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Chakravarthy KV, Xing F, Bruno K, Kent AR, Raza A, Hurlemann R, Kinfe TM. A Review of Spinal and Peripheral Neuromodulation and Neuroinflammation: Lessons Learned Thus Far and Future Prospects of Biotype Development. Neuromodulation 2018; 22:235-243. [DOI: 10.1111/ner.12859] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 07/18/2018] [Accepted: 08/15/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Krishnan V. Chakravarthy
- Department of Anesthesiology and Pain MedicineUniversity of California San Diego Health Sciences San Diego CA USA
- VA San Diego Healthcare System San Diego CA USA
| | - Fang Xing
- Department of Anesthesiology and Pain MedicineBrigham and Women's Hospital Boston MA USA
| | - Kelly Bruno
- Department of Anesthesiology and Pain MedicineUniversity of California San Diego Health Sciences San Diego CA USA
- VA San Diego Healthcare System San Diego CA USA
| | | | - Adil Raza
- Neuromodulation Division, Abbott Plano TX USA
| | - Rene Hurlemann
- Department of Psychiatry, Division of Medical Psychology (NEMO Neuromodulation of Emotions)Rheinische Friedrich Wilhelms‐University Hospital Bonn Germany
| | - Thomas M. Kinfe
- Department of Psychiatry, Division of Medical Psychology (NEMO Neuromodulation of Emotions)Rheinische Friedrich Wilhelms‐University Hospital Bonn Germany
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Xu Y, Hong S, Zhao X, Wang S, Xu Z, Ding S, Zhang K, Zhang Y, Xu L, Yu N, Zhao T, Yan Y, Yang F, Liu Y, Yu K, Liu B, Guo Y, Pang G. Acupuncture Alleviates Rheumatoid Arthritis by Immune-Network Modulation. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2018; 46:997-1019. [DOI: 10.1142/s0192415x18500520] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Rheumatoid arthritis (RA) is a chronic, systemic autoimmune inflammatory and debilitating disease that involves the systemic imbalance of the immune network. Previous studies have shown that acupuncture can help treat RA. However, its specific mechanisms are not fully understood. Thus, the present study was designed to clarify the mechanisms of acupuncture acted on RA via immune network modulation using complete Freund’s adjuvant (CFA)-induced arthritic rats. Results revealed that manual acupuncture (MA) could alleviate the inflammation and pain of infected joints. Moreover, MA could effectively stimulate the innate immune cytokines (IL-1[Formula: see text], IL-1[Formula: see text], IL-6, IL-7, IL-18, TNF-[Formula: see text]) and adaptive immunity cytokines (IL-2, IL-12, IFN-[Formula: see text], IL-4, IL-5, IL-10, IL-13, IL-17) as the main part of the immune response and repaired damage of RA. These complex immunomodulatory processes were analyzed quantitatively by cell–cell communication (CCC) networks. The CCC networks demonstrated that the immune networks were enhanced with the development of RA, while MA enhanced the immune networks in the early stage to act on RA and promoted the immune-network to a normal level at the late stage. Moreover, we found that monocyte/macrophage and endothelial cells were the key cells of innate immunity and body cells; TH1, TH2 and B cells were the key cells of adaptive immunity, which were also the main target cells for MA regulation.
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Affiliation(s)
- Yuan Xu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Shouhai Hong
- Acupuncture Department, Zhejiang Provincial Hospital of TCM, Hangzhou, Zhejiang 310006, P. R. China
| | - Xue Zhao
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Shenjun Wang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Zhifang Xu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Shasha Ding
- Rehabilitation Center-Department of Acupuncture Physiotherapy, Tianjin Nankai Hospital, Tianjin 300100, P. R. China
| | - Kuo Zhang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Yiping Zhang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Lianjie Xu
- Tianjin Key Laboratory of Food Biotechnology, Faculty of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, P. R. China
| | - Nannan Yu
- Department of Traditional Chinese Medicine, Xijing Hospital, The Fourth Military Medical University, Xi’an, Shanxi 710032, P. R. China
| | - Tianyi Zhao
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Yawen Yan
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Fuming Yang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Yangyang Liu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Kun Yu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Baohu Liu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Yi Guo
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
- College of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, P. R. China
| | - Guangchang Pang
- Tianjin Key Laboratory of Food Biotechnology, Faculty of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, P. R. China
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3
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Abstract
In the last decade, preclinical investigations of electroacupuncture mechanisms on persistent tissue injury (inflammatory), nerve injury (neuropathic), cancer, and visceral pain have increased. These studies show that electroacupuncture activates the nervous system differently in health than in pain conditions, alleviates both sensory and affective inflammatory pain, and inhibits inflammatory and neuropathic pain more effectively at 2 to 10 Hz than at 100 Hz. Electroacupuncture blocks pain by activating a variety of bioactive chemicals through peripheral, spinal, and supraspinal mechanisms. These include opioids, which desensitize peripheral nociceptors and reduce proinflammatory cytokines peripherally and in the spinal cord, and serotonin and norepinephrine, which decrease spinal N-methyl-D-aspartate receptor subunit GluN1 phosphorylation. Additional studies suggest that electroacupuncture, when combined with low dosages of conventional analgesics, provides effective pain management which can forestall the side effects of often-debilitating pharmaceuticals.
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Affiliation(s)
- Ruixin Zhang
- Assistant Professor, Center for Integrative Medicine, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Lixing Lao
- Professor, Center for Integrative Medicine, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Ke Ren
- Professor, Department of Neural and Pain Sciences, Dental School, University of Maryland, Baltimore, Maryland
| | - Brian M. Berman
- Professor, Center for Integrative Medicine, School of Medicine, University of Maryland, Baltimore, Maryland
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Pamenter ME, Shin DSH, Buck LT. Adenosine A1 receptor activation mediates NMDA receptor activity in a pertussis toxin-sensitive manner during normoxia but not anoxia in turtle cortical neurons. Brain Res 2008; 1213:27-34. [DOI: 10.1016/j.brainres.2008.03.047] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 03/18/2008] [Accepted: 03/20/2008] [Indexed: 10/22/2022]
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Schneider SP, Walker TM. Morphology and electrophysiological properties of hamster spinal dorsal horn neurons that express VGLUT2 and enkephalin. J Comp Neurol 2007; 501:790-809. [PMID: 17299755 DOI: 10.1002/cne.21292] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The excitatory amino acid glutamate mediates transmission at spinal synapses, including those formed by sensory afferent fibers and by intrinsic interneurons. The identity and physiological properties of glutamatergic dorsal horn neurons are poorly characterized despite their importance in spinal sensory circuits. Moreover, many intrinsic spinal glutamatergic synapses colocalize the opioid peptide enkephalin (ENK), but the neurons to which they belong are yet to be identified. Therefore, we used immunohistochemistry and confocal microscopy to investigate expression of the VGLUT2 vesicular glutamate transporter, an isoform reported in nonprimary afferent spinal synapses, and ENK in electrophysiologically identified neurons of hamster spinal dorsal horn. VGLUT2 immunoreactivity was localized in restricted fashion to axon varicosities of neurons recorded from laminae II-V, although the occurrence of immunolabeling in individual varicosities varied widely between cells (39 +/- 36%, n = 31 neurons). ENK colocalized with VGLUT2 in up to 77% of varicosities (17 +/- 21%, n = 21 neurons). The majority of neurons expressing VGLUT2 and/or ENK had axons with dense local terminations or projections consistent with propriospinal functions. VGLUT2 and ENK labeling were not correlated with cellular morphology, intrinsic membrane properties, firing patterns, or synaptic responses to sensory afferent stimulation. However, VGLUT2 expression was significantly higher in neurons with depolarized resting membrane potential. The results are new evidence for a population of dual-function dorsal horn interneurons that might provide another mechanism for limiting excitation within dorsal horn circuits during periods of strong sensory activation.
