101
|
Yang CJ, Li Q, Wu GC, Wang YQ, Mao-Ying QL. A practical model of osteomyelitis-induced bone pain by intra-tibial injection of Staphylococcus aureus in rats. Neurosci Lett 2012; 513:198-203. [DOI: 10.1016/j.neulet.2012.02.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 02/10/2012] [Accepted: 02/12/2012] [Indexed: 11/26/2022]
|
102
|
High-mobility group box 1 contributes to mechanical allodynia and spinal astrocytic activation in a mouse model of type 2 diabetes. Brain Res Bull 2012; 88:332-7. [PMID: 22459482 DOI: 10.1016/j.brainresbull.2012.03.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 02/13/2012] [Accepted: 03/11/2012] [Indexed: 12/20/2022]
Abstract
Chronic pain is one of the most common complications of diabetes. However, current treatments for diabetic pain are usually unrealistic because the underlying mechanisms are far from being clear. Immerging studies have implicated immune factors as key players in the diabetic pain. High-mobility group box 1 (HMGB1) is an important mediator of inflammatory response, but its role in diabetic pain is unclear. In the present study, we observed that db/db mice (a model of type 2 diabetes) developed persistent mechanical allodynia from postnatal 2 months. Western blot showed that in postnatal 2-5 months, HMGB1 was significantly higher than that of the heterozygous littermates (db/+) mice. Intrathecal injection of a HMGB1 neutralizing antibody (anti-HMGB1) inhibited mechanical allodynia. Immunostaining data showed that compared with db/+ and C57 mice (postnatal 4 months), glial fibrillary acidic protein (GFAP) staining was significantly increased in the spinal cord of db/db mice. Anti-HMGB1 could effectively decrease GFAP expression. Real-time PCR showed that in postnatal 4 months, db/db mice induced significant increases of TNF-alpha, IL-1β, IL-6 and monocyte chemoattractant protein-1 (MCP-1) in the spinal dorsal horn, while anti-HMGB1 (50 μg) effectively inhibited the up-regulation of these inflammatory mediators. Our results indicate that HMGB1 is significantly up-regulated in the spinal cord of type 2 diabetes, and inhibiting HMGB1 may provide a novel treatment for diabetic pain.
Collapse
|
103
|
Women with endometriosis are more likely to suffer from migraines: a population-based study. PLoS One 2012; 7:e33941. [PMID: 22442736 PMCID: PMC3307779 DOI: 10.1371/journal.pone.0033941] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 02/21/2012] [Indexed: 11/19/2022] Open
Abstract
Previous research suggests that a co-morbid relationship exists between migraine and endometriosis; however, results have been inconsistent. In addition, female hormones, which are important in the pathogenesis and management of endometriosis, have been reported to precipitate migraine attacks and may confound the results. The aim of this population-based cohort study was to explore the relationship between migraine and endometriosis in women of reproductive age (18-51 years). Data were derived from the National Health Insurance Research Database of Taiwan, which contains outpatient and inpatient records from 2000 to 2007. Our study cohort included 20,220 endometriosis patients and 263,767 controls without endometriosis. We analyzed the prevalence of migraine in these women as recorded during the eight years of the database. Our results found that patients with endometriosis were more likely to suffer migraine headaches compared to controls (odds ratio [OR], 1.70; 95% confidence interval [CI] [1.59, 1.82]; p<0.001). In addition, the co-morbid association between migraine and endometriosis remained significant after the data were controlled for age and frequently utilized hormone therapies (OR, 1.37; 95% CI, [1.27, 1.47]; p<0.001). The results of this cohort study support the existence of a co-morbid relationship between migraine and endometriosis, even after adjusting for the possible effects of female hormone therapies on migraine attacks.
Collapse
|
104
|
Gabayl E, Wolfl G, Shavitl Y, Yirmiyal R, Tall M. Chronic blockade of interleukin-1 (IL-1) prevents and attenuates neuropathic pain behavior and spontaneous ectopic neuronal activity following nerve injury. Eur J Pain 2012; 15:242-8. [DOI: 10.1016/j.ejpain.2010.07.012] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 06/15/2010] [Accepted: 07/30/2010] [Indexed: 01/13/2023]
|
105
|
Takahashil K, Watanabel M, Suekawal Y, Itol G, Inubushil T, Hirosel N, Murasakil K, Hiyamal S, Uchidal T, Tannel K. IL-1beta in the trigeminal subnucleus caudalis contributes to extra-territorial allodynia/hyperalgesia following a trigeminal nerve injury. Eur J Pain 2012; 15:467.e1-14. [DOI: 10.1016/j.ejpain.2010.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 10/08/2010] [Accepted: 10/15/2010] [Indexed: 11/26/2022]
|
106
|
Wei XH, Yang T, Wu Q, Xin WJ, Wu JL, Wang YQ, Zang Y, Wang J, Li YY, Liu XG. Peri-sciatic administration of recombinant rat IL-1β induces mechanical allodynia by activation of src-family kinases in spinal microglia in rats. Exp Neurol 2012; 234:389-97. [PMID: 22265659 DOI: 10.1016/j.expneurol.2012.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 12/24/2011] [Accepted: 01/04/2012] [Indexed: 12/01/2022]
Abstract
Previous studies have shown that Interleukin-1 beta (IL-1β) is implicated in the modulation of pain sensitivity. In the present study, we found that a single peri-sciatic administration of rat recombinant IL-1β (rrIL-1β) at doses of 20 and 200 pg (100, 1000 ng/l, in 200 μl volume) induced mechanical allodynia in bilateral hindpaws in rats, lasting for about 50 days. No axonal or Schwann cell damage at the drug administration site was found following 1000 ng/l rrIL-1β administration. The results of immunofluorescence showed that microglial cells in bilateral spinal dorsal horn were activated after peri-sciatic administration of rrIL-1β (1000 ng/l). The immunoreactivity (IR) of Iba1 (a marker for microglia) and phosphorylated src-family kinases (p-SFKs) increased significantly in the ipsilateral and contralateral lumbar spinal dorsal horn on day 1 and day 3 after rrIL-1β administration, respectively. Double immunofluorescence staining revealed that the increased p-SFKs-IR was almost restricted within the microglia. Intrathecal delivery of minocycline (100 μg in 10 μl volume), a selective inhibitor of microglia, started 30 min before rrIL-1β administration and once daily thereafter for 7 days, blocked mechanical allodynia induced by rrIL-1β completely and inhibited the upregulation of p-SFKs. Intrathecal delivery of SFKs inhibitor PP2 (12 μg in 10 μl volume) also blocked mechanical allodynia induced by rrIL-1β completely. These data suggest that activation of SFKs in spinal microglia mediates mechanical allodynia induced by peri-sciatic administration of rrIL-1β.
Collapse
Affiliation(s)
- Xu-Hong Wei
- Pain Research Center and Department of Physiology, Zhongshan Medical School of Sun Yat-Sen University, 74 Zhongshan Rd. 2, Guangdong, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
107
|
|
108
|
Richards N, Batty T, Dilley A. CCL2 has similar excitatory effects to TNF-α in a subgroup of inflamed C-fiber axons. J Neurophysiol 2011; 106:2838-48. [PMID: 21865436 PMCID: PMC3234089 DOI: 10.1152/jn.00183.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Peripheral nerve inflammation can cause neuronal excitability changes that have been implicated in the pathogenesis of chronic pain. Although the neuroimmune interactions that lead to such physiological changes are unclear, in vitro studies suggest that the chemokine CCL2 may be involved. This in vivo study examines the effects of CCL2 on untreated and inflamed neurons and compares its effects with those of TNF-α. Extracellular recordings were performed in the anesthetized rat on isolated neurons with C-fiber axons. On untreated neurons, CCL2, as well as TNF-α, had negligible effects. Following neuritis, both cytokines transiently caused the firing of action potentials in 27–30% of neurons, which were either silent or had background (ongoing) activity. The neurons with ongoing activity, which responded to either cytokine, had significantly slower baseline firing rates {median = 3.0 spikes/min [interquartile range (IQR) 3.0]} compared with the nonresponders [median = 24.4 spikes/min (IQR 24.6); P < 0.001]. In an additional group, 26–27% of neurons, which were sensitized due to repeated noxious mechanical stimulation of the periphery, also responded to the effects of both cytokines. Neither cytokine caused axons to become mechanically sensitive. Immunohistochemistry confirmed that the cognate CCL2 receptor, CCR2, is mainly expressed on glia and is therefore not likely to be an axonal target for CCL2 following inflammation. In contrast, the cognate TNF-α receptor (TNFR), TNFR1, was present on untreated and inflamed neurons. In summary, CCL2 can excite inflamed C-fiber neurons with similar effects to TNF-α, although the underlying mechanisms may be different. The modulatory effects of both cytokines are limited to a subgroup of neurons, which may be subtly inflamed.
