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Wu H, Xie L, Chen Q, Xu F, Dai A, Ma X, Xie S, Li H, Zhu F, Jiao C, Sun L, Xu Q, Zhou Y, Shen Y, Chen X. Activation of GABAergic neurons in the dorsal raphe nucleus alleviates hyperalgesia induced by ovarian hormone withdrawal. Pain 2024:00006396-990000000-00678. [PMID: 39106454 DOI: 10.1097/j.pain.0000000000003362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 06/25/2024] [Indexed: 08/09/2024]
Abstract
ABSTRACT Menopausal and postmenopausal women, characterized by a significant reduction in ovarian hormones, have a high prevalence of chronic pain with great pain intensity. However, the underlying mechanism of hyperalgesia induced by ovarian hormone withdrawal remains poorly understood. Here, we report that decreases in the activity and excitability of GABAergic neurons in the dorsal raphe nucleus (DRN) are associated with hyperalgesia induced by ovariectomy in mice. Supplementation with 17β-estradiol, but not progesterone, is sufficient to increase the mechanical pain threshold in ovariectomized (OVX) mice and the excitability of DRN GABAergic (DRNGABA) neurons. Moreover, activation of the DRNGABA neurons projecting to the lateral parabrachial nucleus was critical for alleviating hyperalgesia in OVX mice. These findings show the essential role of DRNGABA neurons and their modulation by estrogen in regulating hyperalgesia induced by ovarian hormone withdrawal, providing therapeutic basis for the treatment of chronic pain in physiological or surgical menopausal women.
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Affiliation(s)
- Hui Wu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Linghua Xie
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qing Chen
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Fang Xu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ange Dai
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaolin Ma
- School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Shulan Xie
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hua Li
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Fangfang Zhu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Cuicui Jiao
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lihong Sun
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qi Xu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yudong Zhou
- School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Yi Shen
- School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Xinzhong Chen
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
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2
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Obray JD, Wilkes ET, Scofield MD, Chandler LJ. Adolescent alcohol exposure promotes mechanical allodynia and alters synaptic function at inputs from the basolateral amygdala to the prelimbic cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599360. [PMID: 38948749 PMCID: PMC11212875 DOI: 10.1101/2024.06.17.599360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Binge drinking is common among adolescents despite mounting evidence linking it to various adverse health outcomes that include heightened pain perception. The prelimbic (PrL) cortex is vulnerable to insult from adolescent alcohol exposure and receives input from the basolateral amygdala (BLA) while sending projections to the ventrolateral periaqueductal gray (vlPAG) - two brain regions implicated in nociception. In this study, adolescent intermittent ethanol (AIE) exposure was carried out in male and female rats using a vapor inhalation procedure. Assessments of mechanical and thermal sensitivity revealed that AIE exposure induced protracted mechanical allodynia. To investigate synaptic function at BLA inputs onto defined populations of PrL neurons, retrobeads and viral labelling were combined with optogenetics and slice electrophysiology. Recordings from retrobead labelled cells in the PrL revealed AIE reduced BLA driven feedforward inhibition of neurons projecting from the PrL to the vlPAG, resulting in augmented excitation/inhibition (E/I) balance and increased intrinsic excitability. Consistent with this finding, recordings from virally tagged PrL parvalbumin interneurons (PVINs) demonstrated that AIE exposure reduced both E/I balance at BLA inputs onto PVINs and PVIN intrinsic excitability. These findings provide compelling evidence that AIE alters synaptic function and intrinsic excitability within a prefrontal nociceptive circuit.
