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Sample records for cord dorsal horn

  1. [Subpopulation of calbindin-immunoreactive interneurons in the dorsal horn of the mice spinal cord].

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    Porseva, V V; Shilkin, V V; Strelkov, A A; Masliukov, P M

    2014-01-01

    In the dorsal horn of the spinal cord in the plates I-IV on the thoracic and lumbar levels different subpopulations of interneurons immunoreactive for calbindin 28 kDa (CAB IR), which are specific to each plate. In the area of the medial edge of the dorsal horn, we have found a special subpopulation of CAB IR interneurons whose morphometric characteristics differ from CAB IR interneurons subpopulations of said plates. The number of CAB IR interneurons was maximal in the plate II at all levels of the spinal cord. Leveled differences are more CAB IR interneurons and larger area of the cross sections at the lumbar level.

  2. Inhibition of spinal cord dorsal horn neuronal activity by electrical stimulation of the cerebellar cortex.

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    Hagains, Christopher E; Senapati, Arun K; Huntington, Paula J; He, Ji-Wei; Peng, Yuan B

    2011-11-01

    The cerebellum plays a major role in not only modulating motor activity, but also contributing to other functions, including nociception. The intermediate hemisphere of the cerebellum receives sensory input from the limbs. With the extensive connection between the cerebellum to brain-stem structures and cerebral cortex, it is possible that the cerebellum may facilitate the descending system to modulate spinal dorsal horn activity. This study provided the first evidence to support this hypothesis. Thirty-one wide-dynamic-range neurons from the left lumbar and 27 from the right lumbar spinal dorsal horn were recorded in response to graded mechanical stimulation (brush, pressure, and pinch) at the hind paws. Electrical stimulation of the cerebellar cortex of the left intermediate hemisphere significantly reduced spinal cord dorsal horn neuron-evoked responses bilaterally in response to peripheral high-intensity mechanical stimuli. It is concluded that the cerebellum may play a potential antinociceptive role, probably through activating descending inhibitory pathways indirectly.

  3. Expression of nerve growth factor in spinal dorsal horn following crushed spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    AIM: The aim of this study was to explore the expression of nerve growth factor(NGF) in spinal dorsal horn following crushed spinal cord injury. METHODS: The adult Srague-Dawley rat model of crushed spinal cord injury was established by the method in our laboratory, and intact spinal cord was used as control. The rats were sacrificed respectively after 24 hours, 7 days, and 21 days of operation, and the L3 spinal segments were removed out and fixed in 4% polyformaldehyde. The segments were sectioned into sections of 20 μm in thickness. The sections were stained with anti-NGF antibody by ABC method of immunohistochemistry technique. The immunoreactive intensity of NGF and the number of positive neurons as well as glial cells in dorsal horn were observed and counted under light microscope. RESULTS: The number of positive cells and immunoreactive intensity of NGF increased gradually in the dorsal horn at 24 hours, 7 days and 21 days following crushed spinal cord injury compared with control group (P<0.01). CONCLUSION: These results indicated that NGF plays an important role in the postoperative reaction during the early period of the crushed spinal cord injury.

  4. Inward currents induced by ischemia in rat spinal cord dorsal horn neurons

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    Gu Jianguo G

    2007-04-01

    Full Text Available Abstract Hypoxia and ischemia occur in the spinal cord when blood vessels of the spinal cord are compressed under pathological conditions such as spinal stenosis, tumors, and traumatic spinal injury. Here by using spinal cord slice preparations and patch-clamp recordings we investigated the influence of an ischemia-simulating medium on dorsal horn neurons in deep lamina, a region that plays a significant role in sensory hypersensitivity and pathological pain. We found that the ischemia-simulating medium induced large inward currents in dorsal horn neurons recorded. The onset of the ischemia-induced inward currents was age-dependent, being onset earlier in older animals. Increases of sensory input by the stimulation of afferent fibers with electrical impulses or by capsaicin significantly speeded up the onset of the ischemia-induced inward currents. The ischemia-induced inward currents were abolished by the glutamate receptor antagonists CNQX (20 μM and APV (50 μM. The ischemia-induced inward currents were also substantially inhibited by the glutamate transporter inhibitor TBOA (100 μM. Our results suggest that ischemia caused reversal operation of glutamate transporters, leading to the release of glutamate via glutamate transporters and the subsequent activation of glutamate receptors in the spinal dorsal horn neurons.

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

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    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...

  6. Electrophysiological characterization of spontaneous recovery in deep dorsal horn interneurons after incomplete spinal cord injury.

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    Rank, M M; Flynn, J R; Galea, M P; Callister, R; Callister, R J

    2015-09-01

    In the weeks and months following an incomplete spinal cord injury (SCI) significant spontaneous recovery of function occurs in the absence of any applied therapeutic intervention. The anatomical correlates of this spontaneous plasticity are well characterized, however, the functional changes that occur in spinal cord interneurons after injury are poorly understood. Here we use a T10 hemisection model of SCI in adult mice (9-10 wks old) combined with whole-cell patch clamp electrophysiology and a horizontal spinal cord slice preparation to examine changes in intrinsic membrane and synaptic properties of deep dorsal horn (DDH) interneurons. We made these measurements during short-term (4 wks) and long-term (10 wks) spontaneous recovery after SCI. Several important intrinsic membrane properties are altered in the short-term, but recover to values resembling those of uninjured controls in the longer term. AP discharge patterns are reorganized at both short-term and long-term recovery time points. This is matched by reorganization in the expression of voltage-activated potassium and calcium subthreshold-currents that shape AP discharge. Excitatory synaptic inputs onto DDH interneurons are significantly restructured in long-term SCI mice. Plots of sEPSC peak amplitude vs. rise times suggest considerable dendritic expansion or synaptic reorganization occurs especially during long-term recovery from SCI. Connectivity between descending dorsal column pathways and DDH interneurons is reduced in the short-term, but amplified in long-term recovery. Our results suggest considerable plasticity in both intrinsic and synaptic mechanisms occurs spontaneously in DDH interneurons following SCI and takes a minimum of 10 wks after the initial injury to stabilize.

  7. Extracellular glutamate in the dorsal horn of the lumbar spinal cord in the freely moving rat during hindlimb stepping.

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    Walwyn, W M; Ta-Haung, J; Ackerson, L; Maidment, N T; Edgerton, V R

    1999-08-01

    The capacity to reestablish locomotor function after complete spinal cord transection in the adult mammal is now well documented. Further studies have shown different neurotransmitters to be involved in the initiation and maintenance of these locomotor patterns. However, there has been no in vivo evidence of the changes in glutamate or any other neurotransmitter in the extracellular space of the dorsal horn during an alternating motor pattern such as hindlimb stepping. This study describes an in vivo microdialysis technique to measure extracellular glutamate in the dorsal horn of the spinal cord in the fully awake intact rat. A concentric microdialysis probe was placed in the dorsal horn at L5, and 18 h later dialysate samples were collected at 20-min intervals before, during, and after 20 min of hindlimb stepping. During stepping, extracellular glutamate rose 150% above resting levels and returned to resting levels 40 min later. This increase may have occurred either as a result of primary afferent depolarization or modulation by the descending and ascending supraspinal pathways. In another series of experiments extracellular glutamate was, therefore, measured in the dorsal horn of the chronic spinally transected rat during 20 min of hindlimb stepping. Although the spinal group did not take as many steps as the intact group, those taking more than 40 steps showed a significant rise in extracellular glutamate, and the number of steps taken by the individual spinal rats correlated positively with the individual values of extracellular glutamate (r2 = 0.63). These results are consistent with glutamate being an important neurotransmitter in the spinal cord in normal locomotion.

  8. Intersegmental synchronization of spontaneous activity of dorsal horn neurons in the cat spinal cord.

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    Manjarrez, E; Jiménez, I; Rudomin, P

    2003-02-01

    Extracellular recordings of neuronal activity made in the lumbosacral spinal segments of the anesthetized cat have disclosed the existence of a set of neurons in Rexed's laminae III-VI that discharged in a highly synchronized manner during the occurrence of spontaneous negative cord dorsum potentials (nCDPs) and responded to stimulation of low-threshold cutaneous fibers (<1.5x T) with mono- and polysynaptic latencies. The cross-correlation between the spontaneous discharges of pairs of synchronic neurons was highest when they were close to each other, and decreased with increasing longitudinal separation. Simultaneous recordings of nCDPs from several segments in preparations with the peripheral nerves intact have disclosed the existence of synchronized spontaneous nCDPs in segments S1-L4. These potentials lasted between 25 and 70 ms and were usually larger in segments L7-L5, where they attained amplitudes between 50 and 150 micro V. The transection of the intact ipsilateral hindlimb cutaneous and muscle nerves, or the section of the dorsal columns between the L5 and L6, or between the L6 and L7 segments in preparations with already transected nerves, had very small effects on the intersegmental synchronization of the spontaneous nCDPs and on the power spectra of the cord dorsum potentials recorded in the lumbosacral enlargement. In contrast, sectioning the ipsilateral dorsal horn and the dorsolateral funiculus at these segmental levels strongly decoupled the spontaneous nCDPs generated rostrally from those generated caudally to the lesion and reduced the magnitude of the power spectra throughout the whole frequency range. These results indicate that the lumbosacral intersegmental synchronization between the spontaneous nCDPs does not require sensory inputs and is most likely mediated by intra- and intersegmental connections. It is suggested that the occurrence of spontaneous synchronized nCDPs is due to the activation of tightly coupled arrays of neurons, each

  9. Pulsed electrical stimulation protects neurons in the dorsal root and anterior horn of the spinal cord after peripheral nerve injury.

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    Pei, Bao-An; Zi, Jin-Hua; Wu, Li-Sheng; Zhang, Cun-Hua; Chen, Yun-Zhen

    2015-10-01

    Most studies on peripheral nerve injury have focused on repair at the site of injury, but very few have examined the effects of repair strategies on the more proximal neuronal cell bodies. In this study, an approximately 10-mm-long nerve segment from the ischial tuberosity in the rat was transected and its proximal and distal ends were inverted and sutured. The spinal cord was subjected to pulsed electrical stimulation at T10 and L3, at a current of 6.5 mA and a stimulation frequency of 15 Hz, 15 minutes per session, twice a day for 56 days. After pulsed electrical stimulation, the number of neurons in the dorsal root ganglion and anterior horn was increased in rats with sciatic nerve injury. The number of myelinated nerve fibers was increased in the sciatic nerve. The ultrastructure of neurons in the dorsal root ganglion and spinal cord was noticeably improved. Conduction velocity of the sciatic nerve was also increased. These results show that pulsed electrical stimulation protects sensory neurons in the dorsal root ganglia as well as motor neurons in the anterior horn of the spinal cord after peripheral nerve injury, and that it promotes the regeneration of peripheral nerve fibers.

  10. Inhibitory coupling between inhibitory interneurons in the spinal cord dorsal horn

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    Ribeiro-da-Silva Alfredo

    2009-05-01

    Full Text Available Abstract Local inhibitory interneurons in the dorsal horn play an important role in the control of excitability at the segmental level and thus determine how nociceptive information is relayed to higher structures. Regulation of inhibitory interneuron activity may therefore have critical consequences on pain perception. Indeed, disinhibition of dorsal horn neuronal networks disrupts the balance between excitation and inhibition and is believed to be a key mechanism underlying different forms of pain hypersensitivity and chronic pain states. In this context, studying the source and the synaptic properties of the inhibitory inputs that the inhibitory interneurons receive is important in order to predict the impact of drug action at the network level. To address this, we studied inhibitory synaptic transmission in lamina II inhibitory interneurons identified under visual guidance in spinal slices taken from transgenic mice expressing enhanced green fluorescent protein (EGFP under the control of the GAD promoter. The majority of these cells fired tonically to a long depolarizing current pulse. Monosynaptically evoked inhibitory postsynaptic currents (eIPSCs in these cells were mediated by both GABAA and glycine receptors. Consistent with this, both GABAA and glycine receptor-mediated miniature IPSCs were recorded in all of the cells. These inhibitory inputs originated at least in part from local lamina II interneurons as verified by simultaneous recordings from pairs of EGFP+ cells. These synapses appeared to have low release probability and displayed potentiation and asynchronous release upon repeated activation. In summary, we report on a previously unexamined component of the dorsal horn circuitry that likely constitutes an essential element of the fine tuning of nociception.

  11. Exercise alleviates hypoalgesia and increases the level of calcitonin gene-related peptide in the dorsal horn of the spinal cord of diabetic rats

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    Patrícia Severo do Nascimento

    2012-09-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the effects of treadmill training on nociceptive sensitivity and immunoreactivity to calcitonin gene-related peptide in the dorsal horn of the spinal cord of diabetic rats. METHODS: Male Wistar rats were divided into three groups: control, diabetic and trained diabetic. Treadmill training was performed for 8 weeks. The blood glucose concentrations and body weight were evaluated 48 h after diabetes induction and every 30 days thereafter. The nociceptive sensitivity was evaluated using the tail-flick apparatus. The animals were then transcardially perfused, and the spinal cords were post-fixed, cryoprotected and sectioned in a cryostat. Immunohistochemistry for calcitonin gene-related peptide analysis was performed on the dorsal horn of the spinal cord. RESULTS: The nociceptive sensitivity analysis revealed that, compared with the control and trained diabetic animals, the latency to tail deflection on the apparatus was longer for the diabetic animals. Optical densitometry demonstrated decreased calcitonin gene-related peptide immunoreactivity in the dorsal horn of the spinal cord in diabetic animals, which was reversed by treadmill training. CONCLUSION: We concluded that treadmill training can alleviate nociceptive hypoalgesia and reverse decreased calcitonin gene-related peptide immunoreactivity in the dorsal horn of the spinal cord of diabetic animals without pharmacological treatment.

  12. Bursting deep dorsal horn neurons: The pharmacological target for the anti-spastic effects of Zolmitriptan?

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    Rasmussen, Rune; Carlsen, Eva Maria Meier

    2016-01-01

    In a recent publication, Thaweerattanasinp and colleagues investigated spinal cord injury and firing properties of deep dorsal horn neurons during NMDA or Zolmitriptan application by employing electrophysiology in an in vitro spinal cord preparation. Deep dorsal horn neurons were classified...

  13. Effect of propofol on glutamate-induced activation and elated inflammatory cytokines of astrocytes from spinal cord dorsal horn

    Institute of Scientific and Technical Information of China (English)

    Chengming Qin; Qing Li; Juying Liu; Tao Zhu; Yong Xiang

    2008-01-01

    BACKGROUND: Astrocytes participate in central nervous system-mediated physiological or pathological processes, such as pain. Activated dorsal horn astrocytes from the spinal cord produce nerve active substances and proinflammatory cytokines, such as interleukin-I beta (IL-1 β ), IL-6, and tumor necrosis factor-a (TNF-a ), which play important roles in pain transduction and regulation. OBJECTIVE: To investigate the effects of different doses of propofol on activation of cultured spinal cord dorsal horn astrocytes induced by glutamate, as well as changes in IL-1 β, IL-6, and TNF-a, and IL-10 (anti-inflammatory cytokine) expression in rats, and to explore the dose relationship of propofnl. DESIGN, TIME AND SETTING: The cellular and molecular biology experiment was performed at the Central Laboratory of Yunyang Medical College between March 2006 and December 2007. MATERIALS: Forty healthy, Wistar rats, aged 2-3 days, were selected. Propofol was provided by Zeneca, UK; glutamate by Sigma, USA; EPICS XL flow cytometry by Beckman culture, USA; rabbit-anti-mouse glial fibrillary acidic protein (GFAP) antibody kit and inflammatory cytokine detection kit were provided by Zhongshan Biotechnology Company Ltd., Beijing; multimedia color pathologic image analysis system was a product of Nikon, Japan. METHODS: Astrocytes were harvested from T11-L6spinal cord dorsal horn of Wistar rats and incubated for 3 weeks. The cells were divided into seven groups, according to various treatment conditions: control group was cells cultured in Hank's buffered saline solution; intralipid group was cells cultured in intralipid (0.2 mL/L); glutamate group was cells cultured with 100 μ mol/L glutamate; propofol group was cells cultured with 250 μ mol/L propofol; three glutamate plus propofol groups were cultured in 100 μ mol/L of glutamate, followed by 5, 25, and 250 μ mol/L of prnpofol 10 minutes later. MAIN OUTCOME MEASURES: GFAP-labeled astrocytes were analyzed using a multimedia

  14. In vivo characterization of colorectal and cutaneous inputs to lumbosacral dorsal horn neurons in the mouse spinal cord.

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    Farrell, K E; Rank, M M; Keely, S; Brichta, A M; Graham, B A; Callister, R J

    2016-03-01

    Chronic abdominal pain is a common symptom of inflammatory bowel disease and often persists in the absence of gut inflammation. Although the mechanisms responsible for ongoing pain are unknown, clinical and preclinical evidence suggests lumbosacral spinal cord dorsal horn neurons contribute to these symptoms. At present, we know little about the intrinsic and synaptic properties of this population of neurons in either normal or inflammed conditions. Therefore, we developed an in vivo preparation to make patch-clamp recordings from superficial dorsal horn (SDH) neurons receiving colonic inputs in naïve male mice. Recordings were made in the lumbosacral spinal cord (L6-S1) under isoflurane anesthesia. Noxious colorectal distension (CRD) was used to determine whether SDH neurons received inputs from mechanical stimulation/distension of the colon. Responses to hind paw/tail cutaneous stimulation and intrinsic and synaptic properties were also assessed, as well as action potential discharge properties. Approximately 11% of lumbosacral SDH neurons in the cohort of neurons sampled responded to CRD and a majority of these responses were subthreshold. Most CRD-responsive neurons (80%) also responded to cutaneous stimuli, compared with <50% of CRD-non-responsive neurons. Furthermore, CRD-responsive neurons had more hyperpolarized resting membrane potentials, larger rheobase currents, and reduced levels of excitatory drive, compared to CRD-non-responsive neurons. Our results demonstrate that CRD-responsive neurons can be distinguished from CRD-non-responsive neurons by several differences in their membrane properties and excitatory synaptic inputs. We also demonstrate that SDH neurons with colonic inputs show predominately subthreshold responses to CRD and exhibit a high degree of viscerosomatic convergence.

  15. Functional changes in deep dorsal horn interneurons following spinal cord injury are enhanced with different durations of exercise training

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    Rank, M M; Flynn, J R; Battistuzzo, C R; Galea, M P; Callister, R; Callister, R J

    2015-01-01

    Following incomplete spinal cord injury (SCI), collaterals sprout from intact and injured axons in the vicinity of the lesion. These sprouts are thought to form new synaptic contacts that effectively bypass the lesion epicentre and contribute to improved functional recovery. Such anatomical changes are known to be enhanced by exercise training; however, the mechanisms underlying exercise-mediated plasticity are poorly understood. Specifically, we do not know how SCI alone or SCI combined with exercise alters the intrinsic and synaptic properties of interneurons in the vicinity of a SCI. Here we use a hemisection model of incomplete SCI in adult mice and whole-cell patch-clamp recording in a horizontal spinal cord slice preparation to examine the functional properties of deep dorsal horn (DDH) interneurons located in the vicinity of a SCI following 3 or 6 weeks of treadmill exercise training. We examined the functional properties of local and descending excitatory synaptic connections by recording spontaneous excitatory postsynaptic currents (sEPSCs) and responses to dorsal column stimulation, respectively. We find that SCI in untrained animals exerts powerful effects on intrinsic, and especially, synaptic properties of DDH interneurons. Plasticity in intrinsic properties was most prominent at 3 weeks post SCI, whereas synaptic plasticity was greatest at 6 weeks post injury. Exercise training did not markedly affect intrinsic membrane properties; however, local and descending excitatory synaptic drive were enhanced by 3 and 6 weeks of training. These results suggest exercise promotes synaptic plasticity in spinal cord interneurons that are ideally placed to form new intraspinal circuits after SCI. PMID:25556804

  16. Spinal cord stimulation-induced analgesia: electrical stimulation of dorsal column and dorsal roots attenuates dorsal horn neuronal excitability in neuropathic rats.

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    Guan, Yun; Wacnik, Paul W; Yang, Fei; Carteret, Alene F; Chung, Chih-Yang; Meyer, Richard A; Raja, Srinivasa N

    2010-12-01

    The sites of action and cellular mechanisms by which spinal cord stimulation reduces neuropathic pain remain unclear. We examined the effect of bipolar electrical-conditioning stimulation (50 Hz, 0.2 ms, 5 min) of the dorsal column and lumbar dorsal roots on the response properties of spinal wide dynamic range (WDR) neurons in rats after L5 spinal nerve injury. The conditioning stimulation intensity was set at the lowest current that evoked a peak antidromic sciatic Aα/β-compound action potential without inducing an Aδ- or C-compound action potential. Within 15 min of the dorsal column or root conditioning stimulation, the spontaneous activity rate of WDR neurons was significantly reduced in nerve-injured rats. Conditioning stimulation also significantly attenuated WDR neuronal responses to mechanical stimuli in nerve-injured rats and inhibited the C-component of the neuronal response to graded intracutaneous electrical stimuli applied to the receptive field in nerve-injured and sham-operated rats. It is noteworthy that dorsal column stimulation blocked windup of WDR neuronal response to repetitive intracutaneous electrical stimulation (0.5 Hz) in nerve-injured and sham-operated rats, whereas dorsal root stimulation inhibited windup only in sham-operated rats. Therefore, stimulation of putative spinal substrates at A-fiber intensities with parameters similar to those used by patients with spinal cord stimulators attenuated established WDR neuronal hyperexcitability in the neuropathic condition and counteracted activity-dependent increase in neuronal excitability (i.e., windup). These results suggest a potential cellular mechanism underlying spinal cord stimulation-induced pain relief. This in vivo model allows the neurophysiologic basis for spinal cord stimulation-induced analgesia to be studied.

  17. Altered acetylcholinesterase levels in the spinal cord anterior horn and dorsal root ganglion following sciatic nerve ischemia

    Institute of Scientific and Technical Information of China (English)

    Zhenjun Yang; Pei Wang; Songhe Yang; Jingfeng Xue

    2009-01-01

    BACKGROUND: Peripheral nerve ischemia has been shown to result in ischemic fiber degeneration and axoplasmic transport disturbance. However, the effect on acetylcholinesterase (AChE) expression in relevant cells following sciatic nerve ischemia remains unclear. OBJECTIVE: To observe AChE concentration changes following peripheral nerve ischemia. DESIGN, TIME AND SETTING: The present comparative observation, neuroanatomical experiment was performed at the Central Laboratory Animal of Chengde Medical College between 2006 and 2007. MATERIALS: A total of 20 healthy, adult, Wistar rats were randomized into two groups (n = 10): 8-day ischemia and 14-day ischemia. METHODS: Ischemia injury was induced in the unilateral sciatic nerve (experimental side) through ligation of the common iliac artery. The contralateral side received no intervention, and served as the control side. Rats in the 8-day ischemia and 14-day ischemia groups were allowed to survive for 8 and 14 days, respectively. MAIN OUTCOME MEASURES: The L5 lumbar spinal cord and the L5 dorsal root ganglion were removed from both sides and sectioned utilizing a Leica vibrating slicer. AChE cellular expression was detected using Karnovsky-Root, and the number of AChE-positive cells and average gray value were analyzed using a MiVnt image analysis system. RESULTS: In the 8-day ischemia group, AChE-positive cell numbers were significantly less in the dorsal root ganglion and spinal cord anterior horn of the experimental side, but the average gray value was significantly greater, compared with the control side (P < 0.05). These changes were more significant in the 14-day ischemia group than in the 8-day ischemia group (P < 0.01). CONCLUSION: Peripheral nerve ischemia leads to decreased AChE expression in the associated cells in a time-dependent manner.

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

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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

  19. Distinct forms of synaptic inhibition and neuromodulation regulate calretinin-positive neuron excitability in the spinal cord dorsal horn.

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    Smith, K M; Boyle, K A; Mustapa, M; Jobling, P; Callister, R J; Hughes, D I; Graham, B A

    2016-06-21

    The dorsal horn (DH) of the spinal cord contains a heterogenous population of neurons that process incoming sensory signals before information ascends to the brain. We have recently characterized calretinin-expressing (CR+) neurons in the DH and shown that they can be divided into excitatory and inhibitory subpopulations. The excitatory population receives high-frequency excitatory synaptic input and expresses delayed firing action potential discharge, whereas the inhibitory population receives weak excitatory drive and exhibits tonic or initial bursting discharge. Here, we characterize inhibitory synaptic input and neuromodulation in the two CR+ populations, in order to determine how each is regulated. We show that excitatory CR+ neurons receive mixed inhibition from GABAergic and glycinergic sources, whereas inhibitory CR+ neurons receive inhibition, which is dominated by glycine. Noradrenaline and serotonin produced robust outward currents in excitatory CR+ neurons, predicting an inhibitory action on these neurons, but neither neuromodulator produced a response in CR+ inhibitory neurons. In contrast, enkephalin (along with selective mu and delta opioid receptor agonists) produced outward currents in inhibitory CR+ neurons, consistent with an inhibitory action but did not affect the excitatory CR+ population. Our findings show that the pharmacology of inhibitory inputs and neuromodulator actions on CR+ cells, along with their excitatory inputs can define these two subpopulations further, and this could be exploited to modulate discrete aspects of sensory processing selectively in the DH.

  20. Changes in correlation between spontaneous activity of dorsal horn neurones lead to differential recruitment of inhibitory pathways in the cat spinal cord.

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    Chávez, D; Rodríguez, E; Jiménez, I; Rudomin, P

    2012-04-01

    Simultaneous recordings of cord dorsum potentials along the lumbo-sacral spinal cord of the anaesthetized cat revealed the occurrence of spontaneous synchronous negative (n) and negative-positive (np) cord dorsum potentials (CDPs). The npCDPs, unlike the nCDPs, appeared preferentially associated with spontaneous negative dorsal root potentials (DRPs) resulting from primary afferent depolarization. Spontaneous npCDPs recorded in preparations with intact neuroaxis or after spinalization often showed a higher correlation than the nCDPs recorded from the same pair of segments. The acute section of the sural and superficial peroneal nerves further increased the correlation between paired sets of npCDPs and reduced the correlation between the nCDPs recorded from the same pair of segments. It is concluded that the spontaneous nCDPs and npCDPs are produced by the activation of interconnected sets of dorsal horn neurones located in Rexed's laminae III–IV and bilaterally distributed along the lumbo-sacral spinal cord. Under conditions of low synchronization in the activity of this network of neurones there would be a preferential activation of the intermediate nucleus interneurones mediating Ib non-reciprocal postsynaptic inhibition. Increased synchronization in the spontaneous activity of this ensemble of dorsal horn neurones would recruit the interneurones mediating primary afferent depolarization and presynaptic inhibition and, at the same time, reduce the activation of pathways mediating Ib postsynaptic inhibition. Central control of the synchronization in the spontaneous activity of dorsal horn neurones and its modulation by cutaneous inputs is envisaged as an effective mechanism for the selection of alternative inhibitory pathways during the execution of specific motor or sensory tasks.

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

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    Jo, Seung; Danscher, Gorm; Schrøder, Henrik

    2008-01-01

    to neuropathic pain we applied Chung's rodent pain model on BALB/c mice, and traced zinc transporter 3 (ZnT3) proteins and zinc ions with immunohistochemistry and autometallography (AMG), respectively. Under anesthesia the left fifth lumbar spinal nerve was ligated in male mice in order to produced neuropathic......Zinc enriched (ZEN) neurons and terminals are abundant in the rodent spinal cord. Zinc ions have been suggested to modulate the excitability of primary afferent fibers believed to be important in nociceptive transmission. To test the hypothesis that vesicular zinc concentration is related...... of the smaller spinal ganglion cell, but 5 days after spinal nerve transection zinc precipitation was also found in the lager ganglion cells. The present results indicate that zinc may be involved in pain mechanism in the spinal ganglion level. These results support the hypothesis that vesicular zinc might have...

  2. Actions of endomorphins on synaptic transmission of Adelta-fibers in spinal cord dorsal horn neurons.

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    Yajiri, Y; Huang, L Y

    2000-01-01

    The effects of endogenous mu-opioid ligands, endomorphins, on Adelta-afferent-evoked excitatory postsynaptic currents (EPSCs) were studied in substantia gelatinosa neurons in spinal cord slices. Under voltage-clamp conditions, endomorphins blocked the evoked EPSCs in a dose-dependent manner. To determine if the block resulted from changes in transmitter release from glutamatergic synaptic terminals, the opioid actions on miniature excitatory postsynaptic currents (mEPSCs) were examined. Endomorphins (1 microM) reduced the frequency but not the amplitude of mEPSCs, suggesting that endomorphins directly act on presynaptic terminals. The effects of endomorphins on the unitary (quantal) properties of the evoked EPSCs were also studied. Endomorphins reduced unitary content without significantly changing unitary amplitude. These results suggest that in addition to presynaptic actions on interneurons, endomorphins also inhibit evoked EPSCs by reducing transmitter release from Adelta-afferent terminals.

  3. Parcellation of cerebellins 1, 2, and 4 among different subpopulations of dorsal horn neurons in mouse spinal cord.

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    Cagle, Michael C; Honig, Marcia G

    2014-02-01

    The cerebellins (Cblns) are a family of secreted proteins that are widely expressed throughout the nervous system, but whose functions have been studied only in the cerebellum and striatum. Two members of the family, Cbln1 and Cbln2, bind to neurexins on presynaptic terminals and to GluRδs postsynaptically, forming trans-synaptic triads that promote synapse formation. Cbln1 has a higher binding affinity for GluRδs and exhibits greater synaptogenic activity than Cbln2. In contrast, Cbln4 does not form such triads and its function is unknown. The different properties of the three Cblns suggest that each plays a distinct role in synapse formation. To begin to elucidate Cbln function in other neuronal systems, we used in situ hybridization to examine Cbln expression in the mouse spinal cord. We find that neurons expressing Cblns 1, 2, and 4 tend to occupy different laminar positions within the dorsal spinal cord, and that Cbln expression is limited almost exclusively to excitatory neurons. Combined in situ hybridization and immunofluorescent staining shows that Cblns 1, 2, and 4 are expressed by largely distinct neuronal subpopulations, defined in part by sensory input, although there is some overlap and some individual neurons coexpress two Cblns. Our results suggest that differences in connectivity between subpopulations of dorsal spinal cord neurons may be influenced by which Cbln each subpopulation contains. Competitive interactions between axon terminals may determine the number of synapses each forms in any given region, and thereby contribute to the development of precise patterns of connectivity in the dorsal gray matter.

  4. Clinically relevant concentration of pregabalin has no acute inhibitory effect on excitation of dorsal horn neurons under normal or neuropathic pain conditions: An intracellular calcium-imaging study in spinal cord slices from adult rats.

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    Baba, Hiroshi; Petrenko, Andrey B; Fujiwara, Naoshi

    2016-10-01

    Pregabalin is thought to exert its therapeutic effect in neuropathic pain via binding to α2δ-1 subunits of voltage-gated calcium (Ca(2+)) channels. However, the exact analgesic mechanism after its binding to α2δ-1 subunits remains largely unknown. Whether a clinical concentration of pregabalin (≈10μM) can cause acute inhibition of dorsal horn neurons in the spinal cord is controversial. To address this issue, we undertook intracellular Ca(2+)-imaging studies using spinal cord slices with an intact attached L5 dorsal root, and examined if pregabalin acutely inhibits the primary afferent stimulation-evoked excitation of dorsal horn neurons in normal rats and in rats with streptozotocin-induced painful diabetic neuropathy. Under normal conditions, stimulation of a dorsal root evoked Ca(2+) signals predominantly in the superficial dorsal horn. Clinically relevant (10μM) and a very high concentration of pregabalin (100μM) did not affect the intensity or spread of dorsal root stimulation-evoked Ca(2+) signals, whereas an extremely high dose of pregabalin (300μM) slightly but significantly attenuated Ca(2+) signals in normal rats and in diabetic neuropathic (DN) rats. There was no difference between normal rats and DN rats with regard to the extent of signal attenuation at all concentrations tested. These results suggest that the activity of dorsal horn neurons in the spinal cord is not inhibited acutely by clinical doses of pregabalin under normal or DN conditions. It is very unlikely that an acute inhibitory action in the dorsal horn is the main analgesic mechanism of pregabalin in neuropathic pain states. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Effects of spinal and peripheral nerve lesions on the intersegmental synchronization of the spontaneous activity of dorsal horn neurons in the cat lumbosacral spinal cord.

    Science.gov (United States)

    García, C A; Chávez, D; Jiménez, I; Rudomin, P

    2004-05-06

    In the anesthetized and paralyzed cat, spontaneous negative cord dorsum potentials (nCDPs) appeared synchronously in the L3 to S1 segments, both ipsi- and contralaterally. The acute section of both the intact sural and the superficial peroneal nerve increased the variability of the spontaneous nCDPs without affecting their intersegmental coupling. On the other hand, the synchronization between the spontaneous nCDPs recorded in segments L5-L6 was strongly reduced following an interposed lesion of the left (ipsilateral) dorsolateral spinal quadrant and it was almost completely abolished by an additional lesion of the contralateral dorsolateral quadrant at the same level. Our observations support the existence of a system of spontaneously active dorsal horn neurons that is bilaterally distributed along the lumbosacral segments and affects, in a synchronized and organized manner, impulse transmission along many reflex pathways, including those mediating presynaptic inhibition.

  6. Neuronal intrinsic properties shape naturally-evoked sensory inputs in the dorsal horn of the spinal cord

    Directory of Open Access Journals (Sweden)

    Cecilia eReali

    2013-12-01

    Full Text Available Intrinsic electrophysiological properties arising from specific combinations of voltage-gated channels are fundamental for the performance of small neural networks in invertebrates, but their role in large-scale vertebrate circuits remains controversial. Although spinal neurons have complex intrinsic properties, some tasks produce high-conductance states that override intrinsic conductances, minimizing their contribution to network function. Because the detection and coding of somato-sensory information at early stages probably involves a relatively small number of neurons, we speculated that intrinsic electrophysiological properties are likely involved in the processing of sensory inputs by dorsal horn neurons (DHN. To test this idea, we took advantage of an integrated spinal cord–hindlimbs preparation from turtles allowing the combination of patch-clamp recordings of DHN embedded in an intact network, with accurate control of the extracellular milieu. We found that plateau potentials and low threshold spikes (LTS -mediated by L- and T-type Ca2+ channels, respectively- generated complex dynamics by interacting with naturally evoked synaptic potentials. Inhibitory receptive fields could be changed in sign by activation of the LTS. On the other hand, the plateau potential transformed sensory signals in the time domain by generating persistent activity triggered on and off by brief sensory inputs and windup of the response to repetitive sensory stimulation. Our findings suggest that intrinsic properties dynamically shape sensory inputs and thus represent a major building block for sensory processing by DHN. Intrinsic conductances in DHN appear to provide a mechanism for plastic phenomena such as dynamic receptive fields and sensitization to pain.

  7. Suppression of KCNQ/M (Kv7) potassium channels in the spinal cord contributes to the sensitization of dorsal horn WDR neurons and pain hypersensitivity in a rat model of bone cancer pain.

    Science.gov (United States)

    Cai, Jie; Fang, Dong; Liu, Xiao-Dan; Li, Song; Ren, Juan; Xing, Guo-Gang

    2015-03-01

    Primary and metastatic cancers that affect bones are frequently associated with severe and intractable pain. The mechanisms underlying the development of bone cancer pain are largely unknown. In the present study, we investigated whether inhibition of KCNQ/M (Kv7) potassium channels in the spinal cord contributes to the development of bone cancer pain via sensitization of dorsal horn wide dynamic range (WDR) neurons. Using a rat model of bone cancer pain based on intratibial injection of MRMT-1 tumor cells, we observed a significant increase in C-fiber responses of dorsal horn WDR neurons in the MRMT-1 injected rats, indicating sensitization of spinal WDR neurons in bone cancer rats. Furthermore, we discovered that blockade of KCNQ/M channels in the spinal cord by local administration of XE-991, a specific KCNQ/M channel blocker, caused a robust increase in excitability of dorsal horn WDR neurons, while, producing obvious pain hypersensitivity in normal rats. On the contrary, activation of spinal KCNQ/M channels by retigabine, a selective KCNQ/M channel opener, not only inhibited the bone cancer‑induced hyperexcitability of dorsal horn WDR neurons, but also alleviated mechanical allodynia and thermal hyperalgesia in the bone cancer rats, while all of these effects of retigabine could be blocked by KCNQ/M-channel antagonist XE-991. All things considered, these results suggest that suppression of KCNQ/M channels in the spinal cord likely contributes to the development of bone cancer pain via sensitization of dorsal horn WDR neurons in rats following tumor cell inoculation.

  8. Endomorphins: localization, release and action on rat dorsal horn neurons.

    Science.gov (United States)

    Dun, N J; Dun, S L; Wu, S Y; Williams, C A; Kwok, E H

    2000-01-01

    Endomorphin (Endo) 1 and 2, two tetrapeptides isolated from the bovine and human brain, have been proposed to be the endogenous ligand for the mu-opiate receptor. A multi-disciplinary study was undertaken to address the issues of localization, release and biological action of Endo with respect to the rat dorsal horn. First, immunohistochemical studies showed that Endo-1- or Endo-2-like immunoreactivity (Endo-1- or Endo-2-LI) is selectively expressed in fiber-like elements occupying the superficial layers of the rat dorsal horn, which also exhibit a high level of mu-opiate receptor immunoreactivity. Second, release of immunoreactive Endo-2-like substances (irEndo) from the in vitro rat spinal cords upon electrical stimulation of dorsal root afferent fibers was detected by the immobilized antibody microprobe technique. The site of release corresponded to laminae I and II where the highest density of Endo-2-LI fibers was localized. Lastly, whole-cell patch clamp recordings from substantia gelatinosa (SG) neurons of rat lumbar spinal cord slices revealed two distinct actions of exogenous Endo-1 and Endo-2: (1) depression of excitatory and/or inhibitory postsynaptic potentials evoked by stimulation of dorsal root entry zone, and (2) hyperpolarization of SG neurons. These two effects were prevented by the selective mu-opiate receptor antagonist beta-funaltrexamine. The localization of endomorphin-positive fibers in superficial layers of the dorsal horn and the release of irEndo upon stimulation of dorsal root afferents together with the observation that Endo inhibits the activity of SG neurons by interacting with mu-opiate receptors provide additional support of a role of Endo as the endogenous ligand for the mu-opiate receptor in the rat dorsal horn.

  9. Modeling zero-lag synchronization of dorsal horn neurons during the traveling of electrical waves in the cat spinal cord

    OpenAIRE

    2013-01-01

    The first electrophysiological evidence of the phenomenon of traveling electrical waves produced by populations of interneurons within the spinal cord was reported by our interdisciplinary research group. Two interesting observations derive from this study: first, the negative spontaneous cord dorsum potentials (CDPs) that are superimposed on the propagating sinusoidal electrical waves are not correlated with any scratching phase; second, these CDPs do not propagate along the lumbosacral spin...

  10. Modeling zero-lag synchronization of dorsal horn neurons during the traveling of electrical waves in the cat spinal cord.

    Science.gov (United States)

    Kato, Hideyuki; Cuellar, Carlos A; Delgado-Lezama, Rodolfo; Rudomin, Pablo; Jimenez-Estrada, Ismael; Manjarrez, Elias; Mirasso, Claudio R

    2013-07-01

    The first electrophysiological evidence of the phenomenon of traveling electrical waves produced by populations of interneurons within the spinal cord was reported by our interdisciplinary research group. Two interesting observations derive from this study: first, the negative spontaneous cord dorsum potentials (CDPs) that are superimposed on the propagating sinusoidal electrical waves are not correlated with any scratching phase; second, these CDPs do not propagate along the lumbosacral spinal segments, but they appear almost simultaneously at different spinal segments. The aim of this study was to provide experimental data and a mathematical model to explain the simultaneous occurrence of traveling waves and the zero-lag synchronization of some CDPs.

  11. Modeling zero-lag synchronization of dorsal horn neurons during the traveling of electrical waves in the cat spinal cord

    Science.gov (United States)

    Kato, Hideyuki; Cuellar, Carlos A; Delgado-Lezama, Rodolfo; Rudomin, Pablo; Jimenez-Estrada, Ismael; Manjarrez, Elias; Mirasso, Claudio R

    2013-01-01

    The first electrophysiological evidence of the phenomenon of traveling electrical waves produced by populations of interneurons within the spinal cord was reported by our interdisciplinary research group. Two interesting observations derive from this study: first, the negative spontaneous cord dorsum potentials (CDPs) that are superimposed on the propagating sinusoidal electrical waves are not correlated with any scratching phase; second, these CDPs do not propagate along the lumbosacral spinal segments, but they appear almost simultaneously at different spinal segments. The aim of this study was to provide experimental data and a mathematical model to explain the simultaneous occurrence of traveling waves and the zero-lag synchronization of some CDPs. PMID:24303110

  12. Direct excitation of deep dorsal horn neurones in the rat spinal cord by the activation of postsynaptic P2X receptors.

    Science.gov (United States)

    Shiokawa, Hiroaki; Nakatsuka, Terumasa; Furue, Hidemasa; Tsuda, Makoto; Katafuchi, Toshihiko; Inoue, Kazuhide; Yoshimura, Megumu

    2006-06-15

    ATP mediates somatosensory transmission in the spinal cord through the activation of P2X receptors. Nonetheless, the functional significance of postsynaptic P2X receptors in spinal deep dorsal horn neurones is still not yet well understood. Using the whole-cell patch-clamp technique, we investigated whether the activation of postsynaptic P2X receptors can modulate the synaptic transmission in lamina V neurones of postnatal day (P) 9-12 spinal cord slices. At a holding potential of -70 mV, ATPgammaS (100 microm), a nonhydrolysable ATP analogue, generated an inward current, which was resistant to tetrodotoxin (1 microm) in 61% of the lamina V neurones. The ATPgammaS-induced inward current was accompanied by a significant increase in the frequency of glutamatergic miniature excitatory postsynaptic currents (mEPSCs) in the majority of lamina V neurones. The ATPgammaS-induced inward current was not reproduced by P2Y receptor agonists, UTP (100 microm), UDP (100 microm), and 2-methylthio ADP (100 microm), and it was also not affected by the addition of guanosine-5'-O-(2-thiodiphosphate) (GDPbetaS) into the pipette solution, thus suggesting that ionotropic P2X receptors were activated by ATPgammaS instead of metabotropic P2Y receptors. On the other hand, alpha,beta-methylene ATP (100 microm) did not change any membrane current, but instead increased the mEPSC frequency in the majority of lamina V neurones. The ATPgammaS-induced inward current was suppressed by pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) (10 microm), but not by trinitrophenyl-ATP (TNP-ATP) (1 microm). Furthermore, we found that ATPgammaS (100 microm) produced a clear inward current which was observed in all lamina V neurones over P16 spinal cord slices, in contrast to P9-12. These results indicate that distinct subtypes of P2X receptors were functionally expressed at the post- and presynaptic sites in lamina V neurones, both of which may contribute to the hyperexcitability of lamina V in

  13. 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

    horn, was distinguished by the ability to generate a burst response following a hyperpolarization from rest or during a depolarization from a hyperpolarized holding potential. The burst response was inactivated at the resting membrane potential. 3. The burst response was mediated by a low threshold Ca2......+ spike assumed to be mediated by T-type Ca2+ channels since it resisted tetrodotoxin and was blocked by 3 mM Co2+ or 100-300 microM Ni2+ and resembled the low threshold spike (LTS) described elsewhere. 4. Some burst-generating cells also displayed plateau potentials mediated by L-type Ca2+ channels....... In these cells the burst following a hyperpolarizing current pulse, applied from the resting membrane potential, facilitated the activation of the plateau potential. Wind-up of the plateau potential was produced when the hyperpolarizing pulse generating the burst was repeated at 0.1-0.3 Hz or faster. 5...

  14. Visualizing sensory transmission between dorsal root ganglion and dorsal horn neurons in co-culture with calcium imaging.

    Science.gov (United States)

    Ohshiro, Hiroyuki; Ogawa, Shinji; Shinjo, Katsuhiro

    2007-09-15

    Sensory information is conveyed to the central nervous system by primary afferent neurons within dorsal root ganglia (DRG), which synapse onto neurons of the dorsal horn of the spinal cord. This synaptic connection is central to the processing of both sensory and pain stimuli. Here, we describe a model system to monitor synaptic transmission between DRG neurons and dorsal horn neurons that is compatible with high-throughput screening. This co-culture preparation comprises DRG and dorsal horn neurons and utilizes Ca(2+) imaging with the indicator dye Fura-2 to visualize synaptic transmission. Addition of capsaicin to co-cultures stimulated DRG neurons and led to activation of dorsal horn neurons as well as increased intracellular Ca(2+) concentrations. This effect was dose-dependent and absent when DRG neurons were omitted from the culture. NMDA receptors are a critical component of synapses between DRG and dorsal horn neurons as MK-801, a use-dependent non-competitive antagonist, prevented activation of dorsal horn neurons following capsaicin treatment. This model system allows for rapid and efficient analysis of noxious stimulus-evoked Ca(2+) signal transmission and provides a new approach both for investigating synaptic transmission in the spinal cord and for screening potential analgesic compounds.

  15. Fos, nociception and the dorsal horn.

    Science.gov (United States)

    Coggeshall, Richard E

    2005-12-01

    The protooncogene c-fos is rapidly activated after noxious stimuli to express the protein Fos in spinal dorsal horn neurons that are in the 'correct' locations for nociceptive information transfer. As such, therefore, mapping Fos expression in these neurons is at present the best global marker for efficiently locating populations of neurons in the awake animal that respond to nociceptive input. This allows, among other things, precise behavioral measurements to be correlated with Fos expression. Two arenas where mapping dorsal horn Fos expression has made a major impact are in the anatomy of nociceptive systems and as a useful assay for the analgesic properties of various therapeutic regimens. Also Fos expression is the only way to map populations of neurons that are responding to non-localized input such as withdrawal after addiction and vascular occlusion. Another insight is that it shows a clear activation of neurons in superficial 'pain-processing' laminae by innocuous stimuli after nerve lesions, a finding that presumably bears on the allodynia that often accompanies these lesions. It is to be understood, however, that the Fos localizations are not sufficient unto themselves, but the major function of these studies is to efficiently locate populations of cells in nociceptive pathways so that powerful anatomic and physiologic techniques can be brought to bear efficiently. Thus, the purpose of this review is to summarize the studies whose numbers are geometrically expanding that deal with Fos in the dorsal horn and the conclusions therefrom.

  16. Laminar distribution of GABAA- and glycine-receptor mediated tonic inhibition in the dorsal horn of the rat lumbar spinal cord: effects of picrotoxin and strychnine on expression of Fos-like immunoreactivity.

    Science.gov (United States)

    Cronin, John N; Bradbury, Elizabeth J; Lidierth, Malcolm

    2004-11-01

    Inhibitory mechanisms are essential in suppressing the development of allodynia and hyperalgesia in the normal animal and there is evidence that loss of inhibition can lead to the development of neuropathic pain. We used Fos expression to map the distribution of tonically inhibited cells in the healthy rat lumbar spinal cord. In a control group, Fos-like immunoreactive (Fos-LI) cells were rare, averaging 7.5+/-2.2 cells (mean+/-SEM; N=13 sections) per 20 microm thick section of dorsal horn. This rose to 103+/-11 (mean+/-SEM; N=20) in picrotoxin-treated rats and to 88+/-11 (mean+/-SEM; N=18) in strychnine-treated rats. These changes were significant (ANOVA; Pstrychnine-treated animals. Picrotoxin induced a significant increase in the number of Fos-LI cells throughout the dorsal horn (lamina I-VI) while strychnine significantly elevated Fos-like immunoreactivity only in deep laminae (III-VI). For both picrotoxin and strychnine, the increase in Fos-like immunoreactivity peaked in lamina V (at 3579+/-319 and 3649+/-375% of control, respectively; mean+/-SEM) but for picrotoxin an additional peak was observed in the outer part of lamina II (1959+/-196%). Intrathecal administration of both GABAA and glycine receptor antagonists has been shown elsewhere to induce tactile allodynia. The present data suggest that this allodynia could arise due to blockade of tonic GABAA and glycine-receptor mediated inhibition in the deep dorsal horn. GABAA antagonists also induce hypersensitivity to noxious inputs. The blockade of tonic inhibition in the superficial dorsal horn shown here may underlie this hyperalgesia.

  17. 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.

  18. Dorsal horn-enriched genes identified by DNA microarray, in situ hybridization and immunohistochemistry

    Directory of Open Access Journals (Sweden)

    Koblan Kenneth S

    2002-08-01

    Full Text Available Abstract Background Neurons in the dorsal spinal cord play important roles in nociception and pain. These neurons receive input from peripheral sensory neurons and then transmit the signals to the brain, as well as receive and integrate descending control signals from the brain. Many molecules important for pain transmission have been demonstrated to be localized to the dorsal horn of the spinal cord. Further understanding of the molecular interactions and signaling pathways in the dorsal horn neurons will require a better knowledge of the molecular neuroanatomy in the dorsal spinal cord. Results A large scale screening was conducted for genes with enriched expression in the dorsal spinal cord using DNA microarray and quantitative real-time PCR. In addition to genes known to be specifically expressed in the dorsal spinal cord, other neuropeptides, receptors, ion channels, and signaling molecules were also found enriched in the dorsal spinal cord. In situ hybridization and immunohistochemistry revealed the cellular expression of a subset of these genes. The regulation of a subset of the genes was also studied in the spinal nerve ligation (SNL neuropathic pain model. In general, we found that the genes that are enriched in the dorsal spinal cord were not among those found to be up-regulated in the spinal nerve ligation model of neuropathic pain. This study also provides a level of validation of the use of DNA microarrays in conjunction with our novel analysis algorithm (SAFER for the identification of differences in gene expression. Conclusion This study identified molecules that are enriched in the dorsal horn of the spinal cord and provided a molecular neuroanatomy in the spinal cord, which will aid in the understanding of the molecular mechanisms important in nociception and pain.

  19. Stability of long term facilitation and expression of zif268 and Arc in the spinal cord dorsal horn is modulated by conditioning stimulation within the physiological frequency range of primary afferent fibers.

    Science.gov (United States)

    Haugan, F; Wibrand, K; Fiskå, A; Bramham, C R; Tjølsen, A

    2008-07-17

    Long term facilitation (LTF) of C-fiber-evoked firing of wide dynamic range neurons in the spinal dorsal horn in response to conditioning stimulation (CS) of afferent fibers is a widely studied cellular model of spinal nociceptive sensitization. Although 100 Hz CS of primary afferent fibers is commonly used to induce spinal cord LTF, this frequency exceeds the physiological firing range. Here, we examined the effects of electrical stimulation of the sciatic nerve within the physiological frequency range on the magnitude and stability of the C-fiber-evoked responses of wide dynamic range neurons and the expression of immediate early genes (c-fos, zif268, and Arc) in anesthetized rats. Stimulation frequencies of 3, 30 and 100 Hz all induced facilitation of similar magnitude as recorded at 1 h post-CS. Strikingly, however, 3 Hz-induced potentiation of the C-fiber responses was decremental, whereas both 30 and 100 Hz stimulation resulted in stable, non-decremental facilitation over 3 h of recording. The number of dorsal horn neurons expressing c-fos, but not zif268 or Arc, was significantly elevated after 3 Hz CS and increased proportionally with stimulation rate. In contrast, a stable LTF of C-fiber responses was obtained at 30 and 100 Hz CS, and at these frequencies there was a sharp increase in zif268 expression and appearance of Arc-positive neurons. The results show that response facilitation can be induced by stimulation frequencies in the physiological range (3 and 30 Hz). Three hertz stimulation induced the early phase of LTF, but the responses were decremental. Arc and zif268, two genes previously coupled to LTP of synaptic transmission in the adult brain, are upregulated at the same frequencies that give stable LTF (30 and 100 Hz). This frequency-dependence is important for understanding how the afferent firing pattern affects neuronal plasticity and nociception in the spinal dorsal horn.

  20. Capillary electrophoresis combined with microdialysis in the human spinal cord: a new tool for monitoring rapid peroperative changes in amino acid neurotransmitters within the dorsal horn.

    Science.gov (United States)

    Parrot, Sandrine; Sauvinet, Valérie; Xavier, Jean-Michel; Chavagnac, Delphine; Mouly-Badina, Laurence; Garcia-Larrea, Luis; Mertens, Patrick; Renaud, Bernard

    2004-06-01

    A method originally developed for the separation of the three neurotransmitters gamma-aminobutyric acid (GABA), glutamate (Glu) and L-aspartate (L-Asp) in microdialysis samples from rat brain (Sauvinet et al., Electrophoresis 2003, 24, 3187-3196) was applied to human spinal dialysates obtained during peroperative microdialysis from patients undergoing surgery against chronic pain. Molecules were tagged on their primary amine function with the fluorogene agent, naphthalene-2,3-dicarboxaldehyde (NDA), and, after separation by capillary electrophoresis (CE, 75 mmol/L borate buffer, pH 9.2, containing 70 mmol/L sodium dodecyl sulfate and 10 mmol/L hydroxypropyl-beta-cyclodextrin, + 25 kV voltage), were detected by laser-induced fluorescence detection (LIFD) using a 442 nm helium-cadmium laser. The complete method, including microdialysis sampling and analysis by CE-LIFD, has been validated for the analysis of human spinal microdialysates. The analytical detection limits were 1, 3.7 and 17 nmol/L for GABA, Glu and L-Asp respectively. This method allows an accurate measurement of the three amino acid neurotransmitters during an in vivo monitoring performed as rapidly as every minute in the human spinal dorsal horn. In addition, the effect of a brief peroperative electrical stimulation of the dorsal rootlets was investigated. The results obtained illustrate the advantages of combining microdialysis with CE-LIFD for studying neurotransmitters with such a high sampling rate.

  1. AMPA receptor trafficking in inflammation-induced dorsal horn central sensitization

    Institute of Scientific and Technical Information of China (English)

    Yuan-Xiang Tao

    2012-01-01

    Activity-dependent postsynaptic receptor trafficking is critical for long-term synaptic plasticity in the brain,but it is unclear whether this mechanism actually mediates the spinal cord dorsal horn central sensitization (a specific form of synaptic plasticity) that is associated with persistent pain.Recent studies have shown that peripheral inflammation drives changes in α-amino-3-hydroxy-5-methy1-4-isoxazolepropionic acid receptor (AMPAR) subunit trafficking in the dorsal horn and that such changes contribute to the hypersensitivity that underlies persistent pain.Here,we review current evidence to illustrate how spinal cord AMPARs participate in the dorsal horn central sensitization associated with persistent pain.Understanding these mechanisms may allow the development of novel therapeutic strategies for treating persistent pain.

  2. Single-unit analysis of the spinal dorsal horn in patients with neuropathic pain.

    Science.gov (United States)

    Guenot, Marc; Bullier, Jean; Rospars, Jean-Pierre; Lansky, Petr; Mertens, Patrick; Sindou, Marc

    2003-04-01

    Despite the key role played by the dorsal horn of the spinal cord in pain modulation, single-unit recordings have only been performed very rarely in this structure in humans. The authors report the results of a statistical analysis of 64 unit recordings from the human dorsal horn. The recordings were done in three groups of patients: patients with deafferentation pain resulting from brachial plexus avulsion, patients with neuropathic pain resulting from peripheral nerve injury, and patients with pain resulting from disabling spasticity. The patterns of neuronal activities were compared among these three groups. Nineteen neurons were recorded in the dorsal horns of five patients undergoing DREZotomy for a persistent pain syndrome resulting from peripheral nerve injury (i.e., nondeafferented dorsal horns), 31 dorsal horn neurons were recorded in nine patients undergoing DREZotomy for a persistent pain syndrome resulting from brachial plexus avulsion (i.e., deafferented dorsal horns), and 14 neurons were recorded in eight patients undergoing DREZotomy for disabling spasticity. These groups were compared in terms of mean frequency, coefficient of variation of the discharge, other properties of the neuronal discharge studied by the nonparametric test of Wald-Wolfowitz, and the possible presence of bursts. The coefficient of variation tended to be higher in the deafferented dorsal horn group than in the other two groups. Two neurons displaying burst activity could be recorded, both of which belonged to the deafferented dorsal horn group. A significant difference was found in term of neuronal behavior between the peripheral nerve trauma group and the other groups: The brachial plexus avulsion and disabling spasticity groups were very similar, including various types of neuronal behavior, whereas the peripheral nerve lesion group included mostly neurons with "nonrandom" patterns of discharge (i.e., with serial dependency of interspike intervals).

  3. Loss of inhibitory tone on spinal cord dorsal horn spontaneously and nonspontaneously active neurons in a mouse model of neuropathic pain.

    Science.gov (United States)

    Medrano, Maria Carmen; Dhanasobhon, Dhanasak; Yalcin, Ipek; Schlichter, Rémy; Cordero-Erausquin, Matilde

    2016-07-01

    Plasticity of inhibitory transmission in the spinal dorsal horn (SDH) is believed to be a key mechanism responsible for pain hypersensitivity in neuropathic pain syndromes. We evaluated this plasticity by recording responses to mechanical stimuli in silent neurons (nonspontaneously active [NSA]) and neurons showing ongoing activity (spontaneously active [SA]) in the SDH of control and nerve-injured mice (cuff model). The SA and NSA neurons represented 59% and 41% of recorded neurons, respectively, and were predominantly wide dynamic range (WDR) in naive mice. Nerve-injured mice displayed a marked decrease in the mechanical threshold of the injured paw. After nerve injury, the proportion of SA neurons was increased to 78%, which suggests that some NSA neurons became SA. In addition, the response to touch (but not pinch) was dramatically increased in SA neurons, and high-threshold (nociceptive specific) neurons were no longer observed. Pharmacological blockade of spinal inhibition with a mixture of GABAA and glycine receptor antagonists significantly increased responses to innocuous mechanical stimuli in SA and NSA neurons from sham animals, but had no effect in sciatic nerve-injured animals, revealing a dramatic loss of spinal inhibitory tone in this situation. Moreover, in nerve-injured mice, local spinal administration of acetazolamide, a carbonic anhydrase inhibitor, restored responses to touch similar to those observed in naive or sham mice. These results suggest that a shift in the reversal potential for anions is an important component of the abnormal mechanical responses and of the loss of inhibitory tone recorded in a model of nerve injury-induced neuropathic pain.

  4. Short-term plasticity in turtle dorsal horn neurons mediated by L-type Ca2+ channels

    DEFF Research Database (Denmark)

    Russo, R E; Hounsgaard, J

    1994-01-01

    Windup--the gradual increase of the response--of dorsal horn neurons to repeated activation of primary afferents is an elementary form of short-term plasticity that may mediate central sensitization to pain. In deep dorsal horn neurons of the turtle spinal cord in vitro we report windup...... for intrinsic postsynaptic properties in nociceptive plasticity and for L-type Ca2+ channels as a promising target for therapeutic intervention....

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Dorsal Horn Parvalbumin Neurons Are Gate-Keepers of Touch-Evoked Pain after Nerve Injury

    Directory of Open Access Journals (Sweden)

    Hugues Petitjean

    2015-11-01

    Full Text Available Neuropathic pain is a chronic debilitating disease that results from nerve damage, persists long after the injury has subsided, and is characterized by spontaneous pain and mechanical hypersensitivity. Although loss of inhibitory tone in the dorsal horn of the spinal cord is a major contributor to neuropathic pain, the molecular and cellular mechanisms underlying this disinhibition are unclear. Here, we combined pharmacogenetic activation and selective ablation approaches in mice to define the contribution of spinal cord parvalbumin (PV-expressing inhibitory interneurons in naive and neuropathic pain conditions. Ablating PV neurons in naive mice produce neuropathic pain-like mechanical allodynia via disinhibition of PKCγ excitatory interneurons. Conversely, activating PV neurons in nerve-injured mice alleviates mechanical hypersensitivity. These findings indicate that PV interneurons are modality-specific filters that gate mechanical but not thermal inputs to the dorsal horn and that increasing PV interneuron activity can ameliorate the mechanical hypersensitivity that develops following nerve injury.

  7. Peripheral nerve injury sensitizes neonatal dorsal horn neurons to tumor necrosis factor-α

    OpenAIRE

    2009-01-01

    Abstract Background Little is known about whether peripheral nerve injury during the early postnatal period modulates synaptic efficacy in the immature superficial dorsal horn (SDH) of the spinal cord, or whether the neonatal SDH network is sensitive to the proinflammatory cytokine TNFα under neuropathic conditions. Thus we examined the effects of TNFα on synaptic transmission and intrinsic membrane excitability in developing rat SDH neurons in the absence or presence of sciatic nerve damage....

  8. 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...... 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...

  9. 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.

  10. Acupuncture inhibition on neuronal activity of spinal dorsal horn induced by noxious colorectal distention in rat

    Institute of Scientific and Technical Information of China (English)

    Pei-Jing Rong; Bing Zhu; Qi-Fu Huang; Xin-Yan Gao; Hui Ben; Yan-Hua Li

    2005-01-01

    AIM: To observe how acupuncture stimulation influences the visceral nociception in rat and to clarify the interactions between acupuncture or somatic input and visceral nociceptive inputs in the spinal dorsal horn. These will provide scientific base for illustrating the mechanism of acupuncture on visceral pain.METHODS: Experiments were performed on SpragueDawley rats and the visceral nociceptive stimulus was generated by colorectal distention (CRD). Unit discharges from individual single neuron were recorded extracellularly with glass-microelectrode in L1-3 spinal dorsal horn.Acupuncture stimulation was applied at contralateral heterotopic acupoint and ipsilateral homotopic acupoint,both of which were innervated by the same segments that innervate also the colorectal-gut.RESULTS: The visceral nociception could be inhibited at the spinal level by the heterotopic somatic mechanical stimulation and acupuncture. The maximal inhibition was induced by acupuncture or the somatic noxious stimulation at spinal dorsal horn level with inhibiting rate of 68.61%and 60.79%, respectively (P<0.01 and <0.001). In reversible spinalized rats (cervical-thoracic cold block)both spontaneous activity and responses to CRD increased significantly in 16/20 units examined, indicating the existence of tonic descending inhibition. The inhibition of acupuncture on the noxious CRD disappeared totally in the reversible spinalized rats (P<0.001).CONCLUSION: The inputs of noxious CRD and acupuncture may interact at the spinal level. The nociceptive visceral inputs could be inhibited by acupuncture applied to hetero-topic acupoint. The effect indicates that the spinal dorsal horn plays a significant role in mediating the inhibition of acupuncture and somatic stimulation on the neuronal response to the noxious visceral stimulation and the inhibition is modulated by upper cervical cord and/or supra-spinal center.

  11. Pain-related synaptic plasticity in spinal dorsal horn neurons: role of CGRP

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    Willis William D

    2006-09-01

    Full Text Available Abstract Background The synaptic and cellular mechanisms of pain-related central sensitization in the spinal cord are not fully understood yet. Calcitonin gene-related peptide (CGRP has been identified as an important molecule in spinal nociceptive processing and ensuing behavioral responses, but its contribution to synaptic plasticity, cellular mechanisms and site of action in the spinal cord remain to be determined. Here we address the role of CGRP in synaptic plasticity in the spinal dorsal horn in a model of arthritic pain. Results Whole-cell current- and voltage-clamp recordings were made from substantia gelatinosa (SG neurons in spinal cord slices from control rats and arthritic rats (> 6 h postinjection of kaolin/carrageenan into the knee. Monosynaptic excitatory postsynaptic currents (EPSCs were evoked by electrical stimulation of afferents in the dorsal root near the dorsal root entry zone. Neurons in slices from arthritic rats showed increased synaptic transmission and excitability compared to controls. A selective CGRP1 receptor antagonist (CGRP8-37 reversed synaptic plasticity in neurons from arthritic rats but had no significant effect on normal transmission. CGRP facilitated synaptic transmission in the arthritis pain model more strongly than under normal conditions where both facilitatory and inhibitory effects were observed. CGRP also increased neuronal excitability. Miniature EPSC analysis suggested a post- rather than pre-synaptic mechanism of CGRP action. Conclusion This study is the first to show synaptic plasticity in the spinal dorsal horn in a model of arthritic pain that involves a postsynaptic action of CGRP on SG neurons.

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

    Science.gov (United States)

    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.

  13. 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.

  14. Phorbol Ester Modulation of Ca2+ Channels Mediates Nociceptive Transmission in Dorsal Horn Neurones

    Directory of Open Access Journals (Sweden)

    Gary J. Stephens

    2013-05-01

    Full Text Available Phorbol esters are analogues of diacylglycerol which activate C1 domain proteins, such as protein kinase C (PKC. Phorbol ester/PKC pathways have been proposed as potential therapeutic targets for chronic pain states, potentially by phosphorylating proteins involved in nociception, such as voltage-dependent Ca2+ channels (VDCCs. In this brief report, we investigate the potential involvement of CaV2 VDCC subtypes in functional effects of the phorbol ester, phorbol 12-myristate 13-acetate (PMA on nociceptive transmission in the spinal cord. Effects of PMA and of selective pharmacological blockers of CaV2 VDCC subtypes on nociceptive transmission at laminae II dorsal horn neurones were examined in mouse spinal cord slices. Experiments were extended to CaV2.3(−/− mice to complement pharmacological studies. PMA increased the mean frequency of spontaneous postsynaptic currents (sPSCs in dorsal horn neurones, without an effect on event amplitude or half-width. sPSC frequency was reduced by selective VDCC blockers, w-agatoxin-IVA (AgTX; CaV2.1, w-conotoxin-GVIA (CTX; CaV2.2 or SNX-482 (CaV2.3. PMA effects were attenuated in the presence of each VDCC blocker and, also, in CaV2.3(−/− mice. These initial data demonstrate that PMA increases nociceptive transmission at dorsal horn neurones via actions on different CaV2 subtypes suggesting potential anti-nociceptive targets in this system.

  15. 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.

  16. Transcriptional control of GABAergic neuron development in the dorsal spinal cord

    Institute of Scientific and Technical Information of China (English)

    Huang Jing; Wu Shengxi

    2008-01-01

    GABAergic neurons are the major inhibitory interneurons that powerfully control the function of spinal neuronalnet works. In recent years, tremendous progresses have been made in understanding the transcriptional control of GABAergic neuron development in the dorsal spinal cord. New experimental approaches provide a relatively high throughput way to study the molecular regulation of subgroup fate determination. Our understanding of the molecular mechanisms on GABAergic neuron development in the dorsal spinal cord is rapidly expanding. Recent studies have defined several transcription factors that play essential roles in GABAergic neuron development in the spinal dorsal horn. Here, we review results of very recent analyses of the mechanisms that specify the GABAergic neuron development in the dorsal spinal cord, especially the progresses in the homeodomain (HD) and basic-helix-loop-helix(bHLH) containing transcription factors.

  17. Dissociation of μ- and δ-opioid inhibition of glutamatergic synaptic transmission in superficial dorsal horn

    Directory of Open Access Journals (Sweden)

    Vaughan Christopher W

    2010-10-01

    Full Text Available Abstract Background There is anatomical and behavioural evidence that μ- and δ-opioid receptors modulate distinct nociceptive modalities within the superficial dorsal horn. The aim of the present study was to examine whether μ- and δ-opioid receptor activation differentially modulates TRP sensitive inputs to neurons within the superficial dorsal horn. To do this, whole cell patch clamp recordings were made from lamina I - II neurons in rat spinal cord slices in vitro to examine the effect of opioids on TRP agonist-enhanced glutamatergic spontaneous miniature excitatory postsynaptic currents (EPSCs. Results Under basal conditions the μ-opioid agonist DAMGO (3 μM reduced the rate of miniature EPSCs in 68% of neurons, while the δ- and κ-opioid agonists deltorphin-II (300 nM and U69593 (300 nM did so in 13 - 17% of neurons tested. The TRP agonists menthol (400 μM and icilin (100 μM both produced a Ca2+-dependent increase in miniature EPSC rate which was unaffected by the voltage dependent calcium channel (VDCC blocker Cd2+. The proportion of neurons in which deltorphin-II reduced the miniature EPSC rate was enhanced in the presence of icilin (83%, but not menthol (0%. By contrast, the proportion of DAMGO and U69593 responders was unaltered in the presence of menthol (57%, 0%, or icilin (57%, 17%. Conclusions These findings demonstrate that δ-opioid receptor activation selectively inhibits inputs activated by icilin, whereas μ-opioid receptor activation has a more widespread effect on synaptic inputs to neurons in the superficial dorsal horn. These findings suggest that δ-opioids may provide a novel analgesic approach for specific, TRPA1-like mediated pain modalities.

  18. Altered intrinsic and synaptic properties of lumbosacral dorsal horn neurons in a mouse model of colitis.

    Science.gov (United States)

    Farrell, Kristen E; Keely, Simon; Walker, Marjorie M; Brichta, Alan M; Graham, Brett A; Callister, Robert J

    2017-08-23

    Visceral pain in inflammatory and functional gastrointestinal conditions is a major clinical problem. The exact mechanisms underlying the development of pain, during and after visceral inflammation, are unknown clinical and pre-clinical evidence that suggests plasticity within the spinal cord dorsal horn is a contributing factor. Here we use an in vivo preparation and patch-clamp electrophysiology to test whether the synaptic and intrinsic properties of superficial dorsal horn (SDH) neurons are altered 5days after the induction of mild colitis in adult male mice (i.e. during acute inflammation of the colon). Whole-cell recordings were made from lumbosacral (L6-S1) superficial dorsal horn neurons (SDH), in animals under isoflurane anesthesia. Noxious colorectal distension (CRD) was used to identify SDH neurons with colonic inputs, while stimulation of the hind paw and tail was employed to assess convergent cutaneous input. Following inflammation, a significantly increased proportion of SDH neurons received both colonic and cutaneous inputs, compared to neurons in naïve animals. In addition, the nature and magnitude of responses to CRD and cutaneous stimulation differed in inflamed animals, as was spontaneous excitatory synaptic drive. Conversely, several measures of intrinsic excitability were altered in a manner that would decrease SDH network excitability following colitis. We propose that during inflammation, sensitization of colonic afferents results in increased signaling to the SDH. This is accompanied by plasticity in SDH neurons whereby their intrinsic properties are changed to compensate for altered afferent activity. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Endomorphins suppress nociception-induced c-Fos and Zif/268 expression in the rat spinal dorsal horn.

    Science.gov (United States)

    Tateyama, Shingo; Ikeda, Tetsuya; Kosai, Kazuko; Nakamura, Tadashi; Kasaba, Toshiharu; Takasaki, Mayumi; Nishimori, Toshikazu

    2002-09-06

    We evaluated the potency of endomorphin-1 and -2 as endogenous ligands on c-Fos and Zif/268 expression in the spinal dorsal horn by formalin injection to the rat hind paw. Endomorphin-1, -2, or morphine was administered intrathecally or intracerebroventricularly 5 min before formalin injection (5%, 100 microl). All drugs produced marked reductions of formalin-induced c-Fos and Zif/268 immunoreactivity in laminae I and II, and laminae V and VI in the rat lumbar spinal cord. The reductions of Zif/268 expression by endomorphins were greater than those by morphine, while the reductions of c-Fos expression by endomorphins were smaller than those by morphine. These effects of endomorphins were attenuated by pretreatment with naloxone. These results indicate that endomorphin-1 and -2 act as endogenous ligands of mu-opioid receptor in neurons of the spinal dorsal horn and suppress the processing of nociceptive information in the central nervous system.

  1. Peripheral nerve injury sensitizes neonatal dorsal horn neurons to tumor necrosis factor-α

    Directory of Open Access Journals (Sweden)

    Baccei Mark L

    2009-03-01

    Full Text Available Abstract Background Little is known about whether peripheral nerve injury during the early postnatal period modulates synaptic efficacy in the immature superficial dorsal horn (SDH of the spinal cord, or whether the neonatal SDH network is sensitive to the proinflammatory cytokine TNFα under neuropathic conditions. Thus we examined the effects of TNFα on synaptic transmission and intrinsic membrane excitability in developing rat SDH neurons in the absence or presence of sciatic nerve damage. Results The spared nerve injury (SNI model of peripheral neuropathy at postnatal day (P6 failed to significantly alter miniature excitatory (mEPSCs or inhibitory (mIPSCs postsynaptic currents in SDH neurons at P9-11. However, SNI did alter the sensitivity of excitatory synapses in the immature SDH to TNFα. While TNFα failed to influence mEPSCs or mIPSCs in slices from sham-operated controls, it significantly increased mEPSC frequency and amplitude following SNI without modulating synaptic inhibition onto the same neurons. This was accompanied by a significant decrease in the paired-pulse ratio of evoked EPSCs, suggesting TNFα increases the probability of glutamate release in the SDH under neuropathic conditions. Similarly, while SNI alone did not alter action potential (AP threshold or rheobase in SDH neurons at this age, TNFα significantly decreased AP threshold and rheobase in the SNI group but not in sham-operated littermates. However, unlike the adult, the expression of TNFα in the immature dorsal horn was not significantly elevated during the first week following the SNI. Conclusion Developing SDH neurons become susceptible to regulation by TNFα following peripheral nerve injury in the neonate. This may include both a greater efficacy of glutamatergic synapses as well as an increase in the intrinsic excitability of immature dorsal horn neurons. However, neonatal sciatic nerve damage alone did not significantly modulate synaptic transmission or

  2. Antinociception induced by intravenous dipyrone (metamizol) upon dorsal horn neurons: involvement of endogenous opioids at the periaqueductal gray matter, the nucleus raphe magnus, and the spinal cord in rats.

