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Hsieh MC, Lai CY, Yeh CM, Yang PS, Cheng JK, Wang HH, Lin KH, Nie ST, Lin TB, Peng HY. Phosphorylated Upstream Frameshift 1-dependent Nonsense-mediated μ-Opioid Receptor mRNA Decay in the Spinal Cord Contributes to the Development of Neuropathic Allodynia-like Behavior in Rats. Anesthesiology 2023; 138:634-655. [PMID: 36867667 DOI: 10.1097/aln.0000000000004550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
BACKGROUND Nonsense-mediated messenger RNA (mRNA) decay increases targeted mRNA degradation and has been implicated in the regulation of gene expression in neurons. The authors hypothesized that nonsense-mediated μ-opioid receptor mRNA decay in the spinal cord is involved in the development of neuropathic allodynia-like behavior in rats. METHODS Adult Sprague-Dawley rats of both sexes received spinal nerve ligation to induce neuropathic allodynia-like behavior. The mRNA and protein expression contents in the dorsal horn of animals were measured by biochemical analyses. Nociceptive behaviors were evaluated by the von Frey test and the burrow test. RESULTS On Day 7, spinal nerve ligation significantly increased phosphorylated upstream frameshift 1 (UPF1) expression in the dorsal horn (mean ± SD; 0.34 ± 0.19 in the sham ipsilateral group vs. 0.88 ± 0.15 in the nerve ligation ipsilateral group; P < 0.001; data in arbitrary units) and drove allodynia-like behaviors in rats (10.58 ± 1.72 g in the sham ipsilateral group vs. 1.19 ± 0.31 g in the nerve ligation ipsilateral group, P < 0.001). No sex-based differences were found in either Western blotting or behavior tests in rats. Eukaryotic translation initiation factor 4A3 (eIF4A3) triggered SMG1 kinase (0.06 ± 0.02 in the sham group vs. 0.20 ± 0.08 in the nerve ligation group, P = 0.005, data in arbitrary units)-mediated UPF1 phosphorylation, leading to increased nonsense-mediated mRNA decay factor SMG7 binding and µ-opioid receptor mRNA degradation (0.87 ± 0.11-fold in the sham group vs. 0.50 ± 0.11-fold in the nerve ligation group, P = 0.002) in the dorsal horn of the spinal cord after spinal nerve ligation. Pharmacologic or genetic inhibition of this signaling pathway in vivo ameliorated allodynia-like behaviors after spinal nerve ligation. CONCLUSIONS This study suggests that phosphorylated UPF1-dependent nonsense-mediated μ-opioid receptor mRNA decay is involved in the pathogenesis of neuropathic pain. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Ming-Chun Hsieh
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan
| | - Cheng-Yuan Lai
- Institute of Biomedical Sciences, MacKay Medical College, New Taipei City, Taiwan
| | - Chou-Ming Yeh
- Division of Thoracic Surgery, Department of Health, Taichung Hospital, Executive Yuan, Taichung, Taiwan; Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Po-Sheng Yang
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan; Department of Surgery, Mackay Memorial Hospital, Taipei, Taiwan
| | - Jen-Kun Cheng
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan; Department of Anesthesiology, Mackay Memorial Hospital, Taipei, Taiwan
| | - Hsueh-Hsiao Wang
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan
| | - Kuan-Hung Lin
- Institute of Biomedical Sciences, MacKay Medical College, New Taipei City, Taiwan; Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Siao-Tong Nie
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan
| | - Tzer-Bin Lin
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan; Institute of New Drug Development, College of Medicine, China Medical University, Taichung, Taiwan
| | - Hsien-Yu Peng
- Department of Medicine, Mackay Medical College, New Taipei, Taiwan; Institute of Biomedical Sciences, MacKay Medical College, New Taipei City, Taiwan
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2
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Tan LL, Kuner R. Neocortical circuits in pain and pain relief. Nat Rev Neurosci 2021; 22:458-471. [PMID: 34127843 DOI: 10.1038/s41583-021-00468-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2021] [Indexed: 02/07/2023]
Abstract
The sensory, associative and limbic neocortical structures play a critical role in shaping incoming noxious inputs to generate variable pain perceptions. Technological advances in tracing circuitry and interrogation of pathways and complex behaviours are now yielding critical knowledge of neocortical circuits, cellular contributions and causal relationships between pain perception and its abnormalities in chronic pain. Emerging insights into neocortical pain processing suggest the existence of neocortical causality and specificity for pain at the level of subdomains, circuits and cellular entities and the activity patterns they encode. These mechanisms provide opportunities for therapeutic intervention for improved pain management.
