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Ramawad HA, Paridari P, Jabermoradi S, Gharin P, Toloui A, Safari S, Yousefifard M. Muscimol as a treatment for nerve injury-related neuropathic pain: a systematic review and meta-analysis of preclinical studies. Korean J Pain 2023; 36:425-440. [PMID: 37732408 PMCID: PMC10551397 DOI: 10.3344/kjp.23161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 09/22/2023] Open
Abstract
Background : Muscimol's quick onset and GABAergic properties make it a promising candidate for the treatment of pain. This systematic review and meta-analysis of preclinical studies aimed at summarizing the evidence regarding the efficacy of muscimol administration in the amelioration of nerve injury-related neuropathic pain. Methods : Two independent researchers performed the screening process in Medline, Embase, Scopus and Web of Science extracting data were extracted into a checklist designed according to the PRISMA guideline. A standardized mean difference (SMD [95% confidence interval]) was calculated for each. To assess the heterogeneity between studies, I2 and chi-square tests were utilized. In the case of heterogeneity, meta-regression and subgroup analyses were performed to identify the potential source. Results : Twenty-two articles met the inclusion criteria. Pooled data analysis showed that the administration of muscimol during the peak effect causes a significant reduction in mechanical allodynia (SMD = 1.78 [1.45-2.11]; P < 0.0001; I2 = 72.70%), mechanical hyperalgesia (SMD = 1.62 [1.28-1.96]; P < 0.0001; I2 = 40.66%), and thermal hyperalgesia (SMD = 2.59 [1.79-3.39]; P < 0.0001; I2 = 80.33%). This significant amendment of pain was observed at a declining rate from 15 minutes to at least 180 minutes post-treatment in mechanical allodynia and mechanical hyperalgesia, and up to 30 minutes in thermal hyperalgesia (P < 0 .0001). Conclusions : Muscimol is effective in the amelioration of mechanical allodynia, mechanical hyperalgesia, and thermal hyperalgesia, exerting its analgesic effects 15 minutes after administration for up to at least 3 hours.
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Affiliation(s)
- Hamzah Adel Ramawad
- Department of Emergency Medicine, NYC Health + Hospitals, Coney Island, NY, USA
| | - Parsa Paridari
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sajjad Jabermoradi
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Pantea Gharin
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Amirmohammad Toloui
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Saeed Safari
- Men's Health and Reproductive Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahmoud Yousefifard
- Physiology Research Center, Iran University of Medical Sciences, Tehran, Iran
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2
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Abstract
A substantial fraction of the human population suffers from chronic pain states, which often cannot be sufficiently treated with existing drugs. This calls for alternative targets and strategies for the development of novel analgesics. There is substantial evidence that the G protein-coupled GABAB receptor is involved in the processing of pain signals and thus has long been considered a valuable target for the generation of analgesics to treat chronic pain. In this review, the contribution of GABAB receptors to the generation and modulation of pain signals, their involvement in chronic pain states as well as their target suitability for the development of novel analgesics is discussed.
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Affiliation(s)
- Dietmar Benke
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
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3
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Sadeghi M, Manaheji H, Zaringhalam J, Haghparast A, Nazemi S, Bahari Z, Noorbakhsh SM. Evaluation of the GABAA Receptor Expression and the Effects of Muscimol on the Activity of Wide Dynamic Range Neurons Following Chronic Constriction Injury of Sciatic Nerve in Rats. Basic Clin Neurosci 2021; 12:651-666. [PMID: 35173919 PMCID: PMC8818116 DOI: 10.32598/bcn.2021.1726.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/05/2020] [Accepted: 08/02/2021] [Indexed: 11/20/2022] Open
Abstract
Introduction The modality of γ-aminobutyric acid type a receptors (GABAA) controls dorsal horn neuronal excitability and inhibits sensory information. This study aimed to investigate the expression of the GABAA receptor and the effects of its agonist muscimol on Wide Dynamic Range (WDR) neuronal activity in the Chronic Constriction Injury (CCI) model of neuropathic pain. Methods Adult male Wistar rats weighing 200 to 250 g were used to induce CCI neuropathy. Fourteen days after surgery, muscimol (0.5, 1, and 2 mg/kg IP) was injected. Then, the behavioral tests were performed. After that, the animals were killed, and the lumbar segments of the spinal cords were collected for Western blot analysis of the GABAA receptor α1 subunit expression. The electrophysiological properties of WDR neurons were studied by single-unit recordings in separate groups 14 days after CCI. Results The outcomes indicated the development of thermal hyperalgesia and mechanical allodynia after neuropathy; nonetheless, the expression of the GABAA receptor α1 subunit did not change significantly. Moreover, the evoked responses of the WDR neurons to electrical, mechanical, and thermal stimuli increased considerably. Fourteen days after CCI, muscimol administration decreased thermal hyperalgesia, mechanical allodynia, and hyper-responsiveness of the WDR neurons in CCI rats. Conclusion The modulation of the spinal GABAA receptors after nerve injury can offer further insights to design new therapeutic agents to reduce neuropathic pain symptoms.