Collapse
Affiliation(s)
- Natalie Richards
- Division of Clinical and Laboratory Investigation, Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton, UK
| | | | | |
Collapse
|
109
|
Wieseler J, Ellis AL, McFadden A, Brown K, Starnes C, Maier SF, Watkins LR, Falci S. Below level central pain induced by discrete dorsal spinal cord injury. J Neurotrauma 2011; 27:1697-707. [PMID: 20649467 DOI: 10.1089/neu.2010.1311] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Central neuropathic pain occurs with multiple sclerosis, stroke, and spinal cord injury (SCI). Models of SCI are commonly used to study central neuropathic pain and are excellent at modeling gross physiological changes. Our goal was to develop a rat model of central neuropathic pain by traumatizing a discrete region of the dorsal spinal cord, thereby avoiding issues including paralysis, urinary tract infection, and autotomy. To this end, dorsal root avulsion was pursued. The model was developed by first determining the number of avulsed dorsal roots sufficient to induce below-level hindpaw mechanical allodynia. This was optimally achieved by unilateral T13 and L1 avulsion, which resulted in tissue damage confined to Lissauer's tract, dorsal horn, and dorsal columns, at the site of avulsion, with no gross physical changes at other spinal levels. Behavior following avulsion was compared to that following rhizotomy of the T13 and L1 dorsal roots, a commonly used model of neuropathic pain. Avulsion induced below-level allodynia that was more robust and enduring than that seen after rhizotomy. This, plus the lack of direct spinal cord damage associated with rhizotomy, suggests that avulsion is not synonymous with rhizotomy, and that avulsion (but not rhizotomy) is a model of central neuropathic pain. The new model described here is the first to use discrete dorsal horn damage by dorsal root avulsion to create below-level bilateral central neuropathic pain.
Collapse
Affiliation(s)
- Julie Wieseler
- Department of Psychology and Neuroscience and the Center for Neurosciences, Campus Box 345, University of Colorado at Boulder, Boulder, Colorado 80309-0345, USA.
| | | | | | | | | | | | | | | |
Collapse
|
110
|
Hains LE, Loram LC, Weiseler JL, Frank MG, Bloss EB, Sholar P, Taylor FR, Harrison JA, Martin TJ, Eisenach JC, Maier SF, Watkins LR. Pain intensity and duration can be enhanced by prior challenge: initial evidence suggestive of a role of microglial priming. THE JOURNAL OF PAIN 2011; 11:1004-14. [PMID: 20434956 DOI: 10.1016/j.jpain.2010.01.271] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2009] [Revised: 12/12/2009] [Accepted: 01/25/2010] [Indexed: 01/09/2023]
Abstract
UNLABELLED Activation of spinal microglia and consequent release of proinflammatory mediators facilitate pain. Under certain conditions, responses of activated microglia can become enhanced. Enhanced microglial production of proinflammatory products may result from priming (sensitization), similar to macrophage priming. We hypothesized that if spinal microglia were primed by an initial inflammatory challenge, subsequent challenges may create enhanced pain. Here, we used a "two-hit" paradigm using 2 successive challenges, which affect overlapping populations of spinal microglia, presented 2 weeks apart. Mechanical allodynia and/or activation of spinal glia were assessed. Initially, laparotomy preceded systemic lipopolysaccharide (LPS). Prior laparotomy caused prolonged microglial (not astrocyte) activation plus enhanced LPS-induced allodynia. In this "two-hit" paradigm, minocycline, a microglial activation inhibitor, significantly reduced later exaggerated pain induced by prior surgery when minocycline was administered intrathecally for 5 days starting either at the time of surgery or 5 days before LPS administration. To test generality of the priming effect, subcutaneous formalin preceded intrathecal HIV-1 gp120, which activates spinal microglia and causes robust allodynia. Prior formalin enhanced intrathecal gp120-induced allodynia, suggesting that microglial priming is not limited to laparotomy and again supporting a spinal site of action. Therefore, spinal microglial priming may increase vulnerability to pain enhancement. PERSPECTIVE Spinal microglia may become "primed" (sensitized) following their activation by disparate forms of peripheral trauma/inflammation. As a result, such primed microglia may overrespond to subsequent challenges, thereby enhancing pain intensity and duration.
Collapse
Affiliation(s)
- Leah E Hains
- Department of Psychology and Neuroscience, and the Center for Neuroscience, University of Colorado at Boulder, Boulder, Colorado 80309-0345, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
111
|
Benison AM, Chumachenko S, Harrison JA, Maier SF, Falci SP, Watkins LR, Barth DS. Caudal granular insular cortex is sufficient and necessary for the long-term maintenance of allodynic behavior in the rat attributable to mononeuropathy. J Neurosci 2011; 31:6317-28. [PMID: 21525272 PMCID: PMC3089761 DOI: 10.1523/jneurosci.0076-11.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 03/02/2011] [Accepted: 03/09/2011] [Indexed: 12/22/2022] Open
Abstract
Mechanical allodynia, the perception of innocuous tactile stimulation as painful, is a severe symptom of chronic pain often produced by damage to peripheral nerves. Allodynia affects millions of people and remains highly resistant to classic analgesics and therapies. Neural mechanisms for the development and maintenance of allodynia have been investigated in the spinal cord, brainstem, thalamus, and forebrain, but manipulations of these regions rarely produce lasting effects. We found that long-term alleviation of allodynic manifestations is produced by discreetly lesioning a newly discovered somatosensory representation in caudal granular insular cortex (CGIC) in the rat, either before or after a chronic constriction injury of the sciatic nerve. However, CGIC lesions alone have no effect on normal mechanical stimulus thresholds. In addition, using electrophysiological techniques, we reveal a corticospinal loop that could be the anatomical source of the influence of CGIC on allodynia.