    Science.gov (United States)

    Vazquez, Enrique; Hernandez, Norma; Escobar, William; Vanegas, Horacio

    2005-06-28

    Microinjection of dipyrone (metamizol) into the periaqueductal gray matter (PAG) in rats causes antinociception. This is mediated by endogenous opioidergic circuits located in the PAG itself, in the nucleus raphe magnus and adjacent structures, and in the spinal cord. The clinical relevance of these findings, however, is unclear. Therefore, in the present study, dipyrone was administered intravenously, and the involvement of endogenous opioidergic circuits in the so-induced antinociception was investigated. In rats, responses of dorsal spinal wide-dynamic range neurons to mechanical noxious stimulation of a hindpaw were strongly inhibited by intravenous dipyrone (200 mg/kg). This effect was abolished by microinjection of naloxone (0.5 microg/0.5 microl) into the ventrolateral and lateral PAG or into the nucleus raphe magnus or by direct application of naloxone (50 microg/50 microl) onto the spinal cord surface above the recorded neuron. These results show that dipyrone, a non-opioid analgesic with widespread use in Europe and Latin America, when administered in a clinically relevant fashion causes antinociception by activating endogenous opioidergic circuits along the descending pain control system.

  3. Electrical maturation of spinal neurons in the human fetus: comparison of ventral and dorsal horn.

    Science.gov (United States)

    Tadros, M A; Lim, R; Hughes, D I; Brichta, A M; Callister, R J

    2015-11-01

    The spinal cord is critical for modifying and relaying sensory information to, and motor commands from, higher centers in the central nervous system to initiate and maintain contextually relevant locomotor responses. Our understanding of how spinal sensorimotor circuits are established during in utero development is based largely on studies in rodents. In contrast, there is little functional data on the development of sensory and motor systems in humans. Here, we use patch-clamp electrophysiology to examine the development of neuronal excitability in human fetal spinal cords (10-18 wk gestation; WG). Transverse spinal cord slices (300 μm thick) were prepared, and recordings were made, from visualized neurons in either the ventral (VH) or dorsal horn (DH) at 32°C. Action potentials (APs) could be elicited in VH neurons throughout the period examined, but only after 16 WG in DH neurons. At this age, VH neurons discharged multiple APs, whereas most DH neurons discharged single APs. In addition, at 16-18 WG, VH neurons also displayed larger AP and after-hyperpolarization amplitudes than DH neurons. Between 10 and 18 WG, the intrinsic properties of VH neurons changed markedly, with input resistance decreasing and AP and after-hyperpolarization amplitudes increasing. These findings are consistent with the hypothesis that VH motor circuitry matures more rapidly than the DH circuits that are involved in processing tactile and nociceptive information.

  4. Recombinant neural progenitor transplants in the spinal dorsal horn alleviate chronic central neuropathic pain.

    Science.gov (United States)

    Jergova, Stanislava; Gajavelli, Shyam; Pathak, Nirmal; Sagen, Jacqueline

    2016-04-01

    Neuropathic pain induced by spinal cord injury (SCI) is clinically challenging with inadequate long-term treatment options. Partial pain relief offered by pharmacologic treatment is often counterbalanced by adverse effects after prolonged use in chronic pain patients. Cell-based therapy for neuropathic pain using GABAergic neuronal progenitor cells (NPCs) has the potential to overcome untoward effects of systemic pharmacotherapy while enhancing analgesic potency due to local activation of GABAergic signaling in the spinal cord. However, multifactorial anomalies underlying chronic pain will likely require simultaneous targeting of multiple mechanisms. Here, we explore the analgesic potential of genetically modified rat embryonic GABAergic NPCs releasing a peptidergic NMDA receptor antagonist, Serine-histogranin (SHG), thus targeting both spinal hyperexcitability and reduced inhibitory processes. Recombinant NPCs were designed using either lentiviral or adeno-associated viral vectors (AAV2/8) encoding single and multimeric (6 copies of SHG) cDNA. Intraspinal injection of recombinant cells elicited enhanced analgesic effects compared with nonrecombinant NPCs in SCI-induced pain in rats. Moreover, potent and sustained antinociception was achieved, even after a 5-week postinjury delay, using recombinant multimeric NPCs. Intrathecal injection of SHG antibody attenuated analgesic effects of the recombinant grafts suggesting active participation of SHG in these antinociceptive effects. Immunoblots and immunocytochemical assays indicated ongoing recombinant peptide production and secretion in the grafted host spinal cords. These results support the potential for engineered NPCs grafted into the spinal dorsal horn to alleviate chronic neuropathic pain.

  5. Both Ca2+-permeable and -impermeable AMPA receptors contribute to primary synaptic drive onto rat dorsal horn neurons

    Science.gov (United States)

    Tong, Chi-Kun; MacDermott, Amy B

    2006-01-01

    Blockade of Ca2+-permeable AMPA receptors in the rat spinal cord diminishes the development of hyperalgesia and allodynia associated with peripheral injury. Cobalt uptake studies reveal that Ca2+-permeable AMPA receptors are expressed by some substance P receptor-expressing (NK1R+) neurons in lamina I, as well as other neurons throughout the superficial dorsal horn. Selective elimination of NK1R+ neurons in lamina I and lamina III/IV of the dorsal horn also suppresses development of hyperalgesia and allodynia. These observations raise the possibility that Ca2+-permeable AMPA receptors contribute to excitatory synaptic drive onto the NK1R+ neurons associated with allodynia and hyperalgesia. The first synapse in the pain pathway is the glutamatergic excitatory drive from the primary afferent fibres onto dorsal horn neurons. Therefore, we tested whether Ca2+-permeable AMPA receptors are located on lamina I and lamina III/IV NK1R+ neurons postsynaptic to primary afferent fibres, using inward rectification and polyamine toxins for receptor identification. We examined three different populations of dorsal horn neurons; lamina I NK1R+ neurons, including projection neurons, and non-NK1R+ (NK1R−) neurons including interneurons, and lamina III/IV NK1R+ neurons, believed to contribute to the low-threshold mechanosensory pathway. The majority of synapses in all three groups had rectification indices less than 1.0 and greater than 0.4, indicating that the AMPA receptors at these synapses are a mixture of Ca2+-permeable and -impermeable forms. Lamina III/IV NK1R+ neurons and lamina I NK1R− neurons have a significantly higher proportion of postsynaptic Ca2+-permeable AMPA receptors than lamina I NK1R+ neurons. Thus synaptically positioned Ca2+-permeable AMPA receptors directly contribute to low-threshold sensory afferent drive into the dorsal horn, and can mediate afferent input onto interneurons such as GABAergic neurons. These receptors also contribute to high

  6. Properties of sodium currents in neonatal and young adult mouse superficial dorsal horn neurons.

    Science.gov (United States)

    Tadros, Melissa A; Farrell, Kristen E; Graham, Brett A; Brichta, Alan M; Callister, Robert J

    2015-03-28

    Superficial dorsal horn (SDH) neurons process nociceptive information and their excitability is partly determined by the properties of voltage-gated sodium channels. Recently, we showed the excitability and action potential properties of mouse SDH neurons change markedly during early postnatal development. Here we compare sodium currents generated in neonate (P0-5) and young adult (≥P21) SDH neurons. Whole cell recordings were obtained from lumbar SDH neurons in transverse spinal cord slices (CsF internal, 32°C). Fast activating and inactivating TTX-sensitive inward currents were evoked by depolarization from a holding potential of -100 mV. Poorly clamped currents, based on a deflection in the IV relationship at potentials between -60 and -50 mV, were not accepted for analysis. Current density and decay time increased significantly between the first and third weeks of postnatal development, whereas time to peak was similar at both ages. This was accompanied by more subtle changes in activation range and steady state inactivation. Recovery from inactivation was slower and TTX-sensitivity was reduced in young adult neurons. Our study suggests sodium channel expression changes markedly during early postnatal development in mouse SDH neurons. The methods employed in this study can now be applied to future investigations of spinal cord sodium channel plasticity in murine pain models.

  7. Synaptic organization of substance P, glutamate and GABA-immunoreactive boutons on functionally identified neurons in cat spinal deeper dorsal horn

    Institute of Scientific and Technical Information of China (English)

    魏锋; 赵志奇

    1997-01-01

    In order to determine how nociceptive input conveyed by the C-fibers terminating in superficial lam-inae of the spinal cord reaches the wide dynamic range (WDR) cells in deeper dorsal horn, which functions as ascend-ing projection pathway, the morphological features of some WDR cells in the deeper dorsal horn of the cat lumbar spinal cord were studied by intracellular injection of horseradish peroxidase and physiological characterization. One of the fully stained neurons with somata in lamina V and dendrites that entered lamina Ⅱ were examined by electron mi-croscopy. Immunogold staining of ultrathin sections through the labeled proximal dendrites in lamina Ⅱ revealed that these dendrites received numerous synapses from substance P and glutamate immunoreactive (IR) axons, which were considered originating from C-fibers. In addition, many GABA-IR terminals were found presynaptic to the labeled dendrites. The results, therefore, suggest that the information carried by primary afferent can be sent from t

  8. Effects of the stimulation of colorectal distention on expression of P2X4 and P2X7 receptors in dorsal commissural nucleus and dorsal horn of sacral segment of spinal cord in rats with irritable bowel syndrome%结肠扩张刺激对肠易激综合征大鼠DCN核团及骶髓后角中P2X4及P2X7受体表达的影响

    Institute of Scientific and Technical Information of China (English)

    朱琳; 章鹏宇; 王景杰; 黄裕新

    2011-01-01

    目的 观察肠易激综合征(irritable bowel syndrome,IBS)致内脏高敏感化大鼠在结肠扩张刺激时大鼠腹直肌肌电变化,并观察骶髓后联合核(dorsal commissural nucleus,DCN)和脊髓后角中P2X4和P2X7受体表达的变化情况,为探讨IBS内脏敏化的神经机制提供理论依据.方法 以旋毛虫感染大鼠建立IBS大鼠模型,并以正常大鼠作为对照,实验共分4组:正常大鼠无刺激组,正常大鼠结肠扩张刺激组,IBS大鼠无刺激组,IBS大鼠结肠扩张刺激组.采用免疫组织荧光化学方法,将P2X4和P2X7受体分别标记,观察其在骶髓后角及DCN核团上的表达变化,并同步测定大鼠腹直肌肌电变化.结果 IBS结肠刺激组大鼠腹直肌肌电变化、大鼠骶髓后角及DCN核团中的P2X4和P2X7受体表达较正常大鼠对照组及IBS未刺激组均显著增强.结论 P2X4 和 P2X7受体可能是IBS致内脏敏感性增高的重要因素.%Objective To explore the expression of P2X4 and P2X7 receptors in dorsal commissural nucleus ( DCN ) and dorsal horn of sacral segment of spinal cord in rats with irritable bowel syndrome( IBS ) induced by the stiruulation of colorectal distention,and to provide a theoretical evidence in prevention and treatment of IBS. Methods The rats were gavaged with the Trichinella spiralis to establish the irritable bowel syndrome model,and then divided into 2 groups :IBS without colon distension group and IBS with colon distension group. The normal rats were chosen as controls. and were also divided into 2 groups according to receiving colon distension or not. The expression of P2X4 and P2X7 receptors was detected in neurons of DCN and dorsal horn of the sacral segment of spinal cord in all rats using the immunofluorescent staining method, and the myoelectric changes of the rectus abdominis were recorded at the same time. Result.s The electro-activity of the rectus abdominis and the expression of P2X4 and P2X7 receptors were significantly en

  9. The mechanisms underlying long-term potentiation of C-fiber evoked field potentials in spinal dorsal horn

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-Guo

    2008-01-01

    Long-term potentiation (LTP) of C-fiber evoked feld potentials in spinal dorsal horn is first reported in 1995. Since then, the mechanisms underlying the long-lasting enhancement in synaptic transmission between primary afferent C-fibers and neurons in spinal dorsal horn have been investigated by different laboratories. In this article, the related data were summarized and discussed.

  10. Induction of long-term potentiation in single nociceptive dorsal horn neurons is blocked by the CaMKII inhibitor AIP.

    Science.gov (United States)

    Pedersen, Linda Margareth; Lien, Guro Flor; Bollerud, Ingunn; Gjerstad, Johannes

    2005-04-11

    Neuronal events leading to development of long-term potentiation (LTP) in the nociceptive pathways may be a cellular mechanism underlying central hyperalgesia. Here, we examine whether induction of LTP in nociceptive dorsal horn neurons at depths of 80-500 microm from the cord surface can be affected by spinal application of the Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) inhibitor AIP. Extracellular recordings from single neurons in intact urethane anesthetized Sprague-Dawley rats were performed, and the neuronal A-fiber and C-fiber responses after sciatic nerve test pulses were defined according to latencies. A clear LTP of the nociceptive transmission following sciatic nerve high-frequency stimulation (HFS) was observed in single neurons in laminae I-IV of the dorsal horn. The increase in the C-fiber response after HFS was blocked in the presence of 2.0 mM AIP (P fiber response was not affected by 2.0 mM AIP alone or by vehicle. Thus, our data show that the neuronal process leading to the induction of LTP in the dorsal horn induced by HFS is clearly inhibited by the specific CaMKII inhibitor AIP. It is concluded that CaMKII may be important for the induction of LTP in single nociceptive dorsal horn neurons.

  11. 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.

  12. PROTEIN KINASES AND CENTRAL SENSITIZATION OF SPINAL DORSAL HORN NEURONS:CENTRAL MECHANISMS OF PAIN

    Institute of Scientific and Technical Information of China (English)

    QING LIN

    2003-01-01

    @@ The enhanced responsiveness of spinal dorsal horn neurons, including spinothalamic tract (STT) cells, that follows peripheral tissue injury or inflammation is thought to underlie the development of secondary hyperalgesia and allodynia and is referred to as "central sensitization" because the increases in excitability do not appear to depend on continued activity of peripheral nociceptors.

  13. 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

    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...

  14. Descending serotonergic controls regulate inflammation-induced mechanical sensitivity and methyl-CpG-binding protein 2 phosphorylation in the rat superficial dorsal horn

    Directory of Open Access Journals (Sweden)

    Géranton Sandrine M

    2008-09-01

    Full Text Available Abstract Background Regulation of pain states is, in part, dependent upon plastic changes in neurones within the superficial dorsal horn. There is also compelling evidence that pain states are under the control of descending projections from the brainstem. While a number of transcription factors including Methyl-CpG-binding protein 2 (MeCP2, Zif268 and Fos have been implicated in the regulation of dorsal horn neurone sensitization following injury, modulation of their activity by descending controls has not been investigated. Results Here, we describe how descending controls regulate MeCP2 phosphorylation (P-MeCP2, known to relieve transcriptional repression by MeCP2, and Zif268 and Fos expression in the rat superficial dorsal horn, after CFA injection into the hind paw. First, we report that CFA significantly increased P-MeCP2 in Lamina I and II, from 30 min post injection, with a maximum reached after 1 h. The increase in P-MeCP2 paralleled that of Zif268 and Fos, and P-MeCP2 was expressed in large sub-populations of Zif268 and Fos expressing neurones. Serotonergic depletion of the lumbar spinal cord with 5,7 di-hydroxytryptamine creatinine sulphate (5,7-DHT reduced the inflammation evoked P-MeCP2 in the superficial dorsal horn by 57%, and that of Zif268 and Fos by 37.5% and 30% respectively. Although 5,7-DHT did not change primary thermal hyperalgesia, it significantly attenuated mechanical sensitivity seen in the first 24 h after CFA. Conclusion We conclude that descending serotonergic pathways play a crucial role in regulating gene expression in the dorsal horn and mechanical sensitivity associated with an inflammatory pain state.

  15. Probing glycine receptor stoichiometry in superficial dorsal horn neurones using the spasmodic mouse.

    Science.gov (United States)

    Graham, B A; Tadros, M A; Schofield, P R; Callister, R J

    2011-05-15

    Inhibitory glycine receptors (GlyRs) are pentameric ligand gated ion channels composed of α and β subunits assembled in a 2:3 stoichiometry. The α1/βheteromer is considered the dominant GlyR isoform at 'native' adult synapses in the spinal cord and brainstem. However, the α3 GlyR subunit is concentrated in the superficial dorsal horn (SDH: laminae I-II), a spinal cord region important for processing nociceptive signals from skin, muscle and viscera. Here we use the spasmodic mouse, which has a naturally occurring mutation (A52S) in the α1 subunit of the GlyR, to examine the effect of the mutation on inhibitory synaptic transmission and homeostatic plasticity, and to probe for the presence of various GlyR subunits in the SDH.We usedwhole cell recording (at 22-24◦C) in lumbar spinal cord slices obtained from ketamine-anaesthetized (100 mg kg⁻¹, I.P.) spasmodic and wild-type mice (mean age P27 and P29, respectively, both sexes). The amplitude and decay time constants of GlyR mediated mIPSCs in spasmodic micewere reduced by 25% and 50%, respectively (42.0 ± 3.6 pA vs. 31.0 ± 1.8 pA, P spasmodic GlyRs (EC50 =130 ± 20 μM vs. 64 ± 11 μM, respectively; n =8 and 15, respectively). Differential agonist sensitivity and mIPSC decay times were subsequently used to probe for the presence of α1-containing GlyRs in SDHneurones.Glycine sensitivity, based on the response to 1-3 μM glycine, was reduced in>75% of neurones tested and decay times were faster in the spasmodic sample. Together, our data suggest most GlyRs and glycinergic synapses in the SDH contain α1 subunits and few are composed exclusively of α3 subunits. Therefore, future efforts to design therapies that target the α3 subunit must consider the potential interaction between α1 and α3 subunits in the GlyR.

  16. Rostrocaudal distribution of motoneurones and variation in ventral horn area within a segment of the feline thoracic spinal cord

    DEFF Research Database (Denmark)

    Meehan, Claire Francesca; Ford, Tim W; Road, Jeremy D;

    2004-01-01

    Retrograde transport of horseradish peroxidase, applied to cut peripheral nerves, was used to determine the rostrocaudal distribution of motoneurones supplying different branches of the ventral ramus for a single mid- or caudal thoracic segment in the cat. The motoneurones occupied a length...... of spinal cord equal to the segmental length but displaced rostrally from the segment as defined by the dorsal roots, with the number of motoneurones per unit length of cord higher in the rostral part of a segment (close to the entry of the most rostral dorsal root) than in the caudal part. The cross......-sectional area of the ventral horn showed a rostrocaudal variation that closely paralleled the motoneurone distribution. The ratio between the number of motoneurones per unit length in the caudal and rostral regions of a segment (0.70) was similar to the ratio previously reported for the strength of functional...

  17. 化瘀止痛方外用对骨转移癌疼痛大鼠脊髓背角的影响%Influence of Formula for Resolving Stasis and Relieving Pain on Pinal Cord Dorsal Horn of Rats with Bone Cancer Pain

    Institute of Scientific and Technical Information of China (English)

    邓博; 贾立群; 蔡大勇; 谭煌英; 高福云; 潘琳

    2012-01-01

    目的:研究化瘀止痛方外用对骨转移癌疼痛大鼠的镇痛作用及机制.方法:采用大鼠乳腺癌MRMT-1细胞,按Medhurst方法建立骨转移癌疼痛模型.以唑来膦酸为阳性对照,观察外用药对大鼠脊髓背角神经元原癌基因c - FOS蛋白表达、神经胶质细胞胶质细胞酸性蛋白(GFAP)表达的影响.结果:相对于假手术组,各手术组脊髓后角神经元c - FOS蛋白表达明显增高,GFAP染色阳性星形胶质细胞明显增生肥大.与模型组比较,脊髓背角c - FOS表达明显降低(P<0.05),GFAP表达变化改善.结论:外用中药对骨转移癌疼痛模型有明显镇痛作用,作用机制与拮抗伤害感受器并且抑制痛觉在脊髓水平的放大有关.%Objective: Evaluate the anti - - nociceptive effects of herbal medicine extraction in a rat model of bone cancer pain. Melluids:Following Medhursts method,a rat model of cancer - induced bone pain was established using the MRMT - 1 cell line. The corresponding segments of the ipsilateral spinal cord were processed for c - fos staining and glial fihrillary acidic protein{ GFAP)staining. Results:Compared to sham - operation group,c - fos and GFAP expression in the spinal cord dorsal horn of the model group was significantly increased. Compared to model group, treatment with herbal medicine extraction( ad us. Ext )significantly inhibited c - fos expression( P<0.05) ,GKAP exprcssion was also attenuated. Conclusions:The herbal medicine extraction is an anti - nociceptive agent in a rat model of metastatic cancer pain.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Neuronal hyperexcitability in the dorsal horn after painful facet joint injury

    OpenAIRE

    2010-01-01

    Excessive cervical facet capsular ligament stretch has been implicated as a cause of whiplash-associated disorders following rear-end impacts, but the pathophysiological mechanisms that produce chronic pain in these cases remain unclear. Using a rat model of C6/C7 cervical facet joint capsule stretch that produces sustained mechanical hyperalgesia, the presence of neuronal hyperexcitability was characterized 7 days after joint loading. Extracellular recordings of spinal dorsal horn neuronal a...

  20. Modulation of synaptic transmission from segmental afferents by spontaneous activity of dorsal horn spinal neurones in the cat.

    Science.gov (United States)

    Manjarrez, E; Rojas-Piloni, J G; Jimenez, I; Rudomin, P

    2000-12-01

    We examined, in the anaesthetised cat, the influence of the neuronal ensembles producing spontaneous negative cord dorsum potentials (nCDPs) on segmental pathways mediating primary afferent depolarisation (PAD) of cutaneous and group I muscle afferents and on Ia monosynaptic activation of spinal motoneurones. The intraspinal distribution of the field potentials associated with the spontaneous nCDPs indicated that the neuronal ensembles involved in the generation of these potentials were located in the dorsal horn of lumbar segments, in the same region of termination of low-threshold cutaneous afferents. During the occurrence of spontaneous nCDPs, transmission from low-threshold cutaneous afferents to second order neurones in laminae III-VI, as well as transmission along pathways mediating PAD of cutaneous and Ib afferents, was facilitated. PAD of Ia afferents was instead inhibited. Monosynaptic reflexes of flexors and extensors were facilitated during the spontaneous nCDPs. The magnitude of the facilitation was proportional to the amplitude of the 'conditioning' spontaneous nCDPs. This led to a high positive correlation between amplitude fluctuations of spontaneous nCDPs and fluctuations of monosynaptic reflexes. Stimulation of low-threshold cutaneous afferents transiently reduced the probability of occurrence of spontaneous nCDPs as well as the fluctuations of monosynaptic reflexes. It is concluded that the spontaneous nCDPs were produced by the activation of a population of dorsal horn neurones that shared the same functional pathways and involved the same set of neurones as those responding monosynaptically to stimulation of large cutaneous afferents. The spontaneous activity of these neurones was probably the main cause of the fluctuations of the monosynaptic reflexes observed under anaesthesia and could provide a dynamic linkage between segmental sensory and motor pathways.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Selective depression of nociceptive responses of dorsal horn neurones by SNC 80 in a perfused hindquarter preparation of adult mouse.

    Science.gov (United States)

    Cao, C Q; Hong, Y G; Dray, A; Perkins, M N

    2001-01-01

    Detailed electrophysiological characterisation of spinal opioid receptors in the mouse has been limited due to various technical difficulties. In this study, extracellular single unit recordings were made from dorsal horn neurones in a perfused spinal cord with attached trunk-hindquarter to investigate the role of delta-opioid receptor in mediating nociceptive and non-nociceptive transmission in mouse. Noxious electrical shock, pinch and heat stimuli evoked a mean response of 20.8+/-2.5 (n=10, PSNC 80) was perfused for 8-10 min, these evoked nociceptive responses were reversibly depressed. SNC 80 (2 microM) depressed the nociceptive responses evoked by electrical shock, pinch and heat by 74.0+/-13.7% (n=8, PSNC 80 was 92.6+/-6.8% (n=3). SNC 80 at 5 microM also completely abolished the wind-up and/or hypersensitivity (n=5). The depressant effects of SNC 80 on the nociceptive responses were completely blocked by 10 microM naloxone (n=5) and 3 microM 17-(cyclopropylmethyl)-6,7-dehydro-4,5 alpha-epoxy-14 beta-ethoxy-5 beta-methylindolo [2',3':6',7'] morphinan-3-ol hydrochloride (HS 378, n=8), a novel highly selective delta-opioid receptor antagonist. Interestingly, HS 378 (3 microM) itself potentiated the background activity and evoked responses to pinch and heat by 151.8+/-38.4% (PSNC 80 at a dose of up to 10 microM (n=5). These data demonstrate that delta-opioid receptor modulate nociceptive, but not non-nociceptive, transmission in spinal dorsal horn neurones of the adult mouse. The potentiation of neuronal activity by HS 378 may reflect an autoregulatory role of the endogenous delta-opioid in nociceptive transmission in mouse.

  3. Cholinergic modulation of primary afferent glutamatergic transmission in rat medullary dorsal horn neurons.

    Science.gov (United States)

    Jeong, Seok-Gwon; Choi, In-Sun; Cho, Jin-Hwa; Jang, Il-Sung

    2013-12-01

    Although muscarinic acetylcholine (mACh) receptors are expressed in trigeminal ganglia, it is still unknown whether mACh receptors modulate glutamatergic transmission from primary afferents onto medullary dorsal horn neurons. In this study, we have addressed the cholinergic modulation of primary afferent glutamatergic transmission using a conventional whole cell patch clamp technique. Glutamatergic excitatory postsynaptic currents (EPSCs) were evoked from primary afferents by electrical stimulation of trigeminal tract and monosynaptic EPSCs were recorded from medullary dorsal horn neurons of rat horizontal brain stem slices. Muscarine and ACh reversibly and concentration-dependently decreased the amplitude of glutamatergic EPSCs and increased the paired-pulse ratio. In addition, muscarine reduced the frequency of miniature EPSCs without affecting the current amplitude, suggesting that muscarine acts presynaptically to decrease the probability of glutamate release onto medullary dorsal horn neurons. The muscarine-induced decrease of glutamatergic EPSCs was significantly occluded by methoctramine or AF-DX116, M2 receptor antagonists, but not pirenzepine, J104129 and MT-3, selective M1, M3 and M4 receptor antagonists. The muscarine-induced decrease of glutamatergic EPSCs was highly dependent on the extracellular Ca2+ concentration. Physostigmine and clinically available acetylcholinesterase inhibitors, such as rivastigmine and donepezil, significantly shifted the concentration-inhibition relationship of ACh for glutamatergic EPSCs. These results suggest that muscarine acts on presynaptic M2 receptors to inhibit glutamatergic transmission by reducing the Ca2+ influx into primary afferent terminals, and that M2 receptor agonists and acetylcholinesterase inhibitors could be, at least, potential targets to reduce nociceptive transmission from orofacial tissues.

  4. Convergent nociceptive input to spinal dorsal horn neurons after peripheral nerve injury.

    Science.gov (United States)

    Terayama, Ryuji; Kishimoto, Noriko; Yamamoto, Yuya; Maruhama, Kotaro; Tsuchiya, Hiroki; Mizutani, Masahide; Iida, Seiji; Sugimoto, Tomosada

    2015-03-01

    The number of c-Fos protein-like immunoreactive (c-Fos-IR) neurons in the spinal dorsal horn evoked by noxious stimulation was previously shown to be increased following peripheral nerve injury, and this increase was proposed to reflect the neuropathic pain state. The aim of this study was to investigate whether anomalous convergent primary afferent input to spinal dorsal horn neurons contributed to nerve injury-induced c-Fos hyperinducibility. Double immunofluorescence labeling for c-Fos and phosphorylated extracellular signal-regulated kinase (p-ERK) was performed to detect convergent synaptic input from different branches of the sciatic nerve after injury to the tibial nerve. c-Fos expression and the phosphorylation of ERK were induced by noxious heat stimulation of the hindpaw and also by electrical stimulation (ES) of the injured tibial nerve, respectively. The number of c-Fos-IR neurons was significantly decreased 3 days after the injury. However, the number of c-Fos-IR neurons returned to the control level 14 days after the injury. P-ERK immunoreactive (p-ERK-IR) neurons were induced in the central terminal field of the tibial nerve by ES of the tibial nerve. The topographic distribution pattern and number of such p-ERK-IR neurons remained unchanged after the nerve injury. The time course of changes in the number of double-labeled neurons, that presumably received convergent primary afferent input, showed a pattern similar to that of c-Fos-IR neurons after the injury. These results indicate that convergent primary nociceptive input through neighboring intact nerves may contribute to c-Fos hyperinducibility in the spinal dorsal horn.

  5. Intradermal endothelin-1 excites bombesin-responsive superficial dorsal horn neurons in the mouse.

    Science.gov (United States)

    Akiyama, T; Nagamine, M; Davoodi, A; Iodi Carstens, M; Cevikbas, F; Steinhoff, M; Carstens, E

    2015-10-01

    Endothelin-1 (ET-1) has been implicated in nonhistaminergic itch. Here we used electrophysiological methods to investigate whether mouse superficial dorsal horn neurons respond to intradermal (id) injection of ET-1 and whether ET-1-sensitive neurons additionally respond to other pruritic and algesic stimuli or spinal superfusion of bombesin, a homolog of gastrin-releasing peptide (GRP) that excites spinal itch-signaling neurons. Single-unit recordings were made from lumbar dorsal horn neurons in pentobarbital-anesthetized C57BL/6 mice. We searched for units that exhibited elevated firing after id injection of ET-1 (1 μg/μl). Responsive units were further tested with mechanical stimuli, bombesin (spinal superfusion, 200 μg·ml(-1)·min(-1)), heating, cooling, and additional chemicals [histamine, chloroquine, allyl isothiocyanate (AITC), capsaicin]. Of 40 ET-1-responsive units, 48% responded to brush and pinch [wide dynamic range (WDR)] and 52% to pinch only [high threshold (HT)]. Ninety-three percent responded to noxious heat, 50% to cooling, and >70% to histamine, chloroquine, AITC, and capsaicin. Fifty-seven percent responded to bombesin, suggesting that they participate in spinal itch transmission. That most ET-1-sensitive spinal neurons also responded to pruritic and algesic stimuli is consistent with previous studies of pruritogen-responsive dorsal horn neurons. We previously hypothesized that pruritogen-sensitive neurons signal itch. The observation that ET-1 activates nociceptive neurons suggests that both itch and pain signals may be generated by ET-1 to result in simultaneous sensations of itch and pain, consistent with observations that ET-1 elicits both itch- and pain-related behaviors in animals and burning itch sensations in humans.

  6. The pain pathway in the rat following noxious thermal stimulation: effect of morphine on pERK1/2 and TRPV1 at the dorsal horn level, and on hyperalgesia.

    Science.gov (United States)

    Donnerer, Josef; Liebmann, Ingrid

    2013-01-01

    The aim of the present study was to investigate the phosphorylation of ERK1/2 in the lumbar dorsal horn of the rat by fluorescence immunohistochemistry following a noxious thermal stimulation of the hind paw. The protein level of TRPV1 in the dorsal spinal cord and the development of a heat hyperalgesia after the acute noxious thermal stimulation were also measured. The protein content of TRPV1 was determined by Western blot and heat hyperalgesia by the plantar test. At 2 and 10 min after the thermal stimulation a 4-fold increase in pERK1/2 immunoreactivity was observed in cells of lamina I/II of the L3-L5 dorsal horn. A pretreatment with the opioid analgesic morphine markedly attenuated ERK1/2 phosphorylation. The protein content of TRPV1 in the lumbar dorsal spinal cord was not significantly altered at 1 and 4 h after the thermal hind paw stimulation and by the morphine pretreatment. Heat hyperalgesia in the plantar test was observed at 8 h, but not at 24 h after the noxious stimulation. This temporary hyperalgesia was prevented by the morphine pretreatment. The present findings indicate that ERK1/2 activation in dorsal horn nociceptive neurons may be linked to the development of hyperalgesia, and that opioid analgesics are effective agents to prevent sensitization in the pain pathway at spinal level.

  7. Excitation of dorsal root fibers in spinal cord stimulation: a theoretical study

    NARCIS (Netherlands)

    Struijk, Johannes J.; Holsheimer, Jan; Boom, Herman B.K.

    1993-01-01

    In epidural spinal cord stimulation it is likely not only that dorsal column fibers are activated, but also that dorsal root fibers will be involved as well. In this investigation a volume conductor model of the spinal cord was used and dorsal root fibers were modeled by an electrical network includ

  8. Changes in response properties of nociceptive dorsal horn neurons in a murine model of cancer pain

    Institute of Scientific and Technical Information of China (English)

    Donald A. Simone; Sergey G. Khasabov; Darryl T. Hamamoto

    2008-01-01

    Pain associated with cancer that metastasizes to bone is often severe and debilitating. A better understanding of the neural mechanisms that mediate cancer pain is needed for the development of more effective treatments. In this study, we used an established model of cancer pain to characterize changes in response properties of dorsal horn neurons. Fibrosarcoma cells were implanted into and around the calcaneus bone in mice and extracellular electrophysiological recordings were made from wide dynamic range (WDR) and high threshold (HT) dorsal horn neurons. Responses of WDR and HT neurons evoked by mechanical, heat, and cold stimuli applied to the plantar surface of the hind paw were compared between tumor bearing mice and control mice. Mice exhibited hyperalgesia to mechanical and heat stimuli applied to their tumor-bearing hind paw. WDR neurons in tumor-beating mice exhibited an increase in spontaneous activity, and enhanced responses to mechanical, heat, and cold stimuli as compared to controls. Our findings show that sensitization of WDR neurons, but not HT neurons, contributes to tumor-evoked hyperalgesia.

  9. Identification of cerebellin2 in chick and its preferential expression by subsets of developing sensory neurons and their targets in the dorsal horn.

    Science.gov (United States)

    Yang, Mao; Cagle, Michael C; Honig, Marcia G

    2010-07-15

    The cerebellins are a family of four secreted proteins, two of which, Cbln1 and Cbln3, play an important role in the formation and maintenance of parallel fiber-Purkinje cell synapses. We have identified the chicken homologue of Cbln2 and, through the use of in situ hybridization, shown that it is expressed by specific subsets of neurons in the dorsal root ganglia (DRGs) and spinal cord starting shortly after those neurons are generated. In the developing spinal cord, Cbln2 is highly expressed by dI1, dI3, dI5, and dILB dorsal interneurons and to a lesser extent by dI2, dI4, dI6, and dILA dorsal interneurons, but not by ventral (v0-v3) interneurons. After the spinal cord has matured and neurons have migrated to their final destinations, Cbln2 is abundant in the dorsal horn. In the DRGs, Cbln2 is expressed by TrkB+ and TrkC+ sensory neurons, but not by TrkA+ sensory neurons. Interestingly, regions of the spinal cord where TrkB+ and TrkC+ afferents terminate (i.e., laminae II, III, IV, and VI) exhibit the highest levels of Cbln2 expression. Cbln2 is also expressed by preganglionic sympathetic neurons and their targets in the sympathetic chain ganglia. Thus, the results show that Cbln2 is frequently expressed by synaptically connected neuronal populations. This, in turn, raises the possibility that if Cbln2, like Cbln1, plays a role in the formation and maintenance of synapses, it may somehow mediate bi-directional communication between discrete populations of neurons and their appropriate neuronal targets.

  10. Differentiation of the nuclear groups in the posterior horn of the human embryonic spinal cord.

    Science.gov (United States)

    Pytel, A; Bruska, M; Woźniak, W

    2011-11-01

    The formation of nuclear groups in the posterior horns of the human embryonic spinal cord was traced in serial sections of embryos of developmental stages 13 to 23 (32 to 56 postovulatory days). The following observations, new for the human, are presented: 1. The differentiation of the neural tube into 3 zones (germinal, mantle and marginal) is detected in the middle of the 5(th) week. 2. The primordia of the posterior horns are marked at stage 14 (33 days). 3. In the middle of the 7(th) week the nucleus proprius and substantia gelatinosa are discerned. 4. Differentiation of the nuclei within the posterior horns proceeds in the ventrodorsal and rostrocaudal gradients.

  11. Change of pannexin1 expression in dorsal horn of spinal cord in rats with neuropathic pain%缝隙连接蛋白pannexin1在神经病理性疼痛大鼠脊髓背角的表达变化

    Institute of Scientific and Technical Information of China (English)

    周功锐; 包晓航; 毛庆祥; 龙宗泓; 景胜; 黄静; 杨天德

    2015-01-01

    Objective To observe the expression of pannexin1(PX1) in the dorsal horn of spinal cord in model ratwith neu-ropathipain afteselective ligation of sciatinerve branche.Method50 male SD ratwere randomly divided into 3 group,inclu-ding the control group(Wgroup ,n= 10) ,sham operation group(sham group ,n= 10) and sciatinerve branch selective injury group(SNI group ,n=30) .30 ratwere killed on postoperative 3 ,5 ,7 ,14 d and the lumbasegmenof the spinal cord wataken fodetecting the expression of PX1 by using Western blo.Othe20 ratwere killed on 7 d afteSNI and the expression of glial fibril-lary acidiprotein(GFAP) in the spinal cord wadetected with immunohistology .Among them ,10 ratin the SNI group were trea-ted with intrathecal intubation before operation and administrated with saline 20 μL ocarbenoxolone(CBX) 20 μL by intrathecal injection on postoperative 7 d fodetermining the expression of GFAP by the immunohistology .ResultThe expression of PX1 in the SNI group waincreased and enhanced with time ,which wasignificantly highethan thain the Wgroup and the sham group (P<0 .05);the GFAP expression on 7 d in the SNI group waobviously increased compared with the Wgroup and the sham group(P<0 .05);afteintrathecal injection of CBX ,the expression of GFAP wasignificantly decreased compared with thain the normal saline group(P<0 .05) .No statistically significandifferencein the expression of PX1 and GFAP were found in the Wgroup and the sham group .Conclusion PX1 may be involved in the activation of astrocyte,prompting thaPX1 playan importanrole in the neuropathipain caused by the peripheral nervel injury .%目的 观察缝隙连接蛋白pannexin1(PX1)在坐骨神经分支选择结扎模型大鼠脊髓背角上的表达变化.方法 健康SD雄性大鼠50只 ,分为对照组(WT组 ,n=10)、假手术组(sham组 ,n=10)和坐骨神经分支选择性损伤组(SNI组 ,n=30).SNI组20只大鼠于术后3、5、7、14 d(n=5) ,WT、sham组于术后14 d(n=5)

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

    Directory of Open Access Journals (Sweden)

    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. Long-term effects of brain-derived neurotrophic factor on the frequency of inhibitory synaptic events in the rat superficial dorsal horn.

    Science.gov (United States)

    Lu, V B; Colmers, W F; Smith, P A

    2009-07-21

    Chronic constriction injury (CCI) of rat sciatic nerve produces a specific pattern of electrophysiological changes in the superficial dorsal horn that lead to central sensitization that is associated with neuropathic pain. These changes can be recapitulated in spinal cord organotypic cultures by long term (5-6 days) exposure to brain-derived neurotrophic factor (BDNF) (200 ng/ml). Certain lines of evidence suggest that both CCI and BDNF increase excitatory synaptic drive to putative excitatory neurons while reducing that to putative inhibitory interneurons. Because BDNF slows the rate of discharge of synaptically-driven action potentials in inhibitory neurons, it should also decrease the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) throughout the superficial dorsal horn. To test this possibility, we characterized superficial dorsal horn neurons in organotypic cultures according to five electrophysiological phenotypes that included tonic, delay and irregular firing neurons. Five to 6 days of treatment with 200 ng/ml BDNF decreased sIPSC frequency in tonic and irregular neurons as might be expected if BDNF selectively decreases excitatory synaptic drive to inhibitory interneurons. The frequency of sIPSCs in delay neurons was however increased. Further analysis of the action of BDNF on tetrodotoxin-resistant miniature inhibitory postsynaptic currents (mIPSC) showed that the frequency was increased in delay neurons, unchanged in tonic neurons and decreased in irregular neurons. BDNF may thus reduce action potential frequency in those inhibitory interneurons that project to tonic and irregular neurons but not in those that project to delay neurons.

  14. P2X7受体拮抗剂A438079对肠易激综合征结肠扩张刺激大鼠DCN核团中P2X7、OX42、IL-1β、P38及骶髓后角中CGRP表达的影响%Effect of P2X7 receptor antagonist A438079 on expression of P2X7,OX42,IL-1β,P38 in dorsal commissural nucleus and CGRP expression in dorsal horn of sacral segment of spinal cord in rats with irritable bowel syndrome

    Institute of Scientific and Technical Information of China (English)

    朱琳; 章鹏宇; 黄裕新; 王景杰

    2012-01-01

    目的 探讨P2X7特异性受体拮抗剂A438079对肠易激综合征(irritable bowel syndrome,IBS)致内脏高敏感化大鼠在结肠扩张刺激状态时,骶髓后联合核(dorsal commissural nucleus,DCN)中P2X7、OX42、IL-1β、P38及脊髓背角中CGRP表达的变化,为探讨IBS内脏敏化的神经机制提供理论依据.方法 以15只旋毛虫感染大鼠建立肠易激综合征模型,随机分为三组,总共分为:B.IBS大鼠结肠扩张刺激组(n=5)、C.IBS大鼠鞘内注射0.9%生理盐水后结肠扩张刺激组(n=5)、D.IBS大鼠鞘内注射A438079后结肠扩张刺组(n=5).另外以5只正常大鼠作正常大鼠结肠扩张刺激组(n=5)、.采用免疫荧光组织化学方法观察大鼠DCN中P2X7、OX42、IL-1β、P38及脊髓后角中CGRP表达变化.结果 与B组IBS扩张刺激组相比较,D组鞘内注射拮抗剂A438079后在结肠扩张刺激时IBS大鼠DCN核团中P2X7、OX42、IL-1β、P38及骶髓后角中CGRP的表达量均明显下降(P<0.01).结论 P2X7受体在IBS致内脏敏化过程中广泛参与,并可能起重要作用.%Objective To explore the effect of A438079, a P2X7 receptor antagonist, on expression of P2X7 , 0x42, IL-1 β, P38 in dorsal commissural nucleus and calcitonin gene related peptide( CGRP ) in dorsal horn of sacral segment of spinal cord in rats with irritable bowel syndrome ( IBS ) induced by the stimulation of colorectal distention, and to provide a theoretical evidence in the prevention and treatment of IBS. Methods Fifteen rats were gavaged with the Trichinella spiralis to establish the IBS model, and then were divided into three groups: IBS + colon distension group ( B ), IBS + colon distension + intrathecal injection of saline ( C ), and IBS + colon distension + intrathecal injection of A438079( D ). Five normal rats with colon distension were chosen as control group. Immunofluorescent staining method was used to observe the expression of P2X7,OX42,I L-1β,P38 in neurons of DCN and CGRP expression in

  15. Development of regional specificity of spinal and medullary dorsal horn neurons

    Institute of Scientific and Technical Information of China (English)

    Yu-Feng Xie; Xing-Hong Jiang; Barry J Sessle; Xian-Min Yu

    2016-01-01

    Extensive studies have focused on the development and regionalization of neurons in the central nervous system(CNS). Many genes, which play crucial roles in the development of CNS neurons, have been identified. By using the technique "direct reprogramming", neurons can be produced from multiple cell sources such as fibroblasts. However, understanding the region-specific regulation of neurons in the CNS is still one of the biggest challenges in the research field of neuroscience. Neurons located in the trigeminal subnucleus caudalis(Vc) and in the spinal dorsal horn(SDH) play crucial roles in pain and sensorimotor functions in the orofacial and other somatic body regions, respectively. Anatomically, Vc represents the most caudal component of the trigeminal system, and is contiguous with SDH. This review is focused on recent data dealing with the regional specificity involved in the development of neurons in Vc and SDH.

  16. Oscillatory interaction between dorsal root excitability and dorsal root potentials in the spinal cord of the turtle

    DEFF Research Database (Denmark)

    Delgado-Lezama, R; Perrier, J F; Hounsgaard, J

    1999-01-01

    . The oscillating response could only be evoked from stimulus sites to which dorsal root potentials were conducted from the spinal cord (2-3 mm). At more distant stimulus sites cyclic variations in amplitude of the cord dorsum potential and the synaptic response in motoneurons were not observed. During...

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

    Science.gov (United States)

    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.

  18. Subpopulations of PKCγ interneurons within the medullary dorsal horn revealed by electrophysiologic and morphologic approach.

    Science.gov (United States)

    Alba-Delgado, Cristina; El Khoueiry, Corinne; Peirs, Cédric; Dallel, Radhouane; Artola, Alain; Antri, Myriam

    2015-09-01

    Mechanical allodynia, a cardinal symptom of persistent pain, is associated with the unmasking of usually blocked local circuits within the superficial spinal or medullary dorsal horn (MDH) through which low-threshold mechanical inputs can gain access to the lamina I nociceptive output neurons. Specific interneurons located within inner lamina II (IIi) and expressing the gamma isoform of protein kinase C (PKCγ⁺) have been shown to be key elements for such circuits. However, their morphologic and electrophysiologic features are still unknown. Using whole-cell patch-clamp recordings and immunohistochemical techniques in slices of adult rat MDH, we characterized such lamina IIi PKCγ⁺ interneurons and compared them with neighboring PKCγ⁻ interneurons. Our results reveal that PKCγ⁺ interneurons display very specific activity and response properties. Compared with PKCγ⁻ interneurons, they exhibit a smaller membrane input resistance and rheobase, leading to a lower threshold for action potentials. Consistently, more than half of PKCγ⁺ interneurons respond with tonic firing to step current. They also receive a weaker excitatory synaptic drive. Most PKCγ⁺ interneurons express Ih currents. The neurites of PKCγ⁺ interneurons arborize extensively within lamina IIi, can spread dorsally into lamina IIo, but never reach lamina I. In addition, at least 2 morphologically and functionally different subpopulations of PKCγ⁺ interneurons can be identified: central and radial PKCγ⁺ interneurons. The former exhibit a lower membrane input resistance, rheobase and, thus, action potential threshold, and less PKCγ⁺ immunoreactivity than the latter. These 2 subpopulations might thus differently contribute to the gating of dorsally directed circuits within the MDH underlying mechanical allodynia.

  19. Acetaminophen Metabolite N-Acylphenolamine Induces Analgesia via Transient Receptor Potential Vanilloid 1 Receptors Expressed on the Primary Afferent Terminals of C-fibers in the Spinal Dorsal Horn.

    Science.gov (United States)

    Ohashi, Nobuko; Uta, Daisuke; Sasaki, Mika; Ohashi, Masayuki; Kamiya, Yoshinori; Kohno, Tatsuro

    2017-08-01

    The widely used analgesic acetaminophen is metabolized to N-acylphenolamine, which induces analgesia by acting directly on transient receptor potential vanilloid 1 or cannabinoid 1 receptors in the brain. Although these receptors are also abundant in the spinal cord, no previous studies have reported analgesic effects of acetaminophen or N-acylphenolamine mediated by the spinal cord dorsal horn. We hypothesized that clinical doses of acetaminophen induce analgesia via these spinal mechanisms. We assessed our hypothesis in a rat model using behavioral measures. We also used in vivo and in vitro whole cell patch-clamp recordings of dorsal horn neurons to assess excitatory synaptic transmission. Intravenous acetaminophen decreased peripheral pinch-induced excitatory responses in the dorsal horn (53.1 ± 20.7% of control; n = 10; P N-acylphenolamine decreased the amplitudes of monosynaptic excitatory postsynaptic currents evoked by C-fiber stimulation (control, 462.5 ± 197.5 pA; N-acylphenolamine, 272.5 ± 134.5 pA; n = 10; P = 0.022) but not those evoked by stimulation of Aδ-fibers. These phenomena were mediated by transient receptor potential vanilloid 1 receptors, but not cannabinoid 1 receptors. The analgesic effects of acetaminophen and N-acylphenolamine were stronger in rats experiencing an inflammatory pain model compared to naïve rats. Our results suggest that the acetaminophen metabolite N-acylphenolamine induces analgesia directly via transient receptor potential vanilloid 1 receptors expressed on central terminals of C-fibers in the spinal dorsal horn and leads to conduction block, shunt currents, and desensitization of these fibers.

  20. In vivo electrochemical monitoring of serotonin in spinal dorsal horn with Nafion-coated multi-carbon fiber electrodes.

    Science.gov (United States)

    Rivot, J P; Cespuglio, R; Puig, S; Jouvet, M; Besson, J M

    1995-09-01

    Biosensors sensitive for in vivo monitoring of serotonin (5-HT) in the CNS by differential normal pulse voltammetry were constructed by coating treated multicarbon fiber electrodes (mCFEs) with Nafion (N-mCFE). In vitro sensitivities of mCFE and N-mCFE were compared in solutions ranging from 5 nM to 20 microM of uric acid (UA), 5-hydroxyindoleacetic acid (5-HIAA), and 5-HT. The mCFEs were three to seven times less sensitive for 5-HIAA or UA than for 5-HT. Nafion treatment dramatically decreased sensitivity for 5-HIAA and UA of N-mCFEs (approximately 10(3) times), whereas it remained in the nanomolar range for 5-HT. In vivo, in the dorsal horn of the lumbar spinal cord of anesthetized rats, the monoamine oxidase inhibitor clorgyline (10 mg/kg i.p.) produced a reduction (55 +/- 3% at 180 min) of peak 3 of oxidation current (characteristic of 5-hydroxyindoles) monitored with mCFEs, but with N-mCFEs (in this latter case the peak was termed 3N) peak 3N increased to 135 +/- 5% at 180 min. The 5-HT release-inducer p-chloroamphetamine (PCA; 6 mg/kg i.p.) induced a slight (12 +/- 3% at 150 min) decrease in peak 3 measured with mCFEs, whereas with N-mCFEs PCA induced a rapid increase of peak 3N (137 +/- 6% at 90 min). The xanthine oxidase inhibitor allopurinol (10 mg/kg i.p.) produced a decrease (30 +/- 3% at 180 min) in peak 3 (mCFEs), but peak 3N (N-mCFEs) was not affected (106% at 180 min). After pretreatment with allopurinol, PCA also produced an increase (135 +/- 6% at 90 min) in peak 3N.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Input-output mapping reconstruction of spike trains at dorsal horn evoked by manual acupuncture

    Science.gov (United States)

    Wei, Xile; Shi, Dingtian; Yu, Haitao; Deng, Bin; Lu, Meili; Han, Chunxiao; Wang, Jiang

    2016-12-01

    In this study, a generalized linear model (GLM) is used to reconstruct mapping from acupuncture stimulation to spike trains driven by action potential data. The electrical signals are recorded in spinal dorsal horn after manual acupuncture (MA) manipulations with different frequencies being taken at the “Zusanli” point of experiment rats. Maximum-likelihood method is adopted to estimate the parameters of GLM and the quantified value of assumed model input. Through validating the accuracy of firings generated from the established GLM, it is found that the input-output mapping of spike trains evoked by acupuncture can be successfully reconstructed for different frequencies. Furthermore, via comparing the performance of several GLMs based on distinct inputs, it suggests that input with the form of half-sine with noise can well describe the generator potential induced by acupuncture mechanical action. Particularly, the comparison of reproducing the experiment spikes for five selected inputs is in accordance with the phenomenon found in Hudgkin-Huxley (H-H) model simulation, which indicates the mapping from half-sine with noise input to experiment spikes meets the real encoding scheme to some extent. These studies provide us a new insight into coding processes and information transfer of acupuncture.

  2. Nociceptive input from the rat thoracolumbar fascia to lumbar dorsal horn neurones.

    Science.gov (United States)

    Hoheisel, Ulrich; Taguchi, Toru; Treede, Rolf-Detlef; Mense, Siegfried

    2011-09-01

    In anaesthetised rats, systematic electrophysiological recordings from dorsal horn neurones in spinal segments Th13-L5 were made to obtain information about the spinal nociceptive processing from the lumbar thoracolumbar fascia. Six to fourteen percent of the neurones in the spinal segments Th13-L2 had nociceptive input from the thoracolumbar fascia in naïve animals, no neurones responsive to input from the lumbar fascia were found in segments L3-L5. The segmental location of the receptive fields in the fascia was shifted 2-4 segments caudally relative to the spinal segment recorded from. Most neurones were convergent in that they received additional input from other deep somatic tissues in the low back (87%) and from the skin in the abdominal wall or the proximal leg (50%). The proportion of neurones responsive to input from the thoracolumbar fascia rose significantly from 4% to 15% (Pfascia in normal animals - responded to fascia input in animals with inflamed muscle. The data suggest that the nociceptive input from the thoracolumbar fascia contributes to the pain in low back pain patients.

  3. Amitriptyline and carbamazepine utilize voltage-gated ion channel suppression to impair excitability of sensory dorsal horn neurons in thin tissue slice: An in vitro study.

    Science.gov (United States)

    Wolff, Matthias; Czorlich, Patrick; Nagaraj, Chandran; Schnöbel-Ehehalt, Rose; Li, Yingji; Kwapiszewska, Grazyna; Olschewski, Horst; Heschl, Stefan; Olschewski, Andrea

    2016-08-01

    Amitriptyline, carbamazepine and gabapentin are often used for the treatment of neuropathic pain. However, their analgesic action on central sensory neurons is still not fully understood. Moreover, the expression pattern of their target ion channels is poorly elucidated in the dorsal horn of the spinal cord. Thus, we performed patch-clamp investigations in visualized neurons of lamina I-III of the spinal cord. The expression of the different voltage-gated ion channels, as the targets of these drugs, was detected by RT-PCR and immunohistochemistry. Neurons of the lamina I-III express the TTX-sensitive voltage-gated Na(+) as well as voltage-gated K(+) subunits assembling the fast inactivating (A-type) currents and the delayed rectifier K(+) currents. Our pharmacological studies show that tonically-firing, adapting-firing and single spike neurons responded dose-dependently to amitriptyline and carbamazepine. The ion channel inhibition consecutively reduced the firing rate of tonically-firing and adapting-firing neurons. This study provides evidence for the distribution of voltage-gated Na(+) and K(+) subunits in lamina I-III of the spinal cord and for the action of drugs used for the treatment of neuropathic pain. Our work confirms that modulation of voltage-gated ion channels in the central nervous system contributes to the antinociceptive effects of these drugs.

  4. Kv3.1b and Kv3.3 channel subunit expression in murine spinal dorsal horn GABAergic interneurones

    OpenAIRE

    Nowak, A; Mathieson, H.R.; Chapman, R.J.; Janzsó, G.; Yanagawa, Y; Obata, K.; Szabo, G.; King, A. E.

    2011-01-01

    GABAergic interneurones, including those within spinal dorsal horn, contain one of the two isoforms of the synthesizing enzyme glutamate decarboxylase (GAD), either GAD65 or GAD67. The physiological significance of these two GABAergic phenotypes is unknown but a more detailed anatomical and functional characterization may help resolve this issue. In this study, two transgenic Green Fluorescent Protein (GFP) knock-in murine lines, namely GAD65-GFP and GAD67-GFP (Δneo) mice, were used to profil...

  5. Is BDNF sufficient for information transfer between microglia and dorsal horn neurons during the onset of central sensitization?

    OpenAIRE

    2010-01-01

    Abstract Peripheral nerve injury activates spinal microglia. This leads to enduring changes in the properties of dorsal horn neurons that initiate central sensitization and the onset of neuropathic pain. Although a variety of neuropeptides, cytokines, chemokines and neurotransmitters have been implicated at various points in this process, it is possible that much of the information transfer between activated microglia and neurons, at least in this context, may be explicable in terms of the ac...

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

    Science.gov (United States)

    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

  7. 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

  8. Somatotopic organization of lumbar muscle-innervating neurons in the ventral horn of the rat spinal cord.

    Science.gov (United States)

    Takahashi, Yuzuru; Ohtori, Seiji; Takahashi, Kazuhisa

    2010-04-01

    The ventral horn of the rat spinal cord was investigated with respect to the somatotopic organization of the motor neurons that innervate the lumbar muscles. Neurotracer 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) was applied to specific sites in lumbar muscles. Spinal cord segments at L1 through L4 levels were cut into 40-mum serial transverse sections. Labeled neurons were located in the ventromedial nucleus (VM) and lateromedial nucleus (LM) nuclei of Rexed's lamina IX. Motor neurons innervating the m. interspinales lumborum and m. multifidus were without exception present in the VM, whereas all motor neurons innervating the m. rectus abdominis were present in the LM. Forty percent of motor neurons innervating the m. quadratus lumborum were present in the VM and the other 60% were in the LM. Although most of the motor neurons innervating the m. psoas major were present in the LM, a few labeled neurons existed in the VM. These results suggest that the border zone demarcating the areas of innervation of the dorsal and ventral rami of spinal nerves crosses the m. quadratus lumborum.

  9. 右美托咪啶对神经病理性痛大鼠脊髓背角pERK、c-fos表达的影响%Effection of dexmedetomidine on expression of pERK, C-FOS in spineal cord dorsal horn in a rat model of chronic neuropathic pain

    Institute of Scientific and Technical Information of China (English)

    高毅; 孙丽

    2015-01-01

    目的:评价右美托咪啶对神经病理性痛大鼠脊髓背角神经元磷酸化胞外反应激酶( phosphoryltion of extracellular reg-ulated protein kinases, pERK )、c-fos蛋白表达的影响。方法:健康成年雄性Wistar大鼠54只,6~8周龄,体重180~220 g,采用随机数字表法,将其分为3组(n=18):假手术组(S组)、慢性神经病理性痛组(C组)和右美托咪啶组(D组)。 S组仅分离坐骨神经但不结扎,C组和D组采用结扎坐骨神经的方法制备大鼠坐骨神经慢性压迫性损伤( chronic constriction injury, CCI)的神经病理性痛模型,D组于术后即刻开始至处死前1天腹腔注射右美托咪啶50μg/kg,1次/d,S组和C组注射等容量生理盐水。于术前1天、术后3、7、14天时以缩足阈值( paw withdrawal threshold, PWT)测定大鼠机械痛阈和辐射热的缩足潜伏期( paw withdrawl latency, PWL)测定大鼠的热痛阈,并于术后测定痛阈后灌注处死大鼠,取L4~6脊髓组织,采用免疫组织化学法检测脊髓背角神经元pERK、c-fos的表达水平。结果:与S组比较,C组和D组术后3、7、14天时MWT降低,TWL缩短,脊髓背角pERK、c-fos表达上调(P<0.05);与C组比较,D组术后3、7、14天时MWT升高,TWL延长,脊髓背角pERK、c-fos表达下调(P<0.05)。与术前1天比较,C组和D组术后3、7、14天时MWT降低,TWL缩短;与术后3天时比较,C组和D组7、14天时MWT降低,TWL缩短,脊髓背角pERK、c-fos表达上调( P<0.05)。结论:右美托咪啶可减轻大鼠慢性神经病理性痛,抑制pERK、c-fos的表达可能是其作用机制之一。%Objective:To investigate the effects of dexmedetomidine ( Dex) on the expression of pERK,c-fos in spinal dorsal horn in a rat model of chronic neuropathic pain ( CNP) .Methods:Fifty-four adult male wistar rats weighing 180~220 g were randomly divided

  10. Quantitative study of NPY-expressing GABAergic neurons and axons in rat spinal dorsal horn.

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    Polgár, Erika; Sardella, Thomas C P; Watanabe, Masahiko; Todd, Andrew J

    2011-04-15

    Between 25-40% of neurons in laminae I-III are GABAergic, and some of these express neuropeptide Y (NPY). We previously reported that NPY-immunoreactive axons form numerous synapses on lamina III projection neurons that possess the neurokinin 1 receptor (NK1r). The aims of this study were to determine the proportion of neurons and GABAergic boutons in this region that contain NPY, and to look for evidence that they selectively innervate different neuronal populations. We found that 4-6% of neurons in laminae I-III were NPY-immunoreactive and based on the proportions of neurons that are GABAergic, we estimate that NPY is expressed by 18% of inhibitory interneurons in laminae I-II and 9% of those in lamina III. GABAergic boutons were identified by the presence of the vesicular GABA transporter (VGAT) and NPY was found in 13-15% of VGAT-immunoreactive boutons in laminae I-II, and 5% of those in lamina III. For both the lamina III NK1r-immunoreactive projection neurons and protein kinase Cγ (PKCγ)-immunoreactive interneurons in lamina II, we found that around one-third of the VGAT boutons that contacted them were NPY-immunoreactive. However, based on differences in the sizes of these boutons and the strength of their NPY-immunoreactivity, we conclude that these originate from different populations of interneurons. Only 6% of VGAT boutons presynaptic to large lamina I projection neurons that lacked NK1rs contained NPY. These results show that NPY-containing neurons make up a considerable proportion of the inhibitory interneurons in laminae I-III, and that their axons preferentially target certain classes of dorsal horn neuron.

  11. Role of 5-HT1 receptor subtypes in the modulation of pain and synaptic transmission in rat spinal superficial dorsal horn

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    Jeong, Hyo-Jin; Mitchell, Vanessa A; Vaughan, Christopher W

    2012-01-01

    BACKGROUND AND PURPOSE 5-HT receptor agonists have variable nociceptive effects within the spinal cord. While there is some evidence for 5-HT1A spinally-mediated analgesia, the role of other 5-HT1 receptor subtypes remains unclear. In the present study, we examined the spinal actions of a range of 5-HT1 agonists, including sumatriptan, on acute pain, plus their effect on afferent-evoked synaptic transmission onto superficial dorsal horn neurons. EXPERIMENTAL APPROACH For in vivo experiments, 5-HT agonists were injected via chronically implanted spinal catheters to examine their effects in acute mechanical and thermal pain assays using a paw pressure analgesymeter and a Hargreave's device. For in vitro experiments, whole-cell patch-clamp recordings of primary afferent-evoked glutamatergic EPSC were made from lamina II neurons in rat lumbar spinal slices. KEY RESULTS Intrathecal (i.t.) delivery of the 5-HT1A agonist R ± 8-OH-DPAT (30–300 nmol) produced a dose-dependent thermal, but not mechanical, analgesia. Sumatriptan and the 5-HT1B, 5-HT1D, 5-HT1F agonists CP93129, PNU109291 and LY344864 (100 nmol) had no effect on either acute pain assay. R ± 8-OH-DPAT (1 µM) and sumatriptan (3 µM) both reduced the amplitude of the evoked EPSC. In contrast, CP93129, PNU109291 and LY344864 (0.3–3 µM) had no effect on the evoked EPSC. The actions of both R ± 8-OH-DPAT and sumatriptan were abolished by the 5-HT1A antagonist WAY100635 (3 µM). CONCLUSIONS AND IMPLICATIONS These findings indicate that the 5-HT1A receptor subtype predominantly mediates the acute antinociceptive and cellular actions of 5-HT1 ligands within the rat superficial dorsal horn. PMID:21950560

  12. 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

  13. Intravenous administration of lidocaine directly acts on spinal dorsal horn and produces analgesic effect: An in vivo patch-clamp analysis.

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    Kurabe, Miyuki; Furue, Hidemasa; Kohno, Tatsuro

    2016-05-18

    Intravenous lidocaine administration produces an analgesic effect in various pain states, such as neuropathic and acute pain, although the underlying mechanisms remains unclear. Here, we hypothesized that intravenous lidocaine acts on spinal cord neurons and induces analgesia in acute pain. We therefore examined the action of intravenous lidocaine in the spinal cord using the in vivo patch-clamp technique. We first investigated the effects of intravenous lidocaine using behavioural measures in rats. We then performed in vivo patch-clamp recording from spinal substantia gelatinosa (SG) neurons. Intravenous lidocaine had a dose-dependent analgesic effect on the withdrawal response to noxious mechanical stimuli. In the electrophysiological experiments, intravenous lidocaine inhibited the excitatory postsynaptic currents (EPSCs) evoked by noxious pinch stimuli. Intravenous lidocaine also decreased the frequency, but did not change the amplitude, of both spontaneous and miniature EPSCs. However, it did not affect inhibitory postsynaptic currents. Furthermore, intravenous lidocaine induced outward currents in SG neurons. Intravenous lidocaine inhibits glutamate release from presynaptic terminals in spinal SG neurons. Concomitantly, it hyperpolarizes postsynaptic neurons by shifting the membrane potential. This decrease in the excitability of spinal dorsal horn neurons may be a possible mechanism for the analgesic action of intravenous lidocaine in acute pain.

  14. Calretinin-immunoreactive nerves in the uterus, pelvic autonomic ganglia, lumbosacral dorsal root ganglia and lumbosacral spinal cord.

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    Papka, R E; Collins, J; Copelin, T; Wilson, K

    1999-10-01

    Nerves containing the calcium-binding protein calretinin have been reported in several organs but not in female reproductive organs and associated ganglia. This study was undertaken to determine if nerves associated with the uterus contain calretinin and the source(s) of calretinin-synthesizing nerves in the rat (are they sensory, efferent, or both?). Calretinin-immunoreactive nerves were present in the uterine horns and cervix where they were associated with arteries, uterine smooth muscle, glands, and the epithelium. Calretinin-immunoreactive terminals were apposed to neurons in the paracervical ganglia; in addition, some postganglionic neurons in this ganglion were calretinin positive. Calretinin perikarya were present in the lumbosacral dorsal root ganglia, no-dose ganglia, and lumbosacral spinal cord. Retrograde axonal tracing, utilizing Fluorogold injected into the uterus or paracervical parasympathetic ganglia, revealed calretinin-positive/Fluorogold-labeled neurons in the dorsal root and nodose ganglia. Also, capsaicin treatment substantially reduced the calretinin-positive fibers in the uterus and pelvic ganglia, thus indicating the sensory nature of these fibers. The presence of calretinin immunoreactivity identifies a subset of nerves that are involved in innervation of the pelvic viscera and have origins from lumbosacral dorsal root ganglia and vagal nodose ganglia. Though the exact function of calretinin in these nerves is not currently known, calretinin is likely to play a role in calcium regulation and their function.

  15. Pre- and postsynaptic localization of the 5-HT7 receptor in rat dorsal spinal cord: immunocytochemical evidence.

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    Doly, Stéphane; Fischer, Jacqueline; Brisorgueil, Marie-Jeanne; Vergé, Daniel; Conrath, Marie

    2005-09-26

    Several lines of evidence indicate that 5-HT7 receptors are involved in pain control at the level of the spinal cord, although their mechanism of action is poorly understood. To provide a morphological basis for understanding the action of 5-HT on this receptor, we performed an immunocytochemical study of 5-HT7 receptor distribution at the lumbar level. 5-HT7 immunolabelling is localized mainly in the two superficial laminae of the dorsal horn and in small and medium-sized dorsal root ganglion cells, which is consistent with a predominant role in nociception. In addition, moderate labelling is found in the lumbar dorsolateral nucleus (Onuf's nucleus), suggesting involvement in the control of pelvic floor muscles. Electron microscopic examination of the dorsal horn revealed three main localizations: 1) a postsynaptic localization on peptidergic cell bodies in laminae I-III and in numerous dendrites; 2) a presynaptic localization on unmyelinated and thin myelinated peptidergic fibers (two types of axon terminals are observed, large ones, presumably of primary afferent origin, and smaller ones partially from intrinsic cells; this presynaptic labelling represents 60% and 22% of total labelling in laminae I and II, respectively); and 3) 16.9% of labelling in lamina I and 19.8% in lamina II are observed in astrocytes. Labeled astrocytes are either intermingled with neuronal elements or make astrocytic "feet" on blood vessels. In dendrites, the labelling is localized on synaptic differentiations, suggesting that 5-HT may act synaptically on the 5-HT7 receptor. This localization is compared with other 5-HT receptor localizations, and their physiological consequences are discussed.

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

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    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

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

    Science.gov (United States)

    Ren, Ke; Novikova, Svetlana I; He, Fang; Dubner, Ronald; Lidow, Michael S

    2005-09-22

    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 neonatally-injured paw. The

  18. Kv3.1b and Kv3.3 channel subunit expression in murine spinal dorsal horn GABAergic interneurones.

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    Nowak, A; Mathieson, H R; Chapman, R J; Janzsó, G; Yanagawa, Y; Obata, K; Szabo, G; King, A E

    2011-09-01

    GABAergic interneurones, including those within spinal dorsal horn, contain one of the two isoforms of the synthesizing enzyme glutamate decarboxylase (GAD), either GAD65 or GAD67. The physiological significance of these two GABAergic phenotypes is unknown but a more detailed anatomical and functional characterization may help resolve this issue. In this study, two transgenic Green Fluorescent Protein (GFP) knock-in murine lines, namely GAD65-GFP and GAD67-GFP (Δneo) mice, were used to profile expression of Shaw-related Kv3.1b and Kv3.3 K(+)-channel subunits in dorsal horn interneurones. Neuronal expression of these subunits confers specific biophysical characteristic referred to as 'fast-spiking'. Immuno-labelling for Kv3.1b or Kv3.3 revealed the presence of both of these subunits across the dorsal horn, most abundantly in laminae I-III. Co-localization studies in transgenic mice indicated that Kv3.1b but not Kv3.3 was associated with GAD65-GFP and GAD67-GFP immunopositive neurones. For comparison the distributions of Kv4.2 and Kv4.3 K(+)-channel subunits which are linked to an excitatory neuronal phenotype were characterized. No co-localization was found between GAD-GFP +ve neurones and Kv4.2 or Kv4.3. In functional studies to evaluate whether either GABAergic population is activated by noxious stimulation, hindpaw intradermal injection of capsaicin followed by c-fos quantification in dorsal horn revealed co-expression c-fos and GAD65-GFP (quantified as 20-30% of GFP +ve population). Co-expression was also detected for GAD67-GFP +ve neurones and capsaicin-induced c-fos but at a much reduced level of 4-5%. These data suggest that whilst both GAD65-GFP and GAD67-GFP +ve neurones express Kv3.1b and therefore may share certain biophysical traits, their responses to peripheral noxious stimulation are distinct.

  19. Effects of Epidural Spinal Cord Stimulation and Treadmill Training on Locomotion Function and Ultrastructure of Spinal Cord Anterior Horn after Moderate Spinal Cord Injury in Rats

    Institute of Scientific and Technical Information of China (English)

    WANG Yizhao; HUANG Xiaolin; XU Jiang; XU Tao; FANG Zhengyu; XU Qi; TU Xikai; YANG Peipei

    2009-01-01

    Objective:To investigate the effects of epidural spinal cord stimulation (ESCS) and treadmill training on the locomotion function and ultrastructure of spinal cord anterior horn after moderate spinal cord injury in rats. (IT, n=3). All rats received a moderate spinal cord injury surgery. Four weeks after surgery, rats in SE group received an electrode implantation procedure, with the electrode field covering spinal cord segments L2-S1. Four weeks after electrode implantation, rats received subthreshold ESCS for 30 min/d. Rats in TY group received 4cm/s treadmill training for 30min/d. Rats in SI group received no intervention, as a control group. All procedures in these three groups lasted four weeks.The open field Basso,Beattie and Bresnahan (BBB) scale was used before and after intervention to evaluate rats' hindlimb motor function. Result:After four weeks intervention, rats in TT group improved their open field locomotion scores to 20. In contrast, no significant improvement was observed in groups SI and SE. The morphology of synapses and neurons were similar regardless of whether rats had undergone ESCS, treadmill training or not. Conclusion:ESCS alone was not sufficient to improve the walking ability of spinal cord injured rats. ESCS or treadmill training alone might not contribute to the changes of ultrastructure in anterior horn of spinal cord that underlie the recovery of walking ability. Further research is needed to understand the contributions of combination of ESCS and treadmill training to the rehabilitation of spinal cord injured rats.

