L; Kim, Young-Cho; Audero, Enrica; Gross, Cornelius T; Buchanan, Gordon F

    2018-02-21

    Arousal from sleep in response to CO 2 is a critical protective phenomenon. Dysregulation of CO 2 -induced arousal contributes to morbidity and mortality from prevalent diseases, such as obstructive sleep apnea and sudden infant death syndrome. Despite the critical nature of this protective reflex, the precise mechanism for CO 2 -induced arousal is unknown. Because CO 2 is a major regulator of breathing, prevailing theories suggest that activation of respiratory chemo- and mechano-sensors is required for CO 2 -induced arousal. However, populations of neurons that are not involved in the regulation of breathing are also chemosensitive. Among these are serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) that comprise a component of the ascending arousal system. We hypothesized that direct stimulation of these neurons with CO 2 could cause arousal from sleep independently of enhancing breathing. Dialysis of CO 2 -rich acidified solution into DRN, but not medullary raphe responsible for modulating breathing, caused arousal from sleep. Arousal was lost in mice with a genetic absence of 5-HT neurons, and with acute pharmacological or optogenetic inactivation of DRN 5-HT neurons. Here we demonstrate that CO 2 can cause arousal from sleep directly, without requiring enhancement of breathing, and that chemosensitive 5-HT neurons in the DRN critically mediate this arousal. Better understanding mechanisms underlying this protective reflex may lead to interventions to reduce disease-associated morbidity and mortality. SIGNIFICANCE STATEMENT Although CO 2 -induced arousal is critical to a number of diseases, the specific mechanism is not well understood. We previously demonstrated that serotonin (5-HT) neurons are important for CO 2 -induced arousal, as mice without 5-HT neurons do not arouse to CO 2 Many have interpreted this to mean that medullary 5-HT neurons that regulate breathing are important in this arousal mechanism. Here we found that direct application of CO 2

  10. Research progress of dorsal root entry zone lesioning for the treatment of pain after brachial plexus avulsion

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    Qing-jun LIU

    2015-08-01

    Full Text Available Pain after brachial plexus avulsion (BPA is a clinically common drug-refractory neuropathic pain. Overactive spontaneous potential due to deafferentation in the neurons of spinal dorsal horn is the main pathogenesis of pain after BPA. Dorsal root entry zone (DREZ lesioning is one way that damages overactive spontaneous potential neurons in spinal dorsal horn through radio-frequency electrode or bipolar coagulation so as to achieve pain relief. Dorsal root entry zone lesioning is a safe and effective treatment approach for pain after BPA. DOI: 10.3969/j.issn.1672-6731.2015.08.014

  11. Loss of functional neuronal nicotinic receptors in dorsal root ganglion neurons in a rat model of neuropathic pain.

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    Dubé, Gilles R; Kohlhaas, Kathy L; Rueter, Lynne E; Surowy, Carol S; Meyer, Michael D; Briggs, Clark A

    2005-03-07

    Recent evidence has suggested that the anti-allodynic effect of neuronal acetylcholine receptor (nAChR) agonists may have a peripheral component [L.E. Rueter, K.L. Kohlhaas, P. Curzon, C.S. Surowy, M.D. Meyer, Peripheral and central sites of action for A-85380 in the spinal nerve ligation model of neuropathic pain, Pain 103 (2003) 269-276]. In further studies of the peripheral anti-allodynic mechanisms of nAChR agonists, we investigated the function of nAChRs in acutely isolated dorsal root ganglion (DRG) neurons from allodynic [L5-L6 spinal nerve ligation (SNL)] and naive adult rats. Following determination of cell diameter and membrane capacitance, responses to rapid applications of nAChR agonists were recorded under whole cell patch clamp. nAChR inward currents were observed in approximately 60% of naive neurons, across small, medium, and large diameter cells. Evoked nAChR currents could be clustered into three broad classes: fast transient, biphasic, and slow desensitizing currents, consistent with multiple subtypes of nAChR expressed in DRG [J.R. Genzen, W. Van Cleve, D.S. McGehee, Dorsal root ganglion neurons express multiple nicotinic acetylcholine receptor subtypes, J. Neurophysiol. 86 (2001) 1773-1782]. In contrast, in neurons from allodynic animals, the occurrence and amplitude of responses to nAChR agonists were significantly reduced. Reduced responsiveness to nAChR agonists covered the range of DRG neuron sizes. The decrease in the responsiveness to nAChR agonists was not seen in neighboring uninjured L4 neurons. The significant decrease in the number of cells with nAChR agonist responses, compounded with the significant decrease in response amplitude, indicates that there is a marked down regulation of functional nAChRs in DRG somata associated with SNL.

  12. Complex population response of dorsal putamen neurons predicts the ability to learn.

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    Laquitaine, Steeve; Piron, Camille; Abellanas, David; Loewenstein, Yonatan; Boraud, Thomas

    2013-01-01

    Day-to-day variability in performance is a common experience. We investigated its neural correlate by studying learning behavior of monkeys in a two-alternative forced choice task, the two-armed bandit task. We found substantial session-to-session variability in the monkeys' learning behavior. Recording the activity of single dorsal putamen neurons we uncovered a dual function of this structure. It has been previously shown that a population of neurons in the DLP exhibits firing activity sensitive to the reward value of chosen actions. Here, we identify putative medium spiny neurons in the dorsal putamen that are cue-selective and whose activity builds up with learning. Remarkably we show that session-to-session changes in the size of this population and in the intensity with which this population encodes cue-selectivity is correlated with session-to-session changes in the ability to learn the task. Moreover, at the population level, dorsal putamen activity in the very beginning of the session is correlated with the performance at the end of the session, thus predicting whether the monkey will have a "good" or "bad" learning day. These results provide important insights on the neural basis of inter-temporal performance variability.

  13. Membrane Mechanics of Primary Afferent Neurons in the Dorsal Root Ganglia of Rats.

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    Kanda, Hirosato; Gu, Jianguo G

    2017-04-25

    Membrane mechanics is an important biological factor regulating many cellular functions including cell motility, intercellular and intracellular signaling, gene expression, and membrane ion channel activity. Primary afferent neurons transduce sensory information about temperature, touch, and pain. These sensory functions may be profoundly affected by the states of primary afferent neuron mechanics. However, membrane mechanics of primary afferent neurons is largely unknown. In this study, we established the optical trapping technique for determining membrane mechanics of cultured primary afferent neurons of the dorsal root ganglia (DRG). We further determined the roles of cytoskeleton and membrane lipids in DRG neuron mechanics. We found that DRG neurons had a plasma membrane tension of ∼54 pN/μm, and the tension was significantly decreased to ∼29 pN/μm by cytochalasin D treatment to disrupt actin cytoskeleton and increased to ∼79 pN/μm by methyl-β-cyclodextrin treatment to sequester membrane cholesterol. DRG neuron membrane stiffness was not significantly affected by the cytoskeleton disruption but was significantly increased after cholesterol sequestration. Our findings elucidate membrane mechanical properties of primary afferent neurons, which provide, to our knowledge, a new perspective on their sensory functions. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  14. Modulation of AMPA excitatory postsynaptic currents in the spinal cord dorsal horn neurons by insulin

    Czech Academy of Sciences Publication Activity Database

    Špicarová, Diana; Paleček, Jiří

    2010-01-01

    Roč. 166, č. 1 (2010), s. 305-311 ISSN 0306-4522 R&D Projects: GA ČR(CZ) GA305/06/1115; GA ČR GA305/09/1228; GA MŠk(CZ) LC554 Institutional research plan: CEZ:AV0Z50110509 Keywords : pain * synaptic modulation * insulin Subject RIV: FH - Neurology Impact factor: 3.215, year: 2010

  15. Targeting dorsal root ganglia and primary sensory neurons for the treatment of chronic pain.

    Science.gov (United States)

    Berta, Temugin; Qadri, Yawar; Tan, Ping-Heng; Ji, Ru-Rong

    2017-07-01

    Currently the treatment of chronic pain is inadequate and compromised by debilitating central nervous system side effects. Here we discuss new therapeutic strategies that target dorsal root ganglia (DRGs) in the peripheral nervous system for a better and safer treatment of chronic pain. Areas covered: The DRGs contain the cell bodies of primary sensory neurons including nociceptive neurons. After painful injuries, primary sensory neurons demonstrate maladaptive molecular changes in DRG cell bodies and in their axons. These changes result in hypersensitivity and hyperexcitability of sensory neurons (peripheral sensitization) and are crucial for the onset and maintenance of chronic pain. We discuss the following new strategies to target DRGs and primary sensory neurons as a means of alleviating chronic pain and minimizing side effects: inhibition of sensory neuron-expressing ion channels such as TRPA1, TRPV1, and Nav1.7, selective blockade of C- and Aβ-afferent fibers, gene therapy, and implantation of bone marrow stem cells. Expert opinion: These peripheral pharmacological treatments, as well as gene and cell therapies, aimed at DRG tissues and primary sensory neurons can offer better and safer treatments for inflammatory, neuropathic, cancer, and other chronic pain states.

  16. Sodium salicylate suppresses GABAergic inhibitory activity in neurons of rodent dorsal raphe nucleus.

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    Yan Jin

    Full Text Available Sodium salicylate (NaSal, a tinnitus inducing agent, can activate serotonergic (5-HTergic neurons in the dorsal raphe nucleus (DRN and can increase serotonin (5-HT level in the inferior colliculus and the auditory cortex in rodents. To explore the underlying neural mechanisms, we first examined effects of NaSal on neuronal intrinsic properties and the inhibitory synaptic transmissions in DRN slices of rats by using whole-cell patch-clamp technique. We found that NaSal hyperpolarized the resting membrane potential, decreased the input resistance, and suppressed spontaneous and current-evoked firing in GABAergic neurons, but not in 5-HTergic neurons. In addition, NaSal reduced GABAergic spontaneous and miniature inhibitory postsynaptic currents in 5-HTergic neurons. We next examined whether the observed depression of GABAergic activity would cause an increase in the excitability of 5-HTergic neurons using optogenetic technique in DRN slices of the transgenic mouse with channelrhodopsin-2 expressed in GABAergic neurons. When the GABAergic inhibition was enhanced by optical stimulation to GABAergic neurons in mouse DRN, NaSal significantly depolarized the resting membrane potential, increased the input resistance and increased current-evoked firing of 5-HTergic neurons. However, NaSal would fail to increase the excitability of 5-HTergic neurons when the GABAergic synaptic transmission was blocked by picrotoxin, a GABA receptor antagonist. Our results indicate that NaSal suppresses the GABAergic activities to raise the excitability of local 5-HTergic neural circuits in the DRN, which may contribute to the elevated 5-HT level by NaSal in the brain.

  17. Sodium salicylate suppresses GABAergic inhibitory activity in neurons of rodent dorsal raphe nucleus.

    Science.gov (United States)

    Jin, Yan; Luo, Bin; Su, Yan-Yan; Wang, Xin-Xing; Chen, Liang; Wang, Ming; Wang, Wei-Wen; Chen, Lin

    2015-01-01

    Sodium salicylate (NaSal), a tinnitus inducing agent, can activate serotonergic (5-HTergic) neurons in the dorsal raphe nucleus (DRN) and can increase serotonin (5-HT) level in the inferior colliculus and the auditory cortex in rodents. To explore the underlying neural mechanisms, we first examined effects of NaSal on neuronal intrinsic properties and the inhibitory synaptic transmissions in DRN slices of rats by using whole-cell patch-clamp technique. We found that NaSal hyperpolarized the resting membrane potential, decreased the input resistance, and suppressed spontaneous and current-evoked firing in GABAergic neurons, but not in 5-HTergic neurons. In addition, NaSal reduced GABAergic spontaneous and miniature inhibitory postsynaptic currents in 5-HTergic neurons. We next examined whether the observed depression of GABAergic activity would cause an increase in the excitability of 5-HTergic neurons using optogenetic technique in DRN slices of the transgenic mouse with channelrhodopsin-2 expressed in GABAergic neurons. When the GABAergic inhibition was enhanced by optical stimulation to GABAergic neurons in mouse DRN, NaSal significantly depolarized the resting membrane potential, increased the input resistance and increased current-evoked firing of 5-HTergic neurons. However, NaSal would fail to increase the excitability of 5-HTergic neurons when the GABAergic synaptic transmission was blocked by picrotoxin, a GABA receptor antagonist. Our results indicate that NaSal suppresses the GABAergic activities to raise the excitability of local 5-HTergic neural circuits in the DRN, which may contribute to the elevated 5-HT level by NaSal in the brain.

  18. Neurochemical differences between target-specific populations of rat dorsal raphe projection neurons.

    Science.gov (United States)

    Prouty, Eric W; Chandler, Daniel J; Waterhouse, Barry D

    2017-11-15

    Serotonin (5-HT)-containing neurons in the dorsal raphe (DR) nucleus project throughout the forebrain and are implicated in many physiological processes and neuropsychiatric disorders. Diversity among these neurons has been characterized in terms of their neurochemistry and anatomical organization, but a clear sense of whether these attributes align with specific brain functions or terminal fields is lacking. DR 5-HT neurons can co-express additional neuroactive substances, increasing the potential for individualized regulation of target circuits. The goal of this study was to link DR neurons to a specific functional role by characterizing cells according to both their neurotransmitter expression and efferent connectivity; specifically, cells projecting to the medial prefrontal cortex (mPFC), a region implicated in cognition, emotion, and responses to stress. Following retrograde tracer injection, brainstem sections from Sprague-Dawley rats were immunohistochemically stained for markers of serotonin, glutamate, GABA, and nitric oxide (NO). 98% of the mPFC-projecting serotonergic neurons co-expressed the marker for glutamate, while the markers for NO and GABA were observed in 60% and less than 1% of those neurons, respectively. To identify potential target-specific differences in co-transmitter expression, we also characterized DR neurons projecting to a visual sensory structure, the lateral geniculate nucleus (LGN). The proportion of serotonergic neurons co-expressing NO was greater amongst cells targeting the mPFC vs LGN (60% vs 22%). The established role of 5-HT in affective disorders and the emerging role of NO in stress signaling suggest that the impact of 5-HT/NO co-localization in DR neurons that regulate mPFC circuit function may be clinically relevant. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Isolated dorsal root ganglion neurones inhibit receptor-dependent adenylyl cyclase activity in associated glial cells

    Science.gov (United States)

    Ng, KY; Yeung, BHS; Wong, YH; Wise, H

    2013-01-01

    Background and Purpose Hyper-nociceptive PGE2 EP4 receptors and prostacyclin (IP) receptors are present in adult rat dorsal root ganglion (DRG) neurones and glial cells in culture. The present study has investigated the cell-specific expression of two other Gs-protein coupled hyper-nociceptive receptor systems: β-adrenoceptors and calcitonin gene-related peptide (CGRP) receptors in isolated DRG cells and has examined the influence of neurone–glial cell interactions in regulating adenylyl cyclase (AC) activity. Experimental Approach Agonist-stimulated AC activity was determined in mixed DRG cell cultures from adult rats and compared with activity in DRG neurone-enriched cell cultures and pure DRG glial cell cultures. Key Results Pharmacological analysis showed the presence of Gs-coupled β2-adrenoceptors and CGRP receptors, but not β1-adrenoceptors, in all three DRG cell preparations. Agonist-stimulated AC activity was weakest in DRG neurone-enriched cell cultures. DRG neurones inhibited IP receptor-stimulated glial cell AC activity by a process dependent on both cell–cell contact and neurone-derived soluble factors, but this is unlikely to involve purine or glutamine receptor activation. Conclusions and Implications Gs-coupled hyper-nociceptive receptors are readily expressed on DRG glial cells in isolated cell cultures and the activity of CGRP, EP4 and IP receptors, but not β2-adrenoceptors, in glial cells is inhibited by DRG neurones. Studies using isolated DRG cells should be aware that hyper-nociceptive ligands may stimulate receptors on glial cells in addition to neurones, and that variable numbers of neurones and glial cells will influence absolute measures of AC activity and affect downstream functional responses. PMID:22924655

  20. Extrasynaptic glycine receptors of rodent dorsal raphe serotonergic neurons: a sensitive target for ethanol.

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    Maguire, Edward P; Mitchell, Elizabeth A; Greig, Scott J; Corteen, Nicole; Balfour, David J K; Swinny, Jerome D; Lambert, Jeremy J; Belelli, Delia

    2014-04-01

    Alcohol abuse is a significant medical and social problem. Several neurotransmitter systems are implicated in ethanol's actions, with certain receptors and ion channels emerging as putative targets. The dorsal raphe (DR) nucleus is associated with the behavioral actions of alcohol, but ethanol actions on these neurons are not well understood. Here, using immunohistochemistry and electrophysiology we characterize DR inhibitory transmission and its sensitivity to ethanol. DR neurons exhibit inhibitory 'phasic' post-synaptic currents mediated primarily by synaptic GABAA receptors (GABAAR) and, to a lesser extent, by synaptic glycine receptors (GlyR). In addition to such phasic transmission mediated by the vesicular release of neurotransmitter, the activity of certain neurons may be governed by a 'tonic' conductance resulting from ambient GABA activating extrasynaptic GABAARs. However, for DR neurons extrasynaptic GABAARs exert only a limited influence. By contrast, we report that unusually the GlyR antagonist strychnine reveals a large tonic conductance mediated by extrasynaptic GlyRs, which dominates DR inhibition. In agreement, for DR neurons strychnine increases their input resistance, induces membrane depolarization, and consequently augments their excitability. Importantly, this glycinergic conductance is greatly enhanced in a strychnine-sensitive fashion, by behaviorally relevant ethanol concentrations, by drugs used for the treatment of alcohol withdrawal, and by taurine, an ingredient of certain 'energy drinks' often imbibed with ethanol. These findings identify extrasynaptic GlyRs as critical regulators of DR excitability and a novel molecular target for ethanol.

  1. Glutamatergic neurotransmission between the C1 neurons and the parasympathetic preganglionic neurons of the dorsal motor nucleus of the vagus

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    DePuy, Seth D.; Stornetta, Ruth L.; Bochorishvili, Genrieta; Deisseroth, Karl; Witten, Ilana; Coates, Melissa; Guyenet, Patrice G.

    2013-01-01

    Summary The C1 neurons are a nodal point for blood pressure control and other autonomic responses. Here we test whether these rostral ventrolateral medullary catecholaminergic (RVLM-CA) neurons use glutamate as a transmitter in the dorsal motor nucleus of the vagus (DMV). After injecting Cre-dependent AAV2 DIO-Ef1α-channelrhodopsin2(ChR2)-mCherry (AAV2) into the RVLM of dopamine-beta-hydroxylase Cre transgenic mice (DβHCre/0), mCherry was detected exclusively in RVLM-CA neurons. Within the DMV >95% mCherry-immunoreactive (-ir) axonal varicosities were tyrosine hydroxylase-ir and the same proportion were vesicular glutamate transporter 2 (VGLUT2)-ir. VGLUT2-mCherry co-localization was virtually absent when AAV2 was injected into the RVLM of DβHCre/0;VGLUT2flox/flox mice, into the caudal VLM (A1 noradrenergic neuron-rich region) of DβHCre/0 mice or into the raphe of ePetCre/0 mice. Following injection of AAV2 into RVLM of TH-Cre rats, phenylethanolamine N-methyl transferase (PNMT) and VGLUT2 immunoreactivities were highly co-localized in DMV within EYFP-positive or EYFP-negative axonal varicosities. Ultrastructurally, mCherry terminals from RVLM-CA neurons in DβHCre/0 mice made predominantly asymmetric synapses with ChAT-ir DMV neurons. Photostimulation of ChR2-positive axons in DβHCre/0 mouse brain slices produced EPSCs in 71% of tested DMV preganglionic neurons (PGNs) but no IPSCs. Photostimulation (20 Hz) activated PGNs up to 8 spikes/sec (current clamp). EPSCs were eliminated by tetrodotoxin, reinstated by 4-aminopyridine and blocked by ionotropic glutamate receptor blockers. In conclusion, VGLUT2 is expressed by RVLM-CA (C1) neurons in rats and mice regardless of the presence of AAV2, the C1 neurons activate DMV parasympathetic preganglionic neurons monosynaptically and this connection uses glutamate as an ionotropic transmitter. PMID:23345223

  2. “Three Methods and Three Points” regulates p38 mitogen-activated protein kinase in the dorsal horn of the spinal cord in a rat model of sciatic nerve injury

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    Xin Guo

    2016-01-01

    Full Text Available Tuina is a traditional Chinese treatment for sensory disturbances caused by peripheral nerve injury and related diseases. Our previous studies showed that tuina regulates relevant regions and indices of the spinal dorsal horn using the Dian, Bo, and Rou method in Yinmen (BL37, Yanglingquan (GB34, and Weizhong (BL40. Treatment prevents muscle atrophy, protects spinal cord neurons, and promotes sciatic nerve repair. The mechanisms of action of tuina for treating peripheral nerve injury remain poorly understood. This study established rat models of sciatic nerve injury using the crushing method. Rats received Chinese tuina in accordance with the principle of “Three Methods and Three Points,” once daily for 20 days. Tuina intervention reduced paw withdrawal latency and improved wet weight of the gastrocnemius muscle, as well as promoting morphological recovery of sciatic nerve fibers, Schwann cells, and axons. The protein expression levels of phospho-p38 mitogen-activated protein kinase, tumor necrosis factor-α, and interleukin-1β also decreased. These findings indicate that “Three Methods and Three Points” promoted morphological recovery and improved behavior of rats with peripheral nerve injury.

  3. Impaired chemosensitivity of mouse dorsal raphe serotonergic neurons overexpressing serotonin 1A (Htr1a) receptors.

    Science.gov (United States)

    Baccini, Gilda; Mlinar, Boris; Audero, Enrica; Gross, Cornelius Thilo; Corradetti, Renato

    2012-01-01

    Serotonergic system participates in a wide range of physiological processes and behaviors, but its role is generally considered as modulatory and noncrucial, especially concerning life-sustaining functions. We recently created a transgenic mouse line in which a functional deficit in serotonin homeostasis due to excessive serotonin autoinhibition was produced by inducing serotonin 1A receptor (Htr1a) overexpression selectively in serotonergic neurons (Htr1a raphe-overexpressing or Htr1a(RO) mice). Htr1a(RO) mice exhibit episodes of autonomic dysregulation, cardiovascular crises and death, resembling those of sudden infant death syndrome (SIDS) and revealing a life-supporting role of serotonergic system in autonomic control. Since midbrain serotonergic neurons are chemosensitive and are implicated in arousal we hypothesized that their chemosensitivity might be impaired in Htr1a(RO) mice. Loose-seal cell-attached recordings in brainstem slices revealed that serotonergic neurons in dorsal raphe nucleus of Htr1a(RO) mice have dramatically reduced responses to hypercapnic challenge as compared with control littermates. In control mice, application of 9% CO(2) produced an increase in firing rate of serotonergic neurons (0.260 ± 0.041 Hz, n=20, p=0.0001) and application of 3% CO(2) decreased their firing rate (-0.142 ± 0.025 Hz, n=17, p=0.0008). In contrast, in Htr1a(RO) mice, firing rate of serotonergic neurons was not significantly changed by 9% CO(2) (0.021 ± 0.034 Hz, n=16, p=0.49) and by 3% CO(2) (0.012 ± 0.046 Hz, n=12, p=0.97). Our findings support the hypothesis that chemosensitivity of midbrain serotonergic neurons provides a physiological mechanism for arousal responses to life-threatening episodes of hypercapnia and that functional impairment, such as excessive autoinhibition, of midbrain serotonergic neuron responses to hypercapnia may contribute to sudden death.

  4. Serotonergic versus Nonserotonergic Dorsal Raphe Projection Neurons: Differential Participation in Reward Circuitry

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    Ross A. McDevitt

    2014-09-01

    Full Text Available The dorsal raphe nucleus (DRN contains the largest group of serotonin-producing neurons in the brain and projects to regions controlling reward. Although pharmacological studies suggest that serotonin inhibits reward seeking, electrical stimulation of the DRN strongly reinforces instrumental behavior. Here, we provide a targeted assessment of the behavioral, anatomical, and electrophysiological contributions of serotonergic and nonserotonergic DRN neurons to reward processes. To explore DRN heterogeneity, we used a simultaneous two-vector knockout/optogenetic stimulation strategy, as well as cre-induced and cre-silenced vectors in several cre-expressing transgenic mouse lines. We found that the DRN is capable of reinforcing behavior primarily via nonserotonergic neurons, for which the main projection target is the ventral tegmental area (VTA. Furthermore, these nonserotonergic projections provide glutamatergic excitation of VTA dopamine neurons and account for a large majority of the DRN-VTA pathway. These findings help to resolve apparent discrepancies between the roles of serotonin versus the DRN in behavioral reinforcement.

  5. Neuropeptide FF receptors exhibit direct and anti-opioid effects on mice dorsal raphe nucleus neurons.

    Science.gov (United States)

    Ding, Zhong; Zajac, Jean-Marie

    2014-10-05

    By using acutely dissociated dorsal raphe nucleus neurons (DRN) from young mice, direct and anti-opioid effects of Neuropeptide FF (NPFF) receptors were measured. The NPFF analog 1 DMe (10 µM) had no effect on resting Ca2+ channels but reduced the magnitude of Ca2+ transients induced by depolarization in 83.3% neurons tested, of which the inhibition rate is 45.4±2.9%. Pertussis toxin treatment reduced to 18.9% the number of responding neurons and attenuated by 47% the response of 1 DMe. In contrast, cholera toxin treatment had no significant effect. Eighteen minute perfusion with 1 DMe at a very low 10 nM concentration, that did not directly inhibit Ca2+ transients triggered by depolarization in every neuron, attenuated by 78% the inhibitory effect of Nociceptin/orphanin FQ (N/OFQ) on Ca2+ transients, but not that of by serotonin. These results demonstrated for the first time that NPFF receptors on mice DRN inhibit Ca2+ transients induced by depolarization via Gi/o protein and also exhibit a specific anti-opioid activity on nociceptin receptors, and that their specific anti-opioid activity is not a direct consequence of their activity on Ca2+ transients. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Effects of substance P on identified neurons of the rat dorsal motor nucleus of the vagus.

    Science.gov (United States)

    Lewis, M W; Travagli, R A

    2001-07-01

    Previous evidence suggests that substance P (SP) activates subpopulations of neurons within the dorsal motor nucleus of the vagus (DMV). In this study we aimed at identifying these subpopulations in relation to their gastrointestinal projection organs or vagal branches and characterizing pharmacologically the SP response. Using whole cell patch-clamp recordings from identified gastrointestinal-projecting vagal motoneurons, we found that SP induced an inward current in all neuronal groups except for cecum-projecting cells. The lowest percentage of SP-responding neurons was found in fundus-projecting cells, where SP also had a concentration-response curve that was shifted to the left (P < 0.05). Independently from the projections, the SP response was reduced by sendide and MEN 10,376 and mimicked by a combination of [Sar(9)-Met(O(2))(11)]SP and alpha-neurokinin. SP and alpha-neurokinin also increased the frequency, but not the amplitude, of postsynaptic currents. In conclusion, we demonstrated that SP induces both pre- and postsynaptic effects on DMV neurons via activation of neurokinin NK(1) and NK(2) receptors. The magnitude of the SP response was correlated to the peripheral target organ.

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

    Science.gov (United States)

    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.

  8. Anterograde glycoprotein-dependent transport of newly generated rabies virus in dorsal root ganglion neurons.

    Science.gov (United States)

    Bauer, Anja; Nolden, Tobias; Schröter, Josephine; Römer-Oberdörfer, Angela; Gluska, Shani; Perlson, Eran; Finke, Stefan

    2014-12-01

    Rabies virus (RABV) spread is widely accepted to occur only by retrograde axonal transport. However, examples of anterograde RABV spread in peripheral neurons such as dorsal root ganglion (DRG) neurons indicated a possible bidirectional transport by an uncharacterized mechanism. Here, we analyzed the axonal transport of fluorescence-labeled RABV in DRG neurons by live-cell microscopy. Both entry-related retrograde transport of RABV after infection at axon endings and postreplicative transport of newly formed virus were visualized in compartmentalized DRG neuron cultures. Whereas entry-related transport at 1.5 μm/s occurred only retrogradely, after 2 days of infection, multiple particles were observed in axons moving in both the anterograde and retrograde directions. The dynamics of postreplicative retrograde transport (1.6 μm/s) were similar to those of entry-related retrograde transport. In contrast, anterograde particle transport at 3.4 μm/s was faster, indicating active particle transport. Interestingly, RABV missing the glycoproteins did not move anterogradely within the axon. Thus, anterograde RABV particle transport depended on the RABV glycoprotein. Moreover, colocalization of green fluorescent protein (GFP)-labeled ribonucleoproteins (RNPs) and glycoprotein in distal axonal regions as well as cotransport of labeled RNPs with membrane-anchored mCherry reporter confirmed that either complete enveloped virus particles or vesicle associated RNPs were transported. Our data show that anterograde RABV movement in peripheral DRG neurons occurs by active motor protein-dependent transport. We propose two models for postreplicative long-distance transport in peripheral neurons: either transport of complete virus particles or cotransport of RNPs and G-containing vesicles through axons to release virus at distal sites of infected DRG neurons. Rabies virus retrograde axonal transport by dynein motors supports virus spread over long distances and lethal infection of

  9. Dync1h1 Mutation Causes Proprioceptive Sensory Neuron Loss and Impaired Retrograde Axonal Transport of Dorsal Root Ganglion Neurons.

    Science.gov (United States)

    Zhao, Jing; Wang, Yi; Xu, Huan; Fu, Yuan; Qian, Ting; Bo, Deng; Lu, Yan-Xin; Xiong, Yi; Wan, Jun; Zhang, Xiang; Dong, Qiang; Chen, Xiang-Jun

    2016-07-01

    Sprawling (Swl) is a radiation-induced mutation which has been identified to have a nine base pair deletion in dynein heavy chain 1 (DYNC1H1: encoded by a single gene Dync1h1). This study is to investigate the phenotype and the underlying mechanism of the Dync1h1 mutant. To display the phenotype of Swl mutant mice, we examined the embryos of homozygous (Swl/Swl) and heterozygous (Swl/+) mice and their postnatal dorsal root ganglion (DRG) of surviving Swl/+ mice. The Swl/+ mice could survive for a normal life span, while Swl/Swl could only survive till embryonic (E) 8.5 days. Excessive apoptosis of Swl/+ DRG neurons was revealed during E11.5-E15.5 days, and the peak rate was at E13.5 days. In vitro study of mutated DRG neurons showed impaired retrograde transport of dynein-driven nerve growth factor (NGF). Mitochondria, another dynein-driven cargo, demonstrated much slower retrograde transport velocity in Swl/+ neurons than in wild-type (WT) neurons. Nevertheless, the Swl, Loa, and Cra mutations did not affect homodimerization of DYNC1H1. The Swl/Swl mutation of Dync1h1 gene led to embryonic mal-development and lethality, whereas the Swl/+ DRG neurons demonstrated deficient retrograde transport in dynein-driven cargos and excessive apoptosis during mid- to late-developmental stages. The underlying mechanism of the mutation may not be due to impaired homodimerization of DYNC1H1. © 2016 John Wiley & Sons Ltd.

  10. Biophysical properties and computational modeling of calcium spikes in serotonergic neurons of the dorsal raphe nucleus.

    Science.gov (United States)

    Tuckwell, Henry C

    2013-06-01

    Serotonergic neurons of the dorsal raphe nuclei, with their extensive innervation of nearly the whole brain have important modulatory effects on many cognitive and physiological processes. They play important roles in clinical depression and other psychiatric disorders. In order to quantify the effects of serotonergic transmission on target cells it is desirable to construct computational models and to this end these it is necessary to have details of the biophysical and spike properties of the serotonergic neurons. Here several basic properties are reviewed with data from several studies since the 1960s to the present. The quantities included are input resistance, resting membrane potential, membrane time constant, firing rate, spike duration, spike and afterhyperpolarization (AHP) amplitude, spike threshold, cell capacitance, soma and somadendritic areas. The action potentials of these cells are normally triggered by a combination of sodium and calcium currents which may result in autonomous pacemaker activity. We here analyse the mechanisms of high-threshold calcium spikes which have been demonstrated in these cells the presence of TTX (tetrodotoxin). The parameters for calcium dynamics required to give calcium spikes are quite different from those for regular spiking which suggests the involvement of restricted parts of the soma-dendritic surface as has been found, for example, in hippocampal neurons. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Depression of presynaptic excitation by the activation of vanilloid receptor 1 in the rat spinal dorsal horn revealed by optical imaging

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    Ikeda Hiroshi

    2006-02-01

    Full Text Available Abstract In this study, we show that capsaicin (CAP depresses primary afferent fiber terminal excitability by acting on vanilloid receptor 1 (TRPV1 channels of primary afferent fibers in adenosine 5'-triphosphate (ATP- and temperature-dependent manner using two optical imaging methods. First, transverse slices of spinal cord were stained with a voltage-sensitive dye and the net excitation in the spinal dorsal horn was recorded. Prolonged treatment (>20 min with the TRPV1 channel agonist, CAP, resulted in a long-lasting inhibition of the net excitation evoked by single-pulse stimulation of C fiber-activating strength. A shorter application of CAP inhibited the excitation in a concentration-dependent manner and the inhibition was reversed within several minutes. This inhibition was Ca++-dependent, was antagonized by the TRPV1 channel antagonist, capsazepine (CPZ, and the P2X and P2Y antagonist, suramin, and was facilitated by the P2Y agonist, uridine 5'-triphosphate (UTP. The inhibition of excitation was unaffected by bicuculline and strychnine, antagonists of GABAA and glycine receptors, respectively. Raising the perfusate temperature to 39°C from 27°C inhibited the excitation (-3%/°C. This depressant effect was antagonized by CPZ and suramin, but not by the P2X antagonist, 2', 3'-O-(2,4,6-trinitrophenyl adenosine 5'-triphosphate (TNP-ATP. Second, in order to record the presynaptic excitation exclusively, we stained the primary afferent fibers anterogradely from the dorsal root. CAP application and a temperature increase from 27°C to 33°C depressed the presynaptic excitation, and CPZ antagonized these effects. Thus, this study showed that presynaptic excitability is modulated by CAP, temperature, and ATP under physiological conditions, and explains the reported central actions of CAP. These results may have clinical importance, especially for the control of pain.

  12. Therapeutic effect of Tat-LK15-mediated the interference of siRNA with nNOS expression in the spinal dorsal horn on neuropathic pain in rats

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    Yun RAO

    2017-10-01

    Full Text Available Objective To investigate the therapeutic effect of cell penetrating peptide Tat-LK15 mediating small interfering RNA (siRNA interference with the expression of neuronal nitric oxide synthase (nNOS in rat spinal dorsal horn on neuropathic pain. Methods The transfection reagent, Tat-LK15, was used to mediate the transfection of rat spinal dorsal horn (SDH neuronal cells with carboxyfluorescein (FAM, and then the transfection effect was observed under inverted fluorescence microscope. Fifty healthy male SD rats were randomly divided into 5 groups (n=10: control group, sham operation group (sham group, neuropathic pain group (SNL group, Tat-LK15-nNOS siRNA group (TS group and Tat-LK15-NC siRNA group (TN group. Neuropathic pain was induced by spinal nerve ligation (SNL, rats in control group did not receive operation and only the spinal nerve was exposed in sham group. Groups SNL, TS and TN were made into the models by SNL and implanted intrathecal catheter, intrathecal administration was performed from the 7th day after model establishment, and 10μl normal saline, 10μl TS complex (including 5μg siRNA and 10μl TN (including 5μg siRNA were injected intrathecally each day for 7 days. Paw withdrawal mechanical threshold (PWMT and paw withdrawal thermal latency (PWTL were measured at 1 day before (baseline and 3, 7, 10 and 14 days after model establishment. Then animals were sacrificed on the 14th day after the operation and the lumbar segment (L4-6 of the spinal cord was removed to detect the expressions of nNOS mRNA and protein using q-PCR and Western blotting analysis. Results Tat-LK15 effectively mediated FAM-siRNA into SDH neuronal cells. Compared with sham group, SNL significantly decreased PWMT and PWTL and increased expressions of nNOS mRNA and protein from the 3rd day (P<0.01, but there was no significant difference between the sham and control group. Tat-LK15-nNOS siRNA complex significantly increased PWMT and PWTL and down-regulated n

  13. Neonatal intraperitoneal or intravenous injections of recombinant adeno-associated virus type 8 transduce dorsal root ganglia and lower motor neurons.

    Science.gov (United States)

    Foust, Kevin D; Poirier, Amy; Pacak, Christina A; Mandel, Ronald J; Flotte, Terence R

    2008-01-01

    Targeting lower motor neurons (LMNs) for gene delivery could be useful for disorders such as spinal muscular atrophy and amyotrophic lateral sclerosis. LMNs reside in the ventral gray matter of the spinal cord and send axonal projections to innervate skeletal muscle. Studies have used intramuscular injections of adeno-associated virus type 2 (AAV2) to deliver viral vectors to LMNs via retrograde transport. However, treating large areas of the spinal cord in a human would require numerous intramuscular injections, thereby increasing viral titer and risk of immune response. New AAV serotypes, such as AAV8, have a dispersed transduction pattern after intravenous or intraperitoneal injection in neonatal mice, and may transduce LMNs by retrograde transport or through entry into the nervous system. To test LMN transduction after systemic injection, we administered recombinant AAV8 (rAAV8) carrying the green fluorescent protein (GFP) gene by intravenous or intraperitoneal injection to neonatal mice on postnatal day 1. Tissues were harvested 5 and 14 days postinjection and analyzed by real-time polymerase chain reaction and GFP immunohistochemistry to assess the presence of AAV genomes and GFP expression, respectively. Spinal cords were positive for AAV genomes at both time points. GFP immunohistochemistry revealed infrequent labeling of LMNs across all time points and injection routes. Somewhat surprisingly, there was extensive labeling of fibers in the dorsal horns and columns, indicating dorsal root ganglion transduction across all time points and injection routes. Our data suggest that systemic injection of rAAV8 is not an effective delivery route to target lower motor neurons, but could be useful for targeting sensory pathways in chronic pain.

  14. Impaired chemosensitivity of mouse dorsal raphe serotonergic neurons overexpressing serotonin 1A (Htr1a receptors.

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    Gilda Baccini

    Full Text Available BACKGROUND: Serotonergic system participates in a wide range of physiological processes and behaviors, but its role is generally considered as modulatory and noncrucial, especially concerning life-sustaining functions. We recently created a transgenic mouse line in which a functional deficit in serotonin homeostasis due to excessive serotonin autoinhibition was produced by inducing serotonin 1A receptor (Htr1a overexpression selectively in serotonergic neurons (Htr1a raphe-overexpressing or Htr1a(RO mice. Htr1a(RO mice exhibit episodes of autonomic dysregulation, cardiovascular crises and death, resembling those of sudden infant death syndrome (SIDS and revealing a life-supporting role of serotonergic system in autonomic control. Since midbrain serotonergic neurons are chemosensitive and are implicated in arousal we hypothesized that their chemosensitivity might be impaired in Htr1a(RO mice. PRINCIPAL FINDINGS: Loose-seal cell-attached recordings in brainstem slices revealed that serotonergic neurons in dorsal raphe nucleus of Htr1a(RO mice have dramatically reduced responses to hypercapnic challenge as compared with control littermates. In control mice, application of 9% CO(2 produced an increase in firing rate of serotonergic neurons (0.260 ± 0.041 Hz, n=20, p=0.0001 and application of 3% CO(2 decreased their firing rate (-0.142 ± 0.025 Hz, n=17, p=0.0008. In contrast, in Htr1a(RO mice, firing rate of serotonergic neurons was not significantly changed by 9% CO(2 (0.021 ± 0.034 Hz, n=16, p=0.49 and by 3% CO(2 (0.012 ± 0.046 Hz, n=12, p=0.97. CONCLUSIONS: Our findings support the hypothesis that chemosensitivity of midbrain serotonergic neurons provides a physiological mechanism for arousal responses to life-threatening episodes of hypercapnia and that functional impairment, such as excessive autoinhibition, of midbrain serotonergic neuron responses to hypercapnia may contribute to sudden death.

  15. Study on the Mechanism Underlying the Regulation of the NMDA Receptor Pathway in Spinal Dorsal Horns of Visceral Hypersensitivity Rats by Moxibustion

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    L. D. Wang

    2016-01-01

    Full Text Available Visceral hypersensitivity is enhanced in irritable bowel syndrome (IBS patients. Treatment of IBS visceral pain by moxibustion methods has a long history and rich clinical experience. In the clinic, moxibustion on the Tianshu (ST25 and Shangjuxu (ST37 acupoints can effectively treat bowel disease with visceral pain and diarrhea symptoms. To investigate the regulatory function of moxibustion on the Tianshu (ST25 and Shangjuxu (ST37 acupoints on spinal cord NR1, NR2B, and PKCε protein and mRNA expression in irritable bowel syndrome (IBS visceral hypersensitivity rats, we did some research. In the study, we found that moxibustion effectively relieved the IBS visceral hyperalgesia status of rats. Analgesic effect of moxibustion was similar to intrathecal injection of Ro 25-6981. The expression of NR1, NR2B, and PKCε in the spinal dorsal horns of IBS visceral hyperalgesia rats increased. Moxibustion on the Tianshu and Shangjuxu acupoints might inhibit the visceral hypersensitivity, simultaneously decreasing the expression of NR1, NR2B, and PKCε in spinal cord of IBS visceral hyperalgesia rats. Based on the above experimental results, we hypothesized NR1, NR2B, and PKCε of spinal cord could play an important role in moxibustion inhibiting the process of central sensitization and visceral hyperalgesia state.

  16. TRPA1 in the spinal dorsal horn is involved in post-inflammatory visceral hypersensitivity: in vivo study using TNBS-treated rat model.

    Science.gov (United States)

    Li, Qian; Guo, Cheng-Hao; Chowdhury, Mohammed Ali; Dai, Tao-Li; Han, Wei

    2016-01-01

    The transient receptor potential ankyrin-1 (TRPA1) channel, a pain transducer and amplifier, is drawing increasing attention in the field of visceral hypersensitivity, commonly seen in irritable bowel syndrome and inflammatory bowel disease. However, the role of TRPA1 in visceral nociception during post-inflammatory states is not well defined. Here, we explore the correlation between TRPA1 expression in the spinal dorsal horn (SDH) and persistent post-inflammatory visceral hypersensitivity. We injected rats intracolonically with 2,4,6-trinitrobenzene sulfonic acid (TNBS) or vehicle (n=12 per group). Post-inflammatory visceral hypersensitivity was assessed by recording the electromyographic activity of the external oblique muscle in response to colorectal distension. TRPA1 expression and distribution in the spinal cord and colon were examined by Western blotting and immunohistochemistry. Animals exposed to TNBS had more abdominal contractions than vehicle-injected controls ( P hypersensitivity in the rat and provides insight into potential therapeutic targets for the control of persistent visceral hypersensitivity.

  17. The effects of capsaicin and acidity on currents generated by noxious heat in cultured neonatal rat dorsal root ganglion neurones

    Czech Academy of Sciences Publication Activity Database

    Vlachová, Viktorie; Lyfenko, Alla; Orkand, R. K.; Vyklický st., Ladislav

    2001-01-01

    Roč. 533, č. 3 (2001), s. 717-728 ISSN 0022-3751 R&D Projects: GA ČR GA305/00/1639; GA MŠk LN00B122 Institutional research plan: CEZ:AV0Z5011922 Keywords : capsaicin * dorsal root ganglion neurones * neonatal rat Subject RIV: FH - Neurology Impact factor: 4.476, year: 2001

  18. A compact dual promoter adeno-associated viral vector for efficient delivery of two genes to dorsal root ganglion neurons

    NARCIS (Netherlands)

    Fagoe, N D; Eggers, R; Verhaagen, J; Mason, M R J

    Adeno-associated viral (AAV) vectors based on serotype 5 are an efficient means to target dorsal root ganglia (DRG) to study gene function in the primary sensory neurons of the peripheral nervous system. In this study, we have developed a compact AAV dual promoter vector composed of the

  19. Dorsal-CA1 Hippocampal Neuronal Ensembles Encode Nicotine-Reward Contextual Associations.

    Science.gov (United States)

    Xia, Li; Nygard, Stephanie K; Sobczak, Gabe G; Hourguettes, Nicholas J; Bruchas, Michael R

    2017-06-06

    Natural and drug rewards increase the motivational valence of stimuli in the environment that, through Pavlovian learning mechanisms, become conditioned stimuli that directly motivate behavior in the absence of the original unconditioned stimulus. While the hippocampus has received extensive attention for its role in learning and memory processes, less is known regarding its role in drug-reward associations. We used in vivo Ca 2+ imaging in freely moving mice during the formation of nicotine preference behavior to examine the role of the dorsal-CA1 region of the hippocampus in encoding contextual reward-seeking behavior. We show the development of specific neuronal ensembles whose activity encodes nicotine-reward contextual memories and that are necessary for the expression of place preference. Our findings increase our understanding of CA1 hippocampal function in general and as it relates to reward processing by identifying a critical role for CA1 neuronal ensembles in nicotine place preference. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Citral sensing by Transient [corrected] receptor potential channels in dorsal root ganglion neurons.

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    Stephanie C Stotz

    2008-05-01

    Full Text Available Transient receptor potential (TRP ion channels mediate key aspects of taste, smell, pain, temperature sensation, and pheromone detection. To deepen our understanding of TRP channel physiology, we require more diverse pharmacological tools. Citral, a bioactive component of lemongrass, is commonly used as a taste enhancer, as an odorant in perfumes, and as an insect repellent. Here we report that citral activates TRP channels found in sensory neurons (TRPV1 and TRPV3, TRPM8, and TRPA1, and produces long-lasting inhibition of TRPV1-3 and TRPM8, while transiently blocking TRPV4 and TRPA1. Sustained citral inhibition is independent of internal calcium concentration, but is state-dependent, developing only after TRP channel opening. Citral's actions as a partial agonist are not due to cysteine modification of the channels nor are they a consequence of citral's stereoisoforms. The isolated aldehyde and alcohol cis and trans enantiomers (neral, nerol, geranial, and geraniol each reproduce citral's actions. In juvenile rat dorsal root ganglion neurons, prolonged citral inhibition of native TRPV1 channels enabled the separation of TRPV2 and TRPV3 currents. We find that TRPV2 and TRPV3 channels are present in a high proportion of these neurons (94% respond to 2-aminoethyldiphenyl borate, consistent with our immunolabeling experiments and previous in situ hybridization studies. The TRPV1 activation requires residues in transmembrane segments two through four of the voltage-sensor domain, a region previously implicated in capsaicin activation of TRPV1 and analogous menthol activation of TRPM8. Citral's broad spectrum and prolonged sensory inhibition may prove more useful than capsaicin for allodynia, itch, or other types of pain involving superficial sensory nerves and skin.

  1. Transglial transmission at the dorsal root ganglion sandwich synapse: glial cell to postsynaptic neuron communication.

    Science.gov (United States)

    Rozanski, Gabriela M; Li, Qi; Stanley, Elise F

    2013-04-01

    The dorsal root ganglion (DRG) contains a subset of closely-apposed neuronal somata (NS) separated solely by a thin satellite glial cell (SGC) membrane septum to form an NS-glial cell-NS trimer. We recently reported that stimulation of one NS with an impulse train triggers a delayed, noisy and long-lasting response in its NS pair via a transglial signaling pathway that we term a 'sandwich synapse' (SS). Transmission could be unidirectional or bidirectional and facilitated in response to a second stimulus train. We have shown that in chick or rat SS the NS-to-SGC leg of the two-synapse pathway is purinergic via P2Y2 receptors but the second SGC-to-NS synapse mechanism remained unknown. A noisy evoked current in the target neuron, a reversal potential close to 0 mV, and insensitivity to calcium scavengers or G protein block favored an ionotropic postsynaptic receptor. Selective block by D-2-amino-5-phosphonopentanoate (AP5) implicated glutamatergic transmission via N-methyl-d-aspartate receptors. This agent also blocked NS responses evoked by puff of UTP, a P2Y2 agonist, directly onto the SGC cell, confirming its action at the second synapse of the SS transmission pathway. The N-methyl-d-aspartate receptor NR2B subunit was implicated by block of transmission with ifenprodil and by its immunocytochemical localization to the NS membrane, abutting the glial septum P2Y2 receptor. Isolated DRG cell clusters exhibited daisy-chain and branching NS-glial cell-NS contacts, suggestive of a network organization within the ganglion. The identification of the glial-to-neuron transmitter and receptor combination provides further support for transglial transmission and completes the DRG SS molecular transmission pathway. © 2013 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  2. Purinergic transmission and transglial signaling between neuron somata in the dorsal root ganglion.