Collapse
Affiliation(s)
- Alexander M. Benison
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309-0345
| | - Serhiy Chumachenko
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309-0345
| | - Jacqueline A. Harrison
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309-0345
| | - Steven F. Maier
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309-0345
| | - Scott P. Falci
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309-0345
| | - Linda R. Watkins
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309-0345
| | - Daniel S. Barth
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado 80309-0345
| |
Collapse
|
112
|
|
113
|
Prolonged gingival cold allodynia: a novel finding in patients with atypical odontalgia. ACTA ACUST UNITED AC 2011; 111:312-9. [DOI: 10.1016/j.tripleo.2010.10.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 10/03/2010] [Accepted: 10/08/2010] [Indexed: 11/22/2022]
|
114
|
Grace PM, Hutchinson MR, Bishop A, Somogyi AA, Mayrhofer G, Rolan PE. Adoptive transfer of peripheral immune cells potentiates allodynia in a graded chronic constriction injury model of neuropathic pain. Brain Behav Immun 2011; 25:503-13. [PMID: 21134441 DOI: 10.1016/j.bbi.2010.11.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 11/30/2010] [Accepted: 11/30/2010] [Indexed: 10/18/2022] Open
Abstract
Recent evidence demonstrates that peripheral immune cells contribute to the nociceptive hypersensitivity associated with neuropathic pain by infiltrating the central nervous system (CNS). We have recently developed a rat model of graded chronic constriction injury (CCI) by varying the exposure of the sciatic nerve and control non-nerve tissue to surgical placement of chromic gut. We demonstrate that splenocytes can contribute significantly to CCI-induced allodynia, as adoptive transfer of these cells from high pain donors to low pain recipients potentiates allodynia (P<0.001). The phenomenon was replicated with peripheral blood mononuclear cells (P<0.001). Adoptive transfer of allodynia was not achieved in sham recipients, indicating that peripheral immune cells are only capable of potentiating existing allodynia, rather than establishing allodynia. As adoptively transferred cells were found by flow cytometry to migrate to the spleen (P<0.05) and potentiation of allodynia was prevented in splenectomised low pain recipients, adoptive transfer of high pain splenocytes may induce the migration of host-derived immune cells from the spleen to the CNS as observed by flow cytometry (P<0.05). Importantly, intrathecal transfer of CD45(+) cells prepared from spinal cords of high pain donors into low pain recipients led to potentiated allodynia (P<0.001), confirming that infiltrating immune cells are not passive bystanders, but actively contribute to nociceptive hypersensitivity in the lumbar spinal cord.
Collapse
Affiliation(s)
- Peter M Grace
- Discipline of Pharmacology, School of Medical Sciences, University of Adelaide, Adelaide 5005, Australia.
| | | | | | | | | | | |
Collapse
|
115
|
GABAergic pathway in a rat model of chronic neuropathic pain: Modulation after intrathecal transplantation of a human neuronal cell line. Neurosci Res 2011; 69:111-20. [DOI: 10.1016/j.neures.2010.10.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 09/09/2010] [Accepted: 10/14/2010] [Indexed: 12/30/2022]
|
116
|
|
117
|
Katz J, Melzack R. A Conceptual Framework for Understanding Pain in the Human. Pain Manag 2011. [DOI: 10.1016/b978-1-4377-0721-2.00001-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
118
|
Öztürk N, Erin N, Tüzüner S. Changes in Tissue Substance P Levels in Patients With Carpal Tunnel Syndrome. Neurosurgery 2010; 67:1655-60; discussion 1660-1. [DOI: 10.1227/neu.0b013e3181fa7032] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Abstract
BACKGROUND:
Although carpal tunnel syndrome (CTS) is the most common entrapment neuropathy in adults, its etiology is not completely known. Chronic inflammation, fibrosis of the transverse carpal ligament (TCL), and altered sensory response contribute to the symptoms.
OBJECTIVE:
Because substance P (SP) is known to be involved in neuropathic pain, chronic inflammation, and fibrosis, the present study evaluated changes in SP levels in patients with CTS.
METHODS:
TCL, median nerve adventitia, and synovial connective tissue of the middle flexor digitorum superficialis tendon samples from patients (n = 42) with CTS and healthy control subjects (n = 13) who were operated on for hand wounds were obtained at surgery. A group of these patients with CTS (n = 9) had received meloxicam treatment for 10 days before surgery. A 2-step acetic acid extraction was used to determine changes in SP levels in free nerve endings (neuronal) and in nonneuronal cells.
RESULTS:
Changes in SP levels were observed in both neuronal and nonneuronal tissues. SP levels increased in extracts of the TCL and synovial connective tissue of the middle flexor digitorum superficialis tendon but not in the median nerve adventitia of patients with CTS. Meloxicam pretreatment increased SP levels in nonneuronal components of the TCL.
CONCLUSION:
These findings suggest that SP contributes to the pain and inflammation associated with CTS. Further studies are required to evaluate the therapeutic potentials of SP receptor (NK1R) antagonists in CTS.
Collapse
Affiliation(s)
- Niyazi Öztürk
- Department of Orthopedics and Traumatology, School of Medicine, Akdeniz University, Antalya, Turkey
| | - Nuray Erin
- Department of Medical Pharmacology, School of Medicine, Akdeniz University, Antalya, Turkey
| | - Serdar Tüzüner
- Department of Orthopedics and Traumatology, School of Medicine, Akdeniz University, Antalya, Turkey
| |
Collapse
|
119
|
Specific mechanical pain hypersensitivity over peripheral nerve trunks in women with either unilateral epicondylalgia or carpal tunnel syndrome. J Orthop Sports Phys Ther 2010; 40:751-60. [PMID: 21041964 DOI: 10.2519/jospt.2010.3331] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
STUDY DESIGN Case-control study with blinded examiner. OBJECTIVE To investigate if pressure pain sensitivity is related to specific nerve trunks in the upper extremity of patients with either unilateral lateral epicondylalgia (LE) or carpal tunnel syndrome (CTS). BACKGROUND In the clinical setting, patients with LE tend to exhibit radial nerve trunk tenderness, whereas patients with CTS exhibit median nerve tenderness. No studies have investigated if specific nerve pressure pain hypersensitivity exists in patients with either LE or CTS. METHODS Sixteen women with unilateral LE (mean±SD age, 43±7 years), 17 women with unilateral CTS (43±6 years), and 17 healthy women (43±6 years) were included in this study. Pressure pain thresholds (PPT) were bilaterally assessed over the median, ulnar, and radial nerve trunks, as well as over the C5-6 zygapophyseal joints, by an examiner blinded to the subjectsí condition. A mixed-model analysis of variance was used to evaluate differences in PPT among groups (LE, CTS, or controls) and between sides (affected/nonaffected or dominant/nondominant). RESULTS The individuals in both the LE and CTS groups demonstrated lower PPT bilaterally over the median (group, P<.001; side, P=.437), radial (group, P<.001; side, P=.556), and ulnar (group, P<.001; side, P=.938) nerve trunks as compared to controls. Additionally, radial (P<.001) and ulnar (P=.005) nerves were more sensitive bilaterally in patients with LE than in patients with CTS. The median nerve was more sensitive bilaterally in patients with CTS than patients with LE (P=.002). Lower PPT over the cervical spine (group, P<.001; side, P=.233) were found bilaterally in both the LE and CTS groups. Further, patients with CTS exhibited lower cervical PPT than patients with LE (P<.001). PPT was negatively correlated with both pain intensity and duration of symptoms in both the LE and CTS groups (P<.001). CONCLUSIONS Bilateral mechanical nerve pain hypersensitivity is related to specific and particular nerve trunks in women with either unilateral LE or CTS. Our results suggest the presence of central and peripheral sensitization mechanisms in individuals with either LE or CTS.