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Affiliation(s)
- Mehdi Sadeghi
- Department of Physiology, Faculty of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Homa Manaheji
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Jalal Zaringhalam
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Haghparast
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Samad Nazemi
- Department of Physiology, Faculty of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Zahra Bahari
- Department of Physiology and Medical Physics, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Seyed Mohammad Noorbakhsh
- Department of Physiology, Faculty of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
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Jain V, Pareek A, Bhardwaj YR, Sinha SK, Gupta MM, Singh N. Punicalagin and ellagic acid containing Punica granatum L. fruit rind extract prevents vincristine-induced neuropathic pain in rats: an in silico and in vivo evidence of GABAergic action and cytokine inhibition. Nutr Neurosci 2021; 25:2149-2166. [PMID: 34369317 DOI: 10.1080/1028415x.2021.1954293] [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] [Indexed: 12/18/2022]
Abstract
Objectives: We aimed to investigate the protective potential of Punica granatum L. fruit rind extract (PFE) containing punicalagin (10.3% W/W), ellagic acid (EA) (2.7%W/W) in vincristine (75 µg/kg i.p.)- induced neuropathic pain in Wistar rats.Methods: Docking simulation studies were done on the three-dimensional (3D) structure of the GABAA and PPAR γ receptor for the binding of EA as well as punicalagin docking studies on TNF-α, and IL-6. The Present Study conceptualized a test battery to evaluate the behavioral, biochemical and histological changes.Results: Vincristine -induced significant cold allodynia, mechanical hyperalgesia, and functional deficit on 12th and 21st days. It also increased in the levels of TNF-α (Tumor necrosis factor-α), IL-6 (Interleukin-6), and MPO (Myeloperoxidase). Administration of PFE (100 and 300 mg/kg, p.o.), EA (50 mg/kg), and gabapentin (100 mg/kg) attenuated Vincristine-induced behavioral and biochemical changes significantly (P < .05). PFE showed better antinociceptive activity to EA. The histopathological evaluation also revealed the protective effects of PFE. Pretreatment of bicuculline (selective antagonist of GABAA receptors) reversed antinociceptive action of PFE, but administration of γ aminobutyric acid potentiated the action of PFE. PPAR-γ antagonist BADGE did not modify the effect of PFE. Docking results revealed that EA properly positioned into GABA and PPARγ binding site and acts as a partial agonist. Docking score of Punicalagin found to be - 9.02 kcal/mol and - 8.32 kcal/mol on IL-6 and TNFα respectively.Discussion: Conclusively, the attenuating effect of PFE may be attributed to the GABAergic system, cytokine inhibition, and anti-inflammatory activities.
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Affiliation(s)
- Vivek Jain
- Department of Pharmaceutical Sciences, Mohanlal Sukhadia University, Udaipur, Rajasthan, India.,Department of Pharmacy, Banasthali University, Banasthali, India
| | - Ashutosh Pareek
- Department of Pharmacy, Banasthali University, Banasthali, India
| | | | - Saurabh Kumar Sinha
- Department of Pharmaceutical Sciences, Mohanlal Sukhadia University, Udaipur, Rajasthan, India
| | - Madan Mohan Gupta
- School of Pharmacy, Faculty of Medical Sciences, The University of the West Indies, St Augustine, Trinidad & Tobago, West Indies
| | - Nirmal Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
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5
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Ge MM, Chen SP, Zhou YQ, Li Z, Tian XB, Gao F, Manyande A, Tian YK, Yang H. The therapeutic potential of GABA in neuron-glia interactions of cancer-induced bone pain. Eur J Pharmacol 2019; 858:172475. [DOI: 10.1016/j.ejphar.2019.172475] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 01/06/2023]
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6
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Yi MH, Shin J, Shin N, Yin Y, Lee SY, Kim CS, Kim SR, Zhang E, Kim DW. PINK1 mediates spinal cord mitophagy in neuropathic pain. J Pain Res 2019; 12:1685-1699. [PMID: 31239755 PMCID: PMC6554001 DOI: 10.2147/jpr.s198730] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/24/2019] [Indexed: 01/13/2023] Open
Abstract
Background: Mitophagy is the selective engulfment of mitochondria by autophagosomes and the subsequent mitochondrial catabolism by lysosomes. Evidence has suggested an important role for mitochondrial dynamics and mitophagic flux in the development of many different neurodegenerative diseases. Objectives: The potential role of the mechanism underlying mitochondrial dynamics and mitophagic flux as it may relate to neuropathic pain is not well understood. This is a disease that largely remains an area of mechanistic uncertainty. PINK1 is a PTEN-induced mitochondrial kinase that can be selectively activated under mitochondrial stress conditions and lead to the induction of mitophagy. Materials and methods: A neuropathic pain rat model was established via spinal nerve ligation (SNL) and nociception was assayed via the von Frey filament method. Increased expression of PINK1 and the mechanism of mitophagy was detected in GABAergic interneurons of dorsal horn neurons of mice that underwent L5 SNL in comparison to control mice counterparts (n=8, P<0.001) by Western blotting, immunohistochemistry and double immunofluorescence staining. Results: Elevated expression of PINK1 appeared to localize selectively to GABAergic interneurons, particularly within autophagic mitochondria as evidenced by co-localization studies of PINK1 with BECN1, LC3II and COX IV on immunofluorescent microscopy. Furthermore, we also detected a significant increase in autophagosomes in dorsal horn neurons of SNL mice and this was consistent with increased autophagic activity as measured by the p62 autophagic substrate. Conclusion: These results demonstrate that neuropathic pain causes aberrant mitophagic flux selectively in GABAergic interneurons and provide evidence implicating mitophagy as an important area of future molecular studies to enhance our understanding of neuropathic pain.