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Affiliation(s)
- Stephen P Schneider
- Department of Physiology and Neuroscience Program, Michigan State University, E. Lansing, Michigan 48824-3320, USA.
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Brainin-Mattos J, Smith ND, Malkmus S, Rew Y, Goodman M, Taulane J, Yaksh TL. Cancer-related bone pain is attenuated by a systemically available delta-opioid receptor agonist. Pain 2006; 122:174-81. [PMID: 16545911 DOI: 10.1016/j.pain.2006.01.032] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Revised: 01/10/2006] [Accepted: 01/26/2006] [Indexed: 11/16/2022]
Abstract
Patients with bone cancer report severe pain and receive mu-opioids. We developed a family of peptidomimetic delta-agonists, one of which H2N-Tyr-dVal-Gly-Phe-Ala-OH ([dVal(L)2,Ala(L)5]E) binds with a 1700x affinity at the delta versus mu receptor. To examine the systemic analgesic efficacy of this delta-agonist versus morphine in osteosarcoma pain, osteosarcoma cells are injected into one femur of the anesthetized mouse. After 10-18 days, a decalcification of the injected femur occurs along with a pronounced tactile allodynia. IP morphine and [dVal(L)2,Ala(L)5]E produced a dose-dependent reversal of allodynia with the respective ED50 values being 5.3+/-1.9 mg/kg for morphine and 1.3+/-0.3 mg/kg for [dVal(L)2,Ala(L)5]E. Plotting peak effect versus area under the analgesic curve for doses of morphine and [dVal(L)2,Ala(L)5]E revealed overlapping curves suggesting that for a given effect, [dVal(L)2,Ala(L)5]E produced a similar duration of action as morphine. These effects were reversed by IP naloxone (3 mg/kg). IP naltrindole (1 mg/kg) preferentially reversed [dVal(L)2,Ala(L)5]E. The upper dose effects of morphine but not [dVal(L)2,Ala(L)5]E were limited by pronounced hyperactivity. No other effects were noted. These results show that IP [dVal(L)2,Ala(L)5]E through a delta receptor produces analgesia equal in efficacy to that of morphine but with a 4.5-fold greater potency. Over the doses examined, morphine actions were side effect limited. The delta side effects were not so limited, suggesting a favorable therapeutic ratio for delta-agonists in this pain model. These studies suggest that a systemically delivered delta-opioid agonist has pronounced analgesic properties on a preclinical cancer pain model.
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Affiliation(s)
- Josue Brainin-Mattos
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
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Lee HJ, Choi HS, Jung CY, Ju JS, Kim SK, Bae YC, Ahn DK. Intracisternal NMDA produces analgesia in the orofacial formalin test of freely moving rats. Prog Neuropsychopharmacol Biol Psychiatry 2004; 28:497-503. [PMID: 15093957 DOI: 10.1016/j.pnpbp.2004.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/30/2004] [Indexed: 11/21/2022]
Abstract
The present study was performed to investigate the antinociceptive response to the intracisternal administration of NMDA in the orofacial area. To achieve this purpose, the effects of NMDA injected intracisternally on the orofacial formalin test were monitored in freely moving rats. We also investigated underlying the mechanisms of NMDA-induced antinociceptive response. Experiments were carried out on 80 male SD rats and surgical procedures were performed under pentobarbital sodium (40 mg/kg, i.p.). Fifty microliters of 5% formalin was applied subcutaneously to the vibrissa pad without any restraining of the animals. For each animal, the number of noxious behavioral responses and the time spent grooming, rubbing, and/or scratching the facial region proximal to the injection site were recorded for nine successive 5-min intervals. The orofacial formalin responses showed two distinct phases separated by a time of relative inactivity. Intracisternal administration of NMDA produced intense scratching behavioral responses with dose related manner. NMDA injected intracisternally 30 min prior to formalin injection, however, inhibited noxious behavioral responses produced by a formalin injection significantly. Pretreatment with naloxone 20 min prior to NMDA injection abolished the inhibition of number of scratches and the duration of scratching produced by the intracisternal injection of NMDA in the late phase. Pretreatment with L-NAME, NO synthesis inhibitor, however, did not affect the antinociceptive response produced by NMDA injected intracisternally. These results suggest that NMDA injected intracisternally produces brief pain behavioral responses and also produces delayed antinociceptive effects in the orofacial formalin test. The opioid pathway seems to be involved in the NMDA-induced antinociception in the orofacial area.
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Affiliation(s)
- Ho Jeong Lee
- Department of Oral Physiology and Neurobiology, School of Dentistry, Kyungpook National University, 188-1, Samduck 2 ga, Chung-gu, Daegu (700-412), South Korea
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8
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Ahn DK, Jung CY, Lee HJ, Choi HS, Ju JS, Bae YC. Peripheral glutamate receptors participate in interleukin-1β-induced mechanical allodynia in the orofacial area of rats. Neurosci Lett 2004; 357:203-6. [PMID: 15003285 DOI: 10.1016/j.neulet.2003.12.097] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2003] [Revised: 12/17/2003] [Accepted: 12/18/2003] [Indexed: 11/28/2022]
Abstract
The present study was performed to examine peripheral cytokine-induced mechanical allodynia in the orofacial area and to investigate whether peripheral excitatory amino acids participate in the cytokine-induced mechanical allodynia. Experiments were carried out on male Sprague-Dawley rats. After interleukin-1beta (IL-1beta) was applied subcutaneously to the orofacial area, we examined withdrawal responses produced by air puffs applied to the IL-1beta injection site. The threshold of air puffs that produced withdrawal behavioral responses decreased significantly in a dose-dependent manner after injection of IL-1beta. Pretreatment with an IL-1 receptor antagonist abolished the decrease in the threshold of air puffs. Pretreatment with dl-2-amino-5-phosphonvaleric acid, an N-methyl-d-aspartic acid (NMDA) receptor antagonist, did not affect IL-1beta-induced mechanical allodynia. However, pretreatment with 6,7-dinitroquinoxaline-2,3-dione, a non-NMDA receptor antagonist, abolished the decrease in the threshold of air puffs. These results suggest that peripheral cytokine can produce mechanical allodynia in the orofacial area and that excitatory amino acids can modulate IL-1beta-induced mechanical allodynia via non-NMDA receptors.