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

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    Eva Meier Carlsen

    2014-06-01

    Full Text Available Spinal neuronal networks are essential for motor function. They are involved in the integration of sensory inputs and the generation of rhythmic motor outputs. They continuously adapt their activity to the internal state of the organism and to the environment. This plasticity can be provided 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. Neurons responded to electrical stimulation by monosynaptic EPSCs. 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 neighboring astrocyte increased the amplitude of synaptic currents. In contrast, when we selectively stimulated astrocytes by activating PAR-1 receptors with the peptide TFLLR, the amplitude of EPSCs evoked by a paired stimulation protocol was reduced. The paired-pulse ratio was increased, suggesting an inhibition occurring at the presynaptic side of synapses. In the presence of blockers for extracellular ectonucleotidases, TFLLR did not induce presynaptic inhibition. Puffing adenosine reproduced the effect of TFLLR and blocking adenosine A1 receptors with DPCPX prevented it. Altogether our results show that ventral horn astrocytes are responsible for a tonic and a phasic inhibition of excitatory synaptic transmission by releasing ATP, which gets converted into adenosine that binds to inhibitory

  1. 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.

  2. [Effect of spontaneous firing of injured dorsal root ganglion neuron on excitability of wide dynamic range neuron in rat spinal dorsal horn].

    Science.gov (United States)

    Song, Ying; Zhang, Yong-Mei; Xu, Jie; Wu, Jing-Ru; Qin, Xia; Hua, Rong

    2013-10-25

    The aim of the paper is to study the effect of spontaneous firing of injured dorsal root ganglion (DRG) neuron in chronic compression of DRG (CCD) model on excitability of wide dynamic range (WDR) neuron in rat spinal dorsal horn. In vivo intracellular recording was done in DRG neurons and in vivo extracellular recording was done in spinal WDR neurons. After CCD, incidence of spontaneous discharge and firing frequency enhanced to 59.46% and (4.30 ± 0.69) Hz respectively from 22.81% and (0.60 ± 0.08) Hz in normal control group (P neuron in CCD rats decreased the spontaneous activities of WDR neurons from (191.97 ± 45.20)/min to (92.50 ± 30.32)/min (P neuron evoked spontaneous firing in a reversible way (n = 5) in silent WDR neurons of normal rats. There was 36.36% (12/33) WDR neuron showing after-discharge in response to innocuous mechanical stimuli on cutaneous receptive field in CCD rats, while after-discharge was not seen in control rats. Local administration of TTX on DRG with a concentration of 50 nmol/L attenuated innocuous electric stimuli-evoked after-discharge of WDR neurons in CCD rats in a reversible manner, and the frequency was decreased from (263 ± 56.5) Hz to (117 ± 30) Hz (P neurons is influenced by spontaneous firings of DRG neurons after CCD.

  3. 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.

  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.

    Science.gov (United States)

    Duric, Vanja; McCarson, Kenneth E

    2007-10-31

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

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    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

  6. 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...

  7. Effects of ketamine on neuronal activity of the spinal dorsal horn in rats with unilateral hindpaw inflammation%氯胺酮对单足致炎大鼠脊髓背角神经元活动的影响

    Institute of Scientific and Technical Information of China (English)

    郭华; 李菁锦; 吕国蔚

    2000-01-01

    A total of 32 units were extracellularly recorded from the spinal dorsal horn of rats. Unitary discharges evoked by stimulation of A and C fiber in ipsilateral lateral and medial plantar nerve were increased after carrageenan injection to the plantar area. The evoked responses to both A and C fiber were significantly decreased or even disappeared after administration of ketamine. The windup phenomenon was observed in neurons located deeply in the dorsal horn following carrageenan injection and was significantly suppressed or abolished after ketamine administration. The results above show NMDA receptor appears to be involved in the increase of excitability and the development of windup phenomenon in the spinal cord dorsal horn associated with carrageenan induced inflammation.%在大鼠脊髓背角用细胞外记录技术共记录到32个单位.角叉菜胶一侧足底注射致炎后, 电刺激该侧足底内外侧神经激动其中A、C纤维时, 脊髓背角神经元的诱发放电数均显著增加; 静脉注射NMDA受体拮抗剂氯胺酮后, A、C纤维刺激诱发的放电反应均显著下降甚至消失. 致炎后脊髓背角深层单位出现Windup现象, 静脉注射氯胺酮后该现象减轻或消失.结果提示: 角叉菜胶致炎导致脊髓背角神经元兴奋性升高和Windup; NMDA受体参与炎症痛和Windup形成.

  8. Squamous cell carcinoma causing dorsal atlantoaxial spinal cord compression in a dog.

    Science.gov (United States)

    Miyazaki, Yuta; Aikawa, Takeshi; Nishimura, Masaaki; Iwata, Munetaka; Kagawa, Yumiko

    2016-10-01

    A 12-year-old Chihuahua dog was presented for cervical pain and progressive tetraparesis. Magnetic resonance imaging revealed spinal cord compression due to a mass in the dorsal atlantoaxial region. Surgical treatment was performed. The mass was histopathologically diagnosed as a squamous cell carcinoma. The dog recovered to normal neurologic status after surgery.

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

    Science.gov (United States)

    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.

  10. Altered responsiveness to substance P and 5-hydroxytryptamine in cat dorsal horn neurons after 5-HT depletion with p-chlorophenylalanine.

    Science.gov (United States)

    Jeftinija, S; Raspantini, C; Randić, M; Yaksh, T L; Go, V L; Larson, A A

    1986-03-12

    The responsiveness of functionally identified cat spinal dorsal horn neurons to iontophoretically applied substance P (SP) and 5-hydroxytryptamine (5-HT) has been investigated by means of extracellular recording after 5-HT depletion with p-chlorophenylalanine (p-CPA). In addition, the spinal levels of 5-HT, SP, cholecystokinin octapeptide, neurotensin, and vasoactive intestinal polypeptide have been measured in intact and p-CPA-pretreated cats. In the present study we have demonstrated an altered responsiveness of dorsal horn neurons to locally applied SP and 5-HT. We found in p-CPA-pretreated cats that the proportion of neurons responding with excitation to SP and 5-HT was significantly increased. At the same time, depression induced by 5-HT in the dorsal horn cells was virtually absent in p-CPA-pretreated animals. Our finding that spinal level of 5-HT was significantly decreased in p-CPA-treated animals is consistent with previous studies. No convincing alteration in the spinal levels of 4 analyzed peptides was found in p-CPA-treated animals. The present study has shown that pharmacological depletion of 5-HT has two major effects: (1) it increases significantly the proportion of dorsal horn neurons excited by SP and 5-HT; and (2) it is ineffective in inducing 5-HT supersensitivity. Further work is needed to explain mechanisms involved in these effects.

  11. Differentiation of idiopathic spinal cord herniation from dorsal arachnoid webs on MRI and CT myelography.

    Science.gov (United States)

    Schultz, Randall; Steven, Andrew; Wessell, Aaron; Fischbein, Nancy; Sansur, Charles A; Gandhi, Dheeraj; Ibrahimi, David; Raghavan, Prashant

    2017-03-24

    OBJECTIVE Dorsal arachnoid webs (DAWs) and spinal cord herniation (SCH) are uncommon abnormalities affecting the thoracic spinal cord that can result in syringomyelia and significant neurological morbidity if left untreated. Differentiating these 2 entities on the basis of clinical presentation and radiological findings remains challenging but is of vital importance in planning a surgical approach. The authors examined the differences between DAWs and idiopathic SCH on MRI and CT myelography to improve diagnostic confidence prior to surgery. METHODS Review of the picture archiving and communication system (PACS) database between 2005 and 2015 identified 6 patients with DAW and 5 with SCH. Clinical data including demographic information, presenting symptoms and neurological signs, and surgical reports were collected from the electronic medical records. Ten of the 11 patients underwent MRI. CT myelography was performed in 3 patients with DAW and in 1 patient with SCH. Imaging studies were analyzed by 2 board-certified neuroradiologists for the following features: 1) location of the deformity; 2) presence or absence of cord signal abnormality or syringomyelia; 3) visible arachnoid web; 4) presence of a dural defect; 5) nature of dorsal cord indentation (abrupt "scalpel sign" vs "C"-shaped); 6) focal ventral cord kink; 7) presence of the nuclear trail sign (endplate irregularity, sclerosis, and/or disc-space calcification that could suggest a migratory path of a herniated disc); and 8) visualization of a complete plane of CSF ventral to the deformity. RESULTS The scalpel sign was positive in all patients with DAW. The dorsal indentation was C-shaped in 5 of 6 patients with SCH. The ventral subarachnoid space was preserved in all patients with DAW and interrupted in cases of SCH. In no patient was a web or a dural defect identified. CONCLUSIONS DAW and SCH can be reliably distinguished on imaging by scrutinizing the nature of the dorsal indentation and the integrity of

  12. A afferent fibers are involved in the pathology of central changes in the spinal dorsal horn associated with myofascial trigger spots in rats.

    Science.gov (United States)

    Meng, Fei; Ge, Hong-You; Wang, Yong-Hui; Yue, Shou-Wei

    2015-11-01

    A afferent fibers have been reported to participate in the development of the central sensitization induced by inflammation and injuries. Current evidence suggests that myofascial trigger points (MTrPs) induce central sensitization in the related spinal dorsal horn, and clinical studies indicate that A fibers are associated with pain behavior. Because most of these clinical studies applied behavioral indexes, objective evidence is needed. Additionally, MTrP-related neurons in dorsal root ganglia and the spinal ventral horn have been reported to be smaller than normal, and these neurons were considered to be related to A fibers. To confirm the role of A fibers in MTrP-related central changes in the spinal dorsal horn, we studied central sensitization as well as the size of neurons associated with myofascial trigger spots (MTrSs, equivalent to MTrPs in humans) in the biceps femoris muscle of rats and provided some objective morphological evidence. Cholera toxin B subunit-conjugated horseradish peroxidase was applied to label the MTrS-related neurons, and tetrodotoxin was used to block A fibers specifically. The results showed that in the spinal dorsal horn associated with MTrS, the expression of glutamate receptor (mGluR1α/mGluR5/NMDAR1) increased, while the mean size of MTrS-related neurons was smaller than normal. After blocking A fibers, these changes reversed to some extent. Therefore, we concluded that A fibers participated in the development and maintenance of the central sensitization induced by MTrPs and were related to the mean size of neurons associated with MTrPs in the spinal dorsal horn.

  13. Effects of brain-derived neurotrophic factor on synapsin expression in rat spinal cord anterior horn neurons cultured in vitro

    Institute of Scientific and Technical Information of China (English)

    Zhifei Wang; Daguang Liao; Changqi Li

    2010-01-01

    Brain-derived neurotrophic factor(BDNF)promotes synaptic formation and functional maturation by upregulating synapsin expression in cortical and hippocampal neurons.However,it remains controversial whether BDNF affects synapsin expression in spinal cord anterior horn neurons.Wistar rat spinal cord anterior hom neurons were cultured in serum-supplemented medium containing BDNF,BDNF antibody,and Hank's solution for 3 days,and then synapsin I and synaptophysin protein and mRNA expression was detected.Under serum-supplemented conditions,the number of surviving neurons in the spinal cord anterior horn was similar among BDNF,anti-BDNF,and control groups(P > 0.05).Synapsin I and synaptophysin protein and mRNA expressions were increased in BDNF-treated neurons,but decreased in BDNF antibody-treated neurons(P< 0.01).These results indicated that BDNF significantly promotes synapsin I and synaptophysin expression in in vitro-cultured rat spinal cord anterior horn neurons.

  14. Peptidases prevent μ-opioid receptor internalization in dorsal horn neurons by endogenously released opioids

    OpenAIRE

    Song, Bingbing; Marvizón, Juan Carlos G.

    2003-01-01

    To evaluate the effect of peptidases on μ-opioid receptor (MOR) activation by endogenous opioids, we measured MOR-1 internalization in rat spinal cord slices. A mixture of inhibitors of aminopeptidases (amastatin), dipeptidyl carboxypeptidase (captopril), and neutral endopeptidase (phosphoramidon) dramatically increased the potencies of Leu-enkephalin and dynorphin A to produce MOR-1 internalization, and also enhanced the effects of Met-enkephalin and α-neoendorphin, but not endomorphins or β...

  15. Calcitonin gene-related peptide in anterior and posterior horns of spinal cord after brachial plexus injury

    Institute of Scientific and Technical Information of China (English)

    Longju Chen; Peijun Wang; Feng Li; Wutian Wu

    2007-01-01

    BACKGROUND: The changes of calcitonin gene-related peptide (CGRP) expression are closely associated with peripheral nerve injury, whereas it should be further investigated whether the damage of central nerve can lead to the changes of CGRP expression, and whether it is associated with the neural regeneration and repair.OBJECTIVE: To observe the changing law of CGRP expression in the anterior and posterior horns of spinal cord following brachial plexus injury.DESIGN: A randomized controlled trial.SETTINGS: Department of Anatomy, Yunyang Medical College; Department of Anatomy, Basic Medical College, Sun Yat-sen University.MATERIALS: Sixty-five adult male SD rats of clean degree, weighing 180 - 220 g, provided by the experimental animal center of the Basic Medical College, Sun Yat-sen University, were randomly divided into control group (n =5) and experimental group (n =60), and the latter was subdivided into three damage groups: avulsion of anterior root group (n =20), disjunction of posterior root group (n =20) and transection of spinal cord group (n =20). Diaminobenzidine (DAB) chromogen, rabbit anti-CGRP polyclonal antibody were the products of Sigma Company; Leica image analytical apparatus was produced by QUIN Company (Germany); Histotome by Sigma Company.METHODS: The experiments were carried out in the Department of Anatomy, Basic Medical College, Sun Yat-sen University from September 2004 to March 2005. Three kinds of models of brachial plexus injury were established: In the avulsion of anterior root group, right C7 anterior root was avulsed, and the distal nerve residual root was transected. In the disjunction of posterior root group, right C7 anterior root was avulsed and right C5 - T1 posterior horns were cut to block the sensory afferent pathway. In the transection of spinal cord group, right C7 anterior root was avulsed and C5-6 segments of right spinal cord were semi-transected to block the cortical descending pathway. In the control group, C5 - T1

  16. Developmental localization of calcitonin gene-related peptide in dorsal sensory axons and ventral motor neurons of mouse cervical spinal cord.

    Science.gov (United States)

    Kim, Jeongtae; Sunagawa, Masanobu; Kobayashi, Shiori; Shin, Taekyun; Takayama, Chitoshi

    2016-04-01

    Calcitonin gene-related peptide (CGRP) is a 37-amino-acid neuropeptide, synthesized by alternative splicing of calcitonin gene mRNA. CGRP is characteristically distributed in the nervous system, and its function varies depending on where it is expressed. To reveal developmental formation of the CGRP network and its function in neuronal maturation, we examined the immunohistochemical localization of CGRP in the developing mouse cervical spinal cord and dorsal root ganglion. CGRP immunolabeling (IL) was first detected in motor neurons on E13, and in ascending axons of the posterior funiculus and DRG neurons on E14. CGRP-positive sensory axon fibers entered Laminae I and II on E16, and Laminae I through IV on E18. The intensity of the CGRP-IL gradually increased in both ventral and dorsal horns during embryonic development, but markedly decreased in the ventral horn after birth. These results suggest that CGRP is expressed several days after neuronal settling and entry of sensory fibers, and that the CGRP network is formed in chronological and sequential order. Furthermore, because CGRP is markedly expressed in motor neurons when axons are vastly extending and innervating targets, CGRP may also be involved in axonal elongation and synapse formation during normal development.

  17. Physiological properties of enkephalin-containing neurons in the spinal dorsal horn visualized by expression of green fluorescent protein in BAC transgenic mice

    Directory of Open Access Journals (Sweden)

    Kofuji Takefumi

    2011-05-01

    Full Text Available Abstract Background Enkephalins are endogenous opiates that are assumed to modulate nociceptive information by mediating synaptic transmission in the central nervous system, including the spinal dorsal horn. Results To develop a new tool for the identification of in vitro enkephalinergic neurons and to analyze enkephalin promoter activity, we generated transgenic mice for a bacterial artificial chromosome (BAC. Enkephalinergic neurons from these mice expressed enhanced green fluorescent protein (eGFP under the control of the preproenkephalin (PPE gene (penk1 promoter. eGFP-positive neurons were distributed throughout the gray matter of the spinal cord, and were primarily observed in laminae I-II and V-VII, in a pattern similar to the distribution pattern of enkephalin-containing neurons. Double immunostaining analysis using anti-enkephalin and anti-eGFP antibodies showed that all eGFP-expressing neurons contained enkephalin. Incubation in the presence of forskolin, an activator of adenylate cyclase, increased the number of eGFP-positive neurons. These results indicate that eGFP expression is controlled by the penk1 promoter, which contains cyclic AMP-responsive elements. Sections obtained from sciatic nerve-ligated mice exhibited increased eGFP-positive neurons on the ipsilateral (nerve-ligated side compared with the contralateral (non-ligated side. These data indicate that PPE expression is affected by peripheral nerve injury. Additionally, single-neuron RT-PCR analysis showed that several eGFP positive-neurons in laminae I-II expressed glutamate decarboxylase 67 mRNA and that some expressed serotonin type 3 receptors. Conclusions These results suggest that eGFP-positive neurons in laminae I-II coexpress enkephalin and γ-aminobutyric acid (GABA, and are activated by forskolin and in conditions of nerve injury. The penk1-eGFP BAC transgenic mouse contributes to the further characterization of enkephalinergic neurons in the transmission and

  18. 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

    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 (Pcolon 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 that upregulation of TRPA1 expression in the SDH is associated with persistent post-inflammatory visceral hypersensitivity in the rat and provides insight into potential therapeutic targets for the control of persistent visceral hypersensitivity. PMID:27980434

  19. Dysregulation of Kv3.4 Channels in Dorsal Root Ganglia Following Spinal Cord Injury

    OpenAIRE

    Ritter, David M.; Zemel, Benjamin M.; Hala, Tamara J.; O'Leary, Michael E; Lepore, Angelo C.; Covarrubias, Manuel

    2015-01-01

    Spinal cord injury (SCI) patients develop chronic pain involving poorly understood central and peripheral mechanisms. Because dysregulation of the voltage-gated Kv3.4 channel has been implicated in the hyperexcitable state of dorsal root ganglion (DRG) neurons following direct injury of sensory nerves, we asked whether such a dysregulation also plays a role in SCI. Kv3.4 channels are expressed in DRG neurons, where they help regulate action potential (AP) repolarization in a manner that depen...

  20. Involvement of ATP in noxious stimulus-evoked release of glutamate in rat medullary dorsal horn: a microdialysis study.

    Science.gov (United States)

    Kumar, Naresh; Cherkas, Pavel S; Chiang, C Y; Dostrovsky, Jonathan O; Sessle, Barry J; Coderre, Terence J

    2012-12-01

    Our electrophysiological studies have shown that both purinergic and glutamatergic receptors are involved in central sensitization of nociceptive neurons in the medullary dorsal horn (MDH). Here we assessed the effects of intrathecal administration of apyrase (a nucleotide degrading enzyme of endogenous adenosine 5-triphosphate [ATP]), a combination of apyrase and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, an adenosine A1 receptor antagonist), or 2,3-O-2,4,6-trinitrophenyl-adenosine triphosphate (TNP-ATP, a P2X1, P2X3, P2X2/3 receptor antagonist) on the release of glutamate in the rat MDH evoked by application of mustard oil (MO) to the molar tooth pulp. In vivo microdialysis was used to dialyse the MDH every 5 min, and included 3 basal samples, 6 samples after drug treatment and 12 samples following application of MO. Tooth pulp application of MO induced a significant increase in glutamate release in the MDH. Superfusion of apyrase or TNP-ATP alone significantly reduced the MO-induced glutamate release in the MDH, as compared to vehicle. Furthermore, the suppressive effects of apyrase on glutamate release were reduced by combining it with DPCPX. This study demonstrates that application of an inflammatory irritant to the tooth pulp induces glutamate release in the rat MDH in vivo that may be reduced by processes involving endogenous ATP and adenosine. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Dorsal root potential produced by a TTX-insensitive micro-circuitry in the turtle spinal cord

    DEFF Research Database (Denmark)

    Russo, R E; Delgado-Lezama, R; Hounsgaard, J

    2000-01-01

    1, The mechanisms underlying the dorsal root potential (DRP) were studied in transverse slices of turtle spinal cord. DRPs were evoked by stimulating one filament in a dorsal root and were recorded from another such filament. 2. The DRP evoked at supramaximal stimulus intensity was reduced...

  2. Physiological properties of enkephalin-containing neurons in the spinal dorsal horn visualized by expression of green fluorescent protein in BAC transgenic mice

    OpenAIRE

    2011-01-01

    Abstract Background Enkephalins are endogenous opiates that are assumed to modulate nociceptive information by mediating synaptic transmission in the central nervous system, including the spinal dorsal horn. Results To develop a new tool for the identification of in vitro enkephalinergic neurons and to analyze enkephalin promoter activity, we generated transgenic mice for a bacterial artificial chromosome (BAC). Enkephalinergic neurons from these mice expressed enhanced green fluorescent prot...

  3. Spinal Cord Ventral Horns and Lymphoid Organ Involvement in Powassan Virus Infection in a Mouse Model

    Directory of Open Access Journals (Sweden)

    Rodrigo I. Santos

    2016-08-01

    Full Text Available Powassan virus (POWV belongs to the family Flaviviridae and is a member of the tick-borne encephalitis serogroup. Transmission of POWV from infected ticks to humans has been documented in the USA, Canada, and Russia, causing fatal encephalitis in 10% of human cases and significant neurological sequelae in survivors. We used C57BL/6 mice to investigate POWV infection and pathogenesis. After footpad inoculation, infected animals exhibited rapid disease progression and 100% mortality. Immunohistochemistry and immunofluorescence revealed a very strong neuronal tropism of POWV infection. The central nervous system infection appeared as a meningoencephalitis with perivascular mononuclear infiltration and microglial activation in the brain, and a poliomyelitis-like syndrome with high level of POWV antigen at the ventral horn of the spinal cord. Pathological studies also revealed substantial infection of splenic macrophages by POWV, which suggests that the spleen plays a more important role in pathogenesis than previously realized. This report provides a detailed description of the neuroanatomical distribution of the lesions produced by POWV infection in C57BL/6 mice.

  4. [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.

  5. SDF1 in the dorsal corticospinal tract promotes CXCR4+ cell migration after spinal cord injury

    Directory of Open Access Journals (Sweden)

    Jung Hosung

    2011-02-01

    Full Text Available Abstract Background Stromal cell-derived factor-1 (SDF1 and its major signaling receptor, CXCR4, were initially described in the immune system; however, they are also expressed in the nervous system, including the spinal cord. After spinal cord injury, the blood brain barrier is compromised, opening the way for chemokine signaling between these two systems. These experiments clarified prior contradictory findings on normal expression of SDF1 and CXCR4 as well as examined the resulting spinal cord responses resulting from this signaling. Methods These experiments examined the expression and function of SDF1 and CXCR4 in the normal and injured adult mouse spinal cord primarily using CXCR4-EGFP and SDF1-EGFP transgenic reporter mice. Results In the uninjured spinal cord, SDF1 was expressed in the dorsal corticospinal tract (dCST as well as the meninges, whereas CXCR4 was found only in ependymal cells surrounding the central canal. After spinal cord injury (SCI, the pattern of SDF1 expression did not change rostral to the lesion but it disappeared from the degenerating dCST caudally. By contrast, CXCR4 expression changed dramatically after SCI. In addition to the CXCR4+ cells in the ependymal layer, numerous CXCR4+ cells appeared in the peripheral white matter and in the dorsal white matter localized between the dorsal corticospinal tract and the gray matter rostral to the lesion site. The non-ependymal CXCR4+ cells were found to be NG2+ and CD11b+ macrophages that presumably infiltrated through the broken blood-brain barrier. One population of macrophages appeared to be migrating towards the dCST that contains SDF1 rostral to the injury but not towards the caudal dCST in which SDF1 is no longer present. A second population of the CXCR4+ macrophages was present near the SDF1-expressing meningeal cells. Conclusions These observations suggest that attraction of CXCR4+ macrophages is part of a programmed response to injury and that modulation of the

  6. Multiple neural tube defects: a rare combination of limited dorsal myeloschisis, diplomyelia with dorsal bony spur, sacral meningocoele, syringohydromyelia, and tethered cord.

    Science.gov (United States)

    Shashank R, Ramdurg; Shubhi, Dubey; Vishal, Kadeli

    2017-04-01

    Multiple neural tube defects are relatively rare. They account for less than 1% reported neural tube defects. Cases of limited dorsal myeloschisis (LDM) and diplomyelia (two cords in single sac without intervening bony or fibrous septae) with dorsal bony spur are also a rare event. Here, the authors report a rare case of neonate with thoracic LDM, diplomyelia with dorsal bony spur, sacral meningocoele with syringohydromyelia, and low-lying tethered cord. The child also had a ventricular septal defect (VSD) and bilateral rocker bottom feet. Various environmental factors and genetic mutations in transmembrane proteins have been studied in animal models explaining the origin of neural tube defects. To the best of author's knowledge, this is the first case of varied multiple neural tube defects with diplomyelia reported in world literature.

  7. Recurrent dorsal root potentials and motoneuron morphology in the frog spinal cord.

    Science.gov (United States)

    Shupliakov, O V; Antal, M; Székely, G

    1990-09-18

    About one third of motoneurons stimulated intracellularly evoked dorsal root potentials (DRP) in the lumbar segments of the isolated and perfused frog spinal cord. Axon collaterals were found in one of the 22 motoneurons filled with HRP (horseradish peroxidase) through the stimulating electrode. In further experiments injecting individual motoneurons with cobalt, and filling the ventral roots with HRP or cobalt, the frequency of occurrence of axon collaterals was about 2% of the number of labelled motor cells. It is suggested that the presence of motor axon collaterals is not indispensable in the generation of the DRP evoked by ventral root or motor cell stimulation.

  8. A Combinatorial Approach to Induce Sensory Axon Regeneration into the Dorsal Root Avulsed Spinal Cord

    DEFF Research Database (Denmark)

    Hoeber, Jan; Konig, Niclas; Trolle, Carl

    2017-01-01

    restores sensory functions. In this study, we elucidate mechanisms underlying stem cell-mediated ingrowth of sensory axons after dorsal root avulsion (DRA). We show that human spinal cord neural stem/progenitor cells (hscNSPC), and also, mesoporous silica particles loaded with growth factor mimetics (MesoMIM......), supported sensory axon regeneration. However, when hscNSPC and MesoMIM were combined, sensory axon regeneration failed. Morphological and tracing analysis showed that sensory axons grow through the newly established glial scar along “bridges” formed by migrating stem cells. Coimplantation of MesoMIM...... prevented stem cell migration, “bridges” were not formed, and sensory axons failed to enter the spinal cord. MesoMIM applied alone supported sensory axons ingrowth, but without affecting glial scar formation. In vitro, the presence of MesoMIM significantly impaired migration of hscNSPC without affecting...

  9. Baicalin ameliorates neuropathic pain by suppressing HDAC1 expression in the spinal cord of spinal nerve ligation rats

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    Chen-Hwan Cherng

    2014-08-01

    Conclusion: The present findings suggest that baicalin can ameliorate neuropathic pain by suppressing HDAC1 expression and preventing histone-H3 acetylation in the spinal cord dorsal horn of SNL rats.

  10. Brainstem neurons with descending projections to the spinal cord of two elasmobranch fishes: thornback guitarfish, Platyrhinoidis triseriata, and horn shark, Heterodontus francisci.

    Science.gov (United States)

    Cruce, W L; Stuesse, S L; Northcutt, R G

    1999-01-25

    We studied two cartilaginous fishes and described their brainstem supraspinal projections because most nuclei in the reticular formation can be identified that way. A retrogradely transported tracer, horseradish peroxidase or Fluoro-Gold, was injected into the spinal cord of Platyrhinoidis triseriata (thornback guitarfish) or Heterodontus fransisci (horn shark). We described labeled reticular cells by their position, morpohology, somatic orientation, dendritic processes, and laterality of spinal projections. Nineteen reticular nuclei have spinal projections: reticularis (r.) dorsalis, r. ventralis pars alpha and beta, r. gigantocellularis, r. magnocellularis, r. parvocellularis, r. paragigantocellularis lateralis and dorsalis, r. pontis caudalis pars alpha and beta, r. pontis oralis pars medialis and lateralis, r. subcuneiformis, r. peduncularis pars compacta, r. subcoeruleus pars alpha, raphe obscurus, raphe pallidus, raphe magnus, and locus coeruleus. Twenty nonreticular nuclei have spinal projections: descending trigeminal, retroambiguus, solitarius, posterior octaval, descending octaval, magnocellular octaval, ruber, Edinger-Westphal, nucleus of the medial longitudinal fasciculus, interstitial nucleus of Cajal, latral mesencephalic complex, periventricularis pretectalis pars dorsalis, central pretectal, ventromedial thalamic, posterior central thalamic, posterior dorsal thalamic, the posterior tuberculum, and nuclei B, F, and J. The large number of distinct reticular nuclei with spinal projections corroborates the hypothesis that the reticular formation of elasmobranches is complexly organized into many of the same nuclei that are found in frogs, reptiles, birds, and mammals.

  11. Chemokine CCL2 and its receptor CCR2 in the medullary dorsal horn are involved in trigeminal neuropathic pain

    Directory of Open Access Journals (Sweden)

    Zhang Zhi-Jun

    2012-07-01

    Full Text Available Abstract Background Neuropathic pain in the trigeminal system is frequently observed in clinic, but the mechanisms involved are largely unknown. In addition, the function of immune cells and related chemicals in the mechanism of pain has been recognized, whereas few studies have addressed the potential role of chemokines in the trigeminal system in chronic pain. The present study was undertaken to test the hypothesis that chemokine C-C motif ligand 2 (CCL2-chemokine C-C motif receptor 2 (CCR2 signaling in the trigeminal nucleus is involved in the maintenance of trigeminal neuropathic pain. Methods The inferior alveolar nerve and mental nerve transection (IAMNT was used to induce trigeminal neuropathic pain. The expression of ATF3, CCL2, glial fibrillary acidic protein (GFAP, and CCR2 were detected by immunofluorescence histochemical staining and western blot. The cellular localization of CCL2 and CCR2 were examined by immunofluorescence double staining. The effect of a selective CCR2 antagonist, RS504393 on pain hypersensitivity was checked by behavioral testing. Results IAMNT induced persistent (>21 days heat hyperalgesia of the orofacial region and ATF3 expression in the mandibular division of the trigeminal ganglion. Meanwhile, CCL2 expression was increased in the medullary dorsal horn (MDH from 3 days to 21 days after IAMNT. The induced CCL2 was colocalized with astroglial marker GFAP, but not with neuronal marker NeuN or microglial marker OX-42. Astrocytes activation was also found in the MDH and it started at 3 days, peaked at 10 days and maintained at 21 days after IAMNT. In addition, CCR2 was upregulated by IAMNT in the ipsilateral medulla and lasted for more than 21 days. CCR2 was mainly colocalized with NeuN and few cells were colocalized with GFAP. Finally, intracisternal injection of CCR2 antagonist, RS504393 (1, 10 μg significantly attenuated IAMNT-induced heat hyperalgesia. Conclusion The data suggest that CCL2-CCR

  12. Effects of tyrosyl-arginine (kyotorphin), a new opioid dipeptide, on single neurons in the spinal dorsal horn of rabbits and the nucleus reticularis paragigantocellularis of rats.

    Science.gov (United States)

    Satoh, M; Kawajiri, S; Yamamoto, M; Akaike, A; Ukai, Y; Takagi, H

    1980-03-01

    The effects of a new endogenous opioid dipeptide (Tyr-Arg), kyotorphin, on single unit activities recorded from the lamina V type neurons in the spinal dorsal horn and the neurons in nucleus reticularis paragigantocellularis (NRPG) of the medulla oblongata were investigated in the rabbit and rat, respectively. Microelectrophoretically applied kyotorphin predominantly depressed the lamina V type neurons but excited the NRPG neurons. Such predominant effects were antagonized by naloxone. These results suggest that kyotorphin has qualitatively similar actions to those of enkephalins in both central regions examined.

  13. P2Y1 purinoceptor inhibition reduces extracellular signal-regulated protein kinase 1/2 phosphorylation in spinal cord and dorsal root ganglia: implications for cancer-induced bone pain

    Institute of Scientific and Technical Information of China (English)

    Jun Chen; Lina Wang; Yanbing Zhang; Jianping Yang

    2012-01-01

    It remains unclear as to whether P2Y1 purinergic receptor (P2Y1R) and the molecules that act downstream,such as extracellular signal-regulated protein kinase 1/2 (ERK1/2),are involved in the development of cancer-induced bone pain (CIBP) in vivo.Here,we investigated the role of the P2Y1R in the modulation of CIBP-associated nociception in spinal cord and dorsal root ganglia (DRG).A CIBP model was established by inoculating Walker 256 gland carcinoma cells into the tibia of female rats.Tactile ailodynia and spontaneous pain were assessed using von Frey filaments and ambulatory scores.The results showed that both the paw withdrawal latency to tactile allodynia and the ambulatory score to spontaneous pain were significantly different between the CIBP group and the sham group on days 7-9 post-inoculation (P < 0.01).Furthermore,rats in the CIBP group also showed a progressive increase in ambulatory score,which is different from the sham group (P<0.01).Furthermore,P2Y1R mRNA and phosphory lated ERK1/2 (p-ERK1/2) protein expression levels were increased in the spinal dorsal horn and DRG of the CIBP group relative to the sham group.However,intrathecal injection of the P2Y1R antagonist MRS2179 decreased P2Y1R mRNA and p-ERK1/2 protein expression in the spinal dorsal horn and DRG (P<0.01).These results provide evidence that the inhibition of P2Y1R-mediated ERK1/2 phosphorylation in the spinal dorsal horn and DRG can attenuate nociception transmission.

  14. Spinal Autofluorescent Flavoprotein Imaging in a Rat Model of Nerve Injury-Induced Pain and the Effect of Spinal Cord Stimulation

    NARCIS (Netherlands)

    J.L.M. Jongen (Joost); H. Smits (Helwin); T. Pederzani (Tiziana); M. Bechakra (Malik); S.M. Hossaini (Mehdi); S.K.E. Koekkoek (Bas); F.J.P.M. Huygen; C.I. de Zeeuw (Chris); J.C. Holstege (Jan C.); E.A.J. Joosten (Elbert A.J.)

    2014-01-01

    textabstractNerve injury may cause neuropathic pain, which involves hyperexcitability of spinal dorsal horn neurons. The mechanisms of action of spinal cord stimulation (SCS), an established treatment for intractable neuropathic pain, are only partially understood. We used Autofluorescent Flavoprote

  15. Spinal autofluorescent flavoprotein imaging in a rat model of nerve injury-induced pain and the effect of spinal cord stimulation

    NARCIS (Netherlands)

    Jongen, Joost L M; Smits, Helwin; Pederzani, Tiziana; Bechakra, Malik; Hossaini, Mehdi; Koekkoek, Sebastiaan K; Huygen, Frank J P M; De Zeeuw, Chris I; Holstege, Jan C; Joosten, Elbert A J

    2014-01-01

    Nerve injury may cause neuropathic pain, which involves hyperexcitability of spinal dorsal horn neurons. The mechanisms of action of spinal cord stimulation (SCS), an established treatment for intractable neuropathic pain, are only partially understood. We used Autofluorescent Flavoprotein Imaging (

  16. Spinal autofluorescent flavoprotein imaging in a rat model of nerve injury-induced pain and the effect of spinal cord stimulation

    NARCIS (Netherlands)

    Jongen, Joost L M; Smits, Helwin; Pederzani, Tiziana; Bechakra, Malik; Hossaini, Mehdi; Koekkoek, Sebastiaan K; Huygen, Frank J P M; De Zeeuw, Chris I; Holstege, Jan C; Joosten, Elbert A J

    2014-01-01

    Nerve injury may cause neuropathic pain, which involves hyperexcitability of spinal dorsal horn neurons. The mechanisms of action of spinal cord stimulation (SCS), an established treatment for intractable neuropathic pain, are only partially understood. We used Autofluorescent Flavoprotein Imaging

  17. Spinal Autofluorescent Flavoprotein Imaging in a Rat Model of Nerve Injury-Induced Pain and the Effect of Spinal Cord Stimulation

    NARCIS (Netherlands)

    J.L.M. Jongen (Joost); H. Smits (Helwin); T. Pederzani (Tiziana); M. Bechakra (Malik); S.M. Hossaini (Mehdi); S.K.E. Koekkoek (Bas); F.J.P.M. Huygen; C.I. de Zeeuw (Chris); J.C. Holstege (Jan C.); E.A.J. Joosten (Elbert A.J.)

    2014-01-01

    textabstractNerve injury may cause neuropathic pain, which involves hyperexcitability of spinal dorsal horn neurons. The mechanisms of action of spinal cord stimulation (SCS), an established treatment for intractable neuropathic pain, are only partially understood. We used Autofluorescent

  18. N-methyl-D-aspartate receptor expression in the spinal dorsal horn of a rat model of formalin-induced inflammatory pain following intrathecal injection of butorphanol

    Institute of Scientific and Technical Information of China (English)

    Yichun Wang; Yuan Zhang; Qulian Guo; Xiaohong Liu; Mingde Wang; Hui Luo

    2010-01-01

    Clinical and animal experiments have proved that intrathecal injection of butorphanol has an analgesic effect. However, whether the analgesic effect is associated with activation of the N-methyl-D-aspartate (NMDA) receptor remains unclear. This study presumed that intrathecal injection of butorphanol has an analgesic effect on formalin-induced inflammatory pain in rats, and its analgesic effect is associated with inhibition of NMDA receptors. Concurrently, ketamine was injected into the intrathecal space, which is a non-competitive NMDA receptor antagonist, to determine the analgesic mechanism of butorphanol. The total reflection time in phase 1 and phase 2 of rat hind paws carding action was reduced when the butorphanol dose was increased to 25 μg,or a low dose of butorphanol was combined with ketamine. Intrathecal injection of a high dose of butorphanol alone or a Iow dose of butorphanol combined with ketamine can remarkably reduce NMDA receptor expression in the L5 spinal dorsal horn of formalin-induced pain rats. The results suggest that intrathecal injection of butorphanol has analgesic effects on formalin-induced inflammatory pain, and remarkably reduces NMDA receptor expression in the rat spinal dorsal horn.Ketamine strengthens this analgesic effect. The analgesic mechanism of intrathecal injection of butorphanol is associated with inhibition of NMDA receptor activation.

  19. Chemokine CCL2 up-regulated in the medullary dorsal horn astrocytes contributes to nocifensive behaviors induced by experimental tooth movement.

    Science.gov (United States)

    Luo, Wei; Fu, Runqing; Tan, Yu; Fang, Bing; Yang, Zhi

    2014-02-01

    To test the hypothesis that the astrocytic chemokine (C-C motif) ligand 2 (CCL2) plays an important role in nocifensive behaviors after experimental tooth movement (ETM), the expression and cellular localization of CCL2 and astrocyte activation in the medullary dorsal horn (MDH) were determined by immunohistochemistry in rats. The dose-dependent effects of intrathecal C-C chemokine receptor type 2 (CCR2) antagonists on these changes in nocifensive behaviors were evaluated. Exogenous CCL2 was added to medullary dorsal horn slices to evaluate its contributory role in the induction of extracellular signal-regulated kinase (ERK) activation ex vivo. We found a significant increase in the expression of CCL2 and glial fibrillary acidic protein (GFAP), corresponding well to the nocifensive behaviors after ETM. In addition, application of recombinant CCL2 led to ERK activation, which could be attenuated effectively by pretreatment with CCL2-neutralizing antibody ex vivo. The magnitude of the nocifensive behavior could be reduced by medullary CCR2 antagonists in a dose-dependent manner. Therefore, the astrocytic CCL2 is actively involved in the development and maintenance of tooth-movement pain and thus may be a potential target for analgesics in orthodontic nocifensive responses control.

  20. In vivo longitudinal Myelin Water Imaging in rat spinal cord following dorsal column transection injury.

    Science.gov (United States)

    Kozlowski, Piotr; Rosicka, Paulina; Liu, Jie; Yung, Andrew C; Tetzlaff, Wolfram

    2014-04-01

    Longitudinal Myelin Water Imaging was carried out in vivo to characterize white matter damage following dorsal column transection (DC Tx) injury at the lumbar level L1 of rat spinal cords. A transmit-receive implantable coil system was used to acquire multiple spin-echo (MSE) quantitative T2 data from the lumbar spinal cords of 16 rats at one week pre-injury as well as 3 and 8weeks post-injury (117 microns in-plane resolution and 1.5mm slice thickness). In addition, ex vivo MSE and DTI data were acquired from cords fixed and excised at 3 or 8weeks post injury using a solenoid coil. The MSE data were used to generate Myelin Water Fractions (MWFs) as a surrogate measure of myelin content, while DTI data were acquired to study damage to the axons. Myelin damage was assessed histologically with Eriochrome cyanine (EC) and Myelin Basic Protein in degenerated myelin (dgen-MBP) staining, and axonal damage was assessed by neurofilament-H in combination with neuron specific beta-III-tubulin (NF/Tub) staining. These MRI and histological measures of injury were studied in the dorsal column at 5mm cranial and 5mm caudal to injury epicenter. MWF increased significantly at 3weeks post-injury at both the cranial and caudal sites, relative to baseline. The values on the cranial side of injury returned to baseline at 8weeks post-injury but remained elevated on the caudal side. This trend was found in both in vivo and ex vivo data. This MWF increase was likely due to the presence of myelin debris, which were cleared by 8 weeks on the cranial, but not the caudal, side. Both EC and dgen-MBP stains displayed similar trends. MWF showed significant correlation with EC staining (R=0.63, p=0.005 in vivo and R=0.74, p=0.0001 ex vivo). MWF also correlated strongly with the dgen-MBP stain, but only on the cranial side (R=0.64, p=0.05 in vivo; R=0.63, p=0.038 ex vivo). This study demonstrates that longitudinal MWI in vivo can accurately characterize white matter damage in DC Tx model of injury

  1. Resolvin D1 reverses chronic pancreatitis-induced mechanical allodynia, phosphorylation of NMDA receptors, and cytokines expression in the thoracic spinal dorsal horn

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    Quan-Xin Feng

    2012-10-01

    Full Text Available Abstract Background We previously reported that immune activation in the spinal dorsal horn contributes to pain induced by chronic pancreatitis (CP. Targeting immune response in the CNS may provide effective treatments for CP-induced pain. Recent findings demonstrate that resolvin D1 (RvD1 can potently dampen inflammatory pain. We hypothesized that intrathecal injection of RvD1 may inhibit pain of CP. Methods Rat CP model was built through intrapancreatic infusion of trinitrobenzene sulfonic acid (TNBS. All the rats were divided into three groups: TNBS, sham, and naïve controls and were further divided for intrathecal RvD1 administration. Pain behavior of rats was tested with von Frey filaments. Anxiety-like behavior and free locomotor and exploration of rats were evaluated by open field test and elevated plus maze. Pancreatic histology was evaluated with hematoxylin and eosin staining. Phosphorylation of NMDA receptor and expression of inflammatory cytokines were examined with Western blot, real-time RT-PCR and ELISA. Results Behavioral study indicated that compared to the vehicle control, RvD1 (100 ng/kg significantly decreased TNBS-induced mechanical allodynia at 2 h after administration (response frequencies: 49.2 ± 3.7% vs 71.3 ± 6.1%, and this effect was dose-dependent. Neither CP nor RvD1 treatment could affect anxiety-like behavior. CP or RvD1 treatment could not affect free locomotor and exploration of rats. Western blot analysis showed that compared with that of naïve group, phosphorylated NR1 (pNR1 and pNR2B in TNBS rats were significantly increased in the spinal cord (pNR1: 3.87±0.31 folds of naïve control, pNR2B: 4.17 ± 0.24 folds of naïve control. Compared to vehicle control, 10 ng/kg of RvD1 could significantly block expressions of pNR1 (2.21 ± 0.26 folds of naïve and pNR2B (3.31 ± 0.34 folds of naïve. Real-time RT-PCR and ELISA data showed that RvD1 (10 ng/kg but not vehicle could significantly block expressions of

  2. Electron Microscopic Investigation of Monoaminergic Terminals to α-Motoneurons in the Anterior Horn of the Cat Spinal Cord

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    Mizukawa,Kiminao

    1982-04-01

    Full Text Available In the anterior horn of the cat thoracic cord, networks of the monoaminergic fibers surrounding the alpha-motoneurons were investigated by fluorescent microscopy and submicroscopically. Monoaminergic terminals were recognized by the administration of 5-OHDA electron microscopically. These terminals could be classified morphologically into three types. The physiological significance of monoaminergic control of alpha-motoneurons was discussed. Type I of the labeled terminals did not show any typical synaptic specialization, such as aggregation of synaptic vesicles or thickening of the pre- and postsynaptic membranes. This type did not have synaptic contact with the alpha-motoneurons. Type II showed typical synaptic contact and asymmetrical synaptic type membranous thickening. A large number of small dense-cored vesicles were accumulated in the vicinity of the presynaptic membranes. Type III contained a large number of small and large dense-cored vesicles and a few flattened small vesicles. This type had synaptic contact with the presynaptic nerve ending in which a large number of agranular vesicles were contained. This study demonstrated that alpha-motoneurons in the anterior horn receive supraspinal monoaminergic control in three ways: modulator control through Type I, monosynaptic direct control through Type II, and inhibitory control through Type III.

  3. Enhanced pre-synaptic glutamate release in deep-dorsal horn contributes to calcium channel alpha-2-delta-1 protein-mediated spinal sensitization and behavioral hypersensitivity

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    Dickenson Anthony H

    2009-02-01

    Full Text Available Abstract Nerve injury-induced expression of the spinal calcium channel alpha-2-delta-1 subunit (Cavα2δ1 has been shown to mediate behavioral hypersensitivity through a yet identified mechanism. We examined if this neuroplasticity modulates behavioral hypersensitivity by regulating spinal glutamatergic neurotransmission in injury-free transgenic mice overexpressing the Cavα2δ1 proteins in neuronal tissues. The transgenic mice exhibited hypersensitivity to mechanical stimulation (allodynia similar to the spinal nerve ligation injury model. Intrathecally delivered antagonists for N-methyl-D-aspartate (NMDA and α-amino-3-hydroxyl-5-methylisoxazole-4-propionic acid (AMPA/kainate receptors, but not for the metabotropic glutamate receptors, caused a dose-dependent allodynia reversal in the transgenic mice without changing the behavioral sensitivity in wild-type mice. This suggests that elevated spinal Cavα2δ1 mediates allodynia through a pathway involving activation of selective glutamate receptors. To determine if this is mediated by enhanced spinal neuronal excitability or pre-synaptic glutamate release in deep-dorsal horn, we examined wide-dynamic-range (WDR neuron excitability with extracellular recording and glutamate-mediated excitatory postsynaptic currents with whole-cell patch recording in deep-dorsal horn of the Cavα2δ1 transgenic mice. Our data indicated that overexpression of Cavα2δ1 in neuronal tissues led to increased frequency, but not amplitude, of miniature excitatory post synaptic currents mediated mainly by AMPA/kainate receptors at physiological membrane potentials, and also by NMDA receptors upon depolarization, without changing the excitability of WDR neurons to high intensity stimulation. Together, these findings support a mechanism of Cavα2δ1-mediated spinal sensitization in which elevated Cavα2δ1 causes increased pre-synaptic glutamate release that leads to reduced excitation thresholds of post-synaptic dorsal

  4. Endogenous interleukin-1β in neuropathic rats enhances glutamate release from the primary afferents in the spinal dorsal horn through coupling with presynaptic N-methyl-D-aspartic acid receptors.

    Science.gov (United States)

    Yan, Xisheng; Weng, Han-Rong

    2013-10-18

    Excessive activation of glutamate receptors and overproduction of proinflammatory cytokines, including interleukin-1β (IL-1β) in the spinal dorsal horn, are key mechanisms underlying the development and maintenance of neuropathic pain. In this study, we investigated the mechanisms by which endogenous IL-1β alters glutamatergic synaptic transmission in the spinal dorsal horn in rats with neuropathic pain induced by ligation of the L5 spinal nerve. We demonstrated that endogenous IL-1β in neuropathic rats enhances glutamate release from the primary afferent terminals and non-NMDA glutamate receptor activities in postsynaptic neurons in the spinal dorsal horn. Myeloid differentiation primary response protein 88 (MyD88) is a mediator used by IL-1β to enhance non-NMDA glutamate receptor activities in postsynaptic neurons in the spinal dorsal horn. Presynaptic NMDA receptors are effector receptors used by the endogenous IL-1β to enhance glutamate release from the primary afferents in neuropathic rats. This is further supported by the fact that NMDA currents recorded from small neurons in the dorsal root ganglion of normal rats are potentiated by exogenous IL-1β. Furthermore, we provided evidence that functional coupling between IL-1β receptors and presynaptic NMDA receptors at the primary afferent terminals is mediated by the neutral sphingomyelinase/ceramide signaling pathway. Hence, functional coupling between IL-1β receptors and presynaptic NMDA receptors at the primary afferent terminals is a crucial mechanism leading to enhanced glutamate release and activation of non-NMDA receptors in the spinal dorsal horn neurons in neuropathic pain conditions. Interruption of such functional coupling could be an effective approach for the treatment of neuropathic pain.

  5. A combined electrophysiological and morphological study of neuropeptide Y-expressing inhibitory interneurons in the spinal dorsal horn of the mouse.

    Science.gov (United States)

    Iwagaki, Noboru; Ganley, Robert P; Dickie, Allen C; Polgár, Erika; Hughes, David I; Del Rio, Patricia; Revina, Yulia; Watanabe, Masahiko; Todd, Andrew J; Riddell, John S

    2016-03-01

    The spinal dorsal horn contains numerous inhibitory interneurons that control transmission of somatosensory information. Although these cells have important roles in modulating pain, we still have limited information about how they are incorporated into neuronal circuits, and this is partly due to difficulty in assigning them to functional populations. Around 15% of inhibitory interneurons in laminae I-III express neuropeptide Y (NPY), but little is known about this population. We therefore used a combined electrophysiological/morphological approach to investigate these cells in mice that express green fluorescent protein (GFP) under control of the NPY promoter. We show that GFP is largely restricted to NPY-immunoreactive cells, although it is only expressed by a third of those in lamina I-II. Reconstructions of recorded neurons revealed that they were morphologically heterogeneous, but never islet cells. Many NPY-GFP cells (including cells in lamina III) appeared to be innervated by C fibres that lack transient receptor potential vanilloid-1, and consistent with this, we found that some lamina III NPY-immunoreactive cells were activated by mechanical noxious stimuli. Projection neurons in lamina III are densely innervated by NPY-containing axons. Our results suggest that this input originates from a small subset of NPY-expressing interneurons, with the projection cells representing only a minority of their output. Taken together with results of previous studies, our findings indicate that somatodendritic morphology is of limited value in classifying functional populations among inhibitory interneurons in the dorsal horn. Because many NPY-expressing cells respond to noxious stimuli, these are likely to have a role in attenuating pain and limiting its spread.

  6. Protein kinase C gamma interneurons in the rat medullary dorsal horn: distribution and synaptic inputs to these neurons, and subcellular localization of the enzyme.

    Science.gov (United States)

    Peirs, Cédric; Patil, Sudarshan; Bouali-Benazzouz, Rabia; Artola, Alain; Landry, Marc; Dallel, Radhouane

    2014-02-01

    The γ isoform of protein kinase C (PKCγ), which is concentrated in interneurons in the inner part of lamina II (IIi ) of the dorsal horn, has been implicated in the expression of tactile allodynia. Lamina IIi PKCγ interneurons were shown to be activated by tactile inputs and to participate in local circuits through which these inputs can reach lamina I, nociceptive output neurons. That such local circuits are gated by glycinergic inhibition and that A- and C-fibers low threshold mechanoreceptors (LTMRs) terminate in lamina IIi raise the general issue of synaptic inputs to lamina IIi PKCγ interneurons. Combining light and electron microscopic immunochemistry in the rat spinal trigeminal nucleus, we show that PKCγ-immunoreactivity is mostly restricted to interneurons in lamina IIi of the medullary dorsal horn, where they constitute 1/3 of total neurons. The majority of synapses on PKCγ-immunoreactive interneurons are asymmetric (likely excitatory). PKCγ-immunoreactive interneurons appear to receive exclusively myelinated primary afferents in type II synaptic glomeruli. Neither large dense core vesicle terminals nor type I synaptic glomeruli, assumed to be the endings of unmyelinated nociceptive terminals, were found on these interneurons. Moreover, there is no vesicular glutamate transporter 3-immunoreactive bouton, specific to C-LTMRs, on PKCγ-immunoreactive interneurons. PKCγ-immunoreactive interneurons contain GABAA ergic and glycinergic receptors. At the subcellular level, PKCγ-immunoreactivity is mostly concentrated on plasma membranes, close to, but not within, postsynaptic densities. That only myelinated primary afferents were found to contact PKCγ-immunoreactive interneurons suggests that myelinated, but not unmyelinated, LTMRs play a critical role in the expression of mechanical allodynia.

  7. Activation of medullary dorsal horn γ isoform of protein kinase C interneurons is essential to the development of both static and dynamic facial mechanical allodynia.

    Science.gov (United States)

    Pham-Dang, Nathalie; Descheemaeker, Amélie; Dallel, Radhouane; Artola, Alain

    2016-03-01

    The γ isoform of protein kinase C (PKCγ), which is concentrated in a specific class of interneurons within inner lamina II (IIi ) of the spinal dorsal horn and medullary dorsal horn (MDH), is known to be involved in the development of mechanical allodynia, a widespread and intractable symptom of inflammatory or neuropathic pain. However, although genetic and pharmacological impairment of PKCγ were shown to prevent mechanical allodynia in animal models of pain, after nerve injury or reduced inhibition, the functional consequences of PKCγ activation alone on mechanical sensitivity are still unknown. Using behavioural and anatomical approaches in the rat MDH, we tested whether PKCγ activation in naive animals is sufficient for the establishment of mechanical allodynia. Intracisternal injection of the phorbol ester, 12,13-dibutyrate concomitantly induced static as well as dynamic facial mechanical allodynia. Monitoring neuronal activity within the MDH with phospho-extracellular signal-regulated kinases 1 and 2 immunoreactivity revealed that activation of both lamina I-outer lamina II and IIi -outer lamina III neurons, including lamina IIi PKCγ-expressing interneurons, was associated with the manifestation of mechanical allodynia. Phorbol ester, 12,13-dibutyrate-induced mechanical allodynia and associated neuronal activations were all prevented by inhibiting selectively segmental PKCγ with KIG31-1. Our findings suggest that PKCγ activation, without any other experimental manipulation, is sufficient for the development of static and dynamic mechanical allodynia. Lamina IIi PKCγ interneurons have been shown to be directly activated by low-threshold mechanical inputs carried by myelinated afferents. Thus, the level of PKCγ activation within PKCγ interneurons might gate the transmission of innocuous mechanical inputs to lamina I, nociceptive output neurons, thus turning touch into pain.

  8. Material basis for inhibition of Dragon's Blood on evoked discharges of wide dynamic range neurons in spinal dorsal horn of rats

    Institute of Scientific and Technical Information of China (English)

    GUO Min; CHEN Su; LIU XiangMing

    2008-01-01

    In vivo experiments were designed to verify the analgesic effect of Dragon's Blood and the material basis for this effect. Extracellular microelectrode recordings were used to observe the effects of Dragon's Blood and various combinations of the three components (cochinchinenin A, cochinchinenin B, and Ioureirin B) extracted from Dragon's Blood on the discharge activities of wide dynamic range (WDR) neurons in spinal dorsal horn (SDH) of intact male Wistar rats evoked by electric stimulation at sciatic nerve. When the Hill's coefficients describing the dose-response relations of drugs were dif-ferent, based on the concept of dose equivalence, the equations of addillvity surfaces which can be applied to assess the interaction between three drugs were derived. Adopting the equations and Tal-larida's isobole equations used to assess the interaction between two drugs with dissimilar dose-response relations, the effects produced by various combinations of the three components in modulating the evoked discharge activities of WDR neurons were evaluated. Results showed that Dragon's Blood and its three components could inhibit the evoked discharge frequencies of WDR neurons in a concentration-dependent way. The Hill's coefficients describing dose-response relations of three components were different. Only the combined effect of cochinchinenin A, cochinchinenin B and Ioureirin B was similar to that of Dragons Blood. Furthermore, the combined effect was synergistic. This investigation demonstrated that through the synergistic interaction of the three components Dragon's Blood could interfere with the transmission and processing of pain signals in spinal dorsal horn. All these further proved that the combination of cochinchinenin A, cochinchinenin B, and Ioureirin B was the material basis for the analgesic effect of Dragon's Blood.

  9. Material basis for inhibition of Dragon’s Blood on evoked discharges of wide dynamic range neurons in spinal dorsal horn of rats

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In vivo experiments were designed to verify the analgesic effect of Dragon’s Blood and the material basis for this effect. Extracellular microelectrode recordings were used to observe the effects of Dragon’s Blood and various combinations of the three components (cochinchinenin A, cochinchinenin B, and loureirin B) extracted from Dragon’s Blood on the discharge activities of wide dynamic range (WDR) neurons in spinal dorsal horn (SDH) of intact male Wistar rats evoked by electric stimulation at sciatic nerve. When the Hill’s coefficients describing the dose-response relations of drugs were dif-ferent, based on the concept of dose equivalence, the equations of additivity surfaces which can be applied to assess the interaction between three drugs were derived. Adopting the equations and Tal-larida’s isobole equations used to assess the interaction between two drugs with dissimilar dose-response relations, the effects produced by various combinations of the three components in modulating the evoked discharge activities of WDR neurons were evaluated. Results showed that Dragon’s Blood and its three components could inhibit the evoked discharge frequencies of WDR neurons in a concentration-dependent way. The Hill’s coefficients describing dose-response relations of three components were different. Only the combined effect of cochinchinenin A, cochinchinenin B and loureirin B was similar to that of Dragons Blood. Furthermore, the combined effect was synergistic. This investigation demonstrated that through the synergistic interaction of the three components Dragon’s Blood could interfere with the transmission and processing of pain signals in spinal dorsal horn. All these further proved that the combination of cochinchinenin A, cochinchinenin B, and loureirin B was the material basis for the analgesic effect of Dragon’s Blood.

  10. Material basis for inhibition of Dragon's Blood on evoked discharges of wide dynamic range neurons in spinal dorsal horn of rats.

    Science.gov (United States)

    Guo, Min; Chen, Su; Liu, Xiangming

    2008-11-01

    In vivo experiments were designed to verify the analgesic effect of Dragon's Blood and the material basis for this effect. Extracellular microelectrode recordings were used to observe the effects of Dragon's Blood and various combinations of the three components (cochinchinenin A, cochinchinenin B, and loureirin B) extracted from Dragon's Blood on the discharge activities of wide dynamic range (WDR) neurons in spinal dorsal horn (SDH) of intact male Wistar rats evoked by electric stimulation at sciatic nerve. When the Hill's coefficients describing the dose-response relations of drugs were different, based on the concept of dose equivalence, the equations of additivity surfaces which can be applied to assess the interaction between three drugs were derived. Adopting the equations and Tallarida's isobole equations used to assess the interaction between two drugs with dissimilar dose-response relations, the effects produced by various combinations of the three components in modulating the evoked discharge activities of WDR neurons were evaluated. Results showed that Dragon's Blood and its three components could inhibit the evoked discharge frequencies of WDR neurons in a concentration-dependent way. The Hill's coefficients describing dose-response relations of three components were different. Only the combined effect of cochinchinenin A, cochinchinenin B and loureirin B was similar to that of Dragons Blood. Furthermore, the combined effect was synergistic. This investigation demonstrated that through the synergistic interaction of the three components Dragon's Blood could interfere with the transmission and processing of pain signals in spinal dorsal horn. All these further proved that the combination of cochinchinenin A, cochinchinenin B, and loureirin B was the material basis for the analgesic effect of Dragon's Blood.

  11. 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.

  12. Teratogenic effects of pyridoxine on the spinal cord and dorsal root ganglia of embryonic chickens.

    Science.gov (United States)

    Sharp, A A; Fedorovich, Y

    2015-03-19

    Our understanding of the role of somatosensory feedback in regulating motility during chicken embryogenesis and fetal development in general has been hampered by the lack of an approach to selectively alter specific sensory modalities. In adult mammals, pyridoxine overdose has been shown to cause a peripheral sensory neuropathy characterized by a loss of both muscle and cutaneous afferents, but predominated by a loss of proprioception. We have begun to explore the sensitivity of the nervous system in chicken embryos to the application of pyridoxine on embryonic days 7 and 8, after sensory neurons in the lumbosacral region become post-mitotic. Upon examination of the spinal cord, dorsal root ganglion and peripheral nerves, we find that pyridoxine causes a loss of neurotrophic tyrosine kinase receptor type 3-positive neurons, a decrease in the diameter of the muscle innervating nerve tibialis, and a reduction in the number of large diameter axons in this nerve. However, we found no change in the number of Substance P or calcitonin gene-related peptide-positive neurons, the number of motor neurons or the diameter or axonal composition of the femoral cutaneous nerve. Therefore, pyridoxine causes a peripheral sensory neuropathy in embryonic chickens largely consistent with its effects in adult mammals. However, the lesion may be more restricted to proprioception in the chicken embryo. Therefore, pyridoxine lesion induced during embryogenesis in the chicken embryo can be used to assess how the loss of sensation, largely proprioception, alters spontaneous embryonic motility and subsequent motor development.

  13. Do premotor interneurons act in parallel on spinal motoneurons and on dorsal horn spinocerebellar and spinocervical tract neurons in the cat?

    Science.gov (United States)

    Krutki, Piotr; Jelen, Sabina; Jankowska, Elzbieta

    2011-04-01

    It has previously been established that ventral spinocerebellar tract (VSCT) neurons and dorsal spinocerebellar tract neurons located in Clarke's column (CC DSCT neurons) forward information on actions of premotor interneurons in reflex pathways from muscle afferents on α-motoneurons. Whether DSCT neurons located in the dorsal horn (dh DSCT neurons) and spinocervical tract (SCT) neurons are involved in forwarding similar feedback information has not yet been investigated. The aim of the present study was therefore to examine the input from premotor interneurons to these neurons. Electrical stimuli were applied within major hindlimb motor nuclei to activate axon-collaterals of interneurons projecting to these nuclei, and intracellular records were obtained from dh DSCT and SCT neurons. Direct actions of the stimulated interneurons were differentiated from indirect actions by latencies of postsynaptic potentials evoked by intraspinal stimuli and by the absence or presence of temporal facilitation. Direct actions of premotor interneurons were found in a smaller proportion of dh DSCT than of CC DSCT neurons. However, they were evoked by both excitatory and inhibitory interneurons, whereas only inhibitory premotor interneurons were previously found to affect CC DSCT neurons [as indicated by monosynaptic excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) in dh DSCT and only IPSPs in CC DSCT neurons]. No effects of premotor interneurons were found in SCT neurons, since monosynaptic EPSPs or IPSPs were only evoked in them by stimuli applied outside motor nuclei. The study thus reveals a considerable differentiation of feedback information provided by different populations of ascending tract neurons.

  14. Inhibition of SNL-induced upregulation of CGRP and NPY in the spinal cord and dorsal root ganglia by the 5-HT(2A) receptor antagonist ketanserin in rats.

    Science.gov (United States)

    Wang, Dongmei; Chen, Tingjun; Gao, Yun; Quirion, Rémi; Hong, Yanguo

    2012-05-01

    Our previous study has demonstrated that topical and systemic administration of the 5-HT(2A) receptor antagonist ketanserin attenuates neuropathic pain. To explore the mechanisms involved, we examined whether ketanserin reversed the plasticity changes associated with calcitonin gene-related peptides (CGRP) and neuropeptide Y (NPY) which may reflect distinct mechanisms: involvement and compensatory protection. Behavioral responses to thermal and tactile stimuli after spinal nerve ligation (SNL) at L5 demonstrated neuropathic pain and its attenuation in the vehicle- and ketanserin-treated groups, respectively. SNL surgery induced an increase in CGRP and NPY immunoreactivity (IR) in laminae I-II of the spinal cord. L5 SNL produced an expression of NPY-IR in large, medium and small diameter neurons in dorsal root ganglion (DRG) only at L5, but not adjacent L4 and L6. Daily injection of ketanserin (0.3 mg/kg, s.c.) for two weeks suppressed the increase in CGRP-IR and NPY-IR in the spinal cord or DRG. The present study demonstrated that: (1) the expression of CGRP was enhanced in the spinal dorsal horn and NPY was expressed in the DRG containing injured neurons, but not in the adjacent DRG containing intact neurons, following L5 SNL; (2) the maladaptive changes in CGRP and NPY expression in the spinal cord and DRG mediated the bioactivity of 5-HT/5-HT(2A) receptors in neuropathic pain and (3) the blockade of 5-HT(2A) receptors by ketanserin reversed the evoked upregulation of both CGRP and NPY in the spinal cord and DRG contributing to the inhibition of neuropathic pain.

  15. Dysregulation of Kv3.4 channels in dorsal root ganglia following spinal cord injury.

    Science.gov (United States)

    Ritter, David M; Zemel, Benjamin M; Hala, Tamara J; O'Leary, Michael E; Lepore, Angelo C; Covarrubias, Manuel

    2015-01-21

    Spinal cord injury (SCI) patients develop chronic pain involving poorly understood central and peripheral mechanisms. Because dysregulation of the voltage-gated Kv3.4 channel has been implicated in the hyperexcitable state of dorsal root ganglion (DRG) neurons following direct injury of sensory nerves, we asked whether such a dysregulation also plays a role in SCI. Kv3.4 channels are expressed in DRG neurons, where they help regulate action potential (AP) repolarization in a manner that depends on the modulation of inactivation by protein kinase C (PKC)-dependent phosphorylation of the channel's inactivation domain. Here, we report that, 2 weeks after cervical hemicontusion SCI, injured rats exhibit contralateral hypersensitivity to stimuli accompanied by accentuated repetitive spiking in putative DRG nociceptors. Also in these neurons at 1 week after laminectomy and SCI, Kv3.4 channel inactivation is impaired compared with naive nonsurgical controls. At 2-6 weeks after laminectomy, however, Kv3.4 channel inactivation returns to naive levels. Conversely, Kv3.4 currents at 2-6 weeks post-SCI are downregulated and remain slow-inactivating. Immunohistochemistry indicated that downregulation mainly resulted from decreased surface expression of the Kv3.4 channel, as whole-DRG-protein and single-cell mRNA transcript levels did not change. Furthermore, consistent with Kv3.4 channel dysregulation, PKC activation failed to shorten the AP duration of small-diameter DRG neurons. Finally, re-expressing synthetic Kv3.4 currents under dynamic clamp conditions dampened repetitive spiking in the neurons from SCI rats. These results suggest a novel peripheral mechanism of post-SCI pain sensitization implicating Kv3.4 channel dysregulation and potential Kv3.4-based therapeutic interventions.

  16. Curcumin exerts antinociceptive effects by inhibiting the activation of astrocytes in spinal dorsal horn and the intracellular extracellular signal-regulated kinase signaling pathway in rat model of chronic constriction injury

    Institute of Scientific and Technical Information of China (English)

    JI Feng-tao; LIANG Jiang-jun; LIU Ling; CAO Ming-hui; LI Feng

    2013-01-01

    Background Activation of glial cells and the extracellular signal-regulated kinase (ERK) signaling pathway play an important role in the development and maintenance of neuropathic pain.Curcumin can alleviate the symptom of inflammatory pain by inhibiting the production and release of interleukin and tumor necrosis factor.However,whether curcumin affects neuropathic pain induced by nerve injury and the possible mechanism involved are still unknown.This study investigated the effects of tolerable doses of curcumin on the activation of astrocytes and ERK signaling in the spinal dorsal horn in rat model of neuropathic pain.Methods Adult male Sprague-Dawley rats were randomly divided into three groups:a control (sham operated) group,and chronic constriction injury groups (to induce neuropathic pain) that were either untreated or treated with curcumin.Thermal and mechanical hyperalgesia thresholds were measured.The distribution and morphological changes of astrocytes were observed by immunofluorescence.Western blotting was used to detect changes in the expression of glial flbrillary acid protein (GFAP) and phosphorylated ERK.Results Injured rats showed obvious mechanical allodynia and thermal hyperalgesia.The number of GFAP-positive astrocytes,and the fluorescence intensity of GFAP were significantly increased in the spinal dorsal horn of injured compared with control rats.The soma of astrocytes also appeared hypertrophied in injured animals.Expression of GFAP and phosphorylated ERK was also significantly increased in the spinal dorsal hom of injured compared with control rats.Curcumin reduced the injury-induced thermal and mechanical hyperalgesia,the increase in the fluorescence intensity of GFAP and the hypertrophy of astrocytic soma,activation of GFAP and phosphorylation of ERK in the spinal dorsal horn.Conclusions Curcumin can markedly alleviate nerve injury-induced neuropathic pain in rats.The analgesic effect of curcumin may be attributed to its inhibition of

  17. 39. Ultrastructural Changes of Neurons Located at Anterior Horn of Lumbar Spinal cord in Ethylene Oxide Exposed Mice

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mice inhaled ethylene oxide at concentration of 360 mg/m3 for two hours a day, six days a week for 14 weeks. At the end of second and third month, the neurons located at anterior horn of lumbar spinal cord were observed under transmission electron microscope and scanning electron microscope with freeze etching. The results showed that the morphological changes in neuron cells became more obvious as the inhalation period prolonged. Following changes were observed : The distribution of integrating proteins in neuron membrane changed from normal stochastic into clustered one, the endoplasmic reticulum reduced in number and appeared as small vesicles, the ribosomes attached to the surface of rough endoplasmic reticulum were also decreased in number, arranged irregularly, disintegrated or even degranulated. The numher of mitochondria was also decreased. Observed aiso were the swelling of the axons of myelinated nerve fibers and loss of stratification of their myelin sheaths. The above results indicated that the ethylene oxide can induce structural changes in neuron cells, and this inevitably may cause functional abnormality of nervous system and manifestation of neurotoxic symptoms in ethylene oxide exposed individuals.

  18. Effect of pre-electroacupuncture on p38 and c-Fos expression in the spinal dorsal horn of rats suffering from visceral pain

    Institute of Scientific and Technical Information of China (English)

    XU Ke-da; LIANG Tao; WANG Kun; TIAN De-an

    2010-01-01

    Background Acupuncture is an effective way to relieve pain, but the mechanism by which electroacupuncture (EA) decreases the visceral pain state still remains unclear. This study aimed to evaluate the effects of pre-electroacupuncture on pain behaviors, p38 phosphorylation, and c-Fos protein and mRNA expression in both the colonic wall and spinal dorsal horn of rats suffering from visceral pain. This study also investigated the probable signaling regulatory mechanism of the analgesic effect induced by electroacupuncture. Methods All rats were randomized into the control (Con) group, the Con+EA group, the visceral pain (VP) group, and VP+EA group (n=8 for all groups). The visceral pain model was established using 40 ul of 5% formalin solution injected into the colon of rats. EA was applied to the bilateral Jiaji acupoints for 20 minutes before application of visceral pain. Parameters for EA were set at a continuous wave (20 Hz) and intensity where the rats shook their whiskers but did not scrabble (≤1 mA). The visceral pain score was recorded and the expressions of p38 and c-Fos protein were detected using Western blotting. Real-time quantitative PCR was also used to determine the expression of c-Fos mRNA. Results Rats in the VP group immediately presented with obvious visceral pain behaviors after being injected with formalin. p38 activity and c-Fos protein and mRNA expression in both the colonic wall and spinal dorsal horn were higher in the VP group than in the Con group (P <0.05). By contrast, visceral pain behaviors were delayed in rats from the VP+EA group. p38 activity and c-Fos protein and mRNA expression were lower in the VP+EA group than that in the VP group (P<0.01). Conclusions Pre-electroacupuncture of the Jiaji acupoint has prophylactic analgesic effects on rats suffering from visceral pain. The p38 signal transduction pathway may be partly involved in the regulatory mechanism of this analgesic effect.