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Affiliation(s)
- Min-Hee Yi
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Juhee Shin
- Department of Anatomy, Brain Research Institute, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea.,Department of Medical Science, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea
| | - Nara Shin
- Department of Anatomy, Brain Research Institute, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea.,Department of Medical Science, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea
| | - Yuhua Yin
- Department of Anatomy, Brain Research Institute, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea.,Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon 301-747, South Korea
| | - Sun Yeul Lee
- Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon 301-747, South Korea
| | - Cuk-Seong Kim
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea.,Department of Physiology, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea
| | - Sang Ryong Kim
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Institute of Life Science & Biotechnology, Brain Science and Engineering Institute, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Enji Zhang
- Department of Anesthesia Medicine, Yanbian University Hospital, Yanbian 133000, People's Republic of China
| | - Dong Woon Kim
- Department of Anatomy, Brain Research Institute, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea.,Department of Medical Science, Chungnam National University School of Medicine, Daejeon 301-747, Republic of Korea
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7
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Khangura RK, Sharma J, Bali A, Singh N, Jaggi AS. An integrated review on new targets in the treatment of neuropathic pain. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2019; 23:1-20. [PMID: 30627005 PMCID: PMC6315088 DOI: 10.4196/kjpp.2019.23.1.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/12/2018] [Accepted: 09/17/2018] [Indexed: 01/01/2023]
Abstract
Neuropathic pain is a complex chronic pain state caused by the dysfunction of somatosensory nervous system, and it affects the millions of people worldwide. At present, there are very few medical treatments available for neuropathic pain management and the intolerable side effects of medications may further worsen the symptoms. Despite the presence of profound knowledge that delineates the pathophysiology and mechanisms leading to neuropathic pain, the unmet clinical needs demand more research in this field that would ultimately assist to ameliorate the pain conditions. Efforts are being made globally to explore and understand the basic molecular mechanisms responsible for somatosensory dysfunction in preclinical pain models. The present review highlights some of the novel molecular targets like D-amino acid oxidase, endoplasmic reticulum stress receptors, sigma receptors, hyperpolarization-activated cyclic nucleotide-gated cation channels, histone deacetylase, Wnt/β-catenin and Wnt/Ryk, ephrins and Eph receptor tyrosine kinase, Cdh-1 and mitochondrial ATPase that are implicated in the induction of neuropathic pain. Studies conducted on the different animal models and observed results have been summarized with an aim to facilitate the efforts made in the drug discovery. The diligent analysis and exploitation of these targets may help in the identification of some promising therapies that can better manage neuropathic pain and improve the health of patients.
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Affiliation(s)
- Ravneet Kaur Khangura
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India
| | - Jasmine Sharma
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India
| | - Anjana Bali
- Akal College of Pharmacy and Technical Education, Mastuana Sahib 148002, Sangrur, India
| | - Nirmal Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India
| | - Amteshwar Singh Jaggi
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala 147002, India
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8
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Impaired Autophagy of GABAergic Interneurons in Neuropathic Pain. Pain Res Manag 2018; 2018:9185368. [PMID: 30356379 PMCID: PMC6176324 DOI: 10.1155/2018/9185368] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/12/2018] [Indexed: 12/30/2022]
Abstract
Neuropathic pain (NP) is caused by lesions of the peripheral fibers and central neurons in the somatosensory nervous system and affects 7-10% of the general population. Although the distinct cause of neuropathic pain has been investigated in primary afferent neurons over the years, pain modulation by central sensitization remains controversial. NP is believed to be driven by cell type-specific spinal synaptic plasticity in the dorsal horn. Upon intense afferent stimulation, spinothalamic tract neurons are potentiated, whereas GABAergic interneurons are inhibited leading to long-term depression. Growing evidences suggest that the inhibition of GABAergic neurons plays pivotal roles in the manifestation of neuropathic and inflammatory pain states. Downregulation of GABA transmission and impairment of GABAergic interneurons in the dorsal horn are critical consequences after spinal cord and peripheral nerve injuries. These impairments in GABAergic interneurons may be associated with dysfunctional autophagy, resulting in neuropathic pain. Here, we review an emerging number of investigations that suggest a pivotal role of impaired autophagy of GABAergic interneurons in NP. We discuss relevant research spurring the development of new targets and therapeutic agents of NP and emphasize the need for a multidisciplinary approach to manage NP in the future.
