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Zhang H, Zhu Z, Ma WX, Kong LX, Yuan PC, Bu LF, Han J, Huang ZL, Wang YQ. The contribution of periaqueductal gray in the regulation of physiological and pathological behaviors. Front Neurosci 2024; 18:1380171. [PMID: 38650618 PMCID: PMC11034386 DOI: 10.3389/fnins.2024.1380171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 03/18/2024] [Indexed: 04/25/2024] Open
Abstract
Periaqueductal gray (PAG), an integration center for neuronal signals, is located in the midbrain and regulates multiple physiological and pathological behaviors, including pain, defensive and aggressive behaviors, anxiety and depression, cardiovascular response, respiration, and sleep-wake behaviors. Due to the different neuroanatomical connections and functional characteristics of the four functional columns of PAG, different subregions of PAG synergistically regulate various instinctual behaviors. In the current review, we summarized the role and possible neurobiological mechanism of different subregions of PAG in the regulation of pain, defensive and aggressive behaviors, anxiety, and depression from the perspective of the up-down neuronal circuits of PAG. Furthermore, we proposed the potential clinical applications of PAG. Knowledge of these aspects will give us a better understanding of the key role of PAG in physiological and pathological behaviors and provide directions for future clinical treatments.
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Affiliation(s)
- Hui Zhang
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Joint International Research Laboratory of Sleep, Fudan University, Shanghai, China
- Anhui Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Wannan Medical College, Wuhu, China
| | - Zhe Zhu
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Joint International Research Laboratory of Sleep, Fudan University, Shanghai, China
| | - Wei-Xiang Ma
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Joint International Research Laboratory of Sleep, Fudan University, Shanghai, China
| | - Ling-Xi Kong
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Joint International Research Laboratory of Sleep, Fudan University, Shanghai, China
| | - Ping-Chuan Yuan
- Anhui Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Wannan Medical College, Wuhu, China
| | - Li-Fang Bu
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Joint International Research Laboratory of Sleep, Fudan University, Shanghai, China
| | - Jun Han
- Anhui Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Wannan Medical College, Wuhu, China
| | - Zhi-Li Huang
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Joint International Research Laboratory of Sleep, Fudan University, Shanghai, China
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yi-Qun Wang
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Joint International Research Laboratory of Sleep, Fudan University, Shanghai, China
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Ho A, Lee SJ, Drew VJ, Jung J, Kang J, Cheong C, Kim T. Sleep disturbance correlated with severity of neuropathic pain in sciatic nerve crush injury model. J Sleep Res 2024:e14137. [PMID: 38199868 DOI: 10.1111/jsr.14137] [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: 08/26/2023] [Revised: 11/03/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024]
Abstract
The association between sleep and pain has been investigated widely. However, inconsistent results from animal studies compared with human data show the need for a validated animal model in the sleep-pain association field. Our study aims to validate common neuropathic pain models as a tool for evaluating the sleep-pain association. Electrodes electroencephalogram (EEG) and electromyogram (EMG) were surgically implanted to measure sleep. The von Frey test was used to measure pain sensitivity. Following the baseline data acquisition, two pain-modelling procedures were performed: sciatic nerve crush injury (SCI) and common peroneal nerve ligation (CPL). Post-injury measurements were performed on days 1, 5, 10, and 15 post-surgery. The results presented decreased paw withdrawal thresholds and reduced NREM sleep duration in both models on the first post-surgery day. In the SCI model, NREM sleep duration was negatively correlated with paw withdrawal thresholds (p = 0.0466), but not in the CPL model. Wake alpha and theta EEG powers were also correlated with the pain threshold. The results confirm that the SCI model shows disturbed sleep patterns associated with increased pain sensitivity, suggesting it is a reliable tool for investigating sleep disturbances associated with neuropathic pain.