  19. Canonical BMP7 activity is required for the generation of discrete neuronal populations in the dorsal spinal cord

    Science.gov (United States)

    Le Dréau, Gwenvael; Garcia-Campmany, Lidia; Rabadán, M. Angeles; Ferronha, Tiago; Tozer, Samuel; Briscoe, James; Martí, Elisa

    2012-01-01

    BMP activity is essential for many steps of neural development, including the initial role in neural induction and the control of progenitor identities along the dorsal-ventral axis of the neural tube. Taking advantage of chick in ovo electroporation, we show a novel role for BMP7 at the time of neurogenesis initiation in the spinal cord. Using in vivo loss-of-function experiments, we show that BMP7 activity is required for the generation of three discrete subpopulations of dorsal interneurons: dI1-dI3-dI5. Analysis of the BMP7 mouse mutant shows the conservation of this activity in mammals. Furthermore, this BMP7 activity appears to be mediated by the canonical Smad pathway, as we demonstrate that Smad1 and Smad5 activities are similarly required for the generation of dI1-dI3-dI5. Moreover, we show that this role is independent of the patterned expression of progenitor proteins in the dorsal spinal cord, but depends on the BMP/Smad regulation of specific proneural proteins, thus narrowing this BMP7 activity to the time of neurogenesis. Together, these data establish a novel role for BMP7 in primary neurogenesis, the process by which a neural progenitor exits the cell cycle and enters the terminal differentiation pathway. PMID:22159578

  20. Loss of Hoxb8 alters spinal dorsal laminae and sensory responses in mice

    NARCIS (Netherlands)

    J.C. Holstege (Jan); W. de Graaff (Wim); S.M. Hossaini (Mehdi); S.C. Cano; D. Jaarsma (Dick); J. Deschamps (Jacqueline); E. van den Akker (Eric)

    2008-01-01

    textabstractAlthough Hox gene expression has been linked to motoneuron identity, a role of these genes in development of the spinal sensory system remained undocumented. Hoxb genes are expressed at high levels in the dorsal horn of the spinal cord. Hoxb8 null mutants manifest a striking phenotype of

  1. Loss of Hoxb8 alters spinal dorsal laminae and sensory responses in mice.

    NARCIS (Netherlands)

    Holstege, J.C.; de Graaff, W.G.A.J.; Hossaini, M.; Cano, S.C.; Jaarsma, D.; van den Akker, E.; Deschamps, J.

    2008-01-01

    Although Hox gene expression has been linked to motoneuron identity, a role of these genes in development of the spinal sensory system remained undocumented. Hoxb genes are expressed at high levels in the dorsal horn of the spinal cord. Hoxb8 null mutants manifest a striking phenotype of excessive g

  2. Modulation of Matrix Metalloproteinases Activity in the Ventral Horn of the Spinal Cord Re-stores Neuroglial Synaptic Homeostasis and Neurotrophic Support following Peripheral Nerve Injury.

    Directory of Open Access Journals (Sweden)

    Giovanni Cirillo

    Full Text Available Modulation of extracellular matrix (ECM remodeling after peripheral nerve injury (PNI could represent a valid therapeutic strategy to prevent maladaptive synaptic plasticity in central nervous system (CNS. Inhibition of matrix metalloproteinases (MMPs and maintaining a neurotrophic support could represent two approaches to prevent or reduce the maladaptive plastic changes in the ventral horn of spinal cord following PNI. The purpose of our study was to analyze changes in the ventral horn produced by gliopathy determined by the suffering of motor neurons following spared nerve injury (SNI of the sciatic nerve and how the intrathecal (i.t. administration of GM6001 (a MMPs inhibitor or the NGF mimetic peptide BB14 modulate these events. Immunohistochemical analysis of spinal cord sections revealed that motor neuron disease following SNI was associated with increased microglial (Iba1 and astrocytic (GFAP response in the ventral horn of the spinal cord, indicative of reactive gliosis. These changes were paralleled by decreased glial aminoacid transporters (glutamate GLT1 and glycine GlyT1, increased levels of the neuronal glutamate transporter EAAC1, and a net increase of the Glutamate/GABA ratio, as measured by HPLC analysis. These molecular changes correlated to a significant reduction of mature NGF levels in the ventral horn. Continuous i.t. infusion of both GM6001 and BB14 reduced reactive astrogliosis, recovered the expression of neuronal and glial transporters, lowering the Glutamate/GABA ratio. Inhibition of MMPs by GM6001 significantly increased mature NGF levels, but it was absolutely ineffective in modifying the reactivity of microglia cells. Therefore, MMPs inhibition, although supplies neurotrophic support to ECM components and restores neuro-glial transporters expression, differently modulates astrocytic and microglial response after PNI.

  3. Comparative immunohistochemical localisation of GABA(B1a), GABA(B1b) and GABA(B2) subunits in rat brain, spinal cord and dorsal root ganglion.

    Science.gov (United States)

    Charles, K J; Evans, M L; Robbins, M J; Calver, A R; Leslie, R A; Pangalos, M N

    2001-01-01

    GABA(B) receptors are G-protein-coupled receptors mediating the slow onset and prolonged synaptic actions of GABA in the CNS. The recent cloning of two genes, GABA(B1) and GABA(B2), has revealed a novel requirement for GABA(B) receptor signalling. Studies have demonstrated that the two receptor subunits associate as a GABA(B1)/GABA(B2) heterodimer to form a functional GABA(B) receptor. In this study we have developed polyclonal antisera specific to two splice variants of the GABA(B1) subunit, GABA(B1a) and GABA(B1b), as well as an antiserum to the GABA(B2) subunit. Using affinity-purified antibodies derived from these antisera we have mapped out the distribution profile of each subunit in rat brain, spinal cord and dorsal root ganglion. In brain the highest areas of GABA(B1a), GABA(B1b) and GABA(B2) subunit expression were found in neocortex, hippocampus, thalamus, cerebellum and habenula. In spinal cord, GABA(B1) and GABA(B2) subunits were expressed in the superficial layers of the dorsal horn, as well as in motor neurones in the deeper layers of the ventral horn. GABA(B) receptor subunit immunoreactivity in dorsal root ganglion suggested that expression of GABA(B1b) was restricted to the large diameter neurones, in contrast to GABA(B1a) and GABA(B2) subunits which were expressed in both large and small diameter neurones. Although expression levels of GABA(B1) and GABA(B2) subunits varied we found no areas in which GABA(B1) was expressed in the absence of GABA(B2). This suggests that most, if not all, GABA(B1) immunoreactivity may represent functional GABA(B) receptors. Although our data are in general agreement with functional studies, some discrepancies in GABA(B1) subunit expression occurred with respect to other immunohistochemical studies. Overall our data suggest that GABA(B) receptors are widely expressed throughout the brain and spinal cord, and that GABA(B1a) and GABA(B1b) subunits can associate with GABA(B2) to form both pre- and post-synaptic receptors.

  4. Intrathecal baclofen, a GABAB receptor agonist, inhibits the expression of p-CREB and NR2B in the spinal dorsal horn in rats with diabetic neuropathic pain.

    Science.gov (United States)

    Liu, Peng; Guo, Wen-Ya; Zhao, Xiao-Nan; Bai, Hui-Ping; Wang, Qian; Wang, Xiu-Li; Zhang, Ying-Ze

    2014-08-01

    This study aimed to investigate the effect of baclofen, a γ-aminobutyric acid B (GABAB) receptor agonist, on the expression of p-CREB and NR2B in the spinal dorsal horn of rats with diabetic neuropathic pain (DNP). The DNP rats, which were successfully induced with streptozocin, were distributed among 3 groups that were treated with saline (D1 group), baclofen (D2 group), or CGP55845 + baclofen (D3 group) continuously for 4 days. The rats induced with saline and subsequently treated with saline were used as controls (C group). The times for the paw withdrawal threshold and thermal withdrawal latency of the D1 group were lower than those for the C group, and were significantly increased after baclofen treatment, but not when GABA receptor was pre-blocked with CGP55845 (D3 group). Increased protein expression levels of NR2B and p-CREB and mRNA levels of NR2B were found in the D1 group when compared with the controls. Baclofen treatment significantly suppressed their expression, bringing it close to the levels of controls. However, in the D3 group, the expression of p-CREB and NR2B were still significantly higher than that of the controls. Activation of GABAB receptor by baclofen attenuates diabetic neuropathic pain, which may partly be accomplished via down-regulating the expression of p-CREB and NR2B.

  5. Phosphorylation of the GluN1 subunit in dorsal horn neurons by remifentanil: a mechanism for opioid-induced hyperalgesia.

    Science.gov (United States)

    Zhang, C; Li, S S; Zhao, N; Yu, C

    2015-03-13

    Remifentanil (an ultra-short acting μ-opioid receptor agonist) use has been associated with acute opioid tolerance and hyperalgesia. Previous electrophysiological studies have shown that remifentanil elicits rapid and prolonged upregulation of N-methyl-D-aspartate receptor (NMDAR) currents. However, the effect of remifentanil on the levels of the GluN1 subunit of the NMDAR in dorsal horn neurons (DHNs) has not been reported. We investigated the effect of remifentanil, along with ketamine (NMDAR antagonist) and naloxone (μ-opioid receptor antagonist), on GluN1 mRNA levels and the amount of phosphorylated GluN1 in primary cultures of embryonic rat DHNs. DHNs were isolated from 18-19-day rat embryos and treated with remifentanil or vehicle for 1 h. GluN1 mRNA and protein levels, determined by real time reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively, were significantly and persistently increased by remifentanil exposure compared with the control group (P < 0.05). These results may partially account for the mechanism of remifentanil-induced hyperalgesia. This increase was prevented by ketamine (NMDAR antagonist) and naloxone (μ-opioid receptors antagonist), thus providing a potential therapeutic mechanism for the prevention of opioid-induced hyperalgesia.

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

    Directory of Open Access Journals (Sweden)

    Misa Oyama

    2017-03-01

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

  7. A Comparative Study of Three Interneuron Types in the Rat Spinal Cord

    Science.gov (United States)

    Zhu, Yaxi; Liu, Zongwei; Wang, Weiping; Wei, Jiayou; Li, Keyi; Wu, Jiajia; Chen, Zhi; Li, Youlan; Mu, Shuhua; OuYang, Lisi; Lei, Wanlong

    2016-01-01

    Interneurons are involved in the physiological function and the pathomechanism of the spinal cord. Present study aimed to examine and compare the characteristics of Cr+, Calb+ and Parv+ interneurons in morphology and distribution by using immunhistochemical and Western blot techniques. Results showed that 1) Cr-Calb presented a higher co-existence rate than that of Cr-Parv, and both of them were higher in the ventral horn than in the dosal horn; 2) Cr+, Calb+ and Parv+ neurons distributing zonally in the superficial dosal horn were small-sized. Parv+ neuronswere the largest, and Cr+ and Calb+ neurons were higher density among them. In the deep dorsal horn, Parv+ neurons were mainly located in nucleus thoracicus and the remaining scatteredly distributed. Cr+ neuronal size was the largest, and Calb+ neurons were the least among three interneuron types; 3) Cr+, Calb+ and Parv+ neurons of ventral horns displayed polygonal, round and fusiform, and Cr+ and Parv+ neurons were mainly distributed in the deep layer, but Calb+ neurons mainly in the superficial layer. Cr+ neurons were the largest, and distributed more in ventral horns than in dorsal horns; 4) in the dorsal horn of lumbar cords, Calb protein levels was the highest, but Parv protein level in ventral horns was the highest among the three protein types. Present results suggested that the morphological characteristics of three interneuron types imply their physiological function and pathomechanism relevance. PMID:27658248

  8. A Comparative Study of Three Interneuron Types in the Rat Spinal Cord.

    Science.gov (United States)

    Chen, Si; Yang, Guangqi; Zhu, Yaxi; Liu, Zongwei; Wang, Weiping; Wei, Jiayou; Li, Keyi; Wu, Jiajia; Chen, Zhi; Li, Youlan; Mu, Shuhua; OuYang, Lisi; Lei, Wanlong

    Interneurons are involved in the physiological function and the pathomechanism of the spinal cord. Present study aimed to examine and compare the characteristics of Cr+, Calb+ and Parv+ interneurons in morphology and distribution by using immunhistochemical and Western blot techniques. Results showed that 1) Cr-Calb presented a higher co-existence rate than that of Cr-Parv, and both of them were higher in the ventral horn than in the dosal horn; 2) Cr+, Calb+ and Parv+ neurons distributing zonally in the superficial dosal horn were small-sized. Parv+ neuronswere the largest, and Cr+ and Calb+ neurons were higher density among them. In the deep dorsal horn, Parv+ neurons were mainly located in nucleus thoracicus and the remaining scatteredly distributed. Cr+ neuronal size was the largest, and Calb+ neurons were the least among three interneuron types; 3) Cr+, Calb+ and Parv+ neurons of ventral horns displayed polygonal, round and fusiform, and Cr+ and Parv+ neurons were mainly distributed in the deep layer, but Calb+ neurons mainly in the superficial layer. Cr+ neurons were the largest, and distributed more in ventral horns than in dorsal horns; 4) in the dorsal horn of lumbar cords, Calb protein levels was the highest, but Parv protein level in ventral horns was the highest among the three protein types. Present results suggested that the morphological characteristics of three interneuron types imply their physiological function and pathomechanism relevance.

  9. 幻肢痛大鼠脊髓背角神经元和突触数量的变化%Changes in the number of synapses and neurons in spinal dorsal horn in a rat model of phantom limb pain

    Institute of Scientific and Technical Information of China (English)

    林菁艳; 彭彬; 杨正伟; 闵苏

    2010-01-01

    Objective To investigate the changes in the number of synapses and neurons in the spinal dorsal horn in a rat model of phantom limb pain. Methods Eleven healthy adult SD rats of both sexes weighing 209-300 g were randomly divided into 2 groups: sham operation group (group S, n = 5) and phantom limb pain group (group P, n = 6). Phantom limb pain was induced by resection of a 0.5 cm segment of unilateral sciatic nerve in group P. In group S unilateral sciatic nerve was exposed but not transected. The animals were observed for autotomy and scored (0 = no autotomy, 13 = the worst autotomy) after operation and were sacrificed on the 28th day after operation. The L3-6 segment of the spinal cord was removed for determination of the number of neurons (by Nissl's staining) and synapses (by synaptophysin immuno-histochemistry).Results In group S no animal developed autotomy. In group P autotomy started from the 2nd day after operation and the score reached 9-11. The number of the neurons in the spinal dorsal horn in all 4 segments and the number of synapses in L3 and 16 segments were comparable between the two sides and the 2 groups. The number of synapses in the spinal dorsal horn of L4and L5 segment was significantly larger in the operated side than in the contralateral side in group P. Conclusion The number of synapses in the spinal dorsal horn significantly increases in animals with plantom limb pain which induces no increase in the number of neurons in the spinal dorsal horn.%目的 探讨幻肢痛大鼠脊髓背角神经元和突触数量的变化.方法 健康成年SD大鼠11只,雄雌不拘,体重290~300 g,随机分为2组:假手术组(S组,n=5)和单侧坐骨神经横断组(P组,n=6).术后持续观察P组大鼠自噬情况,并进行自噬评分.术后28 d时,取L3~6节段脊髓组织,分别进行尼氏染色(显示神经元)和突触素免疫组织化学染色(显示突触数量),计数手术侧和非手术侧脊髓背角神经元和突触的数量.结果 P

  10. Third-Degree Hindpaw Burn Injury Induced Apoptosis of Lumbar Spinal Cord Ventral Horn Motor Neurons and Sciatic Nerve and Muscle Atrophy in Rats

    Directory of Open Access Journals (Sweden)

    Sheng-Hua Wu

    2015-01-01

    Full Text Available Background. Severe burns result in hypercatabolic state and concomitant muscle atrophy that persists for several months, thereby limiting patient recovery. However, the effects of burns on the corresponding spinal dermatome remain unknown. This study aimed to investigate whether burns induce apoptosis of spinal cord ventral horn motor neurons (VHMNs and consequently cause skeletal muscle wasting. Methods. Third-degree hindpaw burn injury with 1% total body surface area (TBSA rats were euthanized 4 and 8 weeks after burn injury. The apoptosis profiles in the ventral horns of the lumbar spinal cords, sciatic nerves, and gastrocnemius muscles were examined. The Schwann cells in the sciatic nerve were marked with S100. The gastrocnemius muscles were harvested to measure the denervation atrophy. Result. The VHMNs apoptosis in the spinal cord was observed after inducing third-degree burns in the hindpaw. The S100 and TUNEL double-positive cells in the sciatic nerve increased significantly after the burn injury. Gastrocnemius muscle apoptosis and denervation atrophy area increased significantly after the burn injury. Conclusion. Local hindpaw burn induces apoptosis in VHMNs and Schwann cells in sciatic nerve, which causes corresponding gastrocnemius muscle denervation atrophy. Our results provided an animal model to evaluate burn-induced muscle wasting, and elucidate the underlying mechanisms.

  11. Localization of Brain Natriuretic Peptide Immunoreactivity in Rat Spinal Cord

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    Essam M Abdelalim

    2016-12-01

    Full Text Available Brain natriuretic peptide (BNP exerts its functions through natriuretic peptide receptors. Recently, BNP has been shown to be involved in a wide range of functions. Previous studies reported BNP expression in the sensory afferent fibers in the dorsal horn of the spinal cord. However, BNP expression and function in the neurons of the central nervous system are still controversial. Therefore, in this study, we investigated BNP expression in the rat spinal cord in detail using RT-PCR and immunohistochemistry. RT-PCR analysis showed that BNP mRNA was present in the spinal cord and DRG. BNP immunoreactivity was observed in different structures of the spinal cord, including the neuronal cell bodies and neuronal processes. BNP immunoreactivity was observed in the dorsal horn of the spinal cord and in the neurons of the intermediate column and ventral horn. Double-immunolabeling showed a high level of BNP expression in the afferent fibers (laminae I-II labeled with calcitonin gene-related peptide (CGRP, suggesting BNP involvement in sensory function. In addition, BNP was co-localized with CGRP and choline acetyltransferase in the motor neurons of the ventral horn. Together, these results indicate that BNP is expressed in sensory and motor systems of the spinal cord, suggesting its involvement in several biological actions on sensory and motor neurons via its binding to NPR-A and/or NPR-B in the DRG and spinal cord.

  12. The search for novel analgesics: re-examining spinal cord circuits with new tools

    Directory of Open Access Journals (Sweden)

    Kelly M Smith

    2014-02-01

    Full Text Available In this perspective, we propose the absence of detailed information regarding spinal cord circuits that process sensory information remains a major barrier to advancing analgesia. We highlight recent advances showing that functionally discrete populations of neurons in the spinal cord dorsal horn play distinct roles in processing sensory information. We then discuss new molecular, electrophysiological, and optogenetic techniques that can be employed to understand how dorsal horn circuits process tactile and nociceptive information. We believe this information can drive the development of entirely new classes of pharmacotherapies that target key elements in spinal circuits to selectively modify sensory function and blunt pain.

  13. [Left hand clumsiness due to disturbance of kinesthesia after damage to the dorsal column of the high cervical cord].

    Science.gov (United States)

    Hashimoto, R; Kanho, M; Fujimoto, K; Tanaka, Y

    1997-04-01

    We described a 48-year-old, right-handed woman who manifested left hand clumsiness after damage to the dorsal column of the high cervical cord due to probable multiple sclerosis. On February 29, 1996, she developed a weakness in the right limbs. Subsequently, she suffered numbness and clumsiness in the left limbs, even though muscle strength of the left limbs was preserved. Seventeen days later, she was referred to our hospital. A T2-weighted MRI after admission demonstrated high signal intensities in the left dorsal column and the right antero-lateral part of the cervical cord at the C1 to C3 vertebral level. Under the diagnosis of probable multiple sclerosis, steroid pulse therapy was applied twice and she gradually regained muscle strength in the right limbs and sensation in the left limbs. One month later, elemental sensations such as pain, touch, temperature, vibration, and position, as well as discriminative sensations such as localization sensation, two-point discrimination, barognosis, pinch-press discrimination, and graphesthesia in the left limbs returned to normal. However, her left hand remained clumsy, especially when she tried to manipulate objects. She also showed a great difficulty in sustaining a constant level of pinching force by the left thumb and index finger, and in localizing her right thumb placed in space with the left hand with her eyes closed. She stated herself that she could not sense at all how her left hand and fingers were moving. Somatosensory evoked potentials recorded from the right scalp showed that the NI was poorly organized and the patency of subsequent peaks was delayed. Transcranial magnetic stimulation revealed that the pyramidal tract from the right motor cortex to the left cervical cord was functionally intact. These observations lead us to conclude as follows: (1) the patient's left hand clumsiness is probably due to the disturbance of kinesthesia, which is crucial to activate temporo-spatial patterns of complex hand and

  14. Tumor necrosis factor α sensitizes spinal cord TRPV1 receptors to the endogenous agonist N-oleoyldopamine

    OpenAIRE

    2010-01-01

    Abstract Modulation of synaptic transmission in the spinal cord dorsal horn is thought to be involved in the development and maintenance of different pathological pain states. The proinflamatory cytokine, tumor necrosis factor α (TNFα), is an established pain modulator in both the peripheral and the central nervous system. Up-regulation of TNFα and its receptors (TNFR) in dorsal root ganglion (DRG) cells and in the spinal cord has been shown to play an important role in neuropathic and inflam...

  15. Dorsal border periaqueductal gray neurons project to the area directly adjacent to the central canal ependyma of the C4-T8 spinal cord in the cat.

    Science.gov (United States)

    Mouton, L J; Kerstens, L; Van der Want, J; Holstege, G

    1996-11-01

    In a previous study horseradish peroxidase (HRP) injections in the upper thoracic and cervical spinal cord revealed some faintly labeled small neurons at the dorsal border of the periaqueductal gray (PAG). The present light microscopic and electronmicroscopic tracing study describes the precise location of these dorsal border PAG-spinal neurons and their terminal organization. Wheat germ agglutinin-conjugated HRP (WGA-HRP) injections into cervical and upper thoracic spinal segments resulted in several hundreds of small retrogradely labeled neurons at the dorsal border of the ipsilateral caudal PAG. These neurons were not found after injections in more caudal segments. WGA-HRP injections in the dorsal border PAG region surprisingly resulted in anterogradely labeled fibers terminating in the area dorsally and laterally adjoining the central canal ependyma of the C4-T8 spinal cord. No anterogradely labeled fibers were found more caudal in the spinal cord. The labeled fibers found in the upper cervical cord were not located in the area immediately adjoining the ependymal layer of the central canal, but in the lateral part of laminae VI, VII and VIII and in area X bilaterally. Electronmicroscopic results of one case show that the dorsal border PAG-spinal neurons terminate in the neuropil of the subependymal area and in the vicinity of the basal membranes of capillaries located laterally to the central canal. The terminal profiles contain electron-lucent and densecored vesicles, suggesting a heterogeneity of possible transmitters. A striking observation was the lack of synaptic contacts, suggesting nonsynaptic release from the profiles. The function of the dorsal border PAG-spinal projection is unknown, but considering the termination pattern of the dorsal border PAG neurons on the capillaries the intriguing similarity between this projection system and the hypothalamohypophysial system is discussed.

  16. Time Course of Immediate Early Gene Protein Expression in the Spinal Cord following Conditioning Stimulation of the Sciatic Nerve in Rats

    NARCIS (Netherlands)

    Bojovic, Ognjen; Panja, Deb; Bittins, Margarethe; Bramham, Clive R.; Tjolsen, Arne

    2015-01-01

    Long-term potentiation induced by conditioning electrical stimulation of afferent fibers is a widely studied form of synaptic plasticity in the brain and the spinal cord. In the spinal cord dorsal horn, long-term potentiation is induced by a series of high-frequency trains applied to primary

  17. Time Course of Immediate Early Gene Protein Expression in the Spinal Cord following Conditioning Stimulation of the Sciatic Nerve in Rats

    NARCIS (Netherlands)

    Bojovic, Ognjen; Panja, Deb; Bittins, Margarethe; Bramham, Clive R.; Tjolsen, Arne

    2015-01-01

    Long-term potentiation induced by conditioning electrical stimulation of afferent fibers is a widely studied form of synaptic plasticity in the brain and the spinal cord. In the spinal cord dorsal horn, long-term potentiation is induced by a series of high-frequency trains applied to primary afferen

  18. Morphological, neurochemical and electrophysiological features of parvalbumin-expressing cells: a likely source of axo-axonic inputs in the mouse spinal dorsal horn

    Science.gov (United States)

    Hughes, D I; Sikander, S; Kinnon, C M; Boyle, K A; Watanabe, M; Callister, R J; Graham, B A

    2012-01-01

    Axo-axonic synapses on the central terminals of primary afferent fibres modulate sensory input and are the anatomical correlate of presynaptic inhibition. Although several classes of primary afferents are under such inhibitory control, the origin of these presynaptic inputs in the dorsal horn is unknown. Here, we characterize the neurochemical, anatomical and electrophysiological properties of parvalbumin (PV)-expressing cells in wild-type and transgenic mice where enhanced green fluorescent protein (eGFP) is expressed under the PV promoter. We show that most PV cells have either islet or central cell-like morphology, receive inputs from myelinated primary afferent fibres and are concentrated in laminae II inner and III. We also show that inhibitory PV terminals in lamina II inner selectively target the central terminals of myelinated afferents (∼80% of 935 PVeGFP boutons) and form axo-axonic synapses (∼75% of 71 synapses from PV boutons). Targeted whole-cell patch-clamp recordings from PVeGFP positive cells in laminae II and III showed action potential discharge was restricted to the tonic firing and initial bursting patterns (67% and 33% respectively; n = 18), and virtually all express Ih subthreshold voltage-gated currents (94%; n = 18). These neurons show higher rheobase current than non-eGFP cells but respond with high frequency action potential discharge upon activation. Together, our findings show that PV neurons in laminae II and III are a likely source of inhibitory presynaptic input on to myelinated primary afferents. Consequently PV cells are ideally placed to play an important role in the development of central sensitization and tactile allodynia. PMID:22674718

  19. Co-existence of calcium-binding proteins and γ-aminobutyric acid or glycine in neurons of the rat medullary dorsal horn

    Institute of Scientific and Technical Information of China (English)

    王文; 武胜昔; 李云庆

    2004-01-01

    Background We investigated the co-expression of calbindin-D28k (CB), calretinin (CR) and parvalbumin (PV, a combination of the three is referred to as CaBPs) with γ-aminobutyric acid (GABA) or glycine in neurons of the rat medullary dorsal horn (MDH).Methods Immunofluorescence histochemical double-staining for CaBPs and GABA or glycine was performed on the sections from rat MDH.Results CB-, CR-, PV-, GABA- and glycine-like immunoreactive (LI) neurons were differentially observed in all layers of the MDH, but particularly in lamina Ⅱ. Neurons that exhibited immunoreactivity for both CaBPs and GABA or glycine were also observed mainly in lamina Ⅱ. A few of them were found in laminae I and III. The percentages of neurons which co-expressed CB/GABA or CB/glycine out of the total numbers of CB- and GABA-LI neurons or CB- and glycine-LI neurons were 5.3% and 12.1% or 4.1% and 10.0%, respectively. The ratios of CR/GABA or CR/glycine co-existing neurons out of the total numbers of CR- and GABA-LI neurons or CR- and glycine-LI neurons were 5.8% and 7.6% or 4.4% and 7.1%, respectively. The rates of PV/GABA or PV/glycine co-localized neurons out of the total numbers of PV- and GABA-LI neurons or PV- and glycine-LI neurons were 11.1% and 5.1% or 9.9% and 5.1%, respectively. Conclusion The results indicate that some neurons in the MDH contain both CaBPs and GABA or glycine.

  20. Systemic administration of lidocaine suppresses the excitability of rat cervical dorsal horn neurons and tooth-pulp-evoked jaw-opening reflex.

    Science.gov (United States)

    Takeda, Mamoru; Oshima, Katsuo; Takahashi, Masayuki; Matsumoto, Shigeji

    2009-10-01

    Although systemic lidocaine has been demonstrated to have analgesic actions in neuropathic pain conditions, the effect of intravenous lidocaine on trigeminal pain has not been elucidated. The aim of the present study is to investigate the effect of intravenous lidocaine administration on the excitability of the upper cervical dorsal horn (C1) neuron having convergent inputs from both tooth-pulp (TP) and facial skin as well as nociceptive jaw-opening reflex (JOR). After electrical stimulation of TP, extracellular single-unit recordings from 19 C1 neurons and the digastric muscle electromyogram (dEMG) were made in pentobarbital-anesthetized rats. These neurons also responded to non-noxious and noxious mechanical stimulation (touch and pinch) of facial skin, and every neuron was considered to be a wide dynamic range (WDR) neuron. The TP-evoked C1 neuronal and dEMG activities were dose-dependently inhibited by systematic administration of lidocaine (1-2 mg/kg, i.v.). After intravenous injection of lidocaine, the unit discharges induced by both touch and pinch stimuli were inhibited, and the size of the receptive field for pinch was also significantly decreased. The mean spontaneous discharge frequencies were significantly inhibited by the application of lidocaine. These changes were reversed within -20 min. These results suggest that in the absence of neuropathic pain intravenous lidocaine injection suppresses the trigeminal nociceptive reflex as well as the excitability of C1 neurons having convergent inputs from TP and somatic afferents. Systemic lidocaine administration, therefore, may contribute to the alleviation of trigeminal-referred pain associated with tooth pain.

  1. NR2B phosphorylation at tyrosine 1472 in spinal dorsal horn contributed to N-methyl-D-aspartate-induced pain hypersensitivity in mice.

    Science.gov (United States)

    Li, Shuai; Cao, Jing; Yang, Xian; Suo, Zhan-Wei; Shi, Lei; Liu, Yan-Ni; Yang, Hong-Bin; Hu, Xiao-Dong

    2011-11-01

    Calcium influx via N-methyl-D-aspartate (NMDA)-subtype glutamate receptors (NMDARs) regulates the intracellular trafficking of NMDARs, leading to long-lasting modification of NMDAR-mediated synaptic transmission that is involved in development, learning, and synaptic plasticity. The present study investigated the contribution of such NMDAR-dependent synaptic trafficking in spinal dorsal horn to the induction of pain hypersensitivity. Our data showed that direct activation of NMDARs by intrathecal NMDA application elicited pronounced mechanical allodynia in intact mice, which was concurrent with a specific increase in the abundance of NMDAR subunits NR1 and NR2B at the postsynaptic density (PSD)-enriched fraction. Selective inhibition of NR2B-containing NMDARs (NR2BR) by ifenprodil dose dependently attenuated the mechanical allodynia in NMDA-injected mice, suggesting the importance of NR2BR synaptic accumulation in NMDA-induced pain sensitization. The NR2BR redistribution at synapses after NMDA challenge was associated with a significant increase in NR2B phosphorylation at Tyr1472, a catalytic site by Src family protein tyrosine kinases (SFKs) that has been shown to prevent NR2B endocytosis. Intrathecal injection of a specific SFKs inhibitor, PP2, to block NR2B tyrosine phosphorylation eliminated NMDA-induced NR2BR synaptic expression and also attenuated the mechanical allodynia. These data suggested that activation of spinal NMDARs was able to accumulate NR2BR at synapses via SFK signaling, which might exaggerate NMDAR-dependent nociceptive transmission and contribute to NMDA-induced nociceptive behavioral hyperresponsiveness.

  2. Expression of acetylated histone 3 in the spinal cord and the effect of morphine on inflammatory pain in rats

    Institute of Scientific and Technical Information of China (English)

    Hua Li; Changqi Li; Ruping Dai; Xudan Shi; Junmei Xu; Jianyi Zhang; Xinfu Zhou; Zhiyuan Li; Xuegang Luo

    2012-01-01

    In this study, a rat model of inflammatory pain was produced by injecting complete Freund's adjuvant into the hind paw, and the expression of acetylated histone 3 in the spinal cord dorsal horn was examined using immunohistochemical staining.One day following injection, there was a dramatic decrease in acetylated histone 3 expression in spinal cord dorsal horn neurons.However, on day 7, expression recovered in adjuvant-injected rats.While acetylated histone 3 labeling was present in dorsal horn neurons, it was more abundant in astrocytes and microglial cells.The recovery of acetylated histone 3 expression was associated with a shift in expression of the protein from neurons to glial cells.Morphine injection significantly upregulated the expression of acetylated histone 3 in spinal cord dorsal horn neurons and glial cells 1 day after injection, especially in astrocytes, preventing the transient downregulation.Our results indicate that inflammatory pain induces a transient downregulation of acetylated histone 3 in the spinal cord dorsal horn at an early stage following adjuvant injection, and that this effect can be reversed by morphine.Thus, the downregulation of acetylated histone 3 may be involved in the development of inflammatory pain.

  3. Activation of Mas oncogene-related gene (Mrg) C receptors enhances morphine-induced analgesia through modulation of coupling of μ-opioid receptor to Gi-protein in rat spinal dorsal horn.

    Science.gov (United States)

    Wang, D; Chen, T; Zhou, X; Couture, R; Hong, Y

    2013-12-03

    Mas oncogene-related gene (Mrg) G protein-coupled receptors are exclusively expressed in small-sized neurons in trigeminal and dorsal root ganglia (DRG) in mammals. The present study investigated the effect of MrgC receptor activation on morphine analgesic potency and addressed its possible mechanisms. Intrathecal (i.t.) administration of the specific MrgC receptor agonist bovine adrenal medulla 8-22 (BAM8-22, 3 nmol) increased morphine-induced analgesia and shifted the morphine dose-response curve to the left in rats. Acute morphine (5 μg) reduced the coupling of μ-opioid receptors (MORs) to Gi-, but not Gs-, protein in the spinal dorsal horn. The i.t. BAM8-22 (3 nmol) prevented this change of G-protein repertoire while the inactive MrgC receptor agonist BAM8-18 (3 nmol, i.t.) failed to do so. A double labeling study showed the co-localization of MrgC and MORs in DRG neurons. The i.t. BAM8-22 also increased the coupling of MORs to Gi-protein and recruited Gi-protein from cytoplasm to the cell membrane in the spinal dorsal horn. Application of BAM8-22 (10nM) in the cultured ganglion explants for 30 min increased Gi-protein mRNA, but not Gs-protein mRNA. The present study demonstrated that acute administration of morphine inhibited the repertoire of MOR/Gi-protein coupling in the spinal dorsal horn in vivo. The findings highlight a novel mechanism by which the activation of MrgC receptors can modulate the coupling of MORs with Gi-protein to enhance morphine-induced analgesia. Hence, adjunct treatment of MrgC agonist BAM8-22 may be of therapeutic value to relieve pain.

  4. 异丙酚对正常大鼠脊髓背角感觉神经元反应性的抑制作用%Inhibitory effects of spinal propofol on the responses of spinal dorsal horn neurons in normal rats

    Institute of Scientific and Technical Information of China (English)

    孙焱芫; 李开诚; 陈军

    2004-01-01

    脊髓背角感觉神经元不仅在感觉信息的传递和调节中起到重要作用,也是各种内源性和外源性药物的作用靶位.为了解静脉麻醉剂异丙酚是否对背角感觉神经元的反应性具有调节作用,本实验采用在体单细胞胞外记录技术,观察了脊髓背表面直接滴注0.5 μmol异丙酚对戊巴比妥钠麻醉大鼠脊髓背角广动力域(WDR)神经元和低阈值机械感受型(LTM)神经元反应性的影响.实验发现,异丙酚能抑制背角WDR神经元由施加于外周感受野伤害性热刺激(45、47、49和53℃,15 s)和夹捏机械刺激(10 s)诱发的反应性,与DMSO对照组比较具有显著性统计学差异(P<0.05);同样,异丙酚对非伤害性机械刺激诱发的WDR或LTM神经元的反应性也具有显著的抑制作用(P<0.05).本结果提示,异丙酚可直接作用于正常大鼠脊髓背角神经元,对由非伤害性和伤害性纤维介导的神经元反应性均产生抑制作用,因此异丙酚的脊髓抗伤害作用可能不是特异性的.%Spinal dorsal horn neurons play an important role in the processing of sensory information and are also targets of modulation by both endogenous and exogenous drugs. Propofol is an intravenous anesthetic and whether it has direct modulatory actions on sensory neuronal responses of the spinal cord dorsal horn has not been well studied. In the present study, a single dose (0.5 ?mol) of propofol dissolved in dimethyl sulfoxide (DMSO) was directly applied onto the dorsal surface of the spinal cord and its effect was evaluated in 25 wide-dynamicrange (WDR) neurons and 10 low-threshold mechanoreceptive (LTM) neurons by using extracellular single unit recording technique in sodium pentobarbital anesthetized rats. Compared with the DMSO treatment, propofol produced a significant inhibition of WDR neuronal activity evoked by both noxious heat (45, 47, 49 or 53℃, 15 s) and mechanical (pinch, 10 s) stimuli applied to their cutaneous receptive

  5. Expression of the immunoglobulin superfamily cell adhesion molecules in the developing spinal cord and dorsal root ganglion.

    Science.gov (United States)

    Gu, Zirong; Imai, Fumiyasu; Kim, In Jung; Fujita, Hiroko; Katayama, Kei ichi; Mori, Kensaku; Yoshihara, Yoshihiro; Yoshida, Yutaka

    2015-01-01

    Cell adhesion molecules belonging to the immunoglobulin superfamily (IgSF) control synaptic specificity through hetero- or homophilic interactions in different regions of the nervous system. In the developing spinal cord, monosynaptic connections of exquisite specificity form between proprioceptive sensory neurons and motor neurons, however, it is not known whether IgSF molecules participate in regulating this process. To determine whether IgSF molecules influence the establishment of synaptic specificity in sensory-motor circuits, we examined the expression of 157 IgSF genes in the developing dorsal root ganglion (DRG) and spinal cord by in situ hybridization assays. We find that many IgSF genes are expressed by sensory and motor neurons in the mouse developing DRG and spinal cord. For instance, Alcam, Mcam, and Ocam are expressed by a subset of motor neurons in the ventral spinal cord. Further analyses show that Ocam is expressed by obturator but not quadriceps motor neurons, suggesting that Ocam may regulate sensory-motor specificity in these sensory-motor reflex arcs. Electrophysiological analysis shows no obvious defects in synaptic specificity of monosynaptic sensory-motor connections involving obturator and quadriceps motor neurons in Ocam mutant mice. Since a subset of Ocam+ motor neurons also express Alcam, Alcam or other functionally redundant IgSF molecules may compensate for Ocam in controlling sensory-motor specificity. Taken together, these results reveal that IgSF molecules are broadly expressed by sensory and motor neurons during development, and that Ocam and other IgSF molecules may have redundant functions in controlling the specificity of sensory-motor circuits.

  6. Morphological characterization of spinal cord dorsal horn lamina I neurons projecting to the parabrachial nucleus in the rat.

    Science.gov (United States)

    Almarestani, L; Waters, S M; Krause, J E; Bennett, G J; Ribeiro-da-Silva, A

    2007-09-20

    Many Rexed's lamina I neurons are nociceptive and project to the brain. Lamina I projection neurons can be classified as multipolar, fusiform, or pyramidal, based on cell body shape and characteristics of their proximal dendrites in the horizontal plane. There is also evidence that both multipolar and fusiform cells are nociceptive and pyramidal neurons nonnociceptive. In this investigation we identified which types of lamina I neurons belong to the spinoparabrachial tract in the rat and characterized them regarding the presence or absence of neurokinin-1 receptor (NK-1r) immunoreactivity. For this, cholera toxin subunit B (CTb), conjugated to a fluorescent marker was injected unilaterally into the parabrachial nucleus. Sections were additionally stained for the detection of NK-1r immunoreactivity and were examined using fluorescence and confocal microscopy. Serial confocal optical sections and 3D reconstructions were obtained for a considerable number of neurons per animal. Using immunofluorescence, we assessed the proportion of lamina I neurons belonging to the spinoparabrachial (SPB) tract and/or expressing NK-1r. The relative distribution of neurons belonging to the SPB tract was: 38.7% multipolar, 36.8% fusiform, 22.7% pyramidal, and 1.9% unclassified. Most of the SPB neurons expressing NK-1r were either multipolar or fusiform. Pyramidal SPB neurons were seldom immunoreactive for NK-1r, an observation that provides further support to the concept that most lamina I projection neurons of the pyramidal type are nonnociceptive. In addition, our study provides further evidence that these distinct morphological types of neurons differ in their phenotypic properties, but not in their projection patterns.

  7. Dorsal border periaqueductal gray neurons project to the area directly adjacent to the central canal ependyma of the C4-T8 spinal cord in the cat

    NARCIS (Netherlands)

    Mouton, LJ; Kerstens, L; VanderWant, J; Holstege, G

    1996-01-01

    In a previous study horseradish peroxidase (HRP) injections in the upper thoracic and cervical spinal cord revealed some faintly labeled small neurons at the dorsal border of the periaqueductal gray (PAG). The present light microscopic and electronmicroscopic tracing study describes the precise loca

  8. 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.

  9. Idiopathic spinal cord herniation with duplicated dura mater and dorsal subarachnoid septum. Report of a case and review of the literature

    Science.gov (United States)

    Yamamoto, Norio; Higashino, Kousaku; Sairyo, Koichi

    2014-01-01

    Background Idiopathic spinal cord herniation (ISCH) is a rare condition and its pathogenesis remains unclear. The purpose of this case report is to present an ISCH case with dorsal subarachnoid septum suggesting the pathogenesis of ISCH being adhesions from preexisting inflammation. Methods Single case report. Results A 60-year-old woman presented with Brown-Séquard syndrome below the level of T6. Magnetic resonance imaging revealed the thoracic spinal cord was displaced ventrally, and the dorsal subarachnoid space was enlarged and had a septum between the spinal cord and dura mater. Intraoperatively, the dorsal dura mater was seen to be adherent and the subarachnoid septum was identified after durotomy. The inner layer defect of the duplicated dura mater was found in the ventral dura mater, through which the spinal cord had herniated. After releasing the septum, the adhesions around the dura mater, and the hiatus, the spinal cord was reduced. Conclusions The present case indicates that adhesions around the dura mater can be the pathogenesis of ISCH. PMID:25694934

  10. Differential effects of glutamate receptor antagonists on dorsal horn neurons responding to colorectal distension in a neonatal colon irritation rat model

    Institute of Scientific and Technical Information of China (English)

    Chun Lin; Elie D Al-Chaer

    2005-01-01

    AIM: To investigate and compare the effects of spinal D-(-)-2-amino-7-phosphonoheptanoic acid (AP-7) and 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX),two glutamate receptor antagonists, on the responses of dorsal horn neurons to colorectal distension (CRD) in adult rats exposed to neonatal colon irritation (CI).METHODS: Hypersensitive SD rats were generated by CI during postnatal days 8, 10 and 12. Experiments on adult rats were performed using extracellular single-unit recording. The effects of spinal application of AP-7 (0.001,0.01, 0.1, 1 mmoL) were tested on the CRD-evoked neuronal responses in 16 controls and 17 CI rats. The effects of CNQX (0.2, 2, 5, 10 μmoL) were also tested on the CRD-evoked responses of 17 controls and 18 CI neurons.RESULTS: (1) The average responses of lumbosacral neurons to all intensities of CRD in CI rats were significantly higher than those in control rats; (2) In control rats, AP-7 (0.01 mmoL) had no significant effect on the neuronal response to all intensities of CRD (20,40, 60, 80 mmHg); while AP-7 (0.1 mmoL) inhibited the neuronal response to 80-mmHg CRD. By contrast, in CI rats, AP-7 (0.01-1 mmoL) attenuated the CRD-evoked neuronal responses to all distention pressures in a dosedependent manner; (3) In control rats, CNQX (2 μmoL)had no significantly effect on the neuronal response to all intensities of CRD; however, CNQX (5 μmoL) significantly attenuated the responses to CRD in the 40-80 mmHg range. By contrast, CNQX (2-10 μmoL)significantly decreased the neuronal responses in CI rats to non-noxious and noxious CRD in a dose-dependent manner.CONCLUSION: Our results suggest that spinal N-methyl-D-aspartate (NMDA) and non-NMDA receptors may contribute to the processing of central sensitivity in a neonatal CI rat model, but they may play different roles in it.

  11. Neurokinin-1 Receptor-Immunopositive Neurons in the Medullary Dorsal Horn Provide Collateral Axons to both the Thalamus and Parabrachial Nucleus in Rats.

    Science.gov (United States)

    Li, Xu; Ge, Shun-Nan; Li, Yang; Wang, Han-Tao

    2017-01-17

    It has been suggested that the trigemino-thalamic and trigemino-parabrachial projection neurons in the medullary dorsal horn (MDH) are highly implicated in the sensory-discriminative and emotional/affective aspects of orofacial pain, respectively. In previous studies, some neurons were reported to send projections to both the thalamus and parabrachial nucleus by way of collaterals in the MDH. However, little is known about the chemoarchitecture of this group of neurons. Thus, in the present study, we determined whether the neurokinin-1 (NK-1) receptor, which is crucial for primary orofacial pain signaling, was expressed in MDH neurons co-innervating the thalamus and parabrachial nucleus. Vesicular glutamate transporter 2 (VGLUT2) mRNA, a biomarker for the subgroup of glutamatergic neurons closely related to pain sensation, was assessed in trigemino-parabrachial projection neurons in the MDH. After stereotactic injection of fluorogold (FG) and cholera toxin subunit B (CTB) into the ventral posteromedial thalamic nucleus (VPM) and parabrachial nucleus (PBN), respectively, triple labeling with fluorescence dyes for FG, CTB and NK-1 receptor (NK-1R) revealed that approximately 76 % of the total FG/CTB dually labeled neurons were detected as NK-1R-immunopositive, and more than 94 % of the triple-labeled neurons were distributed in lamina I. In addition, by FG retrograde tract-tracing combined with fluorescence in situ hybridization (FISH) for VGLUT2 mRNA, 54, 48 and 70 % of FG-labeled neurons in laminae I, II and III, respectively, of the MDH co-expressed FG and VGLUT2 mRNA. Thus, most of the MDH neurons co-innervating the thalamus and PBN were glutamatergic. Most MDH neurons providing the collateral axons to both the thalamus and parabrachial nucleus in rats were NK-1R-immunopositive and expressed VGLUT2 mRNA. NK-1R and VGLUT2 in MDH neurons may be involved in both sensory-discriminative and emotional/affective aspects of orofacial pain processing.

  12. 毒蕈碱乙酰胆碱M2/M4受体亚型在调节脊髓背角神经元谷氨酸能递质释放中的作用%Role of muscarinic cholinergic receptor subtypes in regulating glutamatergic synaptic transmission in rat spinal dorsal horn

    Institute of Scientific and Technical Information of China (English)

    杜威; 郭英; 袁维秀

    2013-01-01

    Objective To investigate the role of muscarinic cholinergic receptor (mAChR) subtypes in the regulation of glutamatergic input to the spinal dorsal horn neurons and the possible mechanism.Methods Whole-cell voltage-clamp recordings on acute spinal slice was utilized to investigate the effect of activation of mAChRs and blockade of M2/M4 subtypes on glutamatergic synaptic transmission in rat spinal dorsal horn neurons.Results The nonselective mAChRs agonist oxotremorine-M concentration-dependently decreased the amplitude of monosynaptic and polysynaptic evoked glutamate-mediated excitatory postsynaptic currents (eEPSCs) in most of the neurons.The M2/M4 antagonist himbacine completely blocked the inhibitory effect of oxotremorine-M in 92.3% of monosynaptic and 75% of polysynaptic neurons in the spinal cord slices.In the remaining 16% neurons,himbacine partially blocked the inhibitory effect of oxotremorine-M.Conclusions Activation of mAChRs in the spinal cord attenuates synaptic glutamate release to the dorsal horn neurons mainly through M2 and M4 receptor subtypes,indicating that a presynaptic inhibition in the spinal cord may be involved in the regulation of nociception by the cholinergic system and mAChRs.%目的 研究毒蕈碱胆碱能受体(mAChRs)亚型对脊髓背角感觉神经元谷氨酸能突触传递的调节机制.方法 在急性切取的腰段脊髓切片上,利用全细胞膜片钳法记录mAChRs非特异性激动剂氢化震颤素M(Oxo-M)对脊髓背角浅层神经元谷氨酸能兴奋性突触后电流(eEPSCs)的影响,给予M2/M4受体特异性拮抗剂喜巴辛,观察mAChRs在脊髓背角浅层神经元谷氨酸能递质释放调节过程中的作用.结果 不同浓度Oxo-M使脊髓背角神经元单突触和多突触eEPSCs的幅度显著降低,其抑制强度呈浓度依赖性,喜巴辛可以拮抗Oxo-M对刺激诱发eEPSCs幅度的抑制作用,在记录的25个细胞中,92.3%的单突触细胞和75%的多突触细胞表现为Oxo-M

  13. Inhibitory effects of CB1 and CB2 receptor agonists on responses of DRG neurons and dorsal horn neurons in neuropathic rats.

    Science.gov (United States)

    Sagar, Devi Rani; Kelly, Sara; Millns, Paul J; O'Shaughnessey, Celestine T; Kendall, David A; Chapman, Victoria

    2005-07-01

    Cannabinoid 2 (CB2) receptor mediated antinociception and increased levels of spinal CB2 receptor mRNA are reported in neuropathic Sprague-Dawley rats. The aim of this study was to provide functional evidence for a role of peripheral, vs. spinal, CB2 and cannabinoid 1 (CB1) receptors in neuropathic rats. Effects of the CB2 receptor agonist, JWH-133, and the CB1 receptor agonist, arachidonyl-2-chloroethylamide (ACEA), on primary afferent fibres were determined by calcium imaging studies of adult dorsal root ganglion (DRG) neurons taken from neuropathic and sham-operated rats. Capsaicin (100 nm) increased [Ca2+]i in DRG neurons from sham and neuropathic rats. JWH-133 (3 microm) or ACEA (1 microm) significantly (PCB2 receptor antagonist, SR144528, (1 microm) significantly inhibited the effects of JWH-133. Effects of ACEA were significantly inhibited by the CB1 receptor antagonist SR141716A (1 microm). In vivo experiments evaluated the effects of spinal administration of JWH-133 (8-486 ng/50 microL) and ACEA (0.005-500 ng/50 microL) on mechanically evoked responses of neuropathic and sham-operated rats. Spinal JWH-133 attenuated mechanically evoked responses of spinal neurons in neuropathic, but not sham-operated rats. These inhibitory effects were blocked by SR144528 (0.001 microg/50 microL). Spinal ACEA inhibited mechanically evoked responses of neuropathic and sham-operated rats, these effects were blocked by SR141716A (0.01 microg/50 microL). Our data provide evidence for a functional role of CB2, as well as CB1 receptors on DRG neurons in sham and neuropathic rats. At the level of the spinal cord, CB2 receptors have inhibitory effects in neuropathic, but not sham-operated rats suggesting that spinal CB2 may be an important analgesic target.

  14. Serotonin concentrations in the lumbosacral spinal cord of the adult rat following microinjection or dorsal surface application.

    Science.gov (United States)

    Brumley, Michele R; Hentall, Ian D; Pinzon, Alberto; Kadam, Brijesh H; Blythe, Anthony; Sanchez, Francisco J; Taberner, Annette M; Noga, Brian R

    2007-09-01

    Application of neuroactive substances, including monoamines, is common in studies examining the spinal mechanisms of sensation and behavior. However, affected regions and time courses of transmitter activity are uncertain. We measured the spatial and temporal distribution of serotonin [5-hydroxytryptamine (5-HT)] in the lumbosacral spinal cord of halothane-anesthetized adult rats, following its intraspinal microinjection or surface application. Carbon fiber microelectrodes (CFMEs) were positioned at various locations in the spinal cord and oxidation currents corresponding to extracellular 5-HT were measured by fast cyclic voltammetry. Intraspinal microinjection of 5-HT (100 microM, 1-3 microl) produced responses that were most pronounced at CFMEs positioned dorsal surface and <0.001% between 1,170 and 2,000 microm. This initial response to superfusion was sometimes followed by a gradual increase to a new concentration plateau. In sum, compared with bath application, microinjection can deliver about tenfold higher transmitter concentrations, but to much more restricted areas of the spinal cord.

  15. Regulation of neuropilin 1 by spinal cord injury in adult rats.

    Science.gov (United States)

    Agudo, Marta; Robinson, Michelle; Cafferty, William; Bradbury, Elizabeth J; Kilkenny, Carol; Hunt, Stephen P; McMahon, Stephen B

    2005-03-01

    Using RT-PCR, in situ hybridization, Western blotting, and immunofluorescence, we have analyzed the expression of neuropilin 1 (Np1) in two models of spinal cord injury (spinal cord hemisection and dorsal column crush) and following dorsal root rhizotomy in adult rats. Our results show that Np1 RNA and protein are up-regulated in the spinal cord after all these lesions but remain unaltered in the adjacent dorsal root ganglia. In control animals, Np1 levels in the spinal cord are low and appear to be localized mainly in blood vessels, motoneurons, and in the superficial layers of the dorsal horn. After DCC and rhizotomy, Np1 is expressed de novo around the injury and in the deafferentated dorsal horn, respectively, mainly by OX42-positive microglial cells. Both lesions affect the sensory projections, and interestingly a consistent increase of Np1 signal is additionally seen in the dorsal horn where these projections terminate. Unexpectedly, this increase is bilateral after unilateral rhizotomy.

  16. Treating Chronic Pain after Spinal Cord Injury

    Science.gov (United States)

    2016-09-01

    5   Our preliminary data indicated that severe SCI rats exhibited cold allodynia. During this cycle we confirmed and expanded our studies. We...reflecting expanded nociceptive inputs to dorsal horn neurons [17; 20; 54]. However, in contrast to SCI of moderate severity, we did not observe changes in...traumatic injuries, including spinal cord injury ( SCI ). Chronic pain so greatly affects quality of life that depression and suicide frequently result

  17. 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, ZnSe...

  18. Cervical dorsal rhizotomy increases brain-derived neurotrophic factor and neurotrophin-3 expression in the ventral spinal cord.

    Science.gov (United States)

    Johnson, R A; Okragly, A J; Haak-Frendscho, M; Mitchell, G S

    2000-05-15

    Although neurotrophic factors have been implicated in several forms of neuroplasticity, little is known concerning their potential role in spinal plasticity. Cervical dorsal rhizotomy (CDR) enhances serotonin terminal density near (spinal) phrenic motoneurons and serotonin-dependent long-term facilitation of phrenic motor output (Kinkead et al., 1998). We tested the hypothesis that selected neurotrophic factors change in a manner consistent with an involvement in this model of spinal plasticity. Brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), glial cell line-derived neurotrophic factor (GDNF), and transforming growth factor-beta(1) (TGF-beta(1)) concentrations were measured (ELISA) in three regions of interest to respiratory control: (1) ventral cervical spinal segments associated with the phrenic motor nucleus (C3-C6), (2) ventral thoracic spinal segments associated with inspiratory intercostal motor output (T3-T6) and (3) the diaphragm. Tissues were harvested from rats 7 d after bilateral CDR and compared with sham-operated and unoperated control rats. CDR increased BDNF (110%; p = 0.002) and NT-3 (100%; p = 0.002) in the cervical and NT-3 in the thoracic spinal cord (98%; p = 0.009). GDNF and TGF-beta(1) were not altered by CDR in any tissue. Immunohistochemistry localized BDNF and NT-3 to motoneurons and interneurons of the ventral spinal cord. These studies provide novel, suggestive evidence that BDNF and NT-3, possibly through their trophic effects on serotonergic neurons and/or motoneurons, may underlie serotonin-dependent plasticity in (spinal) respiratory motor control after CDR.

  19. Neurotrophin-3-mediated regeneration and recovery of proprioception following dorsal rhizotomy.

    Science.gov (United States)

    Ramer, Matt S; Bishop, Thomas; Dockery, Peter; Mobarak, Makarim S; O'Leary, Donald; Fraher, John P; Priestley, John V; McMahon, Stephen B

    2002-02-01

    Injured dorsal root axons fail to regenerate into the adult spinal cord, leading to permanent sensory loss. We investigated the ability of intrathecal neurotrophin-3 (NT3) to promote axonal regeneration across the dorsal root entry zone (DREZ) and functional recovery in adult rats. Quantitative electron microscopy showed robust penetration of CNS tissue by regenerating sensory axons treated with NT3 at 1 and 2 weeks postrhizotomy. Light and electron microscopical anterograde tracing experiments showed that these axons reentered appropriate and ectopic laminae of the dorsal horn, where they formed vesicle-filled synaptic buttons. Cord dorsum potential recordings confirmed that these were functional. In behavioral studies, NT3-treated (but not untreated or vehicle-treated) rats regained proprioception. Recovery depended on NT3-mediated sensory regeneration: preventing regeneration by root excision prevented recovery. NT3 treatment allows sensory axons to overcome inhibition present at the DREZ and may thus serve to promote functional recovery following dorsal root avulsions in humans.

  20. Effect of FGF-2 and sciatic nerve grafting on ChAT expression in dorsal root ganglia neurons of spinal cord transected rats.

    Science.gov (United States)

    Guzen, Fausto Pierdoná; de Araújo, Dayane Pessoa; Lucena, Eudes Euler de Souza; de Morais, Hécio Henrique Araújo; Cavalcanti, José Rodolfo Lopes de Paiva; do Nascimento, Expedito Silva; Costa, Miriam Stela Maris de Oliveira; Cavalcante, Jeferson Sousa

    2016-03-11

    Neurotrophic factors and peripheral nerves are known to be good substrates for bridging CNS trauma. The involvement of fibroblast growth factor-2 (FGF-2) activation in the dorsal root ganglion (DRG) was examined following spinal cord injury in the rat. We evaluated whether FGF-2 increases the ability of a sciatic nerve graft to enhance neuronal plasticity, in a gap promoted by complete transection of the spinal cord. The rats were subjected to a 4mm-long gap at low thoracic level and were repaired with saline (Saline or control group, n=10), or fragment of the sciatic nerve (Nerve group, n=10), or fragment of the sciatic nerve to which FGF-2 (Nerve+FGF-2 group, n=10) had been added immediately after lesion. The effects of the FGF-2 and fragment of the sciatic nerve grafts on neuronal plasticity were investigated using choline acetyl transferase (ChAT)-immunoreactivity of neurons in the dorsal root ganglion after 8 weeks. Preservation of the area and diameter of neuronal cell bodies in dorsal root ganglion (DRG) was seen in animals treated with the sciatic nerve, an effect enhanced by the addition of FGF-2. Thus, the addition of exogenous FGF-2 to a sciatic nerve fragment grafted in a gap of the rat spinal cord submitted to complete transection was able to improve neuroprotection in the DRG. The results emphasized that the manipulation of the microenvironment in the wound might amplify the regenerative capacity of peripheral neurons.

  1. Nestin-positive cells in the spinal cord: a potential source of neural stem cells.

    Science.gov (United States)

    Xu, Renshi; Wu, Chengsi; Tao, Yuhui; Yi, Juan; Yang, Yunzhu; Zhang, Xiong; Liu, Rugao

    2008-11-01

    Some literatures have reported neural precursor cells (NPCs) exist in spinal cord of adult mammal, however, the NPCs distribution feature in spinal cord of adult mice so far is not described in detail. In order to observe and compare the distribution feature of NPCs in various spinal cord regions of adult mice, to research a potential source of neural stem cells (NSCs), we obtained NPCs distribution feature by analyzing the distribution of the nestin-containing cells (NCCs) in spinal cord of adult nestin second-intron enhancer controlled LacZ reporter transgenic mice (pNes-Tg) with LacZ staining and positive cell quantification. The results showed that: NCCs were observed in various regions of spinal cord of adult mice, but amount of NCCs was different in distinct region, the rank order of NCCs amount in various spinal cord regions was dorsal horn region greater than central canal greater than the ventral and lateral horn. NCCs in dorsal horn region mainly distributed in substantia gelatinosa, NCCs in central canal mainly distributed in ependymal zone, on the contrary, NCCs in ventral, lateral horn, medullae, nucleus regions of spinal cord were comparatively less. The rank order of NCCs amount in various spinal cord segments was cervical segment greater than lumbar sacral segment greater than thoracic segment. There was no significantly difference between NCCs amount in the left and right sides, and within cervical 1-7, thoracic 1-12, lumbar 1-5, sacral segment of spinal cord in adult mice. These data collectively indicate that NPCs extensively distribute in various regions of spinal cord of adult mice, especially in substantia gelatinosa and ependymal zone. NPCs in cervical segment are abundant, NPCs in thoracic segment are the least while compared the different spinal cord segment, the NPCs in various regions of spinal cord of adult mice are a potential source of NSCs.

  2. 不同频率电针对正常大鼠脊髓背角的转录组学研究%Transcriptomics Study of the Transcriptional Response of the Spinal Dorsal Horn to Electroacupuncture Stimulation with Different Frequencies

    Institute of Scientific and Technical Information of China (English)

    王珂; 张嵘; 赵国屏; 张庆华; 崔彩莲

    2012-01-01

    Objective To explore the effects of low-and high-frequency electroacupuncture (EA) on the gene expression profiles in rat spinal dorsal horn (DH) under the physiological state, thus providing the information to find out the differences of different EA frequencies induced effects. Methods Using cDNA microarray, the changes of the gene expressions in the DH were detected and compared between 2 Hz EA and 100 Hz EA at bilateral Zusanli (ST36) and Sanyinjiao(SP6). The differentially expressed genes were identified. The EASE scores were used to comprehensively analyze the gene functions (by Gene Ontology) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Results (1) After EA stimulation 1 150 genes/expressed sequence tags (ESTs) were differentially expressed by 2 Hz EA, while 1 270 genes/ESTs were differentially expressed by 100 Hz EA. (2) Both 2 Hz and 100 Hz EA could induce the modulation of the same 516 genes/ESTs in the same direction, which was correlated with neural signal transmission. (3) The differentially expressed genes regulated specifically by 2 Hz were correlated with neural plasticity. (4) The differentially expressed genes regulated specifically by 100 Hz were correlated with stress and immunoregulation. Conclusions Either low-or high-frequency EA could extensively regulate the spinal cord information processing. The low-frequency EA participated more in the regulation of neural plasticity, while high-frequency EA had more significant effects on stress and immunoregulation.%目的 探索生理状态下低频和高频电针对大鼠脊髓背角区域基因表达谱的影响,为理解不同频率的电针效应差异提供研究资料.方法 采用基因表达谱芯片技术,检测比较2 Hz和100 Hz电针刺激大鼠双侧足三里穴(ST36)和三阴交穴(SP6)后脊髓背角区域基因表达的变化,识别差异表达基因,利用生物信息学手段对差异表达基因所涉及的基因功能和通路进行富集识别与分析.结果 (1

  3. Distribution of serotonin 2A and 2C receptor mRNA expression in the cervical ventral horn and phrenic motoneurons following spinal cord hemisection.

    Science.gov (United States)

    Basura, G J; Zhou, S Y; Walker, P D; Goshgarian, H G

    2001-06-01

    Cervical spinal cord injury leads to a disruption of bulbospinal innervation from medullary respiratory centers to phrenic motoneurons. Animal models utilizing cervical hemisection result in inhibition of ipsilateral phrenic nerve activity, leading to paralysis of the hemidiaphragm. We have previously demonstrated a role for serotonin (5-HT) as one potential modulator of respiratory recovery following cervical hemisection, a mechanism that likely occurs via 5-HT2A and/or 5-HT2C receptors. The present study was designed to specifically examine if 5-HT2A and/or 5-HT2C receptors are colocalized with phrenic motoneurons in both intact and spinal-hemisected rats. Adult female rats (250-350 g; n = 6 per group) received a left cervical (C2) hemisection and were injected with the fluorescent retrograde neuronal tracer Fluorogold into the left hemidiaphragm. Twenty-four hours later, animals were killed and spinal cords processed for in situ hybridization and immunohistochemistry. Using (35)S-labeled cRNA probes, cervical spinal cords were probed for 5-HT2A and 5-HT2C receptor mRNA expression and double-labeled using an antibody to Fluorogold to detect phrenic motoneurons. Expression of both 5-HT2A and 5-HT2C receptor mRNA was detected in motoneurons of the cervical ventral horn. Despite positive expression of both 5-HT2A and 5-HT2C receptor mRNA-hybridization signal over phrenic motoneurons, only 5-HT2A silver grains achieved a signal-to-noise ratio representative of colocalization. 5-HT2A mRNA levels in identified phrenic motoneurons were not significantly altered following cervical hemisection compared to sham-operated controls. Selective colocalization of 5-HT2A receptor mRNA with phrenic motoneurons may have implications for recently observed 5-HT2A receptor-mediated regulation of respiratory activity and/or recovery in both intact and injury-compromised states.

  4. Intravenous administration of lidocaine directly acts on spinal dorsal horn and produces analgesic effect: An in vivo patch-clamp analysis

    OpenAIRE

    Miyuki Kurabe; Hidemasa Furue; Tatsuro Kohno

    2016-01-01

    Intravenous lidocaine administration produces an analgesic effect in various pain states, such as neuropathic and acute pain, although the underlying mechanisms remains unclear. Here, we hypothesized that intravenous lidocaine acts on spinal cord neurons and induces analgesia in acute pain. We therefore examined the action of intravenous lidocaine in the spinal cord using the in vivo patch-clamp technique. We first investigated the effects of intravenous lidocaine using behavioural measures i...

  5. Astrocytes and Microglia-Mediated Immune Response in Maladaptive Plasticity is Differently Modulated by NGF in the Ventral Horn of the Spinal Cord Following Peripheral Nerve Injury.

    Science.gov (United States)

    De Luca, Ciro; Savarese, Leonilde; Colangelo, Anna Maria; Bianco, Maria Rosaria; Cirillo, Giovanni; Alberghina, Lilia; Papa, Michele

    2016-01-01

    Reactive astrocytes and activated microglia are the key players in several pathophysiologic modifications of the central nervous system. We used the spared nerve injury (SNI) of the sciatic nerve to induce glial maladaptive response in the ventral horn of lumbar spinal cord and examine its role in the remodeling of the tripartite synapse plasticity. Imaging the ventral horn revealed that SNI was associated with both an early microglial and astrocytic activation, assessed, respectively, by analysis of Iba1 and GFAP expression. Microglia, in particular, localized peculiarly surrounding the motor neurons somata. Perineuronal astrocytes, which play a key role in maintaining the homeostasis of neuronal circuitry, underwent a substantial phenotypic change following peripheral axotomy, producing reactive gliosis. The gliosis was associated with the reduction of glial aminoacid transporters (GLT1 and GlyT1) and increase of neuronal glutamate transporter EAAC1. Although the expression of GABAergic neuronal marker GAD65/67 showed no change, glutamate increase, as demonstrated by HPLC analysis, shifted the excitatory/inhibitory balance as showed by the net increase of the glutamate/GABA ratio. Moreover, endogenous NGF levels were altered in SNI animals and not restored by the intrathecal NGF administration. This treatment reverted phenotypic changes associated with reactive astrocytosis, but failed to modify microglia activation. These findings on one hand confirm the correlation between gliopathy and maladaptive plasticity of the spinal synaptic circuitry, on the other hand add new data concerning the complex peculiar behavior of different glial cells in neuronal degenerative processes, defining a special role of microglia in sustaining the inflammatory response.

  6. 姜黄素对2型糖尿病神经病理性痛大鼠脊髓背角及背根神经节p-ERK和p-CREB表达的影响%Effect of curcumin on expression of p-ERK and p-CREB in spinal dorsal horn and dorsal root ganglion in type 2 diabetic neuropathic pain in rats

    Institute of Scientific and Technical Information of China (English)

    周林; 袁超; 史小婷; 郑昌健; 连庆泉; 李军; 曹红

    2013-01-01

    fasting blood glucose level≥ 16.7 mmol/L in male Sprague-Dawley rats.Type 2 DNP was confirmed by the mechanical withdrawal threshold (MWT) and thermal withdraw latency (TWL) measured on day 14 after STZ administration < 80% of the baseline value,and the rats with type 2 DNP were randomly divided into 3 groups (n =27 each):type 2 DNP group (group DNP),curcumin group (group Cur) and solvent control group (group SC).Curcumin and corn oil 100 mg/kg (25 mg/ml) were injected intraperitoneally once a day for 14consecutive days starting from 14 days after administration of streptozocin in Cur and SC groups,respectively.Another 27 normal rats were served as control group (group C) and were fed with common forage.MWT and TWL were measured at 3,7 and 14 days after curcumin injection (T1 3),and the lumbar segment 4-6 of the spinal cord and DRGs were removed at the same time for determination of the expression of p-ERK and p-CREB (by Western blot).Results Compared with group C,MWT was significantly decreased,TWL was shortened,and the expression of p-ERK and p-CREB in spinal dorsal horn and DRGs was up-regulated at T1-3 in DNP and SC groups,and at T1 in Cur group (P < 0.05).Compared with group DNP,MWT was significantly increased,TWL was prolonged,and the expression of p-ERK and p-CREB in spinal dorsal horn and DRGs was down-regulated at T2,3 in Cur group (P <0.05).There was no significant difference in the MWT,TWL and expression of p-ERK and p-CREB between DNP and SC groups (P > 0.05).Conclusion Curcumin can attenuate type 2 diabetic DNP by inhibiting up-regulation of the expression of p-ERK and p-CREB in the spinal dorsal horn and DRG in rats.

  7. 姜黄素对2型糖尿病神经病理性痛大鼠脊髓背角和背根神经节MMP-2及MMP-9表达的影响%Effect of curcumin on expression of MMP-2 and MMP-9 in spinal dorsal horn and dorsal root ganglion of rats with type 2 diabetic neuropathic pain

    Institute of Scientific and Technical Information of China (English)

    吴绍胜; 孙传峰; 曹红; 李佳佳; 史小婷; 李军

    2014-01-01

    Objective To evaluate the effect of curcumin on the expression of MMP-2 and MMP-9 in the spinal dorsal horn and dorsal root ganglion (DRG) of rats with type 2 diabetic neuropathic pain (DNP).Methods Type 2 diabetes mellitus was induced by high-fat and high-sucrose diet and intraperitoneal streptozotocin 35 mg/kg,and confirmed by fasting blood glucose level ≥ 16.7 mmol/L in male Sprague-Dawley rats.Type 2 DNP was confirmed by the mechanical paw withdrawal threshold (MWT) and thermal paw withdraw latency (TWL) measured on day 14 after streptozotocin administration < 80% of the baseline value.The rats were then randomly divided into 3 groups (n =27 each):type 2 DNP group (group DNP); curcumin group (group Cur); solvent control group (group SC).In Cur and SC groups,curcumin 100 mg/kg and corn oil 4 ml/kg were injected intraperitonally,respectively,once a day for 14 consecutive days starting from day 14 after streptozotocin administration.Another 27 normal Sprague-Dawley male rats served as control group (group C) and were fed with normal forage.MWT and TWL were measured before type 2 DNP was induced,after type 2 DNP was induced,and at 3,7 and 14 days after curcumin injection(T1-5).The rats were sacrificed after MWT and TWL were measured at T3-5,and the lumbar segments of the spinal cord and DRG (L4-6) were removed for determination of the expression of MMP-2 and MMP-9 by Western blot.Results Compared with group C,MWT was significantly decreased and TWL was shortened,and MMP-2 and MMP-9 expression in the spinal dorsal horn and DRG was up-regulated in DNP,Cur and SC groups.Compared with DNP group,MWT was significantly increased and TWL was prolonged,and MMP-2 and MMP-9 expression in the spinal dorsal horn and DRG was down-regulated in Cur group,and no significant changes were found in the parameters mentioned above in SC group.Conclusion The mechanism by which curcumin attenuates type 2 DNP may be related to up-regulation of the expression of MMP-2 and MMP-9 in the

  8. Expression of GABAB1 receptors in spinal dorsal horn neurons in rats with diabetic neuropathic pain%糖尿病神经病理性痛大鼠脊髓背角γ-氨基丁酸B1受体表达的变化

    Institute of Scientific and Technical Information of China (English)

    刘彦涛; 王秀丽; 王倩; 董蕊; 马江红; 王秋筠; 郭跃先

    2010-01-01

    Objective To investigate the role of GABAB1 receptors in spinal dorsal horn neurons in the development of diabetic neuropathic pain (DNP). Methods Sixty pathogen free male SD rats aged 4 weeks weighing 150-170 g were randomly divided into 2 groups ( n = 30 each): control group and DNP group. Diabetes mellitus was induced by single intraperitoneal injection of streptozotocin 50 mg/kg. Blood glucose levels and paw withdrawal threshold to mechanical stimuli were measured at 3, 5 and 7 weeks (T1, T2, T3 ) after IP STZ/NS ( n = 10 each). The animals were sacrificed after PWL measurement. The lumbar segment of the spinal cord was removed for determination of the expression of GABAB1 receptors by immuno-histochemistry, RT-PCR and Western blot analysis. Results The blood glucose levels were significantly higher while the PWT was significantly lower at T1,T2 and T3 in group DNP than in control group. The expression of GABAB1 receptor mRNA and protein in spinal dorsal horn was significantly lower at T2 and T3 in DNP group than in control group. Conclusion The expression of GABAb1 receptors is down-regulated in spinal dorsal horn neurons in rats with DNP.%目的 探讨糖尿病神经病理性痛(DNP)大鼠脊髓背角γ-氨基丁酸B1(GABAB1)受体表达的变化.方法 SD雄性大鼠60只,随机分为2组(n=30),DNP组(D组)腹腔注射链脲佐菌素50 mg/kg制备糖尿病模型,正常对照组(C组)给予等容量生理盐水.分别于给予链脲佐菌素或生理盐水后3、5、7周时取10只大鼠,采集静脉血样,测定空腹血糖浓度,然后测定机械缩足阈值,取脊髓组织,分别采用免疫组化法和Western blot法测定脊髓背角GABAB1受体表达水平,采用RT-PCR法测定脊髓背角GABAB1受体mRNA表达水平.结果 与C组比较,D组血糖升高,机械缩足阈值降低,GABAB1受体及GABAB1受体mRNA表达下调(P<0.05).结论 DNP大鼠脊髓背角GABAB1受体表达下调.