Collapse
|
120
|
Elliott M, Barr A, Clark B, Wade C, Barbe M. Performance of a repetitive task by aged rats leads to median neuropathy and spinal cord inflammation with associated sensorimotor declines. Neuroscience 2010; 170:929-41. [DOI: 10.1016/j.neuroscience.2010.07.041] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 07/21/2010] [Accepted: 07/21/2010] [Indexed: 12/30/2022]
|
121
|
Grace PM, Hutchinson MR, Manavis J, Somogyi AA, Rolan PE. A novel animal model of graded neuropathic pain: utility to investigate mechanisms of population heterogeneity. J Neurosci Methods 2010; 193:47-53. [PMID: 20817038 DOI: 10.1016/j.jneumeth.2010.08.025] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 08/20/2010] [Accepted: 08/24/2010] [Indexed: 01/01/2023]
Abstract
The mechanisms underlying neuropathic pain are not well understood, resulting in unsatisfactory treatment outcomes for many patients. Animal models underpin much of the current understanding of pain mechanisms due to their perceived ability to mimic pain hypersensitivities; however, are limited by their binomial approach (pain vs. control), which does not reflect the clinical heterogeneity in nociceptive hypersensitivity. We modified the chronic constriction injury model by varying the number of sciatic nerve chromic gut sutures. Each Sprague Dawley rat received 4 pieces of chromic gut to control for the inflammatory challenge posed by the gut. Treatment groups were neuronal sutures (N), subcutaneous sutures (S) N0S0, N0S4, N1S3, N2S2 and N4S0. At postoperative (PO) day 29, there was a 'dose-response' relationship between the number of perineural sutures and von Frey threshold (N0S4<N1S3<N2S2<N4S0, P<0.05). This graded model was applied to investigate lumbar dorsal spinal cord glial activation marker expression. Microglial CD11b expression was positively correlated with graded allodynia in the ipsilateral dorsal horn (P<0.05, r(2)>0.9) and associated in the dorsolateral funiculus (DLF; P=0.10, r(2)>0.8) at PO day 14. Astrocyte GFAP expression was positively associated with graded allodynia in the ipsilateral dorsal horn (P=0.18, r(2)>0.6) and ipsilateral DLF (P<0.05, r(2)>0.9). DLF glial activation may represent a contributor to contralateral pain. Our novel graded model has a dynamic range, allowing sensitive detection of interactions and subtle influences on neuropathic pain processing.
Collapse
Affiliation(s)
- Peter M Grace
- Discipline of Pharmacology, School of Medical Sciences, University of Adelaide, Adelaide, Australia.
| | | | | | | | | |
Collapse
|
122
|
TNF-α contributes to up-regulation of Nav1.3 and Nav1.8 in DRG neurons following motor fiber injury. Pain 2010; 151:266-279. [PMID: 20638792 DOI: 10.1016/j.pain.2010.06.005] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 04/07/2010] [Accepted: 06/10/2010] [Indexed: 12/13/2022]
Abstract
A large body of evidence has demonstrated that the ectopic discharges of action potentials in primary afferents, resulted from the abnormal expression of voltage gated sodium channels (VGSCs) in dorsal root ganglion (DRG) neurons following peripheral nerve injury are important for the development of neuropathic pain. However, how nerve injury affects the expression of VGSCs is largely unknown. Here, we reported that selective injury of motor fibers by L5 ventral root transection (L5-VRT) up-regulated Nav1.3 and Nav1.8 at both mRNA and protein level and increased current densities of TTX-S and TTX-R channels in DRG neurons, suggesting that nerve injury may up-regulate functional VGSCs in sensory neurons indirectly. As the up-regulated Nav1.3 and Nav1.8 were highly co-localized with TNF-α, we tested the hypothesis that the increased TNF-α may lead to over-expression of the sodium channels. Indeed, we found that peri-sciatic administration of recombinant rat TNF-α (rrTNF) without any nerve injury, which produced lasting mechanical allodynia, also up-regulated Nav1.3 and Nav1.8 in DRG neurons in vivo and that rrTNF enhanced the expression of Nav1.3 and Nav1.8 in cultured adult rat DRG neurons in a dose-dependent manner. Furthermore, inhibition of TNF-α synthesis, which prevented neuropathic pain, strongly inhibited the up-regulation of Nav1.3 and Nav1.8. The up-regulation of the both channels following L5-VRT was significantly lower in TNF receptor 1 knockout mice than that in wild type mice. These data suggest that increased TNF-α may be responsible for up-regulation of Nav1.3 and Nav1.8 in uninjured DRG neurons following nerve injury.
Collapse
|
123
|
Zhu S, Li W, Ward MF, Sama AE, Wang H. High mobility group box 1 protein as a potential drug target for infection- and injury-elicited inflammation. ACTA ACUST UNITED AC 2010; 9:60-72. [PMID: 19906009 DOI: 10.2174/187152810791292872] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 11/03/2009] [Indexed: 12/11/2022]
Abstract
In response to infection or injury, a ubiquitous nucleosomal protein, HMGB1 is secreted actively by innate immune cells, and / or released passively by injured/damaged cells. Subsequently, extracellular HMGB1 alerts, recruits, and activates various innate immune cells to sustain a rigorous inflammatory response. A growing number of HMGB1 inhibitors ranging from neutralizing antibodies, endogenous hormones, to medicinal herb-derived small molecule HMGB1 inhibitors (such as nicotine, glycyrrhizin, tanshinones, and EGCG) are proven protective against lethal infection and ischemic injury. Here we review emerging evidence that support extracellular HMGB1 as a proinflammatory alarmin(g) danger signal, and discuss a wide array of HMGB1 inhibitors as potential therapeutic agents for sepsis and ischemic injury.
Collapse
Affiliation(s)
- Shu Zhu
- The Feinstein Institute for Medical Research, North Shore-LIJ Health System, Manhasset, NY 11030, USA
| | | | | | | | | |
Collapse
|
124
|
Shibasaki M, Sasaki M, Miura M, Mizukoshi K, Ueno H, Hashimoto S, Tanaka Y, Amaya F. Induction of high mobility group box-1 in dorsal root ganglion contributes to pain hypersensitivity after peripheral nerve injury. Pain 2010; 149:514-521. [DOI: 10.1016/j.pain.2010.03.023] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 01/21/2010] [Accepted: 03/17/2010] [Indexed: 01/01/2023]
|
125
|
Vallejo R, Tilley DM, Vogel L, Benyamin R. The Role of Glia and the Immune System in the Development and Maintenance of Neuropathic Pain. Pain Pract 2010; 10:167-84. [DOI: 10.1111/j.1533-2500.2010.00367.x] [Citation(s) in RCA: 227] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
126
|
Sorkin LS, Otto M, Baldwin WM, Vail E, Gillies SD, Handgretinger R, Barfield RC, Yu HM, Yu AL. Anti-GD(2) with an FC point mutation reduces complement fixation and decreases antibody-induced allodynia. Pain 2010; 149:135-142. [PMID: 20171010 DOI: 10.1016/j.pain.2010.01.024] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 01/27/2010] [Indexed: 10/19/2022]
Abstract
Monoclonal antibodies against GD(2) ganglioside, such as ch14.18, the human-mouse chimeric antibody, have been shown to be effective for the treatment of neuroblastoma. However, treatment is associated with generalized, relatively opiate-resistant pain. We investigated if a point mutation in ch14.18 antibody (hu14.18K332A) to limit complement-dependent cytotoxicity (CDC) would ameliorate the pain behavior, while preserving antibody-dependent cellular cytotoxicity (ADCC). In vitro, CDC and ADCC were measured using europium-TDA assay. In vivo, allodynia was evaluated by measuring thresholds to von Frey filaments applied to the hindpaws after injection of either ch14.18 or hu14.18K332 into wild type rats or rats with deficient complement factor 6. Other rats were pretreated with complement factor C5a receptor antagonist and tested following ch14.18 injection. The mutation reduces the antibody's ability to activate complement, while maintaining its ADCC capabilities. Injection of hu14.18K322 (1 or 3mg/kg) produced faster resolving allodynia than that engendered by ch14.18 (1mg/kg). Injection of ch14.18 (1mg/kg) into rats with C6 complement deficiency further reduced antibody-induced allodynia, while pre-treatment with complement factor C5a receptor antagonist completely abolished ch14.18-induced allodynia. These findings showed that mutant hu14.18 K322 elicited less allodynia than ch14.18 and that ch14.18-elicited allodynia is due to activation of the complement cascade: in part, to formation of membrane attack complex, but more importantly to release of complement factor C5a. Development of immunotherapeutic agents with decreased complement-dependent lysis while maintaining cellular cytotoxicity may offer treatment options with reduced adverse side effects, thereby allowing dose escalation of therapeutic antibodies.