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Affiliation(s)
- J. Daniel Obray
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425
| | - Erik T. Wilkes
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425
| | - Michael D. Scofield
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC, 29425
| | - L. Judson Chandler
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425
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3
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Zhang Y, Ma H, Bai Y, Hou X, Yang Y, Wang G, Li Y. Chronic Neuropathic Pain and Comorbid Depression Syndrome: From Neural Circuit Mechanisms to Treatment. ACS Chem Neurosci 2024; 15:2432-2444. [PMID: 38916052 DOI: 10.1021/acschemneuro.4c00125] [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] [Indexed: 06/26/2024] Open
Abstract
Chronic neuropathic pain and comorbid depression syndrome (CDS) is a major worldwide health problem that affects the quality of life of patients and imposes a tremendous socioeconomic burden. More than half of patients with chronic neuropathic pain also suffer from moderate or severe depression. Due to the complex pathogenesis of CDS, there are no effective therapeutic drugs available. The lack of research on the neural circuit mechanisms of CDS limits the development of treatments. The purpose of this article is to provide an overview of the various circuits involved in CDS. Notably, activating some neural circuits can alleviate pain and/or depression, while activating other circuits can exacerbate these conditions. Moreover, we discuss current and emerging pharmacotherapies for CDS, such as ketamine. Understanding the circuit mechanisms of CDS may provide clues for the development of novel drug treatments for improved CDS management.
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Affiliation(s)
- Yue Zhang
- Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Hui Ma
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Yafan Bai
- Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Xiaojuan Hou
- Hebei North University, Zhangjiakou, 075000, China
| | - Yixin Yang
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Guyan Wang
- Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Yunfeng Li
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
- Beijing Institute of Pharmacology and Toxicology, State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing, 100850, China
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4
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Harding EK, Zhang Z, Canet-Pons J, Stokes-Heck S, Trang T, Zamponi GW. Expression of GAD2 in excitatory neurons projecting from the ventrolateral periaqueductal gray to the locus coeruleus. iScience 2024; 27:109972. [PMID: 38868198 PMCID: PMC11166693 DOI: 10.1016/j.isci.2024.109972] [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: 12/01/2023] [Revised: 01/12/2024] [Accepted: 05/10/2024] [Indexed: 06/14/2024] Open
Abstract
The ventrolateral periaqueductal gray (vlPAG) functionally projects to diverse brain regions, including the locus coeruleus (LC). Excitatory projections from the vlPAG to the LC are well described, while few studies have indicated the possibility of inhibitory projections. Here, we quantified the relative proportion of excitatory and inhibitory vlPAG-LC projections in male and female mice, and found an unexpected overlapping population of neurons expressing both GAD2 and VGLUT2. Combined in vitro optogenetic stimulation and electrophysiology of LC neurons revealed that vlPAG neurons expressing channelrhodopsin-2 under the GAD2 promoter release both GABA and glutamate. Subsequent experiments identified a population of GAD2+/VGLUT2+ vlPAG neurons exclusively releasing glutamate onto LC neurons. Altogether, we demonstrate that ∼25% of vlPAG-LC projections are inhibitory, and that there is a significant GAD2 expressing population of glutamatergic projections. Our findings have broad implications for the utility of GAD2-Cre lines within midbrain and brainstem regions, and especially within the PAG.
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Affiliation(s)
- Erika K. Harding
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB T2N 4N1, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Zizhen Zhang
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Julia Canet-Pons
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Sierra Stokes-Heck
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Tuan Trang
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Gerald W. Zamponi
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
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Viellard J, Bouali-Benazzouz R, Benazzouz A, Fossat P. Modulating Neural Circuits of Pain in Preclinical Models: Recent Insights for Future Therapeutics. Cells 2024; 13:997. [PMID: 38920628 PMCID: PMC11202162 DOI: 10.3390/cells13120997] [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: 05/06/2024] [Revised: 06/05/2024] [Accepted: 06/06/2024] [Indexed: 06/27/2024] Open
Abstract
Chronic pain is a pathological state defined as daily pain sensation over three consecutive months. It affects up to 30% of the general population. Although significant research efforts have been made in the past 30 years, only a few and relatively low effective molecules have emerged to treat chronic pain, with a considerable translational failure rate. Most preclinical models have focused on sensory neurotransmission, with particular emphasis on the dorsal horn of the spinal cord as the first relay of nociceptive information. Beyond impaired nociceptive transmission, chronic pain is also accompanied by numerous comorbidities, such as anxiety-depressive disorders, anhedonia and motor and cognitive deficits gathered under the term "pain matrix". The emergence of cutting-edge techniques assessing specific neuronal circuits allow in-depth studies of the connections between "pain matrix" circuits and behavioural outputs. Pain behaviours are assessed not only by reflex-induced responses but also by various or more complex behaviours in order to obtain the most complete picture of an animal's pain state. This review summarises the latest findings on pain modulation by brain component of the pain matrix and proposes new opportunities to unravel the mechanisms of chronic pain.