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Affiliation(s)
- Linette Liqi Tan
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.
| | - Rohini Kuner
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.
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Huang J, Zhang Z, Gambeta E, Chen L, Zamponi GW. An orbitofrontal cortex to midbrain projection modulates hypersensitivity after peripheral nerve injury. Cell Rep 2021; 35:109033. [PMID: 33910011 DOI: 10.1016/j.celrep.2021.109033] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 02/01/2021] [Accepted: 04/02/2021] [Indexed: 12/28/2022] Open
Abstract
Neuropathic pain is a debilitating condition that is often refractory to treatment. The network of neural substrates for pain transmission and control within the brain is complex and remains poorly understood. Through a combination of neuronal tracing, optogenetics, chemogenetics, electrophysiological recordings, and behavioral assessment, we demonstrate that activation of layer 5 pyramidal neurons in the ventrolateral orbitofrontal cortex (vlOFC) attenuates mechanical and thermal hypersensitivity and cold allodynia in mice with neuropathic pain induced by spared nerve injury (SNI). These vlOFC output neurons project to the posterior ventrolateral periaqueductal gray (vlPAG) region and receive inputs from the ventromedial thalamus (VM). Specific optogenetic and chemogenetic activation of the vlOFC-vlPAG and the VM-vlOFC circuits inhibits hypersensitivity associated with neuropathy. Thus, we reveal a modulatory role of the vlOFC and its projections to the vlPAG circuit in the processing of hypersensitive nociception.
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Affiliation(s)
- Junting Huang
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China; Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Zizhen Zhang
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Eder Gambeta
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Lina Chen
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada.
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Wu Y, Fu D, Gu Q, Li Y, Qian Z, Han J, Liu Z, Ren W, Liu Y. Activation of CB1 receptors on GABAergic interneurons in the ventrolateral orbital cortex induces analgesia. Neurosci Lett 2020; 736:135286. [PMID: 32745558 DOI: 10.1016/j.neulet.2020.135286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 07/14/2020] [Accepted: 07/29/2020] [Indexed: 10/23/2022]
Abstract
The prefrontal ventrolateral orbital cortex (VLO) is involved in antinociception. It has been found that dopamine receptors, adrenoceptors, serotonin receptors and μ-opioid receptors are involved in this effect through direct/indirect activation of the VLO output neurons. However, the effect of CB1 receptors on the VLO modulation of pain has not been studied. In this study, we investigated whether activation of CB1 receptors in the VLO modulates nociception. A common peroneal nerve (CPN) ligation model was used to induce neuropathic pain in male mice. On day 13 after CPN ligation, spontaneous firing of the VLO pyramidal neurons was recorded and CB1 receptor level in the VLO was detected. Mechanical allodynia was measured after HU210 was microinjected into the VLO. Relative contribution of CB1 receptors on GABAergic neurons and glutamatergic neurons was determined by CB1 receptor knockdown using a viral strategy. Our data indicated that on day 13 after nerve injury, spontaneous firing of the VLO pyramidal neurons reduced significantly but was enhanced by intraperitoneal injection of HU210 (20 μg/kg), a potent CB1 receptor agonist. Expression of CB1 receptor in the VLO was up-regulated. Microinjection of HU210 into the VLO attenuated allodynia, and this effect was blocked by pre-microinjection of specific CB1 receptor antagonist AM281. Deletion of CB1 receptors on GABAergic neurons in the VLO can completely block HU210-induced analgesia. Thus, it can be concluded that activation of CB1 receptors on GABAergic interneurons in the VLO may be involved in analgesia effect of cannabinoids.
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Affiliation(s)
- Yuwei Wu
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
| | - Dongqin Fu
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
| | - Qiaofen Gu
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
| | - Yongfeng Li
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
| | - Zhaoqiang Qian
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
| | - Jing Han
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
| | - Zhiqiang Liu
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
| | - Wei Ren
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China
| | - Yihui Liu
- MOE Key Laboratory of Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, 199 South Chang'an Road, Xi'an 710062, China.