    Science.gov (United States)

    Rozanski, Gabriela M; Li, Qi; Kim, Hyunhee; Stanley, Elise F

    2013-02-01

    Most dorsal root ganglion neuronal somata (NS) are isolated from their neighbours by a satellite glial cell (SGC) sheath. However, some NS are associated in pairs, separated solely by the membrane septum of a common SGC to form a neuron-glial cell-neuron (NGlN) trimer. We reported that stimulation of one NS evokes a delayed, noisy and long-duration inward current in both itself and its passive partner that was blocked by suramin, a general purinergic antagonist. Here we test the hypothesis that NGlN transmission involves purinergic activation of the SGC. Stimulation of the NS triggered a sustained current noise in the SGC. Block of transmission through the NGlN by reactive blue 2 or thapsigargin, a Ca(2+) store-depletion agent, implicated a Ca(2+) store discharge-linked P2Y receptor. P2Y2 was identified by simulation of the NGlN-like transmission by puffing UTP onto the SGC and by immunocytochemical localization to the SGC membrane septum. Block of the UTP effect by BAPTA, an intracellular Ca(2+) scavenger, supported the involvement of SGC Ca(2+) stores in the signaling pathway. We infer that transmission through the NGlN trimer involves secretion of ATP from the NS and triggering of SGC Ca(2+) store discharge via P2Y2 receptors. Presumably, cytoplasmic Ca(2+) elevation leads to the release of an as-yet unidentified second transmitter from the glial cell to complete transmission. Thus, the two NS of the NGlN trimer communicate via a 'sandwich synapse' transglial pathway, a novel signaling mechanism that may contribute to information transfer in other regions of the nervous system. © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  3. Pronociceptive and Antinociceptive Effects of Buprenorphine in the Spinal Cord Dorsal Horn Cover a Dose Range of Four Orders of Magnitude

    Science.gov (United States)

    Gerhold, Katharina J.; Drdla-Schutting, Ruth; Honsek, Silke D.; Forsthuber, Liesbeth

    2015-01-01

    Due to its distinct pharmacological profile and lower incidence of adverse events compared with other opioids, buprenorphine is considered a safe option for pain and substitution therapy. However, despite its wide clinical use, little is known about the synaptic effects of buprenorphine in nociceptive pathways. Here, we demonstrate dose-dependent, bimodal effects of buprenorphine on transmission at C-fiber synapses in rat spinal cord dorsal horn in vivo. At an analgesically active dose of 1500 μg·kg−1, buprenorphine reduced the strength of spinal C-fiber synapses. This depression required activation of spinal opioid receptors, putatively μ1-opioid receptors, as indicated by its sensitivity to spinal naloxone and to the selective μ1-opioid receptor antagonist naloxonazine. In contrast, a 15,000-fold lower dose of buprenorphine (0.1 μg·kg−1), which caused thermal and mechanical hyperalgesia in behaving animals, induced an enhancement of transmission at spinal C-fiber synapses. The ultra-low-dose buprenorphine-induced synaptic facilitation was mediated by supraspinal naloxonazine-insensitive, but CTOP-sensitive μ-opioid receptors, descending serotonergic pathways, and activation of spinal glial cells. Selective inhibition of spinal 5-hydroxytryptamine-2 receptors (5-HT2Rs), putatively located on spinal astrocytes, abolished both the induction of synaptic facilitation and the hyperalgesia elicited by ultra-low-dose buprenorphine. Our study revealed that buprenorphine mediates its modulatory effects on transmission at spinal C-fiber synapses by dose dependently acting on distinct μ-opioid receptor subtypes located at different levels of the neuraxis. PMID:26134641

  4. Neurokinin-1 (NK-1 receptor and brain-derived neurotrophic factor (BDNF gene expression is differentially modulated in the rat spinal dorsal horn and hippocampus during inflammatory pain

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    McCarson Kenneth E

    2007-10-01

    Full Text Available Abstract Persistent pain produces complex alterations in sensory pathways of the central nervous system (CNS through activation of various nociceptive mechanisms. However, the effects of pain on higher brain centers, particularly the influence of the stressful component of pain on the limbic system, are poorly understood. Neurokinin-1 (NK-1 receptors and brain-derived neurotrophic factor (BDNF, known neuromediators of hyperalgesia and spinal central sensitization, have also been implicated in the plasticity and neurodegeneration occurring in the hippocampal formation during exposures to various stressors. Results of this study showed that injections of complete Freund's adjuvant (CFA into the hind paw increased NK-1 receptor and BDNF mRNA levels in the ipsilateral dorsal horn, supporting an important role for these nociceptive mediators in the amplification of ascending pain signaling. An opposite effect was observed in the hippocampus, where CFA down-regulated NK-1 receptor and BDNF gene expression, phenomena previously observed in immobilization models of stress and depression. Western blot analyses demonstrated that in the spinal cord, CFA also increased levels of phosphorylated cAMP response element-binding protein (CREB, while in the hippocampus the activation of this transcription factor was significantly reduced, further suggesting that tissue specific transcription of either NK-1 or BDNF genes may be partially regulated by common intracellular transduction mechanisms mediated through activation of CREB. These findings suggest that persistent nociception induces differential regional regulation of NK-1 receptor and BDNF gene expression and CREB activation in the CNS, potentially reflecting varied roles of these neuromodulators in the spinal cord during persistent sensory activation vs. modulation of the higher brain structures such as the hippocampus.

  5. Spike propagation through the dorsal root ganglia in an unmyelinated sensory neuron: a modeling study.

    Science.gov (United States)

    Sundt, Danielle; Gamper, Nikita; Jaffe, David B

    2015-12-01

    Unmyelinated C-fibers are a major type of sensory neurons conveying pain information. Action potential conduction is regulated by the bifurcation (T-junction) of sensory neuron axons within the dorsal root ganglia (DRG). Understanding how C-fiber signaling is influenced by the morphology of the T-junction and the local expression of ion channels is important for understanding pain signaling. In this study we used biophysical computer modeling to investigate the influence of axon morphology within the DRG and various membrane conductances on the reliability of spike propagation. As expected, calculated input impedance and the amplitude of propagating action potentials were both lowest at the T-junction. Propagation reliability for single spikes was highly sensitive to the diameter of the stem axon and the density of voltage-gated Na(+) channels. A model containing only fast voltage-gated Na(+) and delayed-rectifier K(+) channels conducted trains of spikes up to frequencies of 110 Hz. The addition of slowly activating KCNQ channels (i.e., KV7 or M-channels) to the model reduced the following frequency to 30 Hz. Hyperpolarization produced by addition of a much slower conductance, such as a Ca(2+)-dependent K(+) current, was needed to reduce the following frequency to 6 Hz. Attenuation of driving force due to ion accumulation or hyperpolarization produced by a Na(+)-K(+) pump had no effect on following frequency but could influence the reliability of spike propagation mutually with the voltage shift generated by a Ca(2+)-dependent K(+) current. These simulations suggest how specific ion channels within the DRG may contribute toward therapeutic treatments for chronic pain. Copyright © 2015 the American Physiological Society.

  6. A SAGE-based screen for genes expressed in sub-populations of neurons in the mouse dorsal root ganglion

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    Garces Alain

    2007-11-01

    Full Text Available Abstract Background The different sensory modalities temperature, pain, touch and muscle proprioception are carried by somatosensory neurons of the dorsal root ganglia. Study of this system is hampered by the lack of molecular markers for many of these neuronal sub-types. In order to detect genes expressed in sub-populations of somatosensory neurons, gene profiling was carried out on wild-type and TrkA mutant neonatal dorsal root ganglia (DRG using SAGE (serial analysis of gene expression methodology. Thermo-nociceptors constitute up to 80 % of the neurons in the DRG. In TrkA mutant DRGs, the nociceptor sub-class of sensory neurons is lost due to absence of nerve growth factor survival signaling through its receptor TrkA. Thus, comparison of wild-type and TrkA mutants allows the identification of transcripts preferentially expressed in the nociceptor or mechano-proprioceptor subclasses, respectively. Results Our comparison revealed 240 genes differentially expressed between the two tissues (P Conclusion We have identified and characterized the detailed expression patterns of three genes in the developing DRG, placing them in the context of the known major neuronal sub-types defined by molecular markers. Further analysis of differentially expressed genes in this tissue promises to extend our knowledge of the molecular diversity of different cell types and forms the basis for understanding their particular functional specificities.

  7. Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus.

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    Cesar Celis Ceballos

    2016-10-01

    Full Text Available In a neuronal population, several combinations of its ionic conductances are used to attain a specific firing phenotype. Some neurons present heterogeneity in their firing, generally produced by expression of a specific conductance, but how additional conductances vary along in order to homeostatically regulate membrane excitability is less known. Dorsal cochlear nucleus principal neurons, fusiform neurons, display heterogeneous spontaneous action potential activity and thus represent an appropriate model to study the role of different conductances in establishing firing heterogeneity. Particularly, fusiform neurons are divided into quiet, with no spontaneous firing, or active neurons, presenting spontaneous, regular firing. These modes are determined by the expression levels of an intrinsic membrane conductance, an inwardly rectifying potassium current (IKir. In this work, we tested whether other subthreshold conductances vary homeostatically to maintain membrane excitability constant across the two subtypes. We found that Ih expression covaries specifically with IKir in order to maintain membrane resistance constant. The impact of Ih on membrane resistance is dependent on the level of IKir expression, being much smaller in quiet neurons with bigger IKir, but Ih variations are not relevant for creating the quiet and active phenotypes. Finally, we demonstrate that the individual proportion of each conductance, and not their absolute conductance, is relevant for determining the neuronal firing mode. We conclude that in fusiform neurons the variations of their different subthreshold conductances are limited to specific conductances in order to create firing heterogeneity and maintain membrane homeostasis.

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

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    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

  9. Mushroom spine dynamics in medium spiny neurons of dorsal striatum associated with memory of moderate and intense training.

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    Bello-Medina, Paola C; Flores, Gonzalo; Quirarte, Gina L; McGaugh, James L; Prado Alcalá, Roberto A

    2016-10-18

    A growing body of evidence indicates that treatments that typically impair memory consolidation become ineffective when animals are given intense training. This effect has been obtained by treatments interfering with the neural activity of several brain structures, including the dorsal striatum. The mechanisms that mediate this phenomenon are unknown. One possibility is that intense training promotes the transfer of information derived from the enhanced training to a wider neuronal network. We now report that inhibitory avoidance (IA) induces mushroom spinogenesis in the medium spiny neurons (MSNs) of the dorsal striatum in rats, which is dependent upon the intensity of the foot-shock used for training; that is, the effect is seen only when high-intensity foot-shock is used in training. We also found that the relative density of thin spines was reduced. These changes were evident at 6 h after training and persisted for at least 24 h afterward. Importantly, foot-shock alone did not increase spinogenesis. Spine density in MSNs in the accumbens was also increased, but the increase did not correlate with the associative process involved in IA; rather, it resulted from the administration of the aversive stimulation alone. These findings suggest that mushroom spines of MSNs of the dorsal striatum receive afferent information that is involved in the integrative activity necessary for memory consolidation, and that intense training facilitates transfer of information from the dorsal striatum to other brain regions through augmented spinogenesis.

  10. The cholinergic agonist carbachol increases the frequency of spontaneous GABAergic synaptic currents in dorsal raphe serotonergic neurons in the mouse.

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    Yang, C; Brown, R E

    2014-01-31

    Dorsal raphe nucleus (DRN) serotonin (5-HT) neurons play an important role in feeding, mood control and stress responses. One important feature of their activity across the sleep-wake cycle is their reduced firing during rapid-eye-movement (REM) sleep which stands in stark contrast to the wake/REM-on discharge pattern of brainstem cholinergic neurons. A prominent model of REM sleep control posits a reciprocal interaction between these cell groups. 5-HT inhibits cholinergic neurons, and activation of nicotinic receptors can excite DRN 5-HT neurons but the cholinergic effect on inhibitory inputs is incompletely understood. Here, in vitro, in DRN brain slices prepared from GAD67-GFP knock-in mice, a brief (3 min) bath application of carbachol (50 μM) increased the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) in GFP-negative, putative 5-HT neurons but did not affect miniature (tetrodotoxin-insensitive) IPSCs. Carbachol had no direct postsynaptic effect. Thus, carbachol likely increases the activity of local GABAergic neurons which synapse on 5-HT neurons. Removal of dorsal regions of the slice including the ventrolateral periaqueductal gray (vlPAG) region where GABAergic neurons projecting to the DRN have been identified, abolished the effect of carbachol on sIPSCs whereas the removal of ventral regions containing the oral region of the pontine reticular nucleus (PnO) did not. In addition, carbachol directly excited GFP-positive, GABAergic vlPAG neurons. Antagonism of both muscarinic and nicotinic receptors completely abolished the effects of carbachol. We suggest cholinergic neurons inhibit DRN 5-HT neurons when acetylcholine levels are lower i.e. during quiet wakefulness and the beginning of REM sleep periods, in part via excitation of muscarinic and nicotinic receptors located on local vlPAG and DRN GABAergic neurons. Higher firing rates or burst firing of cholinergic neurons associated with attentive wakefulness or phasic REM sleep periods

  11. The effects of canine bone marrow stromal cells on neuritogenesis from dorsal root ganglion neurons in vitro.

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    Kamishina, Hiroaki; Cheeseman, Jennifer A; Clemmons, Roger M

    2009-10-01

    The present in vitro study was designed to evaluate whether canine bone marrow stromal cells (BMSCs) promote neurite outgrowth from dorsal root ganglion (DRG) neurons. Bone marrow aspirates were collected from iliac crests of three young adult dogs. DRG neurons were cultured on BMSCs, fibroblasts, or laminin substrates. DRG neurons were also cultured in BMSC- or fibroblast-conditioned media. DRG neurons grown on BMSCs extended longer neurites and developed a much more elaborate conformation of branching neurites compared to those on fibroblasts or laminin. Quantitative analysis revealed that these effects were associated with the emergence of increased numbers of primary and branching neurites. The effect appears to be dependent upon cell-cell interactions rather than by elaboration of diffusible molecules. With more extensive investigations into the basic biology of canine BMSCs, their ability for promoting neurite outgrowth may be translated into a novel therapeutic strategy for dogs with a variety of neurological disorders.

  12. Growth of rat dorsal root ganglion neurons on a novel self-assembling scaffold containing IKVAV sequence

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    Zou Zhenwei; Zheng Qixin [Department of Orthopaedics, Union Hospital, Tongji Medical college of Huazhong University of science and technology, Wuhan, 430022 (China); Wu Yongchao, E-mail: wuyongchao@hotmail.com [Department of Orthopaedics, Union Hospital, Tongji Medical college of Huazhong University of science and technology, Wuhan, 430022 (China); Song Yulin; Wu Bin [Department of Orthopaedics, Union Hospital, Tongji Medical college of Huazhong University of science and technology, Wuhan, 430022 (China)

    2009-08-31

    The potential benefits of self-assembly in synthesizing materials for the treatment of both peripheral and central nervous system disorders are tremendous. In this study, we synthesized peptide-amphiphile (PA) molecules containing IKVAV sequence and induced self-assembly of the PA solutions in vitro to form nanofiber gels. Then, we tested the characterization of gels by transmission electron microscopy and demonstrated the biocompatibility of this gel towards rat dorsal root ganglion neurons. The nanofiber gel was formed by self-assembly of IKVAV PA molecules, which was triggered by metal ions. The fibers were 7-8 nm in diameter and with lengths of hundreds of nanometers. Gels were shown to be non-toxic to neurons and able to promote neurons adhesion and neurite sprouting. The results indicated that the self-assembling scaffold containing IKVAV sequence had excellent biocompatibility with adult sensory neurons and could be useful in nerve tissue engineering.

  13. Growth of rat dorsal root ganglion neurons on a novel self-assembling scaffold containing IKVAV sequence

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    Zou Zhenwei; Zheng Qixin; Wu Yongchao; Song Yulin; Wu Bin

    2009-01-01

    The potential benefits of self-assembly in synthesizing materials for the treatment of both peripheral and central nervous system disorders are tremendous. In this study, we synthesized peptide-amphiphile (PA) molecules containing IKVAV sequence and induced self-assembly of the PA solutions in vitro to form nanofiber gels. Then, we tested the characterization of gels by transmission electron microscopy and demonstrated the biocompatibility of this gel towards rat dorsal root ganglion neurons. The nanofiber gel was formed by self-assembly of IKVAV PA molecules, which was triggered by metal ions. The fibers were 7-8 nm in diameter and with lengths of hundreds of nanometers. Gels were shown to be non-toxic to neurons and able to promote neurons adhesion and neurite sprouting. The results indicated that the self-assembling scaffold containing IKVAV sequence had excellent biocompatibility with adult sensory neurons and could be useful in nerve tissue engineering.

  14. Quantitative Analysis of Rat Dorsal Root Ganglion Neurons Cultured on Microelectrode Arrays Based on Fluorescence Microscopy Image Processing.

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    Mari, João Fernando; Saito, José Hiroki; Neves, Amanda Ferreira; Lotufo, Celina Monteiro da Cruz; Destro-Filho, João-Batista; Nicoletti, Maria do Carmo

    2015-12-01

    Microelectrode Arrays (MEA) are devices for long term electrophysiological recording of extracellular spontaneous or evocated activities on in vitro neuron culture. This work proposes and develops a framework for quantitative and morphological analysis of neuron cultures on MEAs, by processing their corresponding images, acquired by fluorescence microscopy. The neurons are segmented from the fluorescence channel images using a combination of segmentation by thresholding, watershed transform, and object classification. The positioning of microelectrodes is obtained from the transmitted light channel images using the circular Hough transform. The proposed method was applied to images of dissociated culture of rat dorsal root ganglion (DRG) neuronal cells. The morphological and topological quantitative analysis carried out produced information regarding the state of culture, such as population count, neuron-to-neuron and neuron-to-microelectrode distances, soma morphologies, neuron sizes, neuron and microelectrode spatial distributions. Most of the analysis of microscopy images taken from neuronal cultures on MEA only consider simple qualitative analysis. Also, the proposed framework aims to standardize the image processing and to compute quantitative useful measures for integrated image-signal studies and further computational simulations. As results show, the implemented microelectrode identification method is robust and so are the implemented neuron segmentation and classification one (with a correct segmentation rate up to 84%). The quantitative information retrieved by the method is highly relevant to assist the integrated signal-image study of recorded electrophysiological signals as well as the physical aspects of the neuron culture on MEA. Although the experiments deal with DRG cell images, cortical and hippocampal cell images could also be processed with small adjustments in the image processing parameter estimation.

  15. Sporadic lower motor neuron disease with a snake eyes appearance on the cervical anterior horns by MRI.

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    Sasaki, Shoichi

    2015-09-01

    Lower motor neuron disease (LMND) is the term generally used to describe diseases in which only lower motor neuron signs are detected. A snake eyes appearance on magnetic resonance imaging (MRI) is associated with a wide spectrum of neurological conditions including LMND. The author reports on three unique LMND patients with upper limb muscle weakness and atrophy who show a snake eyes appearance by MRI. The patients were aged 18, 40 and 52 years, respectively, at the onset of the disease and had a longstanding clinical course (more than 10 years for two patients and 8 years for one patient). They were followed up for more than 6 years. Clinical manifestations were characterized by (1) longstanding slow progression or delayed spontaneous arrest of asymmetric lower motor neuron signs localized exclusively in the upper extremities with unilateral predominance and distal or proximal preponderance; (2) the absence of upper motor neuron signs, bulbar signs, sensory disturbances and respiratory involvement; (3) a snake eyes appearance on the anterior horns of the cervical cord over more than 3 vertebrae by axial T2-weighted MRI and a longitudinal linear-shaped T2-signal hyperintensity by sagittal MRI; (4) neurogenic change with fasciculation and denervation potentials (fibrillation and a positive sharp wave) confined to the affected muscles by needle electromyogram; and (5) normal cerebrospinal fluid and a normal creatine kinase level. These cases did not fall into any existing category of LMND, such as progressive muscular atrophy, flail arm syndrome or Hirayama disease. These patients should be classified as sporadic LMND with snake eyes on MRI with a relatively benign prognosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Painful Cervical Facet Joint Injury Is Accompanied by Changes in the Number of Excitatory and Inhibitory Synapses in the Superficial Dorsal Horn That Differentially Relate to Local Tissue Injury Severity.

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    Ita, Meagan E; Crosby, Nathan D; Bulka, Ben A; Winkelstein, Beth A

    2017-06-15

    Immunohistochemistry labeled pre- and postsynaptic structural markers to quantify excitatory and inhibitory synapses in the spinal superficial dorsal horn at 14 days after painful facet joint injury in the rat. The objective of this study was to investigate the relationship between pain and synapse density in the spinal cord after facet injury. Neck pain is a major contributor to disability and often becomes chronic. The cervical facet joints are susceptible to loading-induced painful injury, initiating spinal central sensitization responses. Although excitatory synapse plasticity has been reported in the superficial dorsal horn early after painful facet injury, whether excitatory and/or inhibitory synapse density is altered at a time when pain is maintained is unknown. Rats underwent either a painful C6/C7 facet joint distraction or sham surgery. Mechanical hyperalgesia was measured and immunohistochemistry techniques for synapse quantification were used to quantify excitatory and inhibitory synapse densities in the superficial dorsal horn at day 14. Logarithmic correlation analyses evaluated whether the severity of facet injury correlated with either behavioral or synaptic outcomes. Facet joint injury induces pain that is sustained until day 14 (P Injury severity is significantly correlated with pain at days 1 (P = 0.0011) and 14 (P = 0.0002), but only with inhibitory, not excitatory, synapse density (P = 0.0025) at day 14. This study demonstrates a role for structural plasticity in both excitatory and inhibitory synapses in the maintenance of facet-mediated joint pain, and that altered inhibitory, but not excitatory, synapse density correlates to the severity of painful joint injury. Understanding the functional consequences of this spinal structural plasticity is critical to elucidate mechanisms of chronic joint pain. N /A.

  17. Computational modeling of spike generation in serotonergic neurons of the dorsal raphe nucleus.

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    Tuckwell, Henry C; Penington, Nicholas J

    2014-07-01

    Serotonergic neurons of the dorsal raphe nucleus, with their extensive innervation of limbic and higher brain regions and interactions with the endocrine system have important modulatory or regulatory effects on many cognitive, emotional and physiological processes. They have been strongly implicated in responses to stress and in the occurrence of major depressive disorder and other psychiatric disorders. In order to quantify some of these effects, detailed mathematical models of the activity of such cells are required which describe their complex neurochemistry and neurophysiology. We consider here a single-compartment model of these neurons which is capable of describing many of the known features of spike generation, particularly the slow rhythmic pacemaking activity often observed in these cells in a variety of species. Included in the model are 11 kinds of ion channels: a fast sodium current INa, a delayed rectifier potassium current IKDR, a transient potassium current IA, a slow non-inactivating potassium current IM, a low-threshold calcium current IT, two high threshold calcium currents IL and IN, small and large conductance potassium currents ISK and IBK, a hyperpolarization-activated cation current IH and a leak current ILeak. In Sections 3-8, each current type is considered in detail and parameters estimated from voltage clamp data where possible. Three kinds of model are considered for the BK current and two for the leak current. Intracellular calcium ion concentration Cai is an additional component and calcium dynamics along with buffering and pumping is discussed in Section 9. The remainder of the article contains descriptions of computed solutions which reveal both spontaneous and driven spiking with several parameter sets. Attention is focused on the properties usually associated with these neurons, particularly long duration of action potential, steep upslope on the leading edge of spikes, pacemaker-like spiking, long-lasting afterhyperpolarization

  18. Morphology, classification, and distribution of the projection neurons in the dorsal lateral geniculate nucleus of the rat.

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    Ling, Changying; Hendrickson, Michael L; Kalil, Ronald E

    2012-01-01

    The morphology of confirmed projection neurons in the dorsal lateral geniculate nucleus (dLGN) of the rat was examined by filling these cells retrogradely with biotinylated dextran amine (BDA) injected into the visual cortex. BDA-labeled projection neurons varied widely in the shape and size of their cell somas, with mean cross-sectional areas ranging from 60-340 µm(2). Labeled projection neurons supported 7-55 dendrites that spanned up to 300 µm in length and formed dendritic arbors with cross-sectional areas of up to 7.0 × 10(4) µm(2). Primary dendrites emerged from cell somas in three broad patterns. In some dLGN projection neurons, primary dendrites arise from the cell soma at two poles spaced approximately 180° apart. In other projection neurons, dendrites emerge principally from one side of the cell soma, while in a third group of projection neurons primary dendrites emerge from the entire perimeter of the cell soma. Based on these three distinct patterns in the distribution of primary dendrites from cell somas, we have grouped dLGN projection neurons into three classes: bipolar cells, basket cells and radial cells, respectively. The appendages seen on dendrites also can be grouped into three classes according to differences in their structure. Short "tufted" appendages arise mainly from the distal branches of dendrites; "spine-like" appendages, fine stalks with ovoid heads, typically are seen along the middle segments of dendrites; and "grape-like" appendages, short stalks that terminate in a cluster of ovoid bulbs, appear most often along the proximal segments of secondary dendrites of neurons with medium or large cell somas. While morphologically diverse dLGN projection neurons are intermingled uniformly throughout the nucleus, the caudal pole of the dLGN contains more small projection neurons of all classes than the rostral pole.

  19. Morphology, classification, and distribution of the projection neurons in the dorsal lateral geniculate nucleus of the rat.

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    Changying Ling

    Full Text Available The morphology of confirmed projection neurons in the dorsal lateral geniculate nucleus (dLGN of the rat was examined by filling these cells retrogradely with biotinylated dextran amine (BDA injected into the visual cortex. BDA-labeled projection neurons varied widely in the shape and size of their cell somas, with mean cross-sectional areas ranging from 60-340 µm(2. Labeled projection neurons supported 7-55 dendrites that spanned up to 300 µm in length and formed dendritic arbors with cross-sectional areas of up to 7.0 × 10(4 µm(2. Primary dendrites emerged from cell somas in three broad patterns. In some dLGN projection neurons, primary dendrites arise from the cell soma at two poles spaced approximately 180° apart. In other projection neurons, dendrites emerge principally from one side of the cell soma, while in a third group of projection neurons primary dendrites emerge from the entire perimeter of the cell soma. Based on these three distinct patterns in the distribution of primary dendrites from cell somas, we have grouped dLGN projection neurons into three classes: bipolar cells, basket cells and radial cells, respectively. The appendages seen on dendrites also can be grouped into three classes according to differences in their structure. Short "tufted" appendages arise mainly from the distal branches of dendrites; "spine-like" appendages, fine stalks with ovoid heads, typically are seen along the middle segments of dendrites; and "grape-like" appendages, short stalks that terminate in a cluster of ovoid bulbs, appear most often along the proximal segments of secondary dendrites of neurons with medium or large cell somas. While morphologically diverse dLGN projection neurons are intermingled uniformly throughout the nucleus, the caudal pole of the dLGN contains more small projection neurons of all classes than the rostral pole.

  20. Difference of acute dissociation and 1-day culture on the electrophysiological properties of rat dorsal root ganglion neurons.

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    Song, Yuanlong; Zhang, Miaomiao; Tao, Xiaoqing; Xu, Zifen; Zheng, Yunjie; Zhu, Minjie; Zhang, Liangpin; Qiao, Jinhan; Gao, Linlin

    2018-01-19

    The dissociated dorsal root ganglion (DRG) neurons with or without culture were widely used for investigation of their electrophysiological properties. The culture procedures, however, may alter the properties of these neurons and the effects are not clear. In the present study, we recorded the action potentials (AP) and the voltage-gated Na + , K + , and Ca 2+ currents with patch clamp technique and measured the mRNA of Nav1.6-1.9 and Cav2.1-2.2 with real-time PCR technique from acutely dissociated and 1-day (1-d) cultured DRG neurons. The effects of the nerve growth factor (NGF) on the expression of Nav1.6-1.9 and Cav2.1-2.2 were evaluated. The neurons were classified as small (DRG-S), medium (DRG-M), and large (DRG-L), according to their size frequency distribution pattern. We found 1-d culture increased the AP size but reduced the excitability, and reduced the voltage-gated Na + and Ca 2+ currents and their corresponding mRNA expression in all types of neurons. The lack of NGF in the culture medium may contribute to the reduced Na + and Ca 2+ current, as the application of NGF recovered some of the reduced transcripts (Nav1.9, Cav2.1, and Cav2.2). 1-d culture showed neuron-type specific effects on some of the AP properties: it increased the maximum AP depolarizing rate (MDR) and hyperpolarized the resting membrane potential (RP) in DRG-M and DRG-L neurons, but slowed the maximum AP repolarizing rate (MRR) in DRG-S neurons. In conclusion, the 1-d cultured neurons had different properties with those of the acutely dissociated neurons, and lack of NGF may contribute to some of these differences.

  1. Modulating nitric oxide levels in dorsal root ganglion neurons of rat with low-level laser therapy

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    Zheng, Li-qin; Wang, Yu-hua; He, Yi-peng; Zhou, Jie; Yang, Hong-qin; Zhang, Yan-ding; Xie, Shu-sen

    2015-05-01

    Nitric oxide (NO) and nitric oxide synthase (NOS) have an important role in pain signaling transmission in animal models. Low-level laser therapy (LLLT) is known to have an analgesic effect, but the mechanism is unclear. The aim of the study is to investigate the influence of LLLT on NO release and NOS synthesis in dorsal root ganglion (DRG) neurons, in order to find whether LLLI can ameliorate pain through modulating NO production at the cellular level. The results show that in stress conditions, the laser irradiation at 658 nm can modulate NO production in DRG neurons with soma diameter of about 20 μm in a short time after illumination, and affect NOS synthesis in a dose-dependent manner. It is demonstrated that LLLT might treat pain by altering NO release directly and indirectly in DRG neurons.

  2. Expression profile of vesicular nucleotide transporter (VNUT, SLC17A9) in subpopulations of rat dorsal root ganglion neurons.

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    Nishida, Kentaro; Nomura, Yuka; Kawamori, Kanako; Moriyama, Yoshinori; Nagasawa, Kazuki

    2014-09-05

    ATP plays an important role in the signal transduction between sensory neurons and satellite cells in dorsal root ganglia (DRGs). In primary cultured DRG neurons, ATP is known to be stored in lysosomes via a vesicular nucleotide transporter (VNUT), and to be released into the intercellular space through exocytosis. DRGs consist of large-, medium- and small-sized neurons, which play different roles in sensory transmission, but there is no information on the expression profiles of VNUT in DRG subpopulations. Here, we obtained detailed expression profiles of VNUT in isolated rat DRG tissues. On immunohistochemical analysis, VNUT was found in DRG neurons, and was predominantly expressed by the small- and medium-sized DRG ones, as judged upon visual inspection, and this was compatible with the finding that the number of VNUT-positive DRG neurons in IB4-positive cells was greater than that in NF200-positive ones. These results suggest that VNUT play a role in ATP accumulation in DRG neurons, especially in small- and medium-sized ones, and might be involved in ATP-mediated nociceptive signaling in DRGs. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Cytomorphometric changes in the dorsal raphe neurons after rapid eye movement sleep deprivation are mediated by noradrenalin in rats

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    Biswas Sudipta

    2010-10-01

    Full Text Available Abstract Objectives This study was carried out to investigate the effect of rapid eye movement sleep (REMS deprivation (REMSD on the cytomorphology of the dorsal raphe (DR neurons and to evaluate the possible role of REMSD-induced increased noradrenalin (NA in mediating such effects. Methods Rats were REMS deprived by the flowerpot method; free moving normal home cage rats, large platform and post REMS-deprived recovered rats were used as controls. Further, to evaluate if the effects were induced by NA, separate sets of experimental rats were treated (i.p. with α1-adrenoceptor antagonist, prazosin (PRZ. Histomorphometric analysis of DR neurons in stained brain sections were performed in experimental and control rats; neurons in inferior colliculus (IC served as anatomical control. Results The mean size of DR neurons was larger in REMSD group compared to controls, whereas, neurons in the recovered group of rats did not significantly differ than those in the control animals. Further, mean cell size in the post-REMSD PRZ-treated animals was comparable to those in the control groups. IC neurons were not affected by REMSD. Conclusions REMS loss has been reported to impair several physiological, behavioral and cellular processes. The mean size of the DR neurons was larger in the REMS deprived group of rats than those in the control groups; however, in the REMS deprived and prazosin treated rats the size was comparable to the normal rats. These results showed that REMSD induced increase in DR neuronal size was mediated by NA acting on α1-adrenoceptor. The findings suggest that the sizes of DR neurons are sensitive to REMSD, which if not compensated could lead to neurodegeneration and associated disorders including memory loss and Alzheimer's disease.

  4. Primary sensory neurons regulate Toll-like receptor-4-dependent activity of glial cells in dorsal root ganglia.

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    Tse, K-H; Chow, K B S; Leung, W K; Wong, Y H; Wise, H

    2014-10-24

    Toll-like receptor-4 (TLR4) has been identified in primary sensory neurons, both in vivo and in vitro, but is reportedly absent from satellite glial cells (SGCs). Herein we reveal that, in rat dorsal root ganglia (DRG), SGCs do express TLR4 but this expression is inhibited by direct contact with neurons. Thus, TLR4 mRNA and protein is strongly up-regulated in isolated DRG glial cells in the absence of neurons. Lipopolysaccharide (LPS) increased cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNFα) mRNA expression with greater efficacy in DRG glial cell cultures than in mixed DRG cell cultures containing TLR4-positive neurons. Using an insert co-culture system, we have shown that neuronal inhibition of glial cell TLR4 is likely to be dependent on cell-cell contact rather than diffusible factors from neurons. LPS stimulated prostaglandin E2 (PGE2) production from DRG glial cells in a TLR4- and COX-2-dependent manner. In addition, exogenous PGE2 potentiated LPS-stimulated COX-2 mRNA while inhibiting TNFα mRNA expression by DRG cells, suggestive of a complex regulatory system to control inflammation within the DRG. In addition to LPS, conditioned medium from heat-shocked DRG neurons also increased COX-2 mRNA expression in DRG glial cells in a partially TLR4-dependent manner. We therefore hypothesize that neuronal suppression of glial TLR4 activity is a protective mechanism to prevent uncontrolled inflammation within the DRG. Under conditions where DRG neuronal viability is compromised, DRG glial cells become responsive to PAMPs (pathogen-associated molecular patterns) and DAMPs (danger-associated molecular patterns) and generate a range of classical inflammatory responses. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. The nigrostriatal pathway in the rat: A single-axon study of the relationship between dorsal and ventral tier nigral neurons and the striosome/matrix striatal compartments.

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    Prensa, L; Parent, A

    2001-09-15

    Axons from dorsal/ventral tiers of substantia nigra pars compacta (SNc), ventral tegmental area (VTA), and retrorubral field (RRF) were traced after injecting their cell body with biotinylated dextran amine. Fifty-three single axons were reconstructed from serial sagittal sections with a camera lucida, and mu-opiate receptor immunostaining served to differentiate the striosome/matrix striatal compartments. Most dorsal tier SNc axons terminate within the matrix of the dorsal striatum, but their patterns of arborization vary markedly; some axons innervate one specific matriceal area, whereas others arborize in multiple discontinuous loci. Some dorsal tier SNc axons also project to both striosomes and matrix. Other dorsal tier SNc axons, as well as VTA axons, innervate the ventral striatum and send collaterals to striosomes lying ventrally in the dorsal striatum or to the ventral sector of the subcallosal streak (SS). Ventral tier SNc axons arborize principally in striosomes, but some ramify in both compartments or in striosomes and the SS. Ventral tier neurons that form deep clusters in substantia nigra pars reticulata innervate principally the matrix and the SS. The amygdala and ventral pallidum receive secondary collaterals from striatal axons of dorsal/ventral tier neurons or RRF neurons. The subthalamic nucleus receives collaterals from striatal axons of SNc clustered neurons, whereas the globus pallidus gets collaterals from striatal axons of dorsal/ventral tier SNc neurons. These findings reveal that the nigrostriatal pathway is composed of several neuronal subsystems, each endowed with a widely distributed axonal arborization that allows them to exert a multifaceted influence on striatal and/or extrastriatal structures.

  6. A Population of Projection Neurons that Inhibits the Lateral Horn but Excites the Antennal Lobe through Chemical Synapses in Drosophila

    Directory of Open Access Journals (Sweden)

    Kazumichi Shimizu

    2017-05-01

    Full Text Available In the insect olfactory system, odor information is transferred from the antennal lobe (AL to higher brain areas by projection neurons (PNs in multiple AL tracts (ALTs. In several species, one of the ALTs, the mediolateral ALT (mlALT, contains some GABAergic PNs; in the Drosophila brain, the great majority of ventral PNs (vPNs are GABAergic and project through this tract to the lateral horn (LH. Most excitatory PNs (ePNs, project through the medial ALT (mALT to the mushroom body (MB and the LH. Recent studies have shown that GABAergic vPNs play inhibitory roles at their axon terminals in the LH. However, little is known about the properties and functions of vPNs at their dendritic branches in the AL. Here, we used optogenetic and patch clamp techniques to investigate the functional roles of vPNs in the AL. Surprisingly, our results show that specific activation of vPNs reliably elicits strong excitatory postsynaptic potentials (EPSPs in ePNs. Moreover, the connections between vPNs and ePNs are mediated by direct chemical synapses. Neither pulses of GABA, nor pharmagological, or genetic blockade of GABAergic transmission gave results consistent with the involvement of GABA in vPN-ePN excitatory transmission. These unexpected results suggest new roles for the vPN population in olfactory information processing.

  7. Advanced type 1 diabetes is associated with ASIC alterations in mouse lower thoracic dorsal root ganglia neurons.

    Science.gov (United States)

    Radu, Beatrice Mihaela; Dumitrescu, Diana Ionela; Marin, Adela; Banciu, Daniel Dumitru; Iancu, Adina Daniela; Selescu, Tudor; Radu, Mihai

    2014-01-01

    Acid-sensing ion channels (ASICs) from dorsal root ganglia (DRG) neurons are proton sensors during ischemia and inflammation. Little is known about their role in type 1 diabetes (T1D). Our study was focused on ASICs alterations determined by advanced T1D status. Primary neuronal cultures were obtained from lower (T9-T12) thoracic DRG neurons from Balb/c and TCR-HA(+/-)/Ins-HA(+/-) diabetic male mice (16 weeks of age). Patch-clamp recordings indicate a change in the number of small DRG neurons presenting different ASIC-type currents. Multiple molecular sites of ASICs are distinctly affected in T1D, probably due to particular steric constraints for glycans accessibility to the active site: (i) ASIC1 current inactivates faster, while ASIC2 is slower; (ii) PcTx1 partly reverts diabetes effects against ASIC1- and ASIC2-inactivations; (iii) APETx2 maintains unaltered potency against ASIC3 current amplitude, but slows ASIC3 inactivation. Immunofluorescence indicates opposite regulation of different ASIC transcripts while qRT-PCR shows that ASIC mRNA ranking (ASIC2 > ASIC1 > ASIC3) remains unaltered. In conclusion, our study has identified biochemical and biophysical ASIC changes in lower thoracic DRG neurons due to advanced T1D. As hypoalgesia is present in advanced T1D, ASICs alterations might be the cause or the consequence of diabetic insensate neuropathy.

  8. [Effects of blockade of 5-HT2A receptors in inflammatory site on complete Freund's adjuvant-induced chronic hyperalgesia and neuropeptide Y expression in the spinal dorsal horn in rats].

    Science.gov (United States)

    Huang, Bing-Qing; Wu, Bing; Hong, Yanguo; Hu, Wei

    2015-10-25

    5-hydroxytryptamine (5-HT) released in inflammatory tissues plays a pivotal role in pain hypersensitivity. However, it is not clear whether 5-HT2A receptors in the inflamed tissues mediate this effect. The present study investigated the contribution of 5-HT2A receptors in the periphery to chronic inflammatory pain. Complete Freund's adjuvant (CFA) was injected subcutaneously in the hindpaw of rats. The selective 5-HT2A receptor antagonist ketanserin was given in the inflamed site. Paw withdrawal latency responding to heat or mechanical stimuli was measured. Expression of neuropeptide Y (NPY) in the spinal dorsal horn and dorsal root ganglia (DRG) was assayed using immunohistochemistry technique. The results showed that ketanserin administered in the inflamed site inhibited thermal hyperalgesia in a dose-dependent manner (20, 40 and 80 µg) induced by the intraplantar injection of CFA. Ketanserin given once per day at a dose of 80 µg abolished heat hyperalgesia and also attenuated mechanical allodynia on the third day. CFA injection increased the expression of NPY in superficial laminae of the spinal cord, but not in the DRG. The local treatment of ketanserin completely inhibited CFA-induced increase in NPY expression in superficial laminae of the spinal cord. These results indicated that activation of 5-HT2A receptors in the inflamed tissues was involved in the pathogenesis of inflammatory pain and the blockade of 5-HT2A receptors in the periphery could relieve pain hypersensitivity and normalize the cellular disorder in the spinal dorsal horn associated with pathological pain. The present study suggests that the peripheral 5-HT2A receptors can be a promising target for pharmaceutical therapy to treat chronic inflammatory pain without central nervous system side effects.

  9. 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

  10. Prolonged sleep deprivation decreases cell proliferation and immature newborn neurons in both dorsal and ventral hippocampus of male rats.

    Science.gov (United States)

    Murata, Yusuke; Oka, Ayana; Iseki, Ayaka; Mori, Masayoshi; Ohe, Kenji; Mine, Kazunori; Enjoji, Munechika

    2017-09-01

    Previous studies have indicated that sleep deprivation negatively affects hippocampal neurogenesis, which may explain the reason for the relation between sleep loss and depression. Increasing evidence indicates that the hippocampus is anatomically and functionally segregated along a dorsolateral (cognitive function)/ventromedial (control for mood and stress response) axis. Thus, the present study was conducted to elucidate regional differences in the adverse effects of sleep deprivation on hippocampal neurogenesis. Male Sprague-Dawley rats were subjected to sleep deprivation using the "platform on the water" method for 24- or 72-h. Quantification of hippocampal cell proliferation and immature newborn neurons was stereologically estimated using immunostaining with Ki-67 and doublecortin (DCX), respectively, by optical fractionator method. A consecutive three days of sleep deprivation significantly reduced the density of Ki-67- and DCX-immunopositive cells both in the dorsal and ventral hippocampal subgranular zone and the decrease in DCX-labeled cells was more pronounced in the ventral hippocampus than in dorsal region. Our results indicate that prolonged sleep deprivation decreases hippocampal cell proliferation and neurogenesis in both the dorsal and ventral dentate gyrus. Future studies will be needed to clarify the impact of sleep deprivation-induced decreases in hippocampal neurogenesis on the development of depression. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

  11. Ventilation induced apnea and its effect on dorsal brainstem inspiratory neurones in the rat

    NARCIS (Netherlands)

    Subramanian, Hari H.; Balnave, Ron J.; Chow, Chin M.

    2007-01-01

    The purpose of this study was to examine the effect of mechanical ventilation (MV) on inherent breathing and on dorsal brainstem nucleus tractus solitarius (NTS) respiratory cell function. In pentobarbitone-anaesthetised rats, application of MV at combined high frequencies and volumes (representing

  12. Postsynaptic dorsal column neurons express NK1 receptors following colon inflammation

    Czech Academy of Sciences Publication Activity Database

    Paleček, Jiří; Palečková, V.; Willis, W. D.

    2003-01-01

    Roč. 116, č. 2 (2003), s. 565-572 ISSN 0306-4522 Grant - others:NIH(US) NS09743; NIH(US) NS11255 Institutional research plan: CEZ:AV0Z5011922 Keywords : visceral pain * substance P * postsynaptic dorsal column Subject RIV: FH - Neurology Impact factor: 3.601, year: 2003

  13. GABAergic Neurons of the Rat Dorsal Hippocampus Express Muscarinic Acetylcholine Receptors

    NARCIS (Netherlands)

    van der Zee, E.A.; Luiten, P.G.M.

    1993-01-01

    The expression of muscarinic acetylcholine receptors (mAChRs) in glutamic acid decarboxylase (GAD)-positive cells in the different strata of CA1, CA3, and the dentate gyrus (DG) of the dorsal hippocampus is examined by way of quantitative immunofluorescent double labeling employing M35, the

  14. Sialic acid accelerates the electrophoretic velocity of injured dorsal root ganglion neurons

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    Chen-xu Li

    2015-01-01

    Full Text Available Peripheral nerve injury has been shown to result in ectopic spontaneous discharges on soma and injured sites of sensory neurons, thereby inducing neuropathic pain. With the increase of membrane proteins on soma and injured site neurons, the negatively charged sialic acids bind to the external domains of membrane proteins, resulting in an increase of this charge. We therefore speculate that the electrophoretic velocity of injured neurons may be faster than non-injured neurons. The present study established rat models of neuropathic pain via chronic constriction injury. Results of the cell electrophoresis test revealed that the electrophoretic velocity of injured neuronal cells was faster than that of non-injured (control cells. We then treated cells with divalent cations of Ca 2+ and organic compounds with positive charges, polylysine to counteract the negatively charged sialic acids, or neuraminidase to specifically remove sialic acids from the membrane surface of injured neurons. All three treatments significantly reduced the electrophoretic velocity of injured neuronal cells. These findings suggest that enhanced sialic acids on injured neurons may accelerate the electrophoretic velocity of injured neurons.

  15. Modulators of calcium influx regulate membrane excitability in rat dorsal root ganglion neurons

    NARCIS (Netherlands)

    Lirk, Philipp; Poroli, Mark; Rigaud, Marcel; Fuchs, Andreas; Fillip, Patrick; Huang, Chun-Yuan; Ljubkovic, Marko; Sapunar, Damir; Hogan, Quinn

    2008-01-01

    Chronic neuropathic pain resulting from neuronal damage remains difficult to treat, in part, because of incomplete understanding of underlying cellular mechanisms. We have previously shown that inward Ca2+ flux (I(Ca)) across the sensory neuron plasmalemma is decreased in a rodent model of chronic

  16. Correlation of the electrophysiological profiles and sodium channel transcripts of individual rat dorsal root ganglia neurons

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    Olivier eTheriault

    2014-09-01

    Full Text Available Voltage gated sodium channels (Na+ channels play an important role in nociceptive transmission. They are intimately tied to the genesis and transmission of neuronal firing. Five different isoforms (Nav1.3, Nav1.6, Nav1.7, Nav1.8, and Nav1.9 have been linked to nociceptive responses. A change in the biophysical properties of these channels or in their expression levels occurs in different pathological pain states. However, the precise involvement of the isoforms in the genesis and transmission of nociceptive responses is unknown. The aim of the present study was to investigate the synergy between the different populations Na+ channels that give individual neurons a unique electrophysical profile.We used the patch-clamp technique in the whole-cell configuration to record Na+ currents and action potentials from acutely dissociated small diameter DRG neurons (<30 µM from adult rats. We also performed single cell qPCR on the same neurons. Our results revealed that there is a strong correlation between Na+ currents and mRNA transcripts in individual neurons. A cluster analysis showed that subgroups formed by Na+ channel transcripts by mRNA quantification have different biophysical properties. In addition, the firing frequency of the neurons was not affected by the relative populations of Na+ channel. The synergy between populations of Na+ channel in individual small diameter DRG neurons gives each neuron a unique electrophysiological profile. The Na+ channel remodeling that occurs in different pathological pain states may be responsible for the sensitization of the neurons.

  17. Shp-1 dephosphorylates TRPV1 in dorsal root ganglion neurons and alleviates CFA-induced inflammatory pain in rats.

    Science.gov (United States)

    Xiao, Xing; Zhao, Xiao-Tao; Xu, Ling-Chi; Yue, Lu-Peng; Liu, Feng-Yu; Cai, Jie; Liao, Fei-Fei; Kong, Jin-Ge; Xing, Guo-Gang; Yi, Ming; Wan, You

    2015-04-01

    Transient receptor potential vanilloid 1 (TRPV1) receptors are expressed in nociceptive neurons of rat dorsal root ganglions (DRGs) and mediate inflammatory pain. Nonspecific inhibition of protein-tyrosine phosphatases (PTPs) increases the tyrosine phosphorylation of TRPV1 and sensitizes TRPV1. However, less is known about tyrosine phosphorylation's implication in inflammatory pain, compared with that of serine/threonine phosphorylation. Src homology 2 domain-containing tyrosine phosphatase 1 (Shp-1) is a key phosphatase dephosphorylating TRPV1. In this study, we reported that Shp-1 colocalized with and bound to TRPV1 in nociceptive DRG neurons. Shp-1 inhibitors, including sodium stibogluconate and PTP inhibitor III, sensitized TRPV1 in cultured DRG neurons. In naive rats, intrathecal injection of Shp-1 inhibitors increased both TRPV1 and tyrosine-phosphorylated TRPV1 in DRGs and induced thermal hyperalgesia, which was abolished by pretreatment with TRPV1 antagonists capsazepine, BCTC, or AMG9810. Complete Freund's adjuvant (CFA)-induced inflammatory pain in rats significantly increased the expression of Shp-1, TRPV1, and tyrosine-phosphorylated TRPV1, as well as the colocalization of Shp-1 and TRPV1 in DRGs. Intrathecal injection of sodium stibogluconate aggravated CFA-induced inflammatory pain, whereas Shp-1 overexpression in DRG neurons alleviated it. These results suggested that Shp-1 dephosphorylated and inhibited TRPV1 in DRG neurons, contributing to maintain thermal nociceptive thresholds in normal rats, and as a compensatory mechanism, Shp-1 increased in DRGs of rats with CFA-induced inflammatory pain, which was involved in protecting against excessive thermal hyperalgesia.

  18. Lack of evidence for sprouting of Aβ afferents into the superficial laminas of the spinal cord dorsal horn after nerve section

    OpenAIRE

    Hughes, D.I.; Scott, D.T.; Todd, A.J.; Riddell, J.S.

    2003-01-01

    The central arborizations of large myelinated cutaneous afferents normally extend as far dorsally as the ventral part of lamina II in rat spinal cord. Woolf et al. (1992) reported that after nerve injury some of these afferents sprouted into lamina I and the dorsal part of lamina II, and it has been suggested that this could contribute to allodynia associated with neuropathic pain. Part of the evidence for sprouting was on the basis of the use of cholera toxin B subunit as a selective tracer ...

  19. 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.

  20. 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...