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Affiliation(s)
- Juliette Viellard
- Université de Bordeaux, UMR 5293, F-33076 Bordeaux, France
- CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France
| | - Rabia Bouali-Benazzouz
- Université de Bordeaux, UMR 5293, F-33076 Bordeaux, France
- CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France
| | - Abdelhamid Benazzouz
- Université de Bordeaux, UMR 5293, F-33076 Bordeaux, France
- CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France
| | - Pascal Fossat
- Université de Bordeaux, UMR 5293, F-33076 Bordeaux, France
- CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France
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6
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De Preter CC, Heinricher MM. The 'in's and out's' of descending pain modulation from the rostral ventromedial medulla. Trends Neurosci 2024; 47:447-460. [PMID: 38749825 PMCID: PMC11168876 DOI: 10.1016/j.tins.2024.04.006] [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: 01/24/2024] [Revised: 04/12/2024] [Accepted: 04/21/2024] [Indexed: 06/14/2024]
Abstract
The descending-pain modulating circuit controls the experience of pain by modulating transmission of sensory signals through the dorsal horn. This circuit's key output node, the rostral ventromedial medulla (RVM), integrates 'top-down' and 'bottom-up' inputs that regulate functionally defined RVM cell types, 'OFF-cells' and 'ON-cells', which respectively suppress or facilitate pain-related sensory processing. While recent advances have sought molecular definition of RVM cell types, conflicting behavioral findings highlight challenges involved in aligning functional and molecularly defined types. This review summarizes current understanding, derived primarily from rodent studies but with corroborating evidence from human imaging, of the role of RVM populations in pain modulation and persistent pain states and explores recent advances outlining inputs to, and outputs from, RVM pain-modulating neurons.
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Affiliation(s)
- Caitlynn C De Preter
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA; Department of Neurological Surgery, Oregon Health & Science University, Portland, OR 97239, USA
| | - Mary M Heinricher
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA; Department of Neurological Surgery, Oregon Health & Science University, Portland, OR 97239, USA.
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7
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Chen Q, Zhao M, Dong J, Yang K. Chronic restraint stress-induced hyperalgesia is modulated by the periaqueductal gray neurons projecting to the rostral ventromedial medulla in mice. Biochem Biophys Res Commun 2024; 710:149875. [PMID: 38604073 DOI: 10.1016/j.bbrc.2024.149875] [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: 03/09/2024] [Accepted: 03/29/2024] [Indexed: 04/13/2024]
Abstract
Stress-induced hyperalgesia (SIH) is induced by repeated or chronic exposure to stressful or uncomfortable environments. However, the neural mechanisms involved in the modulatory effects of the periaqueductal gray (PAG) and its associated loops on SIH development hav e not been elucidated. In the present study, we used chronic restraint stress (CRS)-induced hyperalgesia as a SIH model and manipulated neuronal activity via a pharmacogenetic approach to investigate the neural mechanism underlying the effects of descending pain-modulatory pathways on SIH. We found that activation of PAG neurons alleviates CRS-induced hyperalgesia; on the other hand, PAG neurons inhibition facilitates CRS-induced hyperalgesia. Moreover, this modulatory effect is achieved by the neurons which projecting to the rostral ventromedial medulla (RVM). Our data thus reveal the functional role of the PAG-RVM circuit in SIH and provide analgesic targets in the brain for clinical SIH treatment.
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Affiliation(s)
- Qian Chen
- Department of Anatomy, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Mingwei Zhao
- Department of Anatomy, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China
| | - Jiaxue Dong
- Department of Anatomy, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China; Department of Pathology, Xinyang Central Hospital, Xinyang, Henan, 464099, China
| | - Kun Yang
- Department of Anatomy, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, 212013, China; Department of Anatomy, School of Health and Life Sciences, University of Health and Rehabilitation Sciences, Qingdao, Shandong, 266113, China.
