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Montigné E, Balayssac D. Exploring Cholinergic Compounds for Peripheral Neuropathic Pain Management: A Comprehensive Scoping Review of Rodent Model Studies. Pharmaceuticals (Basel) 2023; 16:1363. [PMID: 37895835 PMCID: PMC10609809 DOI: 10.3390/ph16101363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/01/2023] [Accepted: 09/14/2023] [Indexed: 10/29/2023] Open
Abstract
Neuropathic pain affects about 7-8% of the population, and its management still poses challenges with unmet needs. Over the past decades, researchers have explored the cholinergic system (muscarinic and nicotinic acetylcholine receptors: mAChR and nAChR) and compounds targeting these receptors as potential analgesics for neuropathic pain management. This scoping review aims to provide an overview of studies on peripheral neuropathic pain (PNP) in rodent models, exploring compounds targeting cholinergic neurotransmission. The inclusion criteria were original articles on PNP in rodent models that explored the use of compounds directly targeting cholinergic neurotransmission and reported results of nociceptive behavioral assays. The literature search was performed in the PubMed and Web of Science databases (1 January 2000-22 April 2023). The selection process yielded 82 publications, encompassing 62 compounds. The most studied compounds were agonists of α4β2 nAChR and α7 nAChR, and antagonists of α9/α10 nAChR, along with those increasing acetylcholine and targeting mAChRs. Studies mainly reported antinociceptive effects in traumatic PNP models, and to a lesser extent, chemotherapy-induced neuropathy or diabetic models. These preclinical studies underscore the considerable potential of cholinergic compounds in the management of PNP, warranting the initiation of clinical trials.
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Affiliation(s)
- Edouard Montigné
- INSERM, U1107, NEURO-DOL, Université Clermont Auvergne, F-63000 Clermont-Ferrand, France;
| | - David Balayssac
- INSERM, U1107, NEURO-DOL, Université Clermont Auvergne, Direction de la Recherche Clinique et de l’Innovation, CHU Clermont-Ferrand, F-63000 Clermont-Ferrand, France
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Jareczek FJ, White SR, Hammond DL. Plasticity in Brainstem Mechanisms of Pain Modulation by Nicotinic Acetylcholine Receptors in the Rat. eNeuro 2017; 4:ENEURO.0364-16.2017. [PMID: 28197544 PMCID: PMC5286660 DOI: 10.1523/eneuro.0364-16.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 01/03/2023] Open
Abstract
Individuals with chronic pain may be driven to smoke more because the analgesic efficacy of nicotine diminishes. To determine whether persistent pain diminishes the actions of a nicotinic acetylcholine receptor (nAChR) agonist in pain modulatory pathways, we examined the effects of epibatidine in the rostral ventromedial medulla (RVM) of rats with and without inflammatory injury induced by intraplantar injection of complete Freund's adjuvant (CFA). In uninjured rats, epibatidine produced a dose-dependent antinociception that was completely blocked by dihydro-β-erythroidine (DHβE; α4β2 antagonist) and partially blocked by methyllycaconitine (MLA; α7 antagonist). Epibatidine reversed heat hyperalgesia when microinjected in the RVM 4 h, 4 d, or 2 weeks after CFA treatment. Although DHβE completely blocked epibatidine's antihyperalgesic effect at 4 h, at 2 weeks it elicited only partial antagonism. Methyllycaconitine was ineffective at both time points. Epibatidine's antinociceptive efficacy in the uninjured hind paw progressively declined, and it was without effect 2 weeks after CFA. Moreover, as early as 4 h after CFA, the antinociceptive effect of epibatidine was no longer antagonized by DHβE. Neither antagonist alone altered paw withdrawal latency in uninjured or CFA-treated rats, suggesting that neither α4β2 nor α7 nAChRs are tonically active in the RVM. The Bmax and Kd of α4β2 nAChRs in the RVM were unchanged after CFA treatment. These observations provide the first evidence of pharmacological plasticity of the actions of α4β2 nAChR agonists in a critical brainstem pain modulatory pathway and may in part explain why people with chronic pain smoke more than the general population.