  9. Acute effect of electrical stimulation of the dorsal genital nerve on rectal capacity in patients with spinal cord injury.

    Science.gov (United States)

    Worsøe, J; Fynne, L; Laurberg, S; Krogh, K; Rijkhoff, N J M

    2012-06-01

    Constipation and fecal incontinence are considerable problems for most individuals with spinal cord injury (SCI). Neurogenic bowel symptoms are caused by several factors including abnormal rectal wall properties. Stimulation of the dorsal genital nerve (DGN) can inhibit bladder contractions and because of common innervation inhibitory effects are anticipated in the rectum too. Therefore, DNG could have a future role in the treatment of neurogenic fecal incontinence. To study the effect of acute DGN stimulation on the rectal cross sectional area (CSA) in SCI patients. Seven patients with complete supraconal SCI (median age 50 years) were included. Stimulation was applied via plaster-electrodes using an amplitude of twice the genito-anal reflex threshold (pulse width: 200 μs; pulse rate: 20 Hz). A pressure controlled phasic (10, 20 and 30 cmH(2)O) rectal distension protocol was repeated four times with subjects randomized to stimulation during 1st and 3rd distension series or 2nd and 4th distension series. The rectal CSA and pressure were measured using impedance planimetry and manometry. All patients completed the investigation. Median stimulation amplitude was 51 mA (range 30-64). CSA was smaller during stimulation and differences reached statistical significance at distension pressures of 20 cmH(2)O (average decrease 9%; P = 0.02) and 30 cmH(2)O (average decrease 4%; P = 0.03) above resting rectal pressure. Accordingly, rectal pressure-CSA relation was significantly reduced during stimulation at 20 (P=0.03) and 30 cmH(2)O distension (P=0.02). DGN Stimulation in patients with supraconal SCI results in an acute decrease of rectal CSA and the rectal pressure-CSA relation.

  10. Presence of neuropeptide FF receptors on primary afferent fibres of the rat spinal cord

    Energy Technology Data Exchange (ETDEWEB)

    Zajac, J.-M. [Laboratoire de Pharmacologie et de Toxicologie Fondamentales, C.N.R.S., 205 Route de Narbonne, 31077 Toulouse Cedex (France); Kar, S. [Douglas Hospital Research Centre and Department of Psychiatry, McGill University, 6875 LaSalle Blvd, Verdun, Quebec H4H1R3 (Canada); Gouarderes, C. [Laboratoire de Pharmacologie et de Toxicologie Fondamentales, C.N.R.S., 205 Route de Narbonne, 31077 Toulouse Cedex (France)

    1996-09-01

    A radioiodinated analogue of neuropeptide FF, [{sup 125}I][d.Tyr{sup 1},(NMe)Phe{sup 3}]neuropeptide FF, was used as a selective probe to label neuropeptide FF receptors in the rat spinal cord. Following neonatal capsaicin treatment, dorsal rhizotomy or sciatic nerve section, the distribution and possible alterations of spinal cord specific [{sup 125}I][d.Tyr{sup 1},(NMe)Phe{sup 3}]neuropeptide FF binding sites were evaluated using in vitro quantitative receptor autoradiography. In normal rats, the highest densities of sites were observed in the superficial layers of the dorsal horn (laminae I-II) whereas moderate to low amounts of labelling were seen in the deeper (III-VI) laminae, around the central canal, and in the ventral horn. Capsaicin-treated rats showed a bilateral decrease (47%) in [{sup 125}I][d.Tyr{sup 1},(NMe)Phe{sup 3}]neuropeptide FF binding in all spinal areas. Unilateral sciatic nerve section and unilateral dorsal rhizotomy induced significant depletions (15-27%) in [{sup 125}I][d.Tyr{sup 1},(NMe)Phe{sup 3}]neuropeptide FF labelling in the ipsilateral dorsal horn.These results suggest that a proportion of neuropeptide FF receptors is located on primary afferent terminals of the dorsal horn and could thus play a role in the modulation of nociceptive transmission. (Copyright (c) 1996 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. 三种新发现的脊髓背角双投射神经元的特征与意义%Characteristics and implications of the three newly discovered double projection spinal dorsal horn neurons

    Institute of Scientific and Technical Information of China (English)

    吕国蔚; 李菁锦

    2002-01-01

    1980年来,我室用解剖学和(或)生理学方法鉴定出了脊颈束/背索突触后(sCT/DCPS),脊孤束/背索突触后(SST/DCPS)和脊颈束/脊孤束(SCT/SST)等三种脊髓背角神经元.这些神经元以经其各自的分叉轴突分别向两个靶核投射为特征.它们的另一特征是具有会聚性躯体-内脏觉传入输入.部分神经元除通过分叉初级传入从外周接受躯体-内脏感觉输入外,还从中枢神经系统各自的靶核接受躯体-内脏觉输入.这些发现对牵涉痛和针刺镇痛的发生机制提供新的理解.%Three neuronal populations, spinocervical tract / dorsal column postsynaptic (SCT/DCPS) , spinosolitarytract / dorsal column postsynaptic (SST/DCPS) and spinocervical tract / spinosolitary tract (SCT/SST) neurons, havebeen anatomically and/or physiologically identified in the spinal dorsal horn by our group since the 1980s. These newlyidentified neurons are characterized by their divergent projections to two target nuclei via their branched axons. These neu-rons are also characterized by having convergent viscero-somatic afferent inputs. Some of these neurons receive viscero-so-matic sensory inputs from both. the periphery via, in part, dichotomized primary afferents and their own target nuclei in thecentral nervous system. These findings put an new insight into mechanisms of referred pain and acupuncture.

  12. The effects of gallamine on field and dorsal root potentials produced by antidromic stimulation of motor fibres in the frog spinal cord.

    Science.gov (United States)

    Galindo, J; Rudomin, P

    1978-05-12

    The effects of gallamine on the intraspinal field potentials and the dorsal root potentials produced by antidromic stimulation of motor fibres were studied in the isolated frog spinal cord preparation. After gallamine (10-(3) M), the duration of the negative field potential produced by antidromic activation of motoneurons (N1 response) was increased often without changing its amplitude. This resulted in an increased passive spread of the antidromic action potential towards the dorsal dendritic regions, where afferent fibres terminate. In the untreated spinal cord, stimulation of motor axons produced a late negative dorsal root potential (VR-DRP) which was depressed after gallamine administration. Abolition of the VR-DRP was frequently associated with the appearance of a short latency, conducted response, in the dorsal roots (EVR-DRP). The earliest component of the EVR-DRP had a latency ranging between 0.5 and 2.5 ms measured after the peak of the N1 response recorded at the motor nucleus. Such a brief latency of the EVR-DRP suggests that this response results from electrical interaction between motoneurons and afferent fibres. After gallamine, the primary afferent depolarization produced by orthodromic stimulation of sensory nerves facilitates the EVR-DRP without necessarily increasing the amplitude or duration of the N1 response. Also, gallamine appears to increase directly the excitability of the afferent fibre terminal arborizations. The nature of the electrical interaction between motoneuron dendrites and afferent fibre terminal arborizations is discussed in terms of two hypotheses: interaction by current flows and by electrical coupling.

  13. The role of α1 adrenaline receptors on GABAergic and glutamatergic synapse in spinal dorsal horn%α1-肾上腺素受体参与调控脊髓背角神经元突触传递的作用机制

    Institute of Scientific and Technical Information of China (English)

    袁维秀; 郭英; 徐娟; 张宏

    2012-01-01

    Objective To investigate the role of α1-adrenaline receptors in GABAergic and glutamatergic synapses via GABAA receptors in spinal dorsal horn. Methods Using whole -cell voltage-clamp recordings on acute spinal cord slice, the effect of blockade of α1-adrenaline receptors on GABAergic and glutamatergic synaptic transmission was studied. Results Selective al -adrenline receptors agonist phenylephrine cold significantly increase the frequency of GABAergic spontaneous IPSCs in a concentration dependent manner, and this effect was abolished by the α1-adrenaline receptor antagonist WB4101. Phenylephrine also significantly reduced the amplitude of monosynaptic and polysynaptic EPSCs evoked from primary afferents. The inhibitory effect of phenylephrine on evoked monosynaptic glutamatergic EPSCs was largely blocked by the GABAA receptor antagonist picrotoxin. Conclusion Activation of α1- adrenoceptors in the spinal cord attenuates glutamatergic input from primary afferents mainly through GABAA receptors, indicating that presynaptic inhibition in the spinal cord may be involved in the regulation of nociception by the descending noradrenergic system.%目的 研究α1-肾上腺素受体(α1- AR)调控脊髓背角感觉神经元谷氨酸能突触传递的作用机制.方法 在急性切取的腰段脊髓切片上,利用全细胞膜片钳法记录α1- AR激动剂苯肾上腺素对脊髓背角浅层神经元抑制性和兴奋性突触后电流(IPSCs和eEPSCs)的影响.结果 苯肾上腺素对IPSCs频率产生剂量依赖性兴奋作用,此作用可被α1- AR特异性拮抗剂WB4101完全拮抗.苯肾上腺素对eEPSCs振幅的抑制作用可以部分被GABAA受体拮抗剂印防己毒素(picrotoxin,PTX)拮抗.结论 位于脊髓背角神经元的α1-AR,促进初级传入纤维在脊髓背角释放γ-氨基丁酸(GABA),进而主要通过GABAA受体抑制初级传入纤维兴奋性谷氨酸能神经冲动的传入.下行肾上腺素能系统可能通过GABAA受体机制参

  14. [Effects of electroacupuncture on glutamate and aspartic acid contents in the dorsal root ganglion and spinal cord in rats with neuropathic pain].

    Science.gov (United States)

    Ma, Cheng; Li, Cui-xian; Yi, Jian-liang; Yan, Li-ping

    2008-08-01

    To observe the effect of electroacupuncture (EA) on pain threshold and contents of excitatory amino acids (EAA) in dorsal root ganglia (DRG) and spinal cord in rats with neuropathic pain. Fifty SD rats were randomly divided into control (C),model (M), sham-model (SM), EA, and sham-EA groups, with 10 cases in each. Neuropathic pain (spared nerve injury, SNI) model was established by cutting off the right common peroneal nerve and proso-tibial nerve (with the sural nerve reserved intact). Before and after surgery, the mechanical pain threshold (MPT) and thermal pain threshold (TPT) were measured respectively on the injured side under consciousness state. EA (2 Hz, 1-3 mA, adding 1 mA/10 min) was applied to "Huantiao" (GB 30) and "Weizhong" (BL 40) on the affected side for 30 min. For rats of sham-EA group, filiform needles were inserted into GB30 and BL40 simply without manipulation or electrical stimulation. The treatment was given once daily for 7 days. On the 15th day, the rats were sacrificed for sampling right L4-L6 DRG and spinal cord. The contents of neurotransmitters, glutamate (Glu) and aspartic acid (Asp) in DRG and spinal cord were detected with high performance liquid chromatography (HPLC). Micro-dialysis technique was used to collect the dialysate from the spinal cord, homogenated for measuring EAA by HPLC. In comparison with control group, after SNI, MPT decreased significantly from the 1st day on in model group. Compared with model group, on the 15th day, MPT increased significantly in both EA and sham-EA groups (P 0.05). It suggested that sham EA still had an analgesic effect in spite of being lower than that of true EA. Compared with control group, the contents of Glu and Asp in the spinal cord tissue and micro-dialysate in model group increased significantly after SNI (P spinal cord tissue and micro-dialysate, and Asp in the spinal cord tissue and micro-dialysate in both sham-EA and EA groups decreased considerably (P spinal cord tissue Asp contents

  15. Projections from the paralemniscal nucleus to the spinal cord in the mouse.

    Science.gov (United States)

    Liang, Huazheng; Duan, Deyi; Watson, Charles; Paxinos, George

    2013-09-01

    The present study investigated the projection from the paralemniscal nucleus (PL) to the spinal cord in the mouse by injecting the retrograde tracer fluoro-gold to different levels of the spinal cord and injecting the anterograde tracer biotinylated dextran amine into PL. We found that PL projects to the entire spinal cord with obvious contralateral predominance--420 neurons projected to the contralateral cervical cord and 270 to the contralateral lumbar cord. Fibers from PL descended in the dorsolateral funiculus on the contralateral side and terminated in laminae 5, 6, 7, and to a lesser extent in the dorsal and ventral horns. A smaller number of fibers also descended in the ventral funiculus on the ipsilateral side and terminated in laminae 7, 8 and, to a lesser extent in lamina 9. The present study is the first demonstration of the PL fiber termination in the spinal cord in mammals. The PL projection to the spinal cord may be involved in vocalization and locomotion.

  16. 幻肢痛大鼠脊髓背角小胶质细胞和星形胶质细胞数量的变化%Changes in the number of microglias snd astrocytes in the spinal dorsal horn in a rat model of phantom limb pain

    Institute of Scientific and Technical Information of China (English)

    林菁艳; 彭彬; 杨正伟; 闵苏

    2012-01-01

    Objective To investigate the changes in the number of microglias and astrocytes in the spinal dorsal born in a rat model of phantom limb pain.Methods Eleven healthy adult SD rats of both sexes weighing 290-300 g were randomly divided into 2 groups:sham operation group (group S,n =5 ) and unilateral sciatic nerve transection group (group SNT,n =6).Phantom limb pain model was induced by resection of a 0.5 cm segment of unilateral sciatic nerve in group SNT.In group S unilateral sciatic nerve was exposed but not transected.The animals were observed for autotomy and scored (0 =no autotomy,13 =the worst autotomy) after operation and were sacrificed on the 28th day after operation.The L5 segment of the spinal cord was removed for determination of the number of microglials (by iba-1 immuno-histochemistry) and astrocytes (by GFAP immuno-histochemistry).Results In group S no animal developed autotomy.In group SNT autotomy started from the 2nd day after operation and the score reached 9-11.Compared with group S,the number of the microglias and astrocytes in the spinal dorsal horn was significantly decreased in the operated side in group SNT ( P < 0.05 ).Conclusion The number of microglias and astrocytes in the spinal dorsal horn is decreased in animals with phantom limb pain.%目的 探讨幻肢痛大鼠脊髓背角小胶质细胞和星形胶质细胞数量的变化.方法 健康成年SD大鼠11只,雌雄不拘,体重290~300 g,采用随机数字表法,将其随机分为2组:假手术组(S组,n=5)和单侧坐骨神经横断组(SNT组,n=6).术后持续观察SNT组大鼠自噬情况,并进行自噬评分.术后28d时取L5节段脊髓组织,分别进行iba-1(标记小胶质细胞)及胶质纤维酸性蛋白(标记星形胶质细胞)免疫组化染色,进行手术侧和非手术侧脊髓背角小胶质细胞和星形胶质细胞的计数.结果 S组无一只大鼠发生自噬,SNT组术后2d开始陆续发生自噬,最高自噬评分9~11分.与S组比较,SNT组手术侧脊

  17. Effects of intrathecal injection of glial cell inhibitor on spinal cord astrocytes following chronic compression of dorsal root ganglia in rats

    Institute of Scientific and Technical Information of China (English)

    Xianhong Zhang; Wen Shen; Mingde Wang; Yinming Zeng

    2009-01-01

    BACKGROUND: Astrocytes are considered to provide nutritional support in the central nervous system. However, recent studies have confirmed that astrocytes also play an important role in chronic pain. OBJECTIVE: To investigate the effects of intrathecal injection of fluorocitrate, minocycline or both on astrocyte activation and proliferation in the spinal dorsal horn of compressed dorsal root ganglion in rats. DESIGN, TIME AND SETTING: The neurology randomized controlled animal study was performed at the Jiangsu Institute of Anesthesia Medicine, from September 2006 to April 2007. MATERIALS: A total of 96 male Sprague Dawley rats, aged 6-8 weeks, were selected for this study. Following intrathecal catheterization, 80 rats underwent steel bar insertion into the L4-5 intervertebral foramina to make a stable compression on the L4-5 posterior root ganglion. Thus rat models of ganglion compression were established. Minocycline and fluorocitrate were purchased from Sigma, USA. METHODS: A total of 96 rats were randomly and equally divided into six groups. Rat L4, L5 transverse process and intervertebral foramina were exposed in the sham operation group, but without steel bar insertion. The model group did not receive any manipulations. Rats in the phosphate buffered saline (PBS) group were intrathecally injected with 0.01 mmol/L PBS (20 μL). Rats in the fluorocitrate group were subjected to 1 μmol/L fluorocitrate (20 μL). Rats in the minocycline group were intrathecally injected with 5 g/L minocycline (20 μL). Rats in the minocycline and fluorocitrate group received a mixture (20 μL) of 5 g/L minocycline and 1 μmol/L fluorocitrate. Following model establishment, drugs were administered once a day. MAIN OUTCOME MEASURES: At 7 and 14 days following model induction, glial fibrillary acidic protein expression in the spinal dorsal horn was measured by immunofluorescence microscopy. Six sections with significant glial fibrillary acidic protein -positive expression were

  18. Paraplegia of late onset in adolescents with healed childhood caries of dorsal spine: A cause of pressure on the cord and treatment

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    Paravastu Rangachari

    2008-01-01

    Full Text Available Background: Paraplegia of late onset in adolescents with caries of dorsal spine is considered to be due to the reactivation of infection. Internal salient at the level of acute kyphotic deformity of the dorsal spine is formed by posterior cartilaginous remains of grossly destroyed vertebral bodies. The author presents a study of eight adolescent patients with paraplegia of late onset associated with severe kyphotic deformity of dorsal spine with observations on the cause of paraplegia, the final neurological outcome following anterior decompression and its prevention. Materials and Methods: Eight adolescent patients mean age 14.4 yrs 6 males and 2 females with healed childhood caries of dorsal spine, having a mean kyphotic angle of 80° (range 60°-140° presented with paraplegia of late onset. Of these patients, two had medical research council grade 0 muscle power; four had grade 2 muscle power, and two others had grade 3 muscle power in the lower limbs and were unable to walk unaided. One patient with 140° kyphoscoliotic deformity with grade 3 muscle power had post-polio residual paralysis (PPRP in addition. All patients were subjected to thorough anterior spinal decompression through transthoracic, transpleural thoracotomy from the left side. Results: In six of the eight patients, the spine at the site of deformity being very rigid, the deformity could not be corrected and the intervertebral gap was bridged with appropriate autogenous tricortical cortico cancelluous bone graft. In one patient (case 4, the kyphotic deformity could be corrected by 50%. In one patient with 140° kyphosis and PPRP, the gap after the decompression of cord, could not be bridged with bone graft and was given a custom made, well molded plastic black shell to wear while walking and, in particular, while traveling in a vehicle. In all seven patients, bone grafts took six months for bridging the intervertebral gaps. All patients recovered to grade 4 muscle power 6

  19. The role of dorsal root ganglia activation and brain-derived neurotrophic factor in multiple sclerosis.

    Science.gov (United States)

    Zhu, Wenjun; Frost, Emma E; Begum, Farhana; Vora, Parvez; Au, Kelvin; Gong, Yuewen; MacNeil, Brian; Pillai, Prakash; Namaka, Mike

    2012-08-01

    Multiple sclerosis (MS) is characterized by focal destruction of the white matter of the brain and spinal cord. The exact mechanisms underlying the pathophysiology of the disease are unknown. Many studies have shown that MS is predominantly an autoimmune disease with an inflammatory phase followed by a demyelinating phase. Recent studies alongside current treatment strategies, including glatiramer acetate, have revealed a potential role for brain-derived neurotrophic factor (BDNF) in MS. However, the exact role of BDNF is not fully understood. We used the experimental autoimmune encephalomyelitis (EAE) model of MS in adolescent female Lewis rats to identify the role of BDNF in disease progression. Dorsal root ganglia (DRG) and spinal cords were harvested for protein and gene expression analysis every 3 days post-disease induction (pdi) up to 15 days. We show significant increases in BDNF protein and gene expression in the DRG of EAE animals at 12 dpi, which correlates with peak neurological disability. BDNF protein expression in the spinal cord was significantly increased at 12 dpi, and maintained at 15 dpi. However, there was no significant change in mRNA levels. We show evidence for the anterograde transport of BDNF protein from the DRG to the dorsal horn of the spinal cord via the dorsal roots. Increased levels of BDNF within the DRG and spinal cord in EAE may facilitate myelin repair and neuroprotection in the CNS. The anterograde transport of DRG-derived BDNF to the spinal cord may have potential implications in facilitating central myelin repair and neuroprotection.

  20. Origin and central projections of rat dorsal penile nerve: possible direct projection to autonomic and somatic neurons by primary afferents of nonmuscle origin.

    Science.gov (United States)

    Núñez, R; Gross, G H; Sachs, B D

    1986-05-22

    Cell number, size, and somatotopic arrangement within the spinal ganglia of the cells of origin of the rat dorsal penile nerve (DPN), and their spinal cord projections, were studied by loading the proximal stump of the severed DPN with horseradish peroxidase (HRP). The DPN sensory cells were located entirely in the sixth lumbar (L6) dorsal root ganglia (DRG), in which a mean of 468 +/- 78 cells per side were observed, measuring 26.7 +/- 0.8 microns in their longest axis (range 10-65 microns) and distributed apparently randomly within the ganglia. Within the spinal cord, no retrograde label was found, i.e., no motoneurons were labeled, indicating that in the rat the DPN is formed exclusively of sensory nerve fibers. Although labeled fibers entered the cord only through L6, transganglionically transported HRP was evident in all spinal segments examined, i.e., T13-S2. Labeled fibers projected along the inner edge of the dorsal horn (medial pathway) throughout their extensive craniosacral distribution. However, laminar distribution varied with spinal segment. In the dorsal horn, terminals or preterminal axons were found in the dorsal horn marginal zone (lamina I), the substantia gelatinosa (lamina II), the nucleus proprius (laminae III and IV--the most consistent projection), Clarke's column (lamina VI), and the dorsal gray commissure. In the ventral horn, terminals were found in lamina VII and lamina IX. Label apposed to cell somas and dendrites in lamina VII may represent direct primary afferent projections onto sympathetic autonomic neurons. In lamina IX, labeled terminals delineated the somas and dendrites of cells that appeared to be motoneurons. This is the first description of an apparently monosynaptic contact onto motoneurons by a primary afferent of nonmuscle origin.

  1. 姜黄素对2型糖尿病神经痛大鼠脊髓背角和背根神经节RAGE表达的影响%Effects of curcumin on expression of receptor for advanced glycation end-products in spinal dorsal horn and dorsal root ganglion of rats with type 2 diabetic neuropathic pain

    Institute of Scientific and Technical Information of China (English)

    史小婷; 徐霞; 曹红; 李佳佳; 吴绍胜; 李军

    2014-01-01

    Objective To evaluate the effects of curcumin on the expression of receptor for advanced glycation end-products (RAGE) in the spinal dorsal horn and dorsal root ganglion (DRG) of the rats with type 2 diabetic neuropathic pain (DNP).Methods Male Sprague-Dawley rats,weighing 160-180 g,were used in this study.Type 2 diabetes mellitus was induced by high-fat and high-sucrose diet for 8 weeks and intraperitoneal streptozotocin (STZ) 35 mg/kg and confirmed by fasting blood glucose level ≥ 16.7 mmol/L 3 days later.Type 2 DNPwas confirmed by the mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) measured on day 14 after STZ administration less than 80% of the baseline value.Eighty-one rats with type 2 DNP were randomly divided into 3 groups (n =27 each) using a random number table:DNP group,DNP + curcumin group (DCur group),and DNP+ solvent group (group DSC).In DCur and DSC groups,curcumin 100 mg· kg-1 · d-1 and corn oil 4 ml · kg-1 · d-1 were injected intraperitonally,respectively,for 14 consecutive days starting from the day 14 after STZ administration.Another 27 normal male Sprague-Dawley rats served as control group (group C) and were fed with normal forage.MWT and TWL were measured before STZ injection,at day 14 after STZ injection,and on 3,7 and 14 days after curcumin injection.RAGE positive cells were determined by immuno-histochemistry and the expression of RAGE by Western blot in the spinal dorsal horn and DRG after MWT and TWL were measured on 3,7 and 14 days after curcumin injection.Results Compared with group C,MWT was significantly decreased and TWL was shortened at 14 days after STZ injection and each time point after curcumin injection,the rate of RAGE positive cells in the spinal dorsal horn and DRG was increased at each time point after curcumin injection,and the expression of RAGE was up-regulated in the spinal dorsal horn at each time point after curcumin injection and in the DRG at 7 and 14 days after curcumin

  2. Connections between 5-HT-containing terminals and 5-HT2A receptor and γ-aminobutyric acid or glycine co-existed neurons in the rat medullary dorsal horn

    Institute of Scientific and Technical Information of China (English)

    LI Hui; LI Yun-qing

    2001-01-01

    Objective: To investigate the connections between serotonin (5-HT)-containing terminals and 5-HT2A receptor (5-HT2AR)/γ-aminobutyric acid (GABA) or 5-HT2AR/glycine co-existed neurons in the rat medullary dorsal horn (MDH).Methods: Immunofluorescence histochemical triple-staining for 5-HT, 5-HT2AR, GABA or glycine. Results: 5-HT-immunoreaetive fibers and terminals were chiefly located in the superficial laminae (laminae Ⅰ and Ⅱ) of the MDH. Neurons exhibiting 5-HT2AR-, GABA- or glycine-immunoreactivities were mainly observed in the superficial laminae. Some 5-HT2AR-immunopositive neurons also exhibited GABA- or glycine-immunoreaetivities. 5-HT-containing terminals made close contacts with 5-HT2AR/GABA or 5-HT2AR/glycine co-existed neurons. Conclusion: 5-HT2AR/GABA or 5-HT2AR /glycine co-exist in some of the neurons in the superficial laminae of the MDH. 5-HT-immunoreactive terminals form close connections with 5-HT2AR/GABA or 5-HT2AR/glycine co-existed neurons.

  3. Effects of tegaserod on Fos,substance P and calcitonin gene-related peptide expression induced by colon inflammation in lumbarsacral spinal cord

    Institute of Scientific and Technical Information of China (English)

    Yi-Ning Sun; Jin-Yan Luo

    2004-01-01

    AIM: To investigate the mechanisms of tegaserod, a partial 5-HT4 agonist, in reducing visceral sensitivity by observing Fos, substance P (SP) and calcitonin gene-related peptide (CGRP) expression in the lumbarsacral spinal cord inducedby colonic inflammation in rats.METHODS: Twenty-four male rats with colonic inflammation induced by intraluminal instillation of trinitrobenzenesulfonic acid (TNBS) were divided into 3 groups. Treatment group Treatment group 2: intra-gastric administration of tegaserod,saline, 2.0 mL/d. After 7 d of intra-gastric administration,lumbarsacral spinal cord was removed and processed for Fos, SP and CGRP immunohistochemistry.RESULTS: In rats of the control group, the majority of Fos labeled neurons was localized in deeper laminae of the lumbarsacral spinal cord (L5-S1). SP and CGRP were primarily expressed in the superficial laminae of the spinal cord after TNBS injection. Intra-gastric administration of tegaserod neurons (22.0±7.7) and SP density (12.5±1.4) in the dorsal horn in the lumbarsacral spinal cord compared to those of the control group (62.2±18.9, 35.9±8.9, P<0.05). However,CGRP content in dorsal horn did not significantly reduce in rats of treatment group 1 (1.2±1.1) compared to that of the control group (2.8±2.4, P>0.05). Neither Fos expression nor SP or CGRP density in the dorsal horn significantly declined in rats of treatment group 2 compared to those of the control group (P>0.05).CONCLUSION: Tegaserod can significantly reduce Fos labeled neurons in the lumbarsacral spinal cord induced by colonic inflammation. Tegaserod may reduce visceral sensitivity by inhibiting SP expression in the dorsal horn of spinal cord.

  4. Immunohistochemical and hodological characterization of calbindin-D28k-containing neurons in the spinal cord of the turtle, Pseudemys scripta elegans.

    Science.gov (United States)

    Morona, Ruth; López, Jesús M; Domínguez, Laura; González, Agustín

    2007-02-01

    Neurons and fibers containing the calcium-binding protein calbindin-D28k (CB) were studied by immunohistochemical techniques in the spinal cord of adult and juvenile turtles, Pseudemys scripta elegans. Abundant cell bodies and fibers immunoreactive for CB were widely and distinctly distributed throughout the spinal cord. Most neurons and fibers were labeled in the superficial dorsal horn, but numerous cells were also located in the intermediate gray and ventral horn. In the dorsal horn, most CB-containing cells were located in close relation to the synaptic fields formed by primary afferents, which were not labeled for CB. Double immunohistofluorescence demonstrated distinct cell populations in the dorsal horn labeled only for CB or nitric oxide synthase, whereas in the dorsal part of the ventral horn colocalization of nitric oxide synthase was found in about 6% of the CB-immunoreactive cells in this region. Choline acetyltransferase immunohistochemistry revealed that only about 2% of the neurons in the dorsal part of the ventral horn colocalized CB, whereas motoneurons were not CB-immunoreactive. The involvement of CB-containing neurons in ascending spinal projections to the thalamus, tegmentum, and reticular formation was demonstrated combining the retrograde transport of dextran amines and immunohistochemistry. Similar experiments demonstrated supraspinal projections from CB-containing cells mainly located in the reticular formation but also in the thalamus and the vestibular nucleus. The revealed organization of the neurons and fibers containing CB in the spinal cord of the turtle shares distribution and developmental features, colocalization with other neuronal markers, and connectivity with other tetrapods and, in particular with mammals.

  5. Orexin A and Orexin Receptor 1 axonal traffic in dorsal roots at the CNS/PNS interface

    Directory of Open Access Journals (Sweden)

    Damien eColas

    2014-02-01

    Full Text Available Hypothalamic orexin/hypocretin neurons send long axonal projections through the dorsal spinal cord in lamina I-II of the dorsal horn at the interface with the peripheral nervous system (PNS. We show that in the dorsal horn OXA fibers colocalize with substance P (SP positive afferents of dorsal root ganglia (DRG neurons known to mediate sensory processing. Further, OR1 is expressed in p75NTR and SP positive DRG neurons, suggesting a potential signaling pathway between orexin and DRG neurons. Interestingly, DRG sensory neurons have a distinctive bifurcating axon where one branch innervates the periphery and the other one the spinal cord (pseudo-unipolar neurons, allowing for potential functional coupling of distinct targets. We observe that OR1 is transported selectively from DRG toward the spinal cord, while OXA is accumulated retrogradely toward the DRG. We hence report a rare situation of asymmetrical neuropeptide receptor distribution between axons projected by a single neuron. This molecular and cellular data are consistent with the role of OXA/OR1 in sensory processing, including DRG neuronal modulation, and support the potential existence of an OX/HCRT circuit between CNS and PNS.

  6. NMDA受体通道参与大鼠脊髓背角C纤维诱发电位LTP的表达%NMDA Receptor Channels Are Involved in The Expression of Long-term Potentiation of C-fiber Evoked Field Potentials in Rat Spinal Dorsal Horn

    Institute of Scientific and Technical Information of China (English)

    张红梅; 周利君; 胡能伟; 张彤; 刘先国

    2006-01-01

    different from that produced by the dose of 0.5 mg/kg. The similar inhibitory effect on spinal LTP was also observed, when MK 801 was applied locally at the recording segments of spinal cord. To confirm the above results, a competitive NMDA receptor antagonist AP V was tested. Spinal application of AP V at a concentration of 100 μmol/L produced a stronger depression than at 50 μmol/L. When the concentration of AP V increased to 200 μmol/L, no further depression was observed. These results indicate that NMDA receptor channels are involved in the expression of LTP of C-fiber evoked field potentials in the rat spinal dorsal horn.

  7. Identification and quantification of neuropeptides in naïve mouse spinal cord using mass spectrometry reveals [des-Ser1]-cerebellin as a novel modulator of nociception.

    Science.gov (United States)

    Su, Jie; Sandor, Katalin; Sköld, Karl; Hökfelt, Tomas; Svensson, Camilla I; Kultima, Kim

    2014-07-01

    Neuropeptide transmitters involved in nociceptive processes are more likely to be expressed in the dorsal than the ventral horn of the spinal cord. This study was designed to examine the relative distribution of neuropeptides between the dorsal and ventral spinal cord in naïve mice using liquid chromatography, high-resolution mass spectrometry. We identified and relatively quantified 36 well-characterized full-length neuropeptides and an additional 168 not previously characterized peptides. By extraction with organic solvents we identified seven additional full-length neuropeptides. The peptide [des-Ser1]-cerebellin (desCER), originating from cerebellin precursor protein 1 (CBLN1), was predominantly expressed in the dorsal horn. Immunohistochemistry showed the presence of CBLN1 immunoreactivity with a punctate cytoplasmic pattern in neuronal cell bodies throughout the spinal gray matter. The signal was stronger in the dorsal compared to the ventral horn, with most CBLN1 positive cells present in outer laminae II/III, colocalizing with calbindin, a marker for excitatory interneurons. Intrathecal injection of desCER induced a dose-dependent mechanical hypersensitivity but not heat or cold hypersensitivity. This study provides evidence for involvement of desCER in nociception and provides a platform for continued exploration of involvement of novel neuropeptides in the regulation of nociceptive transmission. Neuropeptides involved in nociceptive processes are more likely to be expressed in the dorsal than the ventral horn of spinal cord. Well-characterized full-length neuropeptides as well as uncharacterized neuropeptides were quantified by mass spectrometry. The CBLN1-derived peptide [des-Ser1]-cerebellin (desCER) is predominantly expressed in the dorsal horn, and intrathecal injection of desCER induced a dose-dependent mechanical hypersensitivity.

  8. Tumor necrosis factor α sensitizes spinal cord TRPV1 receptors to the endogenous agonist N-oleoyldopamine

    Directory of Open Access Journals (Sweden)

    Spicarova Diana

    2010-08-01

    Full Text Available Abstract Modulation of synaptic transmission in the spinal cord dorsal horn is thought to be involved in the development and maintenance of different pathological pain states. The proinflamatory cytokine, tumor necrosis factor α (TNFα, is an established pain modulator in both the peripheral and the central nervous system. Up-regulation of TNFα and its receptors (TNFR in dorsal root ganglion (DRG cells and in the spinal cord has been shown to play an important role in neuropathic and inflammatory pain conditions. Transient receptor potential vanilloid 1 (TRPV1 receptors are known as molecular integrators of nociceptive stimuli in the periphery, but their role on the spinal endings of nociceptive DRG neurons is unclear. The endogenous TRPV1 receptor agonist N-oleoyldopamine (OLDA was shown previously to activate spinal TRPV1 receptors. In our experiments the possible influence of TNFα on presynaptic spinal cord TRPV1 receptor function was investigated. Using the patch-clamp technique, miniature excitatory postsynaptic currents (mEPSCs were recorded in superficial dorsal horn neurons in acute slices after incubation with 60 nM TNFα. A population of dorsal horn neurons with capsaicin sensitive primary afferent input recorded after the TNFα pretreatment had a basal mEPSC frequency of 1.35 ± 0.20 Hz (n = 13, which was significantly higher when compared to a similar population of neurons in control slices (0.76 ± 0.08 Hz; n = 53; P

  9. The distribution of primary nitric oxide synthase- and parvalbumin- immunoreactive afferents in the dorsal funiculus of the lumbosacral spinal cord in a dog.

    Science.gov (United States)

    Marsala, Jozef; Lukácová, Nadezda; Kolesár, Dalibor; Sulla, Igor; Gálik, Ján; Marsala, Martin

    2007-06-01

    1. The aim of the present study was to examine the distribution of unmyelinated, small-diameter myelinated neuronal nitric oxide synthase immunoreactive (nNOS-IR) axons and large-diameter myelinated neuronal nitric oxide synthase and parvalbumin-immunoreactive (PV-IR) axons in the dorsal funiculus (DF) of sacral (S1-S3) and lumbar (L1-L7) segments of the dog.2. nNOS and PV immunohistochemical methods were used to demonstrate the presence of nNOS-IR and PV-IR in the large-diameter myelinated, presumed to be proprioceptive, axons in the DF along the lumbosacral segments.3. Fiber size and density of nNOS-IR and PV-IR axons were used to compartmentalize the DF into five compartments (CI-CV). The first compartment (CI) localized in the lateralmost part of the DF, containing both unmyelinated and small-diameter myelinated nNOS-IR axons, is homologous with the dorsolateral fasciculus, or Lissauer tract. The second compartment (CII) having similar fiber organization as CI is situated more medially in sacral segments. Rostrally, in lower lumbar segments, CII moves more medially, and at upper lumbar level, CII reaches the dorsomedial angle of the DF and fuses with axons of CIV. CIII is the largest in the DF and the only one containing large-diameter myelinated nNOS-IR and PV-IR axons. The largest nNOS-IR and PV-IR axons of CIII (8.0-9.2 mum in diameter), presumed to be stem Ia proprioceptive afferents, are located in the deep portion of the DF close to the dorsal and dorsomedial border of the dorsal horn. The CIV compartment varies in shape, appearing first as a small triangular area in S3 and S2 segments, homologous with the Philippe-Gombault triangle. Beginning at S1 level, CIV acquires a more elongated shape and is seen throughout the lumbar segments as a narrow band of fibers extending just below the dorsal median septum in approximately upper two-thirds of the DF. The CV is located in the basal part of the DF. In general, CV is poor in nNOS-IR fibers; among them

  10. Spinal cord projections to the cerebellum in the mouse.

    Science.gov (United States)

    Sengul, Gulgun; Fu, YuHong; Yu, You; Paxinos, George

    2015-09-01

    The projections from the spinal cord to the cerebellar cortex were studied using retrograde neuronal tracers. Thus far, no study has shown the detailed topographic mapping of the projections from the spinal neuron clusters to the cerebellar cortex regions for experimental animals, and there are no studies for the mouse. Tracers Fluoro-Gold and cholera toxin B were injected into circumscribed regions of the cerebellar cortex, and retrogradely labeled spinal cord neurons were mapped throughout the spinal cord. Spinal projections to the cerebellar cortex were mainly from five neuronal columns--central cervical nucleus, dorsal nucleus, lumbar and sacral precerebellar nuclei, and lumbar border precerebellar cells--and from scattered neurons located in the deep dorsal horn and laminae 6-8. The spinocerebellar projections to the cortex were mainly to the vermis. All five precerebellar cell columns projected to both anterior and posterior parts of the cerebellar cortex. Results of this study provide an amendment to the known rostral and caudal boundaries of the precerebellar cell columns in the mouse. Scattered precerebellar neurons in the most caudal deep dorsal horn and laminae 6-8 projected exclusively to the anterior part of the cerebellar cortex. In this study, no labeled spinal neurons were found to project to the lobules 6 and 7 of the cerebellar vermis, the flocculus, and the paraflocculus. Spinocerebellar neurons were located bilaterally, but the majority of the projections were contralateral for the central cervical nucleus, and ipsilateral for the remaining spinal precerebellar neuronal clusters.

  11. Expression of NMDAR, CGRP and the changes of microglia in sacral dorsal horn of irritable bowel syndrome rats%肠易激综合征大鼠骶髓后角中NMDAR、CGRP表达以及小胶质细胞的变化

    Institute of Scientific and Technical Information of China (English)

    崔曼莉; 王景杰; 秦明; 王旭霞; 杨琦; 黄裕新

    2011-01-01

    目的 观察肠易激综合征(irritable bowel syndrome,IBS)大鼠腹直肌肌电变化以及脊髓背角中NMDAR(N-methyldaspartate receportes,NMDAR)、CGRP(calcitonin gene-related peptide),以及骶髓后联合核(dorsal commissural nucleus,DCN)中小胶质细胞的变化,为研究IBS内脏敏化提供理论依据.方法 以旋毛虫感染大鼠致肠易激综合征大鼠模型,然后随机分为2组:IBS无刺激组和IBS结肠刺激组.另外选择5只正常大鼠作为对照.分别测定各组腹直肌肌电以及NMDAR、CGRP表达以及小胶质细胞的变化.结果 IBS结肠刺激组大鼠腹直肌肌电、大鼠骶髓后角中NMDAR和CGRP的表达以及骶髓后联合核中的小胶质细胞活化较正常对照组及IBS未刺激组均显著增强.结论 IBS大鼠内脏敏化可能与骶髓后角神经活性物质活化以及DCN中小胶质细胞的活化相关,这些物质以及细胞的活化进而导致神经元敏化的发生.%Objective To investigate the myoelectric changes of the rectus ahdominis in irritable bowel syndrome( IBS ) rats, the expression of NMDAR and CGRP in the dorsal horn of spinal cord of rats with IBS, and the activation of mic:roglial cells in dorsal commissural nucleus ( DCN ) , and to provide a theoretical basis for visceral hyperalgesia of the rats with IBS. Methods The rats were gavaged with the Trichinella spiralis to establish the irritable bowel syndrome model. The model rats were randomly divided into IBS group and IBS + colon distension group. Five normal rats were chosen as controls. The myoelectric changes of the rec:tus abdominis were observed. and the expression of NMDAR, CGRP and changes of microglia were determined using immunofluorescence method. Results The electro-activity of the rectus abdominis , the expression of NMDAR. CCRP and activation of microglia of the sacral joint nuclear were significantly enhanced in IBS rats with colon distension than that in the normal rats and non-stimulation IBS rats. Conclusion

  12. 姜黄素对糖尿病神经病理性痛大鼠脊髓背角NR2B与NR1活性的影响%Effects of curcumin on activity of NR2B and NR1 in spinal dorsal horn in a rat model of diabetic neuropathic pain

    Institute of Scientific and Technical Information of China (English)

    李佳佳; 马益梅; 连庆泉; 李军; 曹红

    2014-01-01

    Objective To evaluate the effects of curcumin on the activity of NR2B and NR1 in the spinal dorsal horn in a rat model of diabetic neuropathic pain (DNP).Methods Diabetes mellitus was induced by high-sucrose and high-fat diet and intraperitoneal streptozotocin 35 mg/kg,then confirmed by fasting blood glucose level ≥ 16.7 mmol/L 3 days later in male Sprague-Dawley rats.DNP was confirmed by the mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) measured on day 14 after streptozotocin administration < 80% of the baseline value.The rats were then randomly divided into 3 groups (n =27 each) using a random number table:DNP,DNP+ curcumin group (group DCur)and DNP + solvent control group (group DSC).Curcumin 100 mg· kg-1 · d-1 and corn oil 4 ml· kg-1 · d-1 were injected intraperitoneally for 14 consecutive days starting from 14 days after administration of streptozotocin in DCur and DSC groups,respectively.Another 27 normal male Sprague-Dawley rats served as control group (group C) and were fed with normal forage.At 3,7 and 14 days after curcumin injection,MWT and TWL were measured and the lumbar segments (L4-6) of the spinal cord were removed.The expression of pTyr1472-NR2B and pSer896-NR1 in the spinal dorsal horn was determined by immunohistochemistry and Western blot.Results Compared with group C,MWT was significantly decreased,TWL was shortened,and the expression of pTyr1472-NR2B was up-regulated at each time point in group DNP.Compared with group DNP,MWT was significantly increased,and TWL was prolonged at 7 days after curcumin injection,and the expression of pTyr1472-NR2B was down-regulated at 3 days after curcumin injection in group DCur.There was no significant difference in each parameter between DNP and DSC groups,and in the expression of pSer896-NR1 between the four groups.Conclusion The mechanism by which curcumin mitigates neuropathic pain in type 2 diabetic rats may be related to inhibition of up-regulation of p

  13. 青藤碱对神经病理性痛大鼠脊髓背角神经元凋亡的影响%Effects of sinomenine on neuronal apoptosis in spinal dorsal horns in a rat model of neuropathic pain

    Institute of Scientific and Technical Information of China (English)

    郝珍; 冷玉芳; 金建萍; 胡晓慧; 赵文宇; 周菲; 于洁; 吴小精

    2014-01-01

    Objective To evaluate the effects of sinomenine on neuronal apoptosis in the spinal dorsal horns in a rat model of neuropathic pain (NP).Methods One hundred and eight male Wistar rats,weighing 180-220 g,were randomly divided into 3 groups with 36 animals in each group:sham operation group (group S),NP group and sinomenine group (group SIN).The animals were anesthetized with intraperitoneal chloral hydrate.In groups NP and SIN,NP was induced by chronic constrictive injury.The sciatic nerve was exposed and four ligatures were placed on the right sciatic nerve at 1 mm intervals with 4-0 chromic catgut.In group S,the right sciatic nerves were exposed,but not ligated.In group SIN,sinomenine 40 mg/kg was injected intraperitoneally once a day starting from the end of operation until one day before the rats were sacrificed.In groups NP and S,the rats received the equal volume of normal saline instead of sinomenine.Twelve animals in each group were randomly chosen at 1 day before operation (T0) and 3,7 and 14 days after operation (T1-33) to measure mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL).The rats in each group were sacrificed at T1-3 after measurement of pain threshold and the lumbar segments (L4-6) of the spinal cord were removed for determination of caspase-3 mRNA and p38MAPK mRNA expression (by real-time fluorescent quantitative PCR) and cell apoptosis (by TUNEL) in the spinal dorsal horn.Apoptosis rate (AR =the number of apoptotic cells/the total number of cells examined) was calculated.Results Compared with group S,MWT and TWL were significantly decreased,the expression of caspase-3 mRNA and p38MAPK mRNA was up-regulated,and AR was increased at T1-3 in NP and SIN groups (P < 0.05).Compared with group NP,MWT and TWL were significantly increased,the expression of caspase-3 mRNA and p38MAPK mRNA was down-regulated,and AR was decreased at T1-3 in group SIN (P < 0.05).MWT and TWL were significantly lower,and the expression of

  14. 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.

  15. The role of α1-adrenoceptors on glutamatergic synapse via GABAB receptors in spinal dorsal horn%α1-肾上腺素受体通过GABAB受体调控脊髓背角神经元谷氨酸能突触传递

    Institute of Scientific and Technical Information of China (English)

    袁维秀; 郭英; 徐娟; 张宏

    2013-01-01

    目的 研究下行去甲肾上腺素系统α1-肾上腺素受体通过GABAB受体调控脊髓背角感觉神经元谷氨酸能突触传递的机制.方法 在急性切取的腰段脊髓切片上,利用全细胞膜片钳法记录α1-肾上腺素受体激动剂苯肾上腺素刺激诱发的脊髓背角浅层神经元谷氨酸能兴奋性突触后电流(eEPSCs),给予GABAB受体特异性拮抗剂CGP55845,进一步观察GABAB受体在苯肾上腺素对突触终末eEPSCs调节过程中的作用.结果 苯肾上腺素显著降低初级传入末梢单突触和多突触eEPSCs幅度,在突触后GABAB受体被从胞内阻断的条件下,再灌流CGP55845,阻断谷氨酸能突触前GABAB受体,可部分拮抗苯肾上腺素对刺激引发的EPSCs (eEPSCs)幅度的抑制作用.结论 位于脊髓背角神经元α1-肾上腺素受体,通过GABAB受体抑制初级传入纤维兴奋性谷氨酸能神经冲动的传入,这种突触前对谷氨酸释放的调节可能是下行肾上腺素能系统对伤害性刺激调控的作用机制.%Objective To investigate the role of α 1-adrenoceptors on glutamatergic synapse via GABAB receptors in spinal dorsal horn. Methods Using whole-cell voltage-clamp recordings on acute spinal cord slice,effect of blockade of α1 -adrenoceptors on glutamatergic synaptic transmission was studied. Results Selective α1 -adrenoceptors agonist phenylephrine significantly reduced the amplitude of monosynaptic and polysynaptic EPSCs evoked from primary afferents. The inhibitory effect of phenylephrine on evoked monosynaptic and polysynaptic glutamatergic EPSCs was largely blocked by the GABAB receptor antagonist CGP55845. Conclusion Activation of α1- adrenoceptors in the spinal cord attenuates glutamatergic input from primary afferents mainly through GABAB receptors, indicating a presynaptic inhibition in the spinal cord may be involved in the regulation of nociception by the descending noradrenergic system.

  16. FUNCTIONAL MAGNETIC RESONANCE IMAGING OF THE SPINAL CORD DURING SENSORY STIMULATION IN DIABETIC RATS

    Science.gov (United States)

    Malisza, Krisztina L.; Jones, Cheryl; Gruwel, Marco L.H.; Foreman, Derek; Fernyhough, Paul; Calcutt, Nigel A.

    2009-01-01

    Purpose To determine if differences exist between control and diabetic rats in functional MRI activity of the spinal cord and if fMRI can provide a means of early detection of diabetic neuropathy. Materials and Methods fMRI of the spinal cord, using noxious electrical stimulation (15 V (~8 mA), 0.3 ms, 3 Hz) of the hind paw, was performed in groups of control and streptozotocin (STZ)-induced type 1 diabetic rats. Results Diabetic rats were lighter, hyperglycemic and had lower blood pH than controls. FMRI activity at the lumbar enlargement of the spinal cord was identified in the dorsal horn ipsilateral to stimulus of all animals. Signal intensity changes across the lumbar spinal cord during periods of activity were not significantly different between control and diabetic rats, with a trend towards greater signal changes in controls. When specific regions of the spinal cord were analyzed, control rats exhibited significantly increased BOLD fMRI activity in both ipsilateral and contralateral dorsal horn compared to diabetic rats. Conclusion The results of this study are consistent with reports that primary afferent input to the spinal cord is diminished by diabetes, and suggest that BOLD fMRI may be useful in early detection of diabetic neuropathy. PMID:19629995

  17. 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.

  18. Effects of sciatic nerve transection on glucose uptake in the presence and absence of lactate in the frog dorsal root ganglia and spinal cord

    Directory of Open Access Journals (Sweden)

    F Rigon

    Full Text Available Frogs have been used as an alternative model to study pain mechanisms because the simplicity of their nervous tissue and the phylogenetic aspect of this question. One of these models is the sciatic nerve transection (SNT, which mimics the clinical symptoms of “phantom limb”, a condition that arises in humans after amputation or transverse spinal lesions. In mammals, the SNT increases glucose metabolism in the central nervous system, and the lactate generated appears to serve as an energy source for nerve cells. An answerable question is whether there is elevated glucose uptake in the dorsal root ganglia (DRG after peripheral axotomy. As glucose is the major energy substrate for frog nervous tissue, and these animals accumulate lactic acid under some conditions, bullfrogs Lithobates catesbeianus were used to demonstrate the effect of SNT on DRG and spinal cord 1-[14C] 2-deoxy-D-glucose (14C-2-DG uptake in the presence and absence of lactate. We also investigated the effect of this condition on the formation of 14CO2 from 14C-glucose and 14C-L-lactate, and plasmatic glucose and lactate levels. The 3-O-[14C] methyl-D-glucose (14C-3-OMG uptake was used to demonstrate the steady-state tissue/medium glucose distribution ratio under these conditions. Three days after SNT, 14C-2-DG uptake increased, but 14C-3-OMG uptake remained steady. The increase in 14C-2-DG uptake was lower when lactate was added to the incubation medium. No change was found in glucose and lactate oxidation after SNT, but lactate and glucose levels in the blood were reduced. Thus, our results showed that SNT increased the glucose metabolism in the frog DRG and spinal cord. The effect of lactate on this uptake suggests that glucose is used in glycolytic pathways after SNT.

  19. 大鼠脊髓背角神经元痛放电确定性行为的年龄相关变化%Age-related changes in deterministic behaviors of nociceptive firing of rat dorsal horn neurons

    Institute of Scientific and Technical Information of China (English)

    郑继宏; 冯威; 菅忠; 陈军

    2004-01-01

    为阐明脊髓背角神经元痛放电的年龄相关的动力学变化,本研究采用非线性预报方法,对两组不同年龄大鼠(成年青龄鼠3~4月龄,老年鼠>22月龄)组织损伤诱发的脊髓背角神经元痛放电峰峰间期序列进行了确定性行为的定量分析.结果显示,皮下注入蜜蜂毒,在两组大鼠均诱发脊髓背角广动力域神经元长时程放电,而老龄大鼠的痛放电峰峰间期序列表现出更高的可确定性.本研究表明,单个神经元的痛放电动力学在整个生命过程中并不是恒定不变的,伤害性神经元活动的年龄相关动力学变化可能是老年人群中多样化痛反应的内在机制之一.%To demonstrate the age-related changes in the dynamics of the nociceptive discharge of dorsal horn nociceptive neurons, the nonlinear prediction method was used to quantify the degree of deterministic behavior within the interspike interval series of tissue injuryinduced firing of spinal nociceptive neurons in anesthetized adult young (3~4 months) and aged (>22 months) rats. Subcutaneous bee venom injection induced long-term discharge of spinal wide dynamic range (WDR) neurons in both groups. However, the nociceptive discharge of single WDR neurons in the aged group showed higher determinism when compared with the adult young rats. This result suggests that the dynamics of single nocicepfive neurons may not remain constant throughout the life span, and this age-associated change may be an underlying mechanism for various pain manifestations in the elderly population.

  20. The search for novel analgesics: re-examining spinal cord circuits with new tools

    Science.gov (United States)

    Smith, Kelly M.; Madden, Jessica F.; Callister, Robert J.; Hughes, David I.; Graham, Brett A.

    2014-01-01

    In this perspective, we propose the absence of detailed information regarding spinal cord circuits that process sensory information remains a major barrier to advancing analgesia. We highlight recent advances showing that functionally discrete populations of neurons in the spinal cord dorsal horn (DH) play distinct roles in processing sensory information. We then discuss new molecular, electrophysiological, and optogenetic techniques that can be employed to understand how DH circuits process tactile and nociceptive information. We believe this information can drive the development of entirely new classes of pharmacotherapies that target key elements in spinal circuits to selectively modify sensory function and blunt pain. PMID:24616699

  1. 脊髓背角神经元上调Nav1.8通道参与缺血再灌注损伤后痛觉过敏的机制%Mechanisms of ischemia-reperfusion induced hyperalgesia via up-regulation of neu-ronal Nav1. 8 channel in spinal dorsal horn

    Institute of Scientific and Technical Information of China (English)

    李晓倩; 张再莉; 马虹

    2016-01-01

    Objective To observe the effects of intrathecal injection (IT) of Nav1. 8 channel inhibitor 619C89 on hyperalgesia and spinal cord levels of neuronal Nav1. 8 expressions in rat model of spinal cord ischemia-reperfusion injury ( SCIRI) . Methods Male Sprague-Dawley rats were randomly divided into three groups:group S, group H (SCIRI+IT NS) and Nav1. 8 channel inhibitor group (group I,SCIRI+IT 5 μg/30 μL 619C89). The lumbar intrath-ecal catheters were implanted in L5-6 of rats and SCIRI models were established by aortic arch occlusion for 14 min. The thermal and mechanical nociceptive thresholds were assessed by paw withdrawal latency ( PWL ) to radiant heat and von Frey filaments. The 619C89 was administered intrathecally for 3 days before surgery. The spinal mRNA expression of Nav1. 8 was assessed by Real time-PCR and double immunofluorescence staining was performed for examination of the distribution of neurons and Nav1. 8 and also quantification of NeuN/Nav1. 8 positive cells of dorsal horn at 1,3,5, 7 and 14 days after surgery. Results Compared with group S,animals in group H had significantly lower mechanical and thermal pain thresholds,but higher spinal mRNA expression of Nav1. 8 ( P<0. 05 ) . Rats in group I had signifi-cantly higher mechanical and thermal pain thresholds and significantly lower mRNA expression of Nav1. 8 compared with those in group H (at any observed time points after IR,but most significantly at 7 days,P<0. 05). Double fluo-rescent staining showed the distribution of increased fluorescence intensity of Nav1. 8 was similar to that of fluorescent staining of NeuN ( neuronal marker) . The number of NeuN/Nav1. 8 positive cells was greatly increased in group H, whereas the number was obviously decreased in group I ( P<0. 05 ) . Conclusion Up-regulation of neuronal Nav1. 8 channel in spinal dorsal horn plays a role in IR-induced hyperalgesia.%目的:观察鞘内注射钠通道抑制剂619C89对脊髓缺血再灌注损伤引起的痛觉过

  2. The effect of semiconditional dorsal penile nerve electrical stimulation on capacity and compliance of the bladder with deformity in spinal cord injury patients: a pilot study.

    Science.gov (United States)

    Lee, Y-H; Kim, S-H; Kim, J M; Im, H T; Choi, I S; Lee, K W

    2012-04-01

    Bladder capacity, bladder compliance, the volume of the first overactive contraction, maximal volume during cystometry (CMG) and the vesicoureteral reflux, bladder wall deformity before and after semiconditional stimulation on DPN. To evaluate the effect of the semiconditional electrical stimulation on dorsal penile nerve (DPN) to improve the complicated bladder function in male with spinal cord injury (SCI). Semiconditional stimulation system and urodynamic laboratory in a university hospital. Six men (age, 33-59 years) with SCI incurred from 38 to 156 months before this study. semiconditional stimulation parameters were set during CMG and semiconditional stimulation on DPN by surface electrodes via Empi Focus stimulator was applied from 14 to 28 days, at home. Parameters about bladder function were measured before and after stimulation applied. All parameters for bladder after semiconditional stimulation were increased. Also, the vesicoureteral reflux and bladder wall deformity was improved in five of six patients. Semiconditional electrical stimulation on DPN effectively suppresses neurogenic detrusor overactivity and distend the bladder physiologically in the SCI patient with a complicated bladder. The bladder capacity and compliance as well as the bladder wall deformity were improved as a result of this treatment.

  3. Photochemically induced spinal ischaemia: a model of spinal cord trauma in the rat

    Science.gov (United States)

    Olby, Natasha J.; Blakemore, W. F.

    1995-05-01

    Focal thrombosis was induced in the dorsal funiculus of the rat spinal cord by exposing the cord to light following intravenous injection of the photoactive dye, rose bengal. The light source was a 599 standing wave dye laser, pumped by an Innova 70 - 4 argon ion laser (Coherent Ltd, Cambridge, UK) and the light was delivered to the operative site via an optical fiber. The histological characteristics of the development and resolution of the lesion have been studied. Forty rats were examined with light and electron microscopy at various time points between 30 minutes and one month after irradiation and the lesion length was measured. Platelet aggregation, increased extracellular space in the white matter and vacuolation of the neurones and glia of the grey matter were present 30 minutes after injury. Progressive necrosis of the white and grey matter developed over the subsequent 24 hours to produce a fusiform lesion that occupied the dorsal funiculus and dorsal horns of the spinal cord at its center and tapered cranially and caudally along the dorsal columns for a total distance of seven millimeters. By one month after injury the area of necrosis had become a cyst lined by astrocytes ventrolaterally and meningeal cells dorsally. Measurements of lesion length showed a variability of 26%. This model of spinal cord trauma produces a lesion that is sufficiently reproducible to be suitable for performing studies aimed at tissue preservation and repair.

  4. Focusing horn

    CERN Multimedia

    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 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.

  5. [Protein concentration in the neuron--neuroglia system of the anterior horns of the spinal cord in rats following exposure to the tranquilizer diazepam against a background of anticipation stress].

    Science.gov (United States)

    Pevzner, L Z; Iakoubek, B

    1978-02-01

    Anticipation stress was induced in 16 day-old male rats by placing the animals daily for 7 days into individual cells for 45 min. In the end of each 45 min session, an electric stimulation of paws of the animals was done for 2 min. It was shown by visible cytospectrophotometry of amido black-stained spinal cord sections that the anticipation stress for 7 days resulted in an accumulation of the nuclear and cytoplasmic total proteins in the motoneurons of spinal cord anterior horns, with no changes in the body (in fact, in the nuclei) of the glial cells adjacent to the neurons. Intraperitoneal injection of the tranquilizer diazepam (10 mg per kg) 40 min. before the beginning of the last anticipation stress session gave rise to the return to the normal of the protein content per cell in the motoneuron nucleus and cytoplasm while inducing an increase in the quantity of neuroglia cell protein. Differences in the protein metabolism between the neurons and the neuroglia are discussed.

  6. Role of phosphatidylinositol 3-kinase p110β in spinal dorsal horn neurons in the development of arthritic pain in rats: relationship with TRPV1 and ASIC1a%脊髓背角神经元磷脂酰肌醇-3激酶p110β在大鼠关节炎性痛形成中的作用:与辣椒素受体及酸敏感离子通道1a的关系

    Institute of Scientific and Technical Information of China (English)

    张亚军; 杨承祥; 王汉兵; 张斌; 项红兵; 田玉科

    2013-01-01

    -deoxynucleotide group (group AS).AP was induced by injecting complete Freund's adjuvant into the ankle joint cavity of right hindpaw.Normal saline 20 μl,missense oligo-deoxynucleotide 15 μg (20μl) and antisense oligo-deoxynucleotide 15 μg (20 μl) were administered intrathecally once a day for 6 consecutive days starting from the time immediately after arthritis was induced in groups AP,MS and AS,respectively.Mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured 1 day before operation (T0) and on days 4,7,10 after operation (T1-3).The rats were then sacrificed after the last measurement of pain threshold at T3.L4-6 segment of the spinal cord was removed for detection of expression of PI3K p110β (by Western blot),and TRPV1 and ASICla (by immunohistochemistry)in spinal dorsal horn neurons.Results Compared with group C,MWT and TWL were significantly decreased atT1-3,and the expression of PI3K p110β,TRPV1 and ASIC1a was up-regulated in the other 3 groups(P< 0.01).MWT and TWL were significantly higher at T1-3,and the expression of PI3K p110β,TRPV1 and ASIC1a was lower in group AS than in groups AP and MS (P < 0.01).Conclusion PI3K p110β in spinal dorsal horn neurons is involved in the development of AP in rats,and the mechanism is related to up-regulation of TRPV1 and ASIC1a expression in spinal dorsal horn neurons.

  7. Microglia and Spinal Cord Synaptic Plasticity in Persistent Pain

    Directory of Open Access Journals (Sweden)

    Sarah Taves

    2013-01-01

    Full Text Available Microglia are regarded as macrophages in the central nervous system (CNS and play an important role in neuroinflammation in the CNS. Microglial activation has been strongly implicated in neurodegeneration in the brain. Increasing evidence also suggests an important role of spinal cord microglia in the genesis of persistent pain, by releasing the proinflammatory cytokines tumor necrosis factor-alpha (TNFα, Interleukine-1beta (IL-1β, and brain derived neurotrophic factor (BDNF. In this review, we discuss the recent findings illustrating the importance of microglial mediators in regulating synaptic plasticity of the excitatory and inhibitory pain circuits in the spinal cord, leading to enhanced pain states. Insights into microglial-neuronal interactions in the spinal cord dorsal horn will not only further our understanding of neural plasticity but may also lead to novel therapeutics for chronic pain management.

  8. Expressing Constitutively Active Rheb in Adult Dorsal Root Ganglion Neurons Enhances the Integration of Sensory Axons that Regenerate Across a Chondroitinase-Treated Dorsal Root Entry Zone Following Dorsal Root Crush.

    Science.gov (United States)

    Wu, Di; Klaw, Michelle C; Kholodilov, Nikolai; Burke, Robert E; Detloff, Megan R; Côté, Marie-Pascale; Tom, Veronica J

    2016-01-01

    While the peripheral branch of dorsal root ganglion neurons (DRG) can successfully regenerate after injury, lesioned central branch axons fail to regrow across the dorsal root entry zone (DREZ), the interface between the dorsal root and the spinal cord. This lack of regeneration is due to the limited regenerative capacity of adult sensory axons and the growth-inhibitory environment at the DREZ, which is similar to that found in the glial scar after a central nervous system (CNS) injury. We hypothesized that transduction of adult DRG neurons using adeno-associated virus (AAV) to express a constitutively-active form of the GTPase Rheb (caRheb) will increase their intrinsic growth potential after a dorsal root crush. Additionally, we posited that if we combined that approach with digestion of upregulated chondroitin sulfate proteoglycans (CSPG) at the DREZ with chondroitinase ABC (ChABC), we would promote regeneration of sensory axons across the DREZ into the spinal cord. We first assessed if this strategy promotes neuritic growth in an in vitro model of the glial scar containing CSPG. ChABC allowed for some regeneration across the once potently inhibitory substrate. Combining ChABC treatment with expression of caRheb in DRG significantly improved this growth. We then determined if this combination strategy also enhanced regeneration through the DREZ after dorsal root crush in adult rats in vivo. After unilaterally crushing C4-T1 dorsal roots, we injected AAV5-caRheb or AAV5-GFP into the ipsilateral C5-C8 DRGs. ChABC or PBS was injected into the ipsilateral dorsal horn at C5-C8 to digest CSPG, for a total of four animal groups (caRheb + ChABC, caRheb + PBS, GFP + ChABC, GFP + PBS). Regeneration was rarely observed in PBS-treated animals, whereas short-distance regrowth across the DREZ was observed in ChABC-treated animals. No difference in axon number or length between the ChABC groups was observed, which may be related to intraganglionic inflammation induced by the

  9. Local peripheral opioid effects and expression of opioid genes in the spinal cord and dorsal root ganglia in neuropathic and inflammatory pain.

    Science.gov (United States)

    Obara, Ilona; Parkitna, Jan Rodriguez; Korostynski, Michal; Makuch, Wioletta; Kaminska, Dorota; Przewlocka, Barbara; Przewlocki, Ryszard

    2009-02-01

    We investigated the efficacy of local intraplantar (i.pl.) injection of peptide and non-peptide mu-, delta- and kappa-opioid receptor agonists in rat models of inflammatory and neuropathic pain. Locally applied agonists dose-dependently reduced formalin-induced flinching of the inflamed paw and induced antiallodynic and antihyperalgesic effects in sciatic nerve ligation-induced neuropathic pain. These effects were mediated by peripheral opioid receptors localized at the side of tissue/nerve injury, as was demonstrated by selective and non-selective opioid receptors antagonists. The ED(50) dose range of mu- and kappa-agonists required to induce analgesia in neuropathy was much higher than the ED(50) for inflammation; moreover, only delta-agonists were effective in the same dose range in both pain models. Additionally, effective antinociception was achieved at a lower dose of peptide, compared to non-peptide, opioids. Such findings support the use of the peripheral administration of opioid peptides, especially delta-agonists, in treating chronic pain. Furthermore, in order to assess whether adaptations in the expression of opioid genes could underlie the clinical observation of reduced opioid effectiveness in neuropathic pain, we analyzed the abundance of opioid transcripts in the spinal cord and dorsal root ganglia (DRG) during the neuropathy and inflammation. Nerve injury down-regulated mRNA for all types of opioid receptors in the DRG, which is predicted to decrease in the synthesis of opioid receptors to possibly account for the reduced effectiveness of locally administered opioids in neuropathy. The obtained results differentiate inflammatory and neuropathic pain and provide a novel insight into the peripheral effectiveness of opioids in both types of pain.

  10. Reproducibility of resting state spinal cord networks in healthy volunteers at 7 Tesla.

    Science.gov (United States)

    Barry, Robert L; Rogers, Baxter P; Conrad, Benjamin N; Smith, Seth A; Gore, John C

    2016-06-01

    We recently reported our findings of resting state functional connectivity in the human spinal cord: in a cohort of healthy volunteers we observed robust functional connectivity between left and right ventral (motor) horns and between left and right dorsal (sensory) horns (Barry et al., 2014). Building upon these results, we now quantify the within-subject reproducibility of bilateral motor and sensory networks (intraclass correlation coefficient=0.54-0.56) and explore the impact of including frequencies up to 0.13Hz. Our results suggest that frequencies above 0.08Hz may enhance the detectability of these resting state networks, which would be beneficial for practical studies of spinal cord functional connectivity. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Effect of duloxetine on expression of Toll-like receptor 4 in spinal dorsal horn in a rat model of dia-betic neuropathic pain%度洛西汀对糖尿病神经病理性痛大鼠脊髓背角Toll样受体4表达的影响

    Institute of Scientific and Technical Information of China (English)

    陈文君; 周冬梅; 苗蓓; 李伟

    2015-01-01

    =15 each ) using a random number table: group DNP, DNP + normal saline group (group DNP+NS), and DNP + duloxetine 5, 10 and 20 mg∕kg groups (DNP+D5, DNP+D10, DNP+D20 groups). Another normal 15 rats were selected and served as control group ( group C) . Duloxetine 5, 10 and 20 mg∕kg were injected intraperitoneally once a day for 14 consecu⁃tive days starting from 15 days after administration of STZ in DNP+D5 , DNP+D10 and DNP+D20 groups, respectively. The equal volume of normal saline was given instead in group DNP+NS. The mechanical paw withdrawal threshold ( MWT) and thermal paw withdrawal latency ( TWL) were measured on the day before STZ administration and 14, 17, 21 and 28 days after STZ administration. After the last measurement of pain threshold, the L4⁃6 segments of the spinal cord were removed for determination of the expression of TLR4 by immuno⁃histochemistry and Western blot. Results Compared with group C, the MWT was signif⁃icantly decreased, TWL was shortened, and the expression of TLR4 was up⁃regulated in DNP, DNP+D5, DNP+D10 and DNP+D20 groups (P0�05) . Conclusion The mechanism by which duloxetine attenuates DNP is related to down⁃regulated expression of TLR4 in the spinal dorsal horn of rats.

  12. Effect of intrathecal injection of dexmedetomidine on protein kinase C expression of spinal dorsal horn neurons in a rat model of chronic neuralgia%鞘内注射右美托咪定干预慢性神经痛模型大鼠脊髓背角蛋白激酶C的表达

    Institute of Scientific and Technical Information of China (English)

    邓海洪; 马松梅; 肖晓山

    2014-01-01

    BACKGROUND:Dexmedetomidine is an efficient, highly selective alpha-2 adrenergic receptor agonist, with sedative, analgesia and anti-anxiety effects, it has little impact on the respiration. OBJECTIVE:To observe the analgesic effect induced by intrathecal injection of dexmedetomidine in rat model of spared nerve injury. METHODS:A total of 60 male Sprague-Dawley rats were randomly divided into three groups (n=12):normal control group, dexmedetomidine group and saline group. Except for the normal control group, spared nerve injury model was established in the rats of dexmedetomidine group and saline group. Dexmedetomidine group was treated with intrathecal injection of dexmedetomidine 3μg/kg every day within 14 days after injury. Saline group was given equal volume of saline for 14 days. The thermal withdrawal latency and mechanical withdrawal threshold were measured respectively before injury, after injury, before injection, and 2, 7, 14 days after intrathecal injection. Four rats were sacrificed in each group at day 2, 7 and 14 after injection, and the lumbar segments (L 4-6 Hematoxylin-eosin staining was performed to detect the morphology of the spinal dorsal horn neurons and ) of the spinal cord were removed. Real-time RT-PCR and western blot analysis were used to determine the expression of protein kinase C mRNA and protein in the spinal dorsal horn neurons. immunohistochemistry staining was carried out to assess the expression level and distribution of protein kinase C. RESULTS AND CONCLUSION:The thermal withdrawal latency and mechanical withdrawal threshold in dexmedetomidine group and saline group were significantly decreased compared with normal control group before or after injection (P  目的:观察鞘内注射右美托咪定对坐骨神经分支选择性损伤模型大鼠的镇痛作用。  方法:雄性SD大鼠60只,随机均分为3组。除正常对照组外,另2组大鼠建立坐骨神经分支选择性损伤模型,

  13. Effect of activation of γ-aminobutyric acid B receptors on glutamate release in spinal dorsal horn neurons in rats with diabetic neuropathic pain%激活γ-氨基丁酸B受体对糖尿病神经痛大鼠脊髓背角神经元谷氨酸递质释放的影响

    Institute of Scientific and Technical Information of China (English)

    王秀丽; 吴川; 郭跃先; 王秋筠; 刘飞飞; 曹倩倩; 张兆龙

    2012-01-01

    release in spinal dorsal horn neurons in rats with diabetic neuropathyic pain(DNP). Methods Thirty Sprague-Dawley(SD) male rats(aged 4 weeks,weighing 150 g-170 g) were randomly divided into 2 groups (n=15):Normal rats group (N group),DN rats group (D group).DNP were induced by single intraperitoneal (IP) injection of streptozotocin (STZ,50 mg/kg),and rats in C group received the equal volume saline injection.At 3-4 weeks after STZ or saline intraperitoneal injection,blood glucose level and paw withdraw threshold (PWT) were measured,and the rats were then killed,the lumbar segment of spinal cord (L1-5) was removed for slices preparations.Monosynaptic glutamatergic evoked excitatory postsynaptic currents (eEPSCs) of lamina Ⅱ neurons were recorded by using whole-cell voltage-clamp patch.Bath baclofen (1,10,20,50 μmol/L) was applicated,monosynaptic eEPSCs was recorded before application of baclofen,at 1,10,20,50 μmol/L and wash out 5 min,the inhibitory rate (%) of eEPSCs was compared between two groups (n=15),the effect of CGP55845 (1 pmol/L) on eEPSCs of 50 μmol/L baclofen was analyzed in two groups (n=12). Results The mean blood glucose level was significantly higher in D group than in N group,while PWT in D group was significantly lower than that in N group (P<0.05).eEPSCs in totally 30 glutamatergic neurons was recorded by electrophysiological recording. (1, 10,20,50 μmol/L) baclofen dose-dependently decreased the amplitude of eEPSCs both in two groups,the significant decrease of the amplitude inhibitory rate (%) of eEPSCs was observed at 1,10,20,50 μmol/L baclofen both in two groups(P<0.05),its in D group were significantly decreased compared with N group at above times(P<0.05) respectively:(47±7) vs (21 ±7 ),(55 ±6) vs (50±6),(92±6) vs (72±9),(95 ±8) vs (88±8).CGP55845 was completely abolished the inhibitory effect of 50 μmol/L baclofen on the amplitude of monosynaptic eEPSCs in lamina Ⅱ neurons both two groups. Conclusions Activation of

  14. The effect of botulinum neurotoxin A on sciatic nerve injury-induced neuroimmunological changes in rat dorsal root ganglia and spinal cord.