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Affiliation(s)
- Anh Ho
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Sung-Jun Lee
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Victor J Drew
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Jieun Jung
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Jiseung Kang
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Chanyoung Cheong
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Tae Kim
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
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Su N, Cai P, Dou Z, Yin X, Xu H, He J, Li Z, Li C. Brain nuclei and neural circuits in neuropathic pain and brain modulation mechanisms of acupuncture: a review on animal-based experimental research. Front Neurosci 2023; 17:1243231. [PMID: 37712096 PMCID: PMC10498311 DOI: 10.3389/fnins.2023.1243231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/14/2023] [Indexed: 09/16/2023] Open
Abstract
Neuropathic pain (NP) is known to be associated with abnormal changes in specific brain regions, but the complex neural network behind it is vast and complex and lacks a systematic summary. With the help of various animal models of NP, a literature search on NP brain regions and circuits revealed that the related brain nuclei included the periaqueductal gray (PAG), lateral habenula (LHb), medial prefrontal cortex (mPFC), and anterior cingulate cortex (ACC); the related brain circuits included the PAG-LHb and mPFC-ACC. Moreover, acupuncture and injurious information can affect different brain regions and influence brain functions via multiple aspects to play an analgesic role and improve synaptic plasticity by regulating the morphology and structure of brain synapses and the expression of synapse-related proteins; maintain the balance of excitatory and inhibitory neurons by regulating the secretion of glutamate, γ-aminobutyric acid, 5-hydroxytryptamine, and other neurotransmitters and receptors in the brain tissues; inhibit the overactivation of glial cells and reduce the release of pro-inflammatory mediators such as interleukins to reduce neuroinflammation in brain regions; maintain homeostasis of glucose metabolism and regulate the metabolic connections in the brain; and play a role in analgesia through the mediation of signaling pathways and signal transduction molecules. These factors help to deepen the understanding of NP brain circuits and the brain mechanisms of acupuncture analgesia.
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Affiliation(s)
- Na Su
- First Clinical Medicine College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Pingping Cai
- Department of Traditional Chinese Medicine, Shandong Provincial Hospital, Jinan, China
| | - Zhiqiang Dou
- College of Acupuncture and Moxibustion and Tuina, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xiaoxue Yin
- Department of Science and Education, Shandong Academy of Chinese Medicine, Jinan, China
| | - Hongmin Xu
- Department of Gynecology, Laiwu Hospital of Traditional Chinese, Jinan, China
| | - Jing He
- First Clinical Medicine College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Zhaofeng Li
- College of Acupuncture and Moxibustion and Tuina, Shandong University of Traditional Chinese Medicine, Jinan, China
- International Office, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Changzhong Li
- Department of Obstetrics and Gynecology, Shenzhen Hospital, Peking University, Shenzhen, China
- Department of Gynecology, Shandong Provincial Hospital, Jinan, China
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Li X, Du ZJ, Xu JN, Liang ZM, Lin S, Chen H, Li SJ, Li XW, Yang JM, Gao TM. mGluR5 in hippocampal CA1 pyramidal neurons mediates stress-induced anxiety-like behavior. Neuropsychopharmacology 2023; 48:1164-1174. [PMID: 36797374 PMCID: PMC10267178 DOI: 10.1038/s41386-023-01548-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/18/2023] [Accepted: 02/06/2023] [Indexed: 02/18/2023]
Abstract
Pharmacological manipulation of mGluR5 has showed that mGluR5 is implicated in the pathophysiology of anxiety and mGluR5 has been proposed as a potential drug target for anxiety disorders. Nevertheless, the mechanism underlying the mGluR5 involvement in stress-induced anxiety-like behavior remains largely unknown. Here, we found that chronic restraint stress induced anxiety-like behavior and decreased the expression of mGluR5 in hippocampal CA1. Specific knockdown of mGluR5 in hippocampal CA1 pyramidal neurons produced anxiety-like behavior. Furthermore, both chronic restraint stress and mGluR5 knockdown impaired inhibitory synaptic inputs in hippocampal CA1 pyramidal neurons. Notably, positive allosteric modulator of mGluR5 rescued stress-induced anxiety-like behavior and restored the inhibitory synaptic inputs. These findings point to an essential role for mGluR5 in hippocampal CA1 pyramidal neurons in mediating stress-induced anxiety-like behavior.