  1. Kv4 channels underlie the subthreshold-operating A-type K+-current in nociceptive dorsal root ganglion neurons

    Directory of Open Access Journals (Sweden)

    Thanawath R Na Phuket

    2009-07-01

    Full Text Available The dorsal root ganglion (DRG contains heterogeneous populations of sensory neurons including primary nociceptive neurons and C-fibers implicated in pain signaling.  Recent studies have demonstrated DRG hyperexcitability associated with downregulation of A-type K+ channels; however, the molecular correlate of the corresponding A-type K+ current (IA has remained hypothetical.  Kv4 channels may underlie the IA in DRG neurons.  We combined electrophysiology, molecular biology (whole-tissue and single-cell RT-PCR and immunohistochemistry to investigate the molecular basis of the IA in acutely dissociated DRG neurons from 7-8 day-old rats.  Whole-cell recordings demonstrate a robust tetraethylammonium-resistant (20 mM and 4-aminopyridine-sensitive (5 mM IA.  Matching Kv4 channel properties, activation and inactivation of this IA occur in the subthreshold range of membrane potentials and the rate of recovery from inactivation is rapid and voltage-dependent.  Among Kv4 transcripts, the DRG expresses significant levels of Kv4.1 and Kv4.3 mRNAs.  Also, single small-medium diameter DRG neurons (~30 mm exhibit correlated frequent expression of mRNAs encoding Kv4.1 and Nav1.8, a known nociceptor marker.  In contrast, the expressions of Kv1.4 and Kv4.2 mRNAs at the whole-tissue and single-cell levels are relatively low and infrequent.  Kv4 protein expression in nociceptive DRG neurons was confirmed by immunohistochemistry, which demonstrates colocalization of Kv4.3 and Nav1.8, and negligible expression of Kv4.2.  Furthermore, specific dominant-negative suppression and overexpression strategies confirmed the contribution of Kv4 channels to IA in DRG neurons.  Contrasting the expression patterns of Kv4 channels in the central and peripheral nervous systems, we discuss possible functional roles of these channels in primary sensory neurons.

  2. MEF2C Haploinsufficiency features consistent hyperkinesis, variable epilepsy, and has a role in dorsal and ventral neuronal developmental pathways

    Science.gov (United States)

    Paciorkowski, Alex R.; Traylor, Ryan N.; Rosenfeld, Jill A.; Hoover, Jacqueline M.; Harris, Catharine J.; Winter, Susan; Lacassie, Yves; Bialer, Martin; Lamb, Allen N.; Schultz, Roger A.; Berry-Kravis, Elizabeth; Porter, Brenda E.; Falk, Marni; Venkat, Anu; Vanzo, Rena J.; Cohen, Julie S.; Fatemi, Ali; Dobyns, William B.; Shaffer, Lisa G.; Ballif, Blake C.; Marsh, Eric D.

    2013-01-01

    MEF2C haploinsufficiency syndrome is an emerging neurodevelopmental disorder associated with intellectual disability, autistic features, epilepsy, and abnormal movements. We report 16 new patients with MEF2C haploinsufficiency, including the oldest reported patient with MEF2C deletion at 5q14.3. We detail the neurobehavioral phenotype, epilepsy, and abnormal movements, and compare our subjects with those previously reported in the literature. We also investigate Mef2c expression in the developing mouse forebrain. A spectrum of neurofunctional deficits emerges, with hyperkinesis a consistent finding. Epilepsy varied from absent to severe, and included intractable myoclonic seizures and infantile spasms. Subjects with partial MEF2C deletion were statistically less likely to have epilepsy. Finally, we confirm that Mef2c is present both in dorsal primary neuroblasts and ventral gamma-aminobutyric acid(GABA)ergic interneurons in the forebrain of the developing mouse. Given interactions with several key neurodevelopmental genes such as ARX, FMR1, MECP2, and TBR1, it appears that MEF2C plays a role in several developmental stages of both dorsal and ventral neuronal cell types. PMID:23389741

  3. Cadherin-13 Deficiency Increases Dorsal Raphe 5-HT Neuron Density and Prefrontal Cortex Innervation in the Mouse Brain

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    Andrea Forero

    2017-09-01

    Full Text Available Background: During early prenatal stages of brain development, serotonin (5-HT-specific neurons migrate through somal translocation to form the raphe nuclei and subsequently begin to project to their target regions. The rostral cluster of cells, comprising the median and dorsal raphe (DR, innervates anterior regions of the brain, including the prefrontal cortex. Differential analysis of the mouse 5-HT system transcriptome identified enrichment of cell adhesion molecules in 5-HT neurons of the DR. One of these molecules, cadherin-13 (Cdh13 has been shown to play a role in cell migration, axon pathfinding, and synaptogenesis. This study aimed to investigate the contribution of Cdh13 to the development of the murine brain 5-HT system.Methods: For detection of Cdh13 and components of the 5-HT system at different embryonic developmental stages of the mouse brain, we employed immunofluorescence protocols and imaging techniques, including epifluorescence, confocal and structured illumination microscopy. The consequence of CDH13 loss-of-function mutations on brain 5-HT system development was explored in a mouse model of Cdh13 deficiency.Results: Our data show that in murine embryonic brain Cdh13 is strongly expressed on 5-HT specific neurons of the DR and in radial glial cells (RGCs, which are critically involved in regulation of neuronal migration. We observed that 5-HT neurons are intertwined with these RGCs, suggesting that these neurons undergo RGC-guided migration. Cdh13 is present at points of intersection between these two cell types. Compared to wildtype controls, Cdh13-deficient mice display increased cell densities in the DR at embryonic stages E13.5, E17.5, and adulthood, and higher serotonergic innervation of the prefrontal cortex at E17.5.Conclusion: Our findings provide evidence for a role of CDH13 in the development of the serotonergic system in early embryonic stages. Specifically, we indicate that Cdh13 deficiency affects the cell

  4. Primary afferent terminal sprouting after a cervical dorsal rootlet section in the macaque monkey.

    Science.gov (United States)

    Darian-Smith, Corinna

    2004-03-01

    We examined the role of primary afferent neurons in the somatosensory cortical "reactivation" that occurs after a localized cervical dorsal root lesion (Darian-Smith and Brown [2000] Nat. Neurosci. 3:476-481). After section of the dorsal rootlets that enervate the macaque's thumb and index finger (segments C6-C8), the cortical representation of these digits was initially silenced but then re-emerged for these same digits over 2-4 postlesion months. Cortical reactivation was accompanied by the emergence of physiologically detectable input from these same digits within dorsal rootlets bordering the lesion site. We investigated whether central axonal sprouting of primary afferents spared by the rhizotomy could mediate this cortical reactivation. The cortical representation of the hand was mapped electrophysiologically 15-25 weeks after the dorsal rootlet section to define this reactivation. Cholera toxin subunit B conjugated to horseradish peroxidase was then injected into the thumb and index finger pads bilaterally to label the central terminals of any neurons that innervated these digits. Primary afferent terminal proliferation was assessed in the spinal dorsal horn and cuneate nucleus at 7 days and 15-25 postlesion weeks. Labeled terminal bouton distributions were reconstructed and the "lesion" and control sides compared within each monkey. Distributions were significantly larger on the side of the lesion in the dorsal horn and cuneate nucleus at 15-25 weeks after the dorsal rootlet section, than those mapped only 7 days postlesion. Our results provide direct evidence for localized sprouting of spared (uninjured) primary afferent terminals in the dorsal horn and cuneate nucleus after a restricted dorsal root injury. Copyright 2004 Wiley-Liss, Inc.

  5. Gastrointestinal-projecting neurones in the dorsal motor nucleus of the vagus exhibit direct and viscerotopically organized sensitivity to orexin

    Science.gov (United States)

    Grabauskas, Gintautas; Moises, Hylan C

    2003-01-01

    Orexin (hypocretin)-containing projections from lateral hypothalamus (LH) are thought to play an important role in the regulation of feeding behaviour and energy balance. In rodent studies, central administration of orexin peptides increases food intake, and orexin neurones in the LH are activated by hypoglycaemia during fasting. In addition, administration of orexins into the fourth ventricle or the dorsal motor nucleus of the vagus (DMV) has been shown to stimulate gastric acid secretion and motility, respectively, via vagal efferent pathways. In this study, whole-cell recordings were obtained from DMV neurones in rat brainstem slices to investigate the cellular mechanism(s) by which orexins produce their gastrostimulatory effects. To determine whether responsiveness to orexins might be differentially expressed among distinct populations of preganglionic vagal motor neurones, recordings were made from neurones whose projections to the gastrointestinal tract had been identified by retrograde labelling following apposition of the fluorescent tracer DiI to the gastric fundus, corpus or antrum/pylorus, the duodenum or caecum. Additionally, the responses of neurones to orexins were compared with those produced by oxytocin, which acts within the DMV to stimulate gastric acid secretion, but inhibits gastric motor function. Bath application of orexin-A or orexin-B (30–300 nm) produced a slow depolarization, accompanied by increased firing in 47 of 102 DMV neurones tested, including 70 % (30/43) of those that projected to the gastric fundus or corpus. In contrast, few DMV neurones that supplied the antrum/pylorus (3/13), duodenum (4/18) or caecum (1/13) were responsive to these peptides. The depolarizing responses were concentration dependent and persisted during synaptic isolation of neurones with TTX or Cd2+, indicating they resulted from activation of postsynaptic orexin receptors. They were also associated with a small increase in membrane resistance, and in voltage

  6. Dissociable effects of dopamine on neuronal firing rate and synchrony in the dorsal striatum

    Directory of Open Access Journals (Sweden)

    John M Burkhardt

    2009-10-01

    Full Text Available Previous studies showed that dopamine depletion leads to both changes in firing rate and in neuronal synchrony in the basal ganglia. Since dopamine D1 and D2 receptors are preferentially expressed in striatonigral and striatopallidal medium spiny neurons, respectively, we investigated the relative contribution of lack of D1 and/or D2-type receptor activation to the changes in striatal firing rate and synchrony observed after dopamine depletion. Similar to what was observed after dopamine depletion, co-administration of D1 and D2 antagonists to mice chronically implanted with multielectrode arrays in the striatum caused significant changes in firing rate, power of the local field potential (LFP oscillations, and synchrony measured by the entrainment of neurons to striatal local field potentials. However, although blockade of either D1 or D2 type receptors produced similarly severe akinesia, the effects on neural activity differed. Blockade of D2 receptors affected the firing rate of medium spiny neurons and the power of the LFP oscillations substantially, but it did not affect synchrony to the same extent. In contrast, D1 blockade affected synchrony dramatically, but had less substantial effects on firing rate and LFP power. Furthermore, there was no consistent relation between neurons changing firing rate and changing LFP entrainment after dopamine blockade. Our results suggest that the changes in rate and entrainment to the LFP observed in medium spiny neurons after dopamine depletion are somewhat dissociable, and that lack of D1- or D2-type receptor activation can exert independent yet interactive pathological effects during the progression of Parkinson’s disease.

  7. Muscarinic receptor activation enables persistent firing in pyramidal neurons from superficial layers of dorsal perirhinal cortex.

    Science.gov (United States)

    Navaroli, Vicky L; Zhao, Yanjun; Boguszewski, Pawel; Brown, Thomas H

    2012-06-01

    Persistent-firing neurons in the entorhinal cortex (EC) and the lateral nucleus of the amygdala (LA) continue to discharge long after the termination of the original, spike-initiating current. An emerging theory proposes that endogenous persistent firing helps support a transient memory system. This study demonstrated that persistent-firing neurons are also prevalent in rat perirhinal cortex (PR), which lies immediately adjacent to and is reciprocally connected with EC and LA. Several characteristics of persistent-firing neurons in PR were similar to those previously reported in LA and EC. Persistent firing in PR was enabled by the application of carbachol, a nonselective cholinergic agonist, and it was induced by injecting a suprathreshold current or by stimulating suprathreshold excitatory synaptic inputs to the neuron. Once induced, persistent firing lasted for seconds to minutes. Persistent firing could always be terminated by a sufficiently large and prolonged hyperpolarizing current; it was prevented by antagonists of muscarinic cholinergic receptors (mAChRs); and it was blocked by flufenamic acid. The latter has been suggested to inhibit a Ca(2+) -activated nonspecific cation conductance (G(CAN) ) that normally furnishes the sustained depolarization during persistent firing. In many PR neurons, the discharge rate during persistent firing was a graded function of depolarizing and/or hyperpolarizing inputs. Persistent firing was not prevented by blocking fast excitatory and inhibitory synaptic transmission, demonstrating that it can be generated endogenously. We suggest that persistent-firing neurons in PR, EC, LA, and certain other brain regions may cooperate in support of a transient-memory system. Copyright © 2011 Wiley Periodicals, Inc.

  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

    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 ...

  9. Differential Expression of Tubulin Acetylase and Deacetylase Between the Damaged Central and Peripheral Branch of Dorsal Root Ganglion Neurons.

    Science.gov (United States)

    Fu, Zhiyi; Shi, Jiangang

    2017-07-28

    BACKGROUND The differences between the peripheral and central branches of the dorsal root ganglion (DRG) have not been fully elucidated. This study aimed to explore the expression of tubulin post-translational modifications (acetylation and deacetylation) between damaged peripheral and central branches of DRG neurons. MATERIAL AND METHODS Fifty Sprague-Dawley rats were randomly assigned to five groups with 10 rats in each group. These five groups consisted of spinal nerve ligation (SNL) at 24 hour and 48 hour, and cauda equina compression (CEC) at 24 hour and 48 hour, and a sham group. SNL injury in rats was induced by ligating L5 and L6 spinal nerves with 1-0 silk thread outboard the DRGs. CEC injury in rats was induced by a piece of silicone (10×1×1 mm) placed under the laminae of the L5-6 vertebra. Sham-operated rats underwent a simple laminectomy in L4, but silicone was not implanted. The expression profile of acetylase and deacetylase was examined by real-time PCR, Western blotting, and immunohistochemistry. RESULTS In the experimental groups, rats presented increased expression of acetylase (NAT1 and MEC-17) and decreased expression of deacetylase (Sirt2 and HDAC6) levels. Additionally, the expression of NAT1 and MEC-17 was gradually increased in DRG neurons following peripheral axonal injury compared to central axonal injury in a time-dependent manner. Conversely, the expression of Sirt2 and HDAC6 was gradually decreased in DRG neurons following peripheral axonal injury compared to central axonal injury in a time-dependent manner. CONCLUSIONS Our study indicated that insufficiency of acetylase and upregulation of deacetylase in DRG neurons after central axonal injury may contribute to the pathogenesis of cauda equine syndrome.

  10. Rhythmic activity of feline dorsal and ventral spinocerebellar tract neurons during fictive motor actions

    DEFF Research Database (Denmark)

    Fedirchuk, Brent; Stecina, Katinka; Kristensen, Kasper Kyhl

    2013-01-01

    nerves. Spinocerebellar tract cells with cell bodies located in the lumbar segments were identified by electrophysiological techniques and examined by extra- and intracellular microelectrode recordings. During fictive locomotion, 57/81 DSCT and 30/30 VSCT neurons showed phasic, cycle-related activity...

  11. Exposure to an open-field arena increases c-Fos expression in a subpopulation of neurons in the dorsal raphe nucleus, including neurons projecting to the basolateral amygdaloid complex

    DEFF Research Database (Denmark)

    Hale, M.W.; Hay-Schmidt, A.; Mikkelsen, J.D.

    2008-01-01

    Serotonergic systems in the dorsal raphe nucleus are thought to play an important role in the regulation of anxiety states. To investigate responses of neurons in the dorsal raphe nucleus to a mild anxiety-related stimulus, we exposed rats to an open-field, under low-light or high-light conditions...... of neurons in the midbrain raphe complex that projects to forebrain circuits regulating anxiety states, we used cholera toxin B subunit (CTb) as a retrograde tracer to identify neurons projecting to the basolateral amygdaloid complex (BL) in combination with c-Fos immunostaining to identify cells...... that activated neurons were serotonergic, non-serotonergic, or both. These data are consistent with the hypothesis that exposure to anxiogenic stimuli activates a subset of neurons in the midbrain raphe complex projecting to amygdala anxiety circuits Udgivelsesdato: 2008/12/10...

  12. Mechanical Compression and Nucleus Pulposus Application on Dorsal Root Ganglia Differentially Modify Evoked Neuronal Activity in the Thalamus

    Science.gov (United States)

    Nilsson, Elin; Brisby, Helena; Rask, Katarina

    2013-01-01

    Abstract A combination of mechanical compression caused by a protruding disc and leakage of nucleus pulposus (NP) from the disc core is presumed to contribute to intervertebral disc hernia-related pain. Experimental models of disc hernia including both components have resulted in changes in neuronal activity at the level of the dorsal root ganglion (DRG) and spinal cord, but changes within the brain have been less well studied. However, acute application of NP to a DRG without mechanical compression rapidly increases neuronal activity in the thalamus, a major brain relay nucleus processing information from sensory pathways including ascending nociceptive tracts. The combination of mechanical compression and NP might therefore result in further increases in central neuronal activity. Using an experimental disc herniation rat model including both mechanical compression and NP the present study aimed to investigate changes in neuronal activity in the contralateral thalamic ventral posterior lateral nucleus in vivo. Measurements were obtained while electrically stimulating the ipsilateral sciatic nerve at Aδ fiber intensities. The L4 DRG was subjected to light mechanical compression and NP exposure, and acute changes in evoked thalamic responses were recorded for up to 40 min. In order to compare effects in naïve animals with effects following a longer period of NP exposure, animals that were either disc-punctured or sham-operated 24 h previously were also included. In all animals, light mechanical compression of the DRG depressed the number of evoked neuronal responses. Prior NP exposure resulted in less potent changes following mechanical compression (80% of baseline) than that observed in naïve animals (50%). During the subsequent NP application, the number of evoked responses compared to baseline increased in pre-exposed animals (to 87%) as well as in naïve animals (72%) in which the removal of the mechanical compression resulted in a further increase (106

  13. Impaired Chemosensitivity of Mouse Dorsal Raphe Serotonergic Neurons Overexpressing Serotonin 1A (Htr1a) Receptors

    OpenAIRE

    Baccini, Gilda; Mlinar, Boris; Audero, Enrica; Gross, Cornelius Thilo; Corradetti, Renato

    2012-01-01

    BACKGROUND: Serotonergic system participates in a wide range of physiological processes and behaviors, but its role is generally considered as modulatory and noncrucial, especially concerning life-sustaining functions. We recently created a transgenic mouse line in which a functional deficit in serotonin homeostasis due to excessive serotonin autoinhibition was produced by inducing serotonin 1A receptor (Htr1a) overexpression selectively in serotonergic neurons (Htr1a raphe-overexpressing or ...

  14. Dorsal Medial Habenula Regulation of Mood-Related Behaviors and Primary Reinforcement by Tachykinin-Expressing Habenula Neurons.

    Science.gov (United States)

    Hsu, Yun-Wei A; Morton, Glenn; Guy, Elizabeth G; Wang, Si D; Turner, Eric E

    2016-01-01

    Animal models have been developed to investigate aspects of stress, anxiety, and depression, but our understanding of the circuitry underlying these models remains incomplete. Prior studies of the habenula, a poorly understood nucleus in the dorsal diencephalon, suggest that projections to the medial habenula (MHb) regulate fear and anxiety responses, whereas the lateral habenula (LHb) is involved in the expression of learned helplessness, a model of depression. Tissue-specific deletion of the transcription factor Pou4f1 in the dorsal MHb (dMHb) results in a developmental lesion of this subnucleus. These dMHb-ablated mice show deficits in voluntary exercise, a possible correlate of depression. Here we explore the role of the dMHb in mood-related behaviors and intrinsic reinforcement. Lesions of the dMHb do not elicit changes in contextual conditioned fear. However, dMHb-lesioned mice exhibit shorter immobility time in the tail suspension test, another model of depression. dMHb-lesioned mice also display increased vulnerability to the induction of learned helplessness. However, this effect is not due specifically to the dMHb lesion, but appears to result from Pou4f1 haploinsufficiency elsewhere in the nervous system. Pou4f1 haploinsufficiency does not produce the other phenotypes associated with dMHb lesions. Using optogenetic intracranial self-stimulation, intrinsic reinforcement by the dMHb can be mapped to a specific population of neurokinin-expressing habenula neurons. Together, our data show that the dMHb is involved in the regulation of multiple mood-related behaviors, but also support the idea that these behaviors do not reflect a single functional pathway.

  15. Median and Dorsal Raphe Serotonergic Neurons Control Moderate Versus Compulsive Cocaine Intake.

    Science.gov (United States)

    Verheij, Michel M M; Contet, Candice; Karel, Peter; Latour, Judith; van der Doelen, Rick H A; Geenen, Bram; van Hulten, Josephus A; Meyer, Francisca; Kozicz, Tamas; George, Olivier; Koob, George F; Homberg, Judith R

    2017-11-20

    Reduced expression of the serotonin transporter (SERT) promotes anxiety and cocaine intake in both humans and rats. We tested the hypothesis that median raphe nucleus (MRN) and dorsal raphe nucleus (DRN) serotonergic projections differentially mediate these phenotypes. We used virally mediated RNA interference to locally downregulate SERT expression and compared the results with those of constitutive SERT knockout. Rats were allowed either short access (ShA) (1 hour) or long access (LgA) (6 hours) to cocaine self-administration to model moderate versus compulsive-like cocaine taking. SERT knockdown in the MRN increased cocaine intake selectively under ShA conditions and, like ShA cocaine self-administration, reduced corticotropin-releasing factor (CRF) immunodensity in the paraventricular nucleus of the hypothalamus. In contrast, SERT knockdown in the DRN increased cocaine intake selectively under LgA conditions and, like LgA cocaine self-administration, reduced CRF immunodensity in the central nucleus of the amygdala. SERT knockdown in the MRN or DRN produced anxiety-like behavior, as did withdrawal from ShA or LgA cocaine self-administration. The phenotype of SERT knockout rats was a summation of the phenotypes generated by MRN- and DRN-specific SERT knockdown. Our results highlight a differential role of serotonergic projections arising from the MRN and DRN in the regulation of cocaine intake. We propose that a cocaine-induced shift from MRN-driven serotonergic control of CRF levels in the hypothalamus to DRN-driven serotonergic control of CRF levels in the amygdala may contribute to the transition from moderate to compulsive intake of cocaine. Copyright © 2017 Society of Biological Psychiatry. All rights reserved.

  16. 7, 8, 3′-Trihydroxyflavone Promotes Neurite Outgrowth and Protects Against Bupivacaine-Induced Neurotoxicity in Mouse Dorsal Root Ganglion Neurons

    Science.gov (United States)

    Shi, Haohong; Luo, Xingjing

    2016-01-01

    Background 7, 8, 3′-trihydroxyflavone (THF) is a novel pro-neuronal small molecule that acts as a TrkB agonist. In this study, we examined the effect of THF on promoting neuronal growth and protecting anesthetics-induced neurotoxicity in dorsal root ganglion (DRG) neurons in vitro. Material/Methods Neonatal mouse DRG neurons were cultured in vitro and treated with various concentrations of THF. The effect of THF on neuronal growth was investigated by neurite outgrowth assay and Western blot. In addition, the protective effects of THF on bupivacaine-induced neurotoxicity were investigated by apoptosis TUNEL assay, neurite outgrowth assay, and Western blot, respectively. Results THF promoted neurite outgrowth of DRG neurons in dose-dependent manner, with an EC50 concentration of 67.4 nM. Western blot analysis showed THF activated TrkB signaling pathway by inducing TrkB phosphorylation. THF also rescued bupivacaine-induced neurotoxicity by reducing apoptosis and protecting neurite retraction in DRG neurons. Furthermore, the protection of THF in bupivacaine-injured neurotoxicity was directly associated with TrkB phosphorylation in a concentration-dependent manner in DRG neurons. Conclusions THF has pro-neuronal effect on DRG neurons by promoting neurite growth and protecting against bupivacaine-induced neurotoxicity, likely through TrkB activation. PMID:27371503

  17. Chronic recruitment of primary afferent neurons by microstimulation in the feline dorsal root ganglia

    Science.gov (United States)

    Fisher, Lee E.; Ayers, Christopher A.; Ciollaro, Mattia; Ventura, Valérie; Weber, Douglas J.; Gaunt, Robert A.

    2014-06-01

    Objective. This study describes results of primary afferent neural microstimulation experiments using microelectrode arrays implanted chronically in the lumbar dorsal root ganglia (DRG) of four cats. The goal was to test the stability and selectivity of these microelectrode arrays as a potential interface for restoration of somatosensory feedback after damage to the nervous system such as amputation. Approach. A five-contact nerve-cuff electrode implanted on the sciatic nerve was used to record the antidromic compound action potential response to DRG microstimulation (2-15 µA biphasic pulses, 200 µs cathodal pulse width), and the threshold for eliciting a response was tracked over time. Recorded responses were segregated based on conduction velocity to determine thresholds for recruiting Group I and Group II/Aβ primary afferent fibers. Main results. Thresholds were initially low (5.1 ± 2.3 µA for Group I and 6.3 ± 2.0 µA for Group II/Aβ) and increased over time. Additionally the number of electrodes with thresholds less than or equal to 15 µA decreased over time. Approximately 12% of tested electrodes continued to elicit responses at 15 µA up to 26 weeks after implantation. Higher stimulation intensities (up to 30 µA) were tested in one cat at 23 weeks post-implantation yielding responses on over 20 additional electrodes. Within the first six weeks after implantation, approximately equal numbers of electrodes elicited only Group I or Group II/Aβ responses at threshold, but the relative proportion of Group II/Aβ responses decreased over time. Significance. These results suggest that it is possible to activate Group I or Group II/Aβ primary afferent fibers in isolation with penetrating microelectrode arrays implanted in the DRG, and that those responses can be elicited up to 26 weeks after implantation, although it may be difficult to achieve a consistent response day-to-day with currently available electrode technology. The DRG are compelling targets

  18. One cell model establishment to inhibit CaMKIIγmRNA expression in the dorsal root ganglion neuron by RNA interfere.

    Science.gov (United States)

    Wen, Xianjie; Li, Xiaohong; Liang, Hua; Yang, Chenxiang; Zhong, Jiying; Wang, Hanbing; Liu, Hongzhen

    2017-09-01

    CaMKII γ in dorsal root ganglion neurons is closely related to the neuropathic pain, neuron injury induced by local anesthetics. To get great insight into the function of CaMKII γ in dorsal root ganglion neurons, we need one cell model to specially inhibit the CaMKII γ mRNA expression. The present study was aimed to establish one cell model to specially inhibit the CaMKII γ mRNA expression. We designed the CaMKII γ shRNA sequence and connected with pYr-1.1 plasmid. The ligation product of the CaMKII γ shRNA and pYr-1.1 plasmid was recombined with pAd/PL-DEST vector into pAD-CaMKIIγ-shRNA. adenovirus vector. pAD-CaMKIIγ-shRNA. adenovirus vector infected the dorsal root ganglion neuron to inhibit the CaMKII γ mRNA expression in vitro. The pAD-CaMKIIγ-shRNA adenovirus vector was verified to be correct by the digestion, sequence. And pAD-CaMKIIγ-shRNA. adenovirus vector can infect the DRG cells to inhibit the CaMKII γ mRNA or protein expression by the real-time polymerase chain reaction (PCR) or western blotting. Those results showed that we successfully constructed one adenovirus vector that can infect the dorsal root ganglion neuron to inhibit the CaMKII γ mRNA and protein expression. That will supply with one cell model for the CaMKII γ function study.

  19. α-Dendrotoxin inhibits the ASIC current in dorsal root ganglion neurons from rat.

    Science.gov (United States)

    Báez, Adriana; Salceda, Emilio; Fló, Martín; Graña, Martín; Fernández, Cecilia; Vega, Rosario; Soto, Enrique

    2015-10-08

    Dendrotoxins are a group of peptide toxins purified from the venom of several mamba snakes. α-Dendrotoxin (α-DTx, from the Eastern green mamba Dendroaspis angusticeps) is a well-known blocker of voltage-gated K(+) channels and specifically of K(v)1.1, K(v)1.2 and K(v)1.6. In this work we show that α-DTx inhibited the ASIC currents in DRG neurons (IC50=0.8 μM) when continuously perfused during 25 s (including a 5 s pulse to pH 6.1), but not when co-applied with the pH drop. Additionally, we show that α-DTx abolished a transient component of the outward current that, in some experiments, appeared immediately after the end of the acid pulse. Our data indicate that α-DTx inhibits ASICs in the high nM range while some Kv are inhibited in the low nM range. The α-DTx selectivity and its potential interaction with ASICs should be taken in consideration when DTx is used in the high nM range. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Inhibitory Activity of Yokukansankachimpihange against Nerve Growth Factor-Induced Neurite Growth in Cultured Rat Dorsal Root Ganglion Neurons

    Directory of Open Access Journals (Sweden)

    Chiaki Murayama

    2015-08-01

    Full Text Available Chronic pruritus is a major and distressing symptom of many cutaneous diseases, however, the treatment remains a challenge in the clinic. The traditional Chinese-Japanese medicine (Kampo medicine is a conservative and increasingly popular approach to treat chronic pruritus for both patients and medical providers. Yokukansankachimpihange (YKH, a Kampo formula has been demonstrated to be effective in the treatment of itching of atopic dermatitis in Japan although its pharmacological mechanism is unknown clearly. In an attempt to clarify its pharmacological actions, in this study, we focused on the inhibitory activity of YKH against neurite growth induced with nerve growth factor (NGF in cultured rat dorsal root ganglion (DRG neurons because epidermal hyperinnervation is deeply related to itch sensitization. YKH showed approximately 200-fold inhibitory activity against NGF-induced neurite growth than that of neurotropin (positive control, a drug used clinically for treatment of chronic pruritus. Moreover, it also found that Uncaria hook, Bupleurum root and their chemical constituents rhynchophylline, hirsutine, and saikosaponin a, d showed inhibitory activities against NGF-induced neurite growth, suggesting they should mainly contribute to the inhibitory activity of YKH. Further study on the effects of YKH against epidermal nerve density in “itch-scratch” animal models is under investigation.

  1. Preictal activity of subicular, CA1, and dentate gyrus principal neurons in the dorsal hippocampus before spontaneous seizures in a rat model of temporal lobe epilepsy.

    Science.gov (United States)

    Fujita, Satoshi; Toyoda, Izumi; Thamattoor, Ajoy K; Buckmaster, Paul S

    2014-12-10

    Previous studies suggest that spontaneous seizures in patients with temporal lobe epilepsy might be preceded by increased action potential firing of hippocampal neurons. Preictal activity is potentially important because it might provide new opportunities for predicting when a seizure is about to occur and insight into how spontaneous seizures are generated. We evaluated local field potentials and unit activity of single, putative excitatory neurons in the subiculum, CA1, CA3, and dentate gyrus of the dorsal hippocampus in epileptic pilocarpine-treated rats as they experienced spontaneous seizures. Average action potential firing rates of neurons in the subiculum, CA1, and dentate gyrus, but not CA3, increased significantly and progressively beginning 2-4 min before locally recorded spontaneous seizures. In the subiculum, CA1, and dentate gyrus, but not CA3, 41-57% of neurons displayed increased preictal activity with significant consistency across multiple seizures. Much of the increased preictal firing of neurons in the subiculum and CA1 correlated with preictal theta activity, whereas preictal firing of neurons in the dentate gyrus was independent of theta. In addition, some CA1 and dentate gyrus neurons displayed reduced firing rates preictally. These results reveal that different hippocampal subregions exhibit differences in the extent and potential underlying mechanisms of preictal activity. The finding of robust and significantly consistent preictal activity of subicular, CA1, and dentate neurons in the dorsal hippocampus, despite the likelihood that many seizures initiated in other brain regions, suggests the existence of a broader neuronal network whose activity changes minutes before spontaneous seizures initiate. Copyright © 2014 the authors 0270-6474/14/3416671-17$15.00/0.

  2. Neuronal Subtype and Satellite Cell Tropism Are Determinants of Varicella-Zoster Virus Virulence in Human Dorsal Root Ganglia Xenografts In Vivo.

    Directory of Open Access Journals (Sweden)

    Leigh Zerboni

    2015-06-01

    Full Text Available Varicella zoster virus (VZV, a human alphaherpesvirus, causes varicella during primary infection. VZV reactivation from neuronal latency may cause herpes zoster, post herpetic neuralgia (PHN and other neurologic syndromes. To investigate VZV neuropathogenesis, we developed a model using human dorsal root ganglia (DRG xenografts in immunodeficient (SCID mice. The SCID DRG model provides an opportunity to examine characteristics of VZV infection that occur in the context of the specialized architecture of DRG, in which nerve cell bodies are ensheathed by satellite glial cells (SGC which support neuronal homeostasis. We hypothesized that VZV exhibits neuron-subtype specific tropism and that VZV tropism for SGC contributes to VZV-related ganglionopathy. Based on quantitative analyses of viral and cell protein expression in DRG tissue sections, we demonstrated that, whereas DRG neurons had an immature neuronal phenotype prior to implantation, subtype heterogeneity was observed within 20 weeks and SGC retained the capacity to maintain neuronal homeostasis longterm. Profiling VZV protein expression in DRG neurons showed that VZV enters peripherin+ nociceptive and RT97+ mechanoreceptive neurons by both axonal transport and contiguous spread from SGC, but replication in RT97+ neurons is blocked. Restriction occurs even when the SGC surrounding the neuronal cell body were infected and after entry and ORF61 expression, but before IE62 or IE63 protein expression. Notably, although contiguous VZV spread with loss of SGC support would be predicted to affect survival of both nociceptive and mechanoreceptive neurons, RT97+ neurons showed selective loss relative to peripherin+ neurons at later times in DRG infection. Profiling cell factors that were upregulated in VZV-infected DRG indicated that VZV infection induced marked pro-inflammatory responses, as well as proteins of the interferon pathway and neuroprotective responses. These neuropathologic changes

  3. Reduction of Cav1.3 channels in dorsal hippocampus impairs the development of dentate gyrus newborn neurons and hippocampal-dependent memory tasks.

    Directory of Open Access Journals (Sweden)

    Su-Hyun Kim

    Full Text Available Cav1.3 has been suggested to mediate hippocampal neurogenesis of adult mice and contribute to hippocampal-dependent learning and memory processes. However, the mechanism of Cav1.3 contribution in these processes is unclear. Here, roles of Cav1.3 of mouse dorsal hippocampus during newborn cell development were examined. We find that knock-out (KO of Cav1.3 resulted in the reduction of survival of newborn neurons at 28 days old after mitosis. The retroviral eGFP expression showed that both dendritic complexity and the number and length of mossy fiber bouton (MFB filopodia of newborn neurons at ≥ 14 days old were significantly reduced in KO mice. Both contextual fear conditioning (CFC and object-location recognition tasks were impaired in recent (1 day memory test while passive avoidance task was impaired only in remote (≥ 20 days memory in KO mice. Results using adeno-associated virus (AAV-mediated Cav1.3 knock-down (KD or retrovirus-mediated KD in dorsal hippocampal DG area showed that the recent memory of CFC was impaired in both KD mice but the remote memory was impaired only in AAV KD mice, suggesting that Cav1.3 of mature neurons play important roles in both recent and remote CFC memory while Cav1.3 in newborn neurons is selectively involved in the recent CFC memory process. Meanwhile, AAV KD of Cav1.3 in ventral hippocampal area has no effect on the recent CFC memory. In conclusion, the results suggest that Cav1.3 in newborn neurons of dorsal hippocampus is involved in the survival of newborn neurons while mediating developments of dendritic and axonal processes of newborn cells and plays a role in the memory process differentially depending on the stage of maturation and the type of learning task.

  4. 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.

  5. 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.

  6. The planarian TCF/LEF factor Smed-tcf1 is required for the regeneration of dorsal-lateral neuronal subtypes.

    Science.gov (United States)

    Brown, David D R; Molinaro, Alyssa M; Pearson, Bret J

    2018-01-15

    The adult brain of the planarian Schmidtea mediterranea (a freshwater flatworm) is a dynamic structure with constant cell turnover as well as the ability to completely regenerate de novo. Despite this, function and pattern is achieved in a reproducible manner from individual to individual in terms of the correct spatial and temporal production of specific neuronal subtypes. Although several signaling molecules have been found to be key to scaling and cell turnover, the mechanisms by which specific neural subtypes are specified remain largely unknown. Here we performed a 6 day RNAseq time course on planarians that were regenerating either 0, 1, or 2 heads in order to identify novel regulators of brain regeneration. Focusing on transcription factors, we identified a TCF/LEF factor, Smed-tcf1, which was required to correctly pattern the dorsal-lateral cell types of the regenerating brain. The most severely affected neurons in Smed-tcf1(RNAi) animals were the dorsal GABAergic neurons, which failed to regenerate, leading to an inability of the animals to phototaxis away from light. Together, Smed-tcf1 is a critical regulator, required to pattern the dorsal-lateral region of the regenerating planarian brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Up-regulation of p55 TNF alpha-receptor in dorsal root ganglia neurons following lumbar facet joint injury in rats.

    Science.gov (United States)

    Sakuma, Yoshihiro; Ohtori, Seiji; Miyagi, Masayuki; Ishikawa, Tetsu; Inoue, Gen; Doya, Hideo; Koshi, Takana; Ito, Toshinori; Yamashita, Masaomi; Yamauchi, Kazuyo; Suzuki, Munetaka; Moriya, Hideshige; Takahashi, Kazuhisa

    2007-08-01

    The rat L5/6 facet joint is multisegmentally innervated from the L1 to L6 dorsal root ganglia (DRG). Tumor necrosis factor (TNF) is a known mediator of inflammation. It has been reported that satellite cells are activated, produce TNF and surround DRG neurons innervating L5/6 facet joints after facet injury. In the current study, changes in TNF receptor (p55) expression in DRG neurons innervating the L5/6 facet joint following facet joint injury were investigated in rats using a retrograde neurotransport method followed by immunohistochemistry. Twenty rats were used for this study. Two crystals of Fluorogold (FG; neurotracer) were applied into the L5/6 facet joint. Seven days after surgery, the dorsal portion of the capsule was cut in the injured group (injured group n = 10). No injury was performed in the non-injured group (n = 10). Fourteen days after the first application of FG, bilateral DRGs from T13 to L6 levels were resected and sectioned. They were subsequently processed for p55 immunohistochemistry. The number of FG labeled neurons and number of FG labeled p55-immunoreactive (IR) neurons were counted. FG labeled DRG neurons innervating the L5/6 facet joint were distributed from ipsilateral L1 to L6 levels. Of FG labeled neurons, the ratio of DRG neurons immunoreactive for p55 in the injured group (50%) was significantly higher than that in the non-injured group (13%). The ratio of p55-IR neurons of FG labeled DRG neurons was significantly higher in total L1 and L2 DRGs than that in total L3, 4, 5 and 6 DRGs in the injured group (L1 and 2 DRG, 67%; L3, 4, 5 and 6 DRG, 37%, percentages of the total number of p55-IR neurons at L1 and L2 level or L3-6 level/the total number of FG-labeled neurons at L1 and L2 level or L3-6 level). These data suggest that up-regulation of p55 in DRG neurons may be involved in the sensory transmission from facet joint injury. Regulation of p55 in DRG neurons innervating the facet joint was different between upper DRG innervated

  8. Comparative study of the distribution of the alpha-subunits of voltage-gated sodium channels in normal and axotomized rat dorsal root ganglion neurons.

    Science.gov (United States)

    Fukuoka, Tetsuo; Kobayashi, Kimiko; Yamanaka, Hiroki; Obata, Koichi; Dai, Yi; Noguchi, Koichi

    2008-09-10

    We compared the distribution of the alpha-subunit mRNAs of voltage-gated sodium channels Nav1.1-1.3 and Nav1.6-1.9 and a related channel, Nax, in histochemically identified neuronal subpopulations of the rat dorsal root ganglia (DRG). In the naïve DRG, the expression of Nav1.1 and Nav1.6 was restricted to A-fiber neurons, and they were preferentially expressed by TrkC neurons, suggesting that proprioceptive neurons possess these channels. Nav1.7, -1.8, and -1.9 mRNAs were more abundant in C-fiber neurons compared with A-fiber ones. Nax was evenly expressed in both populations. Although Nav1.8 and -1.9 were preferentially expressed by TrkA neurons, other alpha-subunits were expressed independently of TrkA expression. Actually, all IB4(+) neurons expressed both Nav1.8 and -1.9, and relatively limited subpopulations of IB4(+) neurons (3% and 12%, respectively) expressed Nav1.1 and/or Nav1.6. These findings provide useful information in interpreting the electrophysiological characteristics of some neuronal subpopulations of naïve DRG. After L5 spinal nerve ligation, Nav1.3 mRNA was up-regulated mainly in A-fiber neurons in the ipsilateral L5 DRG. Although previous studies demonstrated that nerve growth factor (NGF) and glial cell-derived neurotrophic factor (GDNF) reversed this up-regulation, the Nav1.3 induction was independent of either TrkA or GFRalpha1 expression, suggesting that the induction of Nav1.3 may be one of the common responses of axotomized DRG neurons without a direct relationship to NGF/GDNF supply. (c) 2008 Wiley-Liss, Inc.

  9. The inhibition of the dorsal paragigantocellular reticular nucleus induces waking and the activation of all adrenergic and noradrenergic neurons: a combined pharmacological and functional neuroanatomical study.

    Science.gov (United States)

    Clément, Olivier; Valencia Garcia, Sara; Libourel, Paul-Antoine; Arthaud, Sébastien; Fort, Patrice; Luppi, Pierre-Hervé

    2014-01-01

    GABAergic neurons specifically active during paradoxical sleep (PS) localized in the dorsal paragigantocellular reticular nucleus (DPGi) are known to be responsible for the cessation of activity of the noradrenergic neurons of the locus coeruleus during PS. In the present study, we therefore sought to determine the role of the DPGi in PS onset and maintenance and in the inhibition of the LC noradrenergic neurons during this state. The effect of the inactivation of DPGi neurons on the sleep-waking cycle was examined in rats by microinjection of muscimol, a GABAA agonist, or clonidine, an alpha-2 adrenergic receptor agonist. Combining immunostaining of the different populations of wake-inducing neurons with that of c-FOS, we then determined whether muscimol inhibition of the DPGi specifically induces the activation of the noradrenergic neurons of the LC. Slow wave sleep and PS were abolished during 3 and 5 h after muscimol injection in the DPGi, respectively. The application of clonidine in the DPGi specifically induced a significant decrease in PS quantities and delayed PS appearance compared to NaCl. We further surprisingly found out that more than 75% of the noradrenergic and adrenergic neurons of all adrenergic and noradrenergic cell groups are activated after muscimol treatment in contrast to the other wake active systems significantly less activated. These results suggest that, in addition to its already know inhibition of LC noradrenergic neurons during PS, the DPGi might inhibit the activity of noradrenergic and adrenergic neurons from all groups during PS, but also to a minor extent during SWS and waking.

  10. The inhibition of the dorsal paragigantocellular reticular nucleus induces waking and the activation of all adrenergic and noradrenergic neurons: a combined pharmacological and functional neuroanatomical study.

    Directory of Open Access Journals (Sweden)

    Olivier Clément

    Full Text Available GABAergic neurons specifically active during paradoxical sleep (PS localized in the dorsal paragigantocellular reticular nucleus (DPGi are known to be responsible for the cessation of activity of the noradrenergic neurons of the locus coeruleus during PS. In the present study, we therefore sought to determine the role of the DPGi in PS onset and maintenance and in the inhibition of the LC noradrenergic neurons during this state. The effect of the inactivation of DPGi neurons on the sleep-waking cycle was examined in rats by microinjection of muscimol, a GABAA agonist, or clonidine, an alpha-2 adrenergic receptor agonist. Combining immunostaining of the different populations of wake-inducing neurons with that of c-FOS, we then determined whether muscimol inhibition of the DPGi specifically induces the activation of the noradrenergic neurons of the LC. Slow wave sleep and PS were abolished during 3 and 5 h after muscimol injection in the DPGi, respectively. The application of clonidine in the DPGi specifically induced a significant decrease in PS quantities and delayed PS appearance compared to NaCl. We further surprisingly found out that more than 75% of the noradrenergic and adrenergic neurons of all adrenergic and noradrenergic cell groups are activated after muscimol treatment in contrast to the other wake active systems significantly less activated. These results suggest that, in addition to its already know inhibition of LC noradrenergic neurons during PS, the DPGi might inhibit the activity of noradrenergic and adrenergic neurons from all groups during PS, but also to a minor extent during SWS and waking.

  11. The critical period for peripheral specification of dorsal root ganglion neurons is related to the period of sensory neurogenesis

    International Nuclear Information System (INIS)

    Smith, C.L.

    1990-01-01

    Thoracic sensory neurons in bullfrog tadpoles can be induced to form connections typical of brachial sensory neurons by transplanting thoracic ganglia to the branchial level at stages when some thoracic sensory neurons already have formed connections. In order to find out how many postmitotic sensory neurons survive transplantation, [ 3 H]thymidine was administered to tadpoles in which thoracic ganglia were transplanted to the brachial level unilaterally at stages VII to IX. Between 16 and 37% of the neurons in transplanted ganglia were unlabeled, as compared to 46 to 60% in unoperated ganglia. Transplanted ganglia contained fewer unlabeled neurons than corresponding unoperated ganglia, indicating that transplantation caused degeneration of postmitotic neurons. Therefore, a large fraction of the neurons that formed connections typical of brachial sensory neurons probably differentiated while they were at the brachial level

  12. 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.

  13. Distribution of α-synuclein in the spinal cord and dorsal root ganglia in an autopsy cohort of elderly persons.

    Science.gov (United States)

    Sumikura, Hiroyuki; Takao, Masaki; Hatsuta, Hiroyuki; Ito, Shinji; Nakano, Yuta; Uchino, Akiko; Nogami, Akane; Saito, Yuko; Mochizuki, Hideki; Murayama, Shigeo

    2015-09-15

    Lewy body-related α-synucleinopathy (LBAS, the abnormal accumulation of pathologic α-synuclein) is found in the central and peripheral nervous systems, including the spinal cord, dorsal root ganglia, and sympathetic ganglia, of Parkinson's disease patients. However, few studies have focused on the distribution of LBAS in the spinal cord, primary sensory neurons, and preganglionic sympathetic nerves. We analyzed 265 consecutive subjects with LBAS who underwent autopsy at a general geriatric hospital. LBAS in the spinal cord was significantly associated with that in the lower brainstem regions that are directly connected to the spinal cord (i.e., the medullary reticular formation and locus ceruleus), but it was not associated with the olfactory bulb-amygdala system, which is not directly connected to the spinal cord, suggesting that the lower brainstem is a key structure regarding the spread of LBAS to the spinal cord. In the primary sensory neurons, most subjects with LBAS in the dorsal root ganglia had LBAS in the dorsal root, and all subjects with LBAS in the dorsal root also had LBAS in the dorsal horn, suggesting that LBAS spreads retrogradely from the axonal terminals of the dorsal horn to the somata of the dorsal root ganglia via the dorsal root. In the preganglionic sympathetic nerves, the LBAS in the sympathetic ganglia preceded that in the nucleus of the intermediolateral column of the thoracic cord, suggesting that LBAS spreads retrogradely through the preganglionic sympathetic nerves. LBAS in the spinal cord was associated with the lower regions of the brainstem, but not with the olfactory bulb or amygdala. LBAS may spread centrifugally along the primary sensory neurons, whereas it may spread centripetally along the preganglionic sympathetic nerves.

  14. 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

  15. Anxiogenic drug administration and elevated plus-maze exposure in rats activate populations of relaxin-3 neurons in the nucleus incertus and serotonergic neurons in the dorsal raphe nucleus.

    Science.gov (United States)

    Lawther, A J; Clissold, M L; Ma, S; Kent, S; Lowry, C A; Gundlach, A L; Hale, M W

    2015-09-10

    Anxiety is a complex and adaptive emotional state controlled by a distributed and interconnected network of brain regions, and disruption of these networks is thought to give rise to the behavioral symptoms associated with anxiety disorders in humans. The dorsal raphe nucleus (DR), which contains the majority of forebrain-projecting serotonergic neurons, is implicated in the control of anxiety states and anxiety-related behavior via neuromodulatory effects on these networks. Relaxin-3 is the native neuropeptide ligand for the Gi/o-protein-coupled receptor, RXFP3, and is primarily expressed in the nucleus incertus (NI), a tegmental region immediately caudal to the DR. RXFP3 activation has been shown to modulate anxiety-related behavior in rodents, and RXFP3 mRNA is expressed in the DR. In this study, we examined the response of relaxin-3-containing neurons in the NI and serotonergic neurons in the DR following pharmacologically induced anxiety and exposure to an aversive environment. We administered the anxiogenic drug FG-7142 or vehicle to adult male Wistar rats and, 30 min later, exposed them to either the elevated plus-maze or home cage control conditions. Immunohistochemical detection of c-Fos was used to determine activation of serotonergic neurons in the DR and relaxin-3 neurons in the NI, measured 2h following drug injection. Analysis revealed that FG-7142 administration and exposure to the elevated plus-maze are both associated with an increase in c-Fos expression in relaxin-3-containing neurons in the NI and in serotonergic neurons in dorsal and ventrolateral regions of the DR. These data are consistent with the hypothesis that relaxin-3 systems in the NI and serotonin systems in the DR interact to form part of a network involved in the control of anxiety-related behavior. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. Effects of antagonists and heat on TRPM8 channel currents in dorsal root ganglion neuron activated by nociceptive cold stress and menthol.

