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Franciosa F, Acuña MA, Nevian NE, Nevian T. A cellular mechanism contributing to pain-induced analgesia. Pain 2024:00006396-990000000-00640. [PMID: 38968393 DOI: 10.1097/j.pain.0000000000003315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 03/27/2024] [Indexed: 07/07/2024]
Abstract
ABSTRACT The anterior cingulate cortex (ACC) plays a crucial role in the perception of pain. It is consistently activated by noxious stimuli and its hyperactivity in chronic pain indicates plasticity in the local neuronal network. However, the way persistent pain effects and modifies different neuronal cell types in the ACC and how this contributes to sensory sensitization is not completely understood. This study confirms the existence of 2 primary subtypes of pyramidal neurons in layer 5 of the rostral, agranular ACC, which we could classify as intratelencephalic (IT) and cortico-subcortical (SC) projecting neurons, similar to other cortical brain areas. Through retrograde labeling, whole-cell patch-clamp recording, and morphological analysis, we thoroughly characterized their different electrophysiological and morphological properties. When examining the effects of peripheral inflammatory pain on these neuronal subtypes, we observed time-dependent plastic changes in excitability. During the acute phase, both subtypes exhibited reduced excitability, which normalized to pre-inflammatory levels after day 7. Daily conditioning with nociceptive stimuli during this period induced an increase in excitability specifically in SC neurons, which was correlated with a decrease in mechanical sensitization. Subsequent inhibition of the activity of SC neurons projecting to the periaqueductal gray with in vivo chemogenetics, resulted in reinstatement of the hypersensitivity. Accordingly, it was sufficient to enhance the excitability of these neurons chemogenetically in the inflammatory pain condition to induce hypoalgesia. These findings suggest a cell type-specific effect on the descending control of nociception and a cellular mechanism for pain-induced analgesia. Furthermore, increased excitability in this neuronal population is hypoalgesic rather than hyperalgesic.
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Wang TZ, Wang F, Tian ZC, Li ZZ, Liu WN, Ding H, Xie TT, Cao ZX, Li HT, Sun ZC, Xie RG, Wu SX, Pan ZX, Luo C. Cingulate cGMP-dependent protein kinase I facilitates chronic pain and pain-related anxiety and depression. Pain 2023; 164:2447-2462. [PMID: 37326662 DOI: 10.1097/j.pain.0000000000002952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/25/2023] [Indexed: 06/17/2023]
Abstract
ABSTRACT Patients with chronic pain often experience exaggerated pain response and aversive emotion, such as anxiety and depression. Central plasticity in the anterior cingulate cortex (ACC) is assumed to be a critical interface for pain perception and emotion, which has been reported to involve activation of NMDA receptors. Numerous studies have documented the key significance of cGMP-dependent protein kinase I (PKG-I) as a crucial downstream target for the NMDA receptor-NO-cGMP signaling cascade in regulating neuronal plasticity and pain hypersensitivity in specific regions of pain pathway, ie, dorsal root ganglion or spinal dorsal horn. Despite this, whether and how PKG-I in the ACC contributes to cingulate plasticity and comorbidity of chronic pain and aversive emotion has remained elusive. Here, we uncovered a crucial role of cingulate PKG-I in chronic pain and comorbid anxiety and depression. Chronic pain caused by tissue inflammation or nerve injury led to upregulation of PKG-I expression at both mRNA and protein levels in the ACC. Knockdown of ACC-PKG-I relieved pain hypersensitivity as well as pain-associated anxiety and depression. Further mechanistic analysis revealed that PKG-I might act to phosphorylate TRPC3 and TRPC6, leading to enhancement of calcium influx and neuronal hyperexcitability as well as synaptic potentiation, which results in the exaggerated pain response and comorbid anxiety and depression. We believe this study sheds new light on the functional capability of ACC-PKG-I in modulating chronic pain as well as pain-associated anxiety and depression. Hence, cingulate PKG-I may represent a new therapeutic target against chronic pain and pain-related anxiety and depression.