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Affiliation(s)
- Francis J. Jareczek
- Medical Scientist Training Program, University of Iowa, Iowa City, IA 52242
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242
| | | | - Donna L. Hammond
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242
- Department of Anesthesia, University of Iowa, Iowa City, IA 52242
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242
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Wu S, Marie Lutz B, Miao X, Liang L, Mo K, Chang YJ, Du P, Soteropoulos P, Tian B, Kaufman AG, Bekker A, Hu Y, Tao YX. Dorsal root ganglion transcriptome analysis following peripheral nerve injury in mice. Mol Pain 2016; 12:12/0/1744806916629048. [PMID: 27030721 PMCID: PMC4955972 DOI: 10.1177/1744806916629048] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/30/2015] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Peripheral nerve injury leads to changes in gene expression in primary sensory neurons of the injured dorsal root ganglia. These changes are believed to be involved in neuropathic pain genesis. Previously, these changes have been identified using gene microarrays or next generation RNA sequencing with poly-A tail selection, but these approaches cannot provide a more thorough analysis of gene expression alterations after nerve injury. METHODS The present study chose to eliminate mRNA poly-A tail selection and perform strand-specific next generation RNA sequencing to analyze whole transcriptomes in the injured dorsal root ganglia following spinal nerve ligation. Quantitative real-time reverse transcriptase polymerase chain reaction assay was carried out to verify the changes of some differentially expressed RNAs in the injured dorsal root ganglia after spinal nerve ligation. RESULTS Our results showed that more than 50 million (M) paired mapped sequences with strand information were yielded in each group (51.87 M-56.12 M in sham vs. 51.08 M-57.99 M in spinal nerve ligation). Six days after spinal nerve ligation, expression levels of 11,163 out of a total of 27,463 identified genes in the injured dorsal root ganglia significantly changed, of which 52.14% were upregulated and 47.86% downregulated. The largest transcriptional changes were observed in protein-coding genes (91.5%) followed by noncoding RNAs. Within 944 differentially expressed noncoding RNAs, the most significant changes were seen in long interspersed noncoding RNAs followed by antisense RNAs, processed transcripts, and pseudogenes. We observed a notable proportion of reads aligning to intronic regions in both groups (44.0% in sham vs. 49.6% in spinal nerve ligation). Using quantitative real-time polymerase chain reaction, we confirmed consistent differential expression of selected genes including Kcna2, Oprm1 as well as lncRNAs Gm21781 and 4732491K20Rik following spinal nerve ligation. CONCLUSION Our findings suggest that next generation RNA sequencing can be used as a promising approach to analyze the changes of whole transcriptomes in dorsal root ganglia following nerve injury and to possibly identify new targets for prevention and treatment of neuropathic pain.