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Affiliation(s)
- D K Ahn
- Department of Oral Physiology, School of Dentistry, Kyungpook National University, 188-1 Sam Deok 2ga, Chung-gu, Daegu 700-412, South Korea.
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Aicher SA, Goldberg A, Sharma S. Co-localization of mu opioid receptor and N-methyl-D-aspartate receptor in the trigeminal dorsal horn. THE JOURNAL OF PAIN 2003; 3:203-10. [PMID: 14622774 DOI: 10.1054/jpai.2002.123709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Antagonists acting at the N-methyl-D-aspartate (NMDA) receptor can block the development of tolerance to the analgesic effects of [mu ] opioid receptor (MOR) ligands, such as morphine, and can also enhance the analgesic efficacy of opioids. These findings have led to the hypothesis that interactions between NMDA receptor and MOR ligands may be due to the co-localization of these receptors on neurons in the dorsal horn. We used dual immunogold and immunoperoxidase immunocytochemistry for MOR1 and NMDAR1 to determine the degree of co-localization of these receptors in neurons of the trigeminal dorsal horn. By use of electron microscopy, we found that both receptors were primarily located in dendrites and to a lesser extent in perikarya, axons, axon terminals, and glia. With regard to the degree of co-localization in dendrites, 63% of MOR1-labeled dendrites also contained NMDAR1, whereas 61% of NMDAR1-labeled dendrites also contained MOR1. Most of the dual-labeled profiles (94%) were classified as dendrites, with the remainder being axons, axon terminals, or perikarya. These results suggest that direct interactions between MOR and NMDA receptor ligands are likely mediated through shared dendritic targets in the dorsal horn. Less frequently, we found evidence for modulation of afferents to MOR-containing neurons through presynaptic NMDA receptors.
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Affiliation(s)
- Sue A Aicher
- Oregon Health Sciences University, Neurological Sciences Institute, Beaverton, 97006, USA.
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10
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Storer RJ, Akerman S, Goadsby PJ. Characterization of opioid receptors that modulate nociceptive neurotransmission in the trigeminocervical complex. Br J Pharmacol 2003; 138:317-24. [PMID: 12540522 PMCID: PMC1573664 DOI: 10.1038/sj.bjp.0705034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2002] [Revised: 09/10/2002] [Accepted: 10/08/2002] [Indexed: 11/08/2022] Open
Abstract
1. Opioid agonists have been used for many years to treat all forms of headache, including migraine. We sought to characterize opioid receptors involved in craniovascular nociceptive pathways by in vivo microiontophoresis of micro -receptor agonists and antagonists onto neurons in the trigeminocervical complex of the cat. 2. Cats were anaesthetized with alpha-chloralose 60 mg kg(-1), i.p. and 20 mg kg(-1), i.v. supplements after induction and surgical preparation using halothane. Units were identified in the trigeminocervical complex responding to supramaximal electrical stimulation of the superior sagittal sinus, and extracellular recordings of activity made. 3. Seven- or nine-barrelled glass micropipettes incorporating tungsten recording electrodes in their centre barrels were used for microiontophoresis of test substances onto cell bodies. 4. Superior sagittal sinus (SSS)-linked cells whose firing was evoked by microiontophoretic application of L-glutamate (n=8 cells) were reversibly inhibited by microiontophoresis of H(2)N-Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol (DAMGO) (n=12), a selective micro -receptor agonist, in a dose dependent manner, but not by control ejection of sodium or chloride ions from a barrel containing saline. 5. The inhibition by DAMGO of SSS-linked neurons activated with L-glutamate could be antagonized by microiontophoresis of selective micro -receptor antagonists D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) (CTOP) or D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP), or both, in all cells tested (n=4 and 6, respectively). 6. Local iontophoresis of DAMGO during stimulation of the superior sagittal sinus resulted in a reduction in SSS-evoked activity. This effect was substantially reversed 10 min after cessation of iontophoresis. The effect of DAMGO was markedly inhibited by co-iontophoresis of CTAP. 7. Thus, we found that micro -receptors modulate nociceptive input to the trigeminocervical complex. Characterizing the sub-types of opioid receptors that influence trigeminovascular nociceptive transmission is an important component to understanding the pharmacology of this synapse, which is pivotal in primary neurovascular headache.
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MESH Headings
- Animals
- Cats
- Dose-Response Relationship, Drug
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Neural Pathways/drug effects
- Neural Pathways/physiology
- Pain Measurement/drug effects
- Pain Measurement/methods
- Receptors, Opioid/agonists
- Receptors, Opioid/classification
- Receptors, Opioid/physiology
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/classification
- Receptors, Opioid, mu/physiology
- Superior Cervical Ganglion/drug effects
- Superior Cervical Ganglion/physiology
- Trigeminal Nuclei/drug effects
- Trigeminal Nuclei/physiology
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Affiliation(s)
- R J Storer
- Headache Group, Institute of Neurology, Queen Square, London WC1N 3BG
| | - S Akerman
- Headache Group, Institute of Neurology, Queen Square, London WC1N 3BG
| | - P J Goadsby
- Headache Group, Institute of Neurology, Queen Square, London WC1N 3BG
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Staud R, Smitherman ML. Peripheral and central sensitization in fibromyalgia: pathogenetic role. Curr Pain Headache Rep 2002; 6:259-66. [PMID: 12095460 DOI: 10.1007/s11916-002-0046-1] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Characteristic symptoms of fibromyalgia syndrome include widespread pain, fatigue, sleep abnormalities, and distress. Patients with fibromyalgia show psychophysical evidence of mechanical, thermal, and electrical hyperalgesia. Peripheral and central abnormalities of nociception have been described in fibromyalgia. Important nociceptor systems in the skin and muscles seem to undergo profound changes in patients with fibromyalgia through unknown mechanisms. They include sensitization of vanilloid receptor, acid-sensing ion channel receptors, and purino-receptors. Tissue mediators of inflammation and nerve growth factors can excite these receptors and cause extensive changes in pain sensitivity, but patients with fibromyalgia lack consistent evidence for inflammatory soft tissue abnormalities. Therefore, recent investigations have focused on central nervous system mechanisms of pain in fibromyalgia.