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Affiliation(s)
- Tao-Zhi Wang
- Department of Anesthesiology, The Second Hospital of Jilin University, Jilin University, Changchun, China
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
| | - Fei Wang
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
- Medical Experiment Center, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Zhi-Cheng Tian
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Zhen-Zhen Li
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
| | - Wan-Neng Liu
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
- College of Life Sciences, Northwest University, Xi'an, China
| | - Hui Ding
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
| | - Ting-Ting Xie
- Department of Anesthesiology, The Second Hospital of Jilin University, Jilin University, Changchun, China
| | - Zi-Xuan Cao
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
- The Twenty-second Squadron of the Sixth Regiment, School of Basal Medicine, Fourth Military Medical University, Xi'an, China
| | - Hai-Tao Li
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
- The Fourteenth Squadron of the Fourth Regiment, School of Basal Medicine, Fourth Military Medical University, Xi'an, China
| | - Zhi-Chuan Sun
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
- Department of Neurosurgery, Xi'an Daxing Hospital, Xi'an, China
| | - Rou-Gang Xie
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
| | - Sheng-Xi Wu
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
| | - Zhen-Xiang Pan
- Department of Anesthesiology, The Second Hospital of Jilin University, Jilin University, Changchun, China
| | - Ceng Luo
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
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3
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Duan Y, Li Q, Zhou Y, Chen S, Li Y, Zang Y. Activation of the TNF-α-Necroptosis Pathway in Parvalbumin-Expressing Interneurons of the Anterior Cingulate Cortex Contributes to Neuropathic Pain. Int J Mol Sci 2023; 24:15454. [PMID: 37895135 PMCID: PMC10607712 DOI: 10.3390/ijms242015454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/19/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023] Open
Abstract
The hyperexcitability of the anterior cingulate cortex (ACC) has been implicated in the development of chronic pain. As one of the key causes of ACC hyperexcitation, disinhibition of the ACC may be closely related to the dysfunction of inhibitory parvalbumin (PV)-expressing interneurons (PV-INs). However, the molecular mechanism underlying the ACC PV-INs injury remains unclear. The present study demonstrates that spared sciatic nerve injury (SNI) induces an imbalance in the excitation and inhibition (E/I) of the ACC. To test whether tumor necrosis factor-α (TNF-α) upregulation in the ACC after SNI activates necroptosis and participates in PV-INs damage, we performed a differential analysis of transcriptome sequencing using data from neuropathic pain models and found that the expression of genes key to the TNF-α-necroptosis pathway were upregulated. TNF-α immunoreactivity (IR) signals in the ACCs of SNI rats were co-located with p-RIP3- and PV-IR, or p-MLKL- and PV-IR signals. We then systematically detected the expression and cell localization of necroptosis-related proteins, including kinase RIP1, RIP3, MLKL, and their phosphorylated states, in the ACC of SNI rats. Except for RIP1 and MLKL, the levels of these proteins were significantly elevated in the contralateral ACC and mainly expressed in PV-INs. Blocking the ACC TNF-α-necroptosis pathway by microinjecting TNF-α neutralizing antibody or using an siRNA knockdown to block expression of MLKL in the ACC alleviated SNI-induced pain hypersensitivity and inhibited the upregulation of TNF-α and p-MLKL. Targeting TNF-α-triggered necroptosis within ACC PV-INs may help to correct PV-INs injury and E/I imbalance in the ACC in neuropathic pain.
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Affiliation(s)
- Yiwen Duan
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Pain Research Center, Department of Physiology, Zhongshan Medical School, Sun Yat-Sen University, 74 Zhongshan Road 2, Guangzhou 510080, China; (Y.D.); (Q.L.); (Y.Z.); (Y.L.)
| | - Qiaoyun Li
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Pain Research Center, Department of Physiology, Zhongshan Medical School, Sun Yat-Sen University, 74 Zhongshan Road 2, Guangzhou 510080, China; (Y.D.); (Q.L.); (Y.Z.); (Y.L.)
| | - Yaohui Zhou
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Pain Research Center, Department of Physiology, Zhongshan Medical School, Sun Yat-Sen University, 74 Zhongshan Road 2, Guangzhou 510080, China; (Y.D.); (Q.L.); (Y.Z.); (Y.L.)
| | - Shaoxia Chen
- State Key Laboratory of Oncology in South China, Department of Anesthesiology, Sun Yat-Sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, 651 Dongfeng Road East, Guangzhou 510060, China;
| | - Yongyong Li
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Pain Research Center, Department of Physiology, Zhongshan Medical School, Sun Yat-Sen University, 74 Zhongshan Road 2, Guangzhou 510080, China; (Y.D.); (Q.L.); (Y.Z.); (Y.L.)
| | - Ying Zang
- Guangdong Provincial Key Laboratory of Brain Function and Disease, Pain Research Center, Department of Physiology, Zhongshan Medical School, Sun Yat-Sen University, 74 Zhongshan Road 2, Guangzhou 510080, China; (Y.D.); (Q.L.); (Y.Z.); (Y.L.)
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4
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Kawabata R, Yamanaka H, Kobayashi K, Oke Y, Fujita A, Oku Y, Yao I, Koga K. The anterior cingulate cortex is critical for acute stress-induced hypersensitivity in mice. Neuroscience 2023:S0306-4522(23)00221-X. [PMID: 37211084 DOI: 10.1016/j.neuroscience.2023.05.010] [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: 02/21/2023] [Revised: 05/04/2023] [Accepted: 05/14/2023] [Indexed: 05/23/2023]
Abstract
Stress can be categorized according to physical, psychological and social factors. Exposure to stress produces stress-induced hypersensitivity and forms negative emotions such as anxiety and depression. For example, acute physical stress induced by the elevated open platform (EOP) causes prolonged mechanical hypersensitivity. The anterior cingulate cortex (ACC) is a cortical region involved in pain and negative emotions. Recently, we showed that mice exposed to the EOP changed spontaneous excitatory, but not inhibitory transmission in layer II/III pyramidal neurons of the ACC. However, it is still unclear whether the ACC is involved in the EOP induced mechanical hypersensitivity, and how the EOP alters evoked synaptic transmission on excitatory and inhibitory synaptic transmission in the ACC. In this study, we injected ibotenic acid into the ACC to examine if it was involved in stress-induced mechanical hypersensitivity induced by EOP exposure. Next, by using whole-cell patch-clamp recording from brain slice preparation, we analyzed action potentials and evoked synaptic transmission from layer II/III pyramidal neurons within the ACC. Lesion of the ACC completely blocked the stress-induced mechanical hypersensitivity induced by EOP exposure. Mechanistically, EOP exposure mainly altered evoked excitatory postsynaptic currents such as input-output and paired pulse ratio. Intriguingly, the mice exposed in the EOP also produced low-frequency stimulation induced short-term depression on excitatory synapses in the ACC. These results suggest that the ACC plays a critical role in the modulation of stress-induced mechanical hypersensitivity, possibly through synaptic plasticity on excitatory transmission.