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9
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Ovalle-Magallanes B, Déciga-Campos M, Mata R. Antihyperalgesic activity of a mexicanolide isolated from Swietenia humilis extract in nicotinamide-streptozotocin hyperglycemic mice. Biomed Pharmacother 2017; 92:324-330. [DOI: 10.1016/j.biopha.2017.05.073] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/02/2017] [Accepted: 05/15/2017] [Indexed: 10/19/2022] Open
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10
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Yin H, Bhattarai JP, Oh SM, Park SJ, Ahn DK, Han SK. Baicalin Activates Glycine and γ-Aminobutyric Acid Receptors on Substantia Gelatinosa Neurons of the Trigeminal Subsnucleus Caudalis in Juvenile Mice. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2016; 44:389-400. [PMID: 27080947 DOI: 10.1142/s0192415x16500221] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) receives nociceptive afferent inputs from thin-myelinated A[Formula: see text] fibers and unmyelinated C fibers and has been shown to be involved in the processing of orofacial nociceptive information. Scutellaria baicalensis Georgi (Huang-Qin, SbG), one of the 50 fundamental herbs of Chinese herbology, has been used historically as anti-inflammatory and antineoplastic medicine. Baicalin, one of the major compounds of SbG, has been reported to have neuroprotective, anti-inflammatory and analgesic effects. However, the receptor type activated by baicalin and its precise action mechanism on the SG neurons of Vc have not yet been studied. The whole-cell patch clamp technique was performed to examine the ion channels activated by baicalin on the SG neurons of Vc. In high Cl[Formula: see text] pipette solution, the baicalin (300[Formula: see text][Formula: see text]M) induced repeatable inward currents ([Formula: see text][Formula: see text]pA, [Formula: see text]) without desensitization on all the SG neurons tested. Further, the inward currents showed a concentration (0.1-3[Formula: see text]mM) dependent pattern. The inward current was sustained in the presence of tetrodotoxin (0.5[Formula: see text][Formula: see text]M), a voltage sensitive Na[Formula: see text] channel blocker. In addition, baicalin-induced inward currents were reduced in the presence of picrotoxin (50[Formula: see text][Formula: see text]M), a GABAA receptor antagonist, flumazenil (100[Formula: see text][Formula: see text]M), a benzodiazepine-sensitive GABAA receptor antagonist, and strychnine (2[Formula: see text][Formula: see text]M), a glycine receptor antagonist, respectively. These results indicate that baicalin has inhibitory effects on the SG neurons of the Vc, which are due to the activation of GABAA and/or the glycine receptor. Our results suggest that baicalin may be a potential target for orofacial pain modulation.
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Affiliation(s)
- Hua Yin
- * Department of Oral Physiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju 561-756, Republic of Korea
| | - Janardhan Prasad Bhattarai
- * Department of Oral Physiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju 561-756, Republic of Korea
| | - Sun Mi Oh
- * Department of Oral Physiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju 561-756, Republic of Korea
| | - Soo Joung Park
- * Department of Oral Physiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju 561-756, Republic of Korea
| | - Dong Kuk Ahn
- † Department of Oral Physiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Seong Kyu Han
- * Department of Oral Physiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju 561-756, Republic of Korea
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Akbar S, Subhan F, Karim N, Shahid M, Ahmad N, Ali G, Mahmood W, Fawad K. 6-Methoxyflavanone attenuates mechanical allodynia and vulvodynia in the streptozotocin-induced diabetic neuropathic pain. Biomed Pharmacother 2016; 84:962-971. [PMID: 27764759 DOI: 10.1016/j.biopha.2016.10.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 10/03/2016] [Accepted: 10/06/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Diabetic neuropathy is the most prevalent, persistent and debilitating complication of diabetes mellitus often coupled with vulvodynia that may present as an isolated symptom or as a part of constellation of other neuropathic abnormalities. OBJECTIVE Flavonoids have selective affinity for GABA receptors and 6-methoxyflavanone (6-MeOF) is a positive allosteric modulator of GABA responses at human recombinant GABAA receptors. GABAergic and opioidergic system inhibition have been shown to facilitate neuropathic pain. METHODS 6-MeOF was evaluated for analgesic effect in the hot plate test and streptozotocin-induced diabetic neuropathic pain in female rats using von Frey hairs. The possible involvement of opioidergic and GABAergic mechanisms was investigated using naloxone and pentylenetetrazole (PTZ) antagonists, respectively. The biodistribution of 6-MeOF in plasma and CNS was examined using a validated HPLC/UV analytical method. The binding affinity of 6-MeOF with opioid and GABA receptors was studied using molecular docking simulation approach. RESULTS 6-MeOF (10 and 30mg/kg) attenuated the acute phasic thermal nociception in the hot plate test while in the case of streptozotocin-induced diabetic neuropathy model, 6-MeOF (10 and 30mg/kg) produced static/dynamic anti-allodynic (increased paw withdrawal threshold and latency) as well as static/dynamic anti-vulvodynic effects (increased flinching response threshold and latency), when compared to the vehicle and standard gabapentin (75mg/kg). In silico studies depicted the preference of 6-MeOF for the delta- and kappa-opioid and GABAA receptors. Moreover, the pharmacokinetic profile revealed a quick appearance of 6-MeOF in the systemic circulation and brain areas with maximum concentration observed after 30min in the amygdala, brain stem and cerebral cortex. CONCLUSION 6-MeOF readily crosses the blood brain barrier and may be effective in attenuating the diabetes-induced allodynia as well as vulvodynia, probably through interactions with the GABAergic and opioidergic systems.