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Affiliation(s)
- Roland Staud
- Division of Rheumatology and Clinical Immunology, University of Florida, PO Box 100221, Gainesville, FL 32610-0221, USA.
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12
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Cao CQ, Hong YG, Dray A, Perkins MN. Selective depression of nociceptive responses of dorsal horn neurones by SNC 80 in a perfused hindquarter preparation of adult mouse. Neuroscience 2002; 107:329-38. [PMID: 11731107 DOI: 10.1016/s0306-4522(01)00349-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
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, P<0.005), 30.1+/-5.4 (n=58, P<0.005) and 40.9+/-6.3 (n=29, P<0.005) spikes per stimulus respectively. In 5 of 22 cells, repetitive noxious electrical stimuli applied to the hindpaw for 20 s produced a progressive increase in spike number, the phenomenon known as 'wind-up' and/or hyperactivity. When the selective delta-opioid receptor agonist (+)-4-[(alpha R)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide (SNC 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, P<0.01), 66.5+/-16.6% (n=10, P<0.01) and 74.1+/-17.0% (n=10, P<0.01) respectively. The maximum depression by 5 microM SNC 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% (P<0.05, n=8), 34.2+/-6.1% (P<0.01, n=7) and 45.5+/-11.8% (P<0.05, n=5) respectively. In contrast, the responses of non-nociceptive dorsal horn neurones were not inhibited by SNC 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.
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Affiliation(s)
- C Q Cao
- Department of Pharmacology, AstraZeneca R&D Montreal, 7171 Frederick-Banting, St-Laurent (Montreal), QC, Canada H4S 1Z9.
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Luccarini P, Sessle BJ, Woda A. Superficial and deep convergent nociceptive neurons are differentially affected by N-methyl-D-aspartate applied on the brainstem surface of the rat medullary dorsal horn. Neuroscience 2002; 107:311-6. [PMID: 11731105 DOI: 10.1016/s0306-4522(01)00360-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The activation of N-methyl-D-aspartate receptors is implicated in the spinal and trigeminal processing of nociceptive information conveyed by convergent (wide dynamic range) neurons and particularly in C-fiber-evoked responses elicited by repetitive and high-intensity electrical stimulation of the neuronal receptive field. In this study, the effects of intrathecal NMDA application on the electrically evoked nociceptive responses of trigeminal subnucleus caudalis convergent neurons have been investigated. The total C-fiber-evoked activity triggered by 30 successive stimuli was divided into two components: the C-fiber input response and the 'wind-up' response. Application of 0.1 microg (in 50 microl) of NMDA evoked a bi-directional effect on the total C-fiber-evoked activity of 19 neurons tested. A significant increase in the total C-fiber-evoked activity was observed 15-25 min after the NMDA application for nine neurons located in superficial laminae II and III. In contrast, a significant decrease in the total C-fiber-evoked activity was observed 5-25 min after the NMDA application for 10 neurons located more deeply, in lamina V. The NMDA-induced modifications seen in the total C-fiber-evoked activity were likely a reflection of a significant increase or decrease in neuronal activity evoked by the C-fiber input rather than wind-up of the responses since the latter was not significantly modified by the NMDA application. These results provide evidence for a possible inhibitory role for NMDA-dependent interneurons of the superficial laminae of the medullary dorsal horn on the nociceptive activity of deep convergent neurons.
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Affiliation(s)
- P Luccarini
- Laboratoire de Physiologie Oro-Faciale, UFR d'Odontologie, Université d'Auvergne, Clermont-Ferrand, France.
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Koyuncuoğlu H, Nurten A, Enginar N, Ozerman B, Kara I. The effects of different 4-aminopyridine and morphine combinations on the intensity of morphine abstinence. Pharmacol Res 2001; 43:245-50. [PMID: 11401416 DOI: 10.1006/phrs.2000.0771] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The glutamatergic system is deeply involved in the development of opiate dependence and in the manifestation of opiate abstinence syndrome. In this study the effect of the increase in the endogenous glutamate (GLU) release due to 4-aminopyridine (4-AP), a potassium channel blocker, during the development of morphine (M) physical dependence and during the naloxone (NL)-precipitated abstinence syndrome was investigated. For the development of physical dependence M was intraperitoneally (i.p.) injected for 9 days 105 min following i.p. saline administration to a group of rats. In the first 3 days the dose of M was 10 mg x kg(-1). In the second 3 days the initial dose was doubled (20 mg x kg(-1)) and in the last 3 days the dose of M was raised to 40 mg x kg(-1). On day 10, the rats were divided into three groups at random and these three groups were i.p. given saline 105 min before 80 mg x kg(-1)M, 2 mg x kg(-1) 4-AP 105 min after 80 mg x kg(-1) M, and 80 mg x kg(-1) M 105 min before 2 mg x kg(-1) 4-AP, respectively. In a second group of rats, the rats were i.p. given 2 mg x kg(-1) 4-AP 105 min prior to M administration, which was increased every 3 days (10 mg x kg(-1), 20 mg x kg(-1), 40 mg x kg(-1)). On day 10, the rats were divided into two groups whose first injection was saline and 2 mg x kg(-1) 4-AP, respectively. The second injections of both groups after an interval of 105 min following the first one contained 80 mg x kg(-1) M. In contrast, one group of rats received only i.p. saline at every other injection time (the control group). Furthermore, another group of rats was i.p. administered 2 mg x kg(-1) 4-AP once a day, as the first injection. At the second injection time they were i.p. given saline. After a period of 15 min following the last administration on day 10, the rats belonging to all groups were i.p. injected with 2 mg x kg(-1) NL and immediately placed in a metal cage. Body weight loss (g), teeth chattering, rearing, wet-dog shaking, grooming, and jumping were determined or counted for 15 min. Penile erection, defecation, and diarrhoea were separately scored with one point for every individual occurrence, and the total score was named 'total number of others'. The administration of 4-AP before M appeared to intensify the development of dependence, and was most probably due to the Ca2+-induced inactivation of NMDA receptors as a result of excess release of GLU when the 4-AP took effect. The inactivation of NMDA receptors should have acted as a transient blockade of the receptors during the chronic administration period, and as well as after a single administration on day 10 before M injection and before abstinence. The intensification of the abstinence syndrome may be dependent on the excessive GLU released by 4-AP.