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Affiliation(s)
- Xin Li
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Zhuo-Jun Du
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Jun-Nan Xu
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Zhi-Man Liang
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Song Lin
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Hao Chen
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Shu-Ji Li
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiao-Wen Li
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Jian-Ming Yang
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Tian-Ming Gao
- State Key Laboratory of Organ Failure Research, Institute of Brain Diseases, Nanfang Hospital, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
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Chen F, Zhang S, Li P, Xu K, Liu C, Geng B, Piao R, Liu P. Disruption of Periaqueductal Gray-default Mode Network Functional Connectivity in Patients with Crohn's Disease with Abdominal Pain. Neuroscience 2023; 517:96-104. [PMID: 36898497 DOI: 10.1016/j.neuroscience.2023.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/30/2023] [Accepted: 03/03/2023] [Indexed: 03/11/2023]
Abstract
Abdominal pain in Crohn's disease (CD) has been known to be associated with changes in the central nervous system. The periaqueductal gray (PAG) plays a well-established role in pain processing. However, the role of PAG-related network and the effect of pain on the network in CD remain unclear.Resting-state functional magnetic imaging (fMRI) data were collected from 24 CD patients in remission with abdominal pain, 24 CD patients without abdominal pain and 28 healthy controls (HCs). Using the subregions of PAG (dorsomedial (dmPAG), dorsolateral (dlPAG), lateral (lPAG) and ventrolateral (vlPAG)) as seeds, the seed-based FC maps were calculated and one-way analysis of variance (ANOVA) was performed to investigate the differences among the three groups.Results showed that the group differences were mainly involved in the FC of the vlPAG with the precuneus, medial prefrontal cortex (mPFC) as well as orbitofrontal cortex (OFC), and the FC of the right lateral PAG (lPAG) with the precuneus, inferior parietal lobule (IPL), angular gyrus and premotor cortex. The FC values of all these regions decreased successively in the order of HCs, CD without abdominal pain and CD with abdominal pain. The pain score was negatively correlated with the FC of the l/vlPAG with the precuneus, angular gyrus and mPFC in CD patients with abdominal pain.This study implicated the disrupt communication between the PAG and the default mode network (DMN). These findings complemented neuroimaging evidence for the pathophysiology of visceral pain in CD patients.
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Affiliation(s)
- Fenrong Chen
- Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University, No.157, Xi Wu Road, Xi'an 710003, China
| | - Shuming Zhang
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an 710071, China; Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710071, China; Engineering Research Center of Molecular and NeuroImaging, Ministry of Education, China
| | - Pengyu Li
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an 710071, China; Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710071, China; Engineering Research Center of Molecular and NeuroImaging, Ministry of Education, China
| | - Ke Xu
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an 710071, China; Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710071, China; Engineering Research Center of Molecular and NeuroImaging, Ministry of Education, China
| | - Chengxiang Liu
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an 710071, China; Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710071, China; Engineering Research Center of Molecular and NeuroImaging, Ministry of Education, China
| | - Bowen Geng
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an 710071, China; Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710071, China; Engineering Research Center of Molecular and NeuroImaging, Ministry of Education, China
| | - Ruiqing Piao
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an 710071, China; Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710071, China; Engineering Research Center of Molecular and NeuroImaging, Ministry of Education, China
| | - Peng Liu
- Life Science Research Center, School of Life Science and Technology, Xidian University, Xi'an 710071, China; Xi'an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710071, China; Engineering Research Center of Molecular and NeuroImaging, Ministry of Education, China.
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Light-Induced Activation of a Specific Type-5 Metabotropic Glutamate Receptor Antagonist in the Ventrobasal Thalamus Causes Analgesia in a Mouse Model of Breakthrough Cancer Pain. Int J Mol Sci 2022; 23:ijms23148018. [PMID: 35887364 PMCID: PMC9323585 DOI: 10.3390/ijms23148018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/29/2022] Open
Abstract
Breakthrough cancer pain (BTcP) refers to a sudden and transient exacerbation of pain, which develops in patients treated with opioid analgesics. Fast-onset analgesia is required for the treatment of BTcP. Light-activated drugs offer a novel potential strategy for the rapid control of pain without the typical adverse effects of systemic analgesic drugs. mGlu5 metabotropic glutamate receptor antagonists display potent analgesic activity, and light-induced activation of one of these compounds (JF-NP-26) in the thalamus was found to induce analgesia in models of inflammatory and neuropathic pain. We used an established mouse model of BTcP based on the injection of cancer cells into the femur, followed, 16 days later, by systemic administration of morphine. BTcP was induced by injection of endothelin-1 (ET-1) into the tumor, 20 min after morphine administration. Mice were implanted with optic fibers delivering light in the visible spectrum (405 nm) in the thalamus or prelimbic cortex to locally activate systemically injected JF-NP-26. Light delivery in the thalamus caused rapid and substantial analgesia, and this effect was specific because light delivery in the prelimbic cortex did not relieve BTcP. This finding lays the groundwork for the use of optopharmacology in the treatment of BTcP.