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Affiliation(s)
- Shaogen Wu
- Department of Obstetrics and Gynecology, Nanjing Drum Tower Hospital, Nanjing University Medical School, Jiangsu, China Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Brianna Marie Lutz
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Xuerong Miao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA Department of Anesthesiology and Intensive Care, Eastern Hepatobiliary Surgical Hospital, The Second Military Medical University, Shanghai, China
| | - Lingli Liang
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Kai Mo
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yun-Juan Chang
- High Performance and Research Computing, Office of Information Technology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Peicheng Du
- High Performance and Research Computing, Office of Information Technology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Patricia Soteropoulos
- Departments of Biochemistry & Microbiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Bin Tian
- Departments of Biochemistry & Microbiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Andrew G Kaufman
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Alex Bekker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Yali Hu
- Department of Obstetrics and Gynecology, Nanjing Drum Tower Hospital, Nanjing University Medical School, Jiangsu, China
| | - Yuan-Xiang Tao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA Departments of Cell Biology & Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA Department of Pharmacology & Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
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Freitas KC, Carroll FI, Negus SS. Effects of nicotinic acetylcholine receptor agonists in assays of acute pain-stimulated and pain-depressed behaviors in rats. J Pharmacol Exp Ther 2016; 355:341-50. [PMID: 26359313 DOI: 10.1124/jpet.115.226803] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Agonists at nicotinic acetylcholine receptors (nAChRs) constitute one drug class being evaluated as candidate analgesics. Previous preclinical studies have implicated α4β2 and α7 nAChRs as potential mediators of the antinociceptive effects of (–)-nicotine hydrogen tartrate (nicotine) and other nAChR agonists; however, these studies have relied exclusively on measures of pain-stimulated behavior, which can be defined as behaviors that increase in frequency, rate, or intensity after presentation of a noxious stimulus. Pain is also associated with depression of many behaviors, and drug effects can differ in assays of pain-stimulated versus pain-depressed behavior. Accordingly, this study compared the effects of nicotine, the selective α4/6β2 agonist 5-(123I)iodo-3-[2(S)-2-azetidinylmethoxy]pyridine (5-I-A-85380), and the selective α7 agonist N-(3R)-1-azabicyclo(2.2.2)oct-3-yl-4-chlorobenzamide in assays of pain-stimulated and pain-depressed behavior in male Sprague-Dawley rats. Intraperitoneal injection of dilute lactic acid served as an acute noxious stimulus to either stimulate a stretching response or depress the operant responding, which is maintained by electrical brain stimulation in an intracranial self-stimulation (ICSS) procedure. Nicotine produced a dose-dependent, time-dependent, and mecamylamine-reversible blockade of both acid-stimulated stretching and acid-induced depression of ICSS. 5-I-A-85380 also blocked both acid-stimulated stretching and acid-induced depression of ICSS, whereas N-(3R)-1-azabicyclo(2.2.2)oct-3-yl-4-chlorobenzamide produced no effect in either procedure. Both nicotine and 5-I-A-85380 were ≥10-fold more potent in blocking the acid-induced depression of ICSS than in blocking the acid-induced stimulation of stretching. These results suggest that stimulation of α4β2 and/or α6β2 nAChRs may be especially effective to alleviate the signs of pain-related behavioral depression in rats; however, nonselective behavioral effects may contribute to apparent antinociception.
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Affiliation(s)
- Kelen C Freitas
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia
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Bagdas D, AlSharari SD, Freitas K, Tracy M, Damaj MI. The role of alpha5 nicotinic acetylcholine receptors in mouse models of chronic inflammatory and neuropathic pain. Biochem Pharmacol 2015; 97:590-600. [PMID: 25931144 DOI: 10.1016/j.bcp.2015.04.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/20/2015] [Indexed: 01/10/2023]
Abstract
The aim of the present study was to determine the impact of α5 nicotinic acetylcholine receptor (nAChR) subunit deletion in the mouse on the development and intensity of nociceptive behavior in various chronic pain models. The role of α5-containing nAChRs was explored in mouse models of chronic pain, including peripheral neuropathy (chronic constriction nerve injury, CCI), tonic inflammatory pain (the formalin test) and short and long-term inflammatory pain (complete Freund's adjuvant, CFA and carrageenan tests) in α5 knock-out (KO) and wild-type (WT) mice. The results showed that paw-licking time was decreased in the formalin test, and the hyperalgesic and allodynic responses to carrageenan and CFA injections were also reduced. In addition, paw edema in formalin-, carrageenan- or CFA-treated mice were attenuated in α5-KO mice significantly. Furthermore, tumor necrosis factor-alpha (TNF-α) levels of carrageenan-treated paws were lower in α5-KO mice. The antinociceptive effects of nicotine and sazetidine-A but not varenicline were α5-dependent in the formalin test. Both hyperalgesia and allodynia observed in the CCI test were reduced in α5-KO mice. Nicotine reversal of mechanical allodynia in the CCI test was mediated through α5-nAChRs at spinal and peripheral sites. In summary, our results highlight the involvement of the α5 nAChR subunit in the development of hyperalgesia, allodynia and inflammation associated with chronic neuropathic and inflammatory pain models. They also suggest the importance of α5-nAChRs as a target for the treatment of chronic pain.