    Science.gov (United States)

    Naziroğlu, Mustafa; Ozgül, Cemil

    2012-02-01

    Transient receptor potential ion channel melastatin subtype 8 (TRPM8) is activated by cold temperature and cooling agents, such as menthol and icilin. Compounds containing peppermint are reported to reduce symptoms of environmental cold stress such as cold allodynia in dorsal root ganglion (DRG) neuron; however, the underlying mechanisms of action are unclear. We tested the effects of physiological heat (37°C), anthralic acid (ACA and 0.025 mM), 2-aminoethyl diphenylborinate (2-APB and 0.05) on noxious cold (10°C) and menthol (0.1 mM)-induced TRPM8 cation channel currents in the DRG neurons of rats. DRG neurons were freshly isolated from rats. In whole-cell patch clamp experiments, TRPM8 currents were consistently induced by noxious cold or menthol. TRPM8 channels current densities of the neurons were higher in cold and menthol groups than in control. When the physiological heat is introduced by chamber TRPM8 channel currents were inhibited by the heat. Noxious cold-induced Ca(2+) gates were blocked by the ACA although menthol-induced TRPM8 currents were not blocked by ACA and 2-APB. In conclusion, the results suggested that activation of TRPM8 either by menthol or nociceptive cold can activate TRPM8 channels although we observed the protective role of heat, ACA and 2-APB through a TRPM8 channel in nociceptive cold-activated DRG neurons. Since cold allodynia is a common feature of neuropathic pain and diseases of sensory neuron, our findings are relevant to the etiology of neuropathology in DRG neurons.

  17. Neutrino horn

    CERN Multimedia

    1967-01-01

    View of the new neutrino horn installed in its blockhouse from the target end. Protons pass through the 2mm hole in the centre of the small fluorescent screen, hitting the target immediately behind it. The circular tubes carry pressurized cooling water.

  18. Hypocretin/Orexin Peptides Alter Spike Encoding by Serotonergic Dorsal Raphe Neurons through Two Distinct Mechanisms That Increase the Late Afterhyperpolarization.

    Science.gov (United States)

    Ishibashi, Masaru; Gumenchuk, Iryna; Miyazaki, Kenichi; Inoue, Takafumi; Ross, William N; Leonard, Christopher S

    2016-09-28

    Orexins (hypocretins) are neuropeptides that regulate multiple homeostatic processes, including reward and arousal, in part by exciting serotonergic dorsal raphe neurons, the major source of forebrain serotonin. Here, using mouse brain slices, we found that, instead of simply depolarizing these neurons, orexin-A altered the spike encoding process by increasing the postspike afterhyperpolarization (AHP) via two distinct mechanisms. This orexin-enhanced AHP (oeAHP) was mediated by both OX1 and OX2 receptors, required Ca(2+) influx, reversed near EK, and decayed with two components, the faster of which resulted from enhanced SK channel activation, whereas the slower component decayed like a slow AHP (sAHP), but was not blocked by UCL2077, an antagonist of sAHPs in some neurons. Intracellular phospholipase C inhibition (U73122) blocked the entire oeAHP, but neither component was sensitive to PKC inhibition or altered PKA signaling, unlike classical sAHPs. The enhanced SK current did not depend on IP3-mediated Ca(2+) release but resulted from A-current inhibition and the resultant spike broadening, which increased Ca(2+) influx and Ca(2+)-induced-Ca(2+) release, whereas the slower component was insensitive to these factors. Functionally, the oeAHP slowed and stabilized orexin-induced firing compared with firing produced by a virtual orexin conductance lacking the oeAHP. The oeAHP also reduced steady-state firing rate and firing fidelity in response to stimulation, without affecting the initial rate or fidelity. Collectively, these findings reveal a new orexin action in serotonergic raphe neurons and suggest that, when orexin is released during arousal and reward, it enhances the spike encoding of phasic over tonic inputs, such as those related to sensory, motor, and reward events. Orexin peptides are known to excite neurons via slow postsynaptic depolarizations. Here we elucidate a significant new orexin action that increases and prolongs the postspike

  19. 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.

  20. Long-term activation of group I metabotropic glutamate receptors increases functional TRPV1-expressing neurons in mouse dorsal root ganglia

    Directory of Open Access Journals (Sweden)

    Takayoshi eMasuoka

    2016-03-01

    Full Text Available Damaged tissues release glutamate and other chemical mediators for several hours. These chemical mediators contribute to modulation of pruritus and pain. Herein, we investigated the effects of long-term activation of excitatory glutamate receptors on functional expression of transient receptor potential vaniloid type 1 (TRPV1 in dorsal root ganglion (DRG neurons and then on thermal pain behavior. In order to detect the TRPV1-mediated responses in cultured DRG neurons, we monitored intracellular calcium responses to capsaicin, a TRPV1 agonist, with Fura-2. Long-term (4 h treatment with glutamate receptor agonists (glutamate, quisqualate or DHPG increased the proportion of neurons responding to capsaicin through activation of metabotropic glutamate receptor mGluR1, and only partially through the activation of mGluR5; engagement of these receptors was evident in neurons responding to allylisothiocyanate (AITC, a transient receptor potential ankyrin type 1 (TRPA1 agonist. Increase in the proportion was suppressed by phospholipase C, protein kinase C, mitogen/extracellular signal-regulated kinase, p38 mitogen-activated protein kinase or transcription inhibitors. Whole-cell recording was performed to record TRPV1-mediated membrane current; TRPV1 current density significantly increased in the AITC-sensitive neurons after the quisqualate treatment. To elucidate the physiological significance of this phenomenon, a hot plate test was performed. Intraplantar injection of quisqualate or DHPG induced heat hyperalgesia that lasted for 4 h post injection. This chronic hyperalgesia was attenuated by treatment with either mGluR1 or mGluR5 antagonists. These results suggest that long-term activation of mGluR1/5 by peripherally released glutamate may increase the number of neurons expressing functional TRPV1 in DRG, which may be strongly associated with chronic hyperalgesia.

  1. Effects of cocaine history on postsynaptic GABA receptors on dorsal raphe serotonin neurons in a stress-induced relapse model in rats.

    Science.gov (United States)

    Li, Chen; Kirby, Lynn G

    2016-01-01

    The serotonin (5-hydroxytryptamine, 5-HT) system plays an important role in stress-related psychiatric disorders and substance abuse. Stressors and stress hormones can inhibit the dorsal raphe nucleus (DRN)-5-HT system, which composes the majority of forebrain-projecting 5-HT. This inhibition is mediated via stimulation of GABA synaptic activity at DRN-5-HT neurons. Using swim stress-induced reinstatement of morphine conditioned place-preference, recent data from our laboratory indicate that morphine history sensitizes DRN-5-HT neurons to GABAergic inhibitory effects of stress. Moreover, GABAA receptor-mediated inhibition of the serotonergic DRN is required for this reinstatement. In our current experiment, we tested the hypothesis that GABAergic sensitization of DRN-5-HT neurons is a neuroadaptation elicited by multiple classes of abused drugs across multiple models of stress-induced relapse by applying a chemical stressor (yohimbine) to induce reinstatement of previously extinguished cocaine self-administration in Sprague-Dawley rats. Whole-cell patch-clamp recordings of GABA synaptic activity in DRN-5-HT neurons were conducted after the reinstatement. Behavioral data indicate that yohimbine triggered reinstatement of cocaine self-administration. Electrophysiology data indicate that 5-HT neurons in the cocaine group exposed to yohimbine had increased amplitude of inhibitory postsynaptic currents compared to yoked-saline controls exposed to yohimbine or unstressed animals in both drug groups. These data, together with previous findings, indicate that interaction between psychostimulant or opioid history and chemical or physical stressors may increase postsynaptic GABA receptor density and/or sensitivity in DRN-5-HT neurons. Such mechanisms may result in serotonergic hypofunction and consequent dysphoric mood states which confer vulnerability to stress-induced drug reinstatement. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  2. Bupropion-induced inhibition of α7 nicotinic acetylcholine receptors expressed in heterologous cells and neurons from dorsal raphe nucleus and hippocampus.

    Science.gov (United States)

    Vázquez-Gómez, Elizabeth; Arias, Hugo R; Feuerbach, Dominik; Miranda-Morales, Marcela; Mihailescu, Stefan; Targowska-Duda, Katarzyna M; Jozwiak, Krzysztof; García-Colunga, Jesús

    2014-10-05

    The pharmacological activity of bupropion was compared between α7 nicotinic acetylcholine receptors expressed in heterologous cells and hippocampal and dorsal raphe nucleus neurons. The inhibitory activity of bupropion was studied on GH3-α7 cells by Ca2+ influx, as well as on neurons from the dorsal raphe nucleus and interneurons from the stratum radiatum of the hippocampal CA1 region by using a whole-cell voltage-clamp technique. In addition, the interaction of bupropion with the α7 nicotinic acetylcholine receptor was determined by [3H]imipramine competition binding assays and molecular docking. The fast component of acetylcholine- and choline-induced currents from both brain regions was inhibited by methyllycaconitine, indicating the participation of α7-containing nicotinic acetylcholine receptors. Choline-induced currents in hippocampal interneurons were partially inhibited by 10 µM bupropion, a concentration that could be reached in the brain during clinical administration. Additionally, both agonist-induced currents were reversibly inhibited by bupropion at concentrations that coincide with its inhibitory potency (IC50=54 µM) and binding affinity (Ki=63 µM) for α7 nicotinic acetylcholine receptors from heterologous cells. The [3H]imipramine competition binding and molecular docking results support a luminal location for the bupropion binding site(s). This study may help to understand the mechanisms of actions of bupropion at neuronal and molecular levels related with its therapeutic actions on depression and for smoking cessation. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Focusing horn

    CERN Multimedia

    1980-01-01

    This was the first magnetic horn developed by Simon Van der Meer to collect antiprotons in the AD complex. It was used for the AA (antiproton accumulator). Making an antiproton beam took a lot of time and effort. Firstly, protons were accelerated to an energy of 26 GeV/c (protons at 26GeV/c, antiprotons at 3.6GeV/c) in the PS and ejected onto a metal target. From the spray of emerging particles, a magnetic horn picked out 3.6 GeV antiprotons for injection into the AA through a wide-aperture focusing quadrupole magnet. For a million protons hitting the target, just one antiproton was captured, 'cooled' and accumulated. It took 3 days to make a beam of 3 x 10^11 -, three hundred thousand million - antiprotons. The development of this technology was a key step to the functioning of CERN's Super Proton Synchrotron as a proton - antiproton collider.

  4. magnetic horn

    CERN Multimedia

    Neutrinos and antineutrinos are ideal for probing the weak force because it is effectively the only force they feel. How were they made? Protons fired into a metal target produce a tangle of secondary particles. A magnetic horn like this one, invented by Simon Van der Meer, selected pions and focused them into a sharp beam. Pions decay into muons and neutrinos or antineutrinos. The muons were stopped in a wall of 3000 tons of iron and 1000 tons of concrete, leaving the neutrinos or antineutrinos to reach the Gargamelle bubble chamber. A simple change of magnetic field direction on the horn flipped between focusing positively- or negatively-charged pion beams, and so between neutrinos and antineutrinos.

  5. 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.

  6. Effects of 14 days of spaceflight and nine days of recovery on cell body size and succinate dehydrogenase activity of rat dorsal root ganglion neurons

    Science.gov (United States)

    Ishihara, A.; Ohira, Y.; Roy, R. R.; Nagaoka, S.; Sekiguchi, C.; Hinds, W. E.; Edgerton, V. R.

    1997-01-01

    The cross-sectional areas and succinate dehydrogenase activities of L5 dorsal root ganglion neurons in rats were determined after 14 days of spaceflight and after nine days of recovery. The mean and distribution of the cross-sectional areas were similar to age-matched, ground-based controls for both the spaceflight and for the spaceflight plus recovery groups. The mean succinate dehydrogenase activity was significantly lower in spaceflight compared to aged-matched control rats, whereas the mean succinate dehydrogenase activity was similar in age-matched control and spaceflight plus recovery rats. The mean succinate dehydrogenase activity of neurons with cross-sectional areas between 1000 and 2000 microns2 was lower (between 7 and 10%) in both the spaceflight and the spaceflight plus recovery groups compared to the appropriate control groups. The reduction in the oxidative capacity of a subpopulation of sensory neurons having relatively large cross-sectional areas immediately following spaceflight and the sustained depression for nine days after returning to 1 g suggest that the 0 g environment induced significant alterations in proprioceptive function.

  7. Neuro-fuzzy decoding of sensory information from ensembles of simultaneously recorded dorsal root ganglion neurons for functional electrical stimulation applications.

    Science.gov (United States)

    Rigosa, J; Weber, D J; Prochazka, A; Stein, R B; Micera, S

    2011-08-01

    Functional electrical stimulation (FES) is used to improve motor function after injury to the central nervous system. Some FES systems use artificial sensors to switch between finite control states. To optimize FES control of the complex behavior of the musculo-skeletal system in activities of daily life, it is highly desirable to implement feedback control. In theory, sensory neural signals could provide the required control signals. Recent studies have demonstrated the feasibility of deriving limb-state estimates from the firing rates of primary afferent neurons recorded in dorsal root ganglia (DRG). These studies used multiple linear regression (MLR) methods to generate estimates of limb position and velocity based on a weighted sum of firing rates in an ensemble of simultaneously recorded DRG neurons. The aim of this study was to test whether the use of a neuro-fuzzy (NF) algorithm (the generalized dynamic fuzzy neural networks (GD-FNN)) could improve the performance, robustness and ability to generalize from training to test sets compared to the MLR technique. NF and MLR decoding methods were applied to ensemble DRG recordings obtained during passive and active limb movements in anesthetized and freely moving cats. The GD-FNN model provided more accurate estimates of limb state and generalized better to novel movement patterns. Future efforts will focus on implementing these neural recording and decoding methods in real time to provide closed-loop control of FES using the information extracted from sensory neurons.

  8. 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...

  9. How does early maternal separation and chronic stress in adult rats affect the immunoreactivity of serotonergic neurons within the dorsal raphe nucleus?

    Science.gov (United States)

    Pollano, Antonella; Trujillo, Verónica; Suárez, Marta M

    2018-01-01

    Vulnerability to emotional disorders like depression derives from interactions between early and late environments, including stressful conditions. The serotonin (5HT) system is strongly affected by stress and chronic unpredictable stress can alter the 5HT system. We evaluated the distribution of active serotonergic neurons in the dorsal raphe nucleus (DR) through immunohistochemistry in maternally separated and chronically stressed rats treated with an antidepressant, tianeptine, whose mechanism of action is still under review. Male Wistar rats were subjected to daily maternal separation (MS) for 4.5 h between postnatal days (PND) 1-21, or to animal facility rearing (AFR). Between (PND) days 50-74, rats were exposed to chronic unpredictable stress and were treated daily with tianeptine (10 mg/kg) or vehicle. We found an interaction between the effects of MS and chronic unpredictable stress on Fos-5HT immunoreactive cells at mid-caudal level of the DR. MS-chronically stressed rats showed an increase of Fos-5HT immunoreactive cells compared with AFR-chronically stressed rats. The ventrolateral (DRL/VLPAG) and dorsal (DRD) subdivisions of the DR were significantly more active than the ventral part (DRV). At the rostral level of the DR, tianeptine decreased the number of Fos-5HT cells in DR in the AFR groups, both unstressed and stressed. Overall, our results support the idea of a match in phenotype exhibited when the early and the adult environment correspond.

  10. Ultrastructural Visualization of Individual Tegument Protein Dissociation during Entry of Herpes Simplex Virus 1 into Human and Rat Dorsal Root Ganglion Neurons

    Science.gov (United States)

    Aggarwal, Anupriya; Boadle, Ross A.; Kelly, Barbara J.; Diefenbach, Russell J.; Alam, Waafiqa; Cunningham, Anthony L.

    2012-01-01

    Herpes simplex virus 1 (HSV-1) enters neurons primarily by fusion of the viral envelope with the host cell plasma membrane, leading to the release of the capsid into the cytosol. The capsid travels via microtubule-mediated retrograde transport to the nuclear membrane, where the viral DNA is released for replication in the nucleus. In the present study, the composition and kinetics of incoming HSV-1 capsids during entry and retrograde transport in axons of human fetal and dissociated rat dorsal root ganglia (DRG) neurons were examined by wide-field deconvolution microscopy and transmission immunoelectron microscopy (TIEM). We show that HSV-1 tegument proteins, including VP16, VP22, most pUL37, and some pUL36, dissociated from the incoming virions. The inner tegument proteins, including pUL36 and some pUL37, remained associated with the capsid during virus entry and transit to the nucleus in the neuronal cell body. By TIEM, a progressive loss of tegument proteins, including VP16, VP22, most pUL37, and some pUL36, was observed, with most of the tegument dissociating at the plasma membrane of the axons and the neuronal cell body. Further dissociation occurred within the axons and the cytosol as the capsids moved to the nucleus, resulting in the release of free tegument proteins, especially VP16, VP22, pUL37, and some pUL36, into the cytosol. This study elucidates ultrastructurally the composition of HSV-1 capsids that encounter the microtubules in the core of human axons and the complement of free tegument proteins released into the cytosol during virus entry. PMID:22457528

  11. NGF-induced hyperexcitability causes spontaneous fluctuations of intracellular Ca(2+) in rat nociceptive dorsal root ganglion neurons

    Czech Academy of Sciences Publication Activity Database

    Ozaki, Y.; Kitamura, N.; Tsutsumi, A.; Dayanithi, Govindan; Shibuya, I.

    2009-01-01

    Roč. 45, č. 3 (2009), s. 209-215 ISSN 0143-4160 Institutional research plan: CEZ:AV0Z50390512 Keywords : sensory neuron * capsaicin * TRPV1 Subject RIV: FH - Neurology Impact factor: 4.288, year: 2009

  12. P2X7 receptors in satellite glial cells mediate high functional expression of P2X3 receptors in immature dorsal root ganglion neurons

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    Chen Yong

    2012-02-01

    Full Text Available Abstract Background The purinergic P2X3 receptor (P2X3R expressed in the dorsal root ganglion (DRG sensory neuron and the P2X7 receptor (P2X7R expressed in the surrounding satellite glial cell (SGC are two major receptors participating in neuron-SGC communication in adult DRGs. Activation of P2X7Rs was found to tonically reduce the expression of P2X3Rs in DRGs, thus inhibiting the abnormal pain behaviors in adult rats. P2X receptors are also actively involved in sensory signaling in developing rodents. However, very little is known about the developmental change of P2X7Rs in DRGs and the interaction between P2X7Rs and P2X3Rs in those animals. We therefore examined the expression of P2X3Rs and P2X7Rs in postnatal rats and determined if P2X7R-P2X3R control exists in developing rats. Findings We immunostained DRGs of immature rats and found that P2X3Rs were expressed only in neurons and P2X7Rs were expressed only in SGCs. Western blot analyses indicated that P2X3R expression decreased while P2X7R expression increased with the age of rats. Electrophysiological studies showed that the number of DRG neurons responding to the stimulation of the P2XR agonist, α,β-meATP, was higher and the amplitudes of α,β-meATP-induced depolarizations were larger in immature DRG neurons. As a result, P2X3R-mediated flinching responses were much more pronounced in immature rats than those found in adult rats. When we reduced P2X7R expression with P2X7R-siRNA in postnatal and adult rats, P2X3R-mediated flinch responses were greatly enhanced in both rat populations. Conclusions These results show that the P2X7R expression increases as rats age. In addition, P2X7Rs in SGCs exert inhibitory control on the P2X3R expression and function in sensory neurons of immature rats, just as observed in adult rats. Regulation of P2X7R expression is likely an effective way to control P2X3R activity and manage pain relief in infants.

  13. c-Fos and pERK, which is a better marker for neuronal activation and central sensitization after noxious stimulation and tissue injury?

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    Gao, Yong-Jing; Ji, Ru-Rong

    2009-01-01

    c-Fos, the protein of the protooncogene c-fos, has been extensively used as a marker for the activation of nociceptive neurons in the spinal cord for more than twenty years since Hunt et al. first reported that peripheral noxious stimulation to a hind paw of rats leads to a marked induction of c-Fos in superficial and deep dorsal horn neurons in 1987. In 1999, Ji et al. reported that phosphorylated extracellular signal-regulated kinase (pERK) is specifically induced by noxious stimulation in superficial dorsal horn neurons. Accumulating evidence indicates that pERK induction or ERK activation in dorsal horn neurons is essential for the development of central sensitization, increased sensitivity of dorsal horn neurons that is responsible for the generation of persistent pain. Further, molecular mechanisms underlying ERK-mediated central sensitization have been revealed. In contrast, direct evidence for c-Fos-mediated central sensitization is not sufficient. After a noxious stimulus (e.g., capsaicin injection) or tissue injury, c-Fos begins to be induced after 30-60 minutes, whereas pERK can be induced within a minute, which can correlate well with the development of pain hypersensitivity. While c-Fos is often induced in the nuclei of neurons, pERK can be induced in different subcellular structures of neurons such as nuclei, cytoplasma, axons, and dendrites. pERK can even be induced in spinal cord microglia and astrocytes after nerve injury. In summary, both c-Fos and pERK can be used as markers for neuronal activation following noxious stimulation and tissue injury, but pERK is much more dynamic and appears to be a better marker for central sensitization.

  14. Effects of (−-Gallocatechin-3-Gallate on Tetrodotoxin-Resistant Voltage-Gated Sodium Channels in Rat Dorsal Root Ganglion Neurons

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    Jian-Min Jiang

    2013-05-01

    Full Text Available The (−-gallocatechin-3-gallate (GCG concentration in some tea beverages can account for as much as 50% of the total catechins. It has been shown that catechins have analgesic properties. Voltage-gated sodium channels (Nav mediate neuronal action potentials. Tetrodotoxin inhibits all Nav isoforms, but Nav1.8 and Nav1.9 are relatively tetrodotoxin-resistant compared to other isoforms and functionally linked to nociception. In this study, the effects of GCG on tetrodotoxin-resistant Na+ currents were investigated in rat primary cultures of dorsal root ganglion neurons via the whole-cell patch-clamp technique. We found that 1 μM GCG reduced the amplitudes of peak current density of tetrodotoxin-resistant Na+ currents significantly. Furthermore, the inhibition was accompanied by a depolarizing shift of the activation voltage and a hyperpolarizing shift of steady-state inactivation voltage. The percentage block of GCG (1 μM on tetrodotoxin-resistant Na+ current was 45.1% ± 1.1% in 10 min. In addition, GCG did not produce frequency-dependent block of tetrodotoxin-resistant Na+ currents at stimulation frequencies of 1 Hz, 2 Hz and 5 Hz. On the basis of these findings, we propose that GCG may be a potential analgesic agent.

  15. Effects of curcumin on TTX-R sodium currents of dorsal root ganglion neurons in type 2 diabetic rats with diabetic neuropathic pain.

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    Meng, Bo; Shen, Lu-Lu; Shi, Xiao-Ting; Gong, Yong-Sheng; Fan, Xiao-Fang; Li, Jun; Cao, Hong

    2015-09-25

    Type 2 diabetic mellitus (T2DM) has reached pandemic status and shows no signs of abatement. Diabetic neuropathic pain (DNP) is generally considered to be one of the most common complications of T2DM, which is also recognized as one of the most difficult types of pain to treat. As one kind of peripheral neuropathic pain, DNP manifests typical chronic neuralgia symptoms, including hyperalgesia, allodynia, autotomy, and so on. The injured dorsal root ganglion (DRG) is considered as the first stage of the sensory pathway impairment, whose neurons display increased frequency of action potential generation and increased spontaneous activities. These are mainly due to the changed properties of voltage-gated sodium channels (VGSCs) and the increased sodium currents, especially TTX-R sodium currents. Curcumin, one of the most important phytochemicals from turmeric, has been demonstrated to effectively prevent and/or ameliorate diabetic mellitus and its complications including DNP. The present study demonstrates that the TTX-R sodium currents of small-sized DRG neurons isolated from DNP rats are significantly increased. Such abnormality can be efficaciously ameliorated by curcumin. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. Origins, actions and dynamic expression patterns of the neuropeptide VGF in rat peripheral and central sensory neurones following peripheral nerve injury

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    Costigan Michael

    2008-12-01

    Full Text Available Abstract Background The role of the neurotrophin regulated polypeptide, VGF, has been investigated in a rat spared injury model of neuropathic pain. This peptide has been shown to be associated with synaptic strengthening and learning in the hippocampus and while it is known that VGFmRNA is upregulated in dorsal root ganglia following peripheral nerve injury, the role of this VGF peptide in neuropathic pain has yet to be investigated. Results Prolonged upregulation of VGF mRNA and protein was observed in injured dorsal root ganglion neurons, central terminals and their target dorsal horn neurons. Intrathecal application of TLQP-62, the C-terminal active portion of VGF (5–50 nmol to naïve rats caused a long-lasting mechanical and cold behavioral allodynia. Direct actions of 50 nM TLQP-62 upon dorsal horn neuron excitability was demonstrated in whole cell patch recordings in spinal cord slices and in receptive field analysis in intact, anesthetized rats where significant actions of VGF were upon spontaneous activity and cold evoked responses. Conclusion VGF expression is therefore highly modulated in nociceptive pathways following peripheral nerve injury and can cause dorsal horn cell excitation and behavioral hypersensitivity in naïve animals. Together the results point to a novel and powerful role for VGF in neuropathic pain.

  17. cAMP-dependent insulin modulation of synaptic inhibition in neurons of the dorsal motor nucleus of the vagus is altered in diabetic mice

    Science.gov (United States)

    Blake, Camille B.

    2014-01-01

    Pathologies in which insulin is dysregulated, including diabetes, can disrupt central vagal circuitry, leading to gastrointestinal and other autonomic dysfunction. Insulin affects whole body metabolism through central mechanisms and is transported into the brain stem dorsal motor nucleus of the vagus (DMV) and nucleus tractus solitarius (NTS), which mediate parasympathetic visceral regulation. The NTS receives viscerosensory vagal input and projects heavily to the DMV, which supplies parasympathetic vagal motor output. Normally, insulin inhibits synaptic excitation of DMV neurons, with no effect on synaptic inhibition. Modulation of synaptic inhibition in DMV, however, is often sensitive to cAMP-dependent mechanisms. We hypothesized that an effect of insulin on GABAergic synaptic transmission may be uncovered by elevating resting cAMP levels in GABAergic terminals. We used whole cell patch-clamp recordings in brain stem slices from control and diabetic mice to identify insulin effects on inhibitory neurotransmission in the DMV in the presence of forskolin to elevate cAMP levels. In the presence of forskolin, insulin decreased the frequency of inhibitory postsynaptic currents (IPSCs) and the paired-pulse ratio of evoked IPSCs in DMV neurons from control mice. This effect was blocked by brefeldin-A, a Golgi-disrupting agent, or indinavir, a GLUT4 blocker, indicating that protein trafficking and glucose transport were involved. In streptozotocin-treated, diabetic mice, insulin did not affect IPSCs in DMV neurons in the presence of forskolin. Results suggest an impairment of cAMP-induced insulin effects on GABA release in the DMV, which likely involves disrupted protein trafficking in diabetic mice. These findings provide insight into mechanisms underlying vagal dysregulation associated with diabetes. PMID:24990858

  18. GABA(B) receptor modulation of serotonin neurons in the dorsal raphé nucleus and escalation of aggression in mice.

    Science.gov (United States)

    Takahashi, Aki; Shimamoto, Akiko; Boyson, Christopher O; DeBold, Joseph F; Miczek, Klaus A

    2010-09-01

    The serotonin (5-HT) system in the brain has been studied more than any other neurotransmitter for its role in the neurobiological basis of aggression. However, which mechanisms modulate the 5-HT system to promote escalated aggression is not clear. We here explore the role of GABAergic modulation in the raphé nuclei, from which most 5-HT in the forebrain originates, on escalated aggression in male mice. Pharmacological activation of GABA(B), but not GABA(A), receptors in the dorsal raphé nucleus (DRN) escalated aggressive behaviors. In contrast, GABA agonists did not escalate aggressive behaviors after microinjection into the median raphé nucleus. The aggression-heightening effect of the GABA(B) agonist baclofen depended on the activation of 5-HT neurons in the DRN because it was blocked by coadministration of the 5-HT(1A) agonist 8-OH-DPAT [((+/-)-8-hydroxy-2-(di-n-propylamino)tetralin) hydrobromide] (DPAT), which acts on autoreceptors and inhibits 5-HT neural activity. In vivo microdialysis showed that GABA(B) activation in the DRN increased extracellular 5-HT level in the medial prefrontal cortex. This may be attributable to an indirect action via presynaptic GABA(B) receptors. The presynaptic GABA(B) receptors suppress Ca(2+) channel activity and inhibit neurotransmission, and the coadministration of N-type Ca(2+) channel blocker facilitated the effect of baclofen. These findings suggest that the indirect disinhibition of 5-HT neuron activity by presynaptic GABA(B) receptors on non-5-HT neurons in the DRN is one of the neurobiological mechanisms of escalated aggression.

  19. Differential effects of temperature on acid-activated currents mediated by TRPV1 and ASIC channels in rat dorsal root ganglion neurons.

    Science.gov (United States)

    Neelands, Torben R; Zhang, Xu-Feng; McDonald, Heath; Puttfarcken, Pamela

    2010-05-06

    Elevated temperature and decreased extracellular pH are hallmarks of inflammatory pain states. Dorsal root ganglia (DRG) neurons are integral in transferring painful stimuli from the periphery to central sites. This study investigated the effect of elevated temperatures on the response of DRG neurons to acute application of acidic solutions. At room temperature (22 degrees C), in response to pH 5.5, there were a variety of kinetic responses consistent with differential expression of TRPV1 and ASIC channels. Increasing the temperature resulted in a significant increase in the peak and total current mediated by TRPV1 in response to an acidic solution. In contrast, the amplitude of a fast activating, rapidly inactivating ASIC1-like current was not affected by increasing the temperature but did result in an increased rate of desensitization that reduced the total current level. This effect on the rate of desensitization was temperature-dependent and could be reversed by returning to 22 degrees C. Likewise, cells exhibiting slowly inactivating ASIC2-like responses also had temperature-dependent increase in the rate of desensitization. The ASIC2-like responses and the TRPV1 responses tended to decrease in amplitude with repetitive application of pH 5.5 even at 22 degrees C. The rate of desensitization of ASIC-like currents activated by less acidic solutions (pH 6.8) was also increased in a temperature-dependent manner. Finally, acidic pH reduced threshold to trigger action potentials, however, the pattern of action potential firing was shaped by the distribution of ASIC and TRPV1 channels. These results indicate that the ambient temperature at which acidosis occurs has a profound effect on the contribution of ASIC and TRPV1 channels, therefore, altering the neuronal excitability. Copyright 2010 Elsevier B.V. All rights reserved.

  20. Anterior Horn Cell Diseases

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    Merve Firinciogullari

    2016-09-01

    Full Text Available The anterior horn cells control all voluntary movement. Motor activity, respiratory, speech, and swallowing functions are dependent upon signals from the anterior horn cells. Diseases that damage the anterior horn cells, therefore, have a profound impact. Symptoms of anterior horn cell loss (weakness, falling, choking lead patients to seek medical attention. In this article, anterior horn diseases were reviewed, diagnostic criteria and management were discussed in detail. [Archives Medical Review Journal 2016; 25(3.000: 269-303

  1. The Venom of the Spider Selenocosmia Jiafu Contains Various Neurotoxins Acting on Voltage-Gated Ion Channels in Rat Dorsal Root Ganglion Neurons

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    Zhaotun Hu

    2014-03-01

    Full Text Available Selenocosmia jiafu is a medium-sized theraphosid spider and an attractive source of venom, because it can be bred in captivity and it produces large amounts of venom. We performed reversed-phase high-performance liquid chromatography (RP-HPLC and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS analyses and showed that S. jiafu venom contains hundreds of peptides with a predominant mass of 3000–4500 Da. Patch clamp analyses indicated that the venom could inhibit voltage-gated Na+, K+ and Ca2+ channels in rat dorsal root ganglion (DRG neurons. The venom exhibited inhibitory effects on tetrodotoxin-resistant (TTX-R Na+ currents and T-type Ca2+ currents, suggesting the presence of antagonists to both channel types and providing a valuable tool for the investigation of these channels and for drug development. Intra-abdominal injection of the venom had severe toxic effects on cockroaches and caused death at higher concentrations. The LD50 was 84.24 μg/g of body weight in the cockroach. However, no visible symptoms or behavioral changes were detected after intraperitoneal injection of the venom into mice even at doses up to 10 mg/kg body weight. Our results provide a basis for further case-by-case investigations of peptide toxins from this venom.

  2. p38 MAPK Mediates Glial P2X7R-Neuronal P2Y1R Inhibitory Control of P2X3R Expression in Dorsal Root Ganglion Neurons.

    Science.gov (United States)

    Chen, Yong; Li, Guangwen; Huang, Li-Yen Mae

    2015-01-01

    We have previously shown that endogenously active purinergic P2X7 receptors (P2X7Rs) in satellite glial cells of dorsal root ganglia (DRGs) stimulate ATP release. The ATP activates P2Y1Rs located in the enwrapped neuronal somata, resulting in down-regulation of P2X3Rs. This P2X7R-P2Y1-P2X3R inhibitory control significantly reduces P2X3R-mediated nociceptive responses. The underlying mechanism by which the activation of P2Y1Rs inhibits the expression of P2X3Rs remains unexplored. Examining the effect of the activation of p38 mitogen-activated protein kinase on the expression of P2X3Rs in DRGs, we found that the p38 activator, anisomycin (Anis), reduced the expression of P2X3Rs. Blocking the activity of SGCs by the glial Krebs cycle inhibitor, fluorocitrate, did not change the effect of Anis. These results suggest that neuronal p38 plays a major role in the inhibition of P2X3R expression. Western blotting analyses showed that inhibiting P2Y1Rs by MRS2179 (MRS) or blocking P2X7Rs by either oxATP or A740003 reduced pp38 and increased P2X3R expression in DRGs. These results are further supported by the immunohistochemical study showing that P2X7R and P2Y1R antagonists reduce the percentage of pp38-positive neurons. These observations suggest that activation of P2X7Rs and P2Y1Rs promotes p38 activity to exert inhibitory control on P2X3R expression. Since activation of p38 by Anis in the presence of either A740003 or MRS could overcome the block of P2X7R-P2Y1R inhibitory control, p38 in DRG neurons is downstream of P2Y1Rs. In addition, inhibition of p38 by SB202190 was found to prevent the P2X7R and P2Y1R block of P2X3R expression and increase P2X3R-mediated nociceptive flinch behaviors. p38 in DRG neurons downstream of P2Y1R is necessary and sufficient for the P2X7R-P2Y1R inhibitory control of P2X3R expression. © 2015 Chen et al.

  3. 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.

  4. Modified dorsal root entry zone lesioning for intractable pain relief in patients with root avulsion injury.

    Science.gov (United States)

    Takai, Keisuke; Taniguchi, Makoto

    2017-08-01

    OBJECTIVE Dorsal root entry zone (DREZ) lesioning has been the most effective surgical treatment for the relief of intractable pain due to root avulsion injury, but residual pain and a decrease in pain relief in the follow-up period have been reported in 23%-70% of patients. Based on pain topography in the most recent studies on neuropathic pain, the authors modified the conventional DREZ lesioning procedure to improve clinical outcomes. The presumed rationale for this procedure is to eliminate the spontaneous discharges of neurons in the superficial spinal dorsal horn as well as wide dynamic range neurons in the deep spinal dorsal horn. METHODS Ten patients with avulsion-related pain underwent surgery between 2011 and 2015. The surgical procedure was described and postoperative pain relief was assessed as follows: excellent (residual pain never exceeded 3 on the visual analog scale [VAS] without medication), good (residual pain never exceeded 5 on the VAS with medication), and poor (residual pain was greater than 5 with medication). Specific perioperative complications were assessed. RESULTS The aim of this surgical procedure was to destroy the deeper layers of the posterior horn of spinal gray matter, which was in contrast to the procedures of Nashold and Sindou, which were to destroy the superficial layers. All patients achieved excellent (n = 7, pain relief without medication) or good (n = 3, pain relief with medication) pain relief postoperatively, and the recurrence of pain was not reported in any patients (median 29 months after surgery, range 12-64 months). Nine patients (90%) achieved complete pain relief (a score of 0 or 1 on the VAS) with or without medication. No surgical site complications such as infection or CSF leakage were noted. No motor deficit was observed in any patient. A sensory deficit was observed in 2 patients and disappeared within 1 month in 1 patient. New pain at the adjacent level of DREZ lesioning was observed in 3 patients and

  5. Localization of SSeCKS in unmyelinated primary sensory neurons

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    Siegel Sandra M

    2008-03-01

    Full Text Available Abstract Background SSeCKS (Src SupprEssed C Kinase Substrate is a proposed protein kinase C substrate/A kinase anchoring protein (AKAP that has recently been characterized in the rat peripheral nervous system. It has been shown that approximately 40% of small primary sensory neurons contain SSeCKS-immunoreactivity in a population largely separate from substance P (95.2%, calcitonin gene related peptide (95.3%, or fluoride resistant acid phosphatase (55.0% labeled cells. In the spinal cord, it was found that SSeCKS-immunoreactive axon collaterals terminate in the dorsal third of lamina II outer in a region similar to that of unmyelinated C-, or small diameter myelinated Aδ-, fibers. However, the precise characterization of the anatomical profile of the primary sensory neurons containing SSeCKS remains to be determined. Here, immunohistochemical labeling at the light and ultrastructural level is used to clarify the myelination status of SSeCKS-containing sensory neuron axons and to further clarify the morphometric, and provide insight into the functional, classification of SSeCKS-IR sensory neurons. Methods Colocalization studies of SSeCKS with myelination markers, ultrastructural localization of SSeCKS labeling and ablation of largely unmyelinated sensory fibers by neonatal capsaicin administration were all used to establish whether SSeCKS containing sensory neurons represent a subpopulation of unmyelinated primary sensory C-fibers. Results Double labeling studies of SSeCKS with CNPase in the dorsal horn and Pzero in the periphery showed that SSeCKS immunoreactivity was observed predominantly in association with unmyelinated primary sensory fibers. At the ultrastructural level, SSeCKS immunoreactivity was most commonly associated with axonal membrane margins of unmyelinated fibers. In capsaicin treated rats, SSeCKS immunoreactivity was essentially obliterated in the dorsal horn while in dorsal root ganglia quantitative analysis revealed a 43

  6. Orai1 Plays a Crucial Role in Central Sensitization by Modulating Neuronal Excitability.

    Science.gov (United States)

    Dou, Yannong; Xia, Jingsheng; Gao, Ruby; Gao, Xinghua; Munoz, Frances M; Wei, Dongyu; Tian, Yuzhen; Barrett, James E; Ajit, Seena; Meucci, Olimpia; Putney, James W; Dai, Yue; Hu, Huijuan

    2018-01-24

    Pathological pain is a common and debilitating condition that is often poorly managed. Central sensitization is an important mechanism underlying pathological pain. However, candidate molecules involved in central sensitization remain unclear. Store-operated calcium channels (SOCs) mediate important calcium signals in nonexcitable and excitable cells. SOCs have been implicated in a wide variety of human pathophysiological conditions, including immunodeficiency, occlusive vascular diseases, and cancer. However, the role of SOCs in CNS disorders has been relatively unexplored. Orai1, a key component of SOCs, is expressed in the human and rodent spinal cord dorsal horn, but its functional significance in dorsal horn neurons is poorly understood. Here we sought to explore a potential role of Orai1 in the modulation of neuronal excitability and A-type potassium channels involved in pain plasticity. Using both male and female Orai1 knock-out mice, we found that activation of Orai1 increased neuronal excitability and reduced A-type potassium channels via the protein kinase C-extracellular signal-regulated protein kinase (PKC-ERK) pathway in dorsal horn neurons. Orai1 deficiency significantly decreased acute pain induced by noxious stimuli, nearly eliminated the second phase of formalin-induced nociceptive response, markedly attenuated carrageenan-induced ipsilateral pain hypersensitivity and abolished carrageenan-induced contralateral mechanical allodynia. Consistently, carrageenan-induced increase in neuronal excitability was abolished in the dorsal horn from Orai1 mutant mice. These findings uncover a novel signaling pathway involved in the pain process and central sensitization. Our study also reveals a novel link among Orai1, ERK, A-type potassium channels, and neuronal excitability. SIGNIFICANCE STATEMENT Orai1 is a key component of store-operated calcium channels (SOCs) in many cell types. It has been implicated in such pathological conditions as immunodeficiency

  7. The effects of neuroleptics on the GABA-induced Cl- current in rat dorsal root ganglion neurons: differences between some neuroleptics.

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    Yokota, Kenjiro; Tatebayashi, Hideharu; Matsuo, Tadashi; Shoge, Takashi; Motomura, Haruhiko; Matsuno, Toshiyuki; Fukuda, Akira; Tashiro, Nobutada

    2002-03-01

    1. Several neuroleptics inhibited the 3 microM gamma-aminobutyric acid induced-chloride current (GABA-current) on dissociated rat dorsal root ganglion neurons in whole-cell patch-clamp investigations. 2. The IC(50) for clozapine, zotepine, olanzapine, risperidone and chlorpromazine were 6.95, 18.26, 20.30, 106.01 and 114.56 microM, respectively. The values for the inhibitory effects of neuroleptics on the GABA (3 microM)-current, which were calculated by the fitting Hill's equations where the concentrations represent the mean therapeutic blood concentrations, were ranked clozapine>zotepine>chlorpromazine>olanzapine>risperidone. These inhibitory effects, weighted with the therapeutic concentrations of neuroleptics, were correlated with the clinical incidences of seizure during treatment with neuroleptics. 3. Clozapine reduced the picrotoxin-inhibiton, and may compete with a ligand of the t-butylbicyclophosphorothionate (TBPS) binding site. 4. Haloperidol and quetiapine did not affect the peak amplitude of the GABA (3 microM)-current. However, haloperidol reduced the clozapine-inhibition, and may antagonize ligand binding to TBPS binding site. 5. Neuroleptics including haloperidol and quetiapine enhanced the desensitization of the GABA (3 microM)-current. However, haloperidol and quetiapine at 100 microM inhibited the desensitization at the beginning of application. 6. Blonanserin (AD-5423) at 30 and 50 microM potentiated the GABA (3 microM)-current to 170.1+/-6.9 and 192.0+/-10.6% of the control current, respectively. Blonanserin shifted GABA concentration-response curve leftward. Blonanserin only partly negatively interacted with diazepam. The blonanserin-potentiation was not reversed by flumazenil. Blonanserin is not a benzodiazepine receptor agonist. 7. The various effects of neuroleptics on the GABA-current may be related to the clinical effects including modifying the seizure threshold.

  8. The effects of neuroleptics on the GABA-induced Cl− current in rat dorsal root ganglion neurons: differences between some neuroleptics

    Science.gov (United States)

    Yokota, Kenjiro; Tatebayashi, Hideharu; Matsuo, Tadashi; Shoge, Takashi; Motomura, Haruhiko; Matsuno, Toshiyuki; Fukuda, Akira; Tashiro, Nobutada

    2002-01-01

    Several neuroleptics inhibited the 3 μM γ-aminobutyric acid induced-chloride current (GABA-current) on dissociated rat dorsal root ganglion neurons in whole-cell patch-clamp investigations. The IC50 for clozapine, zotepine, olanzapine, risperidone and chlorpromazine were 6.95, 18.26, 20.30, 106.01 and 114.56 μM, respectively. The values for the inhibitory effects of neuroleptics on the GABA (3 μM)-current, which were calculated by the fitting Hill's equations where the concentrations represent the mean therapeutic blood concentrations, were ranked clozapine>zotepine>chlorpromazine>olanzapine>risperidone. These inhibitory effects, weighted with the therapeutic concentrations of neuroleptics, were correlated with the clinical incidences of seizure during treatment with neuroleptics. Clozapine reduced the picrotoxin-inhibiton, and may compete with a ligand of the t-butylbicyclophosphorothionate (TBPS) binding site. Haloperidol and quetiapine did not affect the peak amplitude of the GABA (3 μM)-current. However, haloperidol reduced the clozapine-inhibition, and may antagonize ligand binding to TBPS binding site. Neuroleptics including haloperidol and quetiapine enhanced the desensitization of the GABA (3 μM)-current. However, haloperidol and quetiapine at 100 μM inhibited the desensitization at the beginning of application. Blonanserin (AD-5423) at 30 and 50 μM potentiated the GABA (3 μM)-current to 170.1±6.9 and 192.0±10.6% of the control current, respectively. Blonanserin shifted GABA concentration-response curve leftward. Blonanserin only partly negatively interacted with diazepam. The blonanserin-potentiation was not reversed by flumazenil. Blonanserin is not a benzodiazepine receptor agonist. The various effects of neuroleptics on the GABA-current may be related to the clinical effects including modifying the seizure threshold. PMID:11906969

  9. Regulation of the Spontaneous Augmentation of NaV1.9 in Mouse Dorsal Root Ganglion Neurons: Effect of PKA and PKC Pathways

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    Nobukuni Ogata

    2010-03-01

    Full Text Available Sensory neurons in the dorsal root ganglion express two kinds of tetrodotoxin resistant (TTX-R isoforms of voltage-gated sodium channels, NaV1.8 and NaV1.9. These isoforms play key roles in the pathophysiology of chronic pain. Of special interest is NaV1.9: our previous studies revealed a unique property of the NaV1.9 current, i.e., the NaV1.9 current shows a gradual and notable up-regulation of the peak amplitude during recording (“spontaneous augmentation of NaV1.9”. However, the mechanism underlying the spontaneous augmentation of NaV1.9 is still unclear. In this study, we examined the effects of protein kinases A and C (PKA and PKC, on the spontaneous augmentation of NaV1.9. The spontaneous augmentation of the NaV1.9 current was significantly suppressed by activation of PKA, whereas activation of PKA did not affect the voltage dependence of inactivation for the NaV1.9 current. On the contrary, the finding that activation of PKC can affect the voltage dependence of inactivation for NaV1.9 in the perforated patch recordings, where the augmentation does not occur, suggests that the effects of PMA are independent of the augmentation process. These results indicate that the spontaneous augmentation of NaV1.9 was regulated directly by PKA, and indirectly by PKC.

  10. 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.

    Science.gov (United States)

    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.

  11. 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.

  12. Horn Fly, (L.), Overwintering

    OpenAIRE

    Allan T. Showler; Weste L.A. Osbrink; Kimberly H. Lohmeyer

    2014-01-01

    The horn fly, Haematobia irritans irritans (L.), is an ectoparasitic blood feeder mainly on cattle. Its cosmopolitan distribution extends from boreal and grassland regions in northern and southern latitudes to the tropics. Stress and blood loss from horn flies can reduce cattle weight gain and milk production. Horn flies show substantial plasticity in their response to winter. Populations in warmer, lower latitudes have been reported to overwinter in a state of dormancy, but most overwinter a...

  13. Identification of Early RET+ Deep Dorsal Spinal Cord Interneurons in Gating Pain

    Science.gov (United States)

    Cui, Lian; Miao, Xuerong; Liang, Lingli; Abdus-Saboor, Ishmail; Olson, William; Fleming, Michael S; Ma, Minghong; Tao, Yuan-Xiang; Luo, Wenqin

    2016-01-01

    The gate control theory (GCT) of pain proposes that pain- and touch-sensing neurons antagonize each other through spinal cord dorsal horn (DH) gating neurons. However, the exact neural circuits underlying the GCT remain largely elusive. Here, we identified a new population of deep layer DH (dDH) inhibitory interneurons that express the receptor tyrosine kinase Ret neonatally. These early RET+ dDH neurons receive excitatory as well as polysynaptic inhibitory inputs from touch- and/or pain-sensing afferents. In addition, they negatively regulate DH pain and touch pathways through both pre- and postsynaptic inhibition. Finally, specific ablation of early RET+ dDH neurons increases basal and chronic pain, whereas their acute activation reduces basal pain perception and relieves inflammatory and neuropathic pain. Taken together, our findings uncover a novel spinal circuit that mediates crosstalk between touch and pain pathways and suggest that some early RET+ dDH neurons could function as pain “gating” neurons. PMID:27545714

  14. 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

  15. [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

  16. Horn Fly, (L., Overwintering

    Directory of Open Access Journals (Sweden)

    Allan T. Showler

    2014-01-01

    Full Text Available The horn fly, Haematobia irritans irritans (L., is an ectoparasitic blood feeder mainly on cattle. Its cosmopolitan distribution extends from boreal and grassland regions in northern and southern latitudes to the tropics. Stress and blood loss from horn flies can reduce cattle weight gain and milk production. Horn flies show substantial plasticity in their response to winter. Populations in warmer, lower latitudes have been reported to overwinter in a state of dormancy, but most overwinter as active adults in normal or reduced numbers. As latitudes increase, winters are generally colder, and correspondingly, larger percentages of horn fly populations become dormant as pharate adults (a post-pupal, pre-emergent stage or die. Reports on the effect of elevation on horn fly dormancy at high elevations were contradictory. When it occurs, dormancy takes place beneath cattle dung pats and in the underlying soil. The horn fly's mode of dormancy is commonly called diapause, but the collective research on horn fly diapause (behavioral and biochemical is not conclusive. Understanding the horn fly's overwintering behaviors can lead to development of pre-dormancy insecticide spray strategies in colder latitudes while other strategies must be determined for warmer regions.

  17. 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.

  18. Identifying local and descending inputs for primary sensory neurons.

    Science.gov (United States)

    Zhang, Yi; Zhao, Shengli; Rodriguez, Erica; Takatoh, Jun; Han, Bao-Xia; Zhou, Xiang; Wang, Fan

    2015-10-01

    Primary pain and touch sensory neurons not only detect internal and external sensory stimuli, but also receive inputs from other neurons. However, the neuronal derived inputs for primary neurons have not been systematically identified. Using a monosynaptic rabies viruses-based transneuronal tracing method combined with sensory-specific Cre-drivers, we found that sensory neurons receive intraganglion, intraspinal, and supraspinal inputs, the latter of which are mainly derived from the rostroventral medulla (RVM). The viral-traced central neurons were largely inhibitory but also consisted of some glutamatergic neurons in the spinal cord and serotonergic neurons in the RVM. The majority of RVM-derived descending inputs were dual GABAergic and enkephalinergic (opioidergic). These inputs projected through the dorsolateral funiculus and primarily innervated layers I, II, and V of the dorsal horn, where pain-sensory afferents terminate. Silencing or activation of the dual GABA/enkephalinergic RVM neurons in adult animals substantially increased or decreased behavioral sensitivity, respectively, to heat and mechanical stimuli. These results are consistent with the fact that both GABA and enkephalin can exert presynaptic inhibition of the sensory afferents. Taken together, this work provides a systematic view of and a set of tools for examining peri- and extrasynaptic regulations of pain-afferent transmission.