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Affiliation(s)
- Shehla Akbar
- Department of Pharmacy, University of Peshawar, Peshawar, Pakistan.
| | - Fazal Subhan
- Department of Pharmacy, University of Peshawar, Peshawar, Pakistan.
| | - Nasiara Karim
- Department of Pharmacy, University of Malakand, Chakdara, Pakistan.
| | - Muhammad Shahid
- Department of Pharmacy, University of Peshawar, Peshawar, Pakistan.
| | - Nisar Ahmad
- Department of Pharmacy, University of Peshawar, Peshawar, Pakistan.
| | - Gowhar Ali
- Department of Pharmacy, University of Peshawar, Peshawar, Pakistan.
| | - Wajahat Mahmood
- Department of Pharmacy, COMSATS Institute of Information Technology, Abbottabad, Pakistan.
| | - Khwaja Fawad
- Department of Pharmacy, University of Peshawar, Peshawar, Pakistan.
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12
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Masocha W. Comprehensive analysis of the GABAergic system gene expression profile in the anterior cingulate cortex of mice with Paclitaxel-induced neuropathic pain. Gene Expr 2015; 16:145-53. [PMID: 25700370 PMCID: PMC8750099 DOI: 10.3727/105221615x14181438356337] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The supraspinal pathophysiology of the painful neuropathy induced by paclitaxel, a chemotherapeutic agent, is not well understood. The γ-aminobutyric acid (GABA) neurotransmitter system has been implicated in the pathogenesis of neuropathic pain. Gene expression of GABAergic system molecules was examined in the anterior cingulate cortex (ACC) of mice brains, by real-time PCR, during paclitaxel-induced neuropathic pain, because this area is involved in pain perception and modulation that might contribute to neuropathic pain. Paclitaxel treatment resulted in thermal hyperalgesia and in increased GABA transporter-1 (GAT-1) mRNA expression, but not that of other GABA transporters or GABA(A) ergic enzymes in the ACC compared to vehicle treatment. Among the 18 GABA(A) receptor subunits analyzed, only β2, β3, δ, and γ2 had increased mRNA levels, and for the receptor subunit, only GABA(B2) had increased mRNA levels in the ACC of paclitaxel-treated mice, whereas the rest of the GABA receptor subunits were not altered. The mRNA expression of GABAA receptor subunits α6, θ, π, ρ1, ρ2, and ρ3 were not detected in the ACC. In conclusion, these data show that during paclitaxel-induced neuropathic pain there is significant increase in GAT-1 expression in the ACC. GAT-1 is the main transporter of GABA from the synapse, and thus its increased expression possibly results in less GABA at the synapse and dysregulation of the GABAergic system. GAT-1 is a potential therapeutic target for managing paclitaxel-induced neuropathic pain.
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Affiliation(s)
- Willias Masocha
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Kuwait
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13
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Zhang E, Yi MH, Ko Y, Kim HW, Seo JH, Lee YH, Lee W, Kim DW. Expression of LC3 and Beclin 1 in the spinal dorsal horn following spinal nerve ligation-induced neuropathic pain. Brain Res 2013; 1519:31-9. [PMID: 23665054 DOI: 10.1016/j.brainres.2013.04.055] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/22/2013] [Accepted: 04/30/2013] [Indexed: 11/24/2022]
Abstract
Impaired spinal GABAergic inhibitory function is known to be pivotal in neuropathic pain (NPP). At present, data concerning time-dependent alterations in cell type and cell death in the spinal dorsal horn are highly controversial, likely related to the experimental NPP model used. In this study, we examined the expression of autophagy using a L5 spinal nerve ligation (SNL)-induced neuropathic pain rat model. Following ligation of the spinal nerve, neuropathic pain behavior, such as mechanical allodynia, was induced rapidly and maintained for 14 days. After testing for mechanical allodynia, we assessed the changes in expression of LC3 and Beclin 1 in the spinal cord following SNL. Immunohistochemical analysis showed that the levels of LC3 and Beclin 1 protein in the ipsilateral L5 spinal dorsal horn were significantly elevated on day 14 following SNL. Double immunohistochemical analysis further confirmed increases in LC3 and Beclin 1 in mostly neurons and a few astrocytes following SNL. LC3 and Beclin 1 expressions were upregulated in GABAergic interneurons of spinal dorsal horn after SNL, while the loss of GABAergic interneurons did not change significantly. Our results suggest that autophagic disruption in GABAergic interneurons and astrocytes following peripheral nerve injury might be involved in the induction and maintenance of neuropathic pain.