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Affiliation(s)
- Deniz Bagdas
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298-0613, United States; Experimental Animals Breeding and Research Center, Faculty of Medicine, Uludag University, Bursa 16059, Turkey
| | - Shakir D AlSharari
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298-0613, United States; Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Saudi Arabia
| | - Kelen Freitas
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298-0613, United States
| | - Matthew Tracy
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298-0613, United States
| | - M Imad Damaj
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298-0613, United States.
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The inimitable kynurenic acid: The roles of different ionotropic receptors in the action of kynurenic acid at a spinal level. Brain Res Bull 2015; 112:52-60. [DOI: 10.1016/j.brainresbull.2015.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/08/2015] [Accepted: 02/02/2015] [Indexed: 10/24/2022]
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7
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Xanthos DN, Beiersdorf JW, Thrun A, Ianosi B, Orr-Urtreger A, Huck S, Scholze P. Role of α5-containing nicotinic receptors in neuropathic pain and response to nicotine. Neuropharmacology 2015; 95:37-49. [PMID: 25725336 DOI: 10.1016/j.neuropharm.2015.02.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 02/03/2015] [Accepted: 02/10/2015] [Indexed: 11/26/2022]
Abstract
Nicotinic receptors in the central nervous system (nAChRs) are known to play important roles in pain processing and modulate behavioral responses to analgesic drugs, including nicotine. The presence of the α5-neuronal nicotinic accessory subunit in the nicotinic receptor complex is increasingly understood to modulate reward and aversive states, addiction, and possibly pathological pain. In the current study, using α5-knockout (KO) mice and subunit-specific antibodies, we assess the role of α5-containing neuronal nicotinic receptors in neuropathic pain and in the analgesic response to nicotine. After chronic constriction injury (CCI) or partial sciatic nerve ligation (PSNL), no differences in mechanical, heat, or cold hyperalgesia were found in wild-type (WT) versus α5-KO littermate mice. The number of α5-containing nAChRs was decreased (rather than increased) after CCI in the spinal cord and in the thalamus. Nevertheless, thermal analgesic response to nicotine was marginally reduced in CCI α5-KO mice at 4 days after CCI, but not at later timepoints or after PSNL. Interestingly, upon daily intermittent nicotine injections in unoperated mice, WT animals developed tolerance to nicotine-induced analgesia to a larger extent than α5-KO mice. Our results suggest that α5-containing nAChRs mediate analgesic tolerance to nicotine but do not play a major role in neuropathic pain.
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Affiliation(s)
- Dimitris N Xanthos
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria.
| | - Johannes W Beiersdorf
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria
| | - Ariane Thrun
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria
| | - Bogdan Ianosi
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria
| | - Avi Orr-Urtreger
- The Genetic Institute, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel; The Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Sigismund Huck
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria.