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Affiliation(s)
- Ryo Kawabata
- Biomedical Chemistry major, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan; Department of Neurophysiology, Faculty of Medicine, Hyogo Medical University, Nishinomiya, Hyogo 663-8501, Japan
| | - Hiroki Yamanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Hyogo Medical University, Nishinomiya, Hyogo 663-8501, Japan
| | - Kimiko Kobayashi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Hyogo Medical University, Nishinomiya, Hyogo 663-8501, Japan
| | - Yoshihiko Oke
- Department of Physiology, Faculty of Medicine, Hyogo Medical University, Nishinomiya, Hyogo 663-8501, Japan
| | - Ayumi Fujita
- Department of Neurophysiology, Faculty of Medicine, Hyogo Medical University, Nishinomiya, Hyogo 663-8501, Japan
| | - Yoshitaka Oku
- Department of Physiology, Faculty of Medicine, Hyogo Medical University, Nishinomiya, Hyogo 663-8501, Japan
| | - Ikuko Yao
- Biomedical Chemistry major, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
| | - Kohei Koga
- Department of Neurophysiology, Faculty of Medicine, Hyogo Medical University, Nishinomiya, Hyogo 663-8501, Japan.
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5
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Wei W, Yount ST, Allen ZD, Bechdol KF, Xia W, Mo H, Mabb AM. The mevalonate suppressor δ-tocotrienol increases AMPA receptor-mediated neurotransmission. Biochem Biophys Res Commun 2023; 638:112-119. [PMID: 36446153 DOI: 10.1016/j.bbrc.2022.11.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/07/2022] [Accepted: 11/17/2022] [Indexed: 11/21/2022]
Abstract
Synaptic dysfunction is a hallmark of aging and is found in several neurological disorders such as Alzheimer's disease. A common mechanism related to synaptic dysfunction is dysregulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, which mediate excitatory neurotransmission and synaptic plasticity. Accumulating evidence suggests that tocotrienols, vitamin E molecules that contain an isoprenoid side chain, may promote cognitive improvement in hippocampal-dependent learning tasks. Tocotrienols have also been shown to reduce the secretion of β-amyloid (Aβ) and cholesterol biosynthesis in part by downregulating 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme that controls flux of the mevalonate pathway and cholesterol biosynthesis. We hypothesized that tocotrienols might promote cognitive improvement by increasing AMPA receptor-mediated synaptic transmission. Here, we found that δ-tocotrienol increased surface levels of GluA1 but not the GluA2 AMPA receptor subunit in primary hippocampal neurons. Unexpectedly, δ-tocotrienol treatment caused a decrease in the phosphorylation of GluA1 at Serine 845 with no significant changes in GluA1 at Serine 831. Moreover, δ-tocotrienol increased spontaneous excitatory postsynaptic current (sEPSC) amplitude and reduced the secretion of Aβ40 in primary hippocampal neurons. Taken together, our findings suggest that δ-tocotrienol increases AMPA receptor-mediated neurotransmission via noncanonical changes in GluA1 phosphorylation status. These findings suggest that δ-tocotrienol may be beneficial in ameliorating synaptic dysfunction found in aging and neurological disease.
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Affiliation(s)
- Wei Wei
- Neuroscience Institute., Georgia State University, Atlanta, GA, United States
| | - Sophie T Yount
- Department of Chemistry, Georgia State University, Atlanta, GA, United States
| | - Zachary D Allen
- Neuroscience Institute., Georgia State University, Atlanta, GA, United States
| | - Katherine F Bechdol
- Department of Nutrition, Georgia State University, Atlanta, GA, United States
| | - Weiming Xia
- Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States; Geriatric Research Education and Clinic Center, Bedford VA Healthcare System, Bedford, MA, United States
| | - Huanbiao Mo
- Department of Nutrition, Georgia State University, Atlanta, GA, United States.
| | - Angela M Mabb
- Neuroscience Institute., Georgia State University, Atlanta, GA, United States; Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, United States.
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6
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Lee JHA, Chen Q, Zhuo M. Synaptic Plasticity in the Pain-Related Cingulate and Insular Cortex. Biomedicines 2022; 10:2745. [PMID: 36359264 PMCID: PMC9687873 DOI: 10.3390/biomedicines10112745] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/14/2022] [Accepted: 10/22/2022] [Indexed: 09/23/2023] Open
Abstract
Cumulative animal and human studies have consistently demonstrated that two major cortical regions in the brain, namely the anterior cingulate cortex (ACC) and insular cortex (IC), play critical roles in pain perception and chronic pain. Neuronal synapses in these cortical regions of adult animals are highly plastic and can undergo long-term potentiation (LTP), a phenomenon that is also reported in brain areas for learning and memory (such as the hippocampus). Genetic and pharmacological studies show that inhibiting such cortical LTP can help to reduce behavioral sensitization caused by injury as well as injury-induced emotional changes. In this review, we will summarize recent progress related to synaptic mechanisms for different forms of cortical LTP and their possible contribution to behavioral pain and emotional changes.