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Affiliation(s)
- Enji Zhang
- Department of Anesthesia and Pain Medicine, Chungnam National University Hospital, Daejeon, South Korea
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14
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Ultenius C, Song Z, Lin P, Meyerson BA, Linderoth B. Spinal GABAergic Mechanisms in the Effects of Spinal Cord Stimulation in a Rodent Model of Neuropathic Pain: Is GABA Synthesis Involved? Neuromodulation 2012; 16:114-20. [DOI: 10.1111/ner.12007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 10/09/2012] [Accepted: 10/25/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Camilla Ultenius
- Department of Clinical Neuroscience; Karolinska Institutet; Stockholm; Sweden
| | - Zhiyang Song
- Department of Clinical Neuroscience; Karolinska Institutet; Stockholm; Sweden
| | - Paoyan Lin
- Department of Clinical Neuroscience; Karolinska Institutet; Stockholm; Sweden
| | - Björn A. Meyerson
- Department of Clinical Neuroscience; Karolinska Institutet; Stockholm; Sweden
| | - Bengt Linderoth
- Department of Clinical Neuroscience; Karolinska Institutet; Stockholm; Sweden
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15
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Viguier F, Michot B, Kayser V, Bernard JF, Vela JM, Hamon M, Bourgoin S. GABA, but not opioids, mediates the anti-hyperalgesic effects of 5-HT7 receptor activation in rats suffering from neuropathic pain. Neuropharmacology 2012; 63:1093-106. [DOI: 10.1016/j.neuropharm.2012.07.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 07/03/2012] [Accepted: 07/10/2012] [Indexed: 12/12/2022]
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16
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Barr MS, Farzan F, Davis KD, Fitzgerald PB, Daskalakis ZJ. Measuring GABAergic inhibitory activity with TMS-EEG and its potential clinical application for chronic pain. J Neuroimmune Pharmacol 2012; 8:535-46. [PMID: 22744222 DOI: 10.1007/s11481-012-9383-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 06/14/2012] [Indexed: 12/13/2022]
Abstract
Chronic pain is debilitating disorder in which the underlying pathophysiology is still unknown. Impaired cortical inhibition is one mechanism that is associated with chronic pain. Cortical inhibition refers to a neurophysiological process in which gamma-aminobutyric acid (GABA) inhibitory interneurons selectively attenuate the activity of pyramidal neurons in the cortex. Previous studies have capitalized on the ability of transcranial magnetic stimulation (TMS) to index cortical inhibition by stimulating the motor cortex and measuring the resulting peripheral motor evoked potentials with electromyography. Chronic pain has been shown to induce changes in cortical inhibition within the motor cortex using TMS. Electroencephalography (EEG) studies also demonstrate that gamma (30-50 Hz) oscillations in the prefrontal and somatosensory cortex are associated with the experience of pain. As gamma oscillations are mediated by GABA, the combination of TMS with EEG allows for the examination of the relationship between cortical inhibition, gamma and chronic pain. In this paper, we summarize the evidence of impaired GABAergic and gamma oscillations in chronic pain patients. We then demonstrate TMS-EEG as a reliable method in which to record cortical inhibition directly from the prefrontal cortex to examine the modulatory effect of GABAB receptor inhibition on cortical oscillations. Finally, the modulation of GABA and gamma oscillations with repetitive TMS will be suggested as the possible mechanism through which rTMS exerts its therapeutic effects in the treatment of pain. The aim of this paper, therefore, is to present the TMS-EEG as a potential method through which to better classify, diagnose and treat chronic pain.
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Affiliation(s)
- Mera S Barr
- Schizophrenia Program, Centre for Addiction and Mental Health, 250 College Street, Toronto, Ontario, Canada M5T 1R8.
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17
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Andrade P, Visser-Vandewalle V, Del Rosario JS, Daemen MA, Buurman WA, Steinbusch HW, Hoogland G. The thalidomide analgesic effect is associated with differential TNF-α receptor expression in the dorsal horn of the spinal cord as studied in a rat model of neuropathic pain. Brain Res 2012; 1450:24-32. [PMID: 22425187 DOI: 10.1016/j.brainres.2012.02.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 01/29/2012] [Accepted: 02/14/2012] [Indexed: 01/30/2023]
Abstract
The proinflammatory cytokine tumor necrosis factor-α (TNF-α) is well recognized as a key player in nociceptive signaling. Yet, therapeutic capitalization of this knowledge requires a better understanding of how TNF receptors (TNFR) contribute to pain. To address this question, we studied TNFR expression in the chronic sciatic nerve constriction (CCI) model of neuropathic pain. CCI and sham operated rats received two subcutaneous injections (one immediately after surgery, the other on postoperative day 5) containing either saline, GABA-reuptake inhibitor (NO-711), insulin-like growth factor-1 (IGF-1), ZVAD or thalidomide. Mechanical (using von Frey filaments) and thermal hypersensitivity (Hargreaves test) were assessed preoperatively and weekly during the first four postoperative weeks. Spinal cord dorsal horn samples were collected from animals that were sacrificed at 2 weeks and 4 weeks after surgery, and analyzed for TNFR1 and TNFR2 mRNA levels by qPCR and protein levels by Western blot. Compared to saline, all applied drug treatments resulted in a faster recovery from mechanical and thermal hypersensitivity, yet in a potency order of thalidomide>ZVAD=IGF-1>NO-711. CCI resulted in increased TNFR1 and TNFR2 mRNA and protein levels in the ipsilateral dorsal horn. Thalidomide was the only treatment that attenuated these increases. Finally, animals that showed a poor behavioral recovery were characterized by a significantly higher TNFR1/TNFR2 mRNA ratio. These data show that differential expression of TNFR in the dorsal horn is associated with recovery from pain in this model and suggest that the analgesic effects of thalidomide may act via this mechanism.