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Loram LC, Taylor FR, Strand KA, Maier SF, Speake JD, Jordan KG, James JW, Wene SP, Pritchard RC, Green H, Van Dyke K, Mazarov A, Letchworth SR, Watkins LR. Systemic administration of an alpha-7 nicotinic acetylcholine agonist reverses neuropathic pain in male Sprague Dawley rats. THE JOURNAL OF PAIN 2013. [PMID: 23182225 DOI: 10.1016/j.jpain.2012.08.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
UNLABELLED Alpha-7 nicotinic acetylcholine receptor (α7 nAChR) agonists attenuate pain and inflammation in preclinical models. This study tested whether systemic delivery of an α7 nAChR agonist attenuates neuropathic pain and associated immune-mediated pro-inflammation. Hind paw response thresholds to mechanical stimuli in male Sprague Dawley rats were assessed before and after sciatic chronic constriction injury (CCI) or sham surgery. Osmotic mini-pumps containing TC-7020, an α7 nAChR selective agonist, were implanted 10 to 14 days after surgery. TC-7020 (1, 3, and 10 mg/kg/d; s.c.) significantly attenuated CCI-induced allodynia, which lasted through 2 weeks of test compound administration. Spinal cords were collected after 2 weeks and processed for microglial and astrocyte activation markers within the ipsilateral L4-L6 dorsal horn. In addition, ipsilateral L4-5 dorsal root ganglia (DRGs) were processed for neuronal injury and satellite cell activation markers. CCI-induced central glial cell activation markers were not suppressed by TC-7020, even though TC-7020 is mildly blood-brain barrier permeable. However, TC-7020 downregulated the integrated density of activation transcription factor 3 (ATF3) but not the number of ATF positive cells. TC-7020 also downregulated phosphorylated extracellular signal kinase (p-ERK) and satellite cell activation in the CCI-affected DRGs. Therefore, systemic α7 nAChR agonist may be effective in treating neuropathic pain via reducing neuronal injury and immune cells activation occurring in the periphery. PERSPECTIVE These studies demonstrated that TC-7020, an alpha7 nicotinic acetylcholine receptor agonist with partial blood-brain barrier permeability, reversed neuropathic pain in rats, likely via attenuation of inflammation in the DRG and/or the site of sciatic injury.
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Affiliation(s)
- Lisa C Loram
- Department of Psychology & Neuroscience, and Center for Neuroscience, University of Colorado at Boulder, Boulder, CO, USA.
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Fowler CD, Tuesta L, Kenny PJ. Role of α5* nicotinic acetylcholine receptors in the effects of acute and chronic nicotine treatment on brain reward function in mice. Psychopharmacology (Berl) 2013; 229:10.1007/s00213-013-3235-1. [PMID: 23958943 PMCID: PMC3930613 DOI: 10.1007/s00213-013-3235-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/30/2013] [Indexed: 01/06/2023]
Abstract
OBJECTIVE Allelic variation in the α5 nicotinic acetylcholine receptor (nAChR) subunit gene, CHRNA5, increases vulnerability to tobacco addiction. Here, we investigated the role of α5* nAChRs in the effects of nicotine on brain reward systems. MATERIALS AND METHODS Effects of acute (0.03125-0.5 mg/kg SC) or chronic (24 mg/kg per day; osmotic minipump) nicotine and mecamylamine-precipitated withdrawal on intracranial self-stimulation (ICSS) thresholds were assessed in wild-type and α5 nAChR subunit knockout mice. Noxious effects of nicotine were further investigated using a conditioned taste aversion procedure. RESULTS Lower nicotine doses (0.03125-0.125 mg/kg) decreased ICSS thresholds in wild-type and α5 knockout mice. At higher doses (0.25-0.5 mg/kg), threshold-lowering effects of nicotine were diminished in wild-type mice, whereas nicotine lowered thresholds across all doses tested in α5 knockout mice. Nicotine (1.5 mg/kg) conditioned a taste aversion to saccharine equally in both genotypes. Mecamylamine (5 mg/kg) elevated ICSS thresholds by a similar magnitude in wild-type and α5 knockout mice prepared with minipumps delivering nicotine. Unexpectedly, mecamylamine also elevated thresholds in saline-treated α5 knockout mice. CONCLUSION α5* nAChRs are not involved in reward-enhancing effects of lower nicotine doses, the reward-inhibiting effects of nicotine withdrawal, or the general noxious effects of higher nicotine doses. Instead, α5* nAChRs regulate the reward-inhibiting effects nicotine doses that oppose the reward-facilitating effects of the drug. These data suggest that disruption of α5* nAChR signaling greatly expands the range of nicotine doses that facilitate brain reward activity, which may help explain the increased tobacco addiction vulnerability associated with CHRNA5 risk alleles.