    Science.gov (United States)

    Mika, J; Rojewska, E; Makuch, W; Korostynski, M; Luvisetto, S; Marinelli, S; Pavone, F; Przewlocka, B

    2011-02-23

    Botulinum neurotoxin serotype A (BoNT/A) acts by cleaving synaptosome-associated-protein-25 (SNAP-25) in nerve terminals to inhibit neuronal release and shows long-lasting antinociceptive action in neuropathic pain. However, its precise mechanism of action remains unclear. Our study aimed to characterize BoNT/A-induced neuroimmunological changes after chronic constriction injury (CCI) of the sciatic nerve. In the ipsilateral lumbar spinal cords of CCI-exposed rats, the mRNA of microglial marker (complement component 1q, C1q), astroglial marker (glial fibrillary acidic protein, GFAP), and prodynorphin were upregulated, as measured by reverse transcription-polymerase chain reaction (RT-PCR). No changes appeared in mRNA for proenkephalin, pronociceptin, or neuronal and inducible nitric oxide synthase (NOS1 and NOS2, respectively). In the dorsal root ganglia (DRG), an ipsilateral upregulation of prodynorphin, pronociceptin, C1q, GFAP, NOS1 and NOS2 mRNA and a downregulation of proenkephalin mRNA were observed. A single intraplantar BoNT/A (75 pg/paw) injection induced long-lasting antinociception in this model. BoNT/A diminished the injury-induced ipsilateral spinal upregulation of C1q mRNA. In the ipsilateral DRG a significant decrease of C1q-positive cell activation and of the upregulation of prodynorphin, pronociceptin and NOS1 mRNA was also observed following BoNT/A admistration. BoNT/A also diminished the injury-induced upregulation of SNAP-25 expression in both structures. We provide evidence that BoNT/A impedes injury-activated neuronal function in structures distant from the injection site, which is demonstrated by its influence on NOS1, prodynorphin and pronociceptin mRNA levels in the DRG. Moreover, the silence of microglia/macrophages after BoNT/A administration could be secondary to the inhibition of neuronal activity, but this decrease in neuroimmune interactions could be the key to the long-lasting BoNT/A effect on neuropathic pain.

  15. Hypericum perforatum Attenuates Spinal Cord Injury-Induced Oxidative Stress and Apoptosis in the Dorsal Root Ganglion of Rats: Involvement of TRPM2 and TRPV1 Channels.

    Science.gov (United States)

    Özdemir, Ümit Sinan; Nazıroğlu, Mustafa; Şenol, Nilgün; Ghazizadeh, Vahid

    2016-08-01

    Oxidative stress and cytosolic Ca(2+) overload have important roles on apoptosis in dorsal root ganglion (DRG) neurons after spinal cord injury (SCI). Hypericum perforatum (HP) has an antioxidant property in the DRGs due to its ability to modulate NADPH oxidase and protein kinase C pathways. We aimed to investigate the protective property of HP on oxidative stress, apoptosis, and Ca(2+) entry through transient receptor potential melastatin 2 (TRPM2) and transient receptor potential vanilloid 1 (TRPV1) channels in SCI-induced DRG neurons of rats. Rats were divided into four groups as control, HP, SCI, and SCI + HP. The HP groups received 30 mg/kg HP for three concessive days after SCI induction. The SCI-induced TRPM2 and TRPV1 currents and cytosolic free Ca(2+) concentration were reduced by HP. The SCI-induced decrease in glutathione peroxidase and cell viability values were ameliorated by HP treatment, and the SCI-induced increase in apoptosis, caspase 3, caspase 9, cytosolic reactive oxygen species (ROS) production, and mitochondrial membrane depolarization values in DRG of SCI group were overcome by HP treatment. In conclusion, we observed a protective role of HP on SCI-induced oxidative stress, apoptosis, and Ca(2+) entry through TRPM2 and TRPV1 in the DRG neurons. Our findings may be relevant to the etiology and treatment of SCI by HP. Graphical Abstract Possible molecular pathways of involvement of Hypericum perforatum (HP) on apoptosis, oxidative stress, and calcium accumulation through TRPM2 and TRPV1 channels in DRG neurons of SCI-induced rats. The TRPM2 channel is activated by ADP-ribose and oxidative stress through activation of ADP-ribose pyrophosphate although it was inhibited by N-(p-amylcinnamoyl) anthranilic acid (ACA) and 2-aminoethyl diphenylborinate (2APB). The TRPV1 channel is activated by oxidative stress and capsaicin and it is blocked by capsazepine. Injury in the DRG can result in augmented ROS release, leading to Ca(2+) uptake through

  16. Effects of gabapentin combined with morphine on expression of glial fibillary acid protein of spinal dorsal horn in rats with neuropathic pain%加巴喷丁联合吗啡对神经病理性疼痛大鼠脊髓胶质原纤维酸性蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    刘红; 万朝权; 田可耘; 梅莉; 崔灿; 张晓晨

    2012-01-01

    目的:观察加巴喷丁联合吗啡镇痛对坐骨神经慢性压迫(CCI)大鼠脊髓背角胶质原纤维酸性蛋白(GFAP)表达的影响.方法:选择重量在180~220 g的成年雄性SD大鼠24只,随机分为4组(n=6):假手术组(S组)、模型组(M组)、预防性镇痛组(P组)和常规镇痛组(N组).M组、P组和N组采用CCI建立神经病理性疼痛模型,P组在术前1 d至手术后9 d使用加巴喷丁联合吗啡镇痛,N组在手术当日至手术后第9天加巴喷丁联合吗啡镇痛,S组和M组仅给予生理盐水.分别于手术后第3、5、7、9天测定各组50%机械刺激缩足阈值,手术后第10天采用免疫组化测定脊髓GFAP表达.结果:与M组相比,P组和N组50%缩足阈值升高,同时脊髓背角GFAP表达降低(M组:0.623 7±0.049 03,P组:0.461 6±0.038 90,N组:0.521 5±0.026 91).结论:加巴喷丁联合吗啡可以减轻CCI神经病理性疼痛和脊髓背角GFAP的表达.%Objective To observe the effects of gabapentin combined with morphine on expression of glial fibillary acid protein (GFAP) of spinal dorsal horn in rats model of chronic constriction injury (CCI) to sciatic nerve. Methods Twenty four male Sprague-Dawley rats were randomly divided into sham operation group (group S), model group (group M), preventive analgesia group (group P) and normal analgesia group (group N), and were subjected to CCI (group M, P, N) or sham surgery (group S). Gabapentin combined with morphine were given from pre-operative day 1 to postoperative day 9 in group P, and in group N they were given from operative day to postoperative day 9. The group M and group S were given normal saline. Mechanical withdraw threshold of the rats were measured with Von Frey hair on pre-operative day 1 and postoperative day 3, 5, 7, 9 respectively. The expression of GFAP in spinal dorsal horn was assessed by immunohistochemistry at postoperative day 10. Results After operation, mechanical withdraw threshold decreased markedly in group M. Compared

  17. 姜黄素对2型糖尿病大鼠神经病理性痛及脊髓背角和背根神经节IRE1α表达的影响%Effects of curcumin on type 2 diabetic neuropathic pain and expression of inositol-requiring enzyme 1α in spinal dorsal horn and dorsal root ganglia in rats

    Institute of Scientific and Technical Information of China (English)

    党江坤; 汪小丹; 周林; 曹红; 吴艳; 李军; 连庆泉

    2012-01-01

    目的 评价姜黄素对2型糖尿病大鼠神经病理性痛及脊髓背角和背根神经节肌醇需求激酶1α(IRE1α)表达的影响.方法 高脂高糖喂养雄性SD大鼠8周诱导胰岛素抵抗,以35 mg/kg链脲佐菌素(STZ)单次腹腔注射,3d后血糖≥16.7 mmol/L大鼠为2型糖尿病大鼠.注射STZ 14 d后机械缩足阈值(MWT)和热缩足潜伏期(TWL)低于基础值80%的大鼠为2型糖尿病神经病理性痛大鼠,采用随机数字表法,将其随机分为3组(n=27):2型糖尿病神经病理性痛组(DNP组)、姜黄素组(Cur组)和溶剂对照组(SC组).Cur组和SC组于注射STZ 14 d后腹腔注射姜黄素或玉米油100 mg/kg(25mg/ml),1次/d,连续14d,DNP组不做任何处理.另取27只正常大鼠为对照组(C组),给予普通饲料喂养.给予姜黄素后第3、7和14天时测定MWT和TWL,痛阈测定后用Western blot法检测大鼠脊髓背角和背根神经节IREIα的表达.结果 与C组比较、DNP组、Cur组和SC组MWT降低,TWL缩短,脊髓背角和背根神经节IRE1α表达上H调(P<0.05);与DNP组比较,Cur组MWT升高,TWL延长,脊髓背角和背根神经节IREIα表达下调(p<0.05).SC组和DNP组上述指标比较差异无统计学意义(P>0.05).结论 姜黄素可减轻2型糖尿病大鼠神经病理性痛,其机制与抑制脊髓背角和背根神经节IRE1α表达有关.%Objective To investigate the effects of curcumin on type 2 diabetic neuropathic pain (DNP)and expression of inositol-requiring enzyme 1α (IRE1α) in spinal dorsal horn and dorsal root ganglia (DRG) in rats.Methods Type 2 diabetes mellitus was induced by high-fat and high-sucrose diet and intraperitoneal streptozotocin (STZ) 35 mg/kg,and confirmed by fasting blood glucose level > 16.7 mmol/L in male SD rats.Type 2 DNP was confirmed by the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWI.) measured on day 14 after STZ administration < 80% of the baseline value.The rats were then randomly divided into 3

  18. Paclitaxel-induced peripheral neuropathy increases substance P release in rat spinal cord.

    Science.gov (United States)

    Chiba, Terumasa; Oka, Yusuke; Kambe, Toshie; Koizumi, Naoya; Abe, Kenji; Kawakami, Kazuyoshi; Utsunomiya, Iku; Taguchi, Kyoji

    2016-01-05

    Peripheral neuropathy is a common adverse effect of paclitaxel treatment. The major dose-limiting side effect of paclitaxel is peripheral sensory neuropathy, which is characterized by painful paresthesia of the hands and feet. To analyze the contribution of substance P to the development of paclitaxel-induced mechanical hyperalgesia, substance P expression in the superficial layers of the rat spinal dorsal horn was analyzed after paclitaxel treatment. Behavioral assessment using the von Frey test and the paw thermal test showed that intraperitoneal administration of 2 and 4mg/kg paclitaxel induced mechanical allodynia/hyperalgesia and thermal hyperalgesia 7 and 14 days after treatment. Immunohistochemistry showed that paclitaxel (4mg/kg) treatment significantly increased substance P expression (37.6±3.7% on day 7, 43.6±4.6% on day 14) in the superficial layers of the spinal dorsal horn, whereas calcitonin gene-related peptide (CGRP) expression was unchanged. Moreover, paclitaxel (2 and 4mg/kg) treatment significantly increased substance P release in the spinal cord on day 14. These results suggest that paclitaxel treatment increases release of substance P, but not CGRP in the superficial layers of the spinal dorsal horn and may contribute to paclitaxel-induced painful peripheral neuropathy.

  19. Expression of nitric oxide synthase in the spinal cord after selective brachial plexus injury

    Institute of Scientific and Technical Information of China (English)

    Na Liu; Feng Li; Longju Chen; Wutian Wu

    2006-01-01

    BACKGROUND: Some researches showed that motoneurons in spinal cord anterior horn wound die following brachial plexus injury, but the concrete mechanism of motoneurons death remains unclear.OBJECTIVE: To observe the expression of nitric oxide synthase (NOS) and survival of C7 motoneurons in spinal cord of rats after selective brachial plexus injury.DESIGN: A randomized controlled animal experiment.SETTING: Department of Anatomy, Sun Yet-sen Medical College, Sun Yet-sen University.MATERIALS: Totally 35 adult healthy male Sprague-Dawley rats with the body mass of 200-300 g were provided by Experimental Animal Center, Sun Yet-sen Medical College, Sun Yat-sen University. The rats were divided into control group (n =5) and experimental group (n=30) by random number table method, and the experimental group was divided into three injury subgroups: anterior root avulsion group, dorsal root transection group and spinal cord hemisection group, 10 rats in each group. There were horse anti-neuronal NOS (Nnos) polycolonal antibody (Sigma company) and nicotina mideadeninedinucleotide phosphate (NADPH-d) (SigmaCompany).METHODS: The experiment was performed at Department of Anatomy, Sun Yet-sen Medical College, Sun Yet-sen University between September 2004 and April 2005. ①After anesthetizing the rats, the spinous process of second thoracic vertebra as a marker, the vertebra was exposed from C5 to T1 and the lamina of vertebra was unclenched, and spinal dura mater was carved to expose the spinal nerve dorsal roots of C5-T1.The right ventral root of C7 was avulsed, and the residual root was removed in anterior root avulsion group. The right ventral root of C7 was avulsed and the right dorsal roots of brachial plexus (C5-T1) were cut off in dorsal root transection group. In spinal cord hemisection group, the hemisection between the C5 and C6 spinal segment on right side and avulsion of right ventral root of C7 were made. In the control group, the vertebra from C5 to T1 was

  20. Accumulation of Misfolded SOD1 in Dorsal Root Ganglion Degenerating Proprioceptive Sensory Neurons of Transgenic Mice with Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Javier Sábado

    2014-01-01

    Full Text Available Amyotrophic lateral sclerosis (ALS is an adult-onset progressive neurodegenerative disease affecting upper and lower motoneurons (MNs. Although the motor phenotype is a hallmark for ALS, there is increasing evidence that systems other than the efferent MN system can be involved. Mutations of superoxide dismutase 1 (SOD1 gene cause a proportion of familial forms of this disease. Misfolding and aggregation of mutant SOD1 exert neurotoxicity in a noncell autonomous manner, as evidenced in studies using transgenic mouse models. Here, we used the SOD1G93A mouse model for ALS to detect, by means of conformational-specific anti-SOD1 antibodies, whether misfolded SOD1-mediated neurotoxicity extended to neuronal types other than MNs. We report that large dorsal root ganglion (DRG proprioceptive neurons accumulate misfolded SOD1 and suffer a degenerative process involving the inflammatory recruitment of macrophagic cells. Degenerating sensory axons were also detected in association with activated microglial cells in the spinal cord dorsal horn of diseased animals. As large proprioceptive DRG neurons project monosynaptically to ventral horn MNs, we hypothesise that a prion-like mechanism may be responsible for the transsynaptic propagation of SOD1 misfolding from ventral horn MNs to DRG sensory neurons.

  1. 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.

  2. Label-free imaging of rat spinal cords based on multiphoton microscopy

    Science.gov (United States)

    Liao, Chenxi; Wang, Zhenyu; Zhou, Linquan; Zhu, Xiaoqin; Liu, Wenge; Chen, Jianxin

    2016-10-01

    As an integral part of the central nervous system, the spinal cord is a communication cable between the body and the brain. It mainly contains neurons, glial cells, nerve fibers and fiber tracts. The recent development of the optical imaging technique allows high-resolution imaging of biological tissues with the great potential for non-invasively looking inside the body. In this work, we evaluate the imaging capacity of multiphoton microscopy (MPM) based on second harmonic generation (SHG) and two-photon excited fluorescence (TPEF) for the cells and extracellular matrix in the spinal cord at molecular level. Rat spinal cord tissues were sectioned and imaged by MPM to demonstrate that MPM is able to show the microstructure including white matter, gray matter, ventral horns, dorsal horns, and axons based on the distinct intrinsic sources in each region of spinal cord. In the high-resolution and high-contrast MPM images, the cell profile can be clearly identified as dark shadows caused by nuclei and encircled by cytoplasm. The nerve fibers in white matter region emitted both SHG and TPEF signals. The multiphoton microscopic imaging technique proves to be a fast and effective tool for label-free imaging spinal cord tissues, based on endogenous signals in biological tissue. It has the potential to extend this optical technique to clinical study, where the rapid and damage-free imaging is needed.

  3. Pannexin 1: a novel participant in neuropathic pain signaling in the rat spinal cord.

    Science.gov (United States)

    Bravo, David; Ibarra, Paula; Retamal, Jeffri; Pelissier, Teresa; Laurido, Claudio; Hernandez, Alejandro; Constandil, Luis

    2014-10-01

    Pannexin 1 (panx1) is a large-pore membrane channel expressed in many tissues of mammals, including neurons and glial cells. Panx1 channels are highly permeable to calcium and adenosine triphosphatase (ATP); on the other hand, they can be opened by ATP and glutamate, two crucial molecules for acute and chronic pain signaling in the spinal cord dorsal horn, thus suggesting that panx1 could be a key component for the generation of central sensitization during persistent pain. In this study, we examined the effect of three panx1 blockers, namely, 10panx peptide, carbenoxolone, and probenecid, on C-reflex wind-up activity and mechanical nociceptive behavior in a spared nerve injury neuropathic rat model involving sural nerve transection. In addition, the expression of panx1 protein in the dorsal horn of the ipsilateral lumbar spinal cord was measured in sural nerve-transected and sham-operated control rats. Sural nerve transection resulted in a lower threshold for C-reflex activation by electric stimulation of the injured hindpaw, together with persistent mechanical hypersensitivity to pressure stimuli applied to the paw. Intrathecal administration of the panx1 blockers significantly depressed the spinal C-reflex wind-up activity in both neuropathic and sham control rats, and decreased mechanical hyperalgesia in neuropathic rats without affecting the nociceptive threshold in sham animals. Western blotting showed that panx1 was similarly expressed in the dorsal horn of lumbar spinal cord from neuropathic and sham rats. The present results constitute the first evidence that panx1 channels play a significant role in the mechanisms underlying central sensitization in neuropathic pain. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  4. Sulfide silver architectonics of rat, cat, and guinea pig spinal cord. A light microscopic study with Timm's method for demonstration of heavy metals

    DEFF Research Database (Denmark)

    Schroder, H D

    1977-01-01

    The distribution of heavy metals in the spinal cord of the cat, rat, and guinea pig has been studied histochemically with Timm's sulfide silver method. There was considerable variation in the degree of staining of the neuropil. The dorsal horn showed a laminar staining pattern corresponding...... to the cytoarchitectonic lamination. Lamina I in the cat and guinea pig was light. Lamina II in all three species was heavily stained. In the rat and guinea pig it could be subdivided in a ventral and a dorsal layer, and moreover in the rat a darkly staining borderzone abutting on lamina III was present. Lamina III......, characterized by heterogeneous staining, also appeared dark, although less obvious in the guinea pig. In the ventral horn the coarser stained particles in lamina IX contrasted with the surrounding lamina. Cell staining varied between different cell groups, and within single cell populations. In the cat thoracic...

  5. Effects of electroacupuncture on expression of c-fos protein in the spinal dorsal horn of rats with chronic visceral hyperalgesia%电针对慢性内脏痛敏大鼠脊髓背角c-fos蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    祁德波; 李为民

    2012-01-01

    OBJECTIVE:Acupuncture is widely used in clinics to suppress chronic visceral pain in patients with irritable bowel syndrome (IBS); however,the exact neurobiological mechanisms for its therapeutic effects need further exploration.The aim of this study was to investigate the possible involvement of spinal neurons in the effects of electroacupuncture (EA) in relieving chronic visceral hyperalgesia in a rat model of IBS.METHODS:Colon mechanical irritation was applied to male neonatal Sprague-Dawley rats to establish the IBS model.Behavioral test of the abdominal withdraw reflex (AWR) response to colorectal distention stimuli was conducted to judge the degree of colorectal sensitivity.EA at acupoints Zusanli (ST36) and Shangjuxu (ST37) was applied bilaterally in a total of four times every other day,while sham-EA at similar acupoints was done by inserting needles without electrical stimulation.Immunohistochemical methods were used to display the expression of proto-oncogene protein c-fos in the spinal dorsal horn.RESULTS:It was found that AWR scores were significantly increased in the IBS model rats (P<0.01),accompanied with significant increase in the expression of c-fos protein in the superficial laminae (SDH,laminae Ⅰ and Ⅱ) and nucleus proprius (NP,laminae Ⅲ and Ⅳ),the neck of the dorsal horn (NECK,laminae V and Ⅵ) at lumbosacral (L6-S2) spinal level,and in NECK at thoracolumbar (T13-L2) spinal level,when compared with normal rats (P<0.05).After EA treatment,AWR scores and the expression of c-fos protein in SDH,NP and NECK at similar spinal levels were significantly decreased in the IBS model rats (P<0.05).No such effects on either AWR scores or the expression of c-fos protein were observed in IBS model rats after sham-EA treatment.CONCLUSION:The abnormally high neuronal excitability in the spinal dorsal horn may be an important reason underlying the visceral hyperalgesia in IBS model rats.EA treatment can relieve the chronic visceral hyperalgesia in

  6. Activity correlations between on-like and off-like cells of the rostral ventromedial medulla and simultaneously recorded wide-dynamic-range neurons of the spinal dorsal horn in rats.

    Science.gov (United States)

    Salas, Rafael; Ramirez, Karla; Vanegas, Horacio; Vazquez, Enrique

    2016-12-01

    Considerable evidence supports the notion that on- and off-cells of the rostral ventromedial medulla (RVM) facilitate and depress, respectively, spinal nociceptive transmission. This notion stems from a covariation of on- or off-cell activities and spinal nocifensive reflexes. Such covariation could theoretically be due to their independently responding to a common source, or to an RVM-derived modulation of ventral horn neurons. Here, we tested whether on- and off-cells indeed modulate spinal nociceptive neurons. In deeply anesthetized rats, unitary recordings were simultaneously made from an RVM on-like or off-like cell and a spinal nociceptive neuron that shared a receptive field (RF) at a hind paw. Action potential firing in RVM/spinal neuron pairs was highly correlated, positively for on-like cells and negatively for off-like cells, both during ongoing activity and during application of calibrated noxious pressure to the RF. Microinjection of morphine into RVM induced a correlated decrease in on-like cell/spinal neuron ongoing activity and response to noxious stimulation. RVM morphine induced changes in off-like cell activity that were not correlated with spinal neuronal activity. These results suggest that on-cells exert a positive modulation upon spinal nociceptive neurons, upstream to ventral horn circuits and plausibly at the origin of nociceptive information that eventually reaches the cerebral cortex. On-cells may in this manner contribute to inflammation- and neuropathy-induced increases in withdrawal reflexes. Most significantly, on-cell modulation of nociceptive neurons may be a key factor in clinical pain conditions such as hyperalgesia and allodynia.

  7. The expression of Lingo-1 after thoracic spinal cord dorsal laceration in mice%小鼠胸段脊髓背横切后Lingo-1的表达变化

    Institute of Scientific and Technical Information of China (English)

    顾振; 丁小丽; 左国平; 张永杰

    2012-01-01

    Objective To explore the dynamic expression of Lingo-1 after spinal cord dorsal laceration in the mice. Methods LISA (Louisville Injury Systems Apparatus) was used to generate a precise 9th thoracic dorsal laceration with the lesion depth of 1.1mm in the mice. Real time RT-PCR and Western Blot were applied to access the expression levels of Lingo-1 mRNA and protein at 1 , 3 , 7, 14, and 28 days post-injury. Results The expression levels of Lingo-1 mRNA and protein were significantly up-regulated at 1 day and reached the peak value at 7 days post-surgery. The up-regulation of Lingo-1 mRNA lasted to the 14 days and the up-regulation of Lingo-1 protein lasted to the 28 days post-surgery compared to the normal controls. Conclusion These results showed the higher expression of Lingo-1 after dorsal spinal cord laceration and suggested which was involved in the axonal degeneration after spinal cord injury (SCI). The early and sustained usage of Lingo-1 antagonist was suggested to promote the axonal regeneration after SCI.%目的 观察Lingo-1在小鼠脊髓背侧切割伤后不同时间窗的动态表达变化.方法 采用LISA脊髓损伤仪制作小鼠第9胸髓背侧切割伤模型(深度1.1 mm),运用Real time RT-PCR和Western blot观察Lingo-l mRNA和蛋白在术后1、3、7、14、28 d的表达变化.结果 Lingo-1 mRNA和蛋白的表达在小鼠脊髓背侧切割伤后1d即显著上调,7d时达高峰,并持续上调表达至术后2~4周.结论 Lingo-1在脊髓切割伤后表达上调,揭示其与脊髓损伤后轴突变性有关;对于治疗脊髓损伤促进轴突再生,Lingo-1拮抗剂应在损伤早期即开始并持续使用.

  8. The influence of GABAB receptor expression in the spinal dorsal horn of rats by using baclofen in combination with morphine%巴氯芬与吗啡联合应用对脊髓背角GABAB受体表达的影响

    Institute of Scientific and Technical Information of China (English)

    单文燕; 陈艳平; 曹德权

    2012-01-01

    目的 探讨巴氯芬与吗啡联合应用对脊髓背角GABAB受体表达的影响.方法 成年雄性SD大鼠48只鞘内置管成功后,随机均分为四组,分别鞘内注射生理盐水10μl(NS组),吗啡10μg(M组),巴氯芬0.5μg(B组)和巴氯芬0.5μg+吗啡10 μg(BM组).每天9:00和16:00鞘内注射,在9:30行热水浴甩尾潜伏期(TFL)测定,连测3次,间隔5 min,取其均值,将第1天注药后的TFL均值作为基础值,以TFL恢复到基础值作为出现吗啡耐受的标准.第11天晨,取大鼠腰段脊髓行免疫组织化学染色观察脊髓背角GABAB受体的表达.结果 注药后第10天M组大鼠TFL恢复至基础值,出现吗啡耐受现象,B组和BM组未出现吗啡耐受现象(P<0.01).M组GABABR1及GABABR2表达明显低于其它三组(P<0.01).结论 巴氯芬与吗啡联合应用可以减轻吗啡对脊髓背角GABAB受体表达的下调作用.%Objective To investigate the effects of GABAB receptor expression in the spinal dorsal horn of rats by using baclofen in combination with morphine. Methods Healthy male SD rats were randomly divided into four groups after the success of intrathecal cathetemation (n=12). They included saline group(group NS): 0. 9% saline 10 /μ∣, morphine group(group M). morphine 10 figs baclofen group(group B): baclofen 0. 5 μg, baclofen-morphine group (group BM): baclofen 0. 5 μg +morphine 10 μg. Drugs were given by intrathecal injection on 9:00 am and 16:00 pm for 10 consecutive days. At 9:30 the tail-flick latency (TFL) in rats were measured continued 3 limes with an interval of 5 mm. The mean value of TFL measured on the first day were considered as the baseline, and the return to baseline level of TFL were regarded as the morphine tolerance standard. In the morning of the eleventh day, spinal lumbar enlargement of rats were removed and cut into frozen sections to test GABAB receptors expression by immunohistochemical staining. Results TFL of rats returned to baseline in group M after 10 days

  9. The expression of BDNF and TrkB in the spinal dorsal horn of the asthmatic mice%哮喘小鼠C7~T5节段脊髓后角BDNF及其受体TrkB的表达研究

    Institute of Scientific and Technical Information of China (English)

    张宝辉; 方秀斌; 刘晓湘

    2013-01-01

    Objective To study the expression of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor tyrosine kinase receptor B (TrkB) in the spinal dorsal horn of the asthmatic mice. Methods 20 BALB/c mice were randomly divided into normal control group and asthmatic group. The airway resistance of mice was measured with AniRes 2005 pulmonary function meter; The expressions of BDNF and TrkB were observed by immunofluorescence and western blot methods of all the groups. Results Inspiratory resistance and expiratory resistance in the asthmatic mice were obviously higher than in normal control mice, the asthmatic model was successfully constructed. The mean optic density (MOD) of BDNF and TrkB positive product in the C7-T5 spinal dorsal horn increased significantly in the asthmatic mice than in normal control by means of immunofluorescence (P<0.01), and the same result was obtain by western blot method. Conclusion The expressions of BDNF and TrkB were elevated in the C7-T5 spinal dorsal horn of the asthmatic mice.%目的 探讨在哮喘发病中,脑源性神经营养因子(BDNF)及其高亲和力受体酪氨酸激酶B(TrkB)在哮喘小鼠C7~T5节段脊髓后角内的表达变化.方法 BALB/c小鼠20只,按随机数字表法均分为正常对照组和哮喘组,利用AniRes2005肺功能仪测小鼠气道阻力、免疫荧光方法和Western blot方法检测各组小鼠C7~T5节段脊髓后角内BDNF及其高亲和力受体TrkB的表达变化.结果 哮喘组小鼠吸气阻力和呼气阻力明显高于正常组(P<0.01),哮喘模型建立成功.免疫荧光结果显示哮喘组C7~T5节段脊髓后角内BDNF及TrkB阳性产物的平均光密度值(MOD)显著高于正常对照组(P<0.01),Western blot方法检测也得到了相同的结果.结论 哮喘小鼠C7~T5节段脊髓后角内BDNF及TrkB的表达升高.

  10. 瑞芬太尼诱导大鼠脊髓背角痛觉过敏及利多卡因的抑制作用%Remifentanil-induced hyperalgesia in spinal dorsal horn and the inhibition of lidocaine in rats

    Institute of Scientific and Technical Information of China (English)

    崔伟华; 谭红; 韩如泉; 李树人; 李俊发

    2011-01-01

    Objective To determine the involvement of conventional protein kinase Cgamma (cPKCγ) in the inhibitory action of lidocaine on remifentanil-induced hyperalgesia of rats after propofol-remifentanil-based anesthesia.Methods Male Sprague-Dawley rats were allocated into the following groups randomly: propofol only (group P),propofol + remifentanil ( group R), propofol + remifentanil + lidocaine ( group RL), and propofol + lidocaine (group L). Cumulative pain score and withdrawal response to mechanical stimulation, immunoblotting, and immunofluorescence were applied to observe remifentanil-induced hyperalgesia and cPKCγ membrane translocation.Results (1)Cumulative pain score in group R was higher than that in other groups on postanesthesia 120 min (P < 0. 05 ). While it were similar among group P, RL and L. (2) Withdrawal threshold on the ipsilateral side to incised plantar in group R were lower than the other groups ( P < 0. 05) on postanesthesia 120 min. ( 3 ) Both immunoblotting and immunofluorescence demonstrated that the membrane translocation of PKCγ in dorsal horn neurons increased in propofol-remifentanil anesthetized animals and systemic lidocaine inhibited it. Surgery procedure won't affect the membrane translocation of PKCγin dorsal horn neurons shortly after anesthesia. Conclusion Increased PKCγmembrane translocation in spinal dorsal horn involves in remffentanil-induced hyperalgesia, which was inhibited by systemic lidocaine and may contributes to reduction of postoperative pain in rats after remifentanilbased anesthesia.%目的 探讨大鼠脊髓背角细胞蛋白激酶Cγ(PKCγ)膜转位/激活在瑞芬太尼诱导痛觉过敏中的作用及利多卡因的抑制作用.方法 将大鼠随机分为4组:(1)丙泊酚组(P组),(2)瑞芬太尼组(R组),(3)瑞芬太尼-利多卡因组(RL组)及(4)利多卡因组(L组).比较4组麻醉后累积疼痛评分和机械性刺激缩足阈值.用免疫印迹(每组n=8)和免疫荧光法测量脊髓

  11. Peripheral injury of pelvic visceral sensory nerves alters GFRa (GDNF family receptor alpha localization in sensory and autonomic pathways of the sacral spinal cord

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    Shelley Lynne Forrest

    2015-04-01

    Full Text Available GDNF (glial cell line-derived neurotrophic factor, neurturin and artemin use their co-receptors (GFRα1, GFRα2 and GFRα3, respectively and the tyrosine kinase Ret for downstream signalling. In rodent dorsal root ganglia (DRG most of the unmyelinated and some myelinated sensory afferents express at least one GFRα. The adult function of these receptors is not completely elucidated but their activity after peripheral nerve injury can facilitate peripheral and central axonal regeneration, recovery of sensation, and sensory hypersensitivity that contributes to pain. Our previous immunohistochemical studies of spinal cord and sciatic nerve injuries in adult rodents have identified characteristic changes in GFRα1, GFRα2 or GFRα3 in central spinal cord axons of sensory neurons located in dorsal root ganglia. Here we extend and contrast this analysis by studying injuries of the pelvic and hypogastric nerves that contain the majority of sensory axons projecting to the pelvic viscera (e.g., bladder and lower bowel. At 7 d, we detected some effects of pelvic but not hypogastric nerve transection on the ipsilateral spinal cord. In sacral (L6-S1 cord ipsilateral to nerve injury, GFRα1-immunoreactivity (IR was increased in medial dorsal horn and CGRP-IR was decreased in lateral dorsal horn. Pelvic nerve injury also upregulated GFRα1- and GFRα3-IR terminals and GFRα1-IR neuronal cell bodies in the sacral parasympathetic nucleus that provides the spinal parasympathetic preganglionic output to the pelvic nerve. This evidence suggests peripheral axotomy has different effects on somatic and visceral sensory input to the spinal cord, and identifies sensory-autonomic interactions as a possible site of post-injury regulation.

  12. 氯胺酮对N-甲基-D-天冬氨酸诱导大鼠脊髓背角星形胶质细胞损伤的作用%Influence of ketamine on astrocyte damage in spinal dorsal horn of rats induced by N-methyl-D-aspartic acid

    Institute of Scientific and Technical Information of China (English)

    李清; 刘菊英; 周青山; 朱涛; 秦成名

    2006-01-01

    组,差异显著[分别为(25.26±6.13)%,(5.66±2.24)%,P<0.01],100μmol/LN-甲基-D-天冬氨酸+1 mmol/L氯胺酮组低于100 μmol/L N-甲基-D-天冬氨酸组,差异显著[分别为(24.41±4.82)%,(25.26±6.13)%,P<0.01].③丙二醛含量和超氧化物歧化酶活性变化:100 μmol/L N-甲基-D-天冬氨酸使星形胶质细胞内丙二醛含量显著升高,而超氧化物歧化酶活性明显降低;1 mmol/L氯胺酮明显降低丙二醛含量,显著增强超氧化物歧化酶活性,该效应在临床镇痛剂量以内有明显量效关系,与N-甲基-D-天冬氨酸组相比差异显著(P<0.01).1 mmol/L氯胺酮组与对照组相比、100μmol/L N-甲基-D-天冬氨酸+0.1 mmol/L氯胺酮组与N-甲基-D-天冬氨酸组相比差异均无显著性.结论:N-甲基-D-天冬氨酸受体过度激活可诱导大鼠脊髓背角星形胶质细胞大量凋亡,适量氯胺酮显著抑制细胞凋亡,其机制可能增强星形胶质细胞Bcl-2蛋白表达,同时抑制自由基的产生和增强超氧化物歧化酶活性.%BACKGROUND: Ketamine is a kind of frequently used general venous anesthesia drug in clinic, and the medication in vein or epidural cavum has analgesic effect. It is N-methyl-D-aspartic acid (NMDA) receptor noncompetitive antagonist, which can inhibit toxic effect of excitatory amino acids.OBJECTIVE: To observe effect of ketamine on apoptosis of dorsal horn astrocytes of spinal cord of rats induced by NMDA receptor over activation and explore its possible mechanism of action.DESIGN: Randomized controlled observation.SETTING: Department of Anesthesiology, Taihe Hospital Affiliated to Yunyang Medical College.MATERIALS: The experiment was conducted at Cell Biology Laboratory,Institute of Basic Medical Sciences, Yunyang Medical College between September 2003 and January 2005. Neonatal Wistar rats of two or three days were provided by Animal Experimental Center of Wuhan University. METHODS: Primary astrocytes in dorsal horn of T11-L6 spinal cord of Wistar rats were purified and

  13. Decreased Endomorphin-2 and μ-Opioid Receptor in the Spinal Cord Are Associated with Painful Diabetic Neuropathy

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    Kou, Zhen-Zhen; Wan, Fa-Ping; Bai, Yang; Li, Chun-Yu; Hu, Jia-Chen; Zhang, Guo-Tao; Zhang, Ting; Chen, Tao; Wang, Ya-Yun; Li, Hui; Li, Yun-Qing

    2016-01-01

    Painful diabetic neuropathy (PDN) is one of the most common complications in the early stage of diabetes mellitus (DM). Endomorphin-2 (EM2) selectively activates the μ-opioid receptor (MOR) and subsequently induces antinociceptive effects in the spinal dorsal horn. However, the effects of EM2-MOR in PDN have not yet been clarified in the spinal dorsal horn. Therefore, we aimed to explore the role of EM2-MOR in the pathogenesis of PDN. The main findings were the following: (1) streptozotocin (STZ)-induced diabetic rats exhibited hyperglycemia, body weight loss and mechanical allodynia; (2) in the spinal dorsal horn, the expression levels of EM2 and MOR decreased in diabetic rats; (3) EM2 protein concentrations decreased in the brain, lumbar spinal cord and cerebrospinal fluid (CSF) in diabetic rats but were unchanged in the plasma; (4) the frequency but not the amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) was significantly higher in diabetic rats than in control rats; and (5) intrathecal injection of EM2 for 14 days in the early stage of PDN partially alleviated mechanical allodynia and reduced MOR expression in diabetic rats. Our results demonstrate that the EM2-MOR signal may be involved in the early stage of PDN. PMID:27656127

  14. Decreased endomorphin-2 and opioidreceptor in the spinal cord are associated with painful diabetic neuropathy

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    Zhen-Zhen Kou

    2016-09-01

    Full Text Available Painful diabetic neuropathy (PDN is one of the most common complications in the early stage of diabetes mellitus (DM. Endomorphin-2 (EM2 selectively activates the opioid receptor (MOR and subsequently induces antinociceptive effects in the spinal dorsal horn. However, the effects of EM2-MOR in PDN have not yet been clarified in the spinal dorsal horn. Therefore, we aimed to explore the role of EM2-MOR in the pathogenesis of PDN. The main findings were the following: (1 streptozotocin (STZ-induced diabetic rats exhibited hyperglycemia, body weight loss and mechanical allodynia; (2 in the spinal dorsal horn, the expression levels of EM2 and MOR decreased in diabetic rats; (3 EM2 protein concentrations decreased in the brain, lumbar spinal cord and CSF in diabetic rats but were unchanged in the plasma; (4 the frequency but not the amplitude of spontaneous excitatory postsynaptic currents (sEPSCs was significantly higher in diabetic rats than in control rats; and (5 intrathecal injection of EM2 for 14 days in the early stage of PDN partially alleviated mechanical allodynia and reduced MOR expression in diabetic rats. Our results demonstrate that the EM2-MOR signal may be involved in the early stage of PDN.

  15. Activation of ERK1/2 in spinal cord contributes to the development of acute cystic pain in rabbits

    Institute of Scientific and Technical Information of China (English)

    Yong-Hong WANG; Li-Cai ZHANG; Yin-Ming ZENG

    2006-01-01

    Objective To investigate the role of activated extracellular signal-regulated kinase 1/2 (ERK1/2) in spinal cord in the development of cystic pain in rabbit. Methods We observed the relationship between the activation of ERK1/2 in spinal cord and nociceptive behaviors, as well as the effect of U0126, a mitogen-activated protein kinase (MEK, upstream protein of ERK1/2) inhibitor, on cystic pain in rabbits by behavioral test, immunohistochemistry and western blot analysis. Results After injecting 0.5 ml formalin into gallbladder, the behaviors such as grasping of the cheek and licking of theabdomen increased in 30 min, with a significant increase in pERK1/2 expression in the spinal cord, as well as the pERK1/2 immunoreactive cells located in laminae Ⅴ~Ⅶ and X of the dorsal horn and ventral horn of T6 spinal cord. Administration of U0126 (100 ~400 μg/kg body weight, i.v., 10 min before instillation of formalin) could attenuated nociceptive behaviors dose-dependently, but could not restrain the nociceptive behaviors completely even at the maximal efficient dose of 400 μg/kg body weight. Conclusion Activated ERK1/2 in the spinal cord at least partly participates in the development of acute inflammatory cystic pain induced by formalin in rabbits.

  16. Anatomical location of Macrophage Migration Inhibitory Factor in urogenital tissues, peripheral ganglia and lumbosacral spinal cord of the rat

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    Vera Pedro L

    2003-08-01

    Full Text Available Abstract Background Previous work suggested that macrophage migration inhibitory factor (MIF may be involved in bladder inflammation. Therefore, the location of MIF was determined immunohistochemically in the bladder, prostate, major pelvic ganglia, sympathetic chain, the L6-S1 dorsal root ganglia (DRG and the lumbosacral spinal cord of the rat. Results In the pelvic organs, MIF immunostaining was prominent in the epithelia. MIF was widely present in neurons in the MPG and the sympathetic chain. Some of those neurons also co-localized tyrosine hydroxylase (TH. In the DRGs, some of the neurons that stained for MIF also stained for Substance P. In the lumbosacral spinal cord, MIF immunostaining was observed in the white mater, the dorsal horn, the intermediolateral region and in the area around the central canal. Many cells were intensely stained for MIF and glial fibrillary acidic protein (GFAP suggesting they were glial cells. However, some cells in the lumbosacral dorsal horn were MIF positive, GFAP negative cells suggestive of neurons. Conclusions Therefore, MIF, a pro-inflammatory cytokine, is localized to pelvic organs and also in neurons of the peripheral and central nervous tissues that innervate those organs. Changes in MIF's expression at the end organ and at peripheral and central nervous system sites suggest that MIF is involved in pelvic viscera inflammation and may act at several levels to promote inflammatory changes.

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

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    Marco Aurelio M Freire

    2008-05-01

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

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

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    Doolen Suzanne

    2012-07-01

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

  19. Spatial and temporal activation of spinal glial cells: role of gliopathy in central neuropathic pain following spinal cord injury in rats.

    Science.gov (United States)

    Gwak, Young S; Kang, Jonghoon; Unabia, Geda C; Hulsebosch, Claire E

    2012-04-01

    In the spinal cord, neuron and glial cells actively interact and contribute to neurofunction. Surprisingly, both cell types have similar receptors, transporters and ion channels and also produce similar neurotransmitters and cytokines. The neuroanatomical and neurochemical similarities work synergistically to maintain physiological homeostasis in the normal spinal cord. However, in trauma or disease states, spinal glia become activated, dorsal horn neurons become hyperexcitable contributing to sensitized neuronal-glial circuits. The maladaptive spinal circuits directly affect synaptic excitability, including activation of intracellular downstream cascades that result in enhanced evoked and spontaneous activity in dorsal horn neurons with the result that abnormal pain syndromes develop. Recent literature reported that spinal cord injury produces glial activation in the dorsal horn; however, the majority of glial activation studies after SCI have focused on transient and/or acute time points, from a few hours to 1 month, and peri-lesion sites, a few millimeters rostral and caudal to the lesion site. In addition, thoracic spinal cord injury produces activation of astrocytes and microglia that contributes to dorsal horn neuronal hyperexcitability and central neuropathic pain in above-level, at-level and below-level segments remote from the lesion in the spinal cord. The cellular and molecular events of glial activation are not simple events, rather they are the consequence of a combination of several neurochemical and neurophysiological changes following SCI. The ionic imbalances, neuroinflammation and alterations of cell cycle proteins after SCI are predominant components for neuroanatomical and neurochemical changes that result in glial activation. More importantly, SCI induced release of glutamate, proinflammatory cytokines, ATP, reactive oxygen species (ROS) and neurotrophic factors trigger activation of postsynaptic neuron and glial cells via their own receptors

  20. Terminations of reticulospinal fibers originating from the gigantocellular reticular formation in the mouse spinal cord.

    Science.gov (United States)

    Liang, Huazheng; Watson, Charles; Paxinos, George

    2016-04-01

    The present study investigated the projections of the gigantocellular reticular nucleus (Gi) and its neighbors--the dorsal paragigantocellular reticular nucleus (DPGi), the alpha/ventral part of the gigantocellular reticular nucleus (GiA/V), and the lateral paragigantocellular reticular nucleus (LPGi)--to the mouse spinal cord by injecting the anterograde tracer biotinylated dextran amine (BDA) into the Gi, DPGi, GiA/GiV, and LPGi. The Gi projected to the entire spinal cord bilaterally with an ipsilateral predominance. Its fibers traveled in both the ventral and lateral funiculi with a greater presence in the ventral funiculus. As the fibers descended in the spinal cord, their density in the lateral funiculus increased. The terminals were present mainly in laminae 7-10 with a dorsolateral expansion caudally. In the lumbar and sacral cord, a considerable number of terminals were also present in laminae 5 and 6. Contralateral fibers shared a similar pattern to their ipsilateral counterparts and some fibers were seen to cross the midline. Fibers arising from the DPGi were similarly distributed in the spinal cord except that there was no dorsolateral expansion in the lumbar and sacral segments and there were fewer fiber terminals. Fibers arising from GiA/V predominantly traveled in the ventral and lateral funiculi ipsilaterally. Ipsilaterally, the density of fibers in the ventral funiculus decreased along the rostrocaudal axis, whereas the density of fibers in the lateral funiculus increased. They terminate mainly in the medial ventral horn and lamina 10 with a smaller number of fibers in the dorsal horn. Fibers arising from the LPGi traveled in both the ventral and lateral funiculi and the density of these fibers in the ventral and lateral funiculi decreased dramatically in the lumbar and sacral segments. Their terminals were present in the ventral horn with a large portion of them terminating in the motor neuron columns. The present study is the first demonstration

  1. 坐骨神经结扎对大鼠背根神经节和脊髓背角神经元磷酸化环酸腺苷反应元件结合蛋白表达的影响%Increased phosphorylation of cyclic AMP response element binding protein (CREB) in the dorsal root ganglia and superficial dorsal hornneurons following chronic constriction injury

    Institute of Scientific and Technical Information of China (English)

    姚永兴; 祝继洪; 宋学军; 张励才; 曾因明

    2005-01-01

    Objective To investigate whether chronic constriction injury (CCI) of the sciatic nerve of rats could produce alterations in the phosphorylation of cyclic AMP response element binding(CREB) protein in dorsal root ganglia (DRG) and superficial dorsal horn neurons of the spinal cord. Methods Chronic constriction injury (CCI) of the sciatic nerve was employed as a model of neuropathic pain. Thirty-two Sprague-Dawley rats were randomly divided into Naive, Sham, CCI 2w(received CCI for 2 weeks) and CCI 4w(received CCI for 4 weeks)groups. Hind paw withdrawal threshold to mechanical stimuli and withdrawal latency to thermal stimuli were used to determine the mechanical and thermal hyperalgesia. Then all the rats were deeply anesthetized and perfused intracardially with paraformaldehyde. The fixed L4-5 spinal cord and the L5 DRG ipsilateral to CCI were harvested for fixation. The pCREB-immunoreactive(pCREB-IR) cells in both DRG and superficial dorsal horn neurons were quantified for analysis using immunohistochemistry methods. Results On the 14th day after sciatic nerve injury, all the rats exhibited significant mechanical and thermal hyperalgesia. The mechanical withdrawal thresholds to yon Frey filament from CCI 2w group decreased significantly compared to both baseline values and those of Sham group( P < 0.01); Thermal withdwal latencies from CCI 2w group decreased significantly compared to both baseline values and those of Sham group( P <0.01). Some rats from Sham group also showed mechanical hyperalgesia compared to hoth baseline values and those of Naive group( P < 0.01 ). 28 days after CCI, both mechanical and thermal hypersensitivity were significantly alleviated, with no statistical significance compared to those of Sham group. On the 14th day after CCI, the number of pCREB-IR cells significantly increased in ipsilateral L5 DRGs and superficial dorsal horns( P <0.01) compared to Sham group. The number of phosphorylated CREB-IR cells in the ipsilateral DRGs

  2. Nitrergic neurons in the spinal cord of the bottlenose Dolphin (Tursiops truncatus).

    Science.gov (United States)

    Bombardi, Cristiano; Grandis, Annamaria; Gardini, Anna; Cozzi, Bruno

    2013-10-01

    Nitric oxide (NO) is a freely diffusible gaseous neurotransmitter generated by a selected population of neurons and acts as a paracrine molecule in the nervous system. NO is synthesized from l-arginine by means of the neuronal nitric oxide synthase (nNOS), an enzyme requiring nicotine adenine dinucleotide phosphate (NADPH) as cofactor. In this study, we used histochemical and immunohistochemical techniques to investigate the distribution of NADPH-diaphorase (NADPH-d) and nNOS in the spinal cord of the bottlenose dolphin (Tursiops truncatus). Cells with a fusiform-shaped somata were numerous in the laminae I and II. The intermediolateral horn showed darkly-stained cells with a multipolar morphology. Neurons with a multipolar or fusiform morphology were observed in the ventral horn. Multipolar and fusiform neurons were the most common cell types in lamina X. Nitrergic fibers were numerous especially in the dorsal and intermediolateral horns. The presence of nitrergic cells and fibers in different laminae of the spinal cord suggests that NO may be involved in spinal sensory and visceral circuitries, and potentially contribute to the regulation of the complex retia mirabilia.

  3. Branched oxytocinergic innervations from the paraventricular hypothalamic nuclei to superficial layers in the spinal cord.

    Science.gov (United States)

    Condés-Lara, Miguel; Martínez-Lorenzana, Guadalupe; Rojas-Piloni, Gerardo; Rodríguez-Jiménez, Javier

    2007-07-30

    The paraventricular nucleus (PVN) of the hypothalamus is an interesting structure with diverse functions due to its different neuronal populations, neurotransmitters, and projections to other central nervous system structures. The PVN is a primary source of oxytocin (OT) in the central nervous system. In fact, a direct PVN projection to the spinal cord has been demonstrated by retrograde and anterograde tracers, and more than the 50% of this projection is oxytocinergic. This OT descending projection is proposed to be an endogenous system that controls the nociceptive information arriving at the spinal cord. However, we have no information about the specific organization of the OT descending innervations to the different spinal cord segments. The aim of the present study was to determine whether the projecting PVN neurons arrive at cervical regions and then continue to lumbar regions. That is, we sought to establish if the OT projecting cells have a topic or a diffuse projection in order to obtain histological data to support the endogenous OT diffuse mechanism of analgesia described elsewhere. With this purpose in mind we combined the OT immunohistochemistry technique with retrograde neuronal tracers in the spinal cord. We applied Diamidino Yellow (DY) for the superficial dorsal horn cervical segments and True Blue (TB) for the lumbar segments. Data were collected from eight rats with well-placed injections. We only used the animals in which the tracer deposits were confined to superficial layers I and II of the dorsal horn. A mainly ipsilateral projection was observed, but stained neurons were also observed in the contralateral PVN. A large fraction of the stained PVN cells was doubled labeled but some were single labeled. Combining the retrograde tracer techniques and the OT detection procedure, we observed triple-labeled neurons. The present results demonstrate that PVN neurons send collaterals at least to the superficial cervical and lumbar segments of the

  4. INHIBITIVE EFFECTS OF ELECTROACUPUNCTUROACUPUNCTURE ON LTP OF SYNAPIIC IRRANSMIS-SION TO FACILITATED BY EXCITOMOTOR OF IGLURS INTRATHECAL ADMINISTRA-TION IN SPINAL DORSAL HORN OF RATS%电针抑制iGluRs激动剂鞘内给药易化的大鼠脊髓背角突触传递LTP

    Institute of Scientific and Technical Information of China (English)

    马骋; 冯克辉; 闰丽萍

    2009-01-01

    Objective:To observe the inhibitive effects of electroacupuncture(EA)on long-term potentia- tion(LTP)of C-fiber evoked potentials in the spinal dorsal horn facilitated by excitomotor of NMDA or AMPA receptors,and explore the analgesia mechanism of acupuncture in neuropathic pain.Methods: Sprague-Dawley rats were divided into 7 groups:control,NMDA(NMDA)IntratheCal administration(i. t.),AMPA([±]-AMPA HBr)i.t.,EA+NMDA i.t.,EA+AMPA i.t.,NMDA i.t.+EA,and AMPA i.t+EA.The rats were fixed on stereotaxic instrument after anesthesia.C-fiber evoked field potentials in the spinal dorsal horn(L4/L5)were recorded by extracellular recording.The test stimulus was given in single pulse with 2mA,0.5ms,100Hz,5min each once on the sciatic nerve.The lower intensity high- frequency train plus stimulus(HFS)wag given in 4 trains of 1 S duration at 10s intervals with 2mA,0. 5ms,lOOHz on same place.The NMDA or[±]-AMPA HBr(40pg)was injected with i.t.,to excite the related receptor.On GB30 and BL40,EA Wag acupunctured with 1mA,2Hz,30min.Results:In the con- trol,the variation rate of evoked potentials showed no significant differences compared with before or after HFS.After excitomotor i.t then lower intensity HFS.the LTP was induced significantly and com- pared with control(P<0.01).The exeitomotor i.t.and HFS after EA,the LTP was inhibited markedly (P<0.01).After the LTP was steady kept lhr induced by the excitomotor i.t.and HFS,the EA was operated.In NMDA i.t.+EA,LTP was inhibited markedly(P<0.01);In AMPA i.t.+EA,the LTP was step down significantly(Pdorsal hom to facilitated by excitomotor of iGluRs WaS inhibited by EA.The results indi- cate that the abnormal excitability of neuron in the spinal dorsal horn with neuropathic pain Was inhibited by EA,which might be the postsynaptic mecharism underlying EA analgesia.%目的:观察电针对离子型谷氨酸受体(iGluRs)激动剂易化脊髓背角神经元

  5. 不同传入神经损伤对大鼠神经病理性痛形成的影响及其与脊髓和背根神经节BDNF的关系%Effects of different afferent nerve injury on development of neuropathic pain and its relationship with brain-derived neurotrophic factor in spinal cord and dorsal root ganglion in rats

    Institute of Scientific and Technical Information of China (English)

    杨涛; 叶西就; 王志; 彭书凌

    2010-01-01

    Objective To investigate the effects of different afferent nerve injury on development of neuropathic pain and its relationship with brain-derived neurotrophic factor (BDNF) in spinal cord and dorsal root ganglion (DRG) in rats. Methods Twenty-four male SD rats aged 2 months weighing 200-250 g were randomly divided into 3 groups:group Ⅰ sham operation (group S); group Ⅱ sural nerve injury (group SUR) and group Ⅲ gastrocnemius-soleus nerve injury (group GS). Sural nerve and gastrocnemius-soleus nerve were transected in group SUR and GS respectively. Paw withdrawal threshold to von Frey filament stimulation was measured the day before and at day 3 and 7 after operation. The animals were killed at postoperative day 7 after the measurement of paw withdrawal threshold. The ipsllateral L5 DRG and L5 segment of the spinal cord were removed. BDNF expression in the spinal dorsal horn was determined. The percentage of BDNF positive neurons and ATF-3 positive neurons in the total DRG neurons and the percentage of BDNF positive neurons in the damaged neurons (ATF-3 positive) were calculated. Results Mechanical hyperalgesia developed after transection of gastrocnemius-soleus muscle in group GS. Mechanical pain threshold was sinificantly lower, while BDNF expression in the spinal dorsal horn and the percentage of BDNF positive neurons in total DRG neurons were significantly higher in group GS than in group S and SUR (P < 0.01). There was no significant difference in all variables between group SUR and S (P>0.05). There was no significant difference in the percentage of ATF-3 positive neurons in the total DRG neurons between group GS and SUR (P > 0.05), but the percentage of BDNF positive neurons in the damaged neurons (ATF-3 positive) was significantly higher in group GS than in group SUR (P < 0.05). Conclusion Transection of the afferent nerve innervating muscle can produce neuropathic pain through up-regulation of BDNF expression in spinal dorsal horn and DRG in

  6. Dopamine is produced in the rat spinal cord and regulates micturition reflex after spinal cord injury.

    Science.gov (United States)

    Hou, Shaoping; Carson, David M; Wu, Di; Klaw, Michelle C; Houlé, John D; Tom, Veronica J

    2016-11-01

    Dopamine (DA) neurons in the mammalian central nervous system are thought to be restricted to the brain. DA-mediated regulation of urinary activity is considered to occur through an interaction between midbrain DA neurons and the pontine micturition center. Here we show that DA is produced in the rat spinal cord and modulates the bladder reflex. We observed numerous tyrosine hydroxylase (TH)(+) neurons in the autonomic nuclei and superficial dorsal horn in L6-S3 spinal segments. These neurons are dopamine-β-hydroxylase (DBH)(-) and some contain detectable dopamine decarboxylase (DDC), suggesting their capacity to produce DA. Interestingly, following a complete thoracic spinal cord injury (SCI) to interrupt supraspinal projections, more TH(+) neurons emerged in the lumbosacral spinal cord, coincident with a sustained, low level of DA expression there and a partially recovered micturition reflex. Non-selective blockade of spinal DA receptors reduced bladder activity whereas activation of spinal D2-like receptors increased bladder activity and facilitated voiding. Additionally, depletion of lumbosacral TH(+) neurons with 6-hydroxydopamine (6-OHDA) decreased bladder non-voiding contractions and voiding efficiency. Furthermore, injecting the transsynaptic neuronal tracer pseudorabies virus (PRV) into the bladder detrusor labeled TH(+) cells in the lumbosacral cord, confirming their involvement in spinal micturition reflex circuits. These results illustrate that DA is synthesized in the rat spinal cord; plasticity of lumbosacral TH(+) neurons following SCI may contribute to DA expression and modulate the spinal bladder reflex. Thus, spinally-derived DA and receptors could be a novel therapeutic target to improve micturition recovery after SCI. Published by Elsevier Inc.

  7. Effect of changes of PKC activity on iNOS in posterior horn neurons of spinal cord in rats after formalin-induced inflammatory pain and hyperalgesia%甲醛足底致痛大鼠脊髓后角神经元内蛋白激酶C活性改变对一氧化氮合酶的影响

    Institute of Scientific and Technical Information of China (English)

    吕兴业

    2011-01-01

    目的 通过改变蛋白激酶C(protein kinase C,PKC)的活性观察其对甲醛炎性痛及痛觉过敏时大鼠脊髓后角一氧化氮合酶(nitric oxide synthase,NOS)尤其是对诱生型NOS(induciable NOS,iNOS)的影响,以探讨在该过程中PKC的作用机制.方法 将实验动物54只分为9组,每组6只,分男q为正常组、甲醛12 h组、甲醛24 h组、甲醛12 h加0.9%氯化钠溶液组、甲醛24 h加0.9%氯化钠溶液组、甲醛12 h加佛波醇脂(PMA)组、甲醛24 h加PMA组、甲醛12 h加灯盏花素乙(CH)组和甲醛24 h加CH组.先进行疼痛行为学检测,然后分别于注射甲醛后12、24 h将大鼠麻醉后取材,采用免疫组织化学方法观察脊髓后角iNOS阳性神经元数目及染色深度,以探讨PKC时NOS的影响.结果 与甲醛12 h组比较,甲醛12 h加PMA组iNOS阳性细胞数明显增加(P<0.01),神经细胞及神经纤维染色也明显加深(P<0.01);甲醛12 h加CH组iNOS阳性细胞数明显减少(P<0.01),神经细胞及神经纤维染色明显变浅(P<0.01).同时产生相应的行为痛觉过敏变化.结论 鞘内注射PKC兴奋荆PMA能显著增加L5脊髓后角神经元NOS的活性;鞘内注射PKC抑制剂CH能显著抑制L5脊髓后角神经元iNOS的活性.在甲醛炎性痛及痛觉过敏中,脊髓后角iNOS活性在一定程度上受PKC调控.%Objective To observe the effect of changes of protein kinase C (PKC) activity on nitric oxide synthase (NOS) and inducible NOS (iNOS) in posterior horn neurons of spinal cord in rats after formalin-induced inflammatory pain and hyperalgesia in order to explore the action mechanism of PKC during the process. Methods Fifty-four SD rats were randomly divided into 9 groups:control group, formalin 12h, formalin 24h, formalin 12h +NS,formalin 24 h + N, formalin 12h + PMA, formalin 24h + PMA, formalin 12h + CH and formalin 24h + CH groups. The mechanical and thermal pain threshold was measured by paw withdrawal latencies to yon Frey hair and radiant heat

  8. Influence of Pain - Relieving Plaster on Expressions of pERK and pCREB in Spinal Dorsal Horn of Rats with Bone Cancer Pain%中药止痛巴布贴对骨癌痛大鼠脊髓背角p - ERK、p-CREB的影响

    Institute of Scientific and Technical Information of China (English)

    姜涌; 王文萍

    2012-01-01

    目的:观察中药止痛巴布贴对骨癌痛大鼠痛行为及骨髓背角神经节pERK、pCREB表达的影响.方法:108只180 ~ 220g雌性Wistar大鼠随机分为3组,分别为空白对照组(Con组,n=24)、假手术组(Sham组,n=24)、骨癌痛模型组(Ca组,n=60),3组分别于手术前2天、术后每隔4日测定机械痛阈(MWT)和热痛阈(TWL).于术后7天确认造模成功后,将成功的模型鼠随机分为两组,即模型组(Ca组,n=28)和中药止痛巴布贴组(CM组,n=25).术后7天、14天和21天各组处死大鼠(n≥8),取大鼠脊髓腰椎L4-6膨大处,用免疫组化方法测定脊髓背角pERK、pCREB的变化.结果:脊髓背角神经pERK、pCREB表达:Ca组阳性神经元数目增加,术后7天、术后14、21天与Con组和Sham组比较有统计学差异(P<0.05);CM组于术后14天、术后21天与Con组和Sham组统计学差异逐渐缩小(P>0.05).结论:中药止痛巴布贴对骨癌痛有比较明显的镇痛作用,其对脊髓背角c-fos的影响,可能是通过降低脊髓背角神经节pERK、pCREB的表达而产生的,即通过ERK - CREB 信号转导通路完成的.%Objective: The influence of Pain - Relieving Plaster on expressions of pERK and pCREB in the spinal dorsal hom of rats with bone cancer pain. Method: 108 female Wistar rats(180 ~220g)were randomly divided into 3 groups, respectively : blank control group (group Con, n — 24), sham operation group (group Sham, n = 24), bone cancer pain model group (group Ca, n =60). The 3 groups were determined mechanical pain threshold (MWT) and thermal pain threshold(TWL)2 days before operation and every 4 days after operation. On the 7th day after operation, the successful model rats were randomly divided into two groups; the model group (group Ca, n =25) and Pain - Relieving Plaster group (group CM, n =18). After 7 days, 14 days and 21 days rats in each group were sacrificed( n≥8),the determination of pERK and pCREB in spinal dorsal horn of L4 - 6 was modified by

  9. Ryanodine receptors contribute to the induction of nociceptive input-evoked long-term potentiation in the rat spinal cord slice

    Directory of Open Access Journals (Sweden)

    Zhao Zhi-Qi

    2010-01-01

    Full Text Available Abstract Background Our previous study demonstrated that nitric oxide (NO contributes to long-term potentiation (LTP of C-fiber-evoked field potentials by tetanic stimulation of the sciatic nerve in the spinal cord in vivo. Ryanodine receptor (RyR is a downstream target for NO. The present study further explored the role of RyR in synaptic plasticity of the spinal pain pathway. Results By means of field potential recordings in the adult male rat in vivo, we showed that RyR antagonist reduced LTP of C-fiber-evoked responses in the spinal dorsal horn by tetanic stimulation of the sciatic nerve. Using spinal cord slice preparations and field potential recordings from superficial dorsal horn, high frequency stimulation of Lissauer's tract (LT stably induced LTP of field excitatory postsynaptic potentials (fEPSPs. Perfusion of RyR antagonists blocked the induction of LT stimulation-evoked spinal LTP, while Ins(1,4,5P3 receptor (IP3R antagonist had no significant effect on LTP induction. Moreover, activation of RyRs by caffeine without high frequency stimulation induced a long-term potentiation in the presence of bicuculline methiodide and strychnine. Further, in patch-clamp recordings from superficial dorsal horn neurons, activation of RyRs resulted in a large increase in the frequency of miniature EPSCs (mEPSCs. Immunohistochemical study showed that RyRs were expressed in the dorsal root ganglion (DRG neurons. Likewise, calcium imaging in small DRG neurons illustrated that activation of RyRs elevated [Ca2+]i in small DRG neurons. Conclusions These data indicate that activation of presynaptic RyRs play a crucial role in the induction of LTP in the spinal pain pathway, probably through enhancement of transmitter release.

  10. Effect of morphine on synaptic long-term potentiation in spinal dorsal horn evoked by electric stimulation of sciatic nerve in rats%吗啡对电刺激坐骨神经诱发大鼠脊髓背角突触长时程增强的影响

    Institute of Scientific and Technical Information of China (English)

    吴江; 黄德樱; 程洁; 上官守琴; 胡祁生

    2009-01-01

    Objective To evaluate the effect of morphine on synaptic long-term potentiation (LTP) in the spinal dorsal horn evoked by electric stimulation of sciatic nerve in rats. Methods Twenty-seven healthy male SD rats aged 60-90 d weighing 180-200 g were randomly divided into 4 groups: group Ⅰ control (group C, n=7), group Ⅱ morphine (group M, n=7), group Ⅲ naloxone (group N, n=6), and group Ⅳ morphine + naloxone (group MN, n=7). The animals were anesthetized with intraperitoneal 10% urethane 1 g/kg, intubated and then mechanically ventilated. The bipolar insulated stainless steel recording electrode (impedance 0.5-1 MΩ, diameter 0.1 mm) was inserted into the left side of the spinal dorsal horn at T13-L1 to stimulate the left side of the sciatic nerve. Single square pulses (15 V, 0.5 ms, 1/60 Hz for 30 min) was applied to evoke spinal field potentials. Normal saline 10 μl, morphine 10 μl (15 μg/μl), naloxone 10 μl (2.5 μg/μl), and the mixture 10 μl of naloxone 5 μl (2.5 μg/μl) and morphine 5 μl (15 μg/μl) was gradually instilled over 2 rain in the 4 groups respectively. Five minutes later, high-frequency and intensity tetanic stimulation (30-40 V, 0.5 ms, 100 Hz, given in 4 trains of 1-s duration at 10-s intervals) was used to induce LTP. Then single square stimuli (15 V, 5 ms, 1/60 Hz) were applied to the sciatic nerve for 210 min. The amplitude and latency period of the field potential were recorded 30 min before tetanic stimulation, and 0-30, 35-60, 65-120 and 125-210 min after titanic stimulation. Results Compared with group C, the amplitude of the field potential was significantly decreased and the latency period prolonged in group M and MN, but there was no significant difference in the above indices between group N and C. Compared with group M, the amplitude of the field potential was significantly increased and the latency period shortened in group MN. Compared with those 30 min before the tetanic stimulation, the amplitude of the field

  11. Time course of immediate early gene protein expression in the spinal cord following conditioning stimulation of the sciatic nerve in rats.

    Science.gov (United States)

    Bojovic, Ognjen; Panja, Debabrata; Bittins, Margarethe; Bramham, Clive R; Tjølsen, Arne

    2015-01-01

    Long-term potentiation induced by conditioning electrical stimulation of afferent fibers is a widely studied form of synaptic plasticity in the brain and the spinal cord. In the spinal cord dorsal horn, long-term potentiation is induced by a series of high-frequency trains applied to primary afferent fibers. Conditioning stimulation (CS) of sciatic nerve primary afferent fibers also induces expression of immediate early gene proteins in the lumbar spinal cord. However, the time course of immediate early gene expression and the rostral-caudal distribution of expression in the spinal cord have not been systematically studied. Here, we examined the effects of sciatic nerve conditioning stimulation (10 stimulus trains, 0.5 ms stimuli, 7.2 mA, 100 Hz, train duration 2 s, 8 s intervals between trains) on cellular expression of immediate early genes, Arc, c-Fos and Zif268, in anesthetized rats. Immunohistochemical analysis was performed on sagittal sections obtained from Th13- L5 segments of the spinal cord at 1, 2, 3, 6 and 12 h post-CS. Strikingly, all immediate early genes exhibited a monophasic increase in expression with peak increases detected in dorsal horn neurons at 2 hours post-CS. Regional analysis showed peak increases at the location between the L3 and L4 spinal segments. Both Arc, c-Fos and Zif268 remained significantly elevated at 2 hours, followed by a sharp decrease in immediate early gene expression between 2 and 3 hours post-CS. Colocalization analysis performed at 2 hours post-CS showed that all c-Fos and Zif268 neurons were positive for Arc, while 30% and 43% of Arc positive neurons were positive for c-Fos and Zif268, respectively. The present study identifies the spinal cord level and time course of immediate early gene (IEGP) expression of relevance for analysis of IEGPs function in neuronal plasticity and nociception.

  12. 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.

  13. FOS EXPRESSION IN LUMBARSACRAL SPINAL CORD AND MEDULLA OBLONGATA INDUCED BY CHRONIC COLONIC INFLAMMATION IN RATS

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective To investigate Fos expression in rat lumbarsacral spinal cord and medulla oblongata induced by chronic colonic inflammation. Methods Thirty-three male Sprague-Dawley rats were randomly divided into two groups: experimental group: colonic inflammation was induced in seventeen rats by intraluminal administration of trinitrobenzenesulfonic acid (TNBS); control group: saline was administered intraluminally in sixteen rats; After 3, 7, 14 and 28 days of administration, lumbarsacral spinal cord and medulla oblongata were removed and processed for Fos immunohistochemistry. Results Fos-immunoreactive (Fos-IR) neurons induced by TNBS administration were primarily distributed in deep laminae (laminae Ⅲ-Ⅳ,Ⅴ-Ⅵ) in the spinal dorsal horn and in medullary visceral zone (MVZ) in the medulla oblongata. The number of Fos-IR cells in the spinal cord and MVZ in rats after 7 and 14 days of TNBS administration were significantly higher than that in the control rats (P<0.05). After 28 days of TNBS instillation, the number of Fos-IR neurons in MVZ decreased and became comparable to the control group. However, the number of Fos cells in the spinal cord in some rats were still significantly increased compared with the control rats (P<0.05). Conclusion Fos-IR neurons after colonic inflammation recovery may play an important role in the development of visceral hypersensitivity. Medulla oblongata was a less important structure than the spinal cord in inducing visceral hypersensitivity after chronic colonic inflammation.

  14. Inflammation unmasks gabapentin's effect on Aδ-fiber evoked excitatory postsynaptic currents in substantia gelatinosa neurons of rat spinal cord

    Institute of Scientific and Technical Information of China (English)

    刘智良; 徐如祥; 杨鲲

    2003-01-01

    ObjectiveTo study the analgesic mechanism of gabapentin, an anticonvulsant, during antinociceptive clinical treatment. MethodsWhole-cell voltage-clamp recordings were taken from adult rat spinal cord slices to investigate the effect of gabapentin on primary afferent Aδ-fiber evokedexcitatory postsynaptic currents (EPSCs) to substantia gelatinosa (SG) neurons in normal and inflamed (established by plantar injection of carrageenan) rats. Results Gabapentin (5-20 μmol/L for 5 min) depressed dorsal root Aδ fiber evoked polysynaptic, but not monosynaptic EPSCs to SG experiencing inflammation by about 25ptic or monosynaptic EPSCs in normal rats. Gabapentin failed to block a glutamate receptor subtype, N-methyl-D-aspartate (NMDA), -induced slow excitatory currents on SG neurons.ConclusionsInflammation, at least in part, unmasks the gabapentin depression on nociception transmission in the dorsal horn, and this depression is not due to the blockade of postsynaptic NMDA receptor.