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Affiliation(s)
- Pablo Andrade
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands.
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Janssen SP, Gerard S, Raijmakers ME, Truin M, Van Kleef M, Joosten EA. Decreased intracellular GABA levels contribute to spinal cord stimulation-induced analgesia in rats suffering from painful peripheral neuropathy: the role of KCC2 and GABA(A) receptor-mediated inhibition. Neurochem Int 2012; 60:21-30. [PMID: 22107704 DOI: 10.1016/j.neuint.2011.11.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 10/18/2011] [Accepted: 11/08/2011] [Indexed: 02/02/2023]
Abstract
Elevated spinal extracellular γ-aminobutyric acid (GABA) levels have been described during spinal cord stimulation (SCS)-induced analgesia in experimental chronic peripheral neuropathy. Interestingly, these increased GABA levels strongly exceeded the time frame of SCS-induced analgesia. In line with the former, pharmacologically-enhanced extracellular GABA levels by GABA(B) receptor agonists in combination with SCS in non-responders to SCS solely could convert these non-responders into responders. However, similar treatment with GABA(A) receptor agonists and SCS is known to be less efficient. Since K⁺ Cl⁻ cotransporter 2 (KCC2) functionality strongly determines proper GABA(A) receptor-mediated inhibition, both decreased numbers of GABA(A) receptors as well as reduced KCC2 protein expression might play a pivotal role in this loss of GABA(A) receptor-mediated inhibition in non-responders. Here, we explored the mechanisms underlying both changes in extracellular GABA levels and impaired GABA(A) receptor-mediated inhibition after 30 min of SCS in rats suffering from partial sciatic nerve ligation (PSNL). Immediately after cessation of SCS, a decreased spinal intracellular dorsal horn GABA-immunoreactivity was observed in responders when compared to non-responders or sham SCS rats. One hour later however, GABA-immunoreactivity was already increased to similar levels as those observed in non-responder or sham SCS rats. These changes did not coincide with alterations in the number of GABA-immunoreactive cells. C-Fos/GABA double-fluorescence clearly confirmed a SCS-induced activation of GABA-immunoreactive cells in responders immediately after SCS. Differences in spinal dorsal horn GABA(A) receptor-immunoreactivity and KCC2 protein levels were absent between all SCS groups. However, KCC2 protein levels were significantly decreased compared to sham PSNL animals. In conclusion, reduced intracellular GABA levels are only present during the time frame of SCS in responders and strongly point to a SCS-mediated on/off GABAergic release mechanism. Furthermore, a KCC2-dependent impaired GABA(A) receptor-mediated inhibition seems to be present both in responders and non-responders to SCS due to similar KCC2 and GABA(A) receptor levels.
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Affiliation(s)
- S P Janssen
- Pain Management and Research Center, Department of Anesthesiology, Maastricht University Medical Center, P. Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands.
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Taherianfard M, Mosavi M. Hippocampal GABA(A) Receptor and Pain Sensitivity during Estrous Cycle in the Rat. IRANIAN JOURNAL OF MEDICAL SCIENCES 2011; 36:289-95. [PMID: 23115414 PMCID: PMC3470277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Revised: 05/11/2011] [Accepted: 06/19/2011] [Indexed: 11/16/2022]
Abstract
BACKGROUND Estradiol and progesterone as well as hippocampal GABA(A) receptors are believed to play a role in the modulation of pain. The aim of present study was to investigate the effect of intrahippocampal injections of GABA(A) receptor agonist (muscimol) and GABA(A) receptor antagonist (picrotoxin) on pain sensitivity during estrous cycle. METHODS Pain sensitivity was evaluated in rats by formalin test during all stages of estrous cycle. Animals were divided into five groups including; 1- control (intact animal); 2- sham 1 receiving 0.75 µl artificial cerebrospinal fluids (ACSF); 3- sham 2 receiving 0.75 µl alcoholic ACSF; 4- experimental 1 receiving 250 or 500 µg/rat of muscimol in 0.75 µl vehicle, and 5- experimental 2 receiving 20 or 30 µg/rat picrotoxin in 0.75 µl vehicle. Data were analyzed by Kruskal-Wallis followed by Tucky's test for pairwise comparisons using a P value of ≤0.50 for statistical significance. RESULTS Muscimol significantly (P<0.05) decreased pain sensitivity in all stages of estrous cycle, and the analgesic effect was higher during proestrus and estrus stages of estrous cycle than that during metestrus and diestrus stages. Picrotoxin significantly (P<0.05) increased pain sensitivity in all stages of estrous cycle, and such a hyperalgesic effect was lower during proestrus and estrus stages of estrous cycle than that during metestrus and diestrus stages. CONCLUSION The findings of the present study indicate that the role of hippocampal GABA(A) receptor in the control of the pain sensitivity can be modulated by variation in gonadal steroids during different stages of the estrous cycle.