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Affiliation(s)
- H Koyuncuoğlu
- University of Istanbul, Institute for Experimental Medicine (DTAE), Department of Neuroscience, Sehremini, Istanbul, Vakif Guraba Cad. 34280, Turkey.
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15
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Abstract
Evidence from the last several decades indicates that the excitatory amino acid glutamate plays a significant role in nociceptive processing. Glutamate and glutamate receptors are located in areas of the brain, spinal cord and periphery that are involved in pain sensation and transmission. Glutamate acts at several types of receptors, including ionotropic (directly coupled to ion channels) and metabotropic (directly coupled to intracellular second messengers). Ionotropic receptors include those selectively activated by N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid and kainate. Metabotropic glutamate receptors are classified into 3 groups based on sequence homology, signal transduction mechanisms and receptor pharmacology. Glutamate also interacts with the opioid system, and intrathecal or systemic coadministration of glutamate receptor antagonists with opioids may enhance analgesia while reducing the development of opioid tolerance and dependence. The actions of glutamate in the brain seem to be more complex. Activation of glutamate receptors in some brain areas seems to be pronociceptive (e.g. thalamus, trigeminal nucleus), although activation of glutamate receptors in other brain areas seems to be antinociceptive (e.g. periaqueductal grey, ventrolateral medulla). Application of glutamate, or agonists selective for one of the several types of glutamate receptor, to the spinal cord or periphery induces nociceptive behaviours. Inhibition of glutamate release, or of glutamate receptors, in the spinal cord or periphery attenuates both acute and chronic pain in animal models. Similar benefits have been seen in studies involving humans (both patients and volunteers); however, results have been inconsistent. More research is needed to clearly define the role of existing treatment options and explore the possibilities for future drug development.
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Affiliation(s)
- M E Fundytus
- Department of Oncology, McGill University, Montreal, Quebec, Canada.
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16
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Hirata H, Takeshita S, Hu JW, Bereiter DA. Cornea-responsive medullary dorsal horn neurons: modulation by local opioids and projections to thalamus and brain stem. J Neurophysiol 2000; 84:1050-61. [PMID: 10938327 DOI: 10.1152/jn.2000.84.2.1050] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previously, it was determined that microinjection of morphine into the caudal portion of subnucleus caudalis mimicked the facilitatory effects of intravenous morphine on cornea-responsive neurons recorded at the subnucleus interpolaris/caudalis (Vi/Vc) transition region. The aim of the present study was to determine the opioid receptor subtype(s) that mediate modulation of corneal units and to determine whether opioid drugs affected unique classes of units. Pulses of CO(2) gas applied to the cornea were used to excite neurons at the Vi/Vc ("rostral" neurons) and the caudalis/upper cervical spinal cord transition region (Vc/C1, "caudal" neurons) in barbiturate-anesthetized male rats. Microinjection of morphine sulfate (2.9-4.8 nmol) or the selective mu receptor agonist D-Ala, N-Me-Phe, Gly-ol-enkephalin (DAMGO; 1.8-15.0 pmol) into the caudal transition region enhanced the response in 7 of 27 (26%) rostral units to CO(2) pulses and depressed that of 10 units (37%). Microinjection of a selective delta ([D-Pen(2,5)] (DPDPE); 24-30 pmol) or kappa receptor agonist (U50488; 1.8-30.0 pmol) into the caudal transition region did not affect the CO(2)-evoked responses of rostral units. Caudal units were inhibited by local DAMGO or DPDPE but were not affected by U50,488H. The effects of DAMGO and DPDPE were reversed by naloxone (0.2 mg/kg iv). Intravenous morphine altered the CO(2)-evoked activity in a direction opposite to that of local DAMGO in 3 of 15 units, in the same direction as local DAMGO but with greater magnitude in 4 units, and in the same direction with equal magnitude as local DAMGO in 8 units. CO(2)-responsive rostral and caudal units projected to either the thalamic posterior nucleus/zona incerta region (PO/ZI) or the superior salivatory/facial nucleus region (SSN/VII). However, rostral units not responsive to CO(2) pulses projected only to SSN/VII and caudal units not responsive to CO(2) projected only to PO/ZI. It was concluded that the circuitry for opioid analgesia in corneal pain involves multiple sites of action: inhibition of neurons at the caudal transition region, by intersubnuclear connections to modulate rostral units, and by supraspinal sites. Local administration of opioid agonists modulated all classes of corneal units. Corneal stimulus modality was predictive of efferent projection status for rostral and caudal units to sensory thalamus and reflex areas of the brain stem.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Analgesics, Non-Narcotic/pharmacology
- Analgesics, Opioid/pharmacology
- Animals
- Blinking/drug effects
- Blinking/physiology
- Carbon Dioxide/pharmacology
- Cornea/innervation
- Efferent Pathways/physiology
- Electrophysiology
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Enkephalin, D-Penicillamine (2,5)-/pharmacology
- Enkephalins/pharmacology
- Facial Nerve/cytology
- Male
- Medulla Oblongata/cytology
- Medulla Oblongata/drug effects
- Medulla Oblongata/physiology
- Microinjections
- Morphine/pharmacology
- Posterior Horn Cells/physiology
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, mu/agonists
- Stimulation, Chemical
- Thalamus/cytology
- Trigeminal Caudal Nucleus/cytology
- Trigeminal Caudal Nucleus/drug effects
- Trigeminal Caudal Nucleus/physiology
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Affiliation(s)
- H Hirata
- Department of Surgery, Brown University School of Medicine/Rhode Island Hospital, Providence, Rhode Island 02903, USA
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17
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Abstract
Cellular actions of nociceptin/orphanin FQ (N/OFQ) resemble those of micro-, delta-, and kappa-opioids, i.e. activation of inwardly rectifying K(+) conductance, inhibition of high-voltage-activated Ca(2+) channel currents, and impediment of neurotransmitter release. Differences in ORL(1) and micro-receptor distribution lead to: 1) more widespread actions of N/OFQ on periaqueductal gray neurons than opioids and 2) differential effects of N/OFQ and opioids in the brainstem. Also, unlike opioids, N/OFQ inhibits T-type Ca(2+) channel current in sensory neurons. Opioids and N/OFQ may modulate glutamate responses in different ways, and certain actions of N/OFQ are potentiated following nerve injury whereas those of micro-opioids are attenuated. Agonists at ORL(1) receptors may therefore be of clinical interest in the management of neuropathic pain.