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8
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Lubejko ST, Livrizzi G, Buczynski SA, Patel J, Yung JC, Yaksh TL, Banghart MR. Inputs to the locus coeruleus from the periaqueductal gray and rostroventral medulla shape opioid-mediated descending pain modulation. SCIENCE ADVANCES 2024; 10:eadj9581. [PMID: 38669335 PMCID: PMC11051679 DOI: 10.1126/sciadv.adj9581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 03/26/2024] [Indexed: 04/28/2024]
Abstract
The supraspinal descending pain modulatory system (DPMS) shapes pain perception via monoaminergic modulation of sensory information in the spinal cord. However, the role and synaptic mechanisms of descending noradrenergic signaling remain unclear. Here, we establish that noradrenergic neurons of the locus coeruleus (LC) are essential for supraspinal opioid antinociception. While much previous work has emphasized the role of descending serotonergic pathways, we find that opioid antinociception is primarily driven by excitatory output from the ventrolateral periaqueductal gray (vlPAG) to the LC. Furthermore, we identify a previously unknown opioid-sensitive inhibitory input from the rostroventromedial medulla (RVM), the suppression of which disinhibits LC neurons to drive spinal noradrenergic antinociception. We describe pain-related activity throughout this circuit and report the presence of prominent bifurcating outputs from the vlPAG to the LC and the RVM. Our findings substantially revise current models of the DPMS and establish a supraspinal antinociceptive pathway that may contribute to multiple forms of descending pain modulation.
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Affiliation(s)
- Susan T. Lubejko
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Giulia Livrizzi
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Biological Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stanley A. Buczynski
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
- Chemistry and Biochemistry Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Janki Patel
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jean C. Yung
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Tony L. Yaksh
- Departments of Anesthesiology and Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Matthew R. Banghart
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
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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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10
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Kaneko T, Oura A, Imai Y, Kusumoto-Yoshida I, Kanekura T, Okuno H, Kuwaki T, Kashiwadani H. Orexin neurons play contrasting roles in itch and pain neural processing via projecting to the periaqueductal gray. Commun Biol 2024; 7:290. [PMID: 38459114 PMCID: PMC10923787 DOI: 10.1038/s42003-024-05997-x] [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: 08/04/2023] [Accepted: 02/28/2024] [Indexed: 03/10/2024] Open
Abstract
Pain and itch are recognized as antagonistically regulated sensations; pain suppresses itch, whilst pain inhibition enhances itch. The neural mechanisms at the central nervous system (CNS) underlying these pain-itch interactions still need to be explored. Here, we revealed the contrasting role of orexin-producing neurons (ORX neurons) in the lateral hypothalamus (LH), which suppresses pain while enhancing itch neural processing, by applying optogenetics to the acute pruritus and pain model. We also revealed that the circuit of ORX neurons from LH to periaqueductal gray regions served in the contrasting modulation of itch and pain processing using optogenetic terminal inhibition techniques. Additionally, by using an atopic dermatitis model, we confirmed the involvement of ORX neurons in regulating chronic itch processing, which could lead to a novel therapeutic target for persistent pruritus in clinical settings. Our findings provide new insight into the mechanism of antagonistic regulation between pain and itch in the CNS.
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Affiliation(s)
- Tatsuroh Kaneko
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
| | - Asuka Oura
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yoshiki Imai
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Ikue Kusumoto-Yoshida
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Takuro Kanekura
- Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Hiroyuki Okuno
- Laboratory of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Tomoyuki Kuwaki
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Hideki Kashiwadani
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
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11
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Costa AR, Tavares I, Martins I. How do opioids control pain circuits in the brainstem during opioid-induced disorders and in chronic pain? Implications for the treatment of chronic pain. Pain 2024; 165:324-336. [PMID: 37578500 DOI: 10.1097/j.pain.0000000000003026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 07/07/2023] [Indexed: 08/15/2023]
Abstract
ABSTRACT Brainstem areas involved in descending pain modulation are crucial for the analgesic actions of opioids. However, the role of opioids in these areas during tolerance, opioid-induced hyperalgesia (OIH), and in chronic pain settings remains underappreciated. We conducted a revision of the recent studies performed in the main brainstem areas devoted to descending pain modulation with a special focus on the medullary dorsal reticular nucleus (DRt), as a distinctive pain facilitatory area and a key player in the diffuse noxious inhibitory control paradigm. We show that maladaptive processes within the signaling of the µ-opioid receptor (MOR), which entail desensitization and a switch to excitatory signaling, occur in the brainstem, contributing to tolerance and OIH. In the context of chronic pain, the alterations found are complex and depend on the area and model of chronic pain. For example, the downregulation of MOR and δ-opioid receptor (DOR) in some areas, including the DRt, during neuropathic pain likely contributes to the inefficacy of opioids. However, the upregulation of MOR and DOR, at the rostral ventromedial medulla, in inflammatory pain models, suggests therapeutic avenues to explore. Mechanistically, the rationale for the diversity and complexity of alterations in the brainstem is likely provided by the alternative splicing of opioid receptors and the heteromerization of MOR. In conclusion, this review emphasizes how important it is to consider the effects of opioids at these circuits when using opioids for the treatment of chronic pain and for the development of safer and effective opioids.