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Genaro K, Fabris D, Prado WA. The antinociceptive effect of anterior pretectal nucleus stimulation is mediated by distinct neurotransmitter mechanisms in descending pain pathways. Brain Res Bull 2019; 146:164-170. [DOI: 10.1016/j.brainresbull.2019.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/14/2018] [Accepted: 01/03/2019] [Indexed: 01/05/2023]
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6
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Ventrolateral orbital cortex oxytocin attenuates neuropathic pain through periaqueductal gray opioid receptor. Pharmacol Rep 2018; 70:577-583. [DOI: 10.1016/j.pharep.2017.12.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 12/13/2017] [Accepted: 12/20/2017] [Indexed: 11/18/2022]
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7
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Individual differences in initial morphine sensitivity as a predictor for the development of opiate addiction in rats. Behav Brain Res 2016; 313:315-323. [DOI: 10.1016/j.bbr.2016.07.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 07/09/2016] [Accepted: 07/21/2016] [Indexed: 12/14/2022]
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8
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Liu L, Ma SH, Xia LJ. The influence of thiamin on the efficacy of pregabalin in rats with spinal nerve ligation (SNL)-induced neuropathic pain. Neurol Res 2016; 38:717-24. [PMID: 27334563 DOI: 10.1080/01616412.2016.1188550] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The thiamin is often used in the treatment of neuropathy, and pregabalin is often used to treat neuropathic pain. Our study examined the influence of thiamin on the efficacy of pregabalin in a rat model of spinal nerve ligation (SNL)-induced neuropathic pain. METHODS Sprague-Dawley male rats were randomly divided into six groups. The neuropathic pain-relieving properties were measured by plantar test, cold plate test, and hot plate test after administration of pregabalin (i.v) and/or thiamin (i.p) in SNL rats 14 days after operation. RESULTS In the therapy period, pregabalin, or thiamin alone all produced antinociceptive effects in rats with neuropathic pain. And combination treatment of thiamin and pregabalin resulted in an enhanced pain relief compared to the administration of pregabalin or thiamin alone. CONCLUSION Combination of thiamin and pregabalin produces an additive antinociceptive effect in neuropathic pain rats, this drug combination may offer a beneficial treatment option for neuropathic pain.
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Affiliation(s)
- Lin Liu
- a Department of Pain , Henan Province Hospital , Zhengzhou , China
| | - Song-He Ma
- a Department of Pain , Henan Province Hospital , Zhengzhou , China
| | - Ling-Jie Xia
- a Department of Pain , Henan Province Hospital , Zhengzhou , China
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9
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The role of nicotinic acetylcholine and opioid systems of the ventral orbital cortex in modulation of formalin-induced orofacial pain in rats. Eur J Pharmacol 2015; 758:147-52. [DOI: 10.1016/j.ejphar.2015.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 03/30/2015] [Accepted: 04/02/2015] [Indexed: 12/16/2022]
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10
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Zhu JX, Xu FY, Xu WJ, Zhao Y, Qu CL, Tang JS, Barry DM, Du JQ, Huo FQ. The role of α₂ adrenoceptor in mediating noradrenaline action in the ventrolateral orbital cortex on allodynia following spared nerve injury. Exp Neurol 2013; 248:381-6. [PMID: 23872512 DOI: 10.1016/j.expneurol.2013.07.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 07/05/2013] [Accepted: 07/11/2013] [Indexed: 10/26/2022]
Abstract
The present study examined the role of α₂ adrenoceptor in mediating noradrenaline action in the ventrolateral orbital cortex (VLO) on allodynia induced by spared nerve injury (SNI) in the rat. The mechanical paw withdrawal threshold (PWT) was measured using von-Frey filaments. Microinjection of noradrenaline (1, 2, 4 μg in 0.5 μl) into the VLO, contralateral to the site of nerve injury, reduced allodynia; PWT increased in a dose-dependent manner. Similar to noradrenaline, microinjection of selective α₂ adrenoceptor agonist clonidine into the same VLO site also reduced allodynia, and was blocked by selective α₂ adrenoceptor antagonist yohimbine. Furthermore, administration of γ-aminobutyric acid A (GABAA) receptor antagonist bicuculline or picrotoxin to the VLO significantly enhanced clonidine-induced inhibition of allodynia, while GABAA receptor agonist muscimol or THIP (2,5,6,7-retrahydroisoxazolo(5,4-c)pyridine-3-ol hydrochloride) attenuated clonidine-induced inhibition. These results suggest that noradrenaline acting in the VLO can potentially reduce allodynia induced by SNI, and this effect is mediated by α₂ adrenoceptor. Moreover, GABAergic disinhibition may participate in α₂ receptor mediating effects in neuropathic pain in the central nervous system.