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Affiliation(s)
- T D Moran
- Division of Neuroscience and Department of Pharmacology, 9-75 Medical Sciences Building, University of Alberta, T6G 2H7, Edmonton, AB, Canada
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18
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Wang XM, Zhang KM, Long LO, Flores CA, Mokha SS. Endomorphin-1 and endomorphin-2 modulate responses of trigeminal neurons evoked by N-methyl-D-aspartic acid and somatosensory stimuli. J Neurophysiol 2000; 83:3570-4. [PMID: 10848572 DOI: 10.1152/jn.2000.83.6.3570] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study investigated the modulation of N-methyl-D-aspartate (NMDA)-evoked and peripheral cutaneous stimulus-evoked responses of trigeminal neurons by endomorphins, endogenous ligands for the mu-opioid receptor. Effects of endomorphins, administered microiontophoretically, were tested on the responses of nociceptive neurons recorded in the superficial and deeper dorsal horn of the medulla (trigeminal nucleus caudalis) in anesthetized rats. Endomorphin-1 and endomorphin-2 predominantly reduced the NMDA-evoked responses, producing an inhibitory effect of 54.1 +/- 2.96% (mean +/- SE; n = 34, P < 0.001) in 92% (34/37) of neurons and 63.6 +/- 3.61% (n = 32, P < 0.001) in 91% (32/35) of neurons, respectively. The inhibitory effect of endomorphins was modality specific; noxious stimulus-evoked responses were reduced more than nonnoxious stimulus-evoked responses. Naloxone applied at iontophoretic current that blocked the inhibitory effect of [D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-enkephalin, reduced the peak inhibitory effect of endomorphins on the NMDA- and natural stimulus-evoked responses. We suggest that endomorphins by acting at micro-opioid receptor selectively modulate noxious stimulus-evoked responses in the medullary dorsal horn.
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Affiliation(s)
- X M Wang
- Department of Anatomy and Physiology, Meharry Medical College, Nashville, Tennessee 37208, USA
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19
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Sessle BJ. Acute and chronic craniofacial pain: brainstem mechanisms of nociceptive transmission and neuroplasticity, and their clinical correlates. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2000; 11:57-91. [PMID: 10682901 DOI: 10.1177/10454411000110010401] [Citation(s) in RCA: 457] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This paper reviews the recent advances in knowledge of brainstem mechanisms related to craniofacial pain. It also draws attention to their clinical implications, and concludes with a brief overview and suggestions for future research directions. It first describes the general organizational features of the trigeminal brainstem sensory nuclear complex (VBSNC), including its input and output properties and intrinsic characteristics that are commensurate with its strategic role as the major brainstem relay of many types of somatosensory information derived from the face and mouth. The VBSNC plays a crucial role in craniofacial nociceptive transmission, as evidenced by clinical, behavioral, morphological, and electrophysiological data that have been especially derived from studies of the relay of cutaneous nociceptive afferent inputs through the subnucleus caudalis of the VBSNC. The recent literature, however, indicates that some fundamental differences exist in the processing of cutaneous vs. other craniofacial nociceptive inputs to the VBSNC, and that rostral components of the VBSNC may also play important roles in some of these processes. Modulatory mechanisms are also highlighted, including the neurochemical substrate by which nociceptive transmission in the VBSNC can be modulated. In addition, the long-term consequences of peripheral injury and inflammation and, in particular, the neuroplastic changes that can be induced in the VBSNC are emphasized in view of the likely role that central sensitization, as well as peripheral sensitization, can play in acute and chronic pain. The recent findings also provide new insights into craniofacial pain behavior and are particularly relevant to many approaches currently in use for the management of pain and to the development of new diagnostic and therapeutic procedures aimed at manipulating peripheral inputs and central processes underlying nociceptive transmission and its control within the VBSNC.
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Affiliation(s)
- B J Sessle
- Faculty of Dentistry, University of Toronto, Ontario, Canada
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20
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Christensen D, Gautron M, Guilbaud G, Kayser V. Combined systemic administration of the glycine/NMDA receptor antagonist, (+)-HA966 and morphine attenuates pain-related behaviour in a rat model of trigeminal neuropathic pain. Pain 1999; 83:433-440. [PMID: 10568851 DOI: 10.1016/s0304-3959(99)00126-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Chronic constriction injury to the infraorbital nerve (CCI-ION) by loose ligatures may represent a useful model for some trigeminal neuropathic pain disorders. Activation of the N-methyl-D-aspartate (NMDA) receptor is involved in the induction and maintenance of neuropathic pain and may contribute to the poor opioid sensitivity of this syndrome. We evaluated the effect of combined systemic administration of the functional antagonist at the glycine site of the N-methyl-D-aspartate (NMDA) receptor complex, (+)-(1-Hydroxy-3-aminopyrrolodine-2-one) ((+)-HA966) with morphine on mechanical allodynia-like behaviour in CCI-ION rats. Two weeks after surgery rats with a CCI-ION displayed mechanical hyperresponsiveness to von Frey filament stimulation of the vibrissal pad with a median at 0.217 g (95% confidence limits, 0. 217-0.224) versus > or = 12.5 g pre-operative. Administration of either (+)-HA966 (2.5 mg/kg s.c.) alone or morphine (1 mg/kg i.v.) alone was devoid of effects on the mechanical hyperresponsiveness. By contrast, combined administration of (+)-HA966 and morphine (0.25, 0. 5 and 1 mg/kg i.v.) dose-dependently increased the mechanical response thresholds (peak-effects 0.745 g (0.745-0.745), 4.64 (3.3-8. 7) and 12.5 g (8.4-12.5), respectively). This effect was prevented and reversed by naloxone (0.1 mg/kg i.v.). The drug combination produced no motor deficits in animals using the rotarod test. The present results indicate that combination therapy with NMDA/glycine receptor antagonists and morphine may be a useful approach for the clinical management of trigeminal neuropathic pain disorders.
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Affiliation(s)
- Dennis Christensen
- Unité de Recherches de Physiopharmacologie du Système Nerveux, INSERM U-161, 2 rue d'Alésia, 75014 Paris, France
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21
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Mao J. NMDA and opioid receptors: their interactions in antinociception, tolerance and neuroplasticity. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 1999; 30:289-304. [PMID: 10567729 DOI: 10.1016/s0165-0173(99)00020-x] [Citation(s) in RCA: 204] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Over the last several years, significant progress has been made in our understanding of interactions between the N-methyl-D-aspartate (NMDA) and opioid receptors. Such interactions have been demonstrated at two distinct sites: (1) modulation of NMDA receptor-mediated electrophysiological events by opioids; and (2) intracellular events involving interactions between NMDA and opioid receptors. Furthermore, a considerable number of studies have shown the involvement of such interactions in neural mechanisms of nociceptive transmission, antinociception in acute and chronic pain states, opioid tolerance/dependence, and neuroplasticity. Importantly, emerging evidence indicates that activation of NMDA receptors may differentially modulate functions mediated by distinct opioid receptor subtypes, namely mu, delta, and kappa receptors. These studies have greatly enriched our knowledge regarding both NMDA and opioid receptor systems and have shed light on neurobiology of both acute and chronic pain. The advancement of such knowledge also promotes new strategies for better clinical management of pain patients.