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Affiliation(s)
- Jung-Hyun Alex Lee
- Department of Physiology, Faculty of Medicine, University of Toronto, Medical Science Building, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
| | - Qiyu Chen
- Institute of Brain Research, Qingdao International Academician Park, Qingdao 266199, China
- Center for Neuron and Disease, Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China
| | - Min Zhuo
- Department of Physiology, Faculty of Medicine, University of Toronto, Medical Science Building, 1 King’s College Circle, Toronto, ON M5S 1A8, Canada
- Institute of Brain Research, Qingdao International Academician Park, Qingdao 266199, China
- Oujiang Laboratory, Zhejiang Lab for Regenerative Medicine, Vision and Brain Health, Wenzhou 325000, China
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7
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Mac KD, Qureshi MM, Na M, Chang S, Eom TJ, Je HS, Kim YR, Kwon HS, Chung E. Fast volumetric imaging with line-scan confocal microscopy by electrically tunable lens at resonant frequency. OPTICS EXPRESS 2022; 30:19152-19164. [PMID: 36221700 PMCID: PMC9363030 DOI: 10.1364/oe.450745] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 05/20/2023]
Abstract
In microscopic imaging of biological tissues, particularly real-time visualization of neuronal activities, rapid acquisition of volumetric images poses a prominent challenge. Typically, two-dimensional (2D) microscopy can be devised into an imaging system with 3D capability using any varifocal lens. Despite the conceptual simplicity, such an upgrade yet requires additional, complicated device components and usually suffers from a reduced acquisition rate, which is critical to properly document rapid neurophysiological dynamics. In this study, we implemented an electrically tunable lens (ETL) in the line-scan confocal microscopy (LSCM), enabling the volumetric acquisition at the rate of 20 frames per second with a maximum volume of interest of 315 × 315 × 80 µm3. The axial extent of point-spread-function (PSF) was 17.6 ± 1.6 µm and 90.4 ± 2.1 µm with the ETL operating in either stationary or resonant mode, respectively, revealing significant depth axial penetration by the resonant mode ETL microscopy. We further demonstrated the utilities of the ETL system by volume imaging of both cleared mouse brain ex vivo samples and in vivo brains. The current study showed a successful application of resonant ETL for constructing a high-performance 3D axially scanning LSCM (asLSCM) system. Such advances in rapid volumetric imaging would significantly enhance our understanding of various dynamic biological processes.
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Affiliation(s)
- Khuong Duy Mac
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | | | - Myeongsu Na
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, 03080 Seoul, Republic of Korea
| | - Sunghoe Chang
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, 03080 Seoul, Republic of Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, 03080 Seoul, Republic of Korea
| | - Tae Joong Eom
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea
- Engineering Research Center (ERC) for Color-modulated Extra-sensory Perception Technology, Pusan National University, Busan, 46241, Republic of Korea
| | - Hyunsoo Shawn Je
- Signature Program in Neuroscience and Behavioural Disorders, Duke-National University of Singapore (NUS) Medical School, 8 College Road 169857, Singapore
- Advanced Bioimaging Center, Academia, Ngee Ann Kongsi Discovery Tower Level 10, 20 College Road, 169855, Singapore
| | - Young Ro Kim
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
- Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Hyuk-Sang Kwon
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Euiheon Chung
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
- AI Graduate School, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
- Research Center for Photon Science Technology, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
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Zhu X, Xu Y, Shen Z, Zhang H, Xiao S, Zhu Y, Wu M, Chen Y, Wu Z, Xu Y, He X, Liu B, Liu J, Du J, Sun J, Fang J, Shao X. Rostral Anterior Cingulate Cortex–Ventrolateral Periaqueductal Gray Circuit Underlies Electroacupuncture to Alleviate Hyperalgesia but Not Anxiety-Like Behaviors in Mice With Spared Nerve Injury. Front Neurosci 2022; 15:757628. [PMID: 35095390 PMCID: PMC8789679 DOI: 10.3389/fnins.2021.757628] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 12/20/2021] [Indexed: 11/16/2022] Open
Abstract
Neuropathic pain is a common cause of chronic pain and is often accompanied by negative emotions, making it complex and difficult to treat. However, the neural circuit mechanisms underlying these symptoms remain unclear. Herein, we present a novel pathway associated with comorbid chronic pain and anxiety. Using chemogenetic methods, we found that activation of glutamatergic projections from the rostral anterior cingulate cortex (rACCGlu) to the ventrolateral periaqueductal gray (vlPAG) induced both hyperalgesia and anxiety-like behaviors in sham mice. Inhibition of the rACCGlu-vlPAG pathway reduced anxiety-like behaviors and hyperalgesia in the spared nerve injury (SNI) mice model; moreover, electroacupuncture (EA) effectively alleviated these symptoms. Investigation of the related mechanisms revealed that the chemogenetic activation of the rACCGlu-vlPAG circuit effectively blocked the analgesic effect of EA in the SNI mice model but did not affect the chronic pain-induced negative emotions. This study revealed a novel pathway, the rACCGlu-vlPAG pathway, that mediates neuropathic pain and pain-induced anxiety.
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9
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Transcranial Ultrasound Stimulation of the Anterior Cingulate Cortex Reduces Neuropathic Pain in Mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2021:6510383. [PMID: 35003307 PMCID: PMC8741380 DOI: 10.1155/2021/6510383] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 11/22/2021] [Indexed: 01/04/2023]
Abstract
Focused ultrasound (FUS) is a potential tool for treating chronic pain by modulating the central nervous system. Herein, we aimed to determine whether transcranial FUS stimulation of the anterior cingulate cortex (ACC) effectively improved chronic pain in the chronic compress injury mice model at different stages of neuropathic pain. The mechanical threshold of pain was recorded in the nociceptive tests. We found FUS stimulation elevated the mechanical threshold of pain in both short-term (p < 0.01) and long-term (p < 0.05) experiments. Furthermore, we determined protein expression differences in ACC between the control group, the intervention group, and the Sham group to analyze the underlying mechanism of FUS stimulation in improving neuropathic pain. Additionally, the results showed FUS stimulation led to alterations in differential proteins in long-term experiments, including cellular processes, cellular signaling, and information storage and processing. Our findings indicate FUS may effectively alleviate mechanical neuropathic pain via the ACC's stimulation, especially in the chronic state.