  15. Effect of low-frequency transcutaneous electrical nerve stimulation on the action potential of spinal cord posterior horn cells in rats after peripheral nerve injury%低频电疗对白鼠周围神经损伤后脊髓后角神经细胞活动电位的影响

    Institute of Scientific and Technical Information of China (English)

    崔松彪; 赵和荣; 吴光; 朴虎男; 许梅花

    2006-01-01

    度刺激所引发的脊髓后角神经细胞的膜电位明显高于注射前[每10 s(174.5±0.41),(235.4±1.41)次,P<0.01].结论:低频电刺激能有效抑制被无害刺激所引发的脊髓后角神经细胞的活动电位,且静脉注射纳洛酮(8 mg/kg)可使之逆转到治疗前的水平,说明低频电疗可能是刺激中枢神经系统使其分泌内源鸦片物质,作用于脊髓后角细胞使其活性降低,从而达到缓解疼痛的目的.%BACKGROUND: Up to now, few studies related to the mechanism of low-frequency transcutaneous electrical nerve stimulation (TENS) in relieving pain, and the effect of low-frequency TENS on the activity potential of dorsal horn cells in rats after peripheral nerve injury. OBJECTIVE: To observe the effects of low-frequency TENS on the activity potential of dorsal horn cells induced by mechanical allodynia and thermal allodynia by using animal models of peripheral nerve injury, and observe the efficacy after interfering of naloxone. DESIGN: A randomized control animal study. SETTING: Department of Neurology, Affiliated Hospital of Medical College, Yanbian University. MATERIALS: The experiment was carried out in the central laboratory of Medical College, Yanbian University between February and October 2004. Eighty male Sprague-Dawley rats were used, and 60 random selected ones were operated to separate sciatic nerve, two branch tibial nerves and sural nerves of sciatic nerve were amputated after ligation, and peroneal nerve was left as the experimental group; the other 20 rats were placed at the origin after sciatic nerve was separated, and then the skin was sutured as the control group. METHODS: ① Pain detection (Behavioral test): At 1 week postoperatively, the rats were given mechanical allodynia and thermal allodynia once every 5 seconds for 10 times, and then the frequency of foot withdrawal was detected (0%-40% for mild pain, 40%-70% for moderate pain; 70% and above for severe pain). ② The spontaneous

  16. 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 terminatio...

  17. Riluzole improves outcome following ischemia-reperfusion injury to the spinal cord by preventing delayed paraplegia.

    Science.gov (United States)

    Wu, Y; Satkunendrarajah, K; Fehlings, M G

    2014-04-18

    The spinal cord is vulnerable to ischemic injury due to trauma, vascular malformations and correction of thoracic aortic lesions. Riluzole, a sodium channel blocker and anti-glutamate drug has been shown to be neuroprotective in a model of ischemic spinal cord injury, although the effects in clinically relevant ischemia/reperfusion models are unknown. Here, we examine the effect of riluzole following ischemia-reperfusion injury to the spinal cord. Female rats underwent high thoracic aortic balloon occlusion to produce an ischemia/reperfusion injury. Tolerance to ischemia was evaluated by varying the duration of occlusion. Riluzole (8mg/kg) was injected intraperitoneally 4h after injury. Locomotor function (Basso, Beattie and Bresnahan (BBB) scale) was assessed at 4h, 1day, and 5days post-ischemia. Spinal cords were extracted and evaluated for neuronal loss using immunohistology (choline acetyltransferase (ChAT) and neuronal nuclei (NeuN)), inflammation (CD11b), astrogliosis (glial fibrillary acidic protein - GFAP) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). Ischemic injury lasting between 5.5 and 6.75min resulted in delayed paraplegia, whereas longer ischemia induced immediate paraplegia. When riluzole was administered to rats that underwent 6min of occlusion, delayed paraplegia was prevented. The BBB score of riluzole-treated rats was 11.14±4.85 compared with 1.86±1.07 in control animals. Riluzole also reduced neuronal loss, infiltration of microglia/macrophages and astrogliosis in the ventral horn and intermediate zone of the gray matter. In addition, riluzole reduced apoptosis of neurons in the dorsal horn of the gray matter. Riluzole has a neuroprotective effect in a rat model of spinal cord injury/reperfusion when administered up to 4h post-injury, a clinically relevant therapeutic time window.

  18. The Ram's Horn.

    Science.gov (United States)

    Rassias, John A., Ed.; And Others

    1983-01-01

    The summer-fall and winter-spring numbers of the journal, "The Ram's Horn," contain these articles: "The Text as Dramatic Departure"; "The Dartmouth Language Outreach Approach to Spanish for Police Action"; "The Dartmouth Intensive Language Model (DILM) in Florida: John Rassias with High School Teachers"; "The Flexibility of Using Drama Techniques…

  19. 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

  20. Nanowired Delivery of Growth Hormone Attenuates Pathophysiology of Spinal Cord Injury and Enhances Insulin-Like Growth Factor-1 Concentration in the Plasma and the Spinal Cord.

    Science.gov (United States)

    Muresanu, Dafin F; Sharma, Aruna; Lafuente, José V; Patnaik, Ranjana; Tian, Z Ryan; Nyberg, Fred; Sharma, Hari S

    2015-10-01

    Previous studies from our laboratory showed that topical application of growth hormone (GH) induced neuroprotection 5 h after spinal cord injury (SCI) in a rat model. Since nanodelivery of drugs exerts superior neuroprotective effects, a possibility exists that nanodelivery of GH will induce long-term neuroprotection after a focal SCI. SCI induces GH deficiency that is coupled with insulin-like growth factor-1 (IGF-1) reduction in the plasma. Thus, an exogenous supplement of GH in SCI may enhance the IGF-1 levels in the cord and induce neuroprotection. In the present investigation, we delivered TiO2-nanowired growth hormone (NWGH) after a longitudinal incision of the right dorsal horn at the T10-11 segments in anesthetized rats and compared the results with normal GH therapy on IGF-1 and GH contents in the plasma and in the cord in relation to blood-spinal cord barrier (BSCB) disruption, edema formation, and neuronal injuries. Our results showed a progressive decline in IGF-1 and GH contents in the plasma and the T9 and T12 segments of the cord 12 and 24 h after SCI. Marked increase in the BSCB breakdown, as revealed by extravasation of Evans blue and radioiodine, was seen at these time points after SCI in association with edema and neuronal injuries. Administration of NWGH markedly enhanced the IGF-1 levels and GH contents in plasma and cord after SCI, whereas normal GH was unable to enhance IGF-1 or GH levels 12 or 24 h after SCI. Interestingly, NWGH was also able to reduce BSCB disruption, edema formation, and neuronal injuries after trauma. On the other hand, normal GH was ineffective on these parameters at all time points examined. Taken together, our results are the first to demonstrate that NWGH is quite effective in enhancing IGF-1 and GH levels in the cord and plasma that may be crucial in reducing pathophysiology of SCI.

  1. Effect of nitric oxide with different doses on Bcl-2/Bax in spinal dorsal horn in rats induced by formalin%不同剂量的一氧化氮对福尔马林炎性痛大鼠脊髓背角Bcl-2/Bax表达的影响

    Institute of Scientific and Technical Information of China (English)

    未小明; 李宽; 祁文秀

    2011-01-01

    Objective: To investigate the effects of multiple application of different doses of nitric oxide (NO) on Bcl-2/ Bax in spinal dorsal horn induced by formalin. Methods: A succession of 4 d intrathecal injection of NO precursor L-arginine (L-Arg)10 μg/d (low L-Arg group) or 250 μg/d (high L-Arg group) or NOS inhibitor Nω-nitro-L-arginine methylester (L-NAME) 2700 μg/d (L-NAME group) in rats, and normal saline (NS group) was applied as a control, and administration once a day. Then rats were subcutaneously injected formalin (2%, 100 μL) into the right hindpaw, four hours later after formalin injection, Bcl-2 or Bax protein expression were detected with immunocytochemistry and Western Blot. Results: The immunocytochemistry showed the distributions of Bcl-2 and Bax were in both sides of the dorsal horn,especially in superficial laminae, and the expressions of bcl-2 and bax in the ipsilateral side of formalin injection were significantly increased than that in contralateral side of formalin injection in all four groups; the ratio of Bcl-2/Bax with Western-Blot was increased in low L-Arg group compared with normal saline group and was all decreased in high L-Arg group or L-NAME group compared with normal saline group. bcl-2 and bax are two major genes in the regulation of apoptosis, bcl-2 inhibits apoptosis and bax promotes apoptosis. Conclusion: Therefore, in inflammatory pain model, low doses of NO can promote the antiapoptotic gene expression, while high doses of NO and insufficient of NO both can promote pro-apoptotic gene expression, which affect the incidence of inflammatory pain.%目的:探讨多次应用不同剂量的一氧化氮(NO)对福尔马林炎性痛中脊髓背角神经元Bcl-2、Bax表达的影响.方法:连续4 d给大鼠各进行鞘内注射不同剂量的一氧化氮前体左旋精氨酸(L-arginine,L-Arg)10μg/d(低L-Arg组)、250 μg/d(高L-Arg组)或一氧化氮合酶(nitric oxide synthase,NOS)抑制剂Nω-硝基-L

  2. Spinal autofluorescent flavoprotein imaging in a rat model of nerve injury-induced pain and the effect of spinal cord stimulation.

    Directory of Open Access Journals (Sweden)

    Joost L M Jongen

    Full Text Available Nerve injury may cause neuropathic pain, which involves hyperexcitability of spinal dorsal horn neurons. The mechanisms of action of spinal cord stimulation (SCS, an established treatment for intractable neuropathic pain, are only partially understood. We used Autofluorescent Flavoprotein Imaging (AFI to study changes in spinal dorsal horn metabolic activity. In the Seltzer model of nerve-injury induced pain, hypersensitivity was confirmed using the von Frey and hotplate test. 14 Days after nerve-injury, rats were anesthetized, a bipolar electrode was placed around the affected sciatic nerve and the spinal cord was exposed by a laminectomy at T13. AFI recordings were obtained in neuropathic rats and a control group of naïve rats following 10 seconds of electrical stimulation of the sciatic nerve at C-fiber strength, or following non-noxious palpation. Neuropathic rats were then treated with 30 minutes of SCS or sham stimulation and AFI recordings were obtained for up to 60 minutes after cessation of SCS/sham. Although AFI responses to noxious electrical stimulation were similar in neuropathic and naïve rats, only neuropathic rats demonstrated an AFI-response to palpation. Secondly, an immediate, short-lasting, but strong reduction in AFI intensity and area of excitation occurred following SCS, but not following sham stimulation. Our data confirm that AFI can be used to directly visualize changes in spinal metabolic activity following nerve injury and they imply that SCS acts through rapid modulation of nociceptive processing at the spinal level.

  3. Alterations in the neural circuits from peripheral afferents to the spinal cord: possible implications for diabetic polyneuropathy in streptozotocin-induced type 1 diabetic rats

    Directory of Open Access Journals (Sweden)

    Zhen-Zhen eKou

    2014-01-01

    Full Text Available Diabetic polyneuropathy (DPN presents as a wide variety of sensorimotor symptoms and affects approximately 50% of diabetic patients. Changes in the neural circuits may occur in the early stages in diabetes and are implicated in the development of DPN. Therefore, we aimed to detect changes in the expression of isolectin B4 (IB4, the marker for nonpeptidergic unmyelinated fibers and their cell bodies and calcitonin gene-related peptide (CGRP, the marker for peptidergic fibers and their cell bodies in the dorsal root ganglion (DRG and spinal cord of streptozotocin (STZ-induced type 1 diabetic rats showing alterations in sensory and motor function. We also used cholera toxin B subunit (CTB to show the morphological changes of the myelinated fibers and motor neurons. STZ-induced diabetic rats exhibited hyperglycemia, decreased body weight gain, mechanical allodynia and impaired locomotor activity. In the DRG and spinal dorsal horn, IB4-labeled structures decreased, but both CGRP immunostaining and CTB labeling increased from day 14 to day 28 in diabetic rats. In spinal ventral horn, CTB labeling decreased in motor neurons in diabetic rats. Treatment with intrathecal injection of insulin at the early stages of DPN could alleviate mechanical allodynia and impaired locomotor activity in diabetic rats. The results suggest that the alterations of the neural circuits between spinal nerve and spinal cord via the DRG and ventral root might be involved in DPN.

  4. Spinal autofluorescent flavoprotein imaging in a rat model of nerve injury-induced pain and the effect of spinal cord stimulation.

    Science.gov (United States)

    Jongen, Joost L M; Smits, Helwin; Pederzani, Tiziana; Bechakra, Malik; Hossaini, Mehdi; Koekkoek, Sebastiaan K; Huygen, Frank J P M; De Zeeuw, Chris I; Holstege, Jan C; Joosten, Elbert A J

    2014-01-01

    Nerve injury may cause neuropathic pain, which involves hyperexcitability of spinal dorsal horn neurons. The mechanisms of action of spinal cord stimulation (SCS), an established treatment for intractable neuropathic pain, are only partially understood. We used Autofluorescent Flavoprotein Imaging (AFI) to study changes in spinal dorsal horn metabolic activity. In the Seltzer model of nerve-injury induced pain, hypersensitivity was confirmed using the von Frey and hotplate test. 14 Days after nerve-injury, rats were anesthetized, a bipolar electrode was placed around the affected sciatic nerve and the spinal cord was exposed by a laminectomy at T13. AFI recordings were obtained in neuropathic rats and a control group of naïve rats following 10 seconds of electrical stimulation of the sciatic nerve at C-fiber strength, or following non-noxious palpation. Neuropathic rats were then treated with 30 minutes of SCS or sham stimulation and AFI recordings were obtained for up to 60 minutes after cessation of SCS/sham. Although AFI responses to noxious electrical stimulation were similar in neuropathic and naïve rats, only neuropathic rats demonstrated an AFI-response to palpation. Secondly, an immediate, short-lasting, but strong reduction in AFI intensity and area of excitation occurred following SCS, but not following sham stimulation. Our data confirm that AFI can be used to directly visualize changes in spinal metabolic activity following nerve injury and they imply that SCS acts through rapid modulation of nociceptive processing at the spinal level.

  5. Fluorescence histochemical study of the localisation and distribution of beta-adrenergic receptor sites in the spinal cord and cerebellum of the chicken.

    Science.gov (United States)

    Bondok, A A; Botros, K G; el-Mohandes, E A

    1988-10-01

    The distribution of beta-adrenergic receptor sites has been studied in chicken spinal cord and cerebellum using a fluorescent analogue of propranolol, 9-amino-acridin-propranolol (9-AAP). In the cervical and lumbar regions of the spinal cord, beta-adrenoceptor sites were concentrated on cell bodies of alpha-motor neurons of the dorsolateral and ventrolateral nuclear groups of the ventral horn. In the thoracic region, they were present on cell bodies of the preganglionic sympathetic nucleus (dorsal commissural nucleus). In the dorsal horn, the receptor sites were present mainly on cell bodies of columna dorsalis magnocellularis. Sparse distribution of fluorescence was present in other regions of the gray matter. In the cerebellum, a dense distribution of beta-adrenergic receptor sites was observed on Purkinje cell bodies and their apical dendrites. Sparse distribution of receptor sites was present on fine ramifications of Purkinje cell dendrites in the molecular layer. Receptor sites were absent in the granule cell layer and the white matter. These observations indicate that alpha-motor neurons, preganglionic sympathetic neurons, neurons of columna dorsalis magnocellularis, and Purkinje cells are adrenoceptive, while granule cells are non-adrenoceptive.

  6. 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.

  7. Up-regulation of -opioid receptors in the spinal cord of morphine-tolerant rats

    Indian Academy of Sciences (India)

    Subrata Basu Ray; Himanshu Gupta; Yogendra Kumar Gupta

    2004-03-01

    Though morphine remains the most powerful drug for treating pain, its effectiveness is limited by the development of tolerance and dependence. The mechanism underlying development of tolerance to morphine is still poorly understood. One of the factors could be an alteration in the number of m-receptors within specific parts of the nervous system. However, reports on changes in the -opioid receptor density in the spinal cord after chronic morphine administration are conflicting. Most of the studies have used subcutaneously implanted morphine pellets to produce tolerance. However, it does not simulate clinical conditions, where it is more common to administer morphine at intervals, either by injections or orally. In the present study, rats were made tolerant to morphine by injecting increasing doses of morphine (10–50 mg/kg, subcutaneously) for five days. In vitro tissue autoradiography for localization of -receptor in the spinal cord was done using [3H]-DAMGO. As compared to the spinal cord of control rats, the spinal cord of tolerant rats showed an 18.8% increase or up-regulation in the density of -receptors in the superficial layers of the dorsal horn. This up-regulation of -receptors after morphine tolerance suggests that a fraction of the receptors have been rendered desensitized, which in turn could lead to tolerance.

  8. Calcium Imaging of Living Astrocytes in the Mouse Spinal Cord following Sensory Stimulation

    Directory of Open Access Journals (Sweden)

    Giovanni Cirillo

    2012-01-01

    Full Text Available Astrocytic Ca2+ dynamics have been extensively studied in ex vivo models; however, the recent development of two-photon microscopy and astrocyte-specific labeling has allowed the study of Ca2+ signaling in living central nervous system. Ca2+ waves in astrocytes have been described in cultured cells and slice preparations, but evidence for astrocytic activation during sensory activity is lacking. There are currently few methods to image living spinal cord: breathing and heart-beating artifacts have impeded the widespread application of this technique. We here imaged the living spinal cord by two-photon microscopy in C57BL6/J mice. Through pressurized injection, we specifically loaded spinal astrocytes using the red fluorescent dye sulforhodamine 101 (SR101 and imaged astrocytic Ca2+ levels with Oregon-Green BAPTA-1 (OGB. Then, we studied astrocytic Ca2+ levels at rest and after right electrical hind paw stimulation. Sensory stimulation significantly increased astrocytic Ca2+ levels within the superficial dorsal horn of the spinal cord compared to rest. In conclusion, in vivo morphofunctional imaging of living astrocytes in spinal cord revealed that astrocytes actively participate to sensory stimulation.

  9. 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.

  10. Antiproton Focus Horn

    CERN Multimedia

    1974-01-01

    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 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.

  11. 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.

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

    DEFF Research Database (Denmark)

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

    2001-01-01

    and having either inhibitory or excitatory ZEN terminals. The ZEN neurons seem to form a vast network of terminals located primarily in the gray matter, but also contacting dendrites radiating into the white matter. Important functions of this rather massive system of ZEN terminals can not be deduced from......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......SeAMG-labeled ZEN neurons appeared in Rexed's laminae V, VII and X while laminae I and II were void. A few scattered ZEN somata were observed in the remaining laminae. The labeled neurons differed in shape and size, and the relatively high level of labeled somata around the injection site suggests that many ZEN...

  13. 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.

  14. Decoding intravesical pressure from local field potentials in rat lumbosacral spinal cord

    Science.gov (United States)

    Im, Changkyun; Park, Hae Yong; Koh, Chin Su; Ryu, Sang Baek; Seo, In Seok; Kim, Yong Jung; Kim, Kyung Hwan; Shin, Hyung-Cheul

    2016-10-01

    Chronic monitoring of intravesical pressure is required to detect the onset of intravesical hypertension and the progression of a more severe condition. Recent reports demonstrate the bladder state can be monitored from the spiking activity of the dorsal root ganglia or lumbosacral spinal cord. However, one of the most serious challenges for these methods is the difficulty of sustained spike signal acquisition due to the high-electrode-location-sensitivity of spikes or neuro-degeneration. Alternatively, it has been demonstrated that local field potential recordings are less affected by encapsulation reactions or electrode location changes. Here, we hypothesized that local field potential (LFP) from the lumbosacral dorsal horn may provide information concerning the intravesical pressure. LFP and spike activities were simultaneously recorded from the lumbosacral spinal cord of anesthetized rats during bladder filling. The results show that the LFP activities carry significant information about intravesical pressure along with spiking activities. Importantly, the intravesical pressure is decoded from the power in high-frequency bands (83.9-256 Hz) with a substantial performance similar to that of the spike train decoding. These findings demonstrate that high-frequency LFP activity can be an alternative intravesical pressure monitoring signal, which could lead to a proper closed loop system for urinary control.

  15. Puerarin Alleviates Neuropathic Pain by Inhibiting Neuroinflammation in Spinal Cord

    Directory of Open Access Journals (Sweden)

    Ming Liu

    2014-01-01

    Full Text Available Neuropathic pain responds poorly to drug treatments, and partial relief is achieved in only about half of the patients. Puerarin, the main constituent of Puerariae Lobatae Radix, has been used extensively in China to treat hypertension and tumor. The current study examined the effects of puerarin on neuropathic pain using two most commonly used animal models: chronic constriction injury (CCI and diabetic neuropathy. We found that consecutive intrathecal administration of puerarin (4–100 nM for 7 days inhibited the mechanical and thermal nociceptive response induced by CCI and diabetes without interfering with the normal pain response. Meanwhile, in both models puerarin inhibited the activation of microglia and astroglia in the spinal dorsal horn. Puerarin also reduced the upregulated levels of nuclear factor-κB (NF-κB and other proinflammatory cytokines, such as IL-6, IL-1β, and TNF-α, in the spinal cord. In summary, puerarin alleviated CCI- and diabetes-induced neuropathic pain, and its effectiveness might be due to the inhibition of neuroinflammation in the spinal cord. The anti-inflammation effect of puerarin might be related to the suppression of spinal NF-κB activation and/or cytokines upregulation. We conclude that puerarin has a significant effect on alleviating neuropathic pain and thus may serve as a therapeutic approach for neuropathic pain.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nandi, K.N.; Beal, J.A.; Knight, D.S. (Louisiana State Univ. Medical Center, Shreveport (USA))

    1990-02-01

    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. Serotonin, Dopamine and Noradrenaline Adjust Actions of Myelinated Afferents via Modulation of Presynaptic Inhibition in the Mouse Spinal Cord

    Science.gov (United States)

    García-Ramírez, David L.; Calvo, Jorge R.; Hochman, Shawn; Quevedo, Jorge N.

    2014-01-01

    Gain control of primary afferent neurotransmission at their intraspinal terminals occurs by several mechanisms including primary afferent depolarization (PAD). PAD produces presynaptic inhibition via a reduction in transmitter release. While it is known that descending monoaminergic pathways complexly regulate sensory processing, the extent these actions include modulation of afferent-evoked PAD remains uncertain. We investigated the effects of serotonin (5HT), dopamine (DA) and noradrenaline (NA) on afferent transmission and PAD. Responses were evoked by stimulation of myelinated hindlimb cutaneous and muscle afferents in the isolated neonatal mouse spinal cord. Monosynaptic responses were examined in the deep dorsal horn either as population excitatory synaptic responses (recorded as extracellular field potentials; EFPs) or intracellular excitatory postsynaptic currents (EPSCs). The magnitude of PAD generated intraspinally was estimated from electrotonically back-propagating dorsal root potentials (DRPs) recorded on lumbar dorsal roots. 5HT depressed the DRP by 76%. Monosynaptic actions were similarly depressed by 5HT (EFPs 54%; EPSCs 75%) but with a slower time course. This suggests that depression of monosynaptic EFPs and DRPs occurs by independent mechanisms. DA and NA had similar depressant actions on DRPs but weaker effects on EFPs. IC50 values for DRP depression were 0.6, 0.8 and 1.0 µM for 5HT, DA and NA, respectively. Depression of DRPs by monoamines was nearly-identical in both muscle and cutaneous afferent-evoked responses, supporting a global modulation of the multimodal afferents stimulated. 5HT, DA and NA produced no change in the compound antidromic potentials evoked by intraspinal microstimulation indicating that depression of the DRP is unrelated to direct changes in the excitability of intraspinal afferent fibers, but due to metabotropic receptor activation. In summary, both myelinated afferent-evoked DRPs and monosynaptic transmission in the

  18. Serotonin, dopamine and noradrenaline adjust actions of myelinated afferents via modulation of presynaptic inhibition in the mouse spinal cord.

    Directory of Open Access Journals (Sweden)

    David L García-Ramírez

    Full Text Available Gain control of primary afferent neurotransmission at their intraspinal terminals occurs by several mechanisms including primary afferent depolarization (PAD. PAD produces presynaptic inhibition via a reduction in transmitter release. While it is known that descending monoaminergic pathways complexly regulate sensory processing, the extent these actions include modulation of afferent-evoked PAD remains uncertain. We investigated the effects of serotonin (5HT, dopamine (DA and noradrenaline (NA on afferent transmission and PAD. Responses were evoked by stimulation of myelinated hindlimb cutaneous and muscle afferents in the isolated neonatal mouse spinal cord. Monosynaptic responses were examined in the deep dorsal horn either as population excitatory synaptic responses (recorded as extracellular field potentials; EFPs or intracellular excitatory postsynaptic currents (EPSCs. The magnitude of PAD generated intraspinally was estimated from electrotonically back-propagating dorsal root potentials (DRPs recorded on lumbar dorsal roots. 5HT depressed the DRP by 76%. Monosynaptic actions were similarly depressed by 5HT (EFPs 54%; EPSCs 75% but with a slower time course. This suggests that depression of monosynaptic EFPs and DRPs occurs by independent mechanisms. DA and NA had similar depressant actions on DRPs but weaker effects on EFPs. IC50 values for DRP depression were 0.6, 0.8 and 1.0 µM for 5HT, DA and NA, respectively. Depression of DRPs by monoamines was nearly-identical in both muscle and cutaneous afferent-evoked responses, supporting a global modulation of the multimodal afferents stimulated. 5HT, DA and NA produced no change in the compound antidromic potentials evoked by intraspinal microstimulation indicating that depression of the DRP is unrelated to direct changes in the excitability of intraspinal afferent fibers, but due to metabotropic receptor activation. In summary, both myelinated afferent-evoked DRPs and monosynaptic

  19. Role of spinal cord alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors in complete Freund's adjuvant-induced inflammatory pain

    Directory of Open Access Journals (Sweden)

    Shih Ming-Hung

    2008-12-01

    Full Text Available Abstract Spinal cord α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs mediate acute spinal processing of nociceptive and non-nociceptive information, but whether and how their activation contributes to the central sensitization that underlies persistent inflammatory pain are still unclear. Here, we examined the role of spinal AMPARs in the development and maintenance of complete Freund's adjuvant (CFA-induced persistent inflammatory pain. Intrathecal application of two selective non-competitive AMPAR antagonists, CFM-2 (25 and 50 μg and GYKI 52466 (50 μg, significantly attenuated mechanical and thermal hypersensitivities on the ipsilateral hind paw at 2 and 24 h post-CFA injection. Neither CFM-2 nor GYKI 52466 affected the contralateral basal responses to thermal and mechanical stimuli. Locomotor activity was not altered in any of the drug-treated animals. CFA-induced inflammation did not change total expression or distribution of AMPAR subunits GluR1 and GluR2 in dorsal horn but did alter their subcellular distribution. The amount of GluR2 was markedly increased in the crude cytosolic fraction and decreased in the crude membrane fraction from the ipsilateral L4–5 dorsal horn at 24 h (but not at 2 h post-CFA injection. Conversely, the level of GluR1 was significantly decreased in the crude cytosolic fraction and increased in the crude membrane fraction from the ipsilateral L4–5 dorsal horn at 24 h (but not at 2 h post-CFA injection. These findings suggest that spinal AMPARs might participate in the central spinal mechanism of persistent inflammatory pain.

  20. Endomorphin-2 Inhibition of Substance P Signaling within Lamina I of the Spinal Cord Is Impaired in Diabetic Neuropathic Pain Rats

    Science.gov (United States)

    Wan, Fa-Ping; Bai, Yang; Kou, Zhen-Zhen; Zhang, Ting; Li, Hui; Wang, Ya-Yun; Li, Yun-Qing

    2017-01-01

    Opiate analgesia in the spinal cord is impaired in diabetic neuropathic pain (DNP), but until now the reason is unknown. We hypothesized that it resulted from a decreased inhibition of substance P (SP) signaling within the dorsal horn of the spinal cord. To investigate this possibility, we evaluated the effects of endomorphin-2 (EM2), an endogenous ligand of the μ-opioid receptor (MOR), on SP release within lamina I of the spinal dorsal horn (SDH) in rats with DNP. We established the DNP rat model and compared the analgesic efficacy of EM2 between inflammation pain and DNP rat models. Behavioral results suggested that the analgesic efficacy of EM2 was compromised in the condition of painful diabetic neuropathy. Then, we measured presynaptic SP release induced by different stimulating modalities via neurokinin-1 receptor (NK1R) internalization. Although there was no significant change in basal and evoked SP release between control and DNP rats, EM2 failed to inhibit SP release by noxious mechanical and thermal stimuli in DNP but not in control and inflammation pain model. We also observed that EM2 decreased the number of FOS-positive neurons within lamina I of the SDH but did not change the amount of FOS/NK1R double-labeled neurons. Finally, we identified a remarkable decrease in MORs within the primary afferent fibers and dorsal root ganglion (DRG) neurons by Western blot (WB) and immunohistochemistry (IHC). Taken together, these data suggest that reduced presynaptic MOR expression might account for the loss of the inhibitory effect of EM2 on SP signaling, which might be one of the neurobiological foundations for decreased opioid efficacy in the treatment of DNP. PMID:28119567

  1. Conservation, Innovation, and Bias: Embryonic Segment Boundaries Position Posterior, but Not Anterior, Head Horns in Adult Beetles.

    Science.gov (United States)

    Busey, Hannah A; Zattara, Eduardo E; Moczek, Armin P

    2016-07-01

    The integration of form and function of novel traits is a fundamental process during the developmental evolution of complex organisms, yet how novel traits and trait functions integrate into preexisting contexts remains poorly understood. Here, we explore the mechanisms by which the adult insect head has been able to integrate novel traits and features during its ontogeny, focusing on the cephalic horns of Onthophagus beetles. Specifically, using a microablation approach we investigate how different regions of the dorsal head of adult horned beetles relate to their larval and embryonic counterparts and test whether deeply conserved regional boundaries that establish the embryonic head might also facilitate or bias the positioning of cephalic horns along the dorsal adult head. We find that paired posterior horns-the most widespread horn type within the genus-are positioned along a border homologous to the embryonic clypeolabral (CL)-ocular boundary, and that this placement constitutes the ancestral form of horn positioning. In contrast, we observed that the phylogenetically much rarer anterior horns are positioned by larval head regions contained firmly within the CL segment and away from any major preexisting larval head landmarks or boundaries. Lastly, we describe the unexpected finding that ablations at medial head regions can result in ectopic outgrowths bearing terminal structures resembling the more anterior clypeal ridge. We discuss our results in the light of the developmental genetic mechanisms of head formation in holometabolous insects and the role of co-option in innovation and bias in developmental evolution.

  2. 大麻素受体2激动剂JWH-015对骨癌痛大鼠脊髓背角磷酸化环磷酸腺苷反应元件结合蛋白的影响%The effect of intraperitoneal injection cannabinoid 2 receptor agonist JWH-015 on the expression of phosphorylated cyclic AMP response element binding protein in spinal dorsal horn in a rat model of bone cancer pain

    Institute of Scientific and Technical Information of China (English)

    孙蓓; 张羽; 冷鑫; 顾小萍; 马正良

    2014-01-01

    目的 探讨腹腔注射大麻素受体(cannabinoid receptor,CB)2激动剂对骨癌痛大鼠脊髓背角磷酸化环磷酸腺苷反应元件结合蛋白(phosphorylated cyclic AMP response element binding protein,pCREB)表达的影响. 方法 运用随机数字表法将63只雌性SD大鼠分为3组:肿瘤给药组(J组,15只)、肿瘤对照组(D组,24只)和假手术对照组(S组,24只).J组、D组的大鼠左侧胫骨上端骨髓腔被注入5μlWalker256大鼠乳腺癌细胞制备骨癌痛模型;S组则注入等量的生理盐水.在造模后第10天,J组腹腔注射JWH-015(100 μg/500μl),D组、S组注射等量JWH-015溶剂二甲基亚髓砜(dimethylsulfoxide,DMSO).每组大鼠于造模前1d,造模后4、7、10 d,腹腔注射后2、6、24、48、72 h,检测手术侧机械刺激缩足阈值(paw withdrawal mechanicalthreshold,PWMT)和行走痛行为学评分.D组和S组大鼠于造模后4、7d,J组、D组和S组大鼠于造模后10 d及腹腔注射后6、24、72 h,取脊髓腰膨大进行免疫印迹分析. 结果 与S组比较,J组和D组大鼠造模后7 d PWMT开始降低(P<0.05),造模后10 d行走痛行为学评分增加(P<0.05),脊髓背角pCREB表达水平于7、10 d上调(P<0.05).与D组比较,腹腔注射JWH-015后24 h,J组PWMT(8.7±1.6)g显著上升(P<0.05),行走痛行为学评分(1.0±0.6)分和pCREB的表达(0.56±0.10)明显下降(P<0.05). 结论 腹腔注射JWH-015可能通过下调脊髓背角pCREB的表达改善骨癌痛大鼠的痛行为.%Objective To investigate the change of phosphorylated cyclic AMP response element binding protein (pCREB) in spinal dorsal horn in a rat model of bone cancer pain,after intraperitoneal injection JWH-015.Methods Sixty-three female SD rats were randomly divided into 3 group:medication administration of JWH-015 group (group J,n=15),medication administration of dimethylsulfoxide (DMSO) group (group D,n=15) and sham group (group S,n=21).Group J,D:5 μl Walker256 breast cancer cells of rat were implanted

  3. Up-regulation and time course of protein kinase C immunoreactivity during persistent inflammation of the rat spinal cord

    Institute of Scientific and Technical Information of China (English)

    Liping Yang; Qingjun Li

    2008-01-01

    BACKGROUND: It has been reported that activation and/or translocation of protein kinase C (PKC) is related to hyperalgesia, and changes in PKC expression in the dorsal horn of spinal cord take place during inflammatory pain.OBJECTIVE: To observe PKC changes in the dorsal horn of spinal cord using immunohistochemistry and to measure the time-course during persistent pain produced by chemical stimulation with a right hind-paw injection of formalin. DESIGN: Randomized controlled animal experiment.SETTING: Institute of Basic Medical Science, Hebei Medical UniversityMATERIALS: The present experiment was performed at the Department of Pathophysiology, Institute of Basic Medical Science, Hebei Medical University between September 2000 and June 2002. Forty-two Sprague-Dawley rats, weighing 260-280 g, irrespective of gender, were provided by the Center of Animal Experimentation at Hebei Medical University. PKC antibody was provided by Sigma, USA. Immunohistochemistry kits were purchased from Zhongshan Biotechnology Company, Beijing. HPIAS-1000 definition multicolor system was provided by Qianping Wuxiang Project Company of Tongji Medical University. Animal use during experimentation was consistent with the standards of Animal Ethics Committee.METHODS: Sprague-Dawley rats were divided randomly into control (n = 6) and experimental groups (n = 36). Experimental rats were given an intracutaneous injection of 5% formalin into the planta surface of the right hind-paw. Animals with inflammatory pain were anesthetized and sacrificed to obtain the L5 spinal region at 1, 3, 12 hours, 1, 3, and 7 days after formalin treatment, with 6 rats in each time group. The spinal cords at the L5 region were collected from the control group following sodium chloride injections into the planta surface of the right hind-paw, identical to the experimental group. MAIN OUTCOME MEASURES: Pain reaction of experimental rats after formalin treatment. PKC-positive neurons, and distribution of PKC

  4. 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.

  5. Activation of ERK/CREB pathway in spinal cord contributes to chronic constrictive injury-induced neuropathic pain in rats

    Institute of Scientific and Technical Information of China (English)

    Xue-song SONG; Jun-li CAO; Yan-bing XU; Jian-hua HE; Li-cai ZHANG; Yin-ming ZENG

    2005-01-01

    Aim: To investigate whether activation and translocation of extracellular signalregulated kinase (ERK) is involved in the induction and maintenance of neuropathic pa in, and effects of activation and translocation of ERK on expression of pCREB and Fos in the chronic neuropathic pain.Methods: Lumbar intrathecal catheters were chronically implanted in male Sprague-Dawley rats.The left sciatic nerve was loosely ligated proximal to the sciatica's trifurcation at approximately 1.0 mm intervals with 4-0 silk sutures.The mitogen-activated protein kinase kinase (MEK) inhibitor U0126 or phosphorothioate-modified antisense oligonucleotides (ODN) were intrathecally administered every 12 h, 1 d pre-chronic constriction injury (CCI) and 3 d post-CCI.Thermal and mechanical nociceptive thresholds were assessed with the paw withdrawal latency (PWL) to radiant heat and yon Frey filaments.The expression of pERK, pCREB, and Fos were assessed by both Western blotting and immunohistochemical analysis.Results: Intrathecal injection of U0126 or ERK antisense ODN significantly attenuated CCI-induced mechanical allodynia and thermal hyperalgesia.CCI significantly increased the expression of p-ERK-IR neurons in the ipsilateral spinal dorsal horn to injury, not in the contralateral spinal dorsal horn.The time courses of pERK expression showed that the levels of both cytosol and nuclear pERK, but not total ERK, were increased at all points after CCI and reached a peak level on postoperative d 5.CCI also significantly increased the expression of pCREB and Fos.Phospho-CREB-positive neurons were distributed in all laminae of the bilateral spinal cord and Fos was expressed in laminae Ⅰ and Ⅱ of the ipsilateral spinal dorsal horn.Intrathecal injection of U0126 or ERK antisense ODN markedly suppressed the increase of CCI-induced pERK, pCREB and c-Fos expression in the spinal cord.Conclusion:The activation of ERK pathways contributes to neuropathic pain in CCI rats, and the function of pERK may

  6. Modulus of elasticity and dry-matter content of bovine claw horn affected by the changes of chronic laminitis.

    Science.gov (United States)

    Hinterhofer, Christine; Apprich, Veronika; Ferguson, James C; Stanek, Christian

    2007-11-01

    The mechanical properties of horn samples from 22 hind claws with chronic laminitis were determined in adult Austrian Fleckvieh cows. The resistance to deformation was quantified as the modulus of elasticity (E). Tension tests revealed mean E values of 520MPa for the dorsal wall, 243MPa for the abaxial wall, 339MPa for the axial wall and 97MPa for the sole. E tended to be lower in laminitic horn than in sound horn in all segments tested, with the difference being largest in the abaxial wall. The mean dry-matter content (DMC) of the laminitic claws was 75.8% in the dorsal wall, 75.86% in the abaxial wall, 71.15% in the axial wall and 69.28% in the sole. These values are generally comparable to those for sound claws except in the axial wall. Further, E and DMC were only correlated in the axial wall. Chronic laminitis leads to a low resistance of claw horn to mechanical insults in the dorsal wall, abaxial wall and sole, and to the loss of a correlation between the E and DMC in these segments. The reason for these alterations is therefore not increased ingress of moisture, but must be due to changes in the microstructure, biochemical components and/or horn formation by the diseased dermis.

  7. Intrathecal co-administration of ketamine and morphine preventing activation of astrocytes and decreasing releases of IL-1β and IL-6 from spinal cord in rats of morphine tolerance

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective: To investigate the effects of intrathecal administration of ketamine, a non-competitive N-methy-D-aspartate receptor antagonist, combined with morphine on the activation of astrocytes and releases of IL-1β and IL-6 from spinal cord in the rats of morphine tolerance. Methods: Twenty-seven Sprague-Dawley male rats were randomly divided into sham-operated, morphine tolerance, and morphine plus ketamine group. The subarachnoid catheterization of all the rats was prepared by the method of Jianping Yang.Morphine 20 μg in 10 μl was administrated intrathecally to induce spinal morphine tolerance once daily for 5 consecutive days. Morphine and ketamine 250 μg in 10 μl total volume was given in morphine plus ketamine group. Three groups all received intrathecal morphine 5 μg in 10 μl for morphine challenge test at 24 h after last administration of the morphine. After morphine challenge test, lumbar spinal tissues were taken for measurement of glial fibrillary acidic protein (GFAP) of astrocyte in lumbar spinal horn cord by immunohistochemistry and IL-1βand IL-6 of spinal cord by ELISA. Results: The decrease of %MPE induced by chronic intrathecal morphine was inhibited by ketamine and hyperalgesia and allodynia induced by morphine-withdrawl were alleviated. The average areas, the average absorbency (-A), the integral absorbency (A) of GFAP immuno-reactive cells in the dorsal horn, and IL-1β and IL-6 of spinal cord were significantly larger in morphine tolerance group than in morphine plus ketamine group. Conclusion: Co-administration of ketamine and morphine enhance antinociceptive effect of morphine and prevent the development of morphine tolerance. Ketamine might attenuate the activation of astrocytes and inhibit the release of IL-1β and IL-6 from spinal cord in repeated intrathecal morphine rats.

  8. Sensory and spinal inhibitory dorsal midline crossing is independent of Robo3

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    John Daniel Comer

    2015-07-01

    Full Text Available Commissural neurons project across the midline at all levels of the central nervous system, providing bilateral communication critical for the coordination of motor activity and sensory perception. Midline crossing at the spinal ventral midline has been extensively studied and has revealed that multiple developmental lineages contribute to this commissural neuron population. Ventral midline crossing occurs in a manner dependent on Robo3 regulation of Robo/Slit signaling and the ventral commissure is absent in the spinal cord and hindbrain of Robo3 mutants. Midline crossing in the spinal cord is not limited to the ventral midline, however. While prior anatomical studies provide evidence that commissural axons also cross the midline dorsally, little is known of the genetic and molecular properties of dorsally-crossing neurons or of the mechanisms that regulate dorsal midline crossing. In this study, we describe a commissural neuron population that crosses the spinal dorsal midline during the last quarter of embryogenesis in discrete fiber bundles present throughout the rostrocaudal extent of the spinal cord. Using immunohistochemistry, neurotracing, and mouse genetics, we show that this commissural neuron population includes spinal inhibitory neurons and sensory nociceptors. While the floor plate and roof plate are dispensable for dorsal midline crossing, we show that this population depends on Robo/Slit signaling yet crosses the dorsal midline in a Robo3-independent manner. The dorsally-crossing commissural neuron population we describe suggests a substrate circuitry for pain processing in the dorsal spinal cord.

  9. Distribution of 28 kDa calbindin-immunopositive neurons in the cat spinal cord

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    Natalia eMerkulyeva

    2016-01-01

    Full Text Available The distribution of vitamin D-dependent calcium-binding protein (28 kDa calbindin was investigated in cat lumbar and sacral spinal cord segments (L1-S3. We observed specific multi-dimensional distributions over the spinal segments for small immunopositive cells in Rexed laminae II-III and medium-to-large cells of varying morphology in lamina I and laminae V-VIII. The small neurons in laminae II-III were clustered into the columns along the dorsal horn curvature. The medium-to-large cells were grouped into four assemblages that were located in (1 the most lateral region of lamina VII at the L1-L4 level, (2 the laminae IV-V boundary at the L5-L7 level, (3 the lamina VII dorsal border at the L5-L7 level; (4 the lamina VIII at the L5-S3 level. The data obtained suggest that the morphological and physiological heterogeneity of calbindin immunolabeling cells formed morpho-functional clusters over the gray matter. A significant portion of the lumbosacral enlargement had immunopositive neurons within all Rexed laminae, suggesting an important functional role within and among the spinal networks that control hindlimb movements.

  10. Electromigration Issues in High Current Horn

    CERN Document Server

    Zhang, Wu; Hseuh, Brigitte; Sandberg, Jon; Simos, Nikolaos; Tuozzolo, Joseph; Weng, Wu-Tsung

    2005-01-01

    The secondary particle focusing horn for the AGS neutrino experiment proposal is a high current and high current density device. The peak current of horn is 300 kA. At the smallest area of horn, the current density is near 8 kA/mm2. At very high current density, a few kA/mm2, the electromigration phenomena will occur. Momentum transfer between electrons and metal atoms at high current density causes electromigration. The reliability and lifetime of focusing horn can be severely reduced by electromigration. In this paper, we discuss issues such as device reliability model, incubation time of electromigration, and lifetime of horn.

  11. Hyperbaric oxygenation alleviates chronic constriction injury (CCI)-induced neuropathic pain and inhibits GABAergic neuron apoptosis in the spinal cord.

    Science.gov (United States)

    Fu, Huiqun; Li, Fenghua; Thomas, Sebastian; Yang, Zhongjin

    2017-09-15

    Dysfunction of GABAergic inhibitory controls contributes to the development of neuropathic pain. We examined our hypotheses that (1) chronic constriction injury (CCI)-induced neuropathic pain is associated with increased spinal GABAergic neuron apoptosis, and (2) hyperbaric oxygen therapy (HBO) alleviates CCI-induced neuropathic pain by inhibiting GABAergic neuron apoptosis. Male rats were randomized into 3 groups: CCI, CCI+HBO and the control group (SHAM). Mechanical allodynia was tested daily following CCI procedure. HBO rats were treated at 2.4 atmospheres absolute (ATA) for 60min once per day. The rats were euthanized and the spinal cord harvested on day 8 and 14 post-CCI. Detection of GABAergic cells and apoptosis was performed. The percentages of double positive stained cells (NeuN/GABA), cleaved caspase-3 or Cytochrome C in total GABAergic cells or in total NeuN positive cells were calculated. HBO significantly alleviated mechanical allodynia. CCI-induced neuropathic pain was associated with significantly increased spinal apoptotic GABA-positive neurons. HBO considerably decreased these spinal apoptotic cells. Cytochrome-C-positive neurons and cleaved caspase-3-positive neurons were also significantly higher in CCI rats. HBO significantly decreased these positive cells. Caspase-3 mRNA was also significantly higher in CCI rats. HBO reduced mRNA expression of caspase-3. CCI-induced neuropathic pain was associated with increased apoptotic GABAergic neurons induced by activation of key proteins of mitochondrial apoptotic pathways in the dorsal horn of the spinal cord. HBO alleviated CCI-induced neuropathic pain and reduced GABAergic neuron apoptosis. The beneficial effect of HBO may be via its inhibitory role in CCI-induced GABAergic neuron apoptosis by suppressing mitochondrial apoptotic pathways in the spinal cord. Increased apoptotic GABAergic neurons induced by activation of key proteins of mitochondrial apoptotic pathways in the dorsal horn of the spinal

  12. Interneuronal systems of the cervical spinal cord assessed with BOLD imaging at 1.5 T

    Energy Technology Data Exchange (ETDEWEB)

    Stracke, C.P.; Schoth, F.; Moeller-Hartmann, W.; Krings, T. [University Hospital of the University of Technology, Departments of Neuroradiology and Diagnostic Radiology, Aachen (Germany); Pettersson, L.G. [University of Goeteborg, Department of Physiology, Goeteborg (Sweden)

    2005-02-01

    The purpose of this study was to investigate if functional activity with spinal cord somatosensory stimulation can be visualized using BOLD fMRI. We investigated nine healthy volunteers using a somatosensory stimulus generator. The stimuli were applied in three different runs at the first, third, and fifth finger tip of the right hand, respectively, corresponding to dermatomes c6, c7, and c8. The stimuli gave an increase of BOLD signal (activation) in three different locations of the spinal cord and brain stem. First, activations could be seen in the spinal segment corresponding to the stimulated dermatome in seven out of nine volunteers for c6 stimulation, two out of eight for c7, and three out of eight for c8. These activations were located close to the posterior margin of the spinal cord, presumably reflecting synaptic transmission to dorsal horn interneurons. Second, activation in the medulla oblongata was evident in four subjects, most likely corresponding to the location of the nucleus cuneatus. The third location of activation, which was the strongest and most reliable observed was inside the spinal cord in the c3 and c4 segments. Activation at these spinal levels was almost invariably observed independently of the dermatome stimulated (9/9 for c6, 8/8 for c7, and 7/8 for c8 stimulation). These activations may pertain to an interneuronal system at this spinal level. The results are discussed in relation to neurophysiological studies on cervical spinal interneuronal pathways in animals and humans. (orig.)

  13. Bortezomib Treatment Produces Nocifensive Behavior and Changes in the Expression of TRPV1, CGRP, and Substance P in the Rat DRG, Spinal Cord, and Sciatic Nerve

    Directory of Open Access Journals (Sweden)

    M. Quartu

    2014-01-01

    Full Text Available To investigate neurochemical changes associated with bortezomib-induced painful peripheral neuropathy (PN, we examined the effects of a single-dose intravenous administration of bortezomib and a well-established “chronic” schedule in a rat model of bortezomib-induced PN. The TRPV1 channel and sensory neuropeptides CGRP and substance P (SP were studied in L4-L5 dorsal root ganglia (DRGs, spinal cord, and sciatic nerve. Behavioral measures, performed at the end of the chronic bortezomib treatment, confirmed a reduction of mechanical nociceptive threshold, whereas no difference occurred in thermal withdrawal latency. Western blot analysis showed a relative increase of TRPV1 in DRG and spinal cord after both acute and chronic bortezomib administration. Reverse transcriptase-polymerase chain reaction revealed a decrease of TRPV1 and CGRP mRNA relative levels after chronic treatment. Immunohistochemistry showed that in the DRGs, TRPV1-, CGRP-, and SP-immunoreactive neurons were mostly small- and medium-sized and the proportion of TRPV1- and CGRP-labeled neurons increased after treatment. A bortezomib-induced increase in density of TRPV1- and CGRP-immunoreactive innervation in the dorsal horn was also observed. Our findings show that bortezomib-treatment selectively affects subsets of DRG neurons likely involved in the processing of nociceptive stimuli and that neurochemical changes may contribute to development and persistence of pain in bortezomib-induced PN.

  14. Characterization of a cerebral palsy-like model in rats: Analysis of gait pattern and of brain and spinal cord motor areas.

    Science.gov (United States)

    Dos Santos, Adriana Souza; de Almeida, Wellington; Popik, Bruno; Sbardelotto, Bruno Marques; Torrejais, Márcia Miranda; de Souza, Marcelo Alves; Centenaro, Lígia Aline

    2017-08-01

    In an attempt to propose an animal model that reproduces in rats the phenotype of cerebral palsy, this study evaluated the effects of maternal exposure to bacterial endotoxin associated with perinatal asphyxia and sensorimotor restriction on gait pattern, brain and spinal cord morphology. Two experimental groups were used: Control Group (CTG) - offspring of rats injected with saline during pregnancy and Cerebral Palsy Group (CPG) - offspring of rats injected with lipopolysaccharide during pregnancy, submitted to perinatal asphyxia and sensorimotor restriction for 30days. At 29days of age, the CPG exhibited coordination between limbs, weight-supported dorsal steps or weight-supported plantar steps with paw rotation. At 45days of age, CPG exhibited plantar stepping with the paw rotated in the balance phase. An increase in the number of glial cells in the primary somatosensory cortex and dorsal striatum were observed in the CPG, but the corpus callosum thickness and cross-sectional area of lateral ventricle were similar between studied groups. No changes were found in the number of motoneurons, glial cells and soma area of the motoneurons in the ventral horn of spinal cord. The combination of insults in the pre, peri and postnatal periods produced changes in hindlimbs gait pattern of animals similar to those observed in diplegic patients, but motor impairments were attenuated over time. Besides, the greater number of glial cells observed seems to be related to the formation of a glial scar in important sensorimotor brain areas. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

  15. Blockade of neuronal dopamine D2 receptor attenuates morphine tolerance in mice spinal cord

    Science.gov (United States)

    Dai, Wen-Ling; Xiong, Feng; Yan, Bing; Cao, Zheng-Yu; Liu, Wen-Tao; Liu, Ji-Hua; Yu, Bo-Yang

    2016-01-01

    Tolerance induced by morphine remains a major unresolved problem and significantly limits its clinical use. Recent evidences have indicated that dopamine D2 receptor (D2DR) is likely to be involved in morphine-induced antinociceptive tolerance. However, its exact effect and molecular mechanism remain unknown. In this study we examined the effect of D2DR on morphine antinociceptive tolerance in mice spinal cord. Chronic morphine treatment significantly increased levels of D2DR in mice spinal dorsal horn. And the immunoreactivity of D2DR was newly expressed in neurons rather than astrocytes or microglia both in vivo and in vitro. Blockade of D2DR with its antagonist (sulpiride and L-741,626, i.t.) attenuated morphine antinociceptive tolerance without affecting basal pain perception. Sulpiride (i.t.) also down-regulated the expression of phosphorylation of NR1, PKC, MAPKs and suppressed the activation of astrocytes and microglia induced by chronic morphine administration. Particularly, D2DR was found to interact with μ opioid receptor (MOR) in neurons, and chronic morphine treatment enhanced the MOR/D2DR interactions. Sulpiride (i.t.) could disrupt the MOR/D2DR interactions and attenuate morphine tolerance, indicating that neuronal D2DR in the spinal cord may be involved in morphine tolerance possibly by interacting with MOR. These results may present new opportunities for the treatment and management of morphine-induced antinociceptive tolerance which often observed in clinic. PMID:28004735

  16. Photochemically induced cystic lesion in the rat spinal cord. I. Behavioral and morphological analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, T.; Prado, R.; Watson, B.D.; Gonzalez-Carvajal, M.; Holets, V.R. (Univ. of Miami, FL (USA))

    1990-08-01

    The present study describes the production of a spinal cord lesion which is initiated by vascular occlusion resulting from the interaction between the photosensitizing dye erythrosin B and an argon laser beam. The lesion has characteristics similar to those of the central cavity thought to lead to the production of post-traumatic syringomyelia (PTS) in humans. The present study examines the behavioral and morphological characteristics of this injury over a 28-day period. Histological analysis revealed a cavity extending from the dorsal horns to lamina VIII, with some lateral and ventral pathways being spared. The cavity volume reached a maximum 7 days after lesion induction. Behavioral changes were assessed using six different tests of motor and reflex function (motor function, climbing, waterbath, inclined plane, withdrawal to pain, and withdrawal to extension). Lesioned animals exhibited flaccid paralysis for 3-5 days, which resolved afterward. The photochemically induced cavity should provide a reproducible model for examining the effects of cystic spinal cord injury on locomotor and reflex function.

  17. Direct Effect of Remifentanil and Glycine Contained in Ultiva® on Nociceptive Transmission in the Spinal Cord: In Vivo and Slice Patch Clamp Analyses.

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    Makoto Sumie

    Full Text Available Ultiva® is commonly administered intravenously for analgesia during general anaesthesia and its main constituent remifentanil is an ultra-short-acting μ-opioid receptor agonist. Ultiva® is not approved for epidural or intrathecal use in clinical practice. Previous studies have reported that Ultiva® provokes opioid-induced hyperalgesia by interacting with spinal dorsal horn neurons. Ultiva® contains glycine, an inhibitory neurotransmitter but also an N-methyl-D-aspartate receptor co-activator. The presence of glycine in the formulation of Ultiva® potentially complicates its effects. We examined how Ultiva® directly affects nociceptive transmission in the spinal cord.We made patch-clamp recordings from substantia gelatinosa (SG neurons in the adult rat spinal dorsal horn in vivo and in spinal cord slices. We perfused Ultiva® onto the SG neurons and analysed its effects on the membrane potentials and synaptic responses activated by noxious mechanical stimuli.Bath application of Ultiva® hyperpolarized membrane potentials under current-clamp conditions and produced an outward current under voltage-clamp conditions. A barrage of excitatory postsynaptic currents (EPSCs evoked by the stimuli was suppressed by Ultiva®. Miniature EPSCs (mEPSCs were depressed in frequency but not amplitude. Ultiva®-induced outward currents and suppression of mEPSCs were not inhibited by the μ-opioid receptor antagonist naloxone, but were inhibited by the glycine receptor antagonist strychnine. The Ultiva®-induced currents demonstrated a specific equilibrium potential similar to glycine.We found that intrathecal administration of Ultiva® to SG neurons hyperpolarized membrane potentials and depressed presynaptic glutamate release predominantly through the activation of glycine receptors. No Ultiva®-induced excitatory effects were observed in SG neurons. Our results suggest different analgesic mechanisms of Ultiva® between intrathecal and intravenous

  18. Direct Effect of Remifentanil and Glycine Contained in Ultiva® on Nociceptive Transmission in the Spinal Cord: In Vivo and Slice Patch Clamp Analyses

    Science.gov (United States)

    Sumie, Makoto; Shiokawa, Hiroaki; Yamaura, Ken; Karashima, Yuji; Hoka, Sumio; Yoshimura, Megumu

    2016-01-01

    Background Ultiva® is commonly administered intravenously for analgesia during general anaesthesia and its main constituent remifentanil is an ultra-short-acting μ-opioid receptor agonist. Ultiva® is not approved for epidural or intrathecal use in clinical practice. Previous studies have reported that Ultiva® provokes opioid-induced hyperalgesia by interacting with spinal dorsal horn neurons. Ultiva® contains glycine, an inhibitory neurotransmitter but also an N-methyl-D-aspartate receptor co-activator. The presence of glycine in the formulation of Ultiva® potentially complicates its effects. We examined how Ultiva® directly affects nociceptive transmission in the spinal cord. Methods We made patch-clamp recordings from substantia gelatinosa (SG) neurons in the adult rat spinal dorsal horn in vivo and in spinal cord slices. We perfused Ultiva® onto the SG neurons and analysed its effects on the membrane potentials and synaptic responses activated by noxious mechanical stimuli. Results Bath application of Ultiva® hyperpolarized membrane potentials under current-clamp conditions and produced an outward current under voltage-clamp conditions. A barrage of excitatory postsynaptic currents (EPSCs) evoked by the stimuli was suppressed by Ultiva®. Miniature EPSCs (mEPSCs) were depressed in frequency but not amplitude. Ultiva®-induced outward currents and suppression of mEPSCs were not inhibited by the μ-opioid receptor antagonist naloxone, but were inhibited by the glycine receptor antagonist strychnine. The Ultiva®-induced currents demonstrated a specific equilibrium potential similar to glycine. Conclusions We found that intrathecal administration of Ultiva® to SG neurons hyperpolarized membrane potentials and depressed presynaptic glutamate release predominantly through the activation of glycine receptors. No Ultiva®-induced excitatory effects were observed in SG neurons. Our results suggest different analgesic mechanisms of Ultiva® between intrathecal

  19. Substance P immunoreactivity in the lumbar spinal cord of the turtle Trachemys dorbigni following peripheral nerve injury

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    W.A. Partata

    2003-04-01

    Full Text Available Immunoreactive substance P was investigated in turtle lumbar spinal cord after sciatic nerve transection. In control animals immunoreactive fibers were densest in synaptic field Ia, where the longest axons invaded synaptic field III. Positive neuronal bodies were identified in the lateral column of the dorsal horn and substance P immunoreactive varicosities were observed in the ventral horn, in close relationship with presumed motoneurons. Other varicosities appeared in the lateral and anterior funiculi. After axotomy, substance P immunoreactive fibers were reduced slightly on the side of the lesion, which was located in long fibers that invaded synaptic field III and in the varicosities of the lateral and anterior funiculus. The changes were observed at 7 days after axonal injury and persisted at 15, 30, 60 and 90 days after the lesion. These findings show that turtles should be considered as a model to study the role of substance P in peripheral axonal injury, since the distribution and temporal changes of substance P were similar to those found in mammals.

  20. Differential Histopathological and Behavioral Outcomes Eight Weeks after Rat Spinal Cord Injury by Contusion, Dislocation, and Distraction Mechanisms

    Science.gov (United States)

    Chen, Kinon; Liu, Jie; Assinck, Peggy; Bhatnagar, Tim; Streijger, Femke; Zhu, Qingan; Dvorak, Marcel F.; Kwon, Brian K.; Tetzlaff, Wolfram

    2016-01-01

    Abstract The objective of this study was to compare the long-term histological and behavioral outcomes after spinal cord injury (SCI) induced by one of three distinct biomechanical mechanisms: dislocation, contusion, and distraction. Thirty male Sprague-Dawley rats were randomized to incur a traumatic cervical SCI by one of these three clinically relevant mechanisms. The injured cervical spines were surgically stabilized, and motor function was assessed for the following 8 weeks. The spinal cords were then harvested for histologic analysis. Quantification of white matter sparing using Luxol fast blue staining revealed that dislocation injury caused the greatest overall loss of white matter, both laterally and along the rostrocaudal axis of the injured cord. Distraction caused enlarged extracellular spaces and structural alteration in the white matter but spared the most myelinated axons overall. Contusion caused the most severe loss of myelinated axons in the dorsal white matter. Immunohistochemistry for the neuronal marker NeuN combined with Fluoro Nissl revealed that the dislocation mechanism resulted in the greatest neuronal cell losses in both the ventral and dorsal horns. After the distraction injury mechanism, animals displayed no recovery of grip strength over time, in contrast to the animals subjected to contusion or dislocation injuries. After the dislocation injury mechanism, animals displayed no improvement in the grooming test, in contrast to the animals subjected to contusion or distraction injuries. These data indicate that different SCI mechanisms result in distinct patterns of histopathology and behavioral recovery. Understanding this heterogeneity may be important for the future development of therapeutic interventions that target specific neuropathology after SCI. PMID:26671448

  1. Enhanced adenoviral gene delivery to motor and dorsal root ganglion neurons following injection into demyelinated peripheral nerves.

    Science.gov (United States)

    Zhang, Yongjie; Zheng, Yiyan; Zhang, Yi Ping; Shields, Lisa B E; Hu, Xiaoling; Yu, Panpan; Burke, Darlene A; Wang, Heming; Jun, Cai; Byers, Jonathan; Whittemore, Scott R; Shields, Christopher B

    2010-08-15

    Injection of viral vectors into peripheral nerves may transfer specific genes into their dorsal root ganglion (DRG) neurons and motoneurons. However, myelin sheaths of peripheral axons block the entry of viral particles into nerves. We studied whether mild, transient peripheral nerve demyelination prior to intraneural viral vector injection would enhance gene transfer to target DRG neurons and motoneurons. The right sciatic nerve of C57BL/6 mice was focally demyelinated with 1% lysolecithin, and the left sciatic nerve was similarly injected with saline (control). Five days after demyelination, 0.5 microl of Ad5-GFP was injected into both sciatic nerves at the site of previous injection. The effectiveness of gene transfer was evaluated by counting GFP(+) neurons in the DRGs and ventral horns. After peripheral nerve demyelination, there was a fivefold increase in the number of infected DRG neurons and almost a 15-fold increase in the number of infected motoneurons compared with the control, nondemyelinated side. Focal demyelination reduced the myelin sheath barrier, allowing greater virus-axon contact. Increased CXADR expression on the demyelinated axons facilitated axoplasmic viral entry. No animals sustained any prolonged neurological deficits. Increased gene delivery into DRG neurons and motoneurons may provide effective treatment for amyotrophic lateral sclerosis, pain, and spinal cord injury.

  2. Epicritic Sensation in Cervical Spinal Cord Injury: Diagnostic Gains Beyond Testing Light Touch

    NARCIS (Netherlands)

    Velstra, Inge-Marie; Bolliger, Marc; Baumberger, Michael; Rietman, Johan Swanik; Curt, Armin

    2013-01-01

    Applied as a bedside test of gross dorsal column function, the testing of light touch (LT) sensation is of high clinical value in the diagnosis of human spinal cord injury (SCI). However, the assessment of overall dorsal column deficit by testing only LT may be limited, because the dorsal column pat

  3. Paresthesia thresholds in spinal cord stimulation: a comparison of theoretical results with clinical data

    NARCIS (Netherlands)

    Struijk, Johannes J.; Holsheimer, Jan; Barolat, Giancarlo; He, Jiping; Boom, Herman B.K.

    1993-01-01

    The potential distributions produced in the spinal cord and surrounding tissues by dorsal epidural stimulation at the midcervical, midthoracic, and low thoracic levels were calculated with the use of a volume conductor model. Stimulus thresholds of myelinated dorsal column fibers and dorsal root fib

  4. Effects of electrode configuration and geometry on fiber preference in spinal cord stimulation

    NARCIS (Netherlands)

    Holsheimer, Jan; Struijk, Johannes J.; Wesselink, Wilbert A.

    1996-01-01

    In contrast to the widespread assumption that dorsal column fibers are the primary targets of spinal cord stimulation by a dorsal epidural electrode, it appears that dorsal root fibers are recruited as well, and even preferentially under various conditions. This will, however, limit the coverage of

  5. Immunohistochemical localisation of the voltage gated potassium ion channel subunit Kv3.3 in the rat medulla oblongata and thoracic spinal cord.

    Science.gov (United States)

    Brooke, Ruth E; Atkinson, Lucy; Edwards, Ian; Parson, Simon H; Deuchars, Jim

    2006-01-27

    Voltage gated K+ channels (Kv) are a diverse group of channels important in determining neuronal excitability. The Kv superfamily is divided into 12 subfamilies (Kv1-12) and members of the Kv3 subfamily are highly abundant in the CNS, with each Kv3 gene (Kv3.1-Kv3.4) exhibiting a unique expression pattern. Since the localisation of Kv subunits is important in defining the roles they play in neuronal function, we have used immunohistochemistry to determine the distribution of the Kv3.3 subunit in the medulla oblongata and spinal cord of rats. Kv3.3 subunit immunoreactivity (Kv3.3-IR) was widespread but present only in specific cell populations where it could be detected in somata, dendrites and synaptic terminals. Labelled neurones were observed in the spinal cord in laminae IV and V, in the region of the central canal and in the ventral horn. In the medulla oblongata, labelled cell bodies were numerous in the spinal trigeminal, cuneate and gracilis nuclei whilst rarer in the lateral reticular nucleus, hypoglossal nucleus and raphe nucleus. Regions containing autonomic efferent neurones were predominantly devoid of labelling with only occasional labelled neurones being observed. Dual immunohistochemistry revealed that some Kv3.3-IR neurones in the ventral medullary reticular nucleus, spinal trigeminal nucleus, dorsal horn, ventral horn and central canal region were also immunoreactive for the Kv3.1b subunit. The presence of Kv3.3 subunits in terminals was confirmed by co-localisation of Kv3.3-IR with the synaptic vesicle protein SV2, the vesicular glutamate transporter VGluT2 and the glycine transporter GlyT2. Co-localisation of Kv3.3-IR was not observed with VGluT1, tyrosine hydroxylase, serotonin or choline acetyl transferase. Electron microscopy confirmed the presence of Kv3.3-IR in terminals and somatic membranes in ventral horn neurones, but not motoneurones. This study provides evidence supporting a role for Kv3.3 subunits in regulating neuronal excitability

  6. Retraining the injured spinal cord

    Science.gov (United States)

    Edgerton, V. R.; Leon, R. D.; Harkema, S. J.; Hodgson, J. A.; London, N.; Reinkensmeyer, D. J.; Roy, R. R.; Talmadge, R. J.; Tillakaratne, N. J.; Timoszyk, W.; Tobin, A.

    2001-01-01

    The present review presents a series of concepts that may be useful in developing rehabilitative strategies to enhance recovery of posture and locomotion following spinal cord injury. First, the loss of supraspinal input results in a marked change in the functional efficacy of the remaining synapses and neurons of intraspinal and peripheral afferent (dorsal root ganglion) origin. Second, following a complete transection the lumbrosacral spinal cord can recover greater levels of motor performance if it has been exposed to the afferent and intraspinal activation patterns that are associated with standing and stepping. Third, the spinal cord can more readily reacquire the ability to stand and step following spinal cord transection with repetitive exposure to standing and stepping. Fourth, robotic assistive devices can be used to guide the kinematics of the limbs and thus expose the spinal cord to the new normal activity patterns associated with a particular motor task following spinal cord injury. In addition, such robotic assistive devices can provide immediate quantification of the limb kinematics. Fifth, the behavioural and physiological effects of spinal cord transection are reflected in adaptations in most, if not all, neurotransmitter systems in the lumbosacral spinal cord. Evidence is presented that both the GABAergic and glycinergic inhibitory systems are up-regulated following complete spinal cord transection and that step training results in some aspects of these transmitter systems being down-regulated towards control levels. These concepts and observations demonstrate that (a) the spinal cord can interpret complex afferent information and generate the appropriate motor task; and (b) motor ability can be defined to a large degree by training.

  7. RUPTURED RUDIMENTARY HORN PREGNANCY OF UNICORNUATE UTERUS

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2015-06-01

    Full Text Available Unicornuate uterus can sometimes be associated with rudimentary horn. Pregnancy in a rudimentary horn is rare and usually ends up in rupture. Diagnosis is difficult and can be missed in routine ultrasound scan and is usually detected after rupture. We report a case of G1P1 with rudimentary horn pregnancy which raised suspicion on ultr asound and was later diagnosed by MR imaging. Patient refused termination and presented next day with shock. Laparotomy revealed ruptured right rudimentary horn pregnancy.

  8. Horn belief change: A contraction core

    CSIR Research Space (South Africa)

    Booth, R

    2010-08-01

    Full Text Available , and counterfactuals’, Artificial Intelligence, 57(2–3), 227–270, (1992). [5] S.O. Hansson, ‘Kernel contraction’, Journal of Symbolic Logic, 59(3), 845–859, (1994). [6] M. Langlois, R. Sloan, B. Szo¨re´nyi, and G. Thra´n, ‘Horn complements: Towards Horn... to its contraction counterpart. Delgrande [3] investigated two classes of contraction functions for Horn belief sets, viz. e-contraction and i-contraction, while Booth et al. [2] subsequently extended Delgrande’s work. A Horn clause has the form p1...

  9. Acrolein contributes to TRPA1 up-regulation in peripheral and central sensory hypersensitivity following spinal cord injury.

    Science.gov (United States)

    Park, Jonghyuck; Zheng, Lingxing; Acosta, Glen; Vega-Alvarez, Sasha; Chen, Zhe; Muratori, Breanne; Cao, Peng; Shi, Riyi

    2015-12-01

    Acrolein, an endogenous aldehyde, has been shown to be involved in sensory hypersensitivity after rat spinal cord injury (SCI), for which the pathogenesis is unclear. Acrolein can directly activate a pro-algesic transient receptor protein ankyrin 1 (TRPA1) channel that exists in sensory neurons. Both acrolein and TRPA1 mRNA are elevated post SCI, which contributes to the activation of TRPA1 by acrolein and consequently, neuropathic pain. In the current study, we further showed that, post-SCI elevation of TRPA1 mRNA exists not only in dorsal root ganglias but also in both peripheral (paw skin) and central endings of primary afferent nerves (dorsal horn of spinal cord). This is the first indication that pain signaling can be over-amplified in the peripheral skin by elevated expressions of TRPA1 following SCI, in addition over-amplification previously seen in the spinal cord and dorsal root ganglia. Furthermore, we show that acrolein alone, in the absence of physical trauma, could lead to the elevation of TRPA1 mRNA at various locations when injected to the spinal cord. In addition, post-SCI elevation of TRPA1 mRNA could be mitigated using acrolein scavengers. Both of these attributes support the critical role of acrolein in elevating TRPA1 expression through gene regulation. Taken together, these data indicate that acrolein is likely a critical causal factor in heightening pain sensation post-SCI, through both the direct binding of TRPA1 receptor, and also by boosting the expression of TRPA1. Finally, our data also further support the notion that acrolein scavenging may be an effective therapeutic approach to alleviate neuropathic pain after SCI. We propose that the trauma-mediated elevation of acrolein causes neuropathic pain through at least two mechanisms: acrolein stimulates the production of transient receptor protein ankyrin 1 (TRPA1) in both central and peripheral locations, and it activates TRPA1 channels directly. Therefore, acrolein appears to be a critical

  10. Miniaturization of planar horn motors

    Science.gov (United States)

    Sherrit, Stewart; Ostlund, Patrick N.; Chang, Zensheu; Bao, Xiaoqi; Bar-Cohen, Yoseph; Widholm, Scott E.; Badescu, Mircea

    2012-04-01

    There is a great need for compact, efficient motors for driving various mechanisms including robots or mobility platforms. A study is currently underway to develop a new type of piezoelectric actuators with significantly more strength, low mass, small footprint, and efficiency. The actuators/motors utilize piezoelectric actuated horns which have a very high power density and high electromechanical conversion efficiency. The horns are fabricated using our recently developed novel pre-stress flexures that make them thermally stable and increases their coupling efficiency. The monolithic design and integrated flexures that pre-stresses the piezoelectric stack eliminates the use of a stress bolt. This design allows embedding solid-state motors and actuators in any structure so that the only macroscopically moving parts are the rotor or the linear translator. The developed actuator uses a stack/horn actuation and has a Barth motor configuration, which potentially generates very large torque and speeds that do not require gearing. Finite element modeling and design tools were investigated to determine the requirements and operation parameters and the results were used to design and fabricate a motor. This new design offers a highly promising actuation mechanism that can potentially be miniaturized and integrated into systems and structures. It can be configured in many shapes to operate as multi-degrees of freedom and multi-dimensional motors/actuators including unidirectional, bidirectional, 2D and 3D. In this manuscript, we are reporting the experimental measurements from a bench top design and the results from the efforts to miniaturize the design using 2×2×2 mm piezoelectric stacks integrated into thin plates that are of the order of 3 × 3 × 0.2 cm.