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Affiliation(s)
- Ana Rita Costa
- Department of Biomedicine, Unit of Experimental Biology, Faculty of Medicine, University of Porto, Porto, Portugal
- IBMC-Institute of Molecular and Cell Biology, University of Porto, Porto, Portugal
- I3S- Institute of Investigation and Innovation in Health, University of Porto, Porto, Portugal. Costa is now with the Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden and Science for Life Laboratory, Solna, Sweden
| | - Isaura Tavares
- Department of Biomedicine, Unit of Experimental Biology, Faculty of Medicine, University of Porto, Porto, Portugal
- IBMC-Institute of Molecular and Cell Biology, University of Porto, Porto, Portugal
- I3S- Institute of Investigation and Innovation in Health, University of Porto, Porto, Portugal. Costa is now with the Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden and Science for Life Laboratory, Solna, Sweden
| | - Isabel Martins
- Department of Biomedicine, Unit of Experimental Biology, Faculty of Medicine, University of Porto, Porto, Portugal
- IBMC-Institute of Molecular and Cell Biology, University of Porto, Porto, Portugal
- I3S- Institute of Investigation and Innovation in Health, University of Porto, Porto, Portugal. Costa is now with the Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden and Science for Life Laboratory, Solna, Sweden
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12
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Torres-Rodriguez JM, Wilson TD, Singh S, Torruella-Suárez ML, Chaudhry S, Adke AP, Becker JJ, Neugebauer B, Lin JL, Martinez Gonzalez S, Soler-Cedeño O, Carrasquillo Y. The parabrachial to central amygdala pathway is critical to injury-induced pain sensitization in mice. Neuropsychopharmacology 2024; 49:508-520. [PMID: 37542159 PMCID: PMC10789863 DOI: 10.1038/s41386-023-01673-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/27/2023] [Accepted: 07/12/2023] [Indexed: 08/06/2023]
Abstract
The spino-ponto-amygdaloid pathway is a major ascending circuit relaying nociceptive information from the spinal cord to the brain. Potentiation of excitatory synaptic transmission in the parabrachial nucleus (PBN) to central amygdala (CeA) pathway has been reported in rodent models of persistent pain. However, the functional significance of this pathway in the modulation of the somatosensory component of pain was recently challenged by studies showing that spinal nociceptive neurons do not target CeA-projecting PBN cells and that manipulations of this pathway have no effect on reflexive-defensive somatosensory responses to peripheral noxious stimulation. Here, we showed that activation of CeA-projecting PBN neurons is critical to increase both stimulus-evoked and spontaneous nociceptive responses following an injury in male and female mice. Using optogenetic-assisted circuit mapping, we confirmed a functional excitatory projection from PBN→CeA that is independent of the genetic or firing identity of CeA cells. We then showed that peripheral noxious stimulation increased the expression of the neuronal activity marker Fos in CeA-projecting PBN neurons and that chemogenetic inactivation of these cells decreased behavioral hypersensitivity in models of neuropathic and inflammatory pain without affecting baseline nociception. Lastly, we showed that chemogenetic activation of CeA-projecting PBN neurons is sufficient to induced bilateral hypersensitivity without injury. Together, our results indicate that the PBN→CeA pathway is a key modulator of pain-related behaviors that can increase reflexive-defensive and affective-motivational responses to somatosensory stimulation in injured states without affecting nociception under normal physiological conditions.