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10
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Toyoda H, Koga K. Nicotine Exposure during Adolescence Leads to Changes of Synaptic Plasticity and Intrinsic Excitability of Mice Insular Pyramidal Cells at Later Life. Int J Mol Sci 2021; 23:ijms23010034. [PMID: 35008455 PMCID: PMC8744609 DOI: 10.3390/ijms23010034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/19/2021] [Accepted: 12/20/2021] [Indexed: 11/16/2022] Open
Abstract
To find satisfactory treatment for nicotine addiction, synaptic and cellular mechanisms should be investigated comprehensively. Synaptic transmission, plasticity and intrinsic excitability in various brain regions are known to be altered by acute nicotine exposure. However, it has not been addressed whether and how nicotine exposure during adolescence alters these synaptic events and intrinsic excitability in the insular cortex in adulthood. To address this question, we performed whole-cell patch-clamp recordings to examine the effects of adolescent nicotine exposure on synaptic transmission, plasticity and intrinsic excitability in layer V pyramidal neurons (PNs) of the mice insular cortex five weeks after the treatment. We found that excitatory synaptic transmission and potentiation were enhanced in these neurons. Following adolescent nicotine exposure, insular layer V PNs displayed enhanced intrinsic excitability, which was reflected in changes in relationship between current strength and spike number, inter-spike interval, spike current threshold and refractory period. In addition, spike-timing precision evaluated by standard deviation of spike timing was decreased following nicotine exposure. Our data indicate that adolescent nicotine exposure enhances synaptic transmission, plasticity and intrinsic excitability in layer V PNs of the mice insular cortex at later life, which might contribute to severe nicotine dependence in adulthood.
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Affiliation(s)
- Hiroki Toyoda
- Department of Oral Physiology, Osaka University Graduate School of Dentistry, Suita 565-0871, Japan
- Correspondence:
| | - Kohei Koga
- Department of Neurophysiology, Hyogo College of Medicine, Nishinomiya 663-8501, Japan;
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11
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Seamans JK, Floresco SB. Event-based control of autonomic and emotional states by the anterior cingulate cortex. Neurosci Biobehav Rev 2021; 133:104503. [PMID: 34922986 DOI: 10.1016/j.neubiorev.2021.12.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 11/25/2021] [Accepted: 12/14/2021] [Indexed: 12/25/2022]
Abstract
Despite being an intensive area of research, the function of the anterior cingulate cortex (ACC) remains somewhat of a mystery. Human imaging studies implicate the ACC in various cognitive functions, yet surgical ACC lesions used to treat emotional disorders have minimal lasting effects on cognition. An alternative view is that ACC regulates autonomic states, consistent with its interconnectivity with autonomic control regions and that stimulation evokes changes in autonomic/emotional states. At the cellular level, ACC neurons are highly multi-modal and promiscuous, and can represent a staggering array of task events. These neurons nevertheless combine to produce highly event-specific ensemble patterns that likely alter activity in downstream regions controlling emotional and autonomic tone. Since neuromodulators regulate the strength of the ensemble activity patterns, they would regulate the impact these patterns have on downstream targets. Through these mechanisms, the ACC may determine how strongly to react to the very events its ensembles represent. Pathologies arise when specific event-related representations gain excessive control over autonomic/emotional states.
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Affiliation(s)
- Jeremy K Seamans
- Depts. of Psychiatry, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6B2T5, Canada.
| | - Stan B Floresco
- Depts. of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC, V6B2T5, Canada
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12
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Bak MS, Park H, Kim SK. Neural Plasticity in the Brain during Neuropathic Pain. Biomedicines 2021; 9:624. [PMID: 34072638 PMCID: PMC8228570 DOI: 10.3390/biomedicines9060624] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [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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Affiliation(s)
- Myeong Seong Bak
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea; (M.S.B.); (H.P.)
| | - Haney Park
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea; (M.S.B.); (H.P.)
| | - Sun Kwang Kim
- Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea; (M.S.B.); (H.P.)
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea
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13
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Correia Rocha IR, Chacur M. Modulatory effects of photobiomodulation in the anterior cingulate cortex of diabetic rats. Photochem Photobiol Sci 2021; 20:781-790. [PMID: 34053000 DOI: 10.1007/s43630-021-00059-1] [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: 03/12/2021] [Accepted: 05/25/2021] [Indexed: 10/21/2022]
Abstract
Anterior Cingulate Cortex (ACC) has a crucial contribution to higher order pain processing. Photobiomodulation (PBM) has being used as integrative medicine for pain treatment and for a variety of nervous system disorders. This study evaluated the effects of PBM in the ACC of diabetic rats. Type 1 diabetes was induced by a single dose of streptozotocin (85 mg/Kg). A total of ten sessions of PBM (pulsed gallium-arsenide laser, 904 nm, 9500 Hz, 6.23 J/cm2) was applied to the rat peripheral nervous system. Glial fibrillary acidic protein (GFAP), mu-opioid receptor (MOR), glutamate receptor 1 (GluR1), and glutamic acid decarboxylase (GAD65/67) protein level expression were analyzed in the ACC of diabetic rats treated with PBM. Our data revealed that PBM decreased 79.5% of GFAP protein levels in the ACC of STZ rats. Moreover, STZ + PBM rats had protein levels of MOR increased 14.7% in the ACC. Interestingly, STZ + PBM rats had a decrease in 70.7% of GluR1 protein level in the ACC. Additionally, PBM decreased 45.5% of GAD65/67 protein levels in the ACC of STZ rats.