  11. Potentiation of excitatory transmission in substantia gelatinosa neurons of rat spinal cord by inhibition of estrogen receptor alpha

    Directory of Open Access Journals (Sweden)

    Li Kai-Cheng

    2010-12-01

    Full Text Available Abstract Background It has been shown that estrogen is synthesized in the spinal dorsal horn and plays a role in modulating pain transmission. One of the estrogen receptor (ER subtypes, estrogen receptor alpha (ERα, is expressed in the spinal laminae I-V, including substantia gelatinosa (SG, lamina II. However, it is unclear how ERs are involved in the modulation of nociceptive transmission. Results In the present study, a selective ERα antagonist, methyl-piperidino-pyrazole (MPP, was used to test the potential functional roles of spinal ERα in the nociceptive transmission. Using the whole-cell patch-clamp technique, we examined the effects of MPP on SG neurons in the dorsal root-attached spinal cord slice prepared from adult rats. We found that MPP increased glutamatergic excitatory postsynaptic currents (EPSCs evoked by the stimulation of either Aδ- or C-afferent fibers. Further studies showed that MPP treatment dose-dependently increased spontaneous EPSCs frequency in SG neurons, while not affecting the amplitude. In addition, the PKC was involved in the MPP-induced enhancement of synaptic transmission. Conclusions These results suggest that the selective ERα antagonist MPP pre-synaptically facilitates the excitatory synaptic transmission to SG neurons. The nociceptive transmission evoked by Aδ- and C-fiber stimulation could be potentiated by blocking ERα in the spinal neurons. Thus, the spinal estrogen may negatively regulate the nociceptive transmission through the activation of ERα.

  12. Blocking mammalian target of rapamycin (mTOR improves neuropathic pain evoked by spinal cord injury

    Directory of Open Access Journals (Sweden)

    Wang Xiaoping

    2016-01-01

    Full Text Available Spinal cord injury (SCI is an extremely serious type of physical trauma observed in clinics. Neuropathic pain resulting from SCI has a lasting and significant impact on most aspects of daily life. Thus, a better understanding of the molecular pathways responsible for the cause of neuropathic pain observed in SCI is important to develop effective therapeutic agents and treatment strategies. Mammalian target of rapamycin (mTOR is a serine/threonine protein kinase that is well known for its critical roles in regulating protein synthesis and growth. Furthermore, compelling evidence supports the notion that widespread dysregulation of mTOR and its downstream pathways are involved in neuropathic pain. Thus, in this study we specifically examined the underlying mechanisms by which mTOR and its signaling pathways are involved in SCI-evoked neuropathic pain in a rat model. Overall, we demonstrated that SCI increased the protein expression of p-mTOR, and mTORmediated- phosphorylation of 4E–binding protein 4 (4E-BP1 and p70 ribosomal S6 protein kinase 1 (S6K1 in the superficial dorsal horn of the spinal cord. Also, we showed that blocking spinal mTOR by intrathecal injection of rapamycin significantly inhibited pain responses induced by mechanical and thermal stimulation. In addition, blocking spinal phosphatidylinositide 3-kinase (p-PI3K pathway significantly attenuated activities of p-mTOR pathways as well as mechanical and thermal hyperalgesia in SCI rats. Moreover, blocking mTOR and PI3K decreased the enhanced levels of substance P and calcitonin gene-related peptide (CGRP in the dorsal horn of SCI rats. We revealed specific signaling pathways leading to SCI-evoked neuropathic pain, including the activation of PI3K, mTOR and its downstream signaling pathways. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of neuropathic pain often observed in patients with SCI.

  13. Functional evaluation using several evoked spinal cord potentials in elderly patients with cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    Zhenglin Li

    2006-01-01

    spinal cord lesion with respect to the corticospinal tract in white matter. The abnormalities of Spinal-ESCPs were defined as marked reduction in the size of negative peak (reduction of over 50%). The most caudal intervertebral level showing abnormal Spinal-ESCPs was considered as the lower level of the spinal cord lesion with respect to the dorsal column pathway in white matter. The abnormalities of MN-ESCPs were defined as attenuation of the N13 amplitude,which was considered as the lesion level of the spinal cord with respect to the dorsal horn in gray matter. Radiological investigation: Lateral view of plain X-ray films was obtained in flexion and extension of the cervical spine. Instability of the cervical intervertebral level was determined as horizontal displacement of the vertebral body of over 3 mm.MAIN OUTCOME MEASURES: The results of examination of TCE-ESCPs, Spinal-ESCPs and MN-ESCPs in elderly patients with CSM.RESULTS: The 23 elderly patients with CSM were participated in the result analysis. ①TCE-ESCPs: The impairment of the corticospinal tract in white matter at single intervertebral level was revealed in 18 of 23 patients by recordings of TCE-ESCPs (sensitivity 78%). In the 18 patients, the lesion level was shown at the upper cervical segment in 14 patients (C3-4 n=10 and C4-5 n=4), and at the lower cervical segment in 4 patients (C5-6 n=4). ②Spinal-ESCPs: The impairment of the dorsal column pathway of white matter at single interverte bral level was revealed in 17 of 23 patients, by recordings of Spinal-ESCPs (sensitivity 74%). In the 17 patients, the lesion level was presented at the upper cervical segment in 14 patients (C3-4 n=10 and C4-5 n=4),and at the lower cervical segment in 3 patients (C5-6 n=3). ③MN-ESCPs: All patients revealed abnormal MN-ESCPs at one or more intervertebral levels (sensitivity 100%). The impairment at single intervertebral level was demonstrated in 17 patients, and the impairment at multiple intervertebral levels was

  14. Plasticity of TRPV1-expressing sensory neurons mediating autonomic dysreflexia following spinal cord injury

    Directory of Open Access Journals (Sweden)

    Leanne M Ramer

    2012-07-01

    Full Text Available Spinal cord injury (SCI triggers profound changes in visceral and somatic targets of sensory neurons below the level of injury. Despite this, little is known about the influence of injury to the spinal cord on sensory ganglia. One of the defining characteristics of sensory neurons is the size of their cell body: for example, nociceptors are smaller in size than mechanoreceptors or proprioceptors. In these experiments, we first used a comprehensive immunohistochemical approach to characterize the size distribution of sensory neurons after high- and low-thoracic SCI. Male Wistar rats (300g received a spinal cord transection (T3 or T10 or sham injury. At 30 days post-injury, dorsal root ganglia (DRGs and spinal cords were harvested and analyzed immunohistochemically. In a wide survey of primary afferents, only those expressing the capsaicin receptor (TRPV1 exhibited somal hypertrophy after T3 SCI. Hypertrophy only occurred caudal to SCI and was pronounced in ganglia far distal to SCI (i.e., in L4-S1 DRGs. Injury-induced hypertrophy was accompanied by a small expansion of central territory in the lumbar spinal dorsal horn and by evidence of TRPV1 upregulation. Importantly, hypertrophy of TRPV1-positive neurons was modest after T10 SCI. Given the specific effects of T3 SCI on TRPV1-positive afferents, we hypothesized that these afferents contribute to autonomic dysreflexia (AD. Rats with T3 SCI received vehicle or capsaicin via intrathecal injection at 2 or 28 days post-SCI; at 30 days, AD was assessed by recording intra-arterial blood pressure during colo-rectal distension. In both groups of capsaicin-treated animals, the severity of AD was dramatically reduced. While AD is multi-factorial in origin, TRPV1-positive afferents are clearly involved in AD elicited by colo-rectal distension. These findings implicate TRPV1-positive afferents in the initiation of AD and suggest that TRPV1 may be a therapeutic target for amelioration or prevention of AD

  15. 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...

  16. Yokukansan Improves Mechanical Allodynia through the Regulation of Interleukin-6 Expression in the Spinal Cord in Mice with Neuropathic Pain

    Directory of Open Access Journals (Sweden)

    Shigeru Ebisawa

    2015-01-01

    Full Text Available Neuropathic pain is caused by nerve injury. Yokukansan (Yi-Gan San, a traditional Japanese (Kampo medicine, has been widely used for neuropathic pain control. However, the analgesic mechanisms remain unknown. In this study, we investigated the analgesic mechanisms of yokukansan in a mouse model of neuropathic pain. Partial sciatic nerve ligation (PSL induced mechanical allodynia in mice. Repetitive oral administration of the extracts of yokukansan and the constituent herbal medicine Atractylodis Lanceae Rhizoma, but not Glycyrrhizae Radix, relieved mechanical allodynia in the PSL mice and inhibited the PSL-induced expression of interleukin- (IL- 6 mRNA in the spinal cord. Yokukansan did not attenuate intrathecal IL-6-induced mechanical allodynia. IL-6 immunoreactivity was detected in microglia and astrocytes in the spinal dorsal horn. These results suggest that yokukansan relieves mechanical allodynia in PSL mice by regulating the expression of IL-6 in astrocytes and/or microglia in the spinal cord. In addition, the components of Atractylodis Lanceae Rhizoma, one of the constituent herbal medicines in yokukansan, may play an important role in the regulation of IL-6 expression and neuropathic pain control.

  17. AA, sandwich line with magnetic horn

    CERN Document Server

    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. Spherical Horn Array for Wideband Propagation Measurements

    DEFF Research Database (Denmark)

    Franek, Ondrej; Pedersen, Gert Frølund

    2011-01-01

    A spherical array of horn antennas designed to obtain directional channel information and characteristics is introduced. A dual-polarized quad-ridged horn antenna with open flared boundaries and coaxial feeding for the frequency band 600 MHz–6 GHz is used as the element of the array. Matching...

  19. 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.

  20. 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... functions to be used for Horn partial meet e-contraction. Definition 3.2 (Horn e-Selection Functions) A partial meet Horn e-selection function σ is a function from P(P(LH)) to P(P(LH)) s.t. σ(H ↓e Φ) = {H} if H ↓e Φ = ∅, and ∅ 6= σ(H ↓eΦ) ⊆ H ↓e...

  1. Tyrosine phosphorylation of the N-Methyl-D-Aspartate receptor 2B subunit in spinal cord contributes to remifentanil-induced postoperative hyperalgesia: the preventive effect of ketamine

    Directory of Open Access Journals (Sweden)

    Cui Songqin

    2009-12-01

    Full Text Available Abstract Background Experimental and clinical studies showed that intraoperative infusionof remifentanil has been associated with postoperative hyperalgesia. Previous reports suggested that spinal N-methyl-D-aspartate (NMDA receptors may contribute to the development and maintenance of opioid-induced hyperalgesia. In the present study, we used a rat model of postoperative pain to investigate the role of tyrosine phosphorylation of NMDA receptor 2B (NR2B subunit in spinal cord in the postoperative hyperalgesia induced by remifentanil and the intervention of pretreatment with ketamine. Results Intraoperative infusion of remifentanil (0.04 mg/kg, subcutaneous significantly enhanced mechanical allodynia and thermal hyperalgesia induced by the plantar incision during the postoperative period (each lasting between 2 h and 48 h, which was attenuated by pretreatment with ketamine (10 mg/kg, subcutaneous. Correlated with the pain behavior changes, immunocytochemical and western blotting experiments in our study revealed that there was a marked increase in NR2B phosphorylation at Tyr1472 in the superficial dorsal horn after intraoperative infusion of remifentanil, which was attenuated by pretreatment with ketamine. Conclusions This study provides direct evidence that tyrosine phosphorylation of the NR2B at Tyr1472 in spinal dosal horn contributes to postoperative hyperalgesia induced by remifentanil and supports the potential therapeutic value of ketamine for improving postoperative hyperalgesia induced by remifentanil.

  2. N-METHYL-d-ASPARTATE RECEPTORS AND LARGE CONDUCTANCE CALCIUM-SENSITIVE POTASSIUM CHANNELS INHIBIT THE RELEASE OF OPIOID PEPTIDES THAT INDUCE μ-OPIOID RECEPTOR INTERNALIZATION IN THE RAT SPINAL CORD

    Science.gov (United States)

    SONG, B.; MARVIZÓN, J. C. G.

    2006-01-01

    Endogenous opioids in the spinal cord play an important role in nociception, but the mechanisms that control their release are poorly understood. To simultaneously detect all opioids able to activate the μ-opioid receptor, we measured μ-opioid receptor internalization in rat spinal cord slices stimulated electrically or chemically to evoke opioid release. Electrical stimulation of the dorsal horn in the presence of peptidase inhibitors produced μ-opioid receptor internalization in half of the μ-opioid receptor neurons. This internalization was rapidly abolished by N-methyl-d-aspartate (IC50=2 μM), and N-methyl-d-aspartate antagonists prevented this effect. μ-Opioid receptor internalization evoked by high K+ or veratridine was also inhibited by N-methyl-d-aspartate receptor activation. N-methyl-d-aspartate did not affect μ-opioid receptor internalization induced by exogenous endomorphins, confirming that the effect of N-methyl-d-aspartate was on opioid release. We hypothesized that this inhibition was mediated by large conductance Ca2+-sensitive K+ channels BK(Ca2+). Indeed, inhibition by N-methyl-d-aspartate was prevented by tetraethylammonium and by the selective BK(Ca2+) blockers paxilline, penitrem A and verruculogen. Paxilline did not increase μ-opioid receptor internalization in the absence of N-methyl-d-aspartate, indicating that it does not produce an increase in opioid release unrelated to the inhibition by N-methyl-d-aspartate. The BK(Ca2+) involved appears to be a subtype with slow association kinetics for iberiotoxin, which was effective only with long incubations. The BK(Ca2+) opener NS-1619 also inhibited the evoked μ-opioid receptor internalization, and iberiotoxin prevented this effect. We concluded that Ca2+ influx through N-methyl-d-aspartate receptors causes the opening of BK(Ca2+) and hyperpolarization in opioid-containing dorsal horn neurons, resulting in the inhibition of opioid release. Since μ-opioid receptors in the dorsal horn

  3. N-methyl-D-aspartate receptors and large conductance calcium-sensitive potassium channels inhibit the release of opioid peptides that induce mu-opioid receptor internalization in the rat spinal cord.

    Science.gov (United States)

    Song, B; Marvizón, J C G

    2005-01-01

    Endogenous opioids in the spinal cord play an important role in nociception, but the mechanisms that control their release are poorly understood. To simultaneously detect all opioids able to activate the mu-opioid receptor, we measured mu-opioid receptor internalization in rat spinal cord slices stimulated electrically or chemically to evoke opioid release. Electrical stimulation of the dorsal horn in the presence of peptidase inhibitors produced mu-opioid receptor internalization in half of the mu-opioid receptor neurons. This internalization was rapidly abolished by N-methyl-D-aspartate (IC50=2 microM), and N-methyl-D-aspartate antagonists prevented this effect. mu-Opioid receptor internalization evoked by high K+ or veratridine was also inhibited by N-methyl-D-aspartate receptor activation. N-methyl-D-aspartate did not affect mu-opioid receptor internalization induced by exogenous endomorphins, confirming that the effect of N-methyl-D-aspartate was on opioid release. We hypothesized that this inhibition was mediated by large conductance Ca2+-sensitive K+ channels BK(Ca2+). Indeed, inhibition by N-methyl-D-aspartate was prevented by tetraethylammonium and by the selective BK(Ca2+) blockers paxilline, penitrem A and verruculogen. Paxilline did not increase mu-opioid receptor internalization in the absence of N-methyl-D-aspartate, indicating that it does not produce an increase in opioid release unrelated to the inhibition by N-methyl-d-aspartate. The BK(Ca2+) involved appears to be a subtype with slow association kinetics for iberiotoxin, which was effective only with long incubations. The BK(Ca2+) opener NS-1619 also inhibited the evoked mu-opioid receptor internalization, and iberiotoxin prevented this effect. We concluded that Ca2+ influx through N-methyl-D-aspartate receptors causes the opening of BK(Ca2+) and hyperpolarization in opioid-containing dorsal horn neurons, resulting in the inhibition of opioid release. Since mu-opioid receptors in the dorsal horn

  4. Cord Blood

    Directory of Open Access Journals (Sweden)

    Saeed Abroun

    2014-05-01

    Full Text Available   Stem cells are naïve or master cells. This means they can transform into special 200 cell types as needed by body, and each of these cells has just one function. Stem cells are found in many parts of the human body, although some sources have richer concentrations than others. Some excellent sources of stem cells, such as bone marrow, peripheral blood, cord blood, other tissue stem cells and human embryos, which last one are controversial and their use can be illegal in some countries. Cord blood is a sample of blood taken from a newborn baby's umbilical cord. It is a rich source of stem cells, umbilical cord blood and tissue are collected from material that normally has no use following a child’s birth. Umbilical cord blood and tissue cells are rich sources of stem cells, which have been used in the treatment of over 80 diseases including leukemia, lymphoma and anemia as bone marrow stem cell potency.  The most common disease category has been leukemia. The next largest group is inherited diseases. Patients with lymphoma, myelodysplasia and severe aplastic anemia have also been successfully transplanted with cord blood. Cord blood is obtained by syringing out the placenta through the umbilical cord at the time of childbirth, after the cord has been detached from the newborn. Collecting stem cells from umbilical blood and tissue is ethical, pain-free, safe and simple. When they are needed to treat your child later in life, there will be no rejection or incompatibility issues, as the procedure will be using their own cells. In contrast, stem cells from donors do have these potential problems. By consider about cord blood potency, cord blood banks (familial or public were established. In IRAN, four cord blood banks has activity, Shariati BMT center cord blood bank, Royan familial cord blood banks, Royan public cord blood banks and Iranian Blood Transfusion Organ cord blood banks. Despite 50,000 sample which storage in these banks, but the

  5. GFAP and Fos immunoreactivity in lumbo-sacral spinal cord and medulla oblongata after chronic colonic inflammation in rats

    Institute of Scientific and Technical Information of China (English)

    Yi-Ning Sun; Jin-Yan Luo; Zhi-Ren Rao; Li Lan; Li Duan

    2005-01-01

    AIM:- To investigate the response of astrocytes and neurons in rat lumbo-sacral spinal cord and medulla oblongata induced by chronic colonic inflammation, and the relationship between them.METHODS: Thirty-three male Sprague-Dawley rats were randomly divided into two groups: experimental group (n = 17), colonic inflammation was induced by intra-luminal administration of trinitrobenzenesulfonic acid (TNBS);control group (n = 16), saline was administered intra-luminally.After 3, 7, 14, and 28 d of administration, the lumbo-sacral spinal cord and medulla oblongata were removed and processed for anti-glial fibrillary acidic protein (GFAP),Fos and GFAP/Fos immunohistochemistry.RESULTS: Activated astrocytes positive for GFAP were mainly distributed in the superficial laminae (laminae Ⅰ-Ⅱ)of dorsal horn, intermediolateral nucleus (laminae V),posterior commissural nucleus (laminae X) and anterolateral nucleus (laminae Ⅸ). Fos-IR (Fos-immunoreactive)neurons were mainly distributed in the deeper laminae of the spinal cord (laminae Ⅲ-Ⅳ, V-Ⅵ). In the medulla oblongata, both GFAP-IR astrocytes and Fos-IR neurons were mainly distributed in the medullary visceral zone (MVZ). The density of GFAP in the spinal cord of experimental rats was significantly higher after 3, 7, and 14 d of TNBS administration compared with the controls (50.4±16.8,29.2±6.5, 24.1±5.6, P<0.05). The density of GFAP in MVZ was significantly higher after 3 d of TNBS administration (34.3±2.5, P<0.05). After 28 d of TNBS administration,the density of GFAP in the spinal cord and MVZ decreased and became comparable to that of the controls (18.0±4.9,14.6±6.4, P>0.05).CONCLUSION: Astrocytes in spinal cord and medulla oblongata can be activated by colonic inflammation. The activated astrocytes are closely related to Fos-IR neurons.With the recovery of colonic inflammation, the activity of astrocytes in the spinal cord and medulla oblongata is reduced.

  6. Intracerebroventricular Administration of Nerve Growth Factor Induces Gliogenesis in Sensory Ganglia, Dorsal Root, and within the Dorsal Root Entry Zone

    OpenAIRE

    Schlachetzki, Johannes C.M.; Pizzo, Donald P.; Debbi A. Morrissette; Jürgen Winkler

    2015-01-01

    Previous studies indicated that intracerebroventricular administration of nerve growth factor (NGF) leads to massive Schwann cell hyperplasia surrounding the medulla oblongata and spinal cord. This study was designed to characterize the proliferation of peripheral glial cells, that is, Schwann and satellite cells, in the trigeminal ganglia and dorsal root ganglia (DRG) of adult rats during two weeks of NGF infusion using bromodeoxyuridine (BrdU) to label dividing cells. The trigeminal ganglia...

  7. 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

  8. 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....

  9. Olfactory coding in the honeybee lateral horn.

    Science.gov (United States)

    Roussel, Edith; Carcaud, Julie; Combe, Maud; Giurfa, Martin; Sandoz, Jean-Christophe

    2014-03-03

    Olfactory systems dynamically encode odor information in the nervous system. Insects constitute a well-established model for the study of the neural processes underlying olfactory perception. In insects, odors are detected by sensory neurons located in the antennae, whose axons project to a primary processing center, the antennal lobe. There, the olfactory message is reshaped and further conveyed to higher-order centers, the mushroom bodies and the lateral horn. Previous work has intensively analyzed the principles of olfactory processing in the antennal lobe and in the mushroom bodies. However, how the lateral horn participates in olfactory coding remains comparatively more enigmatic. We studied odor representation at the input to the lateral horn of the honeybee, a social insect that relies on both floral odors for foraging and pheromones for social communication. Using in vivo calcium imaging, we show consistent neural activity in the honeybee lateral horn upon stimulation with both floral volatiles and social pheromones. Recordings reveal odor-specific maps in this brain region as stimulations with the same odorant elicit more similar spatial activity patterns than stimulations with different odorants. Odor-similarity relationships are mostly conserved between antennal lobe and lateral horn, so that odor maps recorded in the lateral horn allow predicting bees' behavioral responses to floral odorants. In addition, a clear segregation of odorants based on pheromone type is found in both structures. The lateral horn thus contains an odor-specific map with distinct representations for the different bee pheromones, a prerequisite for eliciting specific behaviors.

  10. 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.

  11. AA, sandwich line with magnetic horn

    CERN Multimedia

    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.

  12. Effect of curcumin on apoptosis in spinal cord and dorsal root ganglion neurons in a rat model of diabetic neuropathic pain%姜黄素对糖尿病神经病理性痛大鼠脊髓和背根神经节神经细胞凋亡的影响

    Institute of Scientific and Technical Information of China (English)

    陈果; 黄葱葱; 党江坤; 连庆泉; 李军; 曹红

    2011-01-01

    目的 探讨姜黄素对糖尿病神经病理性痛(DNP)大鼠脊髓和背根神经节(DRG)神经细胞凋亡的影响.方法雄性SD大鼠108只,体重200~230 g,采用腹腔注射链唑霉素70 mg/kg的方法建立大鼠DNP模型.采用随机数字表法,将大鼠随机分为4组(n=27),正常对照组(C组):不制备DNP模型;DNP组;溶剂对照组(SC组)和姜黄素组(Cur组):于腹腔注射链唑霉素后14 d分别腹腔注射玉米油或姜黄素100 mg/kg(25 mg/ml),1次/d,连续2周.于链唑霉素给药前2 d、给药后14 d、姜黄素给药后3、7、14 d时测定机械缩足阈值(MWT)和热缩足潜伏期(TWL);于姜黄素给药后3、7、14 d时分别采用免疫组化法和Western blot法测定脊髓和DRG caspase-3和Bcl-2的表达水平,并测定神经细胞的凋亡率.结果 与C组比较,DNP组、SC组和Cur组MWT降低,TWL缩短,脊髓和DRG神经细胞凋亡率升高,caspase-3表达上调,Bcl-2表达下调(P<0.05);与DNP组比较,Cur组MWT升高,TWL延长,脊髓和DBG神经细胞凋亡率降低,caspase-3表达下调,Bcl-2表达上调(P<0.05),SC组差异无统计学意义(P>0.05).结论 姜黄素可通过抑制脊髓和DRG神经细胞凋亡,从而减轻大鼠DNP,其机制与抑制caspase-3水平、增强Bcl-2水平有关.%Objective To investigate the effect of curcumin on the apoptosis in spinal cord and dorsal root ganglion neurons in a rat model of diabetic neuropathic pain (DNP) . Methods One hundred and eight male SD rats weighing 200-230 g were randomly divided into 4 groups ( n = 27 each): control group (group C), DNP group, solvent control group (group SC) and curcumin group (group Cur) . Diabetes was induced with intraperitoneal streptozocin 70 mg/kg. Successful induction of diabetes was defined as blood glucose > 16.7 mmol/L. Curcumin and com oil 100 mg/kg (23 mg/ml) were given intraperitoneally once a day for 14 consecutive days starting from 14 days after administration of streptozocin in Cur and SC groups respectively

  13. Evidence for the Involvement of Spinal Cord-Inhibitory and Cytokines-Modulatory Mechanisms in the Anti-Hyperalgesic Effect of Hecogenin Acetate, a Steroidal Sapogenin-Acetylated, in Mice

    Directory of Open Access Journals (Sweden)

    Jullyana S.S. Quintans

    2014-06-01

    Full Text Available Hecogenin is a steroidal sapogenin largely drawn from the plants of the genus Agave, commonly known as ‘sisal’, and is one of the important precursors used by the pharmaceutical industry for the synthesis of steroid hormones. Hecogenin acetate (HA is a steroidal sapogenin-acetylated that produces antinociceptive activity. Thus, we evaluate the antihyperalgesic profile of HA in mice in inflammatory models, as well as its possible involvement with c-fos expression on spinal cord area and cytokines to produces analgesic profile. Acute pretreatment with HA (5, 10, or 20 mg/kg; i.p. inhibited the development of mechanical hyperalgesia induced by carrageenan, TNF-α, dopamine and PGE2. Additionally, the immunofluorescence data demonstrated that acute pretreatment with HA, at all doses tested, significantly inhibited Fos-like expression in the spinal cord dorsal horn normally observed after carrageenan-inflammation. Moreover, HA did not affect the motor performance of the mice as tested in the Rota rod test. This antinociceptive profile seems to be related, at least in part, to a reduction of pro-inflammatory cytokines, as IL-1β. The present results suggest that HA attenuates mechanical hyperalgesia by blocking the neural transmission of pain at the spinal cord levels and by cytokines-inhibitory mechanisms.

  14. Evidence for the involvement of spinal cord-inhibitory and cytokines-modulatory mechanisms in the anti-hyperalgesic effect of hecogenin acetate, a steroidal sapogenin-acetylated, in mice.

    Science.gov (United States)

    Quintans, Jullyana S S; Barreto, Rosana S S; de Lucca, Waldecy; Villarreal, Cristiane F; Kaneto, Carla M; Soares, Milena B P; Branco, Alexsandro; Almeida, Jackson R G S; Taranto, Alex G; Antoniolli, Angelo R; Freitas, Rivelilson M; Quintans, Lucindo J

    2014-06-19

    Hecogenin is a steroidal sapogenin largely drawn from the plants of the genus Agave, commonly known as 'sisal', and is one of the important precursors used by the pharmaceutical industry for the synthesis of steroid hormones. Hecogenin acetate (HA) is a steroidal sapogenin-acetylated that produces antinociceptive activity. Thus, we evaluate the antihyperalgesic profile of HA in mice in inflammatory models, as well as its possible involvement with c-fos expression on spinal cord area and cytokines to produces analgesic profile. Acute pretreatment with HA (5, 10, or 20 mg/kg; i.p.) inhibited the development of mechanical hyperalgesia induced by carrageenan, TNF-α, dopamine and PGE2. Additionally, the immunofluorescence data demonstrated that acute pretreatment with HA, at all doses tested, significantly inhibited Fos-like expression in the spinal cord dorsal horn normally observed after carrageenan-inflammation. Moreover, HA did not affect the motor performance of the mice as tested in the Rota rod test. This antinociceptive profile seems to be related, at least in part, to a reduction of pro-inflammatory cytokines, as IL-1β. The present results suggest that HA attenuates mechanical hyperalgesia by blocking the neural transmission of pain at the spinal cord levels and by cytokines-inhibitory mechanisms.

  15. 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

    then proceeds by applying the linearisation transformation and solver for linear Horn clauses to a sequence of sets of clauses with successively increasing dimension bound. The approach is then further developed by using a solution of clauses of lower dimension to (partially) linearise clauses of higher......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...

  16. 大鼠延髓背角内5-羟色胺、脑啡肽、γ-氨基丁酸、甘氨酸或P-物质能终末与钙结合蛋白阳性神经元间的联系%CONNECTIONS BETWEEN SEROTONERGIC, ENKEPHALINERGIC,GABAERGIC, GLYCINERGIC, SUBSTANCE P-ERGIC TERMINALS AND CALCIUM BINDING PROTEINS-CONTAINING NOCICEPTIVE NEURONS IN RAT MEDULLARY DORSAL HORN

    Institute of Scientific and Technical Information of China (English)

    李辉; 吴乐; 李云庆

    2006-01-01

    CB(calbindin-D28k),CR(calretinin)和PV(parvalbumin)是最常见的3种钙结合蛋白(calcium-binding proteins,CaBPs).本研究首先观察了面口部给予伤害性刺激诱发大鼠延髓背角(又称三叉神经脊束核尾侧亚核)神经元表达FOS蛋白的状况;然后通过免疫荧光组织化学技术检测这些神经元内是否含有CaBPs(CB、CR和PV);最后通过免疫荧光和免疫电镜染色技术观察5-HT、GABA、甘氨酸转运体2(glycine transporter 2,GlvT2)、脑啡肽(enkephalin,ENK)或SP与CaBPs/FOS双标神经元间的联系.在光镜下可观察到:(1)FOS阳性神经元在延髓背角各层均有分布,以Ⅱ层最为密集;(2)大多数CB、CR或PV阳性神经元位于Ⅱ层,余者分布在Ⅰ层和Ⅲ层;(3)5-HT、GABA、GlyT2,ENK及SP阳性纤维和终末主要位于延髓背角浅层(4)部分FOS阳性神经元同时呈CB、CR或PV阳性;(5)5-HT、GABA、GlyT2或ENK阳性终末分别与FOS/CB、FOS/CR或FOS/PV双标神经元形成密切接触;(6)SP阳性终末与5-HT、GABA、GlyT2或ENK阳性终末同时与CB、CR或PV阳性神经元形成密切接触.在电镜下观察到5-HT、GABA、GlyT2或ENK阳性终末与CB、CR或PV阳性神经元主要形成对称型(抑制性)突触联系.这些结果提示在大鼠延髓背角,5-HT、GABA、甘氨酸或ENK可能通过抑制含钙结合蛋白的伤害性感受神经元来调节面口部伤害性信息的传递.%Calbindin-D28k (CB), calretinin (CR) and parvalbumin (PV) are the most common calcium-binding proteins (CaBPs). In the present study, FOS immunoreactivity was first induced in neurons of the medullary dorsal horn (MDH) of the rat by noxious orofacial stimulation; CaBPs (CB, CR and PV) in these neurons were then identified by imumunofluorescence histochemistry, and then, in addition, afferents to CaBPs/FOS double-labeled neurons were showed by immunofluorescence histochemical staining for the γ-aminobutyric acid (GABA) , glycine transporter 2 (GlyT2) , enkephalin (ENK) , serotonin

  17. ERK MAP kinase activation in spinal cord regulates phosphorylation of Cdk5 at serine 159 and contributes to peripheral inflammation induced pain/hypersensitivity.

    Directory of Open Access Journals (Sweden)

    Xiaoqin Zhang

    Full Text Available Cyclin-dependent kinase 5 is a proline-directed serine/threonine kinase and its activity participates in the regulation of nociceptive signaling. Like binding with the activators (P35 or P25, the phosphorylation of Cdk5 plays a critical role in Cdk5 activation. However, it is still unclear whether Cdk5 phosphorylation (p-Cdk5 contributes to pain hyperalgesia. The aim of our current study was to identify the roles of p-Cdk5 and its upstream regulator in response to peripheral inflammation. Complete Freund's adjuvant (CFA injection induced acute peripheral inflammation and heat hyperalgesia, which was accompanied by sustained increases in phospho-ERK1/2 (p-ERK1/2 and phospho-Cdk5(S159 (p-Cdk5(S159 in the spinal cord dorsal horn (SCDH. CFA-induced p-ERK primarily colocalized with p-Cdk5(S159 in superficial dorsal horn neurons. Levels in p-ERK and p-Cdk5 were also increased in the 2(nd phase of hyperalgesia induced by formalin injection, which can produce acute and tonic inflammatory pain. MAP kinase kinase inhibitor U0126 intrathecal delivery significantly suppressed the elevation of p-Cdk5(S159, Cdk5 activity and pain response behavior (Heat hyperalgesia, Spontaneous flinches induced by CFA or formalin injection. Cdk5 inhibitor roscovitine intrathecal administration also suppressed CFA-induced heat hyperalgesia and Cdk5 phosphorylation, but did not attenuate ERK activation. All these findings suggested that p-Cdk5(S159 regulated by ERK pathway activity may be a critical mechanism involved in the activation of Cdk5 in nociceptive spinal neurons contributes to peripheral inflammatory pain hypersensitivity.

  18. Differential astroglial responses in the spinal cord of rats submitted to a sciatic nerve double crush treated with local injection of cultured Schwann cell suspension or lesioned spinal cord extract: implications on cell therapy for nerve repair Respostas astrocitárias na medula espinal do rato submetido ao esmagamento duplo do nervo ciático e tratado com injeção local de suspensão de células de Schwann cultivadas ou de extrato de medula espinal lesada: implicações na terapia celular para o reparo do nervo

    Directory of Open Access Journals (Sweden)

    João Gabriel Martins Dallo

    2007-12-01

    Full Text Available PURPOSE: Reactive astrocytes are implicated in several mechanisms after central or peripheral nervous system lesion, including neuroprotection, neuronal sprouting, neurotransmission and neuropathic pain. Schwann cells (SC, a peripheral glia, also react after nerve lesion favoring wound/repair, fiber outgrowth and neuronal regeneration. We investigated herein whether cell therapy for repair of lesioned sciatic nerve may change the pattern of astroglial activation in the spinal cord ventral or dorsal horn of the rat. METHODS: Injections of a cultured SC suspension or a lesioned spinal cord homogenized extract were made in a reservoir promoted by a contiguous double crush of the rat sciatic nerve. Local injection of phosphate buffered saline (PBS served as control. One week later, rats were euthanized and spinal cord astrocytes were labeled by immunohistochemistry and quantified by means of quantitative image analysis. RESULTS: In the ipsilateral ventral horn, slight astroglial activations were seen after PBS or SC injections, however, a substantial activation was achieved after cord extract injection in the sciatic nerve reservoir. Moreover, SC suspension and cord extract injections were able to promote astroglial reaction in the spinal cord dorsal horn bilaterally. Conclusion: Spinal cord astrocytes react according to repair processes of axotomized nerve, which may influence the functional outcome. The event should be considered during the neurosurgery strategies.OBJETIVO: Astrócitos reativos participam de vários mecanismos após lesões do sistema nervoso central e periférico, os quais incluem neuroproteção, brotamento neuronal, neurotransmissão e dor neuropática. As células de Schwann (CS, um tipo de glia periférica, também reagem com a lesão do nervo, podendo interferir com o reparo e cicatrização, crescimento de fibras e regeneração neuronais. Investigamos aqui a possibilidade da terapia celular para o reparo do nervo ci

  19. A Horn-to-Horn Power Transmission System at Terahertz Frequencies

    Science.gov (United States)

    Gonzalez, A.; Uzawa, Y.; Fujii, Y.; Kaneko, K.; Kuroiwa, K.

    2011-11-01

    A horn-to-horn power transmission system at Terahertz frequencies has been designed and tested. Power is generated at microwave frequencies and then frequency multiplied to the band 799-938 GHz. The resultant signal is radiated by a diagonal horn and redirected by two identical elliptical mirrors to another diagonal horn located far away. Useful design equations have been derived for the proposed system. The concept has been proven by careful measurements and utilized for the local oscillator injection in the Atacama Large Millimeter Array (ALMA) Band-10 receiver.

  20. Dissociation of the dorsal-cactus complex and phosphorylation of the dorsal protein correlate with the nuclear localization of dorsal

    OpenAIRE

    1993-01-01

    The formation of dorsal-ventral polarity in Drosophila requires the asymmetric nuclear localization of the dorsal protein along the D/V axis. This process is regulated by the action of the dorsal group genes and cactus. We show that dorsal and cactus are both phosphoproteins that form a stable cytoplasmic complex, and that the cactus protein is stabilized by its interaction with dorsal. The dorsal-cactus complex dissociates when dorsal is targeted to the nucleus. While the phosphorylation of ...

  1. 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.

  2. 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.

  3. Activation of TRPV1 by capsaicin induces functional Kinin B1 receptor in rat spinal cord microglia

    Directory of Open Access Journals (Sweden)

    Talbot Sébastien

    2012-01-01

    Full Text Available Abstract Background The kinin B1 receptor (B1R is upregulated by pro-inflammatory cytokines and oxydative stress, which are enhanced by transient receptor potential vanilloid subtype 1 (TRPV1 activation. To examine the link between TRPV1 and B1R in inflammatory pain, this study aimed to determine the ability of TRPV1 to regulate microglial B1R expression in the spinal cord dorsal horn, and the underlying mechanism. Methods B1R expression (mRNA, protein and binding sites was measured in cervical, thoracic and lumbar spinal cord in response to TRPV1 activation by systemic capsaicin (1-50 mg/kg, s.c in rats pre-treated with TRPV1 antagonists (capsazepine or SB-366791, the antioxidant N-acetyl-L-cysteine (NAC, or vehicle. B1R function was assessed using a tail-flick test after intrathecal (i.t. injection of a selective B1R agonist (des-Arg9-BK, and its microglial localization was investigated by confocal microscopy with the selective fluorescent B1R agonist, [Nα-bodipy]-des-Arg9-BK. The effect of i.t. capsaicin (1 μg/site was also investigated. Results Capsaicin (10 to 50 mg/kg, s.c. enhanced time-dependently (0-24h B1R mRNA levels in the lumbar spinal cord; this effect was prevented by capsazepine (10 mg/kg, i.p.; 10 μg/site, i.t. and SB-366791 (1 mg/kg, i.p.; 30 μg/site, i.t.. Increases of B1R mRNA were correlated with IL-1β mRNA levels, and they were significantly less in cervical and thoracic spinal cord. Intrathecal capsaicin (1 μg/site also enhanced B1R mRNA in lumbar spinal cord. NAC (1 g/kg/d × 7 days prevented B1R up-regulation, superoxide anion production and NF-kB activation induced by capsaicin (15 mg/kg. Des-Arg9-BK (9.6 nmol/site, i.t. decreased by 25-30% the nociceptive threshold at 1 min post-injection in capsaicin-treated rats (10-50 mg/kg while it was without effect in control rats. Des-Arg9-BK-induced thermal hyperalgesia was blocked by capsazepine, SB-366791 and by antagonists/inhibitors of B1R (SSR240612, 10 mg/kg, p

  4. Planar Rotary Piezoelectric Motor Using Ultrasonic Horns

    Science.gov (United States)

    Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph; Geiyer, Daniel; Ostlund, Patrick N.; Allen, Phillip

    2011-01-01

    A motor involves a simple design that can be embedded into a plate structure by incorporating ultrasonic horn actuators into the plate. The piezoelectric material that is integrated into the horns is pre-stressed with flexures. Piezoelectric actuators are attractive for their ability to generate precision high strokes, torques, and forces while operating under relatively harsh conditions (temperatures at single-digit K to as high as 1,273 K). Electromagnetic motors (EM) typically have high rotational speed and low torque. In order to produce a useful torque, these motors are geared down to reduce the speed and increase the torque. This gearing adds mass and reduces the efficiency of the EM. Piezoelectric motors can be designed with high torques and lower speeds directly without the need for gears. Designs were developed for producing rotary motion based on the Barth concept of an ultrasonic horn driving a rotor. This idea was extended to a linear motor design by having the horns drive a slider. The unique feature of these motors is that they can be designed in a monolithic planar structure. The design is a unidirectional motor, which is driven by eight horn actuators, that rotates in the clockwise direction. There are two sets of flexures. The flexures around the piezoelectric material are pre-stress flexures and they pre-load the piezoelectric disks to maintain their being operated under compression when electric field is applied. The other set of flexures is a mounting flexure that attaches to the horn at the nodal point and can be designed to generate a normal force between the horn tip and the rotor so that to first order it operates independently and compensates for the wear between the horn and the rotor.

  5. Respiratory interneurones in the thoracic spinal cord of the cat.

    Science.gov (United States)

    Kirkwood, P A; Munson, J B; Sears, T A; Westgaard, R H

    1988-01-01

    1. The discharges of spontaneously firing neurones, whose activity was modulated in phase with the central respiratory cycle, were recorded in the thoracic ventral horn (T3-T9) of anaesthetized, paralysed cats. 2. Out of 310 neurones, forty-six were positively identified as motoneurones by antidromic activation or spike-triggered averaging, fifty-four were positively identified as interneurones by antidromic activation from other spinal cord segments and ninety were indirectly identified as interneurones by virtue of their positions or firing rates as compared to the motoneurones. 3. Units were classified as inspiratory (64%), expiratory (25%) or post-inspiratory (7%) according to the times of their maximum firing rates. The remaining 4% consisted of units whose discharges were either strongly locked to the respiratory pump cycle or did not fit into the other categories. All but one of the motoneurones were classified as inspiratory or expiratory. 4. Inspiratory and expiratory units were further classified as early, late or tonic according to the starting times of their discharges in the respiratory cycle. The interneurones (both positively and indirectly identified) included more of the early and tonic categories and more fast-firing units than did the motoneurones in both the inspiratory and expiratory groups. 5. The locations of the motoneurones corresponded to the known positions of the intercostal and interchondral motor nuclei, including clear segregation of inspiratory and expiratory populations. The locations of neither the interneurones nor the unidentified units were segregated according to their firing patterns. These neurones were concentrated in the medial half of the ventral horn and were found generally more dorsally than the positions of the motoneurones, though their positions overlapped considerably with this group. 6. The axons of the positively identified interneurones were identified from one to five segments caudally and mostly contralaterally

  6. Agenesis of the dorsal pancreas

    Institute of Scientific and Technical Information of China (English)

    Lale Pasaoglu; Murat Vural; Hatice Gul Hatipoglu; Gokce Tereklioglu; Suha Koparal

    2008-01-01

    Developmental anomalies of the pancreas have been reported but dorsal pancreatic agenesis is an extremely rare entity. We report an asymptomatic 62-year-old woman with complete agenesis of the dorsal pancreas.Abdominal computed tomography (CT) revealed a normal pancreatic head, but pancreatic body and tail were not visualized. Magnetic resonance imaging (MRI)findings were similar to CT. At magnetic resonance cholangiopancreatography (MRCP), the major pancreatic duct was short and the dorsal pancreatic duct was not visualized. The final diagnosis was dorsal pancreatic agenesis.

  7. Imaging corticospinal tract connectivity in injured rat spinal cord using manganese-enhanced MRI

    Directory of Open Access Journals (Sweden)

    Bilgen Mehmet

    2006-11-01

    Full Text Available Abstract Background Manganese-enhanced MRI (MEI offers a novel neuroimaging modality to trace corticospinal tract (CST in live animals. This paper expands this capability further and tests the utility of MEI to image axonal fiber connectivity in CST of injured spinal cord (SC. Methods A rat was injured at the thoracic T4 level of the SC. The CST was labeled with manganese (Mn injected intracortically at two weeks post injury. Next day, the injured SC was imaged using MEI and diffusion tensor imaging (DTI modalities. Results In vivo MEI data obtained from cervical SC confirmed that CST was successfully labeled with Mn. Ex vivo MEI data obtained from excised SC depicted Mn labeling of the CST in SC sections caudal to the lesion, which meant that Mn was transported through the injury, possibly mediated by viable CST fibers present at the injury site. Examining the ex vivo data from the injury epicenter closely revealed a thin strip of signal enhancement located ventrally between the dorsal horns. This enhancement was presumably associated with the Mn accumulation in these intact fibers projecting caudally as part of the CST. Additional measurements with DTI supported this view. Conclusion Combining these preliminary results collectively demonstrated the feasibility of imaging fiber connectivity in experimentally injured SC using MEI. This approach may play important role in future investigations aimed at understanding the neuroplasticity in experimental SCI research.

  8. 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...

  9. Modulation of spinal cord synaptic activity by tumor necrosis factor α in a model of peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Spicarova Diana

    2011-12-01

    Full Text Available Abstract Background The cytokine tumor necrosis factor α (TNFα is an established pain modulator in both the peripheral and central nervous systems. Modulation of nociceptive synaptic transmission in the spinal cord dorsal horn (DH is thought to be involved in the development and maintenance of several pathological pain states. Increased levels of TNFα and its receptors (TNFR in dorsal root ganglion (DRG cells and in the spinal cord DH have been shown to play an essential role in neuropathic pain processing. In the present experiments the effect of TNFα incubation on modulation of primary afferent synaptic activity was investigated in a model of peripheral neuropathy. Methods Spontaneous and miniature excitatory postsynaptic currents (sEPSC and mEPSCs were recorded in superficial DH neurons in acute spinal cord slices prepared from animals 5 days after sciatic nerve transection and in controls. Results In slices after axotomy the sEPSC frequency was 2.8 ± 0.8 Hz, while neurons recorded from slices after TNFα incubation had significantly higher sEPSC frequency (7.9 ± 2.2 Hz. The effect of TNFα treatment was smaller in the slices from the control animals, where sEPSC frequency was 1.2 ± 0.2 Hz in slices without and 2.0 ± 0.5 Hz with TNFα incubation. Tetrodotoxin (TTX application in slices from axotomized animals and after TNFα incubation decreased the mEPSC frequency to only 37.4 ± 6.9% of the sEPSC frequency. This decrease was significantly higher than in the slices without the TNFα treatment (64.4 ± 6.4%. TTX application in the control slices reduced the sEPSC frequency to about 80% in both TNFα untreated and treated slices. Application of low concentration TRPV1 receptors endogenous agonist N-oleoyldopamine (OLDA, 0.2 μM in slices after axotomy induced a significant increase in mEPSC frequency (175.9 ± 17.3%, similar to the group with TNFα pretreatment (158.1 ± 19.5%. Conclusions Our results indicate that TNFα may enhance

  10. Chemokine contribution to neuropathic pain: respective induction of CXCL1 and CXCR2 in spinal cord astrocytes and neurons.

    Science.gov (United States)

    Zhang, Zhi-Jun; Cao, De-Li; Zhang, Xin; Ji, Ru-Rong; Gao, Yong-Jing

    2013-10-01

    Recent studies have indicated an important role of chemokines such as CCL2 in the development of chronic pain. However, the distinct roles of different chemokines in the development and maintenance of neuropathic pain and in their interactions with neurons have not been clearly elucidated. We found that spinal nerve ligation (SNL) not only induced persistent neuropathic pain symptoms, including mechanical allodynia and heat hyperalgesia, but also produced sustained CXCL1 upregulation in the spinal cord. Double staining of immunofluorescence and in situ hybridization revealed that CXCL1 was primarily induced in spinal astrocytes. In cultured astrocytes, tumor necrosis factor-α induced robust CXCL1 expression via the activation of the c-jun N-terminal kinase. Intrathecal administration of CXCL1 neutralizing antibody transiently reduced SNL-induced pain hypersensitivity, suggesting an essential role of CXCL1 in neuropathic pain sensitization. In particular, intraspinal delivery of CXCL1 shRNA lentiviral vectors, either before or after SNL, persistently attenuated SNL-induced pain hypersensitivity. Spinal application of CXCL1 not only elicited pain hypersensitivity but also induced rapid neuronal activation, as indicated by the expression of phosphorylated extracellular signal-regulated kinase and cAMP response element binding protein, and c-Fos in spinal cord neurons. Interestingly, CXCR2, the primary receptor of CXCL1, was upregulated in dorsal horn neurons after SNL, and the CXCR2 antagonist SB225002 completely blocked the CXCL1-induced heat hyperalgesia. SB225002 also attenuated SNL-induced pain hypersensitivity. Collectively, our results have demonstrated a novel form of chemokine-mediated glial-neuronal interaction in the spinal cord that can drive neuropathic pain. Inhibition of the CXCL1-CXCR2 signaling may offer a new therapy for neuropathic pain management.

  11. Short-term anesthesia inhibits formalin-induced extracellular signal-regulated kinase (ERK) activation in the rostral anterior cingulate cortex but not in the spinal cord.

    Science.gov (United States)

    Tochiki, Keri K; Maiarù, Maria; Miller, James R C; Hunt, Stephen P; Géranton, Sandrine M

    2015-08-14

    The rostral anterior cingulate cortex (rACC) has been implicated in the negative affective response to injury, and importantly, it has been shown that activation of extracellular signal-regulated kinase (ERK) signaling in the rACC contributes to the full expression of the affective component of pain in rodents. In this study, we investigated whether administration of anesthesia at the time of injury could reduce phosphorylated-ERK (PERK) expression in the rACC, which might eliminate the negative affective component of noxious stimulation. Intraplantar hindpaw formalin stimulation, an aversive event in the awake animal, was given with or without general isoflurane anesthesia, and PERK expression was subsequently quantified in the rACC using immunohistochemistry. Furthermore, as numerous studies have demonstrated the importance of spinal ERK signaling in the regulation of nociceptive behaviour, we also examined PERK in the superficial dorsal horn of the spinal cord. Formalin injection with and without short-term (anesthesia induced the same level of PERK expression in spinal cord laminae I-II. However, PERK expression was significantly inhibited across all laminae of the rACC in animals anesthetized during formalin injection. The effect of anesthesia was such that levels of PERK were the same in formalin and sham treated anesthesized animals. This study is the first to demonstrate that isoflurane anesthesia can inhibit formalin-induced PERK in the rACC and therefore might eliminate the unpleasantness of restraint associated with awake hindpaw injection.

  12. Intracerebroventricular administration of nerve growth factor induces gliogenesis in sensory ganglia, dorsal root, and within the dorsal root entry zone.

    Science.gov (United States)

    Schlachetzki, Johannes C M; Pizzo, Donald P; Morrissette, Debbi A; Winkler, Jürgen

    2014-01-01

    Previous studies indicated that intracerebroventricular administration of nerve growth factor (NGF) leads to massive Schwann cell hyperplasia surrounding the medulla oblongata and spinal cord. This study was designed to characterize the proliferation of peripheral glial cells, that is, Schwann and satellite cells, in the trigeminal ganglia and dorsal root ganglia (DRG) of adult rats during two weeks of NGF infusion using bromodeoxyuridine (BrdU) to label dividing cells. The trigeminal ganglia as well as the cervical and lumbar DRG were analyzed. Along the entire neuraxis a small number of dividing cells were observed within these regions under physiological condition. NGF infusion has dramatically increased the generation of new cells in the neuronal soma and axonal compartments of sensory ganglia and along the dorsal root and the dorsal root entry zone. Quantification of BrdU positive cells within sensory ganglia revealed a 2.3- to 3-fold increase in glial cells compared to controls with a similar response to NGF for the different peripheral ganglia examined. Immunofluorescent labeling with S100β revealed that Schwann and satellite cells underwent mitosis after NGF administration. These data indicate that intracerebroventricular NGF infusion significantly induces gliogenesis in trigeminal ganglia and the spinal sensory ganglia and along the dorsal root entry zone as well as the dorsal root.

  13. Intracerebroventricular Administration of Nerve Growth Factor Induces Gliogenesis in Sensory Ganglia, Dorsal Root, and within the Dorsal Root Entry Zone

    Directory of Open Access Journals (Sweden)

    Johannes C. M. Schlachetzki

    2014-01-01

    Full Text Available Previous studies indicated that intracerebroventricular administration of nerve growth factor (NGF leads to massive Schwann cell hyperplasia surrounding the medulla oblongata and spinal cord. This study was designed to characterize the proliferation of peripheral glial cells, that is, Schwann and satellite cells, in the trigeminal ganglia and dorsal root ganglia (DRG of adult rats during two weeks of NGF infusion using bromodeoxyuridine (BrdU to label dividing cells. The trigeminal ganglia as well as the cervical and lumbar DRG were analyzed. Along the entire neuraxis a small number of dividing cells were observed within these regions under physiological condition. NGF infusion has dramatically increased the generation of new cells in the neuronal soma and axonal compartments of sensory ganglia and along the dorsal root and the dorsal root entry zone. Quantification of BrdU positive cells within sensory ganglia revealed a 2.3- to 3-fold increase in glial cells compared to controls with a similar response to NGF for the different peripheral ganglia examined. Immunofluorescent labeling with S100β revealed that Schwann and satellite cells underwent mitosis after NGF administration. These data indicate that intracerebroventricular NGF infusion significantly induces gliogenesis in trigeminal ganglia and the spinal sensory ganglia and along the dorsal root entry zone as well as the dorsal root.

  14. Phrenic nerve afferents elicited cord dorsum potential in the cat cervical spinal cord

    Directory of Open Access Journals (Sweden)

    Davenport Paul W

    2005-05-01

    Full Text Available Abstract Background The diaphragm has sensory innervation from mechanoreceptors with myelinated axons entering the spinal cord via the phrenic nerve that project to the thalamus and somatosensory cortex. It was hypothesized that phrenic nerve afferent (PnA projection to the central nervous system is via the spinal dorsal column pathway. Results A single N1 peak of the CDP was found in the C4 and C7 spinal segments. Three peaks (N1, N2, and N3 were found in the C5 and C6 segments. No CDP was recorded at C8 dorsal spinal cord surface in cats. Conclusion These results demonstrate PnA activation of neurons in the cervical spinal cord. Three populations of myelinated PnA (Group I, Group II, and Group III enter the cat's cervical spinal segments that supply the phrenic nerve

  15. Acute central cord syndrome: injury mechanisms and stress features.

    Science.gov (United States)

    Li, Xin-Feng; Dai, Li-Yang

    2010-09-01

    Numerical techniques were used to study the mechanisms of acute central cord syndrome. To analyze the features of stress distribution in the cervical cord under different injury conditions using finite element model of the cervical cord and to improve the understanding of the possible pathogenesis of acute central cord syndrome. Acute central cord spinal injury was initially attributed to hemorrhagic damage to the central portion of the spinal cord, but recent histopathologic studies showed that it was predominantly a white matter injury. The precise anatomic location of neuronal injury and the etiology of the clinical manifestation were poorly understood. Cervical cord injury was simulated using a finite element model of the cervical enlargement described previously, with the model loaded under 3 traumatic postures: neutral, flexion, and extension. Five traumatic conditions were simulated and analyzed: hyperextension with the pinch force directed to the anterior (A) or posterior (B); flexion injuries (C), vertical compression with the pinch force directed to the anterior (D) or posterior (E). After simulation, several representative cross-sections of each traumatic pattern were selected. In each cross-section, the average von Mises stress of 9 regions, such as anterior funiculus, lateral part of the lateral funiculus, medial part of the lateral funiculus, lateral part of the posterior funiculus, medial part of the posterior funiculus, anterior horn, the bottom of anterior horn, the cervix cornu posterioris, the caput cornu posterioris, and the apex cornu posterioris was recorded. High localized stress occurred at the portion under compression injury and the level above it. High localized stress tended to occur at the lateral part of the anterior horn motor neurons innervating the hand muscles in traumatic conditions A and D. Under conditions A, D, and E, the average localized stress at the anterior and posterior horn of the gray matter was higher than that at the

  16. Interneurones in pathways from group II muscle afferents in sacral segments of the feline spinal cord.

    Science.gov (United States)

    Jankowska, E; Riddell, J S

    1994-03-15

    1. Properties of dorsal horn interneurones that process information from group II muscle afferents in the sacral segments of the spinal cord have been investigated in the cat using both intracellular and extracellular recording. 2. The interneurones were excited by group II muscle afferents and cutaneous afferents but not by group I muscle afferents. They were most effectively excited by group II afferents of the posterior biceps, semitendinosus, triceps surae and quadriceps muscle nerves and by cutaneous afferents running in the cutaneous femoris, pudendal and sural nerves. The earliest synaptic actions were evoked monosynaptically and were very tightly locked to the stimuli. 3. EPSPs evoked monosynaptically by group II muscle afferents and cutaneous afferents of the most effective nerves were often cut short by disynaptic IPSPs. As a consequence of this negative feedback the EPSPs gave rise to single or double spike potentials and only a minority of interneurones responded with repetitive discharges. However, the neurones that did respond repetitively did so at a very high frequency of discharges (0.8-1.2 ms intervals between the first 2-3 spikes). 4. Sacral dorsal horn group II interneurones do not appear to act directly upon motoneurones because: (i) these interneurones are located outside the area within which last order interneurones have previously been found and (ii) the latencies of PSPs evoked in motoneurones by stimulation of the posterior biceps and semitendinosus, cutaneous femoris and pudendal nerves (i.e. the main nerves providing input to sacral interneurones) are compatible with a tri- but not with a disynaptic coupling. Spatial facilitation of EPSPs and IPSPs following synchronous stimulation of group II and cutaneous afferents of these nerves shows, however, that sacral interneurones may induce excitation or inhibition of motoneurones via other interneurones. 5. Comparison of the properties of group II interneurones in the sacral segments with

  17. Ultrastructure of pacinian corpuscle primary afferent terminals in the cat spinal cord.

    Science.gov (United States)

    Semba, K; Masarachia, P; Malamed, S; Jacquin, M; Harris, S; Egger, M D

    1984-06-04

    The glabrous skin of the hindlimb of the cat contains 3 types of low-threshold mechanoreceptors: Pacinian corpuscles (PC), and slowly and rapidly adapting receptors. In the present study, 12 primary afferent fibers transmitting impulses from PC were injected intra-axonally with horseradish peroxidase (HRP) in the spinal cord to examine the morphology of their terminals in the dorsal horn. At the light microscopic level, terminal arborizations were observed in laminae II-VI of the dorsal horn, extending up to 7 mm rostrocaudally in and near the seventh lumbar segment. Bouton-like swellings, predominantly (67%) of the en passant type, were distributed in two discrete clusters, one concentrated rostrally in Rexed's laminae III-IV, and the other concentrated caudally in lamina V. At the electron microscopic level, a combination of morphometric and serial reconstructive analyses with 3 fibers revealed the following. Boutons labelled with HRP invariably contained clear round vesicles, approximately 40 nm in diameter. Labelled bouton sections had longest dimensions of 1.84 +/- 0.63 micron. Their shapes varied from rounded to elongated forms with occasional scalloped appearances. A majority (73%) of the contacts associated with HRP-filled boutons were made with dendritic spines and shafts. Thick postsynaptic densities were usually associated with these synapses, although thinner densities were also observed. 24% of the contacts made by labelled boutons were synapse-like contacts with unlabelled vesicle-containing structures. The vesicles in the unlabelled structures were usually pleomorphic, but sometimes round. These contacts were identified as 'synapse-like' because labelling obscured possible landmarks necessary for definitive identification of synapses. However, in most of these contacts, there was an accumulation of vesicles near the cleft on the unlabelled side, suggesting that the labelled boutons were postsynaptic. Only 3% of the contacts made by labelled boutons

  18. 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.

  19. Cord-Blood Banking

    Science.gov (United States)

    ... to Be Smart About Social Media Cord-Blood Banking KidsHealth > For Parents > Cord-Blood Banking Print A ... for you and your family. About Cord-Blood Banking Cord-blood banking basically means collecting and storing ...

  20. 不同功率的低强度激光对神经病理性疼痛大鼠痛阈及脊髓背角5-HT、GABA表达的影响%Effect of low-level laser therapy on the pain and the expression of 5-HT and GABA in spinal cord dorsal horn in rats with neuropathic pain

    Institute of Scientific and Technical Information of China (English)

    秦茵; 钱兴皋; 刘奥; 吴基伟; 张长龙; 胡志宏; 李平

    2016-01-01

    目的 探讨低强度激光对神经病理性疼痛大鼠的镇痛作用、机制及最佳照射参数.方法 56只雄性SD大鼠随机分为假手术组,模型组,10 nw和30 nw激光照射组四个组,模型组以及激光照射组制成坐骨神经缩窄性损伤模型.每组14只,分别于术前1d、术后1d、激光照射后3d、12 d测定大鼠热水甩尾潜伏期(tail flick latency,TEL).于激光照射后3d、12 d各取7只采用免疫组化方法检测大鼠脊髓背角GABA、5-HT的表达.结果 与假手术组比较,模型组以及激光照射组术后1d大鼠痛阈降低(P<0.05);与模型组比较,术后12 d,激光照射组TFL明显延长(P<0.05),脊髓背角5-HT、GABA的表达显著增加(P<0.05),30 nw优于10 nw(P<0.05).结论 低强度激光能提高神经病理性疼痛大鼠的痛阈,激光治疗强度30nw优于10nw,其治疗机制可能与促进神经递质5-HT、GABA的表达有关.

  1. 右美托咪啶对神经痛大鼠脊髓背角pERK、pCREB表达的影响%Effection of Dexmedet Tomidine on Expression of pERK, pCREB in Spinal Cord Dorsal Horn in a Rat Model of Chronic Neuropathic Pain

    Institute of Scientific and Technical Information of China (English)

    高毅; 孙丽; 王哲; 李琳坤; 张萌

    2015-01-01

    目的:评价右美托咪啶对神经病理性痛大鼠脊髓背角神经元磷酸化胞外反应激酶(phosphoryltion of extracellular regulated protein kinases,pERK)、磷酸化cAMP反应元件结合蛋白(phosphoryltion of Camp response element bound protein,pCREB)蛋白表达的影响.方法:健康成年雄性Wistar大鼠54只,6~8周龄,体重180~220 g,采用随机数字表法,将其分为3组(n=18):假手术组(S组)、慢性神经病理性痛组(C组)和右美托咪啶组(D组).S组仅分离坐骨神经但不结扎,C组和D组采用结扎坐骨神经的方法制备大鼠坐骨神经慢性压迫性损伤(chronic constriction injury,CCI)的神经病理性痛模型,D组于术后即刻开始至处死前1d腹腔注射右美托咪啶50 μg/kg,1次/d,S组和C组注射等容量生理盐水.于术前1d、术后3、7、14d时以缩足阈值(paw withdrawal threshold,PWT)测定大鼠机械痛阈和辐射热的缩足潜伏期(paw withdrawllatency,PWL)测定大鼠的热痛阈,并于术后测定痛阈后灌注处死大鼠,取L4-6脊髓组织,采用免疫组织化学法检测脊髓背角神经元pERK、pCREB的表达水平.结果:与S组比较,C组和D组术后3、7、14d时MWT降低,TWL缩短,脊髓背角pERK、pCREB表达上调(P<0.05);与C组比较,D组术后3、7、14d时MWT升高,TWL延长,脊髓背角pERK、pCREB表达下调(P<0.05).与术前1d比较,C组和D组术后3、7、14d时MWT降低,TWL缩短;与术后3d时比较,C组和D组7、14d时MWT降低,TWL缩短,脊髓背角pERK、pCREB表达上调(P<0.05).结论:右美托咪啶可减轻大鼠慢性神经病理性痛,抑制pERK、pCREB的表达可能是其作用机制之一.

  2. Increased Expression of P2X7 Receptors Evoked by ATP in Cultured Spinal Cord Dorsal Horn Astrocytes%ATP刺激培养脊髓背角星形胶质细胞P2X7受体表达上调

    Institute of Scientific and Technical Information of China (English)

    曾俊伟; 刘晓红; 阮怀珍

    2008-01-01

    目的 观察体外培养的脊髓背角星形胶质细胞P2X1-7 受体表达,以及不同浓度三磷酸腺苷(adenosine triphosphate,ATP)对P2X1-7 受体及胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)表达的影响.方法 培养并纯化脊髓背角星形胶质细胞,采用免疫组织化学染色观察P2受体表达.随后在无血清培养条件下,加入不同浓度ATP(100μM,500μM,1mM,2mM)作用24h 后,观察脊髓背角星形胶质细胞P2X1-7 受体表达及GFAP表达的变化.对照组加入0.01M PBS处理24h.IPP图象分析软件得到P2X受体以及GFAP阳性细胞平均光密度.结果 体外培养的大鼠脊髓背角星形胶质细胞表达P2X1,P2X2,P2X4, P2X5,P2X6 和P2X7 受体; 在ATP(100μM,500μM,1mM,2mM)作用下,P2X1,P2X2,P2X4, P2X5,P2X6受体表达未见明显变化,而P2X7受体和 GFAP表达逐渐上调,并具量效关系.结论 体外培养的大鼠脊髓背角星形胶质细胞表达P2X1,P2X2,P2X4, P2X5,P2X6和P2X7受体,而ATP可以诱发星形胶质细胞GFAP及P2X7受体表达上调,这一结果提示,其中P2X7可能参与脊髓背角星形胶质细胞活性的调节.

  3. New understanding of dorsal dysraphism with lipoma (lipomyeloschisis): radiologic evaluation and surgical correction

    Energy Technology Data Exchange (ETDEWEB)

    Naidich, T.P. (Northwestern Univ., Chicago, IL); McLone, D.G.; Mutluer, S.

    1983-06-01

    The spinal anomaly designated dorsal dysraphism with lipoma (lipomyeloschisis) consists of skin-covered, focal spina bifida; focal partial clefting of the dorsal half of the spinal cord; continuity of the dorsal cleft with the central canal of the cord above (and occasionally below) the cleft; deficiency of the dura underlying the spina bifida; deep extension of subcutaneous lipoma through the spina bifida and the dural deficiency to insert directly into the cleft on the dorsal half of the cord; variable cephalic extension of lipoma into the contiguous central canal of the cord; and variable ballooning of the subarachnoid space to form an associated meningocele. The variable individual expressions of the anomaly are best understood by reference to their archetypal concept. Careful analysis of radiographic and surgical findings in human lipomyeloschisis and correlation with an animal model of lipomyeloschisis indicate that plain spine radiographs and high-resolution metrizamide computed tomographic myelography successfully delineate the precise anatomic derangements associated with lipomyeloschisis and provide the proper basis for planning surgical therapy of this condition.

  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. RELATIONSHIP BETWEEN ANALGESIA AND EXTRACELLULAR MORPHINE IN BRAIN AND SPINAL-CORD IN AWAKE RATS

    NARCIS (Netherlands)

    MATES, FF; ROLLEMA, H; TAIWO, YO; LEVINE, JD; BASBAUM, AI

    1995-01-01

    Extracellular concentrations of morphine from the dorsal spinal cord, the periaqueductal gray (FAG) including the dorsal raphe, and the lateral hypothalamus were measured by microdialysis in awake rats after intraperitoneal (i.p.) administration of 2.5, 5.0 and 10 mg/kg morphine. Morphine concentrat

  6. 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.

  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. Planck LFI flight model feed horns

    CERN Document Server

    Villa, F; Pecora, M; Figini, L; Nesti, R; Simonetto, A; Sozzi, C; Sandri, M; Battaglia, P; Guzzi, P; Bersanelli, M; Butler, R C; Mandolesi, N; 10.1088/1748-0221/4/12/T12004

    2010-01-01

    this paper is part of the Prelaunch status LFI papers published on JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jinst The Low Frequency Instrument is optically interfaced with the ESA Planck telescope through 11 corrugated feed horns each connected to the Radiometer Chain Assembly (RCA). This paper describes the design, the manufacturing and the testing of the flight model feed horns. They have been designed to optimize the LFI optical interfaces taking into account the tight mechanical requirements imposed by the Planck focal plane layout. All the eleven units have been successfully tested and integrated with the Ortho Mode transducers.

  9. Substance P mRNA expression in the rat spinal cord following selective brachial plexus injury

    Institute of Scientific and Technical Information of China (English)

    Na Liu; Longju Chen; Feng Li; Wutian Wu

    2008-01-01

    BACKGROUND: The neuropeptide, substance P, has various bioactivities and is widely distributed in the central nervous system. Substance P participates in neural transmission in the spinal cord and plays an important role in regeneration and repair of nerve injury.OBJECTIVE: To investigate substance P mRNA expression in the anterior horn of the spinal cord following brachial plexus injury.DESIGN, TIME AND SETTING: A molecular cell biology randomized controlled study was performed at the Department of Anatomy, Zhongshan Medical College, Sun Yat-sen University and the DaAn Gene Laboratory in May 2005.MATERIALS: A total of 29 adult male Sprague Dawley rats were randomly assigned to a control group (n=5) and an injury group (n = 24).METHODS: The injury group was divided into three subgroups. In subgroup A, the right seventh cervical vertebra (C7) anterior root was avulsed, and the residual nerve root at the distal end was removed. In subgroup B, the right C7 anterior root was avulsed, and the right C5 first thoracic vertebrae (TO posterior root was incised. Thus afferent pathways of the posterior root that connected with the anterior horn motor neurons were blocked. In subgroup C, the right C7 anterior root was avulsed, and a right C5-6 hemisection was performed. Thus the descending fiber pathways of the cortex that connected with anterior horn motor neurons were blocked. In the control group, the C5-T1 vertebral plate was opened, and then the skin was sutured.MAIN OUTCOME MEASURE: Substance P mRNA expression in the anterior horn of the spinal cord was quantified using fluorescent quantitative reverse transcription-polymerase chain reaction.RESULTS: Substance P mRNA expression was low in the anterior horn of the rat spinal cord in the control group. Substance P mRNA expression in the anterior horn of the spinal cord was upregulated and was significantly higher in the injury group compared with the control group (P < 0.01 ). Substance P mRNA expression was highest in

  10. Presumptive keratoglobus in a great horned owl (Bubo virginianus).

    Science.gov (United States)

    Lau, Rachael K; Moresco, Anneke; Woods, Sarah J; Reilly, Christopher M; Hawkins, Michelle G; Murphy, Christopher J; Hollingsworth, Steven R; Hacker, Dennis; Freeman, Kate S

    2016-07-31

    A juvenile to young adult, male, great horned owl (Bubo virginianus,GHOW) was presented to the wildlife rehabilitation hospital at Lindsay Wildlife Museum (WRHLWM) due to trauma to the right patagium from barbed wire entanglement. On presentation, both corneas were irregular, dry, and no movement of the third eyelid was noted. A severe corneal enlargement/globoid appearance was the predominant ophthalmic feature. The fundus was normal in both eyes (OU). Over the course of several days, both corneas developed edema combined with further dessication at the ocular surface associated with diffuse dorsal fluorescein stain uptake. Repeated ophthalmic examinations found normal intraocular pressures and an inability to move the third eyelid over the enlarged corneas. The bird was deemed nonreleasable due to severe wing damage and poor prognosis associated with eye abnormalities and was humanely euthanized. Postmortem CT, enucleation, and histopathology were performed to evaluate the ocular anatomical abnormality and confirm the suspected diagnosis of keratoglobus. This GHOW represents the first reported case of presumptive keratoglobus in a raptor.

  11. Inhibitory Interneurons That Express GFP in the PrP-GFP Mouse Spinal Cord Are Morphologically Heterogeneous, Innervated by Several Classes of Primary Afferent and Include Lamina I Projection Neurons among Their Postsynaptic Targets.

    Science.gov (United States)

    Ganley, Robert P; Iwagaki, Noboru; del Rio, Patricia; Baseer, Najma; Dickie, Allen C; Boyle, Kieran A; Polgár, Erika; Watanabe, Masahiko; Abraira, Victoria E; Zimmerman, Amanda; Riddell, John S; Todd, Andrew J

    2015-05-13

    The superficial dorsal horn of the spinal cord contains numerous inhibitory interneurons, which regulate the transmission of information perceived as touch, pain, or itch. Despite the importance of these cells, our understanding of their roles in the neuronal circuitry is limited by the difficulty in identifying functional populations. One group that has been identified and characterized consists of cells in the mouse that express green fluorescent protein (GFP) under control of the prion protein (PrP) promoter. Previous reports suggested that PrP-GFP cells belonged to a single morphological class (central cells), received inputs exclusively from unmyelinated primary afferents, and had axons that remained in lamina II. However, we recently reported that the PrP-GFP cells expressed neurona