  19. Upregulation of the sodium channel NaVβ4 subunit and its contributions to mechanical hypersensitivity and neuronal hyperexcitability in a rat model of radicular pain induced by local dorsal root ganglion inflammation.

    Science.gov (United States)

    Xie, Wenrui; Tan, Zhi-Yong; Barbosa, Cindy; Strong, Judith A; Cummins, Theodore R; Zhang, Jun-Ming

    2016-04-01

    High-frequency spontaneous firing in myelinated sensory neurons plays a key role in initiating pain behaviors in several different models, including the radicular pain model in which the rat lumbar dorsal root ganglia (DRG) are locally inflamed. The sodium channel isoform NaV1.6 contributes to pain behaviors and spontaneous activity in this model. Among all isoforms in adult DRG, NaV1.6 is the main carrier of tetrodotoxin-sensitive resurgent Na currents that allow high-frequency firing. Resurgent currents flow after a depolarization or action potential, as a blocking particle exits the pore. In most neurons, the regulatory β4 subunit is potentially the endogenous blocker. We used in vivo siRNA-mediated knockdown of NaVβ4 to examine its role in the DRG inflammation model. NaVβ4 but not control siRNA almost completely blocked mechanical hypersensitivity induced by DRG inflammation. Microelectrode recordings in isolated whole DRG showed that NaVβ4 siRNA blocked the inflammation-induced increase in spontaneous activity of Aβ neurons and reduced repetitive firing and other measures of excitability. NaVβ4 was preferentially expressed in larger diameter cells; DRG inflammation increased its expression, and this was reversed by NaVβ4 siRNA, based on immunohistochemistry and Western blotting. NaVβ4 siRNA also reduced immunohistochemical NaV1.6 expression. Patch-clamp recordings of tetrodotoxin-sensitive Na currents in acutely cultured medium diameter DRG neurons showed that DRG inflammation increased transient and especially resurgent current, effects blocked by NaVβ4 siRNA. NaVβ4 may represent a more specific target for pain conditions that depend on myelinated neurons expressing NaV1.6.

  20. Differential Activation of Fast-Spiking and Regular-Firing Neuron Populations During Movement and Reward in the Dorsal Medial Frontal Cortex

    Science.gov (United States)

    Insel, Nathan; Barnes, Carol A.

    2015-01-01

    The medial prefrontal cortex is thought to be important for guiding behavior according to an animal's expectations. Efforts to decode the region have focused not only on the question of what information it computes, but also how distinct circuit components become engaged during behavior. We find that the activity of regular-firing, putative projection neurons contains rich information about behavioral context and firing fields cluster around reward sites, while activity among putative inhibitory and fast-spiking neurons is most associated with movement and accompanying sensory stimulation. These dissociations were observed even between adjacent neurons with apparently reciprocal, inhibitory–excitatory connections. A smaller population of projection neurons with burst-firing patterns did not show clustered firing fields around rewards; these neurons, although heterogeneous, were generally less selective for behavioral context than regular-firing cells. The data suggest a network that tracks an animal's behavioral situation while, at the same time, regulating excitation levels to emphasize high valued positions. In this scenario, the function of fast-spiking inhibitory neurons is to constrain network output relative to incoming sensory flow. This scheme could serve as a bridge between abstract sensorimotor information and single-dimensional codes for value, providing a neural framework to generate expectations from behavioral state. PMID:24700585

  1. Rapid pH and PO2 changes in the tissue recording chamber during stoppage of a gas-equilibrated perfusate: effects on calcium currents in ventral horn neurons.

    Science.gov (United States)

    Carlin, K P; Brownstone, R M

    2006-09-01

    In vitro studies often use bicarbonate-buffered saline solutions to mimic the normal extracellular environment of tissues. These solutions are typically equilibrated with gaseous O2 and CO2, the latter interacting with bicarbonate ions to maintain a physiological pH. In vitro tissue chambers, like those used for electrophysiology, are usually continually perfused with the gassed buffer, but stopping the perfusion to add expensive chemicals or acquire imaging data is a common practice. The present study demonstrates that this procedure leads to rapid (PO2 of the detained solution in the tissue chamber. During the first 200 s, pH increased by 0.4 units and resulted in a 25% PO2 reduction of the detained solution. The rates of these changes were dependent on the volume of solution in the chamber. In experiments using acute transverse slices from the lumbar spinal cord of neonatal (postnatal day 0-10) mice, perfusion stoppage of the same duration was accompanied by a 34.7% enhancement of the peak voltage-gated calcium current recorded from ventral horn neurons. In these cells both low voltage-activated and high voltage-activated currents were affected. These currents were unaffected by decreasing PO2 when a CO2-independent buffer was used, suggesting that changes in pH were responsible for the observed effects. It is concluded that the procedure of stopping a bicarbonate/CO2-buffered perfusate results in rapid changes in pH and PO2 of the solution detained in the tissue chamber, and that these changes have the potential to covertly influence experimental results.

  2. 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.

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

    Science.gov (United States)

    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

  4. Chronic Treatment with NGF Induces Spontaneous Fluctuations of Intracellular Ca(2+) in Icilin-Sensitive Dorsal Root Ganglion Neurons of the Rat

    Czech Academy of Sciences Publication Activity Database

    Kayano, T.; Kitamura, N.; Moriya, A.; Ozaki, Y.; Dayanithi, Govindan; Shibuya, I.

    2010-01-01

    Roč. 72, č. 12 (2010), s. 1531-1538 ISSN 0916-7250 Institutional research plan: CEZ:AV0Z50390703 Keywords : capsaicin * sensory neuron * TRPA1 Subject RIV: FH - Neurology Impact factor: 0.722, year: 2010

  5. PROJECTIONS OF DORSAL AND MEDIAN RAPHE NUCLEI TO DORSAL AND VENTRAL STRIATUM

    Directory of Open Access Journals (Sweden)

    G. R. Hassanzadeh G. Behzadi

    2007-08-01

    Full Text Available The ascending serotonergic projections are derived mainly from mesencephalic raphe nuclei. Topographical projections from mesencephalic raphe nuclei to the striatum were examined in the rat by the retrograde transport technique of HRP (horseradish peroxidase. In 29 rats stereotaxically injection of HRP enzyme were performed in dorsal and ventral parts of striatum separately. The extent of the injection sites and distribution of retrogradely labeled neuronal cell bodies were drawed on representative sections using a projection microscope. Following ipsilateral injection of HRP into the dorsal striatum, numerous labeled neurons were seen in rostral portion of dorsal raphe (DR nucleus. In the same level the cluster of labeled neurons were hevier through caudal parts of DR. A few neurons were also located in lateral wing of DR. More caudally some labeled neurons were found in lateral, medial line of DR. In median raphe nucleus (MnR the labeled neurons were scattered only in median portion of this nucleus. The ipsilateral injection of HRP into the ventral region of striatum resulted on labeling of numerous neurons in rostral, caudal and lateral portions of DR. Through the caudal extension of DR on 4th ventricle level, a large number of labeled neurons were distributed along the ventrocaudal parts of DR. In MnR, labeled neurons were observed only in median part of this nucleus. These findings suggest the mesencephalic raphe nuclei projections to caudo-putamen are topographically organized. In addition dorsal and median raphe nuclei have a stronger projection to the ventral striatum.

  6. Prurigo Nodularis With Cutaneous Horn

    Directory of Open Access Journals (Sweden)

    Thadeus Joseph

    1997-01-01

    Full Text Available Cutaneous horns are rare horny excrescences which occur in various dermatoses. We report a girl with prurigo nodularis who developed a horn on one of the nodules. This unique association has not been reported so far.

  7. Iterative Specialisation of Horn Clauses

    DEFF Research Database (Denmark)

    Nielsen, Christoffer Rosenkilde; Nielson, Flemming; Nielson, Hanne Riis

    2008-01-01

    We present a generic algorithm for solving Horn clauses through iterative specialisation. The algorithm is generic in the sense that it can be instantiated with any decidable fragment of Horn clauses, resulting in a solution scheme for general Horn clauses that guarantees soundness and termination...

  8. Exposure to an open-field arena increases c-Fos expression in a subpopulation of neurons in the dorsal raphe nucleus, including neurons projecting to the basolateral amygdaloid complex

    DEFF Research Database (Denmark)

    Hale, M.W.; Hay-Schmidt, A.; Mikkelsen, J.D.

    2008-01-01

    . Treatment effects on c-Fos expression in serotonergic and non-serotonergic cells in the midbrain raphe nuclei were determined 2 h following open-field exposure or home cage control (CO) conditions. Rats tested under both light conditions responded with increases in c-Fos expression in serotonergic neurons...... of neurons in the midbrain raphe complex that projects to forebrain circuits regulating anxiety states, we used cholera toxin B subunit (CTb) as a retrograde tracer to identify neurons projecting to the basolateral amygdaloid complex (BL) in combination with c-Fos immunostaining to identify cells...

  9. Antidepressant Imipramine Protects Bupivacaine-Induced Neurotoxicity in Dorsal Root Ganglion Neurons Through Coactivation of TrkA and TrkB.

    Science.gov (United States)

    Guo, Jianrong; Wang, Huan; Tao, Qiang; Sun, Shiyu; Liu, Li; Zhang, Jianping; Yang, Dawei

    2017-11-01

    In our work, we used an in vitro culture model to investigate whether antidepressant imipramine (Ip) may protect bupivacaine (Bv)-induced neurotoxicity in mouse dorsal root ganglion (DRG). Adult mouse DRG was treated with 5 mM Bv in vitro to induce neurotoxicity. DRG was then pre-treated with Ip, prior to Bv, to examine its effects on protecting Bv-induced DRG apoptosis and neurite degeneration. Ip-induced dynamic changes in Trk receptors, including TrkA/B/C and phosphor (p-)TrkA/B/C, were examined by qPCR and Western blot. TrkA and TrkB were inhibited by siRNAs to further investigate their functional role in Ip- and Bv-treated DRG. Ip protected Bv-induced apoptosis and neurite loss in DRG. Ip did not alter TrkA/B/C expressions, whereas significantly augmented protein productions of p-TrkA and p-TrkB, but not p-TrkC. SiRNA-mediated TrkA or TrkB downregulation inhibited Trk receptors, and reduced p-TrkA and p-TrkB in DRG. TrkA or TrkB downregulation alone had no effect on Ip-induced protection in Bv-injured DRG. However, co-inhibition of TrkA and TrkB significantly ameliorated the protective effect of Ip on Bv-induced apoptosis and neurite loss in DRG. Imipramine protected bupivacaine-induced neurotoxicity in DRG, likely via the co-activation of TrkA and TrkB signaling pathways. J. Cell. Biochem. 118: 3960-3967, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. Microstimulation of primary afferent neurons in the L7 dorsal root ganglia using multielectrode arrays in anesthetized cats: thresholds and recruitment properties

    Science.gov (United States)

    Gaunt, R. A.; Hokanson, J. A.; Weber, D. J.

    2009-10-01

    Current research in motor neural prosthetics has focused primarily on issues related to the extraction of motor command signals from the brain (e.g. brain-machine interfaces) to direct the motion of prosthetic limbs. Patients using these types of systems could benefit from a somatosensory neural interface that conveys natural tactile and kinesthetic sensations for the prosthesis. Electrical microstimulation within the dorsal root ganglia (DRG) has been proposed as one method to accomplish this, yet little is known about the recruitment properties of electrical microstimulation in activating nerve fibers in this structure. Current-controlled microstimulation pulses in the range of 1-15 µA (200 µs, leading cathodic pulse) were delivered to the L7 DRG in four anesthetized cats using penetrating microelectrode arrays. Evoked responses and their corresponding conduction velocities (CVs) were measured in the sciatic nerve with a 5-pole nerve cuff electrode arranged as two adjacent tripoles. It was found that in 76% of the 69 electrodes tested, the stimulus threshold was less than or equal to 3 µA, with the lowest recorded threshold being 1.1 µA. The CVs of afferents recruited at threshold had a bimodal distribution with peaks at 70 m s-1 and 85 m s-1. In 53% of cases, the CV of the response at threshold was slower (i.e. smaller diameter fiber) than the CVs of responses observed at increasing stimulation amplitudes. In summary, we found that microstimulation applied through penetrating microelectrodes in the DRG provides selective recruitment of afferent fibers from a range of sensory modalities (as identified by CVs) at very low stimulation intensities. We conclude that the DRG may serve as an attractive location from which to introduce surrogate somatosensory feedback into the nervous system.

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

    Directory of Open Access Journals (Sweden)

    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

  12. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Magnetic Focusing Horn

    CERN Multimedia

    1974-01-01

    This magnetic focusing horn was used for the AA (antiproton accumulator). Its development was an important step towards using CERN's Super Proton Synchrotron as a proton - antiproton collider. This eventually led to the discovery of the W and Z particles in 1983. Making an antiproton beam took a lot of time and effort. Firstly, protons were accelerated to an energy of 26 GeV in the PS and ejected onto a metal target. From the spray of emerging particles, a magnetic horn picked out 3.6 GeV antiprotons for injection into the AA through a wide-aperture focusing quadrupole magnet. For a million protons hitting the target, just one antiproton was captured, 'cooled' and accumulated. It took 3 days to make a beam of 3 x 10^11 -, three hundred thousand million - antiprotons.

  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. The Folded Horn Antenna

    Science.gov (United States)

    Farr, E. G.; Bowen, L. H.; Baum, C. E.; Prather, W. D.

    Antennas for radiating high-power mesoband (medium-bandwidth) electromagnetic signals are critical to the mission of upsetting electronics at a distance. When operated at frequencies of a few hundred megahertz, RF weapons require highly efficient antennas that can fit into a small volume. Most of the existing antennas, such as pyramidal horns, are too large to fit onto certain platforms of interest. To address this challenge, we investigate the folded horn, which has aperture dimensions of 0.5 × 2 wavelengths, and a depth of 1.5-2 wavelengths. This antenna has a nearly focused aperture field, due to a parabolic fold in the H-plane. We report here on the fabrication and testing of the first folded horn, operating at 3 GHz. After a number of iterations, we obtained a realized gain of at least 10 dBi over 3-5 GHz, an aperture efficiency of 80%, and a return loss below -10 dB over 2.8-3.35 GHz. This design could be adapted to high-voltages, and it could work well in a two-antenna array, with two antennas positioned back to back, driven by a differential source.

  18. 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.

  19. Horn installed in CNGS tunnel

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The horn is installed for the CERN Neutrinos to Gran Sasso (CNGS) project. Protons collide with a graphite target producing charged particles that are focussed by the magnetic field in the horn. These particles will then pass into a decay tube where they decay into neutrinos, which travel towards a detector at Gran Sasso 732 km away in Italy.

  20. 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

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

    Science.gov (United States)

    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

  2. The Overexpression of TDP-43 Protein in the Neuron and Oligodendrocyte Cells Causes the Progressive Motor Neuron Degeneration in the SOD1 G93A Transgenic Mouse Model of Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Lu, Yi; Tang, Chunyan; Zhu, Lei; Li, Jiao; Liang, Huiting; Zhang, Jie; Xu, Renshi

    2016-01-01

    The recent investigation suggested that the TDP-43 protein was closely related to the motor neuron degeneration in amyotrophic lateral sclerosis (ALS), but the pathogenesis contributed to motor neuron degeneration largely remained unknown. Therefore, we detected the alteration of TDP-43 expression and distribution in the adult spinal cord of the SOD1 G93A transgenic mouse model for searching the possible pathogenesis of ALS. We examined the TDP-43 expression and distribution in the different anatomic regions, segments and neural cells in the adult spinal cord at the different stages of the SOD1 wild-type and G93A transgenic model by the fluorescent immunohistochemical technology. We revealed that the amount of TDP-43 positive cell was cervical>lumbar>thoracic segment, that in the ventral horn was more than that in the dorsal horn, a few of TDP-43 protein sparsely expressed and distributed in the other regions, the TDP-43 protein weren't detected in the white matter and the central canal. The TDP-43 protein was mostly expressed and distributed in the nuclear of neuron cells and the cytoplasm of oligodendrocyte cells of the gray matter surrounding the central canal of spinal cord by the granular shape in the SOD1 wild-type and G93A transgenic mice. The amount of TDP-43 positive cell significantly increased at the onset and progression stages of ALS following with the increase of neuron death in spinal cord, particularly in the ventral horn of cervical segment at the progression stage. Our results suggested that the overexpression of TDP-43 protein in the neuron and oligodendrocyte cell causes the progressive motor neuron degeneration in the ALS-like mouse model.

  3. 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

  4. DORSAL MESENCEPHALIC PROJECTIONS TO PONS, MEDULLA, AND SPINAL-CORD IN THE CAT - LIMBIC AND NONLIMBIC COMPONENTS

    NARCIS (Netherlands)

    COWIE, RJ; HOLSTEGE, G

    1992-01-01

    The vertebrate dorsal mesencephalon consists of the superior colliculus, the dorsal portion of the periaqueductal gray, and the mesencephalic trigeminal neurons in between. These structures, via their descending pathways, take part in various behavioral responses to environmental stimuli. This study

  5. Neuroimmune and Neuropathic Responses of Spinal Cord and Dorsal Root Ganglia in Middle Age

    Science.gov (United States)

    Galbavy, William; Kaczocha, Martin; Puopolo, Michelino; Liu, Lixin; Rebecchi, Mario J.

    2015-01-01

    Prior studies of aging and neuropathic injury have focused on senescent animals compared to young adults, while changes in middle age, particularly in the dorsal root ganglia (DRG), have remained largely unexplored. 14 neuroimmune mRNA markers, previously associated with peripheral nerve injury, were measured in multiplex assays of lumbar spinal cord (LSC), and DRG from young and middle-aged (3, 17 month) naïve rats, or from rats subjected to chronic constriction injury (CCI) of the sciatic nerve (after 7 days), or from aged-matched sham controls. Results showed that CD2, CD3e, CD68, CD45, TNF-α, IL6, CCL2, ATF3 and TGFβ1 mRNA levels were substantially elevated in LSC from naïve middle-aged animals compared to young adults. Similarly, LSC samples from older sham animals showed increased levels of T-cell and microglial/macrophage markers. CCI induced further increases in CCL2, and IL6, and elevated ATF3 mRNA levels in LSC of young and middle-aged adults. Immunofluorescence images of dorsal horn microglia from middle-aged naïve or sham rats were typically hypertrophic with mostly thickened, de-ramified processes, similar to microglia following CCI. Unlike the spinal cord, marker expression profiles in naïve DRG were unchanged across age (except increased ATF3); whereas, levels of GFAP protein, localized to satellite glia, were highly elevated in middle age, but independent of nerve injury. Most neuroimmune markers were elevated in DRG following CCI in young adults, yet middle-aged animals showed little response to injury. No age-related changes in nociception (heat, cold, mechanical) were observed in naïve adults, or at days 3 or 7 post-CCI. The patterns of marker expression and microglial morphologies in healthy middle age are consistent with development of a para-inflammatory state involving microglial activation and T-cell marker elevation in the dorsal horn, and neuronal stress and satellite cell activation in the DRG. These changes, however, did not

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

    Science.gov (United States)

    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. Dipole-like neuronal sources of theta rhythm in dorsal hippocampus, dendate gyrus and cingulate cortex of the urethane-anesthetized rat = Sources neuronales, de type dipolaire, du rythme thêta dans l'hippocampe dorsal, le gyrus dentatus et le cortex cingulaire du rat anesthésié à l'uréthane

    NARCIS (Netherlands)

    Feenstra, B.W.A.; Holsheimer, J.

    1979-01-01

    Spatial distribution of theta activity was investigated in the dorsal hippocampal formation and overlying neocortex of the urethaneanesthetized rat. Laminar phase profiles from semi-microelectrode penetrations showed approximately 180° phase shifts combined with small amplitude values in stratum

  8. Anti-inflammatory effects of dexamethasone and meloxicam on Borrelia burgdorferi-induced inflammation in neuronal cultures of dorsal root ganglia and myelinating cells of the peripheral nervous system.

    Science.gov (United States)

    Ramesh, Geeta; Meisner, Olivia C; Philipp, Mario T

    2015-12-23

    Lyme neuroborreliosis (LNB), caused by the spirochete Borrelia burgdorferi (Bb), could result in cognitive impairment, motor dysfunction, and radiculoneuritis. We hypothesized that inflammation is a key factor in LNB pathogenesis and recently evaluated the effects of dexamethasone, a steroidal anti-inflammatory drug, and meloxicam a non-steroidal anti-inflammatory drug (NSAID), in a rhesus monkey model of acute LNB. Dexamethasone treatment significantly reduced the levels of immune mediators, and prevented inflammatory and/or neurodegenerative lesions in the central and peripheral nervous systems, and apoptosis in the dorsal root ganglia (DRG). However, infected animals treated with meloxicam showed levels of inflammatory mediators, inflammatory lesions, and DRG cell apoptosis that were similar to that of the infected animals that were left untreated. To address the differential anti-inflammatory effects of dexamethasone and meloxicam on neuronal and myelinating cells of the peripheral nervous system (PNS), we evaluated the potential of these drugs to alter the levels of Bb-induced inflammatory mediators in rhesus DRG cell cultures and primary human Schwann cells (HSC), using multiplex enzyme-linked immunosorbent assays (ELISA). We also ascertained the ability of these drugs to modulate cell death as induced by live Bb in HSC using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) viability assay and the potential of dexamethasone to modulate Bb-induced apoptosis in HSC by the TUNEL assay. Earlier, we reported that dexamethasone significantly reduced Bb-induced immune mediators and apoptosis in rhesus DRG cell cultures. Here, we report that dexamethasone but not meloxicam significantly reduces the levels of several cytokines and chemokines as induced by live Bb, in HSC and DRG cell cultures. Further, meloxicam does not significantly alter Bb-induced cell death in HSC, while dexamethasone protects HSC against Bb-induced cell death. These data

  9. Ancient celtic horns

    Science.gov (United States)

    Campbell, Murray

    2002-11-01

    There is considerable evidence from iconographic and documentary sources that musical lip-reed instruments were important in the early celtic communities of Scotland and Ireland. In recent years several studies have been undertaken with the aim of gaining a better understanding of the musical nature of these ancient horns, and of their place in the life and culture of the time. A valuable source of tangible evidence is to be found in the archaeological remains deposited across Scotland and the whole of Ireland. A project is now under way, under the auspices of the Kilmartin House Trust and the general direction of John Purser, which has brought together an international team of musicians, craftsmen, archaeologists, musicologists and physicists with the aim of analyzing ancient musical artifacts, reconstructing some of the original instruments, and analyzing the sounds they produce. This paper describes acoustical studies carried out on a number of recent reconstructions of wooden and bronze instruments, and discusses the role of acoustics in this type of investigation. [Work supported by Sciart and EPSRC.

  10. Acupuncture Points and Their Relationship with Multireceptive Fields of Neurons

    Directory of Open Access Journals (Sweden)

    Salvador Quiroz-González

    2017-04-01

    Full Text Available 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. By considering that a particular AP location involves the activation of one or various RFs, it can be assumed that several sensory central neurons are the site of convergence of the peripheral input generated by acupuncture stimulation. However, stimulation on nonacupoint sites could also activate skin areas with RFs that have been sensitized, and they could be involved in the generation of nonspecific effects of acupuncture, as seen in clinical practice. From the latter, it is suggested that effective APs, and even nonacupoints, are associated with a particular arrangement of RFs, and their study will be useful for understanding the intrinsic mechanisms of acupuncture and for the development and identification of more efficient sites and modes of acupuncture stimulation to evoke optimal therapeutic actions.

  11. 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.

  12. Peripheral nerve injury induces trans-synaptic modification of channels, receptors and signal pathways in rat dorsal spinal cord.

    Science.gov (United States)

    Yang, Liang; Zhang, Fang-Xiong; Huang, Fen; Lu, Yin-Jing; Li, Guo-Dong; Bao, Lan; Xiao, Hua-Sheng; Zhang, Xu

    2004-02-01

    Peripheral tissue injury-induced central sensitization may result from the altered biochemical properties of spinal dorsal horn. However, peripheral nerve injury-induced modification of genes in the dorsal horn remains largely unknown. Here we identified strong changes of 14 channels, 25 receptors and 42 signal transduction related molecules in Sprague-Dawley rat dorsal spinal cord 14 days after peripheral axotomy by cDNA microarray. Twenty-nine genes were further confirmed by semiquantitative RT-PCR, Northern blotting, in situ hybridization and immunohistochemistry. These regulated genes included Ca2+ channel alpha1E and alpha2/delta1 subunits, alpha subunits for Na+ channel 1 and 6, Na+ channel beta subunit, AMAP receptor GluR3 and 4, GABAA receptor alpha5 subunit, nicotinic acetylcholine receptor alpha5 and beta2 subunits, PKC alpha, betaI and delta isozymes, JNK1-3, ERK2-3, p38 MAPK and BatK and Lyn tyrosine-protein kinases, indicating that several signal transduction pathways were activated in dorsal spinal cord by peripheral nerve injury. These results demonstrate that peripheral nerve injury causes phenotypic changes in spinal dorsal horn. Increases in Ca2+ channel alpha2/delta1 subunit, GABAA receptor alpha5 subunit, Na+ channels and nicotinic acetylcholine receptors in both dorsal spinal cord and dorsal root ganglia indicate their potential roles in neuropathic pain control.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Neuronal P2X7 receptor-induced reactive oxygen species production contributes to nociceptive behavior in mice.

    Science.gov (United States)

    Munoz, Frances M; Gao, Ruby; Tian, Yuzhen; Henstenburg, Brian A; Barrett, James E; Hu, Huijuan

    2017-06-14

    ATP can activate a variety of pathways through P2 purinoreceptors, leading to neuroprotection and pathology in the CNS. Among all P2X receptors, the P2X7 receptor (P2X7R) is a well-defined therapeutic target for inflammatory and neuropathic pain. Activation of P2X7R can generate reactive oxygen species (ROS) in macrophages and microglia. However, the role of ROS in P2X7R-induced pain remains unexplored. Here, we investigated the downstream effects of neuronal P2X7R activation in the spinal cord. We found that ATP induces ROS production in spinal cord dorsal horn neurons, an effect eliminated by ROS scavenger N-tert-butyl-α-phenylnitrone (PBN) and P2X7R antagonist A438079. A similar effect was observed with a P2X7R agonist, BzATP, and was attenuated by a NADPH oxidase inhibitor apocynin. Intrathecal administration of BzATP resulted in ROS production in the spinal cord and oxidative DNA damage in dorsal horn neurons. BzATP also induced robust biphasic spontaneous nociceptive behavior. Pre-treatment with A438079 abolished all BzATP-induced nociceptive behaviors, while ROS scavengers dose-dependently attenuated the secondary response. Here, we provide evidence that neuronal P2X7R activation leads to ROS production and subsequent nociceptive pain in mice. Together, the data indicate that P2X7R-induced ROS play a critical role in the P2X7R signaling pathway of the CNS.

  15. 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.

  16. Alleviating Bone Cancer-induced Mechanical Hypersensitivity by Inhibiting Neuronal Activity in the Anterior Cingulate Cortex.

    Science.gov (United States)

    Chiou, Chiuan-Shiou; Chen, Chien-Chung; Tsai, Tsung-Chih; Huang, Chiung-Chun; Chou, Dylan; Hsu, Kuei-Sen

    2016-10-01

    The anterior cingulate cortex (ACC) is a brain region that has been critically implicated in the processing of pain perception and modulation. While much evidence has pointed to an increased activity of the ACC under chronic pain states, less is known about whether pain can be alleviated by inhibiting ACC neuronal activity. The authors used pharmacologic, chemogenetic, and optogenetic approaches in concert with viral tracing technique to address this issue in a mouse model of bone cancer-induced mechanical hypersensitivity by intratibia implantation of osteolytic fibrosarcoma cells. Bilateral intra-ACC microinjections of γ-aminobutyric acid receptor type A receptor agonist muscimol decreased mechanical hypersensitivity in tumor-bearing mice (n =10). Using adenoviral-mediated expression of engineered Gi/o-coupled human M4 (hM4Di) receptors, we observed that activation of Gi/o-coupled human M4 receptors with clozapine-N-oxide reduced ACC neuronal activity and mechanical hypersensitivity in tumor-bearing mice (n = 11). In addition, unilateral optogenetic silencing of ACC excitatory neurons with halorhodopsin significantly decreased mechanical hypersensitivity in tumor-bearing mice (n = 4 to 9), and conversely, optogenetic activation of these neurons with channelrhodopsin-2 was sufficient to provoke mechanical hypersensitivity in sham-operated mice (n = 5 to 9). Furthermore, we found that excitatory neurons in the ACC send direct descending projections to the contralateral dorsal horn of the lumbar spinal cord via the dorsal corticospinal tract. The findings of this study indicate that enhanced neuronal activity in the ACC contributes to maintain bone cancer-induced mechanical hypersensitivity and suggest that the ACC may serve as a potential therapeutic target for treating bone cancer pain.

  17. Activation of Brainstem Neurons by Underwater Diving in the Rat

    Science.gov (United States)

    Panneton, W. Michael; Gan, Qi; Le, Jason; Livergood, Robert S.; Clerc, Philip; Juric, Rajko

    2012-01-01

    The mammalian diving response is a powerful autonomic adjustment to underwater submersion greatly affecting heart rate, arterial blood pressure, and ventilation. The bradycardia is mediated by the parasympathetic nervous system, arterial blood pressure is mediated via the sympathetic system and still other circuits mediate the respiratory changes. In the present study we investigate the cardiorespiratory responses and the brainstem neurons activated by voluntary diving of trained rats, and, compare them to control and swimming animals which did not dive. We show that the bradycardia and increase in arterial blood pressure induced by diving were significantly different than that induced by swimming. Neuronal activation was calculated after immunohistochemical processing of brainstem sections for Fos protein. Labeled neurons were counted in the caudal pressor area, the medullary dorsal horn, subnuclei of the nucleus tractus solitarii (NTS), the nucleus raphe pallidus (RPa), the rostroventrolateral medulla, the A5 area, the nucleus locus coeruleus, the Kölliker–Fuse area, and the external lateral and superior lateral subnuclei of the parabrachial nucleus. All these areas showed significant increases in Fos labeling when data from voluntary diving rats were compared to control rats and all but the commissural subnucleus of the NTS, A5 area, and RPa were significantly different from swimming rats. These data provide a substrate for more precise experiments to determine the role of these nuclei in the reflex circuits driving the diving response. PMID:22563319

  18. Activation of brainstem neurons by underwater diving in the rat

    Directory of Open Access Journals (Sweden)

    W Michael ePanneton

    2012-05-01

    Full Text Available The mammalian diving response is a powerful autonomic adjustment to underwater submersion greatly affecting heart rate, arterial blood pressure and ventilation. The bradycardia is known to be mediated by the parasympathetic nervous system, arterial blood pressure is mediated via the sympathetic system and still other circuits mediate the respiratory changes. In the present study we investigate the cardiorespiratory responses and the brainstem neurons activated by voluntary diving of trained rats, and, compare them to control and swimming animals which did not dive. We show that the bradycardia and increase in arterial blood pressure induced by diving were significantly different that induced by swimming. Neuronal activation was calculated after immunohistochemical processing of brainstem sections for Fos protein. Labeled neurons were counted in the caudal pressor area, the medullary dorsal horn, subnuclei of the nucleus tractus solitarii, the nucleus raphe pallidus, the rostroventrolateral medulla, the A5 area, the nucleus locus coeruleus, the Kölliker-Fuse area and the external lateral and superior lateral subnuclei of the parabrachial nucleus. All these areas showed significant increases in Fos labeling when data from voluntary diving rats were compared to control rats and all but the commissural subnucleus of the nucleus tractus solitarii, A5 area, and raphe pallidus were different from swimming rats. These data provide a substrate for more precise experiments to determine the role of these nuclei in the reflex circuits driving the diving response.

  19. Kamillo Horn und das Melodram

    Czech Academy of Sciences Publication Activity Database

    Bajgarová, Jitka

    2010-01-01

    Roč. 12, - (2010), s. 229-237 ISSN 1212-1193. [Zdeněk Fibich, středoevropský skladatel konce 19. století. Olomouc, 19.05.2010–21.05.2010] Institutional research plan: CEZ:AV0Z90580513 Keywords : Kamillo Horn * concert melodrama Subject RIV: AL - Art, Architecture, Cultural Heritage

  20. Sensory Neurons Derived from Diabetic Rats Have Diminished Internal Ca2+ Stores Linked to Impaired Re-uptake by the Endoplasmic Reticulum

    Directory of Open Access Journals (Sweden)

    Elena Zherebitskaya

    2011-12-01

    Full Text Available Distal symmetrical sensory neuropathy in diabetes involves the dying back of axons, and the pathology equates with axonal dystrophy generated under conditions of aberrant Ca2+ signalling. Previous work has described abnormalities in Ca2+ homoeostasis in sensory and dorsal horn neurons acutely isolated from diabetic rodents. We extended this work by testing the hypothesis that sensory neurons exposed to long-term Type 1 diabetes in vivo would exhibit abnormal axonal Ca2+ homoeostasis and focused on the role of SERCA (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase. DRG (dorsal root ganglia sensory neurons from age-matched normal and 3–5-month-old STZ (streptozotocin-diabetic rats (an experimental model of Type 1 diabetes were cultured. At 1–2 days in vitro an array of parameters were measured to investigate Ca2+ homoeostasis including (i axonal levels of intracellular Ca2+, (ii Ca2+ uptake by the ER (endoplasmic reticulum, (iii assessment of Ca2+ signalling following a long-term thapsigargin-induced blockade of SERCA and (iv determination of expression of ER mass and stress markers using immunocytochemistry and Western blotting. KCl- and caffeine-induced Ca2+ transients in axons were 2-fold lower in cultures of diabetic neurons compared with normal neurons indicative of reduced ER calcium loading. The rate of uptake of Ca2+ into the ER was reduced by 2-fold (P<0.05 in diabetic neurons, while markers for ER mass and ER stress were unchanged. Abnormalities in Ca2+ homoeostasis in diabetic neurons could be mimicked via long-term inhibition of SERCA in normal neurons. In summary, axons of neurons from diabetic rats exhibited aberrant Ca2+ homoeostasis possibly triggered by suboptimal SERCA activity that could contribute to the distal axonopathy observed in diabetes.

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

    Science.gov (United States)

    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

  2. Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve.

    Science.gov (United States)

    McCulloch, Paul F; Warren, Erik A; DiNovo, Karyn M

    2016-01-01

    This research was designed to investigate the role of the anterior ethmoidal nerve (AEN) during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N = 24) were trained to swim and dive through a 5 m underwater maze. Some rats (N = 12) had bilateral sectioning of the AEN, others a Sham surgery (N = 12). Twelve rats (6 AEN cut and 6 Sham) had 24 post-surgical dive trials over 2 h to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kölliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus, the AENs are not required for initiation of the diving response. Other nerve(s) that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response.

  3. Neuronal Activity Stimulated by Liquid Substrates Injection at Zusanli (ST36 Acupoint: The Possible Mechanism of Aquapuncture

    Directory of Open Access Journals (Sweden)

    Chun-Yen Chen

    2014-01-01

    Full Text Available Aquapuncture is a modified acupuncture technique and it is generally accepted that it has a greater therapeutic effect than acupuncture because of the combination of the acupoint stimulation and the pharmacological effect of the drugs. However, to date, the mechanisms underlying the effects of aquapuncture remain unclear. We hypothesized that both the change in the local spatial configuration and the substrate stimulation of aquapuncture would activate neuronal signaling. Thus, bee venom, normal saline, and vitamins B1 and B12 were injected into a Zusanli (ST36 acupoint as substrate of aquapuncture, whereas a dry needle was inserted into ST36 as a control. After aquapuncture, activated neurons expressing Fos protein were mainly observed in the dorsal horn of the spinal cord in lumbar segments L3–5, with the distribution nearly identical among all groups. However, the bee venom injection induced significantly more Fos-expressing neurons than the other substrates. Based on these data, we suggest that changes in the spatial configuration of the acupoint activate neuronal signaling and that bee venom may further strengthen this neuronal activity. In conclusion, the mechanisms for the effects of aquapuncture appear to be the spatial configuration changes occurring within the acupoint and the ability of injected substrates to stimulate neuronal activity.

  4. Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve

    Science.gov (United States)

    McCulloch, Paul F.; Warren, Erik A.; DiNovo, Karyn M.

    2016-01-01

    This research was designed to investigate the role of the anterior ethmoidal nerve (AEN) during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N = 24) were trained to swim and dive through a 5 m underwater maze. Some rats (N = 12) had bilateral sectioning of the AEN, others a Sham surgery (N = 12). Twelve rats (6 AEN cut and 6 Sham) had 24 post-surgical dive trials over 2 h to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kölliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus, the AENs are not required for initiation of the diving response. Other nerve(s) that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response. PMID:27148082

  5. 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.

  6. Presynaptic Inputs to Any CNS Projection Neuron Identified by Dual Recombinant Virus Infection.

    Science.gov (United States)

    Bráz, João M; Wang, Fan; Basbaum, Allan I

    2015-01-01

    Although neuroanatomical tracing studies have defined the origin and targets of major projection neurons (PN) of the central nervous system (CNS), there is much less information about the circuits that influence these neurons. Recently, genetic approaches that use Cre recombinase-dependent viral vectors have greatly facilitated such circuit analysis, but these tracing approaches are limited by the availability of Cre-expressing mouse lines and the difficulty in restricting Cre expression to discrete regions of the CNS. Here, we illustrate an alternative approach to drive Cre expression specifically in defined subsets of CNS projection neurons, so as to map both direct and indirect presynaptic inputs to these cells. The method involves a combination of Cre-dependent transneuronal viral tracers that can be used in the adult and that does not require genetically modified mice. To trigger Cre-expression we inject a Cre-expressing adenovirus that is retrogradely transported to the projection neurons of interest. The region containing the retrogradely labeled projection neurons is next injected with Cre-dependent pseudorabies or rabies vectors, which results in labeling of poly- and monosynaptic neuronal inputs, respectively. In proof-of-concept experiments, we used this novel tracing system to study the circuits that engage projection neurons of the superficial dorsal horn of the spinal cord and trigeminal nucleus caudalis, neurons of the parabrachial nucleus of the dorsolateral pons that project to the amygdala and cortically-projecting neurons of the lateral geniculate nucleus. Importantly, because this dual viral tracing method does not require genetically derived Cre-expressing mouse lines, inputs to almost any projection system can be studied and the analysis can be performed in larger animals, such as the rat.

  7. Presynaptic Inputs to Any CNS Projection Neuron Identified by Dual Recombinant Virus Infection.

    Directory of Open Access Journals (Sweden)

    João M Bráz

    Full Text Available Although neuroanatomical tracing studies have defined the origin and targets of major projection neurons (PN of the central nervous system (CNS, there is much less information about the circuits that influence these neurons. Recently, genetic approaches that use Cre recombinase-dependent viral vectors have greatly facilitated such circuit analysis, but these tracing approaches are limited by the availability of Cre-expressing mouse lines and the difficulty in restricting Cre expression to discrete regions of the CNS. Here, we illustrate an alternative approach to drive Cre expression specifically in defined subsets of CNS projection neurons, so as to map both direct and indirect presynaptic inputs to these cells. The method involves a combination of Cre-dependent transneuronal viral tracers that can be used in the adult and that does not require genetically modified mice. To trigger Cre-expression we inject a Cre-expressing adenovirus that is retrogradely transported to the projection neurons of interest. The region containing the retrogradely labeled projection neurons is next injected with Cre-dependent pseudorabies or rabies vectors, which results in labeling of poly- and monosynaptic neuronal inputs, respectively. In proof-of-concept experiments, we used this novel tracing system to study the circuits that engage projection neurons of the superficial dorsal horn of the spinal cord and trigeminal nucleus caudalis, neurons of the parabrachial nucleus of the dorsolateral pons that project to the amygdala and cortically-projecting neurons of the lateral geniculate nucleus. Importantly, because this dual viral tracing method does not require genetically derived Cre-expressing mouse lines, inputs to almost any projection system can be studied and the analysis can be performed in larger animals, such as the rat.

  8. Folded Resonant Horns for Power Ultrasonic Applications

    Science.gov (United States)

    Sherrit, Stewart; Askins, Stephen; Gradziel, Michael; Bao, Xiaoqi; Chang, Zensheu; Dolgin, Benjamin; Bar-Cohen, Yoseph; Peterson, Tom

    2003-01-01

    Folded horns have been conceived as alternatives to straight horns used as resonators and strain amplifiers in power ultrasonic systems. Such systems are used for cleaning, welding, soldering, cutting, and drilling in a variety of industries. In addition, several previous NASA Tech Briefs articles have described instrumented drilling, coring, and burrowing machines that utilize combinations of sonic and ultrasonic vibrational actuation. The main advantage of a folded horn, relative to a straight horn of the same resonance frequency, is that the folded horn can be made shorter (that is, its greatest linear dimension measured from the outside can be made smaller). Alternatively, for a given length, the resonance frequency can be reduced. Hence, the folded-horn concept affords an additional degree of design freedom for reducing the length of an ultrasonic power system that includes a horn.

  9. 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.)

  10. 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

  11. An anatomical study of the propriospinal connections in the cat

    NARCIS (Netherlands)

    W.M. Molenaar

    1977-01-01

    textabstractIn the spinal cord the neuronal cell bodies are located in the spinal gray matter, which may be subdivided into a dorsal horn, a ventral horn and an intermediate zone. Neurons in the dorsal horn give rise mainly to long ascending fibers, while the motoneurons of the ventral horn

  12. 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...

  13. Ca2+ -Mediated Plateau Potentials in a Subpopulation of Interneurons in the Ventral Horn of the Turtle Spinal Cord

    DEFF Research Database (Denmark)

    Hounsgaard, J.; Kjaerulff, O.

    1992-01-01

    The response properties of interneurons in the ventral horn were studied in transverse slices of segments D8 to S2 from the turtle spinal cord, using the current clamp technique. In about half of the neurons the response properties were dominated by their ability to generate plateau potentials...... root and occasionally from the contralateral root. The plateau potential was insensitive to tetrodotoxin but blocked by nifedipine and by replacing Ca2+ with Co2+ in the medium. It is concluded that the response properties of neurons in the ventral horn outside the motor nucleus have differentiated...

  14. 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.

  15. 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.

  16. Fractal characterization of acupuncture-induced spike trains of rat WDR neurons

    International Nuclear Information System (INIS)

    Chen, Yingyuan; Guo, Yi; Wang, Jiang; Hong, Shouhai; Wei, Xile; Yu, Haitao; Deng, Bin

    2015-01-01

    Highlights: •Fractal analysis is a valuable tool for measuring MA-induced neural activities. •In course of the experiments, the spike trains display different fractal properties. •The fractal properties reflect the long-term modulation of MA on WDR neurons. •The results may explain the long-lasting effects induced by acupuncture. -- Abstract: The experimental and the clinical studies have showed manual acupuncture (MA) could evoke multiple responses in various neural regions. Characterising the neuronal activities in these regions may provide more deep insights into acupuncture mechanisms. This paper used fractal analysis to investigate MA-induced spike trains of Wide Dynamic Range (WDR) neurons in rat spinal dorsal horn, an important relay station and integral component in processing acupuncture information. Allan factor and Fano factor were utilized to test whether the spike trains were fractal, and Allan factor were used to evaluate the scaling exponents and Hurst exponents. It was found that these two fractal exponents before and during MA were different significantly. During MA, the scaling exponents of WDR neurons were regulated in a small range, indicating a special fractal pattern. The neuronal activities were long-range correlated over multiple time scales. The scaling exponents during and after MA were similar, suggesting that the long-range correlations not only displayed during MA, but also extended to after withdrawing the needle. Our results showed that fractal analysis is a useful tool for measuring acupuncture effects. MA could modulate neuronal activities of which the fractal properties change as time proceeding. This evolution of fractal dynamics in course of MA experiments may explain at the level of neuron why the effect of MA observed in experiment and in clinic are complex, time-evolutionary, long-range even lasting for some time after stimulation

  17. AA, sandwich line with magnetic horn

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    Continuation from 8010293: Finally, the sandwich line with the horn is placed on the ground, for the horn to be inspected and, if needed, exchanged for a new one. The whole procedure was trained with several members of the AA team, for quick and safe handling, and to share the radiation dose amongst them.

  18. Non-communicating Rudimentary Uterine Horn Pregnancy

    Directory of Open Access Journals (Sweden)

    I Upadhyaya

    2011-12-01

    Full Text Available Pregnancy in a non-communicating rudimentary horn is an extremely rare form of ectopic gestation. The rudimentary horn may or may not communicate with the uterine cavity with the majority of cases being non-communicating. The patient exhibits features of acute abdomen and carries a high risk of maternal death. Even modern scans remain elusive whereas laparatomy remains the confi rmatory procedure for the diagnosis. Because of the varied muscular constitution in the thickness and distensibility of the wall of the rudimentary horn, pregnancy is accommodated for a variable period of gestation. Here, we report three cases of pregnancy in a non-communicating rudimentary horn of the uterus in different periods of gestation, their outcome and a review of the available literature. Keywords: Mullerian anomalies, non-communicating rudimentary horn pregnancy, surgical management.

  19. Upregulation of adrenomedullin in the spinal cord and dorsal root ganglia in the early phase of CFA-induced inflammation in rats.

    Science.gov (United States)

    Hong, Yanguo; Liu, Yushan; Chabot, Jean-Guy; Fournier, Alain; Quirion, Rémi

    2009-11-01

    Adrenomedullin (AM), a member of calcitonin gene-related peptide (CGRP) family, has been demonstrated to be a pronociceptive mediator [28]. This study was undertaken to investigate the role of AM in a model of complete Freund's adjuvant (CFA)-induced inflammatory pain. Injection of CFA, but not of saline, in the unilateral hindpaw produced an increase in the expression of AM-like immunoreactivity (AM-IR) in laminae I-II of the spinal cord as well as in small- and medium-sized dorsal root ganglion (DRG) neurons at 48 h. The content of AM in DRG on the side ipsilateral to CFA injection started to increase at 4 h and remained at high levels at 24 and 48 h. The selective antagonist of AM receptors, AM(22-52), administered intrathecally (i.t.) 24 h after CFA injection inhibited inflammation-associated hyperalgesia in a dose-dependent manner (2, 5 and 10 nmol). Impressively, this anti-hyperalgesic effect lasted for at least 24 h. I.t. administration of AM(22-52) (10 nmol) also reversed CFA-induced increase in AM-IR in the spinal dorsal horn and DRG. Furthermore, blockade of AM receptors abolished CFA-induced changes in the expression and content of CGRP-like immunoreactivity in these regions. Taken together, our results suggest that the upregulation of AM in DRG neurons contributes to the development of inflammatory pain, and this effect is mediated, at least in part, by enhancing the expression and release of CGRP. Blocking AM receptor downstream signaling effects using antagonists has the potential of relieving pain following the induction of inflammation.

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

    Science.gov (United States)

    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

  1. Horn growth patterns in Alpine chamois.

    Science.gov (United States)

    Corlatti, Luca; Gugiatti, Alessandro; Imperio, Simona

    2015-06-01

    The analysis of horn growth may provide important information about the allocation of metabolic resources to secondary sexual traits. Depending on the selective advantages offered by horn size during intra- and inter-specific interactions, ungulates may show different investment in horn development, and growth variations within species may be influenced by several parameters, such as sex, age, or resource availability. We investigated the horn growth patterns in two hunted populations of Alpine chamois (Rupicapra r. rupicapra) in the Central Italian Alps. We tested the role of individual heterogeneity on the growth pattern and explored the variation in annulus length as a function of different factors (sex, age, hunting location, cohort). We then investigated the mechanisms underlying horn growth trajectories to test for the occurrence of compensatory or recovery growth and their potential differences between sexes and populations. Annulus length varied as a function of sex, age of individuals and, marginally, hunting location; no effect of cohort or individual heterogeneity was detected. Male and female chamois showed compensatory horn growth within the first 5½ years of life, though the partial convergence of horn trajectories in chamois suggests that this mechanisms would best be described as 'recovery growth'. Compensation rates were greater in males than in females, while only compensatory growth rates up to 2½ years of age were different in the two populations. Besides confirming the sex- and age-dependent pattern of horn development, our study suggests that the mechanism of recovery growth supports the hypothesis of horn size as a weakly selected sexual trait in male and female chamois. Furthermore, the greater compensation rates in horn growth shown by male chamois possibly suggest selective effects of hunting on age at first reproduction, while different compensation rates between populations may suggest the occurrence of some plasticity in resource

  2. Horn of Africa food crisis

    CERN Multimedia

    Staff Association

    2011-01-01

    YOU ARE WONDERFUL, THANK YOU! As we have indicated previously, the Horn of Africa is experiencing an extremely severe food crisis as a result of one of the toughest droughts since the early 1950s. A total of over 12 million people in Djibouti, Ethiopia, Somalia, Kenya and Uganda are severely affected by this devastating crisis and the UN has officially declared famine in these regions. In addition, children are the most vulnerable victims, with more than half a million children at risk of imminent death from severe malnutrition and an estimated 2.3 million children already malnourished. At the beginning of August we opened an account to receive your donations. We are pleased to announce that the funds received are 30’500 CHF, the total sum of which will be transferred to UNICEF. We would like to thank all those who have contributed to this important cause. Rolf Heuer Director-General Michel Goossens President of the Staff Association

  3. 12MW Horns Rev experiment

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Peña, A.; Mikkelsen, Torben

    The 12MW project with the full title ‘12 MW wind turbines: the scientific basis for their operation at 70 to 270 m height offshore’ has the goal to experimentally investigate the wind and turbulence characteristics between 70 and 270 m above sea level and thereby establish the scientific basis...... relevant for the next generation of huge 12 MW wind turbines operating offshore. The report describes the experimental campaign at the Horns Rev offshore wind farm at which observations from Doppler Laser LIDAR and SODAR were collected from 3 May to 24 October 2006. The challenges for mounting...... profile. Further studies on this part of the work are on-going. Technical detail on LIDAR and SODAR are provided as well as theoretical work on turbulence and atmospheric boundary layer flow. Selected results from the experimental campaign are reported....