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Affiliation(s)
- Igor Rafael Correia Rocha
- Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Avenue Lineu Prestes 2415, room 007, São Paulo, 05508-900, Brazil
| | - Marucia Chacur
- Departamento de Anatomia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Avenue Lineu Prestes 2415, room 007, São Paulo, 05508-900, Brazil.
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Nociceptor-localized cGMP-dependent protein kinase I is a critical generator for central sensitization and neuropathic pain. Pain 2021; 162:135-151. [PMID: 32773598 DOI: 10.1097/j.pain.0000000000002013] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Patients with neuropathic pain often experience exaggerated pain and anxiety. Central sensitization has been linked with the maintenance of neuropathic pain and may become an autonomous pain generator. Conversely, emerging evidence accumulated that central sensitization is initiated and maintained by ongoing nociceptive primary afferent inputs. However, it remains elusive what mechanisms underlie this phenomenon and which peripheral candidate contributes to central sensitization that accounts for pain hypersensitivity and pain-related anxiety. Previous studies have implicated peripherally localized cGMP-dependent protein kinase I (PKG-I) in plasticity of nociceptors and spinal synaptic transmission as well as inflammatory hyperalgesia. However, whether peripheral PKG-I contributes to cortical plasticity and hence maintains nerve injury-induced pain hypersensitivity and anxiety is unknown. Here, we demonstrated significant upregulation of PKG-I in ipsilateral L3 dorsal root ganglia (DRG), no change in L4 DRG, and downregulation in L5 DRG upon spared nerve injury. Genetic ablation of PKG-I specifically in nociceptors or post-treatment with intervertebral foramen injection of PKG-I antagonist, KT5823, attenuated the development and maintenance of spared nerve injury-induced bilateral pain hypersensitivity and anxiety. Mechanistic analysis revealed that activation of PKG-I in nociceptors is responsible for synaptic potentiation in the anterior cingulate cortex upon peripheral neuropathy through presynaptic mechanisms involving brain-derived neurotropic factor signaling. Our results revealed that PKG-I expressed in nociceptors is a key determinant for cingulate synaptic plasticity after nerve injury, which contributes to the maintenance of pain hypersensitivity and anxiety. Thereby, this study presents a strong basis for opening up a novel therapeutic target, PKG-I, in nociceptors for treatment of comorbidity of neuropathic pain and anxiety with least side effects.
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15
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Xiao X, Ding M, Zhang YQ. Role of the Anterior Cingulate Cortex in Translational Pain Research. Neurosci Bull 2021; 37:405-422. [PMID: 33566301 PMCID: PMC7954910 DOI: 10.1007/s12264-020-00615-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023] Open
Abstract
As the most common symptomatic reason to seek medical consultation, pain is a complex experience that has been classified into different categories and stages. In pain processing, noxious stimuli may activate the anterior cingulate cortex (ACC). But the function of ACC in the different pain conditions is not well discussed. In this review, we elaborate the commonalities and differences from accumulated evidence by a variety of pain assays for physiological pain and pathological pain including inflammatory pain, neuropathic pain, and cancer pain in the ACC, and discuss the cellular receptors and signaling molecules from animal studies. We further summarize the ACC as a new central neuromodulation target for invasive and non-invasive stimulation techniques in clinical pain management. The comprehensive understanding of pain processing in the ACC may lead to bridging the gap in translational research between basic and clinical studies and to develop new therapies.
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Affiliation(s)
- Xiao Xiao
- Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, Ministry of Education; Institute of Science and Technology for Brain-Inspired Intelligence, Behavioral and Cognitive Neuroscience Center, Fudan University, Shanghai, 200433, China.
| | - Ming Ding
- Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, Ministry of Education; Institute of Science and Technology for Brain-Inspired Intelligence, Behavioral and Cognitive Neuroscience Center, Fudan University, Shanghai, 200433, China
| | - Yu-Qiu Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Translational Neuroscience, Jing'an District Centre Hospital of Shanghai, Institutes of Brain Science; Institute of Integrative Medicine, Fudan University, Shanghai, 200032, China.
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16
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Zhang Y, Liu J, Wang X, Zhang J, Xie C. Extracellular vesicle-encapsulated microRNA-23a from dorsal root ganglia neurons binds to A20 and promotes inflammatory macrophage polarization following peripheral nerve injury. Aging (Albany NY) 2021; 13:6752-6764. [PMID: 33621204 PMCID: PMC7993670 DOI: 10.18632/aging.202532] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022]
Abstract
Extracellular vesicles (EVs) are capable of transferring microRNAs (miRNAs or miRs) between two different types of cells and also serve as vehicles for delivery of therapeutic molecules. After peripheral nerve injury, abnormal expression patterns of miRNAs have been observed in dorsal root ganglia (DRG) sensory neurons. We hypothesized that sensory neurons secrete miRs-containing EVs to communicate with macrophages. We demonstrated that miR-23a was upregulated in DRG neurons in spared nerve injury (SNI) mouse models. We also found that miR-23a was enriched in EVs released by cultured DRG neurons following capsaicin treatment. miR-23a-containing EVs were taken up into macrophages in which increased intracellular miR-23a promoted pro-inflammatory phenotype. A20 was verified as a target gene of miR-23a. Moreover, intrathecal delivery of EVs-miR-23a antagomir attenuated neuropathic hypersensitivity and reduced the number of M1 macrophages in injured DRGs by targeting A20. In conclusion, these results demonstrate that sensory neurons transfer EVs-encapsulated miR-23a to activate M1 macrophages and enhance neuropathic pain following the peripheral nerve injury. The study highlighted a new therapeutic approach to alleviate chronic neuropathic pain after nerve trauma by targeting detrimental miRNA in sensory neurons.