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Yin H, Yang EJ, Park SJ, Han SK. Glycine- and GABA-mimetic Actions of Shilajit on the Substantia Gelatinosa Neurons of the Trigeminal Subnucleus Caudalis in Mice. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2011; 15:285-9. [PMID: 22128261 DOI: 10.4196/kjpp.2011.15.5.285] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/10/2011] [Accepted: 10/10/2011] [Indexed: 11/15/2022]
Abstract
Shilajit, a medicine herb commonly used in Ayurveda, has been reported to contain at least 85 minerals in ionic form that act on a variety of chemical, biological, and physical stressors. The substantia gelatinosa (SG) neurons of the trigeminal subnucleus caudalis (Vc) are involved in orofacial nociceptive processing. Shilajit has been reported to be an injury and muscular pain reliever but there have been few functional studies of the effect of Shilajit on the SG neurons of the Vc. Therefore, whole cell and gramicidin-perfotrated patch clamp studies were performed to examine the action mechanism of Shilajit on the SG neurons of Vc from mouse brainstem slices. In the whole cell patch clamp mode, Shilajit induced short-lived and repeatable inward currents under the condition of a high chloride pipette solution on all the SG neurons tested. The Shilajit-induced inward currents were concentration dependent and maintained in the presence of tetrodotoxin (TTX), a voltage gated Na(+) channel blocker, CNQX, a non-NMDA glutamate receptor antagonist, and AP5, an NMDA receptor antagonist. The Shilajit-induced responses were partially suppressed by picrotoxin, a GABA(A) receptor antagonist, and totally blocked in the presence of strychnine, a glycine receptor antagonist, however not affected by mecamylamine hydrochloride (MCH), a nicotinic acetylcholine receptor antagonist. Under the potassium gluconate pipette solution at holding potential 0 mV, Shilajit induced repeatable outward current. These results show that Shilajit has inhibitory effects on the SG neurons of Vc through chloride ion channels by activation of the glycine receptor and GABA(A) receptor, indicating that Shilajit contains sedating ingredients for the central nervous system. These results also suggest that Shilajit may be a potential target for modulating orofacial pain processing.
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Affiliation(s)
- Hua Yin
- Department of Oral Physiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju 561-756, Korea
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Janssen SP, Truin M, Van Kleef M, Joosten EA. Differential GABAergic disinhibition during the development of painful peripheral neuropathy. Neuroscience 2011; 184:183-94. [PMID: 21496475 DOI: 10.1016/j.neuroscience.2011.03.060] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 03/25/2011] [Accepted: 03/26/2011] [Indexed: 11/27/2022]
Abstract
An impaired spinal GABAergic inhibitory function is known to be pivotal in neuropathic pain (NPP). At present, data concerning time-dependent alterations within the GABAergic system itself and post-synaptic GABA(A) receptor-mediated inhibitory transmission are highly controversial, likely related to the experimental NPP model used. Furthermore, it is unknown whether the severity of NPP is determined by the degree of these GABAergic disturbances. In the present study we therefore examined in one experimental animal model whether anatomical changes within the spinal GABAergic system and its GABA(A) receptor-mediated inhibitory function are gradually aggravated during the development of partial sciatic nerve injury (PSNL)-induced NPP and are related to the severity of PSNL-induced hypersensitivity. Three and 16 days after a unilateral PSNL (early and late NPP, respectively), GABA-immunoreactivity (GABA-IR) and the number of GABA-IR neuronal profiles were determined in Rexed laminae 1-3 of lumbar spinal cord cryosections. Additionally, the efficiency of dorsal horn GABA(A) receptor-induced inhibition was examined by cation chloride cotransporter 2 (KCC2) immunoblotting. NPP-induced hypersensitivity was only observed at the ipsilateral side, both at early and late time points. During early NPP, a decrease in ipsilateral dorsal horn GABA-IR was observed without alterations in the number of GABA-IR neuronal profiles or KCC2 protein levels. In contrast, bilateral increases in spinal GABA-IR accompanied by an unchanged number of GABA-IR interneurons were observed during late NPP. This was furthermore attended with decreased ipsilateral KCC2 levels. Moreover, the degree of hypersensitivity was not related to disturbances within the spinal GABAergic system at all time points examined. In conclusion, our anatomical data suggest that a dysfunctional GABA production is likely to be involved in early NPP whereas late NPP is characterized by a combined dysfunctional GABA release and decreased KCC2 levels, the latter suggesting an impaired GABA(A) receptor-mediated inhibition.
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Affiliation(s)
- S P Janssen
- Pain Management and Research Center, Department of Anesthesiology, Maastricht University Medical Center, P. Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, The Netherlands.
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