  4. Convergence of meningeal and facial afferents onto trigeminal brainstem neurons: an electrophysiological study in rat and man.

    Science.gov (United States)

    Ellrich, J; Andersen, O K; Messlinger, K; Arendt-Nielsen, L

    1999-09-01

    Headache is often accompanied by referred pain in the face. This phenomenon is probably due to a convergence of afferent inputs from the meninges and the face onto central trigeminal neurons within the medullary dorsal horn (MDH). The possible existence and extent of this convergence was examined in rat and man. MDH neurons activated by stimulation of the parietal meninges were tested for convergent tactile and noxious mechanical input from all three facial branches of the trigeminal nerve. All 21 units with meningeal input could also be activated by facial stimuli. Brush stimuli applied to the supraorbital nerve area activated 86%, to the infraorbital nerve area 29%, and to the mental nerve area none of the units. Pinch stimuli applied to the supraorbital nerve area activated 95%, to the infraorbital nerve area 86%, and to the mental nerve area 52% of the units. The results suggest convergence of meningeal and facial inputs concentrated on the supraorbital nerve in rat. In man convergence was examined by probing neuronal excitability of MDH applying the blink reflex (BR) during Valsalva maneuver which probably increases intracranial pressure. The BR evoked by supraorbital nerve stimulation remained unchanged, while the BR evoked by mental nerve stimulation was significantly facilitated. This facilitation may be due to convergence of meningeal and facial inputs onto trigeminal neurons in man.

  5. 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.

  6. The SeaHorn Verification Framework

    Science.gov (United States)

    Gurfinkel, Arie; Kahsai, Temesghen; Komuravelli, Anvesh; Navas, Jorge A.

    2015-01-01

    In this paper, we present SeaHorn, a software verification framework. The key distinguishing feature of SeaHorn is its modular design that separates the concerns of the syntax of the programming language, its operational semantics, and the verification semantics. SeaHorn encompasses several novelties: it (a) encodes verification conditions using an efficient yet precise inter-procedural technique, (b) provides flexibility in the verification semantics to allow different levels of precision, (c) leverages the state-of-the-art in software model checking and abstract interpretation for verification, and (d) uses Horn-clauses as an intermediate language to represent verification conditions which simplifies interfacing with multiple verification tools based on Horn-clauses. SeaHorn provides users with a powerful verification tool and researchers with an extensible and customizable framework for experimenting with new software verification techniques. The effectiveness and scalability of SeaHorn are demonstrated by an extensive experimental evaluation using benchmarks from SV-COMP 2015 and real avionics code.

  7. 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.

  8. AA, sandwich line with magnetic horn

    CERN Document Server

    CERN PhotoLab

    1980-01-01

    The magnetic horn, focusing the antiprotons emanating from the target, was affixed to a sandwich line through which the 150 kA pulses were supplied. Expecting to have to change from time to time the fragile horn (inner conductor only 0.7 mm thick), the assembly was designed for quick exchange. At the lower end of the sandwich line we see the connectors for the high-current cables, at the upper end the magnet horn. It has just been lifted from the V-supports which held it aligned downstream of the target. Continue with 8010293.

  9. An Annotated Guide and Interactive Database for Solo Horn Repertoire

    Science.gov (United States)

    Schouten, Sarah

    2012-01-01

    Given the horn's lengthy history, it is not surprising that many scholars have examined the evolution of the instrument from the natural horn to the modern horn and its expansive repertoire. Numerous dissertations, theses, and treatises illuminate specific elements of the horn's solo repertoire; however, no scholar has produced a…

  10. Neutrophilic dermatosis of dorsal hands

    Directory of Open Access Journals (Sweden)

    S Kaur

    2015-01-01

    Full Text Available Sweet′s syndrome is characterized by erythematous tender nodules and plaques over face and extremities. Fever, leukocytosis with neutrophilia, and a neutrophilic infiltrate in the dermis are characteristic features. Neutrophilic dermatosis of dorsal hands is a rare localized variant of Sweet′s syndrome occurring predominantly over dorsa of hands. Various degrees of vascular damage may be observed on histopathology of these lesions. Both Sweet′s syndrome and its dorsal hand variant have been reported in association with malignancies, inflammatory bowel diseases, and drugs. We report a patient with neutrophilic dermatoses of dorsal hands associated with erythema nodosum. He showed an excellent response to corticosteroids and dapsone.

  11. Shape representations in the primate dorsal visual stream

    Directory of Open Access Journals (Sweden)

    Tom eTheys

    2015-04-01

    Full Text Available The primate visual system extracts object shape information for object recognition in the ventral visual stream. Recent research has demonstrated that object shape is also processed in the dorsal visual stream, which is specialized for spatial vision and the planning of actions. A number of studies have investigated the coding of 2D shape in the anterior intraparietal area (AIP, one of the end-stage areas of the dorsal stream which has been implicated in the extraction of affordances for the purpose of grasping. These findings challenge the current understanding of area AIP as a critical stage in the dorsal stream for the extraction of object affordances. The representation of three-dimensional (3D shape has been studied in two interconnected areas known to be critical for object grasping: area AIP and area F5a in the ventral premotor cortex (PMv, to which AIP projects. In both areas neurons respond selectively to 3D shape defined by binocular disparity, but the latency of the neural selectivity is approximately 10 ms longer in F5a compared to AIP, consistent with its higher position in the hierarchy of cortical areas. Furthermore F5a neurons were more sensitive to small amplitudes of 3D curvature and could detect subtle differences in 3D structure more reliably than AIP neurons. In both areas, 3D-shape selective neurons were co-localized with neurons showing motor-related activity during object grasping in the dark, indicating a close convergence of visual and motor information on the same clusters of neurons.

  12. Next steps in propositional horn contraction

    CSIR Research Space (South Africa)

    Booth, R

    2009-06-01

    Full Text Available not opted for this choice.) Our start- ing point for defining Horn e-contraction is in terms of Del- grande’s definition of e-remainder sets. Definition 3.1 (Horn e-Remainder Sets) For a belief setH , X ∈ H ↓e Φ iff (i) X ⊆ H , (ii) X 6|= Φ, and (iii...) for every X ′ s.t. X ⊂ X ′ ⊆ H , X ′ |= Φ. We refer to the elements of H ↓eΦ as the Horn e-remainder sets of H w.r.t. Φ. It is easy to verify that all Horn e-remainder sets are belief sets. Also, H ↓eΦ = ∅ iff |= Φ. We now proceed to define selection...

  13. Pediatric Periocular Keratin Horns: A Case Series.

    Science.gov (United States)

    Sachdev, Amun; Shafi, Fariha; Mehta, Purnima; Ahluwalia, Harpreet

    There are very few published cases of periocular keratin horns that have been reported in children. This study reports 2 pediatric cases of periocular keratin horns. The authors describe a 7-year-old male child who developed a keratin horn on the right lower eyelid and a 16-year-old female who developed a caruncular keratin horn. Both cases underwent excision biopsy, and subsequent histology confirmed that there was no evidence of malignancy. However, on the basis of the current evidence in adults and the difficulty in drawing firm conclusions from the small number of reported pediatric cases, the authors suggest that these lesions should be carefully managed due to the possibility of premalignant or malignant change at the base of the lesion.

  14. Assembly of the magnetic horns under way

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Ahmed Cherif of the EST Division's Metrology Service checks the straightness of the inner conductor of the first magnetic horn for CNGS. The tolerance is less than one millimetre over a length of approximately 6.5 metres.

  15. Follicular infundibulum tumour presenting as cutaneous horn

    Directory of Open Access Journals (Sweden)

    Jayaraman M

    1996-01-01

    Full Text Available Tumour of follicular infundibulum is an organoid tumour with a plate like growth attached to the epidermis with connection from the follicular epithelium. We are reporting such a case unusually presenting as cutaneous horn.

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

    Science.gov (United States)

    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.

  17. Dcc regulates asymmetric outgrowth of forebrain neurons in zebrafish.

    Directory of Open Access Journals (Sweden)

    Jingxia Gao

    Full Text Available The guidance receptor DCC (deleted in colorectal cancer ortholog UNC-40 regulates neuronal asymmetry development in Caenorhabditis elegans, but it is not known whether DCC plays a role in the specification of neuronal polarity in vertebrates. To examine the roles of DCC in neuronal asymmetry regulation in vertebrates, we studied zebrafish anterior dorsal telencephalon (ADt neuronal axons. We generated transgenic zebrafish animals expressing the photo-convertible fluorescent protein Kaede in ADt neurons and then photo-converted Kaede to label specifically the ADt neuron axons. We found that ADt axons normally project ventrally. Knock down of Dcc function by injecting antisense morpholino oligonucleotides caused the ADt neurons to project axons dorsally. To examine the axon projection pattern of individual ADt neurons, we labeled single ADt neurons using a forebrain-specific promoter to drive fluorescent protein expression. We found that individual ADt neurons projected axons dorsally or formed multiple processes after morpholino knock down of Dcc function. We further found that knock down of the Dcc ligand, Netrin1, also caused ADt neurons to project axons dorsally. Knockdown of Neogenin1, a guidance receptor closely related to Dcc, enhanced the formation of aberrant dorsal axons in embryos injected with Dcc morpholino. These experiments provide the first evidence that Dcc regulates polarized axon initiation and asymmetric outgrowth of forebrain neurons in vertebrates.

  18. Horn of Africa food crisis

    CERN Multimedia

    Association du personnel

    2011-01-01

    Dear colleagues, As many of you are already aware, the Horn of Africa is experiencing an extremely severe food crisis as a result of one of the toughest droughts since the early 1950s. A total of over 12 million people in Djibouti, Ethiopia, Somalia, Kenya and Uganda are severely affected by this devastating crisis and the UN has officially declared famine in these regions. In addition, children are the most vulnerable victims, with more than a half million children at risk of imminent death from severe malnutrition and an estimated 2.3 million children already malnourished. An immediate, determined mobilization is required in order to avert an imminent humanitarian catastrophe and to prevent millions of people from being robbed of a future through the scourge of hunger and malnutrition. CERN has decided to join this international mobilization by specifically opening an account for those who want to make a donation to help the drought- and famine-affected populations in the region. Children being the first...

  19. Solving non-linear Horn clauses using a linear Horn clause solver

    DEFF Research Database (Denmark)

    Kafle, Bishoksan; Gallagher, John Patrick; Ganty, Pierre

    2016-01-01

    In this paper we show that checking satisfiability of a set of non-linear Horn clauses (also called a non-linear Horn clause program) can be achieved using a solver for linear Horn clauses. We achieve this by interleaving a program transformation with a satisfiability checker for linear Horn...... clauses (also called a solver for linear Horn clauses). The program transformation is based on the notion of tree dimension, which we apply to a set of non-linear clauses, yielding a set whose derivation trees have bounded dimension. Such a set of clauses can be linearised. The main algorithm...... dimension. We constructed a prototype implementation of this approach and performed some experiments on a set of verification problems, which shows some promise....

  20. 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...

  1. The rams horn in western history

    Science.gov (United States)

    Lubman, David

    2003-10-01

    The shofar or rams horn-one of the most ancient of surviving aerophones-may have originated with early Neolithic herders. The shofar is mentioned frequently and importantly in the Hebrew bible and in later biblical and post-biblical literature. Despite its long history, contemporary ritual uses, and profound symbolic significance to western religion, no documentation of shofar acoustical properties was found. Since ancient times, shepherds of many cultures have fashioned sound instruments from the horns of herd animals for practical and musical uses. Shepherd horns of other cultures exhibit an evolution of form and technology (e.g., the inclusion of finger holes). The shofar is unique in having retained its primitive form. It is suggested that after centuries of practical use, the shofar became emblematic of the shepherd culture. Ritual use then developed, which froze its form. A modern ritual rams horn played by an experienced blower was examined. This rather short horn was determined to have a source strength of 92 dB (A) at 1 m, a fundamental frequency near 420 Hz, and maximum power output between 1.2 and 1.8 kHz. Sample sounds and detection range estimates are provided.

  2. Repetitive Diving in Trained Rats Still Increases Fos Production in Brainstem Neurons after Bilateral Sectioning of the Anterior Ethmoidal Nerve

    Directory of Open Access Journals (Sweden)

    Paul F Mcculloch

    2016-04-01

    Full Text Available This research was designed to investigate the role of the anterior ethmoidal nerve (AEN during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N=24 were trained to swim and dive through a 5 m underwater maze. Some rats (N=12 had bilateral sectioning of the AEN, others a Sham surgery (N=12. Twelve rats (6 AEN cut and 6 Sham had 24 post-surgical dive trials over 2 hrs to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kölliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus the AENs are not required for initiation of the diving response. Other nerve(s that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response.

  3. Little Big Horn River Water Quality Project

    Energy Technology Data Exchange (ETDEWEB)

    Bad Bear, D.J.; Hooker, D. [Little Big Horn Coll., Crow Agency, MT (United States)

    1995-10-01

    This report summarizes the accomplishments of the Water Quality Project on the Little Big horn River during the summer of 1995. The majority of the summer was spent collecting data on the Little Big Horn River, then testing the water samples for a number of different tests which was done at the Little Big Horn College in Crow Agency, Montana. The intention of this study is to preform stream quality analysis to gain an understanding of the quality of selected portion of the river, to assess any impact that the existing developments may be causing to the environment and to gather base-line data which will serve to provide information concerning the proposed development. Citizens of the reservation have expressed a concern of the quality of the water on the reservation; surface waters, ground water, and well waters.

  4. RARE PRESENTATION OF RUPTURED RUDIMENTARY HORN PREGNANCY

    Directory of Open Access Journals (Sweden)

    Shergill Harbhajan K, Grover Suparna, Chhabra Ajay

    2015-10-01

    Full Text Available It is a rare occurrence for the rudimentary horn of uterus to harbour a pregnancy and the usual outcome is devastating leading to a spontaneous rupture in second trimester with the patient presenting in shock with massive intra-peritoneal haemorrhage and if appropriate management is not instituted in time it may lead to high rate of mortality. We report an unusual case of rupture rudimentary horn pregnancy who presented as a chronic ectopic with an adnexal mass and surprisingly with no sign of shock. Diagnosis is often difficult in such a situation which puts the treating gynaecologist in dilemma. High clinical suspicion supplemented with radiological findings helped clinch the diagnosis and laparotomy was performed followed by resection of the rudimentary horn to prevent future complications.

  5. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    of large dorsal root ganglion cells. Motor conduction studies, autonomic function and warm and cold temperature sensation remained unchanged at all doses of cisplatin treatment. The results of these studies are consistent with degeneration of large sensory neurons whereas there was no evidence of distal...

  6. Constraint specialisation in Horn clause verification

    DEFF Research Database (Denmark)

    Kafle, Bishoksan; Gallagher, John Patrick

    2017-01-01

    We present a method for specialising the constraints in constrained Horn clauses with respect to a goal. We use abstract interpretation to compute a model of a query–answer transformed version of a given set of clauses and a goal. The constraints from the model are then used to compute...... underlying the clauses. Experimental results on verification problems show that this is an effective transformation, both in our own verification tools (based on a convex polyhedra analyser) and as a pre-processor to other Horn clause verification tools....

  7. AA, Inner Conductor of Magnetic Horn

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    Antiprotons emerging at large angles from the production target (hit by an intense 26 GeV proton beam from the PS), were focused into the acceptance of the injection line of the AA by means of a "magnetic horn" (current-sheet lens). Here we see an early protype of the horn's inner conductor, machined from solid aluminium to a thickness of less than 1 mm. The 1st version had to withstand pulses of 150 kA, 15 us long, every 2.4 s. See 8801040 for a later version.

  8. Ectopic pregnancy in non communicating rudimentary horn of uterus

    International Nuclear Information System (INIS)

    Khan, A.; Soomro, N.

    2001-01-01

    Rudimentary horn ectopic pregnancy occurs very infrequently in gynecological practice. A case of rudimentary horn ectopic pregnancy, managed with salvage of the patient, is presented here in this report. (author)

  9. Human dorsal root ganglion in vivo morphometry and perfusion in Fabry painful neuropathy.

    Science.gov (United States)

    Godel, Tim; Bäumer, Philipp; Pham, Mirko; Köhn, Anja; Muschol, Nicole; Kronlage, Moritz; Kollmer, Jennifer; Heiland, Sabine; Bendszus, Martin; Mautner, Victor-Felix

    2017-09-19

    To evaluate functional and morphometric magnetic resonance neurography of the dorsal root ganglion and peripheral nerve segments in patients with Fabry painful neuropathy. In this prospective study, the lumbosacral dorsal root ganglia and proximal peripheral nerve segments of the lower extremity were examined in 11 male patients with Fabry disease by a standardized 3T magnetic resonance neurography protocol. Volumes of L3 to S2 dorsal root ganglia, perfusion parameters of L5-S1 dorsal root ganglia and the spinal nerve L5, and the cross-sectional area of the proximal sciatic nerve were compared to healthy controls. Dorsal root ganglia of patients with Fabry disease were symmetrically enlarged by 78% (L3), 94% (L4), 122% (L5), 115% (S1), and 119% (S2) ( p Fabry disease and controls ( p = 0.7). The sciatic nerve of patients with Fabry disease at the thigh level showed an increase in cross-sectional area by 48% ( p Fabry disease have severely enlarged dorsal root ganglia with dysfunctional perfusion. This may be due to glycolipid accumulation in the dorsal root ganglia mediating direct neurotoxic effects and decreased neuronal blood supply. These alterations were less pronounced in peripheral nerve segments. Thus, the dorsal root ganglion might play a key pathophysiologic role in the development of neuropathy and pain in Fabry disease. © 2017 American Academy of Neurology.

  10. Horn's Biologically Active Substances - Can We Replace Horns of Critically Endangered Species (Saiga) by Horns of More Abundant Animals?

    Czech Academy of Sciences Publication Activity Database

    Mikšík, Ivan; Romanov, O.

    2017-01-01

    Roč. 7, č. 1 (2017), s. 3-11 ISSN 2210-3155 R&D Projects: GA ČR(CZ) GA15-01948S Institutional support: RVO:67985823 Keywords : biologically active compounds * horn * rhinoceros * saiga * traditional Chinese medicine Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry

  11. Functional genomics of the horn fly, Haematobia irritans (Linnaeus, 1758)

    OpenAIRE

    Torres, Lorena; Almazán, Consuelo; Ayllón, Nieves; Galindo, Ruth C; Rosario-Cruz, Rodrigo; Quiroz-Romero, Héctor; de la Fuente, José

    2011-01-01

    Abstract Background The horn fly, Haematobia irritans (Linnaeus, 1758) (Diptera: Muscidae) is one of the most important ectoparasites of pastured cattle. Horn flies infestations reduce cattle weight gain and milk production. Additionally, horn flies are mechanical vectors of different pathogens that cause disease in cattle. The aim of this study was to conduct a functional genomics study in female horn flies using Expressed Sequence Tags (EST) analysis and RNA interference (RNAi). Results A c...

  12. Computed tomography of the temporal horns at Alzheimer's disease

    International Nuclear Information System (INIS)

    Gerber, U.; Vogel

    1989-01-01

    In the literature there are different opinions referring to the involvement of the temporal lobes or horns at Alzheimer's disease. Conventionally computed tomogram of the head does not include the temporal horn in its full length. A simple method to demonstrate the temporal horns after cranial computer tomography is described. It allows the evaluation of temporal lobe and temporal horn if questionable alterations at Alzheimer's disease are to be discussed. (orig.) [de

  13. Squamous cell carcinoma presenting as cutaneous horn in diabetic ...

    African Journals Online (AJOL)

    ... not the horn itself, which is just dead keratin, but rather the nature of the underlying disease, although the horns are usually benign and that's why the case is reported. Keywords: Cutaneous horn; Cornu cutaneum; Squamous Cell Carcinoma; Diabetes Mellitus. Sudanese Journal of Dermatology Vol. 4 (2) 2006: pp. 86-91 ...

  14. A case of rudimentary horn pregnancy diagnosed after failed ...

    African Journals Online (AJOL)

    2016-04-26

    Apr 26, 2016 ... horn does not communicate with the uterus; in “class IIc” the rudimentary horn does not have a cavity, ... the endometrium in the rudimentary horn is rarely functional and is not always synchronous with the ... scan, a useful radiologic tool in the diagnosis and planning of surgical treatment in uncertain cases.

  15. Contribution of amygdala CRF neurons to chronic pain.

    Science.gov (United States)

    Andreoli, Matthew; Marketkar, Tanvi; Dimitrov, Eugene

    2017-12-01

    We investigated the role of amygdala corticotropin-releasing factor (CRF) neurons in the perturbations of descending pain inhibition caused by neuropathic pain. Forced swim increased the tail-flick response latency in uninjured mice, a phenomenon known as stress-induced analgesia (SIA) but did not change the tail-flick response latency in mice with neuropathic pain caused by sciatic nerve constriction. Neuropathic pain also increased the expression of CRF in the central amygdala (CeAmy) and ΔFosB in the dorsal horn of the spinal cord. Next, we injected the CeAmy of CRF-cre mice with cre activated AAV-DREADD (Designer Receptors Exclusively Activated by Designer Drugs) vectors. Activation of CRF neurons by DREADD/Gq did not affect the impaired SIA but inhibition of CRF neurons by DREADD/Gi restored SIA and decreased allodynia in mice with neuropathic pain. The possible downstream circuitry involved in the regulation of SIA was investigated by combined injections of retrograde cre-virus (CAV2-cre) into the locus ceruleus (LC) and cre activated AAV-diphtheria toxin (AAV-FLEX-DTX) virus into the CeAmy. The viral injections were followed by a sciatic nerve constriction ipsilateral or contralateral to the injections. Ablation of amygdala projections to the LC on the side of injury but not on the opposite side, completely restored SIA, decreased allodynia and decreased ΔFosB expression in the spinal cord in mice with neuropathic pain. The possible lateralization of SIA impairment to the side of injury was confirmed by an experiment in which unilateral inhibition of the LC decreased SIA even in uninjured mice. The current view in the field of pain research attributes the process of pain chronification to abnormal functioning of descending pain inhibition. Our results demonstrate that the continuous activity of CRF neurons brought about by persistent pain leads to impaired SIA, which is a symptom of dysregulation of descending pain inhibition. Therefore, an over

  16. Gemelligraviditet i et horn af bicorn uterus

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Langhoff-Roos, Jens

    2009-01-01

    Bicornuate uterus is associated with early foetal loss and extremely preterm delivery. A patient with dichorionic twins in a single horn of a bicornuate uterus was admitted in week 24 + 6 with preterm labour. Long-term treatment with a combination of tocolytics, atosiban and diclofenac inhibited...

  17. TERRITORIAL BEHAVIOUR IN CERTAIN HORNED UNGULATES ...

    African Journals Online (AJOL)

    TERRITORIAL BEHAVIOUR IN CERTAIN HORNED UNGULATES, WITH SPECIAL. REFERENCE TO THE EXAMPLES OF THOMSON'S AND GRANT'S GAZELLES. FRITZ R. WALTHER. Department of Wildlife and Fisheries Sciences, Texas A & M University,. College Station, Texas 77843. ABSTRACT. An attempt has been ...

  18. Population dynamics of Prostephanus truncatus (Horn) and ...

    African Journals Online (AJOL)

    The effects of three maize varieties and two storage seasons on the population dynamics of Prostephanus truncates (Horn) and Sitophilus zeamais Motschulsky were observed in the traditional `Ewe' barn in the field. Two local varieties, Dzolokpuita and Abutia and an improved variety, Abeleehi, were stored with the husk on ...

  19. The orthopaedic management of myelomeningocele | Horn | South ...

    African Journals Online (AJOL)

    The orthopaedic management of myelomeningocele. A Horn, S Dix-Peek, S Mears, EB Hoffman. Abstract. Despite improvement in antenatal care and screening, myelomeningocele remains the most common congenital birth defect, with a reported incidence of 1 - 2.5/1000 patients in the Western Cape, South Africa.

  20. Assembly of the magnetic horns under way

    CERN Multimedia

    2003-01-01

    One of the key components of the CNGS facility is the system of magnetic lenses, known as horns, which are to point the pions and kaons that will decay into muons and muon-neutrinos in the direction of the Gran Sasso Laboratory. Positioned at the end of the target, which produces the pions and kaons, the system comprises two of these horns. The first focuses the positively charged pions and kaons, which have an energy of approximately 35 GeV, and defocuses the negative particles. Unfortunately, it has a tendency to cause excessive deflection of particles that have energies of less than 35 GeV and insufficient deflection of those with energies of more than 35 GeV. These negative effects are corrected by the second horn (also known as the reflector), which is positioned 40 metres from the first. Ahmed Cherif of the EST Division's Metrology Service checks the straightness of the inner conductor of the first magnetic horn for CNGS. The tolerance is less than one millimetre over a length of approximately 6.5 metre...

  1. Loss of Ca(2+)-permeable AMPA receptors in synapses of tonic firing substantia gelatinosa neurons in the chronic constriction injury model of neuropathic pain.

    Science.gov (United States)

    Chen, Yishen; Derkach, Victor A; Smith, Peter A

    2016-05-01

    Synapses transmitting nociceptive information in the spinal dorsal horn undergo enduring changes following peripheral nerve injury. Indeed, such injury alters the expression of the GluA2 subunit of glutamatergic AMPA receptors (AMPARs) in the substantia gelatinosa and this predicts altered channel conductance and calcium permeability, leading to an altered function of excitatory synapses. We therefore investigated the functional properties of synaptic AMPA receptors in rat substantia gelatinosa neurons following 10-20d chronic constriction injury (CCI) of the sciatic nerve; a model of neuropathic pain. We measured their single-channel conductance and sensitivity to a blocker of calcium permeable AMPA receptors (CP-AMPARs), IEM1460 (50μM). In putative inhibitory, tonic firing neurons, CCI reduced the average single-channel conductance of synaptic AMPAR from 14.4±3.5pS (n=12) to 9.2±1.0pS (n=10, pinjury acting at synapses of inhibitory neurons to reduce their drive and therefore inhibitory tone in the spinal cord, therefore contributing to the central sensitization associated with neuropathic pain. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Whole transcriptome expression of trigeminal ganglia compared to dorsal root ganglia in Rattus Norvegicus

    DEFF Research Database (Denmark)

    Kogelman, Lisette Johanna Antonia; Christensen, Rikke Elgaard; Pedersen, Sara Hougaard

    2017-01-01

    The trigeminal ganglia (TG) subserving the head and the dorsal root ganglia (DRG) subserving the rest of the body are homologous handling sensory neurons. Differences exist, as a number of signaling substances cause headache but no pain in the rest of the body. To date, very few genes involved in...

  3. Up-regulation of Robo1 in dorsal root ganglia after sciatic nerve ...

    African Journals Online (AJOL)

    Yomi

    2012-01-05

    Jan 5, 2012 ... post-SNT. Neither normal, nor SNT DRG exhibited co-localization of Robo1 and 2, and this observation was independent of neuron diameter. These results suggest that Robo1 in DRG is upregulated following sciatic nerve transection in rats. Key words: Dorsal root ganglion, rat, roundabout 1, sciatic nerve ...

  4. Reward Processing by the Dorsal Raphe Nucleus: 5-HT and Beyond

    Science.gov (United States)

    Luo, Minmin; Zhou, Jingfeng; Liu, Zhixiang

    2015-01-01

    The dorsal raphe nucleus (DRN) represents one of the most sensitive reward sites in the brain. However, the exact relationship between DRN neuronal activity and reward signaling has been elusive. In this review, we will summarize anatomical, pharmacological, optogenetics, and electrophysiological studies on the functions and circuit mechanisms of…

  5. Neuronal CC chemokines : the distinct roles of CCL21 and CCL2 in neuropathic pain

    NARCIS (Netherlands)

    Biber, Knut; Boddeke, Erik

    2014-01-01

    The development of neuropathic pain in response to peripheral nerve lesion for a large part depends on microglia located at the dorsal horn of the spinal cord. Thus the injured nerve initiates a response of microglia, which represents the start of a cascade of events that leads to neuropathic pain

  6. Constraint Specialisation in Horn Clause Verification

    DEFF Research Database (Denmark)

    Kafle, Bishoksan; Gallagher, John Patrick

    2015-01-01

    -down and propagate answer constraints bottom-up. Our approach does not unfold the clauses at all; we use the constraints from the model to compute a specialised version of each clause in the program. The approach is independent of the abstract domain and the constraints theory underlying the clauses. Experimental......We present a method for specialising the constraints in constrained Horn clauses with respect to a goal. We use abstract interpretation to compute a model of a query-answer transformation of a given set of clauses and a goal. The effect is to propagate the constraints from the goal top...... results on verification problems show that this is an effective transformation, both in our own verification tools (convex polyhedra analyser) and as a pre-processor to other Horn clause verification tools....

  7. Ultrasonic horn design for ultrasonic machining technologies

    Directory of Open Access Journals (Sweden)

    Naď M.

    2010-07-01

    Full Text Available Many of industrial applications and production technologies are based on the application of ultrasound. In many cases, the phenomenon of ultrasound is also applied in technological processes of the machining of materials. The main element of equipments that use the effects of ultrasound for machining technology is the ultrasonic horn – so called sonotrode. The performance of ultrasonic equipment, respectively ultrasonic machining technologies depends on properly designed of sonotrode shape. The dynamical properties of different geometrical shapes of ultrasonic horns are presented in this paper. Dependence of fundamental modal properties (natural frequencies, mode shapes of various sonotrode shapes for various geometrical parameters is analyzed. Modal analyses of the models are determined by the numerical simulation using finite element method (FEM design procedures. The mutual comparisons of the comparable parameters of the various sonotrode shapes are presented.

  8. AA, inner conductor of a magnetic horn

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    At the start-up of the AA and during its initial operation, magnetic horns focused the antiprotons emanating from the production target. These "current-sheet lenses" had a thin inner conductor (for minimum absorption of antiprotons), machined from aluminium to wall thicknesses of 0.7 or 1 mm. The half-sine pulses rose to 150 kA in 8 microsec. The angular acceptance was 50 mrad.

  9. Functional genomics of the horn fly, Haematobia irritans (Linnaeus, 1758).

    Science.gov (United States)

    Torres, Lorena; Almazán, Consuelo; Ayllón, Nieves; Galindo, Ruth C; Rosario-Cruz, Rodrigo; Quiroz-Romero, Héctor; de la Fuente, José

    2011-02-10

    The horn fly, Haematobia irritans (Linnaeus, 1758) (Diptera: Muscidae) is one of the most important ectoparasites of pastured cattle. Horn flies infestations reduce cattle weight gain and milk production. Additionally, horn flies are mechanical vectors of different pathogens that cause disease in cattle. The aim of this study was to conduct a functional genomics study in female horn flies using Expressed Sequence Tags (EST) analysis and RNA interference (RNAi). A cDNA library was made from whole abdominal tissues collected from partially fed adult female horn flies. High quality horn fly ESTs (2,160) were sequenced and assembled into 992 unigenes (178 contigs and 814 singlets) representing molecular functions such as serine proteases, cell metabolism, mitochondrial function, transcription and translation, transport, chromatin structure, vitellogenesis, cytoskeleton, DNA replication, cell response to stress and infection, cell proliferation and cell-cell interactions, intracellular trafficking and secretion, and development. Functional analyses were conducted using RNAi for the first time in horn flies. Gene knockdown by RNAi resulted in higher horn fly mortality (protease inhibitor functional group), reduced oviposition (vitellogenin, ferritin and vATPase groups) or both (immune response and 5'-NUC groups) when compared to controls. Silencing of ubiquitination ESTs did not affect horn fly mortality and oviposition while gene knockdown in the ferritin and vATPse functional groups reduced mortality when compared to controls. These results advanced the molecular characterization of this important ectoparasite and suggested candidate protective antigens for the development of vaccines for the control of horn fly infestations.

  10. Actively adjustable step-type ultrasonic horns in longitudinal vibration

    Science.gov (United States)

    Lin, Shuyu; Guo, Hao; Xu, Jie

    2018-04-01

    Actively adjustable longitudinal step-type ultrasonic horns are proposed and studied. The horn is composed of a traditional ultrasonic horn and piezoelectric material. In practical applications, this kind of step-type ultrasonic horn is mechanically excited by an ultrasonic transducer and the piezoelectric material is connected to an adjustable electric impedance. In this research, the effects of the electric impedance and of the location of the piezoelectric material on the performance of the horn are studied. It is shown that when the electric resistance is increased, the resonance frequency of the horn is increased; the displacement magnification is increased when the piezoelectric material is located in the large end and decreased when the piezoelectric material is located in the small end of the horn. The displacement magnification for the piezoelectric material in the large end is larger than that for the piezoelectric material in the small end of the horn. Some step-type ultrasonic horns are designed and manufactured; the resonance frequency and the displacement magnification are measured by means of POLYTEC Laser Scanning vibrometer. It is shown that the theoretical resonance frequency and the displacement magnification are in good agreement with the measured results. It is concluded that by means of the insertion of the piezoelectric material in the longitudinal horn, the horn performance can be adjusted by changing the electric impedance and the location of the piezoelectric material in the horn. It is expected that this kind of adjustable ultrasonic horns can be used in traditional and potential ultrasonic technologies where the vibrational performance adjustment is needed.

  11. LS1 Report: Thank you magnetic horn!

    CERN Multimedia

    Antonella Del Rosso & Katarina Anthony

    2014-01-01

    Experiments at the Antimatter Decelerator (AD) have been receiving beams since the beginning of this week. There is a crucial element at the heart of the chain that prepares the antiproton beam: the so-called magnetic horn, a delicate piece of equipment that had to be refurbished during LS1 and that is now showing just how well it can perform.   View from the top of the target and horn trolley, along the direction of the beam. Antiprotons for the AD are produced by smashing a beam of protons from the PS onto an iridium target. However, the particles produced by the nuclear interactions are emitted at very wide angles; without a focussing element, all these precious particles would be lost. “A magnetic horn is placed at the exit of the target to focus back a large fraction of the negative particles, including antiprotons, parallel to the beam line and with the right momentum,” explains Marco Calviani, physicist in the EN Department and the expert in charge of the AD targe...

  12. Alteration of the cell adhesion molecule L1 expression in a specific subset of primary afferent neurons contributes to neuropathic pain.

    Science.gov (United States)

    Yamanaka, Hiroki; Obata, Koichi; Kobayashi, Kimiko; Dai, Yi; Fukuoka, Tetsuo; Noguchi, Koichi

    2007-02-01

    The cell adhesion molecule L1 (L1-CAM) plays important functional roles in the developing and adult nervous systems. Here we show that peripheral nerve injury induced dynamic post-transcriptional alteration of L1-CAM in the rat dorsal root ganglia (DRGs) and spinal cord. Sciatic nerve transection (SCNT) changed the expression of L1-CAM protein but not L1-CAM mRNA. In DRGs, SCNT induced accumulation of the L1-CAM into the surface of somata, which resulted in the formation of immunoreactive ring structures in a number of unmyelinated C-fiber neurons. These neurons with L1-CAM-immunoreactive ring structures were heavily colocalized with phosphorylated p38 MAPK. Western blot analysis revealed the increase of full-length L1-CAM and decrease of fragments of L1-CAM after SCNT in DRGs. Following SCNT, L1-CAM-immunoreactive profiles in the dorsal horn showed an increase mainly in pre-synaptic areas of laminae I-II with a delayed onset and colocalized with growth-associated protein 43. In contrast to DRGs, SCNT increased the proteolytic 80-kDa fragment of L1-CAM and decreased full-length L1-CAM in the spinal cord. The intrathecal injection of L1-CAM antibody for the extracellular domain of L1-CAM inhibited activation of p38 MAPK and emergence of ring structures of L1-CAM immunoreactivity in injured DRG neurons. Moreover, inhibition of extracellular L1-CAM binding by intrathecal administration of antibody suppressed the mechanical allodynia and thermal hyperalgesia induced by partial SCNT. Collectively, these data suggest that the modification of L1-CAM in nociceptive pathways might be an important pathomechanism of neuropathic pain.

  13. Activation of ERK signalling by Src family kinases (SFKs) in DRG neurons contributes to hydrogen peroxide (H2O2)-induced thermal hyperalgesia.

    Science.gov (United States)

    Singh, Ajeet Kumar; Vinayak, Manjula

    2017-10-01

    Concomitant generation of reactive oxygen species during tissue inflammation has been recognised as a major factor for the development and the maintenance of hyperalgesia, out of which H 2 O 2 is the major player. However, molecular mechanism of H 2 O 2 induced hyperalgesia is still obscure. The aim of present study is to analyse the mechanism of H 2 O 2 -induced hyperalgesia in rats. Intraplantar injection of H 2 O 2 (5, 10 and 20 µmoles/paw) induced a significant thermal hyperalgesia in the hind paw, confirmed by increased c-Fos activity in dorsal horn of spinal cord. Onset of hyperalgesia was prior to development of oxidative stress and inflammation. Rapid increase in phosphorylation of extracellular signal regulated kinase (ERK) was observed in neurons of dorsal root ganglia after 20 min of H 2 O 2 (10 µmoles/paw) administration, which gradually returned towards normal level within 24 h, following the pattern of thermal hyperalgesia. The expression of TNFR1 followed the same pattern and colocalised with pERK. ERK phosphorylation was observed in NF-200-positive and -negative neurons, indicating the involvement of ERK in C-fibres as well as in A-fibres. Intrathecal preadministration of Src family kinases (SFKs) inhibitor (PP1) and MEK inhibitor (PD98059) prevented H 2 O 2 induced augmentation of ERK phosphorylation and thermal hyperalgesia. Pretreatment of protein tyrosine phosphatases (PTPs) inhibitor (sodium orthovanadate) also diminished hyperalgesia, although it further increased ERK phosphorylation. Combination of orthovanadate with PP1 or PD98059 did not exhibit synergistic antihyperalgesic effect. The results demonstrate SFKs-mediated ERK activation and increased TNFR1 expression in nociceptive neurons during H 2 O 2 induced hyperalgesia. However, the role of PTPs in hyperalgesic behaviour needs further molecular analysis.

  14. Contribution of the dorsal noradrenergic bundle to the effect of amphetamine on acetylcholine turnover

    International Nuclear Information System (INIS)

    Robinson, S.E.

    1986-01-01

    In order to determine the contribution of the noradrenergic projections of the locus coeruleus to the action of amphetamine on cholinergic neurons in several areas of the brain, the dorsal noradrenergic bundle was selectively lesioned by injection of the neurotoxin 6-hydroxydopamine. The bundles of Equithesin-anesthetized male rats were lesioned bilaterally by stereotaxically-placed injections of 6-OHDA. The animals were killed in the microwave and constant rate infusion with phosphoryl ( 2 H 9 )-choline was begun. Levels of ACh and choline and TR /SUB ACh/ were determined by a mass fragmentographic technique. Rats not exhibiting the proper decrease in NE were excluded from all data calculations. It is shown that noradrenergic neurons travelling in the dorsal noradrenergic bundle do not exert a tonic action on cholinergic neurons in the cortex, hippocampus or hypothalamus

  15. Single-prolonged stress induces apoptosis in dorsal raphe nucleus in the rat model of posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Liu Dongjuan

    2012-11-01

    Full Text Available Abstract Introduction Post-traumatic stress disorder (PTSD is an anxiety disorder that develops after exposure to a life-threatening traumatic experience. Meta-analyses of the brainstem showed that midsagittal area of the pons was significantly reduced in patients with PTSD, suggesting a potential apoptosis in dorsal raphe nucleus after single-prolonged stress (SPS. The aim of this study is to investigate whether SPS induces apoptosis in dorsal raphe nucleus in PTSD rats, which may be a possible mechanism of reduced volume of pons and density of gray matter. Methods In this study, rats were randomly divided into 1d, 7d and 14d groups after SPS along with the control group. The apoptosis rate was determined using annexin V-FITC/PI double-labeled flow cytometry (FCM. Levels of Cytochrome c (Cyt-C was examined by Western blotting. Expression of Cyt-C on mitochondria in the dorsal raphe nucleus neuron was determined by enzymohistochemistry under transmission electron microscopy (TEM. The change of thiamine monophosphatase (TMP levels was assessed by enzymohistochemistry under light microscope and TEM. Morphological changes of the ultrastructure of the dorsal raphe nucleus neuron were determined by TEM. Results Apoptotic morphological alterations were observed in dorsal raphe nucleus neuron for all SPS-stimulate groups of rats. The apoptosis rates were significantly increased in dorsal raphe nucleus neuron of SPS rats, along with increased release of cytochrome c from the mitochondria into the cytoplasm, increased expression of Cyt-C and TMP levels in the cytoplasm, which reached to the peak of increase 7 days of SPS. Conclusions The results indicate that SPS induced Cyt-C released from mitochondria into cytosol and apoptosis in dorsal raphe nucleus neuron of rats. Increased TMP in cytoplasm facilitated the clearance of apoptotic cells. We propose that this presents one of the mechanisms that lead to reduced volume of pons and gray matter associated

  16. Effect of biotin supplementation on claw horn growth in young, clinically healthy cattle.

    Science.gov (United States)

    da Silva, Luiz Antônio Franco; Franco, Leandro Guimarães; Atayde, Ingrid Bueno; da Cunha, Paulo Henrique Jorge; de Moura, Maria Ivete; Goulart, Daniel Silva

    2010-06-01

    The effects of orally administered biotin supplementation on the growth of claw horn in young, clinically healthy cattle were analyzed. Twelve, 1-year-old Girolando cattle were randomly assigned to receive either 12.5 mg of diluted powdered biotin (GI) or a control treatment (GII) for 40 consecutive days. Cattle in the GI group showed an average hoof growth of 11.3 +/- 0.72 mm, while those in GII had an average hoof growth of 7.2 +/- 0.78 mm. The results confirmed the positive effect of biotin supplementation on the growth of angle and length of the dorsal hoof wall, hoof sole length, and on resistance to wearing, in young cattle extensively managed.

  17. Application and Research of Ultrasonic Horn in Ultrasonic Ranging System

    Directory of Open Access Journals (Sweden)

    Ju Xiaotao

    2014-05-01

    Full Text Available Aiming at the problem that echo signal is hard to recognize caused by ultrasonic energy’s overquick dispersion and attenuation, a kind of ultrasonic horn is designed. According to the acoustic theory analysis, the ultrasonic horn can increase its radiation energy by improving impedance matching. The ultrasonic horn can make the directivity of sound source sharper and energy more centralized because of the large outlet. The simulation calculation and experiment results prove the effectiveness of ultrasonic horn to improve the scope of ultrasonic ranging.

  18. More on Descriptive Complexity of Second-Order HORN Logics

    OpenAIRE

    Feng, Shiguang; Zhao, Xishun

    2014-01-01

    This paper concerns Gradel's question asked in 1992: whether all problems which are in PTIME and closed under substructures are definable in second-order HORN logic SO-HORN. We introduce revisions of SO-HORN and DATALOG by adding first-order universal quantifiers over the second-order atoms in the bodies of HORN clauses and DATALOG rules. We show that both logics are as expressive as FO(LFP), the least fixed point logic. We also prove that FO(LFP) can not define all of the problems that are i...

  19. Efficiency of partial treatment of cattle infested with horn fly using 40% diazinon

    Directory of Open Access Journals (Sweden)

    Fabiana Alves de Almeida

    Full Text Available The aim of this investigation was to evaluate the efficiency of partial treatment of animals infested with horn flies. Forty-five Guzerat cows between 4 and 7 years of age were divided into three groups (15 cows per group. The treatments were as follows: in groups G33 and G100, 33.3 and 100% of the cows were treated with one insecticide-impregnated ear tag/animal (40% diazinon, respectively, while in the group GC, the cows were not treated (control. The flies on the cervico-dorsal-lumbar region of the cows, in all three groups, were counted every 14 days. The experiment lasted from September 2006 to September 2009. Over this period, six four-month ear tag treatments, with intervals of one to two months, were conducted on both treated groups. The animals of group G33 had a higher infection than those of group G100, and the number of flies ranged from 12 to 27 (group G33 and from 3 to 11 (group G100. However, groups G33 and G100 had lower infection levels than group GC, which presented from 45 to 87 flies. Partial treatment of cattle infested with horn flies using 40% diazinon insecticide is an efficient alternative for controlling this ectoparasite.

  20. Efficiency of partial treatment of cattle infested with horn fly using 40% diazinon.

    Science.gov (United States)

    de Almeida, Fabiana Alves; Alari, Fernando de Oliveira; Seno, Maria Conceição Zocoller; de Lima, Marco Monteiro; Nascimento, Sheila Tavares; Chiquitelli Neto, Marcos

    2013-01-01

    The aim of this investigation was to evaluate the efficiency of partial treatment of animals infested with horn flies. Forty-five Guzerat cows between 4 and 7 years of age were divided into three groups (15 cows per group). The treatments were as follows: in groups G33 and G100, 33.3 and 100% of the cows were treated with one insecticide-impregnated ear tag/animal (40% diazinon), respectively, while in the group GC, the cows were not treated (control). The flies on the cervico-dorsal-lumbar region of the cows, in all three groups, were counted every 14 days. The experiment lasted from September 2006 to September 2009. Over this period, six four-month ear tag treatments, with intervals of one to two months, were conducted on both treated groups. The animals of group G33 had a higher infection than those of group G100, and the number of flies ranged from 12 to 27 (group G33) and from 3 to 11 (group G100). However, groups G33 and G100 had lower infection levels than group GC, which presented from 45 to 87 flies. Partial treatment of cattle infested with horn flies using 40% diazinon insecticide is an efficient alternative for controlling this ectoparasite.

  1. 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.

  2. 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.

  3. Participation of neuronal nitric oxide synthase in experimental neuropathic pain induced by sciatic nerve transection

    Directory of Open Access Journals (Sweden)

    M. Chacur

    2010-04-01

    Full Text Available Nerve injury leads to a neuropathic pain state that results from central sensitization. This phenomenom is mediated by NMDA receptors and may involve the production of nitric oxide (NO. In this study, we investigated the expression of the neuronal isoform of NO synthase (nNOS in the spinal cord of 3-month-old male, Wistar rats after sciatic nerve transection (SNT. Our attention was focused on the dorsal part of L3-L5 segments receiving sensory inputs from the sciatic nerve. SNT resulted in the development of neuropathic pain symptoms confirmed by evaluating mechanical hyperalgesia (Randall and Selitto test and allodynia (von Frey hair test. Control animals did not present any alteration (sham-animals. The selective inhibitor of nNOS, 7-nitroindazole (0.2 and 2 µg in 50 µL, blocked hyperalgesia and allodynia induced by SNT. Immunohistochemical analysis showed that nNOS was increased (48% by day 30 in the lumbar spinal cord after SNT. This increase was observed near the central canal (Rexed’s lamina X and also in lamina I-IV of the dorsal horn. Real-time PCR results indicated an increase of nNOS mRNA detected from 1 to 30 days after SNT, with the highest increase observed 1 day after injury (1469%. Immunoblotting confirmed the increase of nNOS in the spinal cord between 1 and 15 days post-lesion (20%, reaching the greatest increase (60% 30 days after surgery. The present findings demonstrate an increase of nNOS after peripheral nerve injury that may contribute to the increase of NO production observed after peripheral neuropathy.

  4. Zooming Out of Single Neurons Reveals Structure in Mnemonic Representations.

    Science.gov (United States)

    Jazayeri, Mehrdad

    2017-12-20

    In this issue of Neuron, Rossi-Pool et al. (2017) show that the complex and heterogeneous response profiles of individual neurons in the dorsal premotor cortex during comparison of tactile temporal patterns can be understood in terms of two robust activity patterns that emerge across the population. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Wave propagation inside the Agbo horn | Nwachukwu | Nigerian ...

    African Journals Online (AJOL)

    ... comparable to that of modern horns and other musical instruments in emitting harmonious vibrations of even and odd harmonics when excited. This investigation has further shown that the “agbo” horns can be used for fourier analysis and amplitude modulation. They also have characteristics similar to violin, piano, oboe, ...

  6. AFP Algorithm and a Canonical Normal Form for Horn Formulas

    OpenAIRE

    Majdoddin, Ruhollah

    2014-01-01

    AFP Algorithm is a learning algorithm for Horn formulas. We show that it does not improve the complexity of AFP Algorithm, if after each negative counterexample more that just one refinements are performed. Moreover, a canonical normal form for Horn formulas is presented, and it is proved that the output formula of AFP Algorithm is in this normal form.

  7. Contraction core for horn belief change: preliminary report

    CSIR Research Space (South Africa)

    Booth, R

    2010-05-01

    Full Text Available In this paper the authors continue recent investigations into belief change for Horn logic. The main contribution is a result which shows that the construction method for Horn contraction for belief sets based on infraremainder sets, as recently...

  8. Toward a Regional Security Architecture for the Horn of Africa ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Toward a Regional Security Architecture for the Horn of Africa - Phase II. The Horn of Africa region has endured decades of destruction and human suffering due to long and interrelated wars. Moreover, conflict in one country tends to affect its neighbours, mainly through the flow of refugees and weapons. Building on work ...