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Affiliation(s)
- J Mao
- MGH Pain Center, Massachusetts General Hospital, Harvard Medical School, 15 Parkman Street, Suite WAC-324, Boston, MA, USA
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22
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Chattipakorn SC, Light AR, Willcockson HH, Närhi M, Maixner W. The effect of fentanyl on c-fos expression in the trigeminal brainstem complex produced by pulpal heat stimulation in the ferret. Pain 1999; 82:207-215. [PMID: 10467925 DOI: 10.1016/s0304-3959(99)00046-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have previously shown that Fos-like immunoreactivity (Fos-LI) is evoked in the brainstem of ferrets following stimulation of pulpal A delta and C fibers originating from the maxillary canine. This study evaluated the effects of the mu-opioid receptor agonist fentanyl on Fos expression evoked by noxious thermal stimulation of the right maxillary and mandibular canines in pentobarbital/chloral hydrate anesthetized adult male ferrets. Pulpal heating evoked Fos expression in two distinct regions of the spinal trigeminal nuclear complex: the transitional region between subnucleus interpolaris and caudalis (Vi/Vc) and within the subnucleus caudalis (Vc). More Fos positive cells were expressed in both regions ipsilateral to the site of stimulation compared with the contralateral side (P < 0.05, ANOVA). Pretreatment with fentanyl significantly and dose-dependently suppressed the number of Fos positive cells in both the Vi/Vc transitional region and Vc (P < 0.05, ANOVA). The suppressive effect of fentanyl on Fos expression was blocked by the intravenous administration of naloxone, an opioid antagonist, indicating a specific opioid receptor effect. In addition, opioid receptor antagonism with naloxone alone enhanced Fos expression in Vi/Vc and Vc in response to heat stimulation. The administration of naloxone without heat stimulation failed to evoke Fos expression in Vi/ Vc and Vc. These findings suggest that the activation of trigeminal Vi/Vc and Vc neurons by noxious dental heat stimulation is controlled by a naloxone sensitive endogenous opioid system as indicated by Fos expression. Collectively, these results suggest that neuronal populations in Vi/Vc and Vc regions may contribute to pain responses to noxious dental stimulation and these responses can be modulated by both endogenous and exogenous opioids.
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Affiliation(s)
- Siriporn C Chattipakorn
- Dental Research Center, Room 109, University of North Carolina, Chapel Hill, NC 27599-7455, USA Department of Cell and Molecular Physiology, UNC-Chapel Hill, Chapel Hill, NC 27599-7455, USA Institution of Dentistry, University of Turku, Turku, Finland
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23
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Zhang KM, Wang XM, Peterson AM, Chen WY, Mokha SS. alpha2-adrenoceptors modulate NMDA-evoked responses of neurons in superficial and deeper dorsal horn of the medulla. J Neurophysiol 1998; 80:2210-4. [PMID: 9772273 DOI: 10.1152/jn.1998.80.4.2210] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Extracellular single unit recordings were made from neurons in the superficial and deeper dorsal horn of the medulla (trigeminal nucleus caudalis) in 21 male rats anesthetized with urethan. NMDA produced an antagonist-reversible excitation of 46 nociceptive as well as nonnociceptive neurons. Microiontophoretic application of a preferential alpha2-adrenoceptor (alpha2AR) agonist, (2-[2, 6-dichloroaniline]-2-imidazoline) hydrochloride (clonidine), reduced the NMDA-evoked responses of 86% (6/7) of nociceptive-specific (NS) neurons, 82% (9/11) of wide dynamic range (WDR) neurons, and 67% (4/6) of low-threshold (LT) neurons in the superficial dorsal horn. In the deeper dorsal horn, clonidine inhibited the NMDA-evoked responses of 94% (16/17) of NS and WDR neurons and 60% (3/5) of LT neurons. Clonidine facilitated the NMDA-evoked responses in 14% (1/17) of NS, 9% (1/11) of WDR, and 33% (2/6) of LT neurons in the superficial dorsal horn. Idazoxan, an alpha2AR antagonist, reversed the inhibitory effect of clonidine in 90% (9/10) of neurons, whereas prazosin, an alpha1-adrenoceptor antagonist with affinity for alpha2BAR, and alpha2CAR, were ineffective. We suggest that activation of alpha2ARs produces a predominantly inhibitory modulation of the NMDA-evoked responses of nociceptive neurons in the medullary dorsal horn.
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Affiliation(s)
- K M Zhang
- Department of Anatomy and Physiology, Meharry Medical College, Nashville, Tennessee 37208, USA
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24
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Morphine administered in the substantia gelatinosa of the spinal trigeminal nucleus caudalis inhibits nociceptive activities in the spinal trigeminal nucleus oralis. J Neurosci 1998. [PMID: 9570784 DOI: 10.1523/jneurosci.18-10-03529.1998] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The present study investigates the effects of morphine microinjection into the spinal trigeminal nucleus caudalis (Sp5C) or the spinal trigeminal nucleus oralis (Sp5O) on C-fiber-evoked activities of Sp5O convergent neurons, after supramaximal percutaneous electrical stimulation in halothane-anesthetized rats. When it was microinjected into the Sp5O, morphine (2.5 microg in 0. 25 microl) never depressed the C-fiber-evoked responses of Sp5O convergent neurons (n = 13), whereas these neurons were responsive to the inhibitory effects of systemic morphine (6 mg/kg, i.v.) in a naloxone-reversible manner. On the contrary, morphine microinjected into the Sp5C produced a naloxone-reversible inhibition of the C-fiber-evoked responses of Sp5O neurons (n = 14). The magnitude and the time course of this effect varied according to the location of the injection sites. After microinjection into the superficial laminae (n = 7), a strong depressive effect of morphine (7 +/- 5% of control) on the C-fiber-evoked responses was apparent as soon as 5 min after the injection and could always be reversed by naloxone, administered either intravenously (0.4 mg/kg) or locally (2.5 microg in 0.6 microl) at the same site as morphine. After microinjection into deeper laminae (V-VI), a significant depressive effect (34 +/- 5% of control) of morphine could be detected only 20 min after the injection and was reversed only by intravenous administration of naloxone. These results suggest that morphine exerts its antinociceptive action on Sp5O convergent neurons by blocking the C-fiber inputs that relay in the Sp5C substantia gelatinosa. The mechanisms that underlie the activation of Sp5O convergent neurons by C-fibers and the inhibition of C-fiber-evoked responses of Sp5O convergent neurons by morphine microinjected into the Sp5C are discussed.