Collapse
Affiliation(s)
- Linda S Sorkin
- Department of Anesthesiology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA Division of Immunology, Cleveland Clinic, Cleveland, Ohio 44195, USA Provenance Biopharmaceuticals Corp. Waltham, MA 01821, USA Department of Hematology/Oncology, Children's University Hospital, Tuebingen 72076, Germany Division of Pediatric Hematology and Oncology, Duke University, Durham, NC 27708, USA Department of Oncology, University of California San Diego, La Jolla, CA 92093, USA Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | | | | | | | | | | | | | | | | |
Collapse
|
127
|
Central sensitization in carpal tunnel syndrome with extraterritorial spread of sensory symptoms. Pain 2010; 148:227-236. [DOI: 10.1016/j.pain.2009.10.025] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Revised: 10/07/2009] [Accepted: 10/29/2009] [Indexed: 12/21/2022]
|
128
|
Chang YW, Tan A, Saab C, Waxman S. Unilateral Focal Burn Injury Is Followed by Long-Lasting Bilateral Allodynia and Neuronal Hyperexcitability in Spinal Cord Dorsal Horn. THE JOURNAL OF PAIN 2010; 11:119-30. [DOI: 10.1016/j.jpain.2009.06.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 06/15/2009] [Accepted: 06/17/2009] [Indexed: 12/30/2022]
|
129
|
Abstract
Sepsis refers to a systemic inflammatory response syndrome resulting from a microbial infection. The inflammatory response is partly mediated by innate immune cells (such as macrophages, monocytes, and neutrophils), which not only ingest and eliminate invading pathogens but also initiate an inflammatory response by producing early (e.g., TNF and IFN-gamma) and late (e.g., high-mobility group box [HMGB1]) proinflammatory cytokines. Here, we briefly review emerging evidence that support extracellular HMGB1 as a late mediator of experimental sepsis and discuss therapeutic potential of several HMGB1-inhibiting agents (including neutralizing antibodies and steroid-like tanshinones) in experimental sepsis.
Collapse
|
130
|
Upper limb neurodynamic test of the radial nerve: a study of responses in symptomatic and asymptomatic subjects. J Hand Ther 2009; 22:344-53; quiz 354. [PMID: 19560318 DOI: 10.1016/j.jht.2009.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2008] [Revised: 05/06/2009] [Accepted: 05/13/2009] [Indexed: 02/03/2023]
Abstract
STUDY DESIGN Clinical measurement. INTRODUCTION Nonspecific cervical pain is a common clinical presentation. The role of upper limb neurodynamic tests (ULNT), for evaluation and treatment intervention, is not well defined for this population. PURPOSE OF THE STUDY This study's purpose was to determine if the radial-biased (RB)-ULNT discriminates any response differences between symptomatic subjects with a positive (+) RB-ULNT (n=36), symptomatic subjects with a negative (-) RB-ULNT (n=24), and asymptomatic subjects (n=60). METHODS Sixty asymptomatic and 60 subjects presenting with nonspecific cervical and/or unilateral upper extremity pain were compared using the RB-ULNT. Symptomatic subjects were further divided in (+) and (-) RB-ULNT groups due to their response to the RB-ULNT. Within the symptomatic population, a positive response to the RB-ULNT was defined by the symptomatic subject reporting their sensations were increased with contralateral cervical lateral flexion and decreased with ipsilateral cervical lateral flexion. Sensation provocation and location were evaluated using the RB-ULNT in all the subjects during each stage of the testing. RESULTS Significant differences on stage of reproduction and type of sensations were identified between 1) the (+) RB-ULNT symptomatic subjects, 2) the (-) RB-ULNT symptomatic subjects, and 3) the asymptomatic subjects. The (+) RB-ULNT group showed significantly increased pain responses during the first stage of the RB-ULNT compared with the (-) RB-ULNT group and the asymptomatic subjects. The (+) RB-ULNT also showed significantly decreased glenohumeral abduction passive range of motion when compared with the asymptomatic group. CONCLUSION Clinically, the differences found between the groups in their response to the RB-ULNT suggest heightened mechanosensitivity in the (+) RB-ULNT group. LEVEL OF EVIDENCE 3a.
Collapse
|
131
|
The mirror-image pain: an unclered phenomenon and its possible mechanism. Neurosci Biobehav Rev 2009; 34:528-32. [PMID: 19883682 DOI: 10.1016/j.neubiorev.2009.10.011] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 09/24/2009] [Accepted: 10/22/2009] [Indexed: 01/04/2023]
Abstract
The contralateral allodynia to an injury has been described both in humans and various models of neuropathic and inflammatory pain in rats. In this article, the occurrence of mirror-image pain (MIP) in human beings and animals were reviewed and the possible mechanism of MIP reported was summarized. Last, according to the literature published, we raise some speculation about the possible mechanism underlying MIP.
Collapse
|
132
|
Costigan M, Scholz J, Woolf CJ. Neuropathic pain: a maladaptive response of the nervous system to damage. Annu Rev Neurosci 2009; 32:1-32. [PMID: 19400724 DOI: 10.1146/annurev.neuro.051508.135531] [Citation(s) in RCA: 1343] [Impact Index Per Article: 89.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Neuropathic pain is triggered by lesions to the somatosensory nervous system that alter its structure and function so that pain occurs spontaneously and responses to noxious and innocuous stimuli are pathologically amplified. The pain is an expression of maladaptive plasticity within the nociceptive system, a series of changes that constitute a neural disease state. Multiple alterations distributed widely across the nervous system contribute to complex pain phenotypes. These alterations include ectopic generation of action potentials, facilitation and disinhibition of synaptic transmission, loss of synaptic connectivity and formation of new synaptic circuits, and neuroimmune interactions. Although neural lesions are necessary, they are not sufficient to generate neuropathic pain; genetic polymorphisms, gender, and age all influence the risk of developing persistent pain. Treatment needs to move from merely suppressing symptoms to a disease-modifying strategy aimed at both preventing maladaptive plasticity and reducing intrinsic risk.
Collapse
Affiliation(s)
- Michael Costigan
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02129, USA.
| | | | | |
Collapse
|
133
|
Evidence for a role of heat shock protein-90 in toll like receptor 4 mediated pain enhancement in rats. Neuroscience 2009; 164:1821-32. [PMID: 19788917 DOI: 10.1016/j.neuroscience.2009.09.046] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 09/06/2009] [Accepted: 09/19/2009] [Indexed: 11/21/2022]
Abstract
Spinal cord microglial toll-like receptor 4 (TLR4) has been implicated in enhancing neuropathic pain and opposing morphine analgesia. The present study was initiated to explore TLR4-mediated pain modulation by intrathecal lipopolysaccharide, a classic TLR4 agonist. However, our initial study revealed that intrathecal lipopolysaccharide failed to induce low-threshold mechanical allodynia in naive rats, suggestive that TLR4 agonism may be insufficient to enhance pain. These studies explore the possibility that a second signal is required; namely, heat shock protein-90 (HSP90). This candidate was chosen for study given its known importance as a regulator of TLR4 signaling. A combination of in vitro TLR4 cell signaling and in vivo behavioral studies of pain modulation suggest that TLR4-enhancement of neuropathic pain and TLR4-suppression of morphine analgesia each likely require HSP90 as a cofactor for the effects observed. In vitro studies revealed that dimethyl sulfoxide (DMSO) enhances HSP90 release, suggestive that this may be a means by which DMSO enhances TLR4 signaling. While 2 and 100 microg lipopolysaccharide intrathecally did not induce mechanical allodynia across the time course tested, co-administration of 1 microg lipopolysaccharide with a drug that enhances HSP90-mediated TLR4 signaling now induced robust allodynia. In support of this allodynia being mediated via a TLR4/HSP90 pathway, it was prevented or reversed by intrathecal co-administration of a HSP90 inhibitor, a TLR4 inhibitor, a microglia/monocyte activation inhibitor (as monocyte-derived cells are the predominant cell type expressing TLR4), and interleukin-1 receptor antagonist (as this proinflammatory cytokine is a downstream consequence of TLR4 activation). Together, these results suggest for the first time that TLR4 activation is necessary but not sufficient to induce spinally mediated pain enhancement. Rather, the data suggest that TLR4-dependent pain phenomena may require contributions by multiple components of the TLR4 receptor complex.