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Affiliation(s)
- Yamei Zhang
- Sichuan Medicine Key Laboratory of Clinical Genetics/Central Laboratory, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| | - Junying Liu
- Sichuan Medicine Key Laboratory of Clinical Genetics/Central Laboratory, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| | - Xin Wang
- Sichuan Medicine Key Laboratory of Clinical Genetics/Central Laboratory, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| | - Jinfeng Zhang
- Department of Pediatrics, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
| | - Chenchen Xie
- Department of Neurology, Affiliated Hospital of Chengdu University, Chengdu 610081, P.R. China
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17
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Seamans JK. The anterior cingulate cortex and event-based modulation of autonomic states. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2021; 158:135-169. [PMID: 33785144 DOI: 10.1016/bs.irn.2020.11.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In spite of being an intensive area of research focus, the anterior cingulate cortex (ACC) remains somewhat of an enigma. Many theories have focused on its role in various aspects of cognition yet surgically precise lesions of the ACC, used to treat severe emotional disorders in human patients, typically have no lasting effects on cognition. An alternative view is that the ACC has a prominent role in regulating autonomic states. This view is consistent with anatomical data showing that a main target of the ACC are regions involved in autonomic control and with the observation that stimulation of the ACC evokes changes in autonomic states in both animals and humans. From an electrophysiological perspective, ACC neurons appear able to represent virtually any event or internal state, even though there is not always a strong link between these representations and behavior. Ensembles of neurons form robust contextual representations that strongly influence how specific events are encoded. The activity patterns associated with these contextually-based event representations presumably impact activity in downstream regions that control autonomic state. As a result, the ACC may regulate the autonomic and perhaps emotional reactions to events it is representing. This event-based control of autonomic tone by the ACC would likely arise during all types of cognitive and affective processes, without necessarily being critical for any of them.
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Affiliation(s)
- Jeremy K Seamans
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada.
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18
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Duan H, Shen F, Li L, Tu Z, Chen P, Chen P, Wang Z, Liang W, Wang Y. Activation of the Notch signaling pathway in the anterior cingulate cortex is involved in the pathological process of neuropathic pain. Pain 2021; 162:263-274. [PMID: 32701650 PMCID: PMC7737863 DOI: 10.1097/j.pain.0000000000002014] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 07/01/2020] [Accepted: 07/13/2020] [Indexed: 12/29/2022]
Abstract
Plastic changes in the anterior cingulate cortex (ACC) are critical in pain hypersensitivity caused by peripheral nerves injury. The Notch signaling pathway has been shown to regulate synaptic differentiation and transmission. Therefore, this study was to investigate the function of the Notch signaling pathway in the ACC during nociceptive transmission induced by neuropathic pain. We adopted Western blotting, N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT) microinjections, RNA interference targeting Notch1, Hairy and enhancer of split (Hes) 1 or Hes5, electrophysiological recordings, and behavioral tests to verify the link between Notch signaling in ACC and neuropathic pain with adult male Sprague-Dawley rats. Levels of the Notch intracellular domain were increased in ACC on day 7 after chronic constriction injury surgery or spared nerve injury. Meanwhile, the mRNA level of the downstream effector of Notch signaling Hes1 was increased, whereas the level of Hes5 mRNA did not change. Microinjection of DAPT, a γ-secretase (a key enzyme involved in Notch pathway) inhibitor, into ACC significantly reversed neuropathic pain behaviors. Intra-ACC injection of short hairpin RNA-Notch reduced Notch intracellular domain expression and decreased the potentiation of synaptic transmission in the ACC. Moreover, pain perceptions were also alleviated in rats subjected to chronic constriction injury or spared nerve injury. This process was mainly mediated by the downstream effector Hes1, but not Hes5. Based on these results, the activation of the Notch/Hes1 signaling pathway in the ACC participates in the development of neuropathic pain, indicating that the Notch pathway may be a new therapeutic target for treating chronic pain.