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Affiliation(s)
- Juan-Xia Zhu
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University College of Medicine, Yanta Road W. 76#, Xi'an, Shaanxi 710061, PR China; Department of Physiology, Xi'an Medical University, Xinwang Road 1#, Xi'an, Shaanxi 710021, PR China
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Pais-Vieira M, Aguiar P, Lima D, Galhardo V. Inflammatory pain disrupts the orbitofrontal neuronal activity and risk-assessment performance in a rodent decision-making task. Pain 2012; 153:1625-1635. [DOI: 10.1016/j.pain.2012.04.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 04/10/2012] [Accepted: 04/10/2012] [Indexed: 11/28/2022]
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12
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Hahm ET, Kim Y, Lee JJ, Cho YW. GABAergic synaptic response and its opioidergic modulation in periaqueductal gray neurons of rats with neuropathic pain. BMC Neurosci 2011; 12:41. [PMID: 21569381 PMCID: PMC3103474 DOI: 10.1186/1471-2202-12-41] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 05/12/2011] [Indexed: 11/10/2022] Open
Abstract
Background Neuropathic pain is a chronic and intractable symptom associated with nerve injury. The periaqueductal gray (PAG) is important in the endogenous pain control system and is the main site of the opioidergic analgesia. To investigate whether neuropathic pain affects the endogenous pain control system, we examined the effect of neuropathic pain induced by sacral nerve transection on presynaptic GABA release, the kinetics of postsynaptic GABA-activated Cl- currents, and the modulatory effect of μ-opioid receptor (MOR) activation in mechanically isolated PAG neurons with functioning synaptic boutons. Results In normal rats, MOR activation inhibited the frequency of GABAergic miniature inhibitory postsynaptic currents (mIPSCs) to 81.3% of the control without any alteration in their amplitude. In neuropathic rats, the inhibition of mIPSC frequency by MOR activation was 82.4%. The frequency of GABAergic mIPSCs in neuropathic rats was 151.8% of normal rats without any difference in the mIPSC amplitude. Analysis of mIPSC kinetics showed that the fast decay time constant and synaptic charge transfer of mIPSCs in neuropathic rats were 76.0% and 73.2% of normal rats, respectively. Conclusions These results indicate that although the inhibitory effect of MOR activation on presynaptic GABA release is similar in both neuropathic and normal rats, neuropathic pain may inhibit endogenous analgesia in the PAG through an increase in presynaptic GABA release.
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Affiliation(s)
- Eu-Teum Hahm
- Department of Physiology, Biomedical Science Institute, Kyung Hee University School of Medicine, Seoul 130-701, South Korea
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13
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Tang JS, Qu CL, Huo FQ. The thalamic nucleus submedius and ventrolateral orbital cortex are involved in nociceptive modulation: A novel pain modulation pathway. Prog Neurobiol 2009; 89:383-9. [DOI: 10.1016/j.pneurobio.2009.10.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2009] [Revised: 09/27/2009] [Accepted: 10/01/2009] [Indexed: 12/01/2022]
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14
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The impact of age on emotional and cognitive behaviours triggered by experimental neuropathy in rats. Pain 2009; 144:57-65. [DOI: 10.1016/j.pain.2009.02.024] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/13/2009] [Accepted: 02/23/2009] [Indexed: 01/06/2023]
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Abstract
Pain is a complex experience encompassing sensory-discriminative, affective-motivational and cognitiv e-emotional components mediated by different mechanisms. Contrary to the traditional view that the cerebral cortex is not involved in pain perception, an extensive cortical network associated with pain processing has been revealed using multiple methods over the past decades. This network consistently includes, at least, the anterior cingulate cortex, the agranular insular cortex, the primary (SI) and secondary somatosensory (SII) cortices, the ventrolateral orbital cortex and the motor cortex. These cortical structures constitute the medial and lateral pain systems, the nucleus submedius-ventrolateral orbital cortex-periaqueductal gray system and motor cortex system, respectively. Multiple neurotransmitters, including opioid, glutamate, GABA and dopamine, are involved in the modulation of pain by these cortical structures. In addition, glial cells may also be involved in cortical modulation of pain and serve as one target for pain management research. This review discusses recent studies of pain modulation by these cerebral cortical structures in animals and human.