Collapse
|
134
|
Alexander JK, DeVries AC, Kigerl KA, Dahlman JM, Popovich PG. Stress exacerbates neuropathic pain via glucocorticoid and NMDA receptor activation. Brain Behav Immun 2009; 23:851-60. [PMID: 19361551 PMCID: PMC2735409 DOI: 10.1016/j.bbi.2009.04.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2009] [Revised: 03/31/2009] [Accepted: 04/01/2009] [Indexed: 12/22/2022] Open
Abstract
There is growing recognition that psychological stress influences pain. Hormones that comprise the physiological response to stress (e.g., corticosterone; CORT) may interact with effectors of neuropathic pain. To test this hypothesis, mice received a spared nerve injury (SNI) after exposure to 60 min restraint stress. In stressed mice, allodynia was consistently increased. The mechanism(s) underlying the exacerbated pain response involves CORT acting via glucocorticoid receptors (GRs); RU486, a GR antagonist, prevented the stress-induced increase in allodynia whereas exogenous administration of CORT to non-stressed mice reproduced the allodynic response caused by stress. Since nerve injury-induced microglial activation has been implicated in the onset and propagation of neuropathic pain, we evaluated cellular and molecular indices of microglial activation in the context of stress. Activation of dorsal horn microglia was accelerated by stress; however, this effect was transient and was not associated with the onset or maintenance of a pro-inflammatory phenotype. Stress-enhanced allodynia was associated with increased dorsal horn extracellular signal-regulated kinase phosphorylation (pERK). ERK activation could indicate a stress-mediated increase in glutamatergic signaling, therefore mice were treated prior to SNI and stress with memantine, an N-methyl-D-aspartate receptor (NMDAR) antagonist. Memantine prevented stress-induced enhancement of allodynia after SNI. These data suggest that the hormonal responses elicited by stress exacerbate neuropathic pain through enhanced central sensitization. Moreover, drugs that inhibit glucocorticoids (GCs) and/or NMDAR signaling could ameliorate pain syndromes caused by stress.
Collapse
Affiliation(s)
- Jessica K Alexander
- Neuroscience Graduate Studies Program, The Ohio State University, Columbus, OH 43210, USA
| | | | | | | | | |
Collapse
|
135
|
de la Llave-Rincón AI, Fernández-de-las-Peñas C, Fernández-Carnero J, Padua L, Arendt-Nielsen L, Pareja JA. Bilateral hand/wrist heat and cold hyperalgesia, but not hypoesthesia, in unilateral carpal tunnel syndrome. Exp Brain Res 2009; 198:455-63. [DOI: 10.1007/s00221-009-1941-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 07/01/2009] [Indexed: 11/30/2022]
|
136
|
Bove GM, Weissner W, Barbe MF. Long lasting recruitment of immune cells and altered epi-perineurial thickness in focal nerve inflammation induced by complete Freund's adjuvant. J Neuroimmunol 2009; 213:26-30. [PMID: 19564053 DOI: 10.1016/j.jneuroim.2009.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2009] [Revised: 05/27/2009] [Accepted: 06/04/2009] [Indexed: 10/20/2022]
Abstract
Immune-mediated nerve inflammation is involved in many painful states in humans, and causes axonal and behavioral changes in rats. While models of nerve inflammation have been characterized using electrophysiological and behavioral methods, the presence of immune cells has not been fully assessed. We inflamed rat sciatic nerves using complete Freund's adjuvant and quantified the presence of ED-1 macrophages and TCR-alphabeta T-cells for up to 12 weeks. We report that these immune cells are prominent extraneurally up to 12 weeks following the induction of inflammation. This observation does not easily correlate with inflammation-induced axonal mechanical sensitivity, which peaks within 1 week and is resolved after 8 weeks.
Collapse
Affiliation(s)
- Geoffrey M Bove
- Dept. of Research Administration, University of Southern Maine, 178 Science Building, P.O. Box 9300, Portland, ME 04104-9300, USA.
| | | | | |
Collapse
|
137
|
Miuchi S, Sakagami M, Tsuzuki K, Noguchi K, Mishiro Y, Katsura H. Taste disturbance after stapes surgery--clinical and experimental study. Acta Otolaryngol 2009:71-8. [PMID: 19848245 DOI: 10.1080/00016480902915731] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
CONCLUSION Most of the clinical cases experienced taste disturbance after stapes surgery, and in a few cases this disturbance persisted for a long time. The animal experiment suggested the role of geniculate ganglion (GG) cells in nerve generation. OBJECTIVES To clinically examine taste disorder and its recovery after stapes surgery and experimentally demonstrate a role of GG. PATIENTS AND METHODS Taste function after preservation of chorda tympani nerve (CTN) in stapes surgery was prospectively investigated with a questionnaire and electrogustometry (EGM). Further, expression of neurotrophic factors in GG after injury of CTN was examined by in situ hybridization histochemistry (ISSH) and RT-PCR. RESULTS Among the cases, 15/18 (83.3%) were associated with taste disturbance and 6/18 (33.3%) were associated with tongue numbness 2 weeks after surgery; however, the symptoms ceased in 14/18 cases (77.8%). Two weeks after surgery, the EGM threshold was found to be elevated in 15/18 cases (83.3%), while in 10/18 cases (55.6%), it did not decrease until 1 year after surgery. Expression of ISSH and amplified bands of BDNF and GFR increased at 7 and 14 days after nerve injury in ipsilateral GGs and also increased at 7 days on the contralateral side.
Collapse
|
138
|
Abstract
Hyperalgesia and allodynia are frequent symptoms of disease and may be useful adaptations to protect vulnerable tissues. Both may, however, also emerge as diseases in their own right. Considerable progress has been made in developing clinically relevant animal models for identifying the most significant underlying mechanisms. This review deals with experimental models that are currently used to measure (sect. II) or to induce (sect. III) hyperalgesia and allodynia in animals. Induction and expression of hyperalgesia and allodynia are context sensitive. This is discussed in section IV. Neuronal and nonneuronal cell populations have been identified that are indispensable for the induction and/or the expression of hyperalgesia and allodynia as summarized in section V. This review focuses on highly topical spinal mechanisms of hyperalgesia and allodynia including intrinsic and synaptic plasticity, the modulation of inhibitory control (sect. VI), and neuroimmune interactions (sect. VII). The scientific use of language improves also in the field of pain research. Refined definitions of some technical terms including the new definitions of hyperalgesia and allodynia by the International Association for the Study of Pain are illustrated and annotated in section I.
Collapse
Affiliation(s)
- Jürgen Sandkühler
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
139
|
Kanashiro A, Pessini AC, Machado RR, Malvar DDC, Aguiar FA, Soares DM, do Vale ML, de Souza GEP. Characterization and pharmacological evaluation of febrile response on zymosan-induced arthritis in rats. Am J Physiol Regul Integr Comp Physiol 2009; 296:R1631-40. [DOI: 10.1152/ajpregu.90527.2008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study investigated the febrile response in zymosan-induced arthritis, as well as the increase in PGE2concentration in the cerebrospinal fluid (CSF), along with the effects of antipyretic drugs on these responses in rats. Zymosan intra-articularly injected at the dose of 0.5 mg did not affect the body core temperature (Tc) compared with saline (control), whereas at doses of 1 and 2 mg, zymosan promoted a flattened increase in Tc and declined thereafter. The dose of 4 mg of zymosan was selected for further experiments because it elicited a marked and long-lasting Tc elevation starting at 3 1/2 h, peaking at 5 1/2 h, and remaining until 10 h. This temperature increase was preceded by a decrease in the tail skin temperature, as well as hyperalgesia and edema in the knee joint. No febrile response was observed in the following days. In addition, zymosan-induced fever was not modified by the sciatic nerve excision. Zymosan increased PGE2concentration in the CSF but not in the plasma. Oral pretreatment with ibuprofen (5–20 mg/kg), celecoxib (1–10 mg/kg), dipyrone (60–240 mg/kg), and paracetamol (100–200 mg/kg) or subcutaneous injection of dexamethasone (0.25–1.0 mg/kg) dose-dependently reduced or prevented the fever during the zymosan-induced arthritis. Celecoxib (5 mg/kg), paracetamol (150 mg/kg), and dipyrone (120 mg/kg) decreased CSF PGE2concentration and fever during zymosan-induced arthritis, suggesting the involvement of PGE2in this response.