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25
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Budai D, Fields HL. Endogenous opioid peptides acting at mu-opioid receptors in the dorsal horn contribute to midbrain modulation of spinal nociceptive neurons. J Neurophysiol 1998; 79:677-87. [PMID: 9463431 DOI: 10.1152/jn.1998.79.2.677] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Activation of neurons in the midbrain periaqueductal gray (PAG) inhibits spinal dorsal horn neurons and produces behavioral antinociception in animals and analgesia in humans. Although dorsal horn regions modulated by PAG activation contain all three opioid receptor classes (mu, delta, and kappa), as well as enkephalinergic interneurons and terminal fields, descending opioid-mediated inhibition of dorsal horn neurons has not been demonstrated. We examined the contribution of dorsal horn mu-opioid receptors to the PAG-elicited descending modulation of nociceptive transmission. Single-unit extracellular recordings were made from rat sacral dorsal horn neurons activated by noxious heating of the tail. Microinjections of bicuculline (BIC) in the ventrolateral PAG led to a 60-80% decrease in the neuronal responses to heat. At the same time, the responses of the same neurons to iontophoretically applied NMDA or kainic acid were not consistently inhibited. The inhibition of heat-evoked responses by PAG BIC was reversed by iontophoretic application of the selective mu-opioid receptor antagonists, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) and D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP). A similar effect was produced by naloxone; however, naloxone had an excitatory influence on dorsal horn neurons in the absence of PAG-evoked descending inhibition. This is the first demonstration that endogenous opioids acting via spinal mu-opioid receptors contribute to brain stem control of nociceptive spinal dorsal horn neurons. The inhibition appears to result in part from presynaptic inhibition of afferents to dorsal horn neurons.
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Affiliation(s)
- D Budai
- Departments of Neurology and Physiology and the W. M. Keck Foundation Center for Integrative Neuroscience, University of California, San Francisco, California 94143-0114, USA
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26
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Abstract
This paper is the nineteenth installment of our annual review of research concerning the opiate system. It summarizes papers published during 1996 reporting the behavioral effects of the opiate peptides and antagonists, excluding the purely analgesic effects, although stress-induced analgesia is included. The specific topics covered this year include stress, tolerance and dependence; eating; drinking; gastrointestinal, renal, and hepatic function; mental illness and mood; learning, memory, and reward; cardiovascular responses; respiration and thermoregulation; seizures and other neurological disorders; electrical-related activity; general activity and locomotion; sex, pregnancy, and development; immunological responses; and other behaviors.
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Affiliation(s)
- G A Olson
- Department of Psychology, University of New Orleans, LA 70148, USA
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27
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Wang XM, Yan JQ, Zhang KM, Mokha SS. Role of opioid receptors (mu, delta 1, delta 2) in modulating responses of nociceptive neurons in the superficial and deeper dorsal horn of the medulla (trigeminal nucleus caudalis) in the rat. Brain Res 1996; 739:235-43. [PMID: 8955943 DOI: 10.1016/s0006-8993(96)00828-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This report describes the effects of intravenously administered agonists and antagonists at mu-, delta 1- and delta 2-opioid receptors on the A delta- and C-fiber-evoked responses of trigeminal nociceptive neurons in anesthetized rats. Extracellular single unit recordings were made from 61 nociceptive neurons (23 NS, 38 WDR) in the superficial and 37 nociceptive neurons (3 NS, 34 WDR) in the deeper dorsal horn of the medulla (trigeminal nucleus caudalis). Administration of either the delta 1-receptor agonist [D-Pen2,5]enkephalin (DPDPE; 0.05-2 mg/kg), the delta 2-receptor agonist [D-Ala2, Glu4]deltorphin (DELT; 1-2 mg/kg) or the mu-receptor agonist [D-Ala2, N-MePhe4, Gly5-ol]enkephalin (DAMGO; 0.05-1 mg/kg) inhibited the A delta- and C-fiber-evoked responses of nociceptive neurons in the superficial and deeper dorsal horn. The inhibitory effect was more pronounced on the C-fiber-evoked responses than on the A delta-fiber-evoked responses. In other neurons, DPDPE also produced facilitation, or inhibition followed by facilitation, or differential effects (inhibition of the C-fiber-evoked responses and facilitation of the A delta-fiber-evoked responses) on the A delta- and C-fiber-evoked responses. The effects of DPDPE were antagonized by 7-benzylidenenaltrexone (BNTX, 0.4-1 mg/kg), a delta 1-receptor antagonist, in 88% (7/8) of neurons. Naltriben (NTB, 0.7-1 mg/kg), a delta 2-receptor antagonist, antagonized the effect of both DELT and DPDPE. A smaller dose of NTB (0.3 mg/kg), which failed to reverse the effects of DPDPE in 100% (4/4) of neurons, effectively antagonized the effects of DELT in 100% (6/6) of neurons. The inhibitory action of DAMGO was completely antagonized by naloxone (0.2 mg/kg) in 100% (6/6) of neurons. The results of the present investigation suggest that: (1) mu-, delta 1- and delta 2-opioid receptors play an important role in the inhibitory modulation of the A delta- and C-fiber-evoked responses of nociceptive neurons in the superficial and deeper dorsal horn of the medulla; (2) selective inhibition of the C-fiber-evoked responses by activation of opioid receptors may account for the opioid-mediated selective suppression of second or persistent pain as compared to first pain; and (3) NTB, in a limited dose range, can discriminate between delta 1- and delta 2-opioid receptor subtypes.
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MESH Headings
- Animals
- Benzylidene Compounds/pharmacology
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
- Enkephalin, D-Penicillamine (2,5)-
- Enkephalins/pharmacology
- Evoked Potentials/drug effects
- Male
- Naloxone/pharmacology
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Narcotic Antagonists/pharmacology
- Nerve Fibers/drug effects
- Nerve Fibers/physiology
- Neurons/drug effects
- Neurons/physiology
- Nociceptors/drug effects
- Nociceptors/physiology
- Oligopeptides/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/physiology
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/physiology
- Trigeminal Caudal Nucleus/cytology
- Trigeminal Caudal Nucleus/drug effects
- Trigeminal Caudal Nucleus/physiology
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Affiliation(s)
- X M Wang
- Department of Physiology, Meharry Medical College, Nashville, TN 37208, USA
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