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Affiliation(s)
- Christie D Fowler
- Laboratory of Behavioral and Molecular Neuroscience, Department of Molecular Therapeutics, The Scripps Research Institute-Florida, 130 Scripps Way, Jupiter, FL, 33458, USA
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Ondansetron reverses antihypersensitivity from clonidine in rats after peripheral nerve injury: role of γ-aminobutyric acid in α2-adrenoceptor and 5-HT3 serotonin receptor analgesia. Anesthesiology 2012; 117:389-98. [PMID: 22722575 DOI: 10.1097/aln.0b013e318260d381] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Monoaminergic pathways, impinging an α2-adrenoceptors and 5-HT3 serotonin receptors, modulate nociceptive transmission, but their mechanisms and interactions after neuropathic injury are unknown. Here we examine these interactions in rodents after nerve injury. METHODS Male Sprague-Dawley rats following L5-L6 spinal nerve ligation (SNL) were used for either behavioral testing, in vivo microdialysis for γ-aminobutyric acid (GABA) and acetylcholine release, or synaptosome preparation for GABA release. RESULTS Intrathecal administration of the α2-adrenoceptor agonist (clonidine) and 5-HT3 receptor agonist (chlorophenylbiguanide) reduced hypersensitivity in SNL rats via GABA receptor-mediated mechanisms. Clonidine increased GABA and acetylcholine release in vivo in the spinal cord of SNL rats but not in normal rats. Clonidine-induced spinal GABA release in SNL rats was blocked by α2-adrenergic and nicotinic cholinergic antagonists. The 5-HT3 receptor antagonist ondansetron decreased and chlorophenylbiguanide increased spinal GABA release in both normal and SNL rats. In synaptosomes from the spinal dorsal horn of SNL rats, presynaptic GABA release was increased by nicotinic agonists and decreased by muscarinic and α2-adrenergic agonists. Spinally administered ondansetron significantly reduced clonidine-induced antihypersensitivity and spinal GABA release in SNL rats. CONCLUSION These results suggest that spinal GABA contributes to antihypersensitivity from intrathecal α2-adrenergic and 5-HT3 receptor agonists in the neuropathic pain state, that cholinergic neuroplasticity after nerve injury is critical for α2-adrenoceptor-mediated GABA release, and that blockade of spinal 5-HT3 receptors reduces α2-adrenoceptor-mediated antihypersensitivity via reducing total GABA release.
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Munro G, Dyhr H, Grunnet M. Selective potentiation of gabapentin-mediated antinociception in the rat formalin test by the nicotinic acetylcholine receptor agonist ABT-594. Neuropharmacology 2010; 59:208-17. [DOI: 10.1016/j.neuropharm.2010.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 05/24/2010] [Accepted: 05/24/2010] [Indexed: 10/19/2022]
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12
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Loram LC, Harrison JA, Chao L, Taylor FR, Reddy A, Travis CL, Giffard R, Al-Abed Y, Tracey K, Maier SF, Watkins LR. Intrathecal injection of an alpha seven nicotinic acetylcholine receptor agonist attenuates gp120-induced mechanical allodynia and spinal pro-inflammatory cytokine profiles in rats. Brain Behav Immun 2010; 24:959-67. [PMID: 20353818 PMCID: PMC2902784 DOI: 10.1016/j.bbi.2010.03.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 03/23/2010] [Accepted: 03/24/2010] [Indexed: 12/29/2022] Open
Abstract
Nicotinic acetylcholine receptors (nAchRs) are not only key receptors in the autonomic nervous system, but also are present on immune cells. The alpha seven subunit of nAchR (alpha7nAchR) suppresses pro-inflammation in peripheral monocytes by decreasing pro-inflammatory cytokine production. In spinal cord, alpha7nAchRs are found on microglia, which are known to induce and maintain pain. We predicted that alpha7nAchR agonists might attenuate intrathecal HIV-1 gp120-induced, pro-inflammatory cytokine- and microglia-dependent mechanical allodynia. Choline, a precursor for acetylcholine and selective agonist for alpha7nAchR, was administered intrathecally either with, or 30 min after, intrathecal gp120. Choline significantly blocked and reversed gp120-induced mechanical allodynia for at least 4 h after drug administration. In addition, intrathecal choline, delivered either with or 30 min after gp120, reduced gp120-induced IL-1beta protein and pro-inflammatory cytokine mRNAs within the lumbar spinal cord. A second alpha7nAchR agonist, GTS-21, also significantly reversed gp120-induced mechanical allodynia and lumbar spinal cord levels of pro-inflammatory cytokine mRNAs and IL-1beta protein. A role of microglia is suggested by the observation that intrathecal choline suppressed the gp120-induced expression of, cd11b, a macrophage/microglial activation marker. Taken together, the data support that alpha7nAchR may be a novel target for treating pain where microglia maintain the pro-inflammatory state within the spinal cord.