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Koda Y, Del Borgo M, Wessling ST, Lazarus LH, Okada Y, Toth I, Blanchfield JT. Synthesis and in vitro evaluation of a library of modified endomorphin 1 peptides. Bioorg Med Chem 2008; 16:6286-96. [PMID: 18468445 DOI: 10.1016/j.bmc.2008.04.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 04/07/2008] [Accepted: 04/10/2008] [Indexed: 10/22/2022]
Abstract
Endomorphin 1 (Endo-1=Tyr-Pro-Trp-Phe-NH(2)), an endogenous opioid with high affinity and selectivity for mu-opioid receptors, mediates acute and neuropathic pain in rodents. To overcome metabolic instability and poor membrane permeability, the N- and C-termini of Endo-1 were modified by lipoamino acids (Laa) and/or sugars, and 2',6'-dimethyltyrosine (Dmt) replacement of Tyr. Analogues were assessed for mu-opioid receptor affinity, inhibition of cAMP accumulation, enzymatic stability, and permeability across Caco-2 cell monolayers. C-terminus modification decreased receptor affinity, while N-terminus C8-Laa improved stability and permeability with slight change in receptor affinity. Dmt provided a promising lead compound: [C8Laa-Dmt[1]]-Endo-1 is nine times more stable (t(1/2)=43.5min), >8-fold more permeable in Caco-2 cell monolayers, and exhibits 140-fold greater mu-opioid receptor affinity (K(imu)=0.08nM).
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Affiliation(s)
- Yasuko Koda
- School of Pharmacy, University of Queensland, St. Lucia, Brisbane, Qld 4072, Australia
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Abstract
This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, United States.
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18
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Current World Literature. Curr Opin Anaesthesiol 2007; 20:388-94. [PMID: 17620851 DOI: 10.1097/aco.0b013e3282c3a878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Zhao M, Wang JY, Jia H, Tang JS. Roles of different subtypes of opioid receptors in mediating the ventrolateral orbital cortex opioid-induced inhibition of mirror-neuropathic pain in the rat. Neuroscience 2007; 144:1486-94. [PMID: 17184926 DOI: 10.1016/j.neuroscience.2006.11.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 11/07/2006] [Accepted: 11/08/2006] [Indexed: 11/26/2022]
Abstract
Previous studies have demonstrated that opioid receptors in the prefrontal ventrolateral orbital cortex (VLO) are involved in anti-nociception. The aim of this current study was to examine whether opioid receptors in the VLO have effects on the hypersensitivity induced by contralateral L5 and L6 spinal nerve ligation (SNL), termed as mirror neuropathic pain (MNP) in the male rat. Morphine (1.0, 2.5, 5.0 microg) microinjected into the VLO contralateral to the SNL depressed the mechanical paw withdrawal assessed by von Frey filaments and the cold plate (4 degrees C)-induced paw lifting in a dose-dependent manner on the side without SNL. These effects were antagonized by microinjection of the non-selective opioid receptor antagonist naloxone (1.0 mug) into the same VLO site. Microinjection of endomorphin-1 (5.0 microg), a highly selective mu-opioid receptor agonist, and [d-Ala(2), d-Leu(5)]-enkephalin (DADLE, 10 microg), a delta-/mu-receptor agonist, also depressed the MNP. The effects of both drugs were blocked by selective mu-receptor antagonist beta-funaltrexamine (beta-FNA, 3.75 microg), but the effect of the DADLE was not influenced by the selective delta-receptor antagonist naltrindole (5.0 microg). Microinjection of the kappa-opioid receptor agonist spiradoline mesylate salt (U-62066) (100 microg) had no effect on the MNP. These results suggest that the VLO is involved in opioid-induced inhibition of the MNP and the effect is mediated by mu- (but not delta- and kappa-) opioid receptors.
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MESH Headings
- Afferent Pathways/drug effects
- Afferent Pathways/metabolism
- Analgesics, Opioid/pharmacology
- Animals
- Functional Laterality
- Hyperalgesia/drug therapy
- Hyperalgesia/metabolism
- Hyperalgesia/physiopathology
- Ligation
- Male
- Morphine/pharmacology
- Narcotic Antagonists/pharmacology
- Nociceptors/drug effects
- Nociceptors/metabolism
- Pain Measurement
- Pain Threshold/drug effects
- Pain Threshold/physiology
- Peripheral Nervous System Diseases/drug therapy
- Peripheral Nervous System Diseases/metabolism
- Peripheral Nervous System Diseases/physiopathology
- Prefrontal Cortex/drug effects
- Prefrontal Cortex/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/metabolism
- Spinal Nerves/injuries
- Spinal Nerves/physiopathology
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Affiliation(s)
- M Zhao
- Department of Physiology and Pathophysiology, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an Jiaotong University School of Medicine, Yanta Road West 76, Xi'an, Shaanxi 710061, PR China
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