  9. The natural horn as an efficient sound radiating system ...

    African Journals Online (AJOL)

    Results obtained showed that the locally made horn are efficient sound radiating systems and are therefore excellent for sound production in local musical renditions. These findings, in addition to the portability and low cost of the horns qualify them to be highly recommended for use in music making and for other purposes ...

  10. Occupational cow horn eye injuries in Ibadan, Nigeria | Ibrahim ...

    African Journals Online (AJOL)

    This case series aims to describe the clinical features, management, and outcome of occupational eye injuries caused by cow horns and to recommend possible preventive measures. A review of patients with cow horn inflicted eye injuries seen at the University College Hospital, Ibadan between January 2006, and ...

  11. Insecticide resistance in the horn fly: alternative control strategies.

    Science.gov (United States)

    Oyarzún, M P; Quiroz, A; Birkett, M A

    2008-09-01

    The horn fly, Haematobia irritans (Linnaeus 1758) (Diptera: Muscidae) is one of the most widespread and economically important pests of cattle. Although insecticides have been used for fly control, success has been limited because of the development of insecticide resistance in all countries where the horn fly is found. This problem, along with public pressure for insecticide-free food and the prohibitive cost of developing new classes of compounds, has driven the investigation of alternative control methods that minimize or avoid the use of insecticides. This review provides details of the economic impact of horn flies, existing insecticides used for horn fly control and resistance mechanisms. Current research on new methods of horn fly control based on resistant cattle selection, semiochemicals, biological control and vaccines is also discussed.

  12. Giant cutaneous horn in an African woman: a case report

    Directory of Open Access Journals (Sweden)

    Nthumba Peter M

    2007-12-01

    Full Text Available Abstract Introduction A cutaneous horn is a conical projection of hyperkeratotic epidermis. Though grossly resembling an animal horn, it lacks a bony core. These lesions have been well described in Caucasian patients, as well as in a number of Arabic and Asian patients. Case presentation A young female presented with a large 'horn' of five-year duration, arising from a burn scar. Excision and scalp reconstruction were performed. Histology was reported as verrucoid epidermal hyperplasia with cutaneous horn. Conclusion This may be the first documentation of this lesion in a black African. Although likely rare, it should be considered in the differential diagnosis of dermatologic lesions. Up to 40% of cutaneous horns occur as part of a premalignant or malignant lesion, and surgical extirpation with histological examination is thus more important than the curiosity surrounding these lesions.

  13. A novel perspective on neuron study: damaging and promoting effects in different neurons induced by mechanical stress.

    Science.gov (United States)

    Wang, Yazhou; Wang, Wei; Li, Zong; Hao, Shilei; Wang, Bochu

    2016-10-01

    A growing volume of experimental evidence demonstrates that mechanical stress plays a significant role in growth, proliferation, apoptosis, gene expression, electrophysiological properties and many other aspects of neurons. In this review, first, the mechanical microenvironment and properties of neurons under in vivo conditions are introduced and analyzed. Second, research works in recent decades on the effects of different mechanical forces, especially compression and tension, on various neurons, including dorsal root ganglion neurons, retinal ganglion cells, cerebral cortex neurons, hippocampus neurons, neural stem cells, and other neurons, are summarized. Previous research results demonstrate that mechanical stress can not only injure neurons by damaging their morphology, impacting their electrophysiological characteristics and gene expression, but also promote neuron self-repair. Finally, some future perspectives in neuron research are discussed.

  14. Functional genomics of the horn fly, Haematobia irritans (Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Quiroz-Romero Héctor

    2011-02-01

    Full Text Available Abstract Background The horn fly, Haematobia irritans (Linnaeus, 1758 (Diptera: Muscidae is one of the most important ectoparasites of pastured cattle. Horn flies infestations reduce cattle weight gain and milk production. Additionally, horn flies are mechanical vectors of different pathogens that cause disease in cattle. The aim of this study was to conduct a functional genomics study in female horn flies using Expressed Sequence Tags (EST analysis and RNA interference (RNAi. Results A cDNA library was made from whole abdominal tissues collected from partially fed adult female horn flies. High quality horn fly ESTs (2,160 were sequenced and assembled into 992 unigenes (178 contigs and 814 singlets representing molecular functions such as serine proteases, cell metabolism, mitochondrial function, transcription and translation, transport, chromatin structure, vitellogenesis, cytoskeleton, DNA replication, cell response to stress and infection, cell proliferation and cell-cell interactions, intracellular trafficking and secretion, and development. Functional analyses were conducted using RNAi for the first time in horn flies. Gene knockdown by RNAi resulted in higher horn fly mortality (protease inhibitor functional group, reduced oviposition (vitellogenin, ferritin and vATPase groups or both (immune response and 5'-NUC groups when compared to controls. Silencing of ubiquitination ESTs did not affect horn fly mortality and ovisposition while gene knockdown in the ferritin and vATPse functional groups reduced mortality when compared to controls. Conclusions These results advanced the molecular characterization of this important ectoparasite and suggested candidate protective antigens for the development of vaccines for the control of horn fly infestations.

  15. Distribution of horn flies on individual cows as a percentage of the total horn fly population.

    Science.gov (United States)

    Pruett, J H; Steelman, C D; Miller, J A; Pound, J M; George, J E

    2003-10-20

    Twenty-three mixed-breed herd cows were phenotyped for their ability to serve as a suitable host for Haematobia irritans, the horn fly. Based upon consistent observations within the lower quartile or upper quartile of individual fly counts, four cows were phenotyped as low carriers and five cows were phenotyped as high carriers of horn flies. The cows designated as low carriers consistently carried levels of flies below the economic threshold. However, during a period of fly population explosion, low carriers harbored flies well above the economic threshold. Although the number of flies counted on these low carrying cattle increased as the population increased, the relative percentage of the population that they carried changed very little. A hypothesis is proposed to explain this observation, and future studies are suggested.

  16. Horn belief change: A contraction core

    CSIR Research Space (South Africa)

    Booth, R

    2010-08-01

    Full Text Available e-contractions. The argument is based on the observation that the convexity result for full propositional logic [2, Proposition 2.1] does not hold for Horn logic. Example 1 Let H = CnHL(fp! q; q ! rg). Then, for the e- contraction of H with p ! r..., and the Failure postulate. (H e 6) If 2 H n (H ’), then there exists an X s.t.T (H?e’) X H and X 6j= ’, but X [ f g j= ’ (H e 7) If j= ’, then H e ’ = H (Failure) (H e 6) resembles the Relevance postulate for base contraction. Also, it is an unusual...

  17. On the origin of Ammon's horn.

    Science.gov (United States)

    Iniesta, I

    2014-10-01

    Greek and Roman worship of their gods and myths go back to Ancient Egyptian times. Images engraved in Greco-Roman coinage range from references to the assassination of Caesar and legendary stories like the arrival of a snake shaped demi-god Aesculapius to save the Romans from the plague, to invocations of major deities including Apollo the physician or Ammon the protector. Depicted with the horns of a ram, Ammon was adopted by the Greeks as an epithet of Zeus and later incorporated by the Romans as Jupiter. References to the cult of Ammon appear on tetradrachms minted for Alexander The Great and on provincial Roman coins struck under Claudius. It is thrilling to hold a coin depicting Marcus Aurelius with Salus on the reverse and think that it could have been handed to Galen in payment for his services. However, it is rare to find figures other than rulers on coins and the physician of Pergamum is no exception. Inspired by the Renaissance school of Padua, French anatomists in the Enlightenment (Garengeot in 1742 and Flurant in 1752) continued reviving ancient myths and named the curve-shaped-inner portion of the temporal lobe Ammon's horn. Outstanding scholars who studied this primitive structure of the brain included Lorente de Nó and his mentor Cajal, whose portrait appeared on fifty-pesetas notes issued in 1935. As primary sources of great archaeological and artistic value, Greco-Roman coins provide information about the origins of the myths and gods of classical antiquity and continue to inspire the arts and sciences to this day. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  18. TLR4 receptor expression and function in F11 dorsal root ganglion × neuroblastoma hybrid cells.

    Science.gov (United States)

    Hashemian, Sanaz; Alhouayek, Mireille; Fowler, Christopher J

    2017-11-01

    TLR4 respond to bacterial LPS to produce inflammatory cytokines. TLR4 are expressed in dorsal root ganglia and play a role in pain. F11 dorsal root ganglia × mouse neuroblastoma cells possess many of the properties seen in nociceptive dorsal root ganglia neuronal cells. Here, we investigated the effect of 2 h and 6 h treatment with LPS upon the expression of inflammatory proteins in undifferentiated and differentiated F11 cells. The cells expressed mRNA for TRL4 (mouse, not rat) and proteins involved in TLR4 signaling. TLR4 expression was confirmed using immunohistochemistry. LPS produced modest increases in mouse and rat IL-6 and in mouse cyclooxygenase-2 levels in undifferentiated cells, but did not significantly affect mouse TNF-α expression. This contrasts with the robust effects of LPS upon cyclooxygenase-2 expression in cultured dorsal root ganglia neurons. F11 cells expressed the endocannabinoid metabolizing enzymes fatty acid amide hydrolase and N-acylethanolamine acid amidase (both murine), which were functionally active. These data suggest that F11 cells are not a useful model for the study of LPS-mediated effects but may be useful for the study of endocannabinoid catabolism.

  19. EST and microarray analysis of horn development in Onthophagus beetles

    Directory of Open Access Journals (Sweden)

    Tang Zuojian

    2009-10-01

    Full Text Available Abstract Background The origin of novel traits and their subsequent diversification represent central themes in evo-devo and evolutionary ecology. Here we explore the genetic and genomic basis of a class of traits that is both novel and highly diverse, in a group of organisms that is ecologically complex and experimentally tractable: horned beetles. Results We developed two high quality, normalized cDNA libraries for larval and pupal Onthophagus taurus and sequenced 3,488 ESTs that assembled into 451 contigs and 2,330 singletons. We present the annotation and a comparative analysis of the conservation of the sequences. Microarrays developed from the combined libraries were then used to contrast the transcriptome of developing primordia of head horns, prothoracic horns, and legs. Our experiments identify a first comprehensive list of candidate genes for the evolution and diversification of beetle horns. We find that developing horns and legs show many similarities as well as important differences in their transcription profiles, suggesting that the origin of horns was mediated partly, but not entirely, by the recruitment of genes involved in the formation of more traditional appendages such as legs. Furthermore, we find that horns developing from the head and prothorax differ in their transcription profiles to a degree that suggests that head and prothoracic horns are not serial homologs, but instead may have evolved independently from each other. Conclusion We have laid the foundation for a systematic analysis of the genetic basis of horned beetle development and diversification with the potential to contribute significantly to several major frontiers in evolutionary developmental biology.

  20. Formal verification of communication protocols using quantized Horn clauses

    Science.gov (United States)

    Balu, Radhakrishnan

    2016-05-01

    The stochastic nature of quantum communication protocols naturally lends itself for expression via probabilistic logic languages. In this work we describe quantized computation using Horn clauses and base the semantics on quantum probability. Turing computable Horn clauses are very convenient to work with and the formalism can be extended to general form of first order languages. Towards this end we build a Hilbert space of H-interpretations and a corresponding non commutative von Neumann algebra of bounded linear operators. We demonstrate the expressive power of the language by casting quantum communication protocols as Horn clauses.

  1. Everard Home, John Hunter, and cutaneous horns: a historical review.

    Science.gov (United States)

    Bondeson, J

    2001-08-01

    A cutaneous horn is a protrusion from the skin made up of cornified material. These horns can be derived from a variety of epidermal lesions, both benign and malignant. This historical article reviews a number of early instances of cutaneous horns, some reported in the 16th and 17th centuries. The Danish anatomist Thomas Bartholin was the first to have a correct theory of the ethiology of these horny growths, and the English surgeons John Hunter and Everard Home confirmed his findings in the late 18th century.

  2. Neural correlates of auditory recognition memory in the primate dorsal temporal pole

    OpenAIRE

    Ng, Chi-Wing; Plakke, Bethany; Poremba, Amy

    2013-01-01

    Temporal pole (TP) cortex is associated with higher-order sensory perception and/or recognition memory, as human patients with damage in this region show impaired performance during some tasks requiring recognition memory (Olson et al. 2007). The underlying mechanisms of TP processing are largely based on examination of the visual nervous system in humans and monkeys, while little is known about neuronal activity patterns in the auditory portion of this region, dorsal TP (dTP; Poremba et al. ...

  3. Superficial Dorsal Vein Injury/Thrombosis Presenting as False Penile Fracture Requiring Dorsal Venous Ligation

    Directory of Open Access Journals (Sweden)

    Arash Rafiei, MD

    2014-12-01

    Conclusion: Early exploration of patients with suspected penile fracture provides excellent results with maintenance of erectile function. Also, in the setting of dorsal vein thrombosis, ligation preserves the integrity of the penile tissues and avoids unnecessary complications from conservative management. Rafiei A, Hakky TS, Martinez D, Parker J, and Carrion R. Superficial dorsal vein injury/thrombosis presenting as false penile fracture requiring dorsal venous ligation. Sex Med 2014;2:182–185.

  4. Development and degeneration of dorsal root ganglia in the absence of the HMG-domain transcription factor Sox10

    DEFF Research Database (Denmark)

    Sonnenberg-Riethmacher, Eva; Miehe, Michaela; Stolt, Claus C.

    2001-01-01

    neurogenesis seemed initially normal. A degeneration of motoneurons and sensory neurons occurred later in development. The mechanism that leads to the dramatic effects on the neural crest derived cell lineages in the dorsal root ganglia (DRG), however, has not been examined up to now. Here, we provide...

  5. Mirror System Activity for Action and Language Is Embedded in the Integration of Dorsal and Ventral Pathways

    Science.gov (United States)

    Arbib, Michael A.

    2010-01-01

    We develop the view that the involvement of mirror neurons in embodied experience grounds brain structures that underlie language, but that many other brain regions are involved. We stress the cooperation between the dorsal and ventral streams in praxis and language. Both have perceptual and motor schemas but the perceptual schemas in the dorsal…

  6. [Vimentin and S100 protein in the developing rat dorsal root ganglion cells].

    Science.gov (United States)

    Kolos, Ye A; Korzhevskiy, D E

    2013-01-01

    The aim of this research was to study the expression of vimentin, one of the intermediate filament proteins, and S100 protein in the cells of developing dorsal root ganglion in prenatal ontogenesis in Wistar rat embryos (n=22) on 12-19 days of development and in newborn rats (n=6). Immunohistochemical staining methods were used to study the formation of rat dorsal root ganglion glial cells. Vimentin-immunopositive neural and glial progenitor cells were present in dorsal root ganglion primordia in rat embryos at 12-17 prenatal days. At the later stages (day 19 of prenatal life and day 1 of postnatal life) vimentin was found to be synthesized only by the differentiating glial cells. It was shown that at the same time, S100 protein was first detected in the glial cells of rat dorsal root ganglion. On postnatal day 1, the tendency was noted for the accumulation of S100 protein in the larger neurons, that was characteristic to mature dorsal root ganglia.

  7. Differential modulation of visual object processing in dorsal and ventral stream by stimulus visibility.

    Science.gov (United States)

    Ludwig, Karin; Sterzer, Philipp; Kathmann, Norbert; Hesselmann, Guido

    2016-10-01

    As a functional organization principle in cortical visual information processing, the influential 'two visual systems' hypothesis proposes a division of labor between a dorsal "vision-for-action" and a ventral "vision-for-perception" stream. A core assumption of this model is that the two visual streams are differentially involved in visual awareness: ventral stream processing is closely linked to awareness while dorsal stream processing is not. In this functional magnetic resonance imaging (fMRI) study with human observers, we directly probed the stimulus-related information encoded in fMRI response patterns in both visual streams as a function of stimulus visibility. We parametrically modulated the visibility of face and tool stimuli by varying the contrasts of the masks in a continuous flash suppression (CFS) paradigm. We found that visibility - operationalized by objective and subjective measures - decreased proportionally with increasing log CFS mask contrast. Neuronally, this relationship was closely matched by ventral visual areas, showing a linear decrease of stimulus-related information with increasing mask contrast. Stimulus-related information in dorsal areas also showed a dependency on mask contrast, but the decrease rather followed a step function instead of a linear function. Together, our results suggest that both the ventral and the dorsal visual stream are linked to visual awareness, but neural activity in ventral areas more closely reflects graded differences in awareness compared to dorsal areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Development of mouse dorsal root ganglia: an autoradiographic and quantitative study

    International Nuclear Information System (INIS)

    Lawson, S.N.; Biscoe, T.J.

    1979-01-01

    Pulse labelling with tritiated thymidine was used to determine the cell birthdays of dorsal root ganglion (DRG) neurons in foetal mice. The peak number of cell birthdays occurred at 11.5 days foetal age in cervical DRGs, and at 12.5 days in lumbar DRGs. The satellite cells were becoming heavily labelled by day 13.5 in lumbar and some hours earlier in cervical regions. A very sharp peak of satellite cell labelling was seen at 13 days in the lumbar region. Evidence for the existence of more than one neuronal cell type is presented. The earliest cells to stop dividing were part of a widely spread distribution which included all the large neurons. The birthdays of the population of small neurons began later and continued for at least 48 h after division of the large cells had ceased. (author)

  9. Failure of action potential propagation in sensory neurons: mechanisms and loss of afferent filtering in C-type units after painful nerve injury

    NARCIS (Netherlands)

    Gemes, Geza; Koopmeiners, Andrew; Rigaud, Marcel; Lirk, Philipp; Sapunar, Damir; Bangaru, Madhavi Latha; Vilceanu, Daniel; Garrison, Sheldon R.; Ljubkovic, Marko; Mueller, Samantha J.; Stucky, Cheryl L.; Hogan, Quinn H.

    2013-01-01

    The T-junction of sensory neurons in the dorsal root ganglion (DRG) is a potential impediment to action potential (AP) propagation towards the CNS. Using intracellular recordings from rat DRG neuronal somata during stimulation of the dorsal root, we determined that the maximal rate at which all of

  10. High doses of salicylate reduces glycinergic inhibition in the dorsal cochlear nucleus of the rat.

    Science.gov (United States)

    Zugaib, João; Ceballos, Cesar C; Leão, Ricardo M

    2016-02-01

    High doses of salicylate induce reversible tinnitus in experimental animals and humans, and is a common tinnitus model. Salicylate probably acts centrally and induces hyperactivity in specific auditory brainstem areas like the dorsal cochlear nucleus (DCN). However, little is known about the effect of high doses of salicylate in synapses and neurons of the DCN. Here we investigated the effects of salicylate on the excitability and evoked and spontaneous neurotransmission in the main neurons (fusiform, cartwheel and tuberculoventral) and synapses of the DCN using whole cell recordings in slices containing the DCN. For this, we incubate the slices for at least 1 h in solution with 1.4 mM salicylate, and recorded action potentials and evoked and spontaneous synaptic currents in fusiform, cartwheel (CW) and putative tuberculoventral (TBV) neurons. We found that incubation with salicylate did not affect the firing of fusiform and TBV neurons, but decreased the spontaneous firing of cartwheel neurons, without affecting AP threshold or complex spikes. Evoked and spontaneous glutamatergic neurotransmission on the fusiform and CW neurons cells was unaffected by salicylate and evoked glycinergic neurotransmission on fusiform neurons was also unchanged by salicylate. On the other hand spontaneous glycinergic transmission on fusiform neurons was reduced in the presence of salicylate. We conclude that high doses of salicylate produces a decreased inhibitor drive on DCN fusiform neurons by reducing the spontaneous firing of cartwheel neurons, but this effect is not able to increase the excitability of fusiform neurons. So, the mechanisms of salicylate-induced tinnitus are probably more complex than simple changes in the neuronal firing and basal synaptic transmission in the DCN. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Beta-band intermuscular coherence: a novel biomarker of upper motor neuron dysfunction in motor neuron disease.

    Science.gov (United States)

    Fisher, Karen M; Zaaimi, Boubker; Williams, Timothy L; Baker, Stuart N; Baker, Mark R

    2012-09-01

    In motor neuron disease, the focus of therapy is to prevent or slow neuronal degeneration with neuroprotective pharmacological agents; early diagnosis and treatment are thus essential. Incorporation of needle electromyographic evidence of lower motor neuron degeneration into diagnostic criteria has undoubtedly advanced diagnosis, but even earlier diagnosis might be possible by including tests of subclinical upper motor neuron disease. We hypothesized that beta-band (15-30 Hz) intermuscular coherence could be used as an electrophysiological marker of upper motor neuron integrity in such patients. We measured intermuscular coherence in eight patients who conformed to established diagnostic criteria for primary lateral sclerosis and six patients with progressive muscular atrophy, together with 16 age-matched controls. In the primary lateral sclerosis variant of motor neuron disease, there is selective destruction of motor cortical layer V pyramidal neurons and degeneration of the corticospinal tract, without involvement of anterior horn cells. In progressive muscular atrophy, there is selective degeneration of anterior horn cells but a normal corticospinal tract. All patients with primary lateral sclerosis had abnormal motor-evoked potentials as assessed using transcranial magnetic stimulation, whereas these were similar to controls in progressive muscular atrophy. Upper and lower limb intermuscular coherence was measured during a precision grip and an ankle dorsiflexion task, respectively. Significant beta-band coherence was observed in all control subjects and all patients with progressive muscular atrophy tested, but not in the patients with primary lateral sclerosis. We conclude that intermuscular coherence in the 15-30 Hz range is dependent on an intact corticospinal tract but persists in the face of selective anterior horn cell destruction. Based on the distributions of coherence values measured from patients with primary lateral sclerosis and control

  12. Cutaneous horn and thermal keratosis in erythema AB igne

    Directory of Open Access Journals (Sweden)

    Sood Apra

    2002-01-01

    Full Text Available A 46 - year - old Kashmiri lady developed erythema ab igne on both legs. She subsequently developed multiple keratoses and a cutaneous horn in the involved skin. An uncommon association of these three clinical conditions is being presented.

  13. Application of TEM horn antenna in radiating NEMP simulator

    International Nuclear Information System (INIS)

    Wang, Yun; Chen, Yongguang; Wang, Qingguo

    2013-01-01

    In order to design a small radiating nuclear electromagnetic pulse simulator with fast rise time, we have investigated the application of TEM horn antenna in this kind of simulator. The TEM horn antenna is excitated by the integral double exponential pulse. Farfield response in time domain is analyzed based on the step response formula which is derived from the equivalent transmission line model of TEM horn antenna. Principle of antenna parameters selection is determined. The results of numerical calculation give a show of the radiation waveform and some problems. Then experiments are implemented and results are compared with the radiation waveforms generated by double exponential pulse excitation. It suggests that the TEM horn antenna can be used as radiating antenna in the NEMP simulator, which can radiate double-exponent-like pulse with the integral double exponential pulse as excitation. Meanwhile, impedance loading can improve farfield waveforms and enhance the low-frequency radiating ability of antenna.

  14. The issue of ventral versus dorsal approach in bulbar urethral ...

    African Journals Online (AJOL)

    E. Palminteri

    increased over time the use of Ventral Graft and decreased the use of dorsal graft [7]. From surgical point of view, the Barbagli Dorsal Grafting by Dor- sal approach ... seems reduce the risk of fistula; in reality there is a similar rate of fistula with both ventral and dorsal grafting. The disadvantage of the dorsal approach is that it ...

  15. Attempts to conduct fatigue analysis of horn structures

    Science.gov (United States)

    Kozien, Marek S.; Nieslony, Adam

    2018-01-01

    In the article, the problem of estimating the lifespan of the magnetic lens' (horns) structure, is discussed. Due to pulse-type excitation by current flow, the relatively broad frequency band of stress component function is obtained. Moreover, due to repetition, the problem of pulse resonance can be obtained. The fatigue life prediction is done on the spectral attempt. The analysis was performed for two types of horn structures: the CERN NuFACT one and the EUROnu designed one.

  16. Fabrication and Testing of Pyramidal X- Band Standard Horn Antenna

    OpenAIRE

    Hasan F. Khazaal; Haider Th. Salim Alrikabi; Anwar N. Mohammed Ali; Kadhim A. Neamah; Ali S. Shanan

    2017-01-01

    Standard horn antennas are an important device to evaluate many types of antennas, since they are used as a reference to any type of antennas within the microwave frequency bands. In this project the fabrication process and tests of standard horn antenna operating at X-band frequencies have been proposed. The fabricated antenna passed through multi stages of processing of its parts until assembling the final product. These stages are (milling, bending, fitting and welding). The assembled ante...

  17. Combating Rhino Horn Trafficking: The Need to Disrupt Criminal Networks.

    Directory of Open Access Journals (Sweden)

    Timothy C Haas

    Full Text Available The onslaught on the World's wildlife continues despite numerous initiatives aimed at curbing it. We build a model that integrates rhino horn trade with rhino population dynamics in order to evaluate the impact of various management policies on rhino sustainability. In our model, an agent-based sub-model of horn trade from the poaching event up through a purchase of rhino horn in Asia impacts rhino abundance. A data-validated, individual-based sub-model of the rhino population of South Africa provides these abundance values. We evaluate policies that consist of different combinations of legal trade initiatives, demand reduction marketing campaigns, increased anti-poaching measures within protected areas, and transnational policing initiatives aimed at disrupting those criminal syndicates engaged in horn trafficking. Simulation runs of our model over the next 35 years produces a sustainable rhino population under only one management policy. This policy includes both a transnational policing effort aimed at dismantling those criminal networks engaged in rhino horn trafficking-coupled with increases in legal economic opportunities for people living next to protected areas where rhinos live. This multi-faceted approach should be the focus of the international debate on strategies to combat the current slaughter of rhino rather than the binary debate about whether rhino horn trade should be legalized. This approach to the evaluation of wildlife management policies may be useful to apply to other species threatened by wildlife trafficking.

  18. Combating Rhino Horn Trafficking: The Need to Disrupt Criminal Networks.

    Science.gov (United States)

    Haas, Timothy C; Ferreira, Sam M

    2016-01-01

    The onslaught on the World's wildlife continues despite numerous initiatives aimed at curbing it. We build a model that integrates rhino horn trade with rhino population dynamics in order to evaluate the impact of various management policies on rhino sustainability. In our model, an agent-based sub-model of horn trade from the poaching event up through a purchase of rhino horn in Asia impacts rhino abundance. A data-validated, individual-based sub-model of the rhino population of South Africa provides these abundance values. We evaluate policies that consist of different combinations of legal trade initiatives, demand reduction marketing campaigns, increased anti-poaching measures within protected areas, and transnational policing initiatives aimed at disrupting those criminal syndicates engaged in horn trafficking. Simulation runs of our model over the next 35 years produces a sustainable rhino population under only one management policy. This policy includes both a transnational policing effort aimed at dismantling those criminal networks engaged in rhino horn trafficking-coupled with increases in legal economic opportunities for people living next to protected areas where rhinos live. This multi-faceted approach should be the focus of the international debate on strategies to combat the current slaughter of rhino rather than the binary debate about whether rhino horn trade should be legalized. This approach to the evaluation of wildlife management policies may be useful to apply to other species threatened by wildlife trafficking.

  19. Restoration of the Golden Horn Estuary (Halic).

    Science.gov (United States)

    Coleman, Heather M; Kanat, Gurdal; Aydinol Turkdogan, F Ilter

    2009-12-01

    Restoration of the iconic Golden Horn Estuary in Istanbul, Turkey was a substantial political, logistical, ecological, and social challenge. Forty years of uncontrolled industrial and urban growth resulted in thick layers of anoxic sediment, toxic bacteria, strong hydrogen sulfide odor, and ecologically unlivable conditions. The major components of restoration, spanning two decades, have included (1) demolition and relocation of industries and homes along the shore, (2) creation of wastewater infrastructure, (3) removal of anoxic sludge from the estuary, (4) removal of a floating bridge that impeded circulation, and (5) creation of cultural and social facilities. Although Turkey is not known as an environmental leader in pollution control, the sum of these efforts was largely successful in revitalizing the area through dramatic water quality improvement. Consequently, the estuary is once again inhabitable for aquatic life as well as amenable to local resource users and foreign visitors, and Istanbul has regained a lost sense of cultural identity. This paper focuses on literature review and personal interviews to discuss the causes of degradation, solutions employed to rehabilitate the estuary, and subsequent physicochemical, ecological, and social changes.

  20. Potential for Cell-Transplant Therapy with Human Neuronal Precursors to Treat Neuropathic Pain in Models of PNS and CNS Injury: Comparison of hNT2.17 and hNT2.19 Cell Lines

    Directory of Open Access Journals (Sweden)

    Mary J. Eaton

    2012-01-01

    Full Text Available Effective treatment of sensory neuropathies in peripheral neuropathies and spinal cord injury (SCI is one of the most difficult problems in modern clinical practice. Cell therapy to release antinociceptive agents near the injured spinal cord is a logical next step in the development of treatment modalities. But few clinical trials, especially for chronic pain, have tested the potential of transplant of cells to treat chronic pain. Cell lines derived from the human neuronal NT2 cell line parentage, the hNT2.17 and hNT2.19 lines, which synthesize and release the neurotransmitters gamma-aminobutyric acid (GABA and serotonin (5HT, respectively, have been used to evaluate the potential of cell-based release of antinociceptive agents near the lumbar dorsal (horn spinal sensory cell centers to relieve neuropathic pain after PNS (partial nerve and diabetes-related injury and CNS (spinal cord injury damage in rat models. Both cell lines transplants potently and permanently reverse behavioral hypersensitivity without inducing tumors or other complications after grafting. Functioning as cellular minipumps for antinociception, human neuronal precursors, like these NT2-derived cell lines, would likely provide a useful adjuvant or replacement for current pharmacological treatments for neuropathic pain.

  1. The dorsal visual stream revisited: Stable circuits or dynamic pathways?

    Science.gov (United States)

    Galletti, Claudio; Fattori, Patrizia

    2018-01-01

    In both macaque and human brain, information regarding visual motion flows from the extrastriate area V6 along two different paths: a dorsolateral one towards areas MT/V5, MST, V3A, and a dorsomedial one towards the visuomotor areas of the superior parietal lobule (V6A, MIP, VIP). The dorsolateral visual stream is involved in many aspects of visual motion analysis, including the recognition of object motion and self motion. The dorsomedial stream uses visual motion information to continuously monitor the spatial location of objects while we are looking and/or moving around, to allow skilled reaching for and grasping of the objects in structured, dynamically changing environments. Grasping activity is present in two areas of the dorsal stream, AIP and V6A. Area AIP is more involved than V6A in object recognition, V6A in encoding vision for action. We suggest that V6A is involved in the fast control of prehension and plays a critical role in biomechanically selecting appropriate postures during reach to grasp behaviors. In everyday life, numerous functional networks, often involving the same cortical areas, are continuously in action in the dorsal visual stream, with each network dynamically activated or inhibited according to the context. The dorsolateral and dorsomedial streams represent only two examples of these networks. Many others streams have been described in the literature, but it is worthwhile noting that the same cortical area, and even the same neurons within an area, are not specific for just one functional property, being part of networks that encode multiple functional aspects. Our proposal is to conceive the cortical streams not as fixed series of interconnected cortical areas in which each area belongs univocally to one stream and is strictly involved in only one function, but as interconnected neuronal networks, often involving the same neurons, that are involved in a number of functional processes and whose activation changes dynamically according

  2. The predominantly HEAT-like motif structure of huntingtin and its association and coincident nuclear entry with dorsal, an NF-kB/Rel/dorsal family transcription factor

    Directory of Open Access Journals (Sweden)

    Gusella James F

    2002-10-01

    Full Text Available Abstract Background Huntington's disease (HD pathogenesis is due to an expanded polyglutamine tract in huntingtin, but the specificity of neuronal loss compared with other polyglutamine disorders also implies a role for the protein's unknown inherent function. Huntingtin is moderately conserved, with 10 HEAT repeats reported in its amino-terminal half. HD orthologues are evident in vertebrates and Drosophila, but not in Saccharomyces cerevisiae, Caenorhabditis elegans or Arabidopsis thaliana, a phylogenetic profile similar to the NF-kB/Rel/dorsal family transcription factors, suggesting a potential functional relationship. Results We initially tested the potential for a relationship between huntingtin and dorsal by overexpression experiments in Drosophila S2 cells. Drosophila huntingtin complexes via its carboxyl-terminal region with dorsal, and the two enter the nucleus concomitantly, partly in a lipopolysaccharide (LPS- and Nup88-dependent manner. Similarly, in HeLa cell extracts, human huntingtin co-immunoprecipitates with NF-kB p50 but not with p105. By cross-species comparative analysis, we find that the carboxyl-terminal segment of huntingtin that mediates the association with dorsal possesses numerous HEAT-like sequences related to those in the amino-terminal segment. Thus, Drosophila and vertebrate huntingtins are composed predominantly of 28 to 36 degenerate HEAT-like repeats that span the entire protein. Conclusion Like other HEAT-repeat filled proteins, huntingtin is made up largely of degenerate HEAT-like sequences, suggesting that it may play a scaffolding role in the formation of particular protein-protein complexes. While many proteins have been implicated in complexes with the amino-terminal region of huntingtin, the NF-kB/Rel/dorsal family transcription factors merit further examination as direct or indirect interactors with huntingtin's carboxyl-terminal segment.

  3. Neglected dorsal dislocation of the scaphoid

    Directory of Open Access Journals (Sweden)

    Amaravati Rajkumar

    2009-01-01

    Full Text Available Isolated dislocation of the scaphoid is very rare. A 45-year old male, industrial worker reported two and half months after injury with wrist pain and swelling on the dorsum of left wrist. He was diagnosed as neglected dorsal dislocation of scaphoid. Proximal row carpectomy with capsular interposition was done stabilizing the distal carpus on the radius using Kirschner wires. At-12 months follow-up the patient had good wrist function and was satisfied with the outcome of the treatment. We hereby report this neglected dorsal dislocation of scaphoid in view of rarity and discuss the various options for management.

  4. Wave power plant at Horns Rev. Screening[Denmark]; Boelgekraftanlaeg ved Horns Rev. Screening

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Hans C.; Nielsen, Kim; Steenstrup, P.R.; Friis-Madsen, E.; Wigant, L.

    2005-12-15

    The objective for the analysis has been to establish data for the sea at Horns Rev wind farm in the North Sea in order to assess the opportunity for using the site as test site for demonstration of wave energy devices exemplified by three different devices under development in Denmark. For comparison alternative sites like Hanstholm, Samsoe and Nissum Bredning are also assessed as well as the test centre EMEC at the Orkney Islands and the proposed test site Wave Hub at the north coast of Cornwall. The analysis shows that it is possible without major technical problems to connect 2-4 MW power generated by 3 different wave energy devices (AquaBuOY, Wave Star Energy and Wave Dragon) to the wind farm at Horns Rev (www.hornsrev.dk). The expenses for connection and regulation within the wind farm is about 200,000 DKK (30,00 EURO). On top of this comes the cost for individual sub sea cable connection to the wave devices, pull in of the sub sea cable through the existing J-tube in turbine T04 and the necessary regulation/control system in the individual wave devices to avoid damaging the power system in case of too high production. The analysis of the co-production of wind and wave power is dealt with in a separate report which shows that over a time period of half to one hour the time variation for wind generated electricity is 3 times as large as for wave energy generated power based on the actual measurement at Horns Rev. Further on the analysis shows that the wave generated power is more predictable than wind energy generated power as the power from the waves first is present about 2 hours after the wind is acting and last for 3 to 6 hours after the wind dies out; 6 to 12 hours with wind from west. The time is off course strongly depending of the direction of the wind i.e. the fetch. As this special report has a more general scope than the analysis as such it is reported in English (Annex Report II). The analysis shows that it is up to the individual device developer

  5. Stem cells from wildtype and Friedreich's ataxia mice present similar neuroprotective properties in dorsal root ganglia cells.

    Directory of Open Access Journals (Sweden)

    Jonathan Jones

    Full Text Available Many neurodegenerative disorders share a common susceptibility to oxidative stress, including Alzheimer's, Parkinson Disease, Huntington Disease and Friedreich's ataxia. In a previous work, we proved that stem cell-conditioned medium increased the survival of cells isolated from Friedreich's ataxia patients, when submitted to oxidative stress. The aim of the present work is to confirm this same effect in dorsal root ganglia cells isolated from YG8 mice, a mouse model of Friedreich's ataxia. In this disorder, the neurons of the dorsal root ganglia are the first to degenerate. Also, in this work we cultured mesenchymal stem cells isolated from YG8 mice, in order to compare them with their wildtype counterpart. To this end, dorsal root ganglia primary cultures isolated from YG8 mice were exposed to oxidative stress and cultured with conditioned medium from either wildtype or YG8 stem cells. As a result, the conditioned medium increased the survival of the dorsal root ganglia cells. This coincided with an increase in oxidative stress-related markers and frataxin expression levels. BDNF, NT3 and NT4 trophic factors were detected in the conditioned medium of both wild-type and YG8 stem cells, all which bind to the various neuronal cell types present in the dorsal root ganglia. No differences were observed in the stem cells isolated from wildtype and YG8 mice. The results presented confirm the possibility that autologous stem cell transplantation may be a viable therapeutic approach in protecting dorsal root ganglia neurons of Friedreich's ataxia patients.

  6. Activation of nuclear factor-kappa B via endogenous tumor necrosis factor alpha regulates survival of axotomized adult sensory neurons

    NARCIS (Netherlands)

    Fernyhough, P; Smith, DR; Schapansky, J; Van Der Ploeg, R; Gardiner, NJ; Tweed, CW; Kontos, A; Freeman, L; Purves-Tyson, TD; Glazner, GW

    2005-01-01

    Embryonic dorsal root ganglion (DRG) neurons die after axonal damage in vivo, and cultured embryonic DRG neurons require exogenous neurotrophic factors that activate the neuroprotective transcription factor nuclear factor-kappaB(NF-kappaB) for survival. In contrast, adult DRG neurons survive

  7. The Main Symptoms in Dorsal Sleep Apnea - Hypopnea Syndrome

    Directory of Open Access Journals (Sweden)

    Mihaela Alexandra POP

    2014-09-01

    Full Text Available OSAHS is a chronic, multifactorial disease, accompanied by significant and complex symptoms. The aim of this study was to evaluate the relationship between OSAHS and dorsal AHI in order to improve early diagnosis of dorsal sleep apnea-hypopnea syndrome. There were significant statistical differences between: the dorsal AHI Mean of the group without excessive daytime sleepiness as opposed to the dorsal AHI Mean of the group with excessive daytime sleepiness; the dorsal AHI Mean of the group without snoring as opposed to the dorsal AHI Mean of the group with snoring; the dorsal AHI Mean of the group without restless sleep as opposed to the dorsal AHI Mean of the group with restless sleep; the dorsal AHI Mean of the group without dyspnea as opposed to the dorsal AHI Mean of the group with dyspnea; the dorsal AHI Mean of the group without night sweats as opposed to the dorsal AHI Mean of the group with night sweats; the dorsal AHI Mean of the group without irritability as opposed to the dorsal AHI Mean of the group with irritability and the dorsal AHI Mean of the group without nightmares as opposed to the dorsal AHI Mean of the group with nightmares. Through this study we highlighted that excessive daytime sleepiness and snoring are prevalent symptoms in dorsal OSAHS. The presence of these symptoms in patients with sleep disorders may improve early diagnosis and the choice of an appropriate treatment for dorsal sleep apnea- hypopnea syndrome, thus participating in improving the patient’s life quality

  8. 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.

  9. An Unexpected Near Term Pregnancy in a Rudimentary Uterine Horn

    Directory of Open Access Journals (Sweden)

    Elisabete Gonçalves

    2013-01-01

    Full Text Available Unicornuate uterus occurs due to a complete or partial nondevelopment of one Mullerian duct; sometimes it is associated with a rudimentary horn, which can communicate or not with uterine cavity or contain functional endometrium. Pregnancy in a rudimentary horn is rare and the outcome almost always unfavorable, usually ending in rupture during the first or second trimester with significant morbidity and mortality. Despite the availability and advances on imagiologic procedures, recognition of this ectopic pregnancy is frequently made at laparotomy after abdominal pain and collapse. The authors describe a case of a primigravida with 34 weeks of gestation admitted with a preeclampsia with severity criteria. A cesarean for fetal malpresentation was done and, unexpectedly, a rudimentary horn pregnancy was found with a live newborn. In the literature, few reports of a horn pregnancy reaching the viability with a live newborn are described, enhancing the clinical importance of this case. A review of literature concerning the epidemics, clinical presentation, and appropriate management of uterine horn pregnancies is made.

  10. A case of dorsal oblique fingertip amputation.

    Science.gov (United States)

    Takeda, Shinsuke; Tatebe, Masahiro; Morita, Akimasa; Yoneda, Hidemasa; Iwatsuki, Katsuyuki; Hirata, Hitoshi

    2017-01-01

    This study reports successful finger replantation in a patient with a dorsal oblique fingertip amputation. When repairing this unique type of injury, an evaluation of the remaining vessels is more useful for successful replantation than the anatomical zone classification. We propose that Kasai's classification is appropriate for guiding treatment.

  11. A case of dorsal oblique fingertip amputation

    OpenAIRE

    Takeda, Shinsuke; Tatebe, Masahiro; Morita, Akimasa; Yoneda, Hidemasa; Iwatsuki, Katsuyuki; Hirata, Hitoshi

    2017-01-01

    Abstract This study reports successful finger replantation in a patient with a dorsal oblique fingertip amputation. When repairing this unique type of injury, an evaluation of the remaining vessels is more useful for successful replantation than the anatomical zone classification. We propose that Kasai?s classification is appropriate for guiding treatment.

  12. Neuroradiological evaluation of dorsal cyst malformations

    International Nuclear Information System (INIS)

    Utsunomiya, Hidetsuna; Hayashi, Takashi; Hashimoto, Takeo; Matsuishi, Toyojiro; Okudera, Toshio.

    1988-01-01

    We discussed six cases with dorsal cyst malformations listing their neuroradiological observations and proposed to differentiate between the holosphere and hemisphere as defined by Yokota (1984). The cases were divided into holospheric and hemispheric groups depending on the continuity of their frontal lobe midlines. Cases 1, 2 and 3 were placed in the holospheric group because of their unseparated frontal lobe sbeneath the partially formed anterior interhemispheric fissures. Cases 4, 5 and 6 were grouped in the hemisphere due to the completion of the interhemispheric fissures. There has been a tendency in recent years for most cases of cerebral malformations having an endogenous dorsal cyst with monoventricular configuration to be diagnosed as holoprosencephaly. However, we believe that only patients who have a dorsal cyst in the holospheric brain should be included, and the others in the hemispheric brain, which is capable of completing hemispheric cleavage, should not. Therefore, we emphasize the importance of correctly identifying the holospheric state in the dorsal cyst malformations for diagnosing holoprosencephaly. (author)

  13. Intracellular responses to frequency modulated tones in the dorsal cortex of the mouse inferior colliculus

    Directory of Open Access Journals (Sweden)

    Ruediger eGeis

    2013-01-01

    Full Text Available Frequency modulations occur in many natural sounds, including vocalizations. The neuronal response to frequency modulated (FM stimuli has been studied extensively in different brain areas, with an emphasis on the auditory cortex and the central nucleus of the inferior colliculus. Here, we measured the responses to FM sweeps in whole-cell recordings from neurons in the dorsal cortex of the mouse inferior colliculus. Both up- and downward logarithmic FM sweeps were presented at two different speeds to both the ipsi- and the contralateral ear. Based on the number of action potentials that were fired, between 10-24% of cells were selective for rate or direction of the FM sweeps. A somewhat lower percentage of cells, 6-21%, showed selectivity based on EPSP size. To study the mechanisms underlying the generation of FM selectivity, we compared FM responses with responses to simple tones in the same cells. We found that if pairs of neurons responded in a similar way to simple tones, they generally also responded in a similar way to FM sweeps. Further evidence that FM selectivity can be generated within the dorsal cortex was obtained by reconstructing FM sweeps from the response to simple tones using three different models. In about half of the direction selective neurons the selectivity was generated by spectrally asymmetric synaptic inhibition. In addition, evidence for direction selectivity based on the timing of excitatory responses was also obtained in some cells. No clear evidence for the local generation of rate selectivity was obtained. We conclude that FM direction selectivity can be generated within the dorsal cortex of the mouse inferior colliculus by multiple mechanisms.

  14. 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 ...

  15. Stimulus selectivity in dorsal and ventral prefrontal cortex after training in working memory tasks

    Science.gov (United States)

    Meyer, Travis; Qi, Xue-Lian; Stanford, Terrence R.; Constantinidis, Christos

    2011-01-01

    The prefrontal cortex is known to represent different types of information in working memory. Contrasting theories propose that the dorsal and ventral regions of the lateral prefrontal cortex are innately specialized for the representation of spatial and non-spatial information respectively (Goldman-Rakic, 1996), or that the two regions are shaped by the demands of cognitive tasks imposed on them (Miller, 2000). To resolve this issue, we recorded from neurons in the two regions, prior to and at multiple stages of training monkeys on visual working memory tasks. Prior to training, substantial functional differences were present between the two regions. Dorsal prefrontal cortex exhibited higher overall responsiveness to visual stimuli and higher selectivity for spatial information. After training, stimulus selectivity generally decreased, though dorsal prefrontal cortex retained higher spatial selectivity regardless of task performed. Ventral prefrontal cortex appeared to be affected to a greater extent by the nature of task performed. Our results indicate that regional specialization for stimulus selectivity is present in the primate prefrontal cortex regardless of training. Dorsal areas of the prefrontal cortex are inherently organized to represent spatial information and training has little influence on this spatial bias. Ventral areas are biased toward non-spatial information although they are more influenced by training both in terms of activation and changes in stimulus selectivity. PMID:21525266

  16. Functional Connectivity in the Left Dorsal Stream Facilitates Simultaneous Language Translation: an EEG Study

    Directory of Open Access Journals (Sweden)

    Stefan eElmer

    2016-02-01

    Full Text Available Cortical speech processing is dependent on the mutual interdependence of two distinctive processing streams supporting sound-to-meaning (i.e., ventral stream and sound-to-articulation (i.e., dorsal stream mapping. Here, we compared the strengths of intracranial functional connectivity between two main hubs of the dorsal stream, namely the left auditory-related cortex (ARC and Broca’s region, in a sample of simultaneous interpreters (SIs and multilingual control subjects while the participants performed a mixed and unmixed auditory semantic decision task. Under normal listening conditions such kind of tasks are known to initiate a spread of activation along the ventral stream. However, due to extensive and specific training, here we predicted that SIs will more strongly recruit the dorsal pathway in order to pre-activate the speech codes of the corresponding translation. In line with this reasoning, EEG results demonstrate increased left-hemispheric theta phase synchronization in SLI compared to multilingual control subjects during early task-related processing stages. In addition, within the SI group functional connectivity strength in the left dorsal pathway was positively related to the cumulative number of training hours across lifespan, and inversely correlated with the age of training commencement. Hence, we propose that the alignment of neuronal oscillations between brain regions involved in hearing and speaking results from an intertwining of training, sensitive period, and predisposition.

  17. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    Although it is well known that cisplatin causes a sensory neuropathy, the primary site of involvement is not established. The clinical symptoms localized in a stocking-glove distribution may be explained by a length dependent neuronopathy or by a distal axonopathy. To study whether the whole neuron...... nerve were 50-60% reduced, whereas no definite changes occurred at lower doses. The SNAP conduction velocities were reduced by 10-15% at cumulative doses of 400-700 mg/m2 consistent with loss of large myelinated fibres. SNAPs from primarily Pacinian corpuscles in digit 3 and the dorsolateral side...... of large dorsal root ganglion cells. Motor conduction studies, autonomic function and warm and cold temperature sensation remained unchanged at all doses of cisplatin treatment. The results of these studies are consistent with degeneration of large sensory neurons whereas there was no evidence of distal...

  18. Assembly techniques used in construction of neutrino horns at BNL

    International Nuclear Information System (INIS)

    Sims, W.P.; Carroll, A.; Leonhardt, W.

    1987-01-01

    This paper will describe the techniques used in the assembly of the neutrino focusing horns which were installed in the fast extracted beam at the Alternating Gradient Synchrotron. The horns are coaxial magnetic lenses that are pulsed to a maximum of 14 kV and 300 kA. The materials and techniques used are further complicated by the fact that the horn must survive in a high radiation environment. We will describe both the techniques and materials that were used in making the high current electrical connections. This will include the silver plating of aluminum, methods for handling thermal expansion and large magnetic forces, and the fabrication of rigid coaxial conductors. The techniques described in this paper can be used in the assembly of any pulsed high current device

  19. Assembly techniques used in construction of neutrino horns at BNL

    International Nuclear Information System (INIS)

    Sims, W.P.; Carroll, A.; Leonhardt, W.; Monaghan, R.; Pearson, C.; Pendzick, A.; Ryan, G.; Sandberg, J.; Smith, G.; Stillman, P.

    1987-01-01

    This paper describes the techniques used in the assembly of the neutrino focusing horns which were installed in the fast extracted beam at the Alternating Gradient Synchrotron. The horns are coaxial magnetic lenses that are pulsed to a maximum of 14 kV and 300 kA. The materials and techniques used are further complicated by the fact that the horn must survive in a high radiation environment. The authors describe both the techniques and materials that were used in making the high current electrical connections. This includes the silver plating of aluminum, methods for handling thermal expansion and large magnetic forces, and the fabrication of rigid coaxial conductors. The techniques described in this paper can be used in the assembly of any pulsed high current device

  20. Holocene Evolution and Sediment Provenance of Horn Island, Mississippi, USA

    Science.gov (United States)

    Schulze, N.; Wallace, D. J.; Miner, M. D.