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Metabotropic Glutamate Receptor 5 in the Dysgranular Zone of Primary Somatosensory Cortex Mediates Neuropathic Pain in Rats. Biomedicines 2022; 10:biomedicines10071633. [PMID: 35884938 PMCID: PMC9313034 DOI: 10.3390/biomedicines10071633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 11/16/2022] Open
Abstract
The primary somatosensory cortex (S1) plays a key role in the discrimination of somatic sensations. Among subdivisions in S1, the dysgranular zone of rodent S1 (S1DZ) is homologous to Brodmann’s area 3a of primate S1, which is involved in the processing of noxious signals from the body. However, molecular changes in this region and their role in the pathological pain state have never been studied. In this study, we identified molecular alteration of the S1DZ in a rat model of neuropathic pain induced by right L5 spinal nerve ligation (SNL) surgery and investigated its functional role in pain symptoms. Brain images acquired from SNL group and control group in our previous study were analyzed, and behaviors were measured using the von Frey test, acetone test, and conditioned place preference test. We found that metabotropic glutamate receptor 5 (mGluR5) levels were significantly upregulated in the S1DZ contralateral to the nerve injury in the SNL group compared to the sham group. Pharmacological deactivation of mGluR5 in S1DZ ameliorated symptoms of neuropathic allodynia, which was shown by a significant increase in the mechanical paw withdrawal threshold and a decrease in the behavioral response to cold stimuli. We further confirmed that this treatment induced relief from the tonic-aversive state of chronic neuropathic pain, as a place preference memory associated with the treatment-paired chamber was formed in rats with neuropathic pain. Our data provide evidence that mGluR5 in the S1DZ is involved in the manifestation of abnormal pain sensations in the neuropathic pain state.
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Chung G, Kim SK. Therapeutics for Chemotherapy-Induced Peripheral Neuropathy: Approaches with Natural Compounds from Traditional Eastern Medicine. Pharmaceutics 2022; 14:pharmaceutics14071407. [PMID: 35890302 PMCID: PMC9319448 DOI: 10.3390/pharmaceutics14071407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/23/2022] [Accepted: 07/04/2022] [Indexed: 11/16/2022] Open
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) often develops in patients with cancer treated with commonly used anti-cancer drugs. The symptoms of CIPN can occur acutely during chemotherapy or emerge after cessation, and often accompany long-lasting intractable pain. This adverse side effect not only affects the quality of life but also limits the use of chemotherapy, leading to a reduction in the survival rate of patients with cancer. Currently, effective treatments for CIPN are limited, and various interventions are being applied by clinicians and patients because of the unmet clinical need. Potential approaches to ameliorate CIPN include traditional Eastern medicine-based methods. Medicinal substances from traditional Eastern medicine have well-established analgesic effects and are generally safe. Furthermore, many substances can also improve other comorbid symptoms in patients. This article aims to provide information regarding traditional Eastern medicine-based plant extracts and natural compounds for CIPN. In this regard, we briefly summarized the development, mechanisms, and changes in the nervous system related to CIPN, and reviewed the substances of traditional Eastern medicine that have been exploited to treat CIPN in preclinical and clinical settings.
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Affiliation(s)
- Geehoon Chung
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea;
| | - Sun Kwang Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea;
- Department of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea
- Correspondence:
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Neural Plasticity in the Brain during Neuropathic Pain. Biomedicines 2021; 9:biomedicines9060624. [PMID: 34072638 PMCID: PMC8228570 DOI: 10.3390/biomedicines9060624] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 01/02/2023] Open
Abstract
Neuropathic pain is an intractable chronic pain, caused by damage to the somatosensory nervous system. To date, treatment for neuropathic pain has limited effects. For the development of efficient therapeutic methods, it is essential to fully understand the pathological mechanisms of neuropathic pain. Besides abnormal sensitization in the periphery and spinal cord, accumulating evidence suggests that neural plasticity in the brain is also critical for the development and maintenance of this pain. Recent technological advances in the measurement and manipulation of neuronal activity allow us to understand maladaptive plastic changes in the brain during neuropathic pain more precisely and modulate brain activity to reverse pain states at the preclinical and clinical levels. In this review paper, we discuss the current understanding of pathological neural plasticity in the four pain-related brain areas: the primary somatosensory cortex, the anterior cingulate cortex, the periaqueductal gray, and the basal ganglia. We also discuss potential treatments for neuropathic pain based on the modulation of neural plasticity in these brain areas.
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