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Affiliation(s)
- Haifeng Duan
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Fengyan Shen
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Li Li
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhiyi Tu
- Department of Anesthesiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Ping Chen
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Pei Chen
- Department of Anesthesiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Zhiru Wang
- Key Laboratory of Brain Functional Genomics-Ministry of Education, School of Life Science, East China Normal University, Shanghai, China
| | - Weimin Liang
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai, China
| | - Yingwei Wang
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai, China
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Kummer KK, Mitrić M, Kalpachidou T, Kress M. The Medial Prefrontal Cortex as a Central Hub for Mental Comorbidities Associated with Chronic Pain. Int J Mol Sci 2020; 21:E3440. [PMID: 32414089 PMCID: PMC7279227 DOI: 10.3390/ijms21103440] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/06/2020] [Accepted: 05/07/2020] [Indexed: 12/13/2022] Open
Abstract
Chronic pain patients frequently develop and suffer from mental comorbidities such as depressive mood, impaired cognition, and other significant constraints of daily life, which can only insufficiently be overcome by medication. The emotional and cognitive components of pain are processed by the medial prefrontal cortex, which comprises the anterior cingulate cortex, the prelimbic, and the infralimbic cortex. All three subregions are significantly affected by chronic pain: magnetic resonance imaging has revealed gray matter loss in all these areas in chronic pain conditions. While the anterior cingulate cortex appears hyperactive, prelimbic, and infralimbic regions show reduced activity. The medial prefrontal cortex receives ascending, nociceptive input, but also exerts important top-down control of pain sensation: its projections are the main cortical input of the periaqueductal gray, which is part of the descending inhibitory pain control system at the spinal level. A multitude of neurotransmitter systems contributes to the fine-tuning of the local circuitry, of which cholinergic and GABAergic signaling are particularly emerging as relevant components of affective pain processing within the prefrontal cortex. Accordingly, factors such as distraction, positive mood, and anticipation of pain relief such as placebo can ameliorate pain by affecting mPFC function, making this cortical area a promising target region for medical as well as psychosocial interventions for pain therapy.
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Affiliation(s)
| | | | | | - Michaela Kress
- Institute of Physiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.K.K.); (M.M.); (T.K.)
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20
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Meng XL, Fu P, Wang L, Yang X, Hong G, Zhao X, Lao J. Increased EZH2 Levels in Anterior Cingulate Cortex Microglia Aggravate Neuropathic Pain by Inhibiting Autophagy Following Brachial Plexus Avulsion in Rats. Neurosci Bull 2020; 36:793-805. [PMID: 32346844 DOI: 10.1007/s12264-020-00502-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 01/07/2020] [Indexed: 12/19/2022] Open
Abstract
After brachial plexus avulsion (BPA), microglia induce inflammation, initiating and maintaining neuropathic pain. EZH2 (enhancer of zeste homolog 2) has been implicated in inflammation and neuropathic pain, but the mechanisms by which it regulates neuropathic pain remain unclear. Here, we found that EZH2 levels were markedly upregulated during BPA-induced neuropathic pain in vivo and in vitro, stimulating pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6) secretion in vivo. In rats with BPA-induced neuropathic pain, mechanical and cold hypersensitivities were induced by EZH2 upregulation and inhibited by EZH2 downregulation in the anterior cingulate cortex. Microglial autophagy was also significantly inhibited, with EZH2 inhibition activating autophagy and reducing neuroinflammation in vivo. However, this effect was impaired by inhibiting autophagy with 3-methyladenine, suggesting that the MTOR signaling pathway is a functional target of EZH2. These data suggest that EZH2 regulates neuroinflammation and neuropathic pain via a novel MTOR-mediated autophagy signaling pathway, providing a promising approach for managing neuropathic pain.
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Affiliation(s)
- Xiang-Lei Meng
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, 200032, China
- Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, 200032, China
| | - Pengfei Fu
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Lin Wang
- Health Management Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450001, China
| | - Xun Yang
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, 200032, China
- Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, 200032, China
| | - Guanghui Hong
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, 200032, China
- Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, 200032, China
| | - Xin Zhao
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, 200040, China
- Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, 200032, China
- Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, 200032, China
| | - Jie Lao
- Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, 200040, China.
- Key Laboratory of Hand Reconstruction, Ministry of Health, Shanghai, 200032, China.
- Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, 200032, China.
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Chai Z, Ma C, Jin X. Homeostatic activity regulation as a mechanism underlying the effect of brain stimulation. Bioelectron Med 2019; 5:16. [PMID: 32232105 PMCID: PMC7098242 DOI: 10.1186/s42234-019-0032-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/23/2019] [Indexed: 01/10/2023] Open
Abstract
Hyperexcitability of the neural network often occurs after brain injuries or degeneration and is a key pathophysiological feature in certain neurological diseases such as epilepsy, neuropathic pain, and tinnitus. Although the standard approach of pharmacological treatments is to directly suppress the hyperexcitability through reducing excitation or enhancing inhibition, different techniques for stimulating brain activity are often used to treat refractory neurological conditions. However, it is unclear why stimulating brain activity would be effective for controlling hyperexcitability. Recent studies suggest that the pathogenesis in these disorders exhibits a transition from an initial activity loss after acute injury or progressive neurodegeneration to subsequent development of hyperexcitability. This process mimics homeostatic activity regulation and may contribute to developing network hyperexcitability that underlies neurological symptoms. This hypothesis also predicts that stimulating brain activity should be effective in reducing hyperexcitability due to homeostatic activity regulation and in relieving symptoms. Here we review current evidence of homeostatic plasticity in the development of hyperexcitability in some neurological diseases and the effects of brain stimulation. The homeostatic plasticity hypothesis may provide new insights into the pathophysiology of neurological diseases and may guide the use of brain stimulation techniques for treating them.
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Affiliation(s)
- Zhi Chai
- Neurobiology Research Center, College of Basic Medicine, Shanxi University of Chinese Medicine, Taiyuan, 030619 China
| | - Cungen Ma
- Neurobiology Research Center, College of Basic Medicine, Shanxi University of Chinese Medicine, Taiyuan, 030619 China
| | - Xiaoming Jin
- Department of Anatomy, Cell Biology and Physiology, Department of Neurological Surgery, Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 West 15th Street, NB 500C, Indianapolis, IN 46202 USA
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