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Affiliation(s)
- Jeitzel M Torres-Rodriguez
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Torri D Wilson
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Sudhuman Singh
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Maria L Torruella-Suárez
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Sarah Chaudhry
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Anisha P Adke
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Jordan J Becker
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Benjamin Neugebauer
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Jenny L Lin
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Santiago Martinez Gonzalez
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Omar Soler-Cedeño
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Yarimar Carrasquillo
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA.
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA.
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13
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Nguyen KT, Beauchamp DW, O'Hara RB. A Pathophysiological Approach for Selecting Medications to Treat Nociceptive and Neuropathic Pain in Servicemembers. Mil Med 2024:usad506. [PMID: 38300182 DOI: 10.1093/milmed/usad506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 09/12/2023] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
INTRODUCTION The prevalence of chronic pain of service members (SMs) in the U.S. is estimated to be higher (roughly 31-44%) compared to that of civilian population (26%). This higher prevalence is likely due to the high physical demands related combat and training injuries that are not immediately resolved and worsen over time. Mental Health America reports that chronic pain can lead to other mental health conditions such as severe anxiety, depression, bipolar disorder, and post-traumatic stress disorder. Such mental health conditions can negatively affect job performance, reduce readiness for military duties, and often lead to patterns of misuse of opioid after SMs entering civilian life. The primary objective of this narrative review is to present a summarized guideline for the treatment of two types of pain that likely affect SMs, namely nociceptive somatic pain and neuropathic pain. This review focused on a stepwise approach starting with nonopioid interventions prior to opioid therapy. The secondary objective of this review is to elucidate the primary mechanisms of action and pathways associated with these two types of pain. METHODS We followed the Scale for Assessment of Narrative Review Articles when transcribing this narrative review article to enhance the quality and brevity of this review. This Scale has 0.77% an intra-class coefficient of correlation, 95% confidence interval and 0.88 inter-rater reliability. We searched PubMed, Google Scholar, WorldCAT, and the Cochrane Library for the primary and secondary articles that targeted mechanisms of action, pathways, and pharmacological modalities for nociceptive somatic and neuropathic pain that were published from 2011 to 2022. We excluded articles related to pediatric, some specific pain conditions such as cancer-related pain, palliative care, end-of-life care, and articles that were not written in English language. For pharmacologic selection, we adopted the guidelines from the Policy for Implementation of a Comprehensive Policy on Pain Management by the Military Health Care system for the Fiscal Year 2021; the Clinical Practice Guidance for Opioid Therapy for Chronic Pain by the Department of Defense/Veterans Health Administration (2022); the (2021) Implementation of a Comprehensive Policy on Pain Management by the Military Health Care System; and the (2022) Guideline for Prescribing Opioids for Chronic Painby the Centers for Disease Control. DISCUSSION From the knowledge of the mechanisms of action and pathways, we can be more likely to identify the causative origins of pain. As a result, we can correctly diagnose the type of pain, properly develop an efficient and personalized treatment plan, minimize adverse effects, and optimize clinical outcomes. The guideline, however, does not serve as a substitute for clinical judgment in patient-centered decision-making. Medication choices should be individualized judiciously based on the patient's comorbid conditions, available social and economic resources, and the patient's preferences to balance the benefits and risks associated with various pain medications and to achieve optimal pain relief and improve the patient's quality of life.