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Affiliation(s)
- Lisa C Loram
- Department of Psychology & Neuroscience, University of Colorado, Boulder, CO 80309, USA.
| | - Jacqueline A Harrison
- Department of Psychology & Neuroscience, and Center for Neuroscience, University of Colorado at Boulder, Colorado, USA
| | - Lindsey Chao
- Department of Psychology & Neuroscience, and Center for Neuroscience, University of Colorado at Boulder, Colorado, USA
| | - Frederick R Taylor
- Department of Psychology & Neuroscience, and Center for Neuroscience, University of Colorado at Boulder, Colorado, USA
| | - Anireddy Reddy
- Department of Psychology & Neuroscience, and Center for Neuroscience, University of Colorado at Boulder, Colorado, USA
| | - Carissa L Travis
- Department of Psychology & Neuroscience, and Center for Neuroscience, University of Colorado at Boulder, Colorado, USA
| | - Rona Giffard
- Department of Anesthesia, Stanford University School of Medicine, Stanford, California, USA
| | - Yousef Al-Abed
- Laboratory of Medicinal Chemistry and Center for Immunology and Inflammation, The Feinstein Institute for Medical Research, North Shore-LIJ Health System, New York, USA
| | - Kevin Tracey
- Laboratory of Medicinal Chemistry and Center for Immunology and Inflammation, The Feinstein Institute for Medical Research, North Shore-LIJ Health System, New York, USA
| | - Steven F Maier
- Department of Psychology & Neuroscience, and Center for Neuroscience, University of Colorado at Boulder, Colorado, USA
| | - Linda R Watkins
- Department of Psychology & Neuroscience, and Center for Neuroscience, University of Colorado at Boulder, Colorado, USA
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Ueda M, Iida Y, Yoneyama T, Kawai T, Ogawa M, Magata Y, Saji H. In vivo relationship between thalamic nicotinic acetylcholine receptor occupancy rates and antiallodynic effects in a rat model of neuropathic pain: Persistent agonist binding inhibits the expression of antiallodynic effects. Synapse 2010; 65:77-83. [DOI: 10.1002/syn.20819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Waldinger MD, De Lint GJ, Venema PL, Van Gils AP, Schweitzer DH. ORIGINAL RESEARCH—WOMEN'S SEXUAL HEALTH: Successful Transcutaneous Electrical Nerve Stimulation in Two Women with Restless Genital Syndrome: The Role of Aδ- and C-Nerve Fibers. J Sex Med 2010; 7:1190-9. [DOI: 10.1111/j.1743-6109.2009.01578.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Moriwaki Y, Watanabe Y, Shinagawa T, Kai M, Miyazawa M, Okuda T, Kawashima K, Yabashi A, Waguri S, Misawa H. Primary sensory neuronal expression of SLURP-1, an endogenous nicotinic acetylcholine receptor ligand. Neurosci Res 2009; 64:403-12. [DOI: 10.1016/j.neures.2009.04.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 04/20/2009] [Accepted: 04/21/2009] [Indexed: 10/20/2022]
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