Collapse
|
140
|
Eliav E, Benoliel R, Herzberg U, Kalladka M, Tal M. The role of IL-6 and IL-1beta in painful perineural inflammatory neuritis. Brain Behav Immun 2009; 23:474-84. [PMID: 19486649 DOI: 10.1016/j.bbi.2009.01.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 01/05/2009] [Accepted: 01/15/2009] [Indexed: 10/21/2022] Open
Abstract
UNLABELLED Inflammation along a nerve trunk (perineural inflammation), without detectable axonal damage, has been shown to induce transient pain in the organ supplied by the nerve. The aims of the present study were to study the role IL-6 and IL-1beta, in pain induced by perineural inflammation. METHODS IL-6 and IL-1beta secretion from rat's sciatic nerves, L-5 Dorsal Root Ganglia (DRG), and the hind paw skin, 3 and 8 days following exposure of the nerve to Complete Freund's Adjuvant (CFA), were measured using ELISA method. Hind paw tactile-allodynia, mechano-hyperalgesia, heat-allodynia and electrical detection thresholds were tested up to 8 days following the application of CFA, IL-6 or IL-1beta adjacent to the sciatic nerve trunk. Employing electrophysiological recording, saphenous nerve spontaneous activity, nerve trunk mechano-sensitivity and paw tactile detection threshold (determined by recording action potential induced by the lowest mechanical stimulus) were assessed 3 and 8 days following exposure of the nerve trunk to CFA, IL-6, or IL-1beta. RESULTS IL-6 and IL-1beta secretion from the nerve was significantly elevated on the 3rd day post-operation (DPO). On the 8th DPO, IL-6 levels returned to baseline while IL-1beta levels remained significantly elevated. The DRG cytokine's level was increased on the 3rd and 8th DPOs, contralateral cytokine's level was increased on the 3rd DPO. The skin IL-6 level was increased bilaterally on the 3rd DPO and returned to baseline on the 8th DPO. IL-1beta levels increased in the affected side on the 3rd and bilaterally on the 8th DPO. Direct application of IL-6 or CFA on the sciatic nerve induced significant hind paw tactile-allodynia from the 1st to 5th DPOs, reduced electrical detection threshold from the 1st to 3rd DPOs, mechano-hyperalgesia from 3rd to 5th DPOs and heat-allodynia on the 3rd DPO. Direct application of IL-1beta induced paw tactile and heat-allodynia on the 7-8th DPOs and mechano-hyperalgesia on the 5-8th DPOs. Perineural inflammation significantly increased spontaneous activity myelinated fibres 3 and 8 days following the application. Direct application of IL-6 induced elevation of spontaneous activity on the 3rd while IL-1beta on the 8th DPO. Nerve mechano-sensitivity was significantly increased on the 3rd day following exposure to CFA and IL-6 and on the 8th following CFA application. The rat's paw lowest mechanical force necessary for induction of action potential, was significantly reduced 3 days following CFA application. CONCLUSION IL-6 and IL-1beta play an important role in pain induced by perineural inflammation. IL-6 activity is more prominent immediately following application (2-5th DPOs), while IL-1beta, activity is more significant in a later stage (5-8th DPOs).
Collapse
Affiliation(s)
- Eli Eliav
- UMDNJ-New Jersey Dental School, Carmel Endowed Chair in Algesiology, Department of Diagnostic Sciences, Division of Orofacial Pain, 110 Bergen Street, Newark, NJ 07103, USA.
| | | | | | | | | |
Collapse
|
141
|
Fernandez-de-las-Penas C, de la Llave-Rincon AI, Fernandez-Carnero J, Cuadrado ML, Arendt-Nielsen L, Pareja JA. Bilateral widespread mechanical pain sensitivity in carpal tunnel syndrome: evidence of central processing in unilateral neuropathy. Brain 2009; 132:1472-9. [DOI: 10.1093/brain/awp050] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
142
|
Park JS, Voitenko N, Petralia RS, Guan X, Xu JT, Steinberg JP, Takamiya K, Sotnik A, Kopach O, Huganir RL, Tao YX. Persistent inflammation induces GluR2 internalization via NMDA receptor-triggered PKC activation in dorsal horn neurons. J Neurosci 2009; 29:3206-19. [PMID: 19279258 PMCID: PMC2664544 DOI: 10.1523/jneurosci.4514-08.2009] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2008] [Revised: 02/04/2009] [Accepted: 02/09/2009] [Indexed: 01/23/2023] Open
Abstract
Spinal cord GluR2-lacking AMPA receptors (AMPARs) contribute to nociceptive hypersensitivity in persistent pain, but the molecular mechanisms underlying this event are not completely understood. We report that complete Freund's adjuvant (CFA)-induced peripheral inflammation induces synaptic GluR2 internalization in dorsal horn neurons during the maintenance of CFA-evoked nociceptive hypersensitivity. This internalization is initiated by GluR2 phosphorylation at Ser(880) and subsequent disruption of GluR2 binding to its synaptic anchoring protein (GRIP), resulting in a switch of GluR2-containing AMPARs to GluR2-lacking AMPARs and an increase of AMPAR Ca(2+) permeability at the synapses in dorsal horn neurons. Spinal cord NMDA receptor-mediated triggering of protein kinase C (PKC) activation is required for the induction and maintenance of CFA-induced dorsal horn GluR2 internalization. Moreover, preventing CFA-induced spinal GluR2 internalization through targeted mutation of the GluR2 PKC phosphorylation site impairs CFA-evoked nociceptive hypersensitivity during the maintenance period. These results suggest that dorsal horn GluR2 internalization might participate in the maintenance of NMDA receptor/PKC-dependent nociceptive hypersensitivity in persistent inflammatory pain.
Collapse
Affiliation(s)
- Jang-Su Park
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Nana Voitenko
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
| | - Ronald S. Petralia
- Laboratory of Neurochemistry, National Institute of Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Xiaowei Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Ji-Tian Xu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | | | | | - Andrij Sotnik
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
| | - Olga Kopach
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
| | - Richard L. Huganir
- Departments of Neuroscience and
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - Yuan-Xiang Tao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| |
Collapse
|
143
|
Abstract
Many are frustrated with the lack of translational progress in the pain field, in which huge gains in basic science knowledge obtained using animal models have not led to the development of many new clinically effective compounds. A careful re-examination of animal models of pain is therefore warranted. Pain researchers now have at their disposal a much wider range of mutant animals to study, assays that more closely resemble clinical pain states, and dependent measures beyond simple reflexive withdrawal. However, the complexity of the phenomenon of pain has made it difficult to assess the true value of these advances. In addition, pain studies are importantly affected by a wide range of modulatory factors, including sex, genotype and social communication, all of which must be taken into account when using an animal model.