    2017-12-01

    As one of the most stable islands in the Mississippi-Alabama barrier island chain, Horn Island provides critical habitat, plays an important role in regulating estuarine conditions in the Mississippi Sound, and helps to attenuate wave energy and storm surge for the mainland. The provenance of sediments comprising Horn Island is largely unknown and has implications for mode of island genesis and evolution. The existing literature proposes that island chain formation was initiated by bar emergence from a subaqueous spit that grew laterally westward from Dauphin Island in the east. Decelerating sea level rise 4,000 to 5,000 years ago facilitated island formation. This proposed mode of formation is supported by a lone radiocarbon date from lagoonal sediments below Horn Island, suggesting the system formed after 4,615 ± 215 years BP. Rivers supplying suspended sediment include the Mississippi, Pascagoula, Mobile and Apalachicola, but the variable nature of their paths and sediment supply means that Horn Island has received differing amounts of sediment from these proximal rivers throughout the Holocene. To analyze the stratigraphy and sediment characteristics of Horn Island, we will utilize 24 vibracores (up to 6 meters in length) from offshore Horn Island that were obtained by the United States Geological Survey (USGS) and 9 onshore drill cores (up to 28 meters in length) from the Mississippi Department of Environmental Quality. High-resolution LiDAR data collected by the National Oceanic and Atmospheric Administration in 2010 will be used to describe modern geomorphic barrier environments. We will employ down-core x-ray diffraction and x-ray fluorescence analyses to identify mineralogical and chemical signatures that potentially correspond to unique signatures of the fluvial sources of proximal rivers. New radiocarbon ages will be used to constrain the timing of island formation and alterations in sediment supply. High-resolution shallow geophysical data will provide

  1. Superficial dorsal vein injury/thrombosis presenting as false penile fracture requiring dorsal venous ligation.

    Science.gov (United States)

    Rafiei, Arash; Hakky, Tariq S; Martinez, Daniel; Parker, Justin; Carrion, Rafael

    2014-12-01

    Conditions mimicking penile fracture are extremely rare and have been seldom described. To describe a patient with false penile fracture who presented with superficial dorsal vein injury/thrombosis managed with ligation. A 33-year-old male presented with penile swelling and ecchymosis after intercourse. A penile ultrasound demonstrated a thrombosed superficial dorsal vein but also questionable fracture of the tunica albuginea. As the thrombus was expanding, he was emergently taken to the operating room for exploration and required only dorsal venous ligation. Postoperatively, patient's Sexual Health Inventory for Men score was 23, and he had no issues with erections or sexual intercourse. Early exploration of patients with suspected penile fracture provides excellent results with maintenance of erectile function. Also, in the setting of dorsal vein thrombosis, ligation preserves the integrity of the penile tissues and avoids unnecessary complications from conservative management. Rafiei A, Hakky TS, Martinez D, Parker J, and Carrion R. Superficial dorsal vein injury/thrombosis presenting as false penile fracture requiring dorsal venous ligation.

  2. Imaging neuronal pathways with 52Mn PET

    DEFF Research Database (Denmark)

    Napieczynska, Hanna; Severin, Gregory; Fonslet, Jesper

    2017-01-01

    Manganese in its divalent state (Mn2+) has features that make it a unique tool for tracing neuronal pathways. It is taken up and transported by neurons in an activity dependent manner and it can cross synapses. It also acts as a contrast agent for magnetic resonance imaging (MRI) enabling...... visualization of neuronal tracts. However, due to the limited sensitivity of MRI systems relatively high Mn2+ doses are required. This is undesirable, especially in long-term studies, because of the known toxicity of the metal. In order to overcome this limitation, we propose 52Mn as a positron emission...... tomography (PET) neuronal tract tracer. We used 52Mn for imaging dopaminergic pathways after a unilateral injection into the ventral tegmental area (VTA), as well as the striatonigral pathway after an injection into the dorsal striatum (STR) in rats. Furthermore, we tested potentially noxious effects...

  3. A ruptured rudimentary horn of a unicornuate uterus at 18 weeks ...

    African Journals Online (AJOL)

    76000 pregnancies. Rupture of the horn in pregnancy is considered the most serious and common complication of rudimentary horns. The investigation of choice is considered to be magnetic resonance imaging (MRI). Evaluation of renal tract ...

  4. 77 FR 47011 - Endangered and Threatened Wildlife and Plants; Reclassifying the Straight-Horned Markhor With...

    Science.gov (United States)

    2012-08-07

    ...; Reclassifying the Straight-Horned Markhor With Special Rule AGENCY: Fish and Wildlife Service, Interior. ACTION... reclassify the straight-horned markhor (Capra falconeri jerdoni) from endangered to threatened under the... the status of the straight-horned markhor. This proposal constitutes our 12-month finding on the...

  5. 9 CFR 95.12 - Bones, horns, and hoofs; importations permitted subject to restrictions.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Bones, horns, and hoofs; importations... ENTRY INTO THE UNITED STATES § 95.12 Bones, horns, and hoofs; importations permitted subject to restrictions. Bones, horns, and hoofs offered for importation which do not meet the conditions or requirements...

  6. Spontaneous Rupture of Gravid Horn of Bicornuate Uterus at Term ...

    African Journals Online (AJOL)

    We report a case of a 28 year old secondigravida with uterus bicornis unicollis who had spontaneous rupture of one of the uteri in pregnancy, had excision of one horn of the double uterus and was able to carry a subsequent pregnancy to term and achieve a live birth. The literature on double uterus was also reviewed.

  7. Littoral Encounters : The Shore as Cultural Interface in King Horn

    NARCIS (Netherlands)

    Sobecki, Sebastian

    2006-01-01

    1. III * Later Medieval: Excluding Chaucer -- Brown et al., 10.1093 ... ... between the Saracens and the londisse men allied to the protagonist (' Littoral Encounters: the Shore as Cultural Interface in King Horn', Al-Mas a ... www.ywes.oxfordjournals.org/cgi/content/full/man0092 2.Murray, Alan V.

  8. Acute Renal Failure Following the Saharan Horned Viper (Cerastes ...

    African Journals Online (AJOL)

    Introduction: The Saharan horned viper (Cerastes cerastes) is a common snake in the sandy and rocky regions in the south of Morocco. Although nearly all snakes with medical relevance can induce acute renal failure (ARF), it's unusual except with bites by some viper species. ARF has very rarely been reported following ...

  9. Marketing of hooves and horns in Maiduguri metropolitan area of ...

    African Journals Online (AJOL)

    Marketing of hooves and horns in Maiduguri metropolitan area of Borno State, Nigeria. M Goni, IM Sulumbe, M Sabo. Abstract. No Abstract. Global Journal of Agricultural Sciences Vol. 7 (1) 2008: pp.141-144. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  10. Ruptured rudimentary horn at 22 weeks | Dhar | Nigerian Medical ...

    African Journals Online (AJOL)

    ... horn pregnancy at 22 weeks presented to Nizwa regional referral hospital in shock with features of acute abdomen. Chances of rupture in first or second trimester are increased with catastrophic haemorrhage leading to increased maternal and perinatal morbidity and mortality. Management of such cases is a challenge till ...

  11. Toward a Regional Security Architecture for the Horn of Africa ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Moreover, conflict in one country tends to affect its neighbours, mainly through the flow of refugees and weapons. Building on work carried out during Phase I ... Extrants. Rapports. Towards Developing a Regional Security Architecture for the Horn of Africa: Developing Responses to Human (In) Security-Phase Two ...

  12. Generation of microbubbles from hollow cylindrical ultrasonic horn.

    Science.gov (United States)

    Makuta, Toshinori; Suzuki, Ryodai; Nakao, Takaaki

    2013-01-01

    In this study, we found that microbubbles with diameters of less than 100μm can be easily generated by using a hollow cylindrical ultrasonic horn. Consecutive images of bubbles obtained by using high-speed and high-resolution cameras reveal that a capillary wave is formed on the gas-liquid interface under weak ultrasonic irradiation and that the wave head is detached in the form of bubbles by the fragmentation of the interface as the power of ultrasonic irradiation increases. Moreover, consecutive images of the bubble interface obtained by an ultra-high-speed camera indicate that the breakup of bubbles oscillating harmonically with the ultrasonic irradiation generates many microbubbles that are less than 100μm in diameter. With regard to the orifice diameter of the horn end, we found that its optimum value varies with the ultrasonic power input. When the orifice diameter is small, the capillary wave generated from the horn end easily propagates all over the gas-liquid interface, thereby starting the generation of microbubbles at a lower ultrasonic power input. When the orifice diameter is large, the capillary wave is attenuated because of viscosity and surface tension. Hence, in this case, microbubble generation from the horn requires a higher ultrasonic power input. Furthermore, the maximum yield of microbubbles via primary and secondary bubble generation can be increased by increasing the gas flow rate. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Ion temperature profiles in the horns of the plasma sheet

    Science.gov (United States)

    Suszcynsky, D. M.; Gosling, J. T.; Thomsen, M. F.

    1993-01-01

    The plasma sheet horns are the low-altitude extensions of the plasma sheet that lie poleward of the plasmasphere and equatorward of the tail lobes. Within the horns, magnetic field lines of increasing geomagnetic latitudes map to increasing distances into the downtail plasma sheet. Plasma data from the fast plasma experiment on ISEE 2 have been analyzed for 11 outbound crossings of the horns in the premidnight sector of the magnetosphere at typical altitudes of 2-4 R(E). These crossings typically occurred on time scales of less than 1 hour, providing almost instantaneous snapshots of plasma gradients within the horns. Ion temperatures observed during these crossings generally decreased by a factor of four to eight as magnetic field lines of increasing geomagnetic latitude were traversed. If we make the reasonable assumption that the ion temperatures are constant along the field lines within the plasma sheet, then this result implies that the ion temperatures in the downtail plasma sheet also commonly decrease by this same factor over the radial range extending from the inner edge of the plasma sheet at the plasmapause boundary to the outer edge at a neutral line in the distant tail.

  14. Brain, memory and development : the imprint of Gabriel Horn

    NARCIS (Netherlands)

    Bolhuis, Johan J; Brown, Malcolm W; Johnson, Mark H

    2015-01-01

    This special issue of Neuroscience & Biobehavioral Reviews is dedicated to the memory of Sir Gabriel Horn, who died on 2nd August 2012. In his impressive career that spanned more than 50 years (Bolhuis and Johnson, 2012; Brown, 2013), Horn’s contributions to cognitive neuroscience consistently

  15. Book Review Winnicott's children By Ann Horn and Monica Lanyado ...

    African Journals Online (AJOL)

    Remember me, or Register. DOWNLOAD FULL TEXT Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. Book Review Winnicott's children. By Ann Horn and Monica Lanyado (2012). Rod Anderson. Abstract. Routledge, London and New York 206 pages. Paperback, ISBN 978-0-415-67291-7. ZAR 503.00

  16. Learning to recognize horn and whistle sounds for humanoid robots

    NARCIS (Netherlands)

    Backer, N.; Visser, A.

    2014-01-01

    The efficiency and accuracy of several state-of-the-art algorithms for real-time sound classification on a NAO robot are evaluated, to determine how accurate they are at distinguishing horn and whistle sounds in both optimal conditions, and a noisy environment. Each approach uses a distinct

  17. Response of False horn plantain to different plant densities and ...

    African Journals Online (AJOL)

    The study, which was carried out at the Crops Research Institute, Kumasi, Ghana, from April 1992 to March 1995, aimed at determining (i) the optimum plant density of False horn plantain for maximum yield, and (ii) the optimum frequency of handweeding for economic returns. Results indicated that the optimum plant density ...

  18. Past and future rainfall in the Horn of Africa.

    Science.gov (United States)

    Tierney, Jessica E; Ummenhofer, Caroline C; deMenocal, Peter B

    2015-10-01

    The recent decline in Horn of Africa rainfall during the March-May "long rains" season has fomented drought and famine, threatening food security in an already vulnerable region. Some attribute this decline to anthropogenic forcing, whereas others maintain that it is a feature of internal climate variability. We show that the rate of drying in the Horn of Africa during the 20th century is unusual in the context of the last 2000 years, is synchronous with recent global and regional warming, and therefore may have an anthropogenic component. In contrast to 20th century drying, climate models predict that the Horn of Africa will become wetter as global temperatures rise. The projected increase in rainfall mainly occurs during the September-November "short rains" season, in response to large-scale weakening of the Walker circulation. Most of the models overestimate short rains precipitation while underestimating long rains precipitation, causing the Walker circulation response to unrealistically dominate the annual mean. Our results highlight the need for accurate simulation of the seasonal cycle and an improved understanding of the dynamics of the long rains season to predict future rainfall in the Horn of Africa.

  19. Issues in treating depression in primary care | Horn | Continuing ...

    African Journals Online (AJOL)

    Issues in treating depression in primary care. NR Horn. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

  20. 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.

  1. Preferential loss of dorsal-hippocampus synapses underlies memory impairments provoked by short, multimodal stress.

    Science.gov (United States)

    Maras, P M; Molet, J; Chen, Y; Rice, C; Ji, S G; Solodkin, A; Baram, T Z

    2014-07-01

    The cognitive effects of stress are profound, yet it is unknown if the consequences of concurrent multiple stresses on learning and memory differ from those of a single stress of equal intensity and duration. We compared the effects on hippocampus-dependent memory of concurrent, hours-long light, loud noise, jostling and restraint (multimodal stress) with those of restraint or of loud noise alone. We then examined if differences in memory impairment following these two stress types might derive from their differential impact on hippocampal synapses, distinguishing dorsal and ventral hippocampus. Mice exposed to hours-long restraint or loud noise were modestly or minimally impaired in novel object recognition, whereas similar-duration multimodal stress provoked severe deficits. Differences in memory were not explained by differences in plasma corticosterone levels or numbers of Fos-labeled neurons in stress-sensitive hypothalamic neurons. However, although synapses in hippocampal CA3 were impacted by both restraint and multimodal stress, multimodal stress alone reduced synapse numbers severely in dorsal CA1, a region crucial for hippocampus-dependent memory. Ventral CA1 synapses were not significantly affected by either stress modality. Probing the basis of the preferential loss of dorsal synapses after multimodal stress, we found differential patterns of neuronal activation by the two stress types. Cross-correlation matrices, reflecting functional connectivity among activated regions, demonstrated that multimodal stress reduced hippocampal correlations with septum and thalamus and increased correlations with amygdala and BST. Thus, despite similar effects on plasma corticosterone and on hypothalamic stress-sensitive cells, multimodal and restraint stress differ in their activation of brain networks and in their impact on hippocampal synapses. Both of these processes might contribute to amplified memory impairments following short, multimodal stress.

  2. Preferential loss of dorsal-hippocampus synapses underlies memory impairments provoked by short, multimodal stress

    Science.gov (United States)

    Maras, P M; Molet, J; Chen, Y; Rice, C; Ji, S G; Solodkin, A; Baram, T Z

    2014-01-01

    The cognitive effects of stress are profound, yet it is unknown if the consequences of concurrent multiple stresses on learning and memory differ from those of a single stress of equal intensity and duration. We compared the effects on hippocampus-dependent memory of concurrent, hours-long light, loud noise, jostling and restraint (multimodal stress) with those of restraint or of loud noise alone. We then examined if differences in memory impairment following these two stress types might derive from their differential impact on hippocampal synapses, distinguishing dorsal and ventral hippocampus. Mice exposed to hours-long restraint or loud noise were modestly or minimally impaired in novel object recognition, whereas similar-duration multimodal stress provoked severe deficits. Differences in memory were not explained by differences in plasma corticosterone levels or numbers of Fos-labeled neurons in stress-sensitive hypothalamic neurons. However, although synapses in hippocampal CA3 were impacted by both restraint and multimodal stress, multimodal stress alone reduced synapse numbers severely in dorsal CA1, a region crucial for hippocampus-dependent memory. Ventral CA1 synapses were not significantly affected by either stress modality. Probing the basis of the preferential loss of dorsal synapses after multimodal stress, we found differential patterns of neuronal activation by the two stress types. Cross-correlation matrices, reflecting functional connectivity among activated regions, demonstrated that multimodal stress reduced hippocampal correlations with septum and thalamus and increased correlations with amygdala and BST. Thus, despite similar effects on plasma corticosterone and on hypothalamic stress-sensitive cells, multimodal and restraint stress differ in their activation of brain networks and in their impact on hippocampal synapses. Both of these processes might contribute to amplified memory impairments following short, multimodal stress. PMID:24589888

  3. Lentiviral gene transfer into the dorsal root ganglion of adult rats

    Directory of Open Access Journals (Sweden)

    Park Frank

    2011-08-01

    Full Text Available Abstract Background Lentivector-mediated gene delivery into the dorsal root ganglion (DRG is a promising method for exploring pain pathophysiology and for genetic treatment of chronic neuropathic pain. In this study, a series of modified lentivector particles with different cellular promoters, envelope glycoproteins, and viral accessory proteins were generated to evaluate the requirements for efficient transduction into neuronal cells in vitro and adult rat DRG in vivo. Results In vitro, lentivectors expressing enhanced green fluorescent protein (EGFP under control of the human elongation factor 1α (EF1α promoter and pseudotyped with the conventional vesicular stomatitis virus G protein (VSV-G envelope exhibited the best performance in the transfer of EGFP into an immortalized DRG sensory neuron cell line at low multiplicities of infection (MOIs, and into primary cultured DRG neurons at higher MOIs. In vivo, injection of either first or second-generation EF1α-EGFP lentivectors directly into adult rat DRGs led to transduction rates of 19 ± 9% and 20 ± 8% EGFP-positive DRG neurons, respectively, detected at 4 weeks post injection. Transduced cells included a full range of neuronal phenotypes, including myelinated neurons as well as both non-peptidergic and peptidergic nociceptive unmyelinated neurons. Conclusion VSV-G pseudotyped lentivectors containing the human elongation factor 1α (EF1α-EGFP expression cassette demonstrated relatively efficient transduction to sensory neurons following direct injection into the DRG. These results clearly show the potential of lentivectors as a viable system for delivering target genes into DRGs to explore basic mechanisms of neuropathic pain, with the potential for future clinical use in treating chronic pain.

  4. Horn fly (Diptera: Muscidae) saliva targets thrombin action in hemostasis.

    Science.gov (United States)

    Cupp, M S; Zhang, D; Cupp, E W

    2000-05-01

    The horn fly, Hematobia irritans (L.), is an important pest of livestock because the adult stage of both sexes are aggressive blood-feeders. Remarkably, even though horn fly adults feed recurrently on their hosts as ectoparasites, these flies lack the ADP-responsive antiplatelet aggregation and vasodilatory antihemostatic systems described for other blood-feeding Diptera. Horn fly salivary gland extracts do interfere with the normal coagulation process as demonstrated by the recalcification time assay. Using this as a baseline, the effects of saliva on recalcification time, activated partial thromboplastin time, prothrombin time, and thrombin time were measured to determine which arm(s) of the coagulation cascade might be impacted. Factor-deficient plasma assays also were used to measure possible perturbations in clotting. Gland-free saliva delayed the recalcification time as well as the activated partial thromboplastin time, prothrombin time, and thrombin time. Saliva also further delayed clotting times of plasmas deficient in factor V, factor VIII, and factor XIII, indicating that other factors in the coagulation cascade were inhibited. Although horn fly saliva did not alter the ability of deficient plasma reconstituted with factor X to clot, it did inhibit deficient plasma reconstituted with factor II (thrombin). Antithrombin activity in saliva was confirmed by its ability to interfere with thrombin hydrolysis of fibrinogen, its normal substrate, and by its inhibition of thrombin action on a chromagenic substrate that mimics the hydrolytic site of fibrinogen. Thus, horn fly saliva contains a factor that specifically targets thrombin, a key component in the coagulation cascade. While the biochemical mechanisms of inhibition may vary, this antihemostatic characteristic is shared with other zoophilic Diptera such as black flies, Simulium spp., and tsetse, Glossina morsitans morsitans Westwood, that feed on ungulates.

  5. Upregulation of the dorsal raphe nucleus-prefrontal cortex serotonin system by chronic treatment with escitalopram in hyposerotonergic Wistar-Kyoto rats

    NARCIS (Netherlands)

    Yamada, Makiko; Kawahara, Yukie; Kaneko, Fumi; Kishikawa, Yuki; Sotogaku, Naoki; Poppinga, Wilfred J.; Folgering, Joost H. A.; Dremencov, Eliyahu; Kawahara, Hiroshi; Nishi, Akinori

    Wistar-Kyoto (WKY) rats are sensitive to chronic stressors and exhibit depression-like behavior. Dorsal raphe nucleus (DRN) serotonin (5-HT) neurons projecting to the prefrontal cortex (PFC) comprise the important neurocircuitry underlying the pathophysiology of depression. To evaluate the DRN-PFC

  6. Carcinoma Buccal Mucosa Underlying a Giant Cutaneous Horn: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2014-01-01

    Full Text Available Cutaneous horn is a conical, dense, and hyperkeratotic protrusion that often appears similar to the horn of an animal. Giant cutaneous horns are rare; no incidence or prevalence has been reported. The significance of cutaneous horns is that they occur in association with, or as a response to, a wide variety of underlying benign, premalignant, and malignant cutaneous diseases. A case of giant cutaneous horn of left oral commissure along with carcinoma left buccal mucosa is reported here as an extremely rare oral/perioral pathology.

  7. Horn clause verification with convex polyhedral abstraction and tree automata-based refinement

    DEFF Research Database (Denmark)

    Kafle, Bishoksan; Gallagher, John Patrick

    2017-01-01

    In this paper we apply tree-automata techniques to refinement of abstract interpretation in Horn clause verification. We go beyond previous work on refining trace abstractions; firstly we handle tree automata rather than string automata and thereby can capture traces in any Horn clause derivations...... underlying the Horn clauses. Experiments using linear constraint problems and the abstract domain of convex polyhedra show that the refinement technique is practical and that iteration of abstract interpretation with tree automata-based refinement solves many challenging Horn clause verification problems. We...... compare the results with other state-of-the-art Horn clause verification tools....

  8. Tree automata-based refinement with application to Horn clause verification

    DEFF Research Database (Denmark)

    Kafle, Bishoksan; Gallagher, John Patrick

    2015-01-01

    In this paper we apply tree-automata techniques to refinement of abstract interpretation in Horn clause verification. We go beyond previous work on refining trace abstractions; firstly we handle tree automata rather than string automata and thereby can capture traces in any Horn clause derivations...... underlying the Horn clauses. Experiments using linear constraint problems and the abstract domain of convex polyhedra show that the refinement technique is practical and that iteration of abstract interpretation with tree automata-based refinement solves many challenging Horn clause verification problems. We...... compare the results with other state of the art Horn clause verification tools....

  9. Optogenetic inhibition of dorsal medial prefrontal cortex attenuates stress-induced reinstatement of palatable food seeking in female rats.

    Science.gov (United States)

    Calu, Donna J; Kawa, Alex B; Marchant, Nathan J; Navarre, Brittany M; Henderson, Mark J; Chen, Billy; Yau, Hau-Jie; Bossert, Jennifer M; Schoenbaum, Geoffrey; Deisseroth, Karl; Harvey, Brandon K; Hope, Bruce T; Shaham, Yavin

    2013-01-02

    Relapse to maladaptive eating habits during dieting is often provoked by stress. Recently, we identified a role of dorsal medial prefrontal cortex (mPFC) neurons in stress-induced reinstatement of palatable food seeking in male rats. It is unknown whether endogenous neural activity in dorsal mPFC drives stress-induced reinstatement in female rats. Here, we used an optogenetic approach, in which female rats received bilateral dorsal mPFC microinjections of viral constructs coding light-sensitive eNpHR3.0-eYFP or control eYFP protein and intracranial fiber optic implants. Rats were food restricted and trained to lever press for palatable food pellets. Subsequently, pellets were removed, and lever pressing was extinguished; then the effect of bilateral dorsal mPFC light delivery on reinstatement of food seeking was assessed after injections of the pharmacological stressor yohimbine (an α-2 andrenoceptor antagonist) or pellet priming, a manipulation known to provoke food seeking in hungry rats. Dorsal mPFC light delivery attenuated yohimbine-induced reinstatement of food seeking in eNpHR3.0-injected but not eYFP-injected rats. This optical manipulation had no effect on pellet-priming-induced reinstatement or ongoing food-reinforced responding. Dorsal mPFC light delivery attenuated yohimbine-induced Fos immunoreactivity and disrupted neural activity during in vivo electrophysiological recording in awake rats. Optical stimulation caused significant outward currents and blocked electrically evoked action potentials in eNpHR3.0-injected but not eYFP-injected mPFC hemispheres. Light delivery alone caused no significant inflammatory response in mPFC. These findings indicate that intracranial light delivery in eNpHR3.0 rats disrupts endogenous dorsal mPFC neural activity that plays a role in stress-induced relapse to food seeking in female rats.

  10. The expression of contextual fear conditioning involves activation of a NMDA receptor-nitric oxide-cGMP pathway in the dorsal hippocampus of rats.

    Science.gov (United States)

    Fabri, Denise R S; Hott, Sara C; Reis, Daniel G; Biojone, Caroline; Corrêa, Fernando M A; Resstel, Leonardo B M

    2014-10-01

    The dorsal portion of the hippocampus is a limbic structure that is involved in fear conditioning modulation in rats. Moreover, evidence shows that the local dorsal hippocampus glutamatergic system, nitric oxide (NO) and cGMP modulate behavioral responses during aversive situations. Therefore, the present study investigated the involvement of dorsal hippocampus NMDA receptors and the NO/cGMP pathway in contextual fear conditioning expression. Male Wistar rats were submitted to an aversive contextual conditioning session and 48 h later they were re-exposed to the aversive context in which freezing, cardiovascular responses (increase of both arterial pressure and heart rate) and decrease of tail temperature were recorded. The intra-dorsal hippocampus administration of the NMDA receptor antagonist AP7, prior to the re-exposure to the aversive context, attenuated fear-conditioned responses. The re-exposure to the context evoked an increase in NO concentration in the dorsal hippocampus of conditioned animals. Similar to AP7 administration, we observed a reduction of contextual fear conditioning after dorsal hippocampus administration of either the neuronal NO synthase inhibitor N-propyl-L-arginine, the NO scavenger c-PTIO or the guanylate cyclase inhibitor ODQ. Therefore, the present findings suggest the possible existence of a dorsal hippocampus NMDA/NO/cGMP pathway modulating the expression of contextual fear conditioning in rats. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

  11. Harbour porpoises on Horns Reef - Effects of the Horns Reef wind farm. Annual status report 2004

    International Nuclear Information System (INIS)

    Tougaard, J.; Carstensen, J.; Wisz, M.S.; Teilmann, J.; Bech, N.I.; Skov, H.; Henriksen, Oluf D.

    2005-01-01

    This report describes the monitoring of harbour porpoises at Horns Reef Offshore Wind Farm, Denmark, with emphasis on data collected in 2004. Three 2-day surveys with line transect observations of porpoises were conducted in 2004 and data from acoustic data loggers (TPODs) were collected from January through July. Although new data from 2004 was included in the analysis there were no significant additions to conclusions from previous years' reports. On the contrary, the general conclusions regarding effects of construction and operation of the wind farm on porpoise abundance inside and outside the wind farm area have been weakened somewhat compared to previous reports. The specific conclusions regarding short-time effects of construction activities (especially pile drivings) has not been changed, however. Modelling of the spatial distribution of porpoises in the area demonstrated very weak correlations with static environmental variables (water depth, change in water depth and distance to 6 m depth contour). This highlights the importance of dynamic environmental variables, in particular tide and salinity, in determining the fine-scale distribution of porpoises and their prey in the area. a strong correlation between tide and porpoise abundance observed in the T-POD data on some parts of the reef (high abundance at high tide, low at low tide) supports the importance of this variable. Tide and salinity will be included in a forthcoming analysis of the entire dataset from the monitoring program. (au)

  12. Harbour porpoises on Horns Reef - Effects of the Horns Reef wind farm. Annual status report 2003

    International Nuclear Information System (INIS)

    Tougaard, J.; Carstensen, J.; Henriksen, Oluf. D.; Teilmann, J.; Rye Hansen, J.

    2004-06-01

    Occurrence and distribution of harbour porpoises (Phocoena phocoena) in and around the off-shore wind farm on Horns Reef, Denmark, was investigated. This report describes data collected in 2003 as part of an ongoing monitoring program, covering a period before construction of the wind farm (baseline), the construction period in 2002 and one year following construction of the wind farm. Data from acoustic dataloggers (T-PODs) and visual surveys conducted from ships confirmed the presence of harbour porpoises inside the wind farm area during all periods investigated. Comparison with baseline data from 1999-2001 and with control areas outside the wind farm did not show a statistical significant change in sighting rates inside the wind farm area in the first year following construction relative to baseline. T-POD data showed a pronounced effect of the construction of the wind farm on the indicators 'encounter duration' (measure of how long porpoises remain close to the POD) and 'waiting time' (measure of time interval between porpoise encounters). Both parameters seem to indicate higher levels of porpoise activity during construction (encounter duration went up, waiting time went down) compared to baseline. A partial return to baseline levels was seen for these two indicators in 2003. (au)

  13. Harbour porpoises on Horns Reef - Effects of the Horns Reef wind farm. Annual status report 2003

    Energy Technology Data Exchange (ETDEWEB)

    Tougaard, J.; Carstensen, J.; Henriksen, Oluf. D.; Teilmann, J. [National Environmental Research Inst., Roskilde (Denmark); Rye Hansen, J. [DDH Consulting A/S, Roskilde (Denmark)

    2004-06-15

    Occurrence and distribution of harbour porpoises (Phocoena phocoena) in and around the off-shore wind farm on Horns Reef, Denmark, was investigated. This report describes data collected in 2003 as part of an ongoing monitoring program, covering a period before construction of the wind farm (baseline), the construction period in 2002 and one year following construction of the wind farm. Data from acoustic dataloggers (T-PODs) and visual surveys conducted from ships confirmed the presence of harbour porpoises inside the wind farm area during all periods investigated. Comparison with baseline data from 1999-2001 and with control areas outside the wind farm did not show a statistical significant change in sighting rates inside the wind farm area in the first year following construction relative to baseline. T-POD data showed a pronounced effect of the construction of the wind farm on the indicators 'encounter duration' (measure of how long porpoises remain close to the POD) and 'waiting time' (measure of time interval between porpoise encounters). Both parameters seem to indicate higher levels of porpoise activity during construction (encounter duration went up, waiting time went down) compared to baseline. A partial return to baseline levels was seen for these two indicators in 2003. (au)

  14. Harbour porpoises on Horns Reef - Effects of the Horns Reef wind farm. Annual status report 2004

    Energy Technology Data Exchange (ETDEWEB)

    Tougaard, J.; Carstensen, J.; Wisz, M.S.; Teilmann, J.; Bech, N.I. [National Environmental Res. Inst., Roskilde (Denmark); Skov, H. [DHI - Water and Environment, Hoersholm (Denmark); Henriksen, Oluf, D. [DDH-Consulting A/S, Roskilde (Denmark)

    2005-07-15

    This report describes the monitoring of harbour porpoises at Horns Reef Offshore Wind Farm, Denmark, with emphasis on data collected in 2004. Three 2-day surveys with line transect observations of porpoises were conducted in 2004 and data from acoustic data loggers (TPODs) were collected from January through July. Although new data from 2004 was included in the analysis there were no significant additions to conclusions from previous years' reports. On the contrary, the general conclusions regarding effects of construction and operation of the wind farm on porpoise abundance inside and outside the wind farm area have been weakened somewhat compared to previous reports. The specific conclusions regarding short-time effects of construction activities (especially pile drivings) has not been changed, however. Modelling of the spatial distribution of porpoises in the area demonstrated very weak correlations with static environmental variables (water depth, change in water depth and distance to 6 m depth contour). This highlights the importance of dynamic environmental variables, in particular tide and salinity, in determining the fine-scale distribution of porpoises and their prey in the area. a strong correlation between tide and porpoise abundance observed in the T-POD data on some parts of the reef (high abundance at high tide, low at low tide) supports the importance of this variable. Tide and salinity will be included in a forthcoming analysis of the entire dataset from the monitoring program. (au)

  15. The Cancer Chemotherapeutic Paclitaxel Increases Human and Rodent Sensory Neuron Responses to TRPV1 by Activation of TLR4

    Czech Academy of Sciences Publication Activity Database

    Li, Y.; Adámek, Pavel; Zhang, H.; Tatsui, C. E.; Rhines, L. D.; Mrózková, Petra; Li, Q.; Kosturakis, A. K.; Cassidy, R. M.; Harrison, D. S.; Cata, J. P.; Sapire, K.; Zhang, HM.; Kennamer-Chapman, R. M.; Jawad, A. B.; Ghetti, A.; Yan, J.; Paleček, Jiří; Dougherty, P. M.

    2015-01-01

    Roč. 35, č. 39 (2015), s. 13487-13500 ISSN 0270-6474 R&D Projects: GA MŠk(CZ) LH12058; GA MŠk(CZ) EE2.3.30.0025; GA ČR(CZ) GA15-11138S Institutional support: RVO:67985823 Keywords : cancer * dorsal horn * DRG * neuropathy Subject RIV: FH - Neurology Impact factor: 5.924, year: 2015

  16. Identification of microorganisms in partially fed female horn flies, Haematobia irritans.

    Science.gov (United States)

    Torres, Lorena; Almazán, Consuelo; Ayllón, Nieves; Galindo, Ruth C; Rosario-Cruz, Rodrigo; Quiroz-Romero, Héctor; Gortazar, Christian; de la Fuente, José

    2012-09-01

    The horn fly Haematobia irritans (Linnaeus, 1758) (Diptera: Muscidae) is one of the most important ectoparasites of cattle. The parasitism of horn flies interferes with cattle feeding, thus reducing weight gain and milk production. Additionally, horn flies are mechanical vectors of pathogens that cause disease in cattle. The aims of this study were to identify microorganisms in partially fed female horn flies through mining of expressed sequence tags (ESTs) and to characterize microorganism prevalence using real-time RT-PCR. Seven unigenes containing 24 ESTs were homologous to infectious agents. Microorganisms identified in partially fed female horn flies ESTs included Nora virus (3 unigenes; 8 ESTs), Wolbachia endosymbionts (3 unigenes; 3 ESTs), and Mycobacterium bovis (1 unigene; 13 ESTs). These results expanded the repertoire of microorganisms that could cause persistent infections or be mechanically transmitted by horn flies and support further studies on the role of horn flies in the epidemiology of these pathogens in Mexico.

  17. Ruptured Noncommunicating Rudimentary Horn Pregnancy at 19 Weeks with Previous Cesarean Delivery: A Case Report

    Directory of Open Access Journals (Sweden)

    Sita Thakur

    2012-01-01

    Full Text Available Unicornuate uterus with noncommunicating rudimentary horn occurs due to incomplete fusion of mullerian ducts. Pregnancy in this horn is a rare phenomenon usually resulting in rupture during second trimester of pregnancy. Prerupture diagnosis of pregnancy in rudimentary horn with ultrasonography is technically difficult, with sensitivity of 30%. We report a case of ruptured non-communicating rudimentary horn at 19 weeks in a woman with previous Cesarean delivery. She had a routine malformation scan in which diagnosis was missed. Later she presented to emergency in shock, with massive hemoperitoneum and ruptured horn. So a high index of suspicion is required to save this catastrophic event and associated maternal morbidity and mortality. In our opinion, routine excision of rudimentary horn should be undertaken during nonpregnant state laparoscopically. However, those women who refuse should be adequately counseled regarding potential complications and if pregnancy occurs in rudimentary horn, first trimester laparoscopic excision should be done.

  18. [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.

  19. Differentiating lower motor neuron syndromes.

    Science.gov (United States)

    Garg, Nidhi; Park, Susanna B; Vucic, Steve; Yiannikas, Con; Spies, Judy; Howells, James; Huynh, William; Matamala, José M; Krishnan, Arun V; Pollard, John D; Cornblath, David R; Reilly, Mary M; Kiernan, Matthew C

    2017-06-01

    Lower motor neuron (LMN) syndromes typically present with muscle wasting and weakness and may arise from pathology affecting the distal motor nerve up to the level of the anterior horn cell. A variety of hereditary causes are recognised, including spinal muscular atrophy, distal hereditary motor neuropathy and LMN variants of familial motor neuron disease. Recent genetic advances have resulted in the identification of a variety of disease-causing mutations. Immune-mediated disorders, including multifocal motor neuropathy and variants of chronic inflammatory demyelinating polyneuropathy, account for a proportion of LMN presentations and are important to recognise, as effective treatments are available. The present review will outline the spectrum of LMN syndromes that may develop in adulthood and provide a framework for the clinician assessing a patient presenting with predominantly LMN features. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. 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.

  1. Milk production traits of beef cows as affected by horn fly count and sire breed type.

    Science.gov (United States)

    Mays, A R; Brown, M A; von Tunglen, D L; Rosenkrans, C F

    2014-03-01

    Horn fly infestations negatively impact economic traits of beef cattle. Our objective was to determine the impact of horn flies on beef cattle milk yield and quality. Cows (n = 53) were derived from Brangus dams and sired by Bonsmara (n = 7), Brangus (n = 13), Charolais (n = 8), Gelbvieh (n = 5), Hereford (n = 12), and Romosinuano (n = 8) bulls. Horn fly counts and estimates of milk yield and quality were recorded monthly from May through October on individual cows. Data for milk yield and quality and horn fly count were analyzed by mixed model least squares using a linear model including sire breed, cow in sire breed, month, and month × sire breed. Effects of horn fly count on milk yield and quality were estimated by analysis of covariance using log horn fly count and log horn fly count × sire breed. Horn fly counts varied by month (P flies) and peaked in August (520 flies). Bonsmara and Gelbvieh sired cows had greater (P fly count differed (P horn fly count in Gelbvieh and Bonsmara sired cows. Regression coefficient for milk yield on log horn fly count was reduced (P fly count were associated with decreases (P fly numbers depending on month of lactation and interaction with log horn fly count. In May, June, and July milk yield was reduced 0.72, 0.68, and 0.71 kg/d per unit increase in log horn fly count. Our results indicate that horn fly infestations reduce milk yield and quality of spring-calving beef cows depending on sire breed and month of lactation. Development of sustainable beef production systems may include selecting breed types whose milk yield and quality is less influenced by horn flies, allowing for better expression of genetic potential for milk yield in nutritionally challenging environments.

  2. Dorsal forearm muscles: US anatomy Pictorial Essay

    Science.gov (United States)

    Precerutti, M.; Garioni, E.; Ferrozzi, G.

    2010-01-01

    The dorsal compartment of the forearm contains nine muscles: four belong to the superficial group (extensor digitorum communis, extensor digiti minimi, extensor carpi ulnaris and anconeus) and five to the deep group (supinator, abductor longus, extensor pollicis brevis, extensor pollicis longus, and extensor indices). Of these nine muscles the following details are considered: origin, course, distal insertion and their anatomical connection with those structures which are most often affected by pathologies. The radiologist must have a thorough knowledge of this complex topographic anatomy in order to perform ultrasound (US) and magnetic resonance imaging (MRI) examinations and correctly interpret the images. PMID:23396199

  3. Representation of pheromones, interspecific signals, and plant odors in higher olfactory centers; mapping physiologically identified antennal-lobe projection neurons in the male heliothine moth

    Directory of Open Access Journals (Sweden)

    Xin-Cheng eZhao

    2014-10-01

    Full Text Available In the primary olfactory centre of the moth brain, for example, a few enlarged glomeruli situated dorsally, at the entrance of the antennal nerve, are devoted to information about female-produced substances whereas a set of more numerous ordinary glomeruli receives input about general odorants. Heliothine moths are particularly suitable for studying central chemosensory mechanisms not only because of their anatomically separated systems for plant odours and pheromones but also due to their use of female-produced substances in communication across the species. Thus, the male-specific system of heliothine moths includes two sub arrangements, one ensuring attraction and mating behavior by carrying information about pheromones released by conspecifics, and the other reproductive isolation via signal information emitted from heterospecifics. Based on previous tracing experiments, a general chemotopic organization of the male-specific glomeruli has been demonstrated in a number of heliothine species. As compared to the well explored organization of the moth antennal lobe, demonstrating a non-overlapping representation of the biologically relevant stimuli, less is known about the neural arrangement residing at the following synaptic level, i.e. the mushroom body calyces and the lateral horn. In the study presented here, we have labelled physiologically characterized antennal-lobe projection neurons in males of the two heliothine species, Heliothis virescens and Helicoverpa assulta, for the purpose of mapping their target regions in the protocerebrum. In order to compare the representation of plant odours, pheromones, and interspecific signals in the higher brain regions of each species, we have created standard brain atlases and registered three-dimensional models of distinct uniglomerular projection neuron types into the relevant atlas.

  4. Lack of GDAP1 induces neuronal calcium and mitochondrial defects in a knockout mouse model of charcot-marie-tooth neuropathy.

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    Manuela Barneo-Muñoz

    2015-04-01

    Full Text Available Mutations in GDAP1, which encodes protein located in the mitochondrial outer membrane, cause axonal recessive (AR-CMT2, axonal dominant (CMT2K and demyelinating recessive (CMT4A forms of Charcot-Marie-Tooth (CMT neuropathy. Loss of function recessive mutations in GDAP1 are associated with decreased mitochondrial fission activity, while dominant mutations result in impairment of mitochondrial fusion with increased production of reactive oxygen species and susceptibility to apoptotic stimuli. GDAP1 silencing in vitro reduces Ca2+ inflow through store-operated Ca2+ entry (SOCE upon mobilization of endoplasmic reticulum (ER Ca2+, likely in association with an abnormal distribution of the mitochondrial network. To investigate the functional consequences of lack of GDAP1 in vivo, we generated a Gdap1 knockout mouse. The affected animals presented abnormal motor behavior starting at the age of 3 months. Electrophysiological and biochemical studies confirmed the axonal nature of the neuropathy whereas histopathological studies over time showed progressive loss of motor neurons (MNs in the anterior horn of the spinal cord and defects in neuromuscular junctions. Analyses of cultured embryonic MNs and adult dorsal root ganglia neurons from affected animals demonstrated large and defective mitochondria, changes in the ER cisternae, reduced acetylation of cytoskeletal α-tubulin and increased autophagy vesicles. Importantly, MNs showed reduced cytosolic calcium and SOCE response. The development and characterization of the GDAP1 neuropathy mice model thus revealed that some of the pathophysiological changes present in axonal recessive form of the GDAP1-related CMT might be the consequence of changes in the mitochondrial network biology and mitochondria-endoplasmic reticulum interaction leading to abnormalities in calcium homeostasis.

  5. 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:

  6. Activation of neurokinin-1 receptors increases the excitability of guinea pig dorsal root ganglion cells.

    Science.gov (United States)

    Zhang, Xiulin; Pietra, Claudio; Lovati, Emanuela; de Groat, William C

    2012-10-01

    The suppression of overactive bladder symptoms in patients and overactive bladder reflexes in animal models by neurokinin (NK)-1 receptor antagonists raises the possibility that these drugs target sensory neurons. This mechanism was evaluated by examining the interactions between a specific NK-1 agonist, [Sar(9),Met(O(2))(11)]-substance P (Sar-Met-SP), and a potent NK-1 antagonist, netupitant (NTP), on small size (20-30 μm) dissociated L6 and S1 dorsal root ganglion (DRG) neurons from female guinea pigs. Current-clamp recording revealed that Sar-Met-SP (1 μM) elicited membrane depolarization (average 8.05 ± 1.38 mV) in 27% (18 of 65) of DRG neurons. In 74% of the remaining neurons (35 of 47) Sar-Met-SP decreased the rheobase for action potential (AP) generation and increased the response to a suprathreshold stimulus (3 times rheobase) without changing the membrane potential. Sar-Met-SP also induced changes in the action potential (AP) wave form, including 1) an increase in overshoot (average 5 mV, n = 35 neurons), 2) a prolongation of AP duration (from 4.64 to 5.29 ms, n = 34), and 3) a reduction in the maximal rate of AP repolarization. NTP (200 nM) reversed the Sar-Met-SP-induced changes. Ca(2+) imaging showed that application of Sar-Met-SP (1 μM) decreased the tachyphylaxis induced by repeated application of capsaicin (0.5 μM), an effect blocked by pretreatment with NTP (200 nM). These results raise the possibility that activation of NK-1 receptors in primary sensory neurons plays a role in the generation of overactive bladder and that block of NK-1 receptors in these neurons may contribute to efficacy of NK-1 antagonists in the treatment of overactive bladder symptoms.

  7. CRISPR Epigenome Editing of AKAP150 in DRG Neurons Abolishes Degenerative IVD-Induced Neuronal Activation.

    Science.gov (United States)

    Stover, Joshua D; Farhang, Niloofar; Berrett, Kristofer C; Gertz, Jason; Lawrence, Brandon; Bowles, Robby D

    2017-09-06

    Back pain is a major contributor to disability and has significant socioeconomic impacts worldwide. The degenerative intervertebral disc (IVD) has been hypothesized to contribute to back pain, but a better understanding of the interactions between the degenerative IVD and nociceptive neurons innervating the disc and treatment strategies that directly target these interactions is needed to improve our understanding and treatment of back pain. We investigated degenerative IVD-induced changes to dorsal root ganglion (DRG) neuron activity and utilized CRISPR epigenome editing as a neuromodulation strategy. By exposing DRG neurons to degenerative IVD-conditioned media under both normal and pathological IVD pH levels, we demonstrate that degenerative IVDs trigger interleukin (IL)-6-induced increases in neuron activity to thermal stimuli, which is directly mediated by AKAP and enhanced by acidic pH. Utilizing this novel information on AKAP-mediated increases in nociceptive neuron activity, we developed lentiviral CRISPR epigenome editing vectors that modulate endogenous expression of AKAP150 by targeted promoter histone methylation. When delivered to DRG neurons, these epigenome-modifying vectors abolished degenerative IVD-induced DRG-elevated neuron activity while preserving non-pathologic neuron activity. This work elucidates the potential for CRISPR epigenome editing as a targeted gene-based pain neuromodulation strategy. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  8. The Onecut Transcription Factors Regulate Differentiation and Distribution of Dorsal Interneurons during Spinal Cord Development

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    Karolina U. Kabayiza

    2017-05-01

    Full Text Available During embryonic development, the dorsal spinal cord generates numerous interneuron populations eventually involved in motor circuits or in sensory networks that integrate and transmit sensory inputs from the periphery. The molecular mechanisms that regulate the specification of these multiple dorsal neuronal populations have been extensively characterized. In contrast, the factors that contribute to their diversification into smaller specialized subsets and those that control the specific distribution of each population in the developing spinal cord remain unknown. Here, we demonstrate that the Onecut transcription factors, namely Hepatocyte Nuclear Factor-6 (HNF-6 (or OC-1, OC-2 and OC-3, regulate the diversification and the distribution of spinal dorsal interneuron (dINs. Onecut proteins are dynamically and differentially distributed in spinal dINs during differentiation and migration. Analyzes of mutant embryos devoid of Onecut factors in the developing spinal cord evidenced a requirement in Onecut proteins for proper production of a specific subset of dI5 interneurons. In addition, the distribution of dI3, dI5 and dI6 interneuron populations was altered. Hence, Onecut transcription factors control genetic programs that contribute to the regulation of spinal dIN diversification and distribution during embryonic development.

  9. Identification of genes differentially expressed in dorsal and ventral chick midbrain during early development.

    Science.gov (United States)

    Chittka, A; Volff, Jn; Wizenmann, A

    2009-04-27

    During the development of the central nervous system (CNS), patterning processes along the dorsoventral (DV) axis of the neural tube generate different neuronal subtypes. As development progresses these neurons are arranged into functional units with varying cytoarchitecture, such as laminae or nuclei for efficient relaying of information. Early in development ventral and dorsal regions are similar in size and structure. Different proliferation rates and cell migration patterns are likely to result in the formation of laminae or nuclei, eventually. However, the underlying molecular mechanisms that establish these different structural arrangements are not well understood.We undertook a differential display polymerase chain reaction (DD-PCR) screen to identify genes with distinct expression patterns between dorsal and ventral regions of the chick midbrain in order to identify genes which regulate the sculpturing of such divergent neuronal organisation. We focused on the DV axis of the early chick midbrain since mesencephalic alar plate and basal plate develop into laminae and nuclei, respectively. We identified 53 differentially expressed bands in our initial screen. Twenty-six of these could be assigned to specific genes and we could unambiguously show the differential expression of five of the isolated cDNAs in vivo by in situ mRNA expression analysis. Additionally, we verified differential levels of expression of a selected number of genes by using reverse transcriptase (RT) PCR method with gene-specific primers.One of these genes, QR1, has been previously cloned and we present here a detailed study of its early developmental time course and pattern of expression providing some insights into its possible function. Our phylogenetic analysis of QR1 shows that it is the chick orthologue of Sparc-like 1/Hevin/Mast9 gene in mice, rats, dogs and humans, a protein involved in cell adhesion. This study reveals some possible networks, which might be involved in directing

  10. 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

  11. Runx transcription factors in neuronal development

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    Shiga Takashi

    2008-08-01

    Full Text Available Abstract Runt-related (Runx transcription factors control diverse aspects of embryonic development and are responsible for the pathogenesis of many human diseases. In recent years, the functions of this transcription factor family in the nervous system have just begun to be understood. In dorsal root ganglion neurons, Runx1 and Runx3 play pivotal roles in the development of nociceptive and proprioceptive sensory neurons, respectively. Runx appears to control the transcriptional regulation of neurotrophin receptors, numerous ion channels and neuropeptides. As a consequence, Runx contributes to diverse aspects of the sensory system in higher vertebrates. In this review, we summarize recent progress in determining the role of Runx in neuronal development.