Collapse
Affiliation(s)
- Jeffrey S Mogil
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada.
| |
Collapse
|
144
|
Amaya F, Samad TA, Barrett L, Broom DC, Woolf CJ. Periganglionic inflammation elicits a distally radiating pain hypersensitivity by promoting COX-2 induction in the dorsal root ganglion. Pain 2009; 142:59-67. [PMID: 19135800 PMCID: PMC2755568 DOI: 10.1016/j.pain.2008.11.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 11/20/2008] [Accepted: 11/21/2008] [Indexed: 12/19/2022]
Abstract
We have developed a model in which inflammation contiguous to and within a dorsal root ganglion (DRG) was generated by local application of complete Freund's adjuvant (CFA) to the L4 lumbar spinal nerve as it exits from the intervertebral foramen. The periganglionic inflammation (PGI) elicited a marked reduction in withdrawal threshold to mechanical stimuli and an increase in heat pain sensitivity in the ipsilateral hindpaw in the absence of any hindpaw inflammation. The pain sensitivity appeared within hours and lasted for a week. The PGI also induced a prominent increase in IL-1beta and TNF-alpha levels in the DRG and of cyclooxygenase-2 (COX-2) expression in neurons and satellite cells. A selective COX-2 inhibitor reduced the PGI-induced hyperalgesia. We also show that IL-1beta induces COX-2 expression and prostaglandin release in DRG neurons in vitro in a MAP kinase-dependent fashion. The COX-2 induction was prevented by ERK and p38 inhibitors. We conclude that periganglionic inflammation increases cytokine levels, including IL-1beta, leading to the transcription of COX-2 and prostaglandin production in the affected DRG, and thereby to the development of a dermatomally distributed pain hypersensitivity.
Collapse
Affiliation(s)
- Fumimasa Amaya
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, USA
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Japan
| | - Tarek A. Samad
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, USA
| | - Lee Barrett
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, USA
| | - Daniel C. Broom
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, USA
| | - Clifford J. Woolf
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, USA
| |
Collapse
|
145
|
Garraway SM, Xu Q, Inturrisi CE. siRNA-mediated knockdown of the NR1 subunit gene of the NMDA receptor attenuates formalin-induced pain behaviors in adult rats. THE JOURNAL OF PAIN 2009; 10:380-90. [PMID: 19185544 DOI: 10.1016/j.jpain.2008.09.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Revised: 08/28/2008] [Accepted: 09/18/2008] [Indexed: 01/21/2023]
Abstract
UNLABELLED NMDA receptors in the spinal cord dorsal horn (SCDH) mediate some inflammatory pain behaviors. Here, we used rAAV vectors expressing an active small interfering RNA (siRNA) (vector 6) targeting the essential NR1 subunit of the NMDA receptor or a mismatch siRNA (vector MM-6) sequence to determine the consequences of RNAi-mediated knockdown of NR1 expression on NMDA receptor levels and formalin-induced pain behaviors in adult rats. Three weeks after intraparenchymal administration of the vector 6 into the right lumbar SCDH, NR1 mRNA and protein levels were significantly reduced (P < .01) in the ipsilateral SCDH compared with the contralateral SCDH but not in vector MM-6 or non-vector control animals. Formalin-induced phase 2 nociceptive response was significantly reduced (P < .05) in vector 6 animals compared with controls. Although neither vector affected normal mechanical threshold, vector 6 provided protection from the mechanical allodynia seen in controls at 24 hours after intraplantar formalin. Vector 6 also prevented the increase in phosphorylated NR1 levels seen in the ipsilateral SCDH of control rats 45 minutes after formalin. These results indicate that vector-derived siRNAs can effectively produce spatial knockdown of NR1 gene expression, and this knockdown selectively attenuates in vivo NMDA receptor-mediated formalin behaviors and NR1 phosphorylation in the rat. PERSPECTIVE This study reveals that a single administration of an siRNA-expressing viral vector produces significant knockdown of the NR1 gene in the SCDH of adult rats. This preclinical study demonstrates the use of RNAi to target the expression of genes mediating pain and the therapeutic potential of this approach.
Collapse
Affiliation(s)
- Sandra M Garraway
- Department of Pharmacology, Weill Cornell Medical College, New York, New York 10065-4896, USA
| | | | | |
Collapse
|
146
|
Kim YK, Park JY, Hwang JH. Comparison of antiallodynic effect of intrathecal morphine, brimonidine and rilmenidine between neuritis and ligation injury induced neuropathic pain. Korean J Anesthesiol 2009; 56:425-432. [DOI: 10.4097/kjae.2009.56.4.425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Young-Kug Kim
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jong-Yeon Park
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jai-Hyun Hwang
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| |
Collapse
|
147
|
Hutchinson MR, Zhang Y, Brown K, Coats BD, Shridhar M, Sholar PW, Patel SJ, Crysdale NY, Harrison JA, Maier SF, Rice KC, Watkins LR. Non-stereoselective reversal of neuropathic pain by naloxone and naltrexone: involvement of toll-like receptor 4 (TLR4). Eur J Neurosci 2008; 28:20-9. [PMID: 18662331 DOI: 10.1111/j.1460-9568.2008.06321.x] [Citation(s) in RCA: 309] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Although activated spinal cord glia contribute importantly to neuropathic pain, how nerve injury activates glia remains controversial. It has recently been proposed, on the basis of genetic approaches, that toll-like receptor 4 (TLR4) may be a key receptor for initiating microglial activation following L5 spinal nerve injury. The present studies extend this idea pharmacologically by showing that TLR4 is key for maintaining neuropathic pain following sciatic nerve chronic constriction injury (CCI). Established neuropathic pain was reversed by intrathecally delivered TLR4 receptor antagonists derived from lipopolysaccharide. Additionally, (+)-naltrexone, (+)-naloxone, and (-)-naloxone, which we show here to be TLR4 antagonists in vitro on both stably transfected HEK293-TLR4 and microglial cell lines, suppressed neuropathic pain with complete reversal upon chronic infusion. Immunohistochemical analyses of spinal cords following chronic infusion revealed suppression of CCI-induced microglial activation by (+)-naloxone and (-)-naloxone, paralleling reversal of neuropathic pain. Together, these CCI data support the conclusion that neuron-to-glia signaling through TLR4 is important not only for initiating neuropathic pain, as suggested previously, but also for maintaining established neuropathic pain. Furthermore, these studies suggest that the novel TLR4 antagonists (+)-naloxone and (-)-naloxone can each fully reverse established neuropathic pain upon multi-day administration. This finding with (+)-naloxone is of potential clinical relevance. This is because (+)-naloxone is an antagonist that is inactive at the (-)-opioid selective receptors on neurons that produce analgesia. Thus, these data suggest that (+)-opioid antagonists such as (+)-naloxone may be useful clinically to suppress glial activation, yet (-)-opioid agonists suppress pain.
Collapse
Affiliation(s)
- Mark R Hutchinson
- Department of Psychology and The Center for Neuroscience, Campus Box 345, University of Colorado at Boulder, Boulder, CO 80309-0345, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
148
|
Mental nerve neuropathy: patient characteristics and neurosensory changes. ACTA ACUST UNITED AC 2008; 106:364-70. [DOI: 10.1016/j.tripleo.2007.12.037] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 12/20/2007] [Accepted: 12/25/2007] [Indexed: 11/24/2022]
|
149
|
Hulata D, Hughes WF, Shott S, Kroin JS, Gonzalez MH, Kerns JM. Early behavioral and histological outcomes following a novel traumatic partial nerve lesion. J Neurosci Methods 2008; 172:236-44. [DOI: 10.1016/j.jneumeth.2008.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 04/24/2008] [Accepted: 05/03/2008] [Indexed: 11/28/2022]
|
150
|
Levin ME, Jin JG, Ji RR, Tong J, Pomonis JD, Lavery DJ, Miller SW, Chiang LW. Complement activation in the peripheral nervous system following the spinal nerve ligation model of neuropathic pain ☆. Pain 2008; 137:182-201. [DOI: 10.1016/j.pain.2007.11.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 10/15/2007] [Accepted: 11/07/2007] [Indexed: 10/22/2022]
|