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Affiliation(s)
- Khan Thi Nguyen
- Interdisciplinary Pain Management Clinic, William Beaumont Army Medical Center, Fort Bliss, TX 79918, USA
| | - Daniel W Beauchamp
- Interdisciplinary Pain Management Clinic, William Beaumont Army Medical Center, Fort Bliss, TX 79918, USA
| | - Reginald B O'Hara
- Department of Clinical Investigation, William Beaumont Army Medical Center, Fort Bliss, TX 79918, USA
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14
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Brewer CL, Kauer JA. Low-Frequency Stimulation of Trpv1-Lineage Peripheral Afferents Potentiates the Excitability of Spino-Periaqueductal Gray Projection Neurons. J Neurosci 2024; 44:e1184232023. [PMID: 38050062 PMCID: PMC10860615 DOI: 10.1523/jneurosci.1184-23.2023] [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: 06/26/2023] [Revised: 10/19/2023] [Accepted: 11/09/2023] [Indexed: 12/06/2023] Open
Abstract
High-threshold dorsal root ganglion (HT DRG) neurons fire at low frequencies during inflammatory injury, and low-frequency stimulation (LFS) of HT DRG neurons selectively potentiates excitatory synapses onto spinal neurons projecting to the periaqueductal gray (spino-PAG). Here, in male and female mice, we have identified an underlying peripheral sensory population driving this plasticity and its effects on the output of spino-PAG neurons. We provide the first evidence that Trpv1-lineage sensory neurons predominantly induce burst firing, a unique mode of neuronal activity, in lamina I spino-PAG projection neurons. We modeled inflammatory injury by optogenetically stimulating Trpv1+ primary afferents at 2 Hz for 2 min (LFS), as peripheral inflammation induces 1-2 Hz firing in high-threshold C fibers. LFS of Trpv1+ afferents enhanced the synaptically evoked and intrinsic excitability of spino-PAG projection neurons, eliciting a stable increase in the number of action potentials (APs) within a Trpv1+ fiber-induced burst, while decreasing the intrinsic AP threshold and increasing the membrane resistance. Further experiments revealed that this plasticity required Trpv1+ afferent input, postsynaptic G protein-coupled signaling, and NMDA receptor activation. Intriguingly, an inflammatory injury and heat exposure in vivo also increased APs per burst, in vitro These results suggest that inflammatory injury-mediated plasticity is driven though Trpv1+ DRG neurons and amplifies the spino-PAG pathway. Spinal inputs to the PAG could play an integral role in its modulation of heat sensation during peripheral inflammation, warranting further exploration of the organization and function of these neural pathways.
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Affiliation(s)
- Chelsie L Brewer
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California 94305
| | - Julie A Kauer
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California 94305
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15
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Jin P, Cui F, Zhang L. Altered metabolites in the periaqueductal gray of COVID-19 patients experiencing headaches: a longitudinal MRS study. Front Neurol 2024; 14:1323290. [PMID: 38249726 PMCID: PMC10796602 DOI: 10.3389/fneur.2023.1323290] [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: 10/17/2023] [Accepted: 12/15/2023] [Indexed: 01/23/2024] Open
Abstract
Background Headache is one of the most common symptoms of acute COVID-19 infection. However, its mechanisms remain poorly understood, and there is a lack of studies investigating changes in the periaqueductal gray (PAG) in COVID-19 patients exhibiting headaches. Purpose The study aimed to explore the alterations in metabolites of the PAG pre- and post-COVID-19 infection in individuals who suffered from headaches during the acute phase of the disease using proton magnetic resonance spectroscopy (1H-MRS). Methods Fifteen participants who experienced headaches during the acute phase of COVID-19 were recruited. All subjects underwent two proton magnetic resonance spectroscopy (1H-MRS) examinations focusing on the PAG before and after they were infected. Metabolite changes were assessed between the pre- and post-infection groups. Results The combined glutamine and glutamate/total creatine ratio (Glx/tCr) was increased in the PAG following COVID-19 infection. The total choline/total creatine ratio (tCho/tCr) in the pre-infection group was negatively correlated with the duration of headache during the COVID-19 acute phase. Conclusion The present study indicates that PAG plays a pivotal role in COVID-19 headaches, thereby supporting the involvement of trigeminovascular system activation in the pathophysiology of COVID-19 headaches.
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Affiliation(s)
| | | | - Luping Zhang
- Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, Zhejiang Province, China
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16
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Coizet V, Al Tannir R, Pautrat A, Overton PG. Separation of Channels Subserving Approach and Avoidance/Escape at the Level of the Basal Ganglia and Related Brainstem Structures. Curr Neuropharmacol 2024; 22:1473-1490. [PMID: 37594168 PMCID: PMC11097992 DOI: 10.2174/1570159x21666230818154903] [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: 12/09/2022] [Revised: 03/23/2023] [Accepted: 03/29/2023] [Indexed: 08/19/2023] Open
Abstract
The basal ganglia have the key function of directing our behavior in the context of events from our environment and/or our internal state. This function relies on afferents targeting the main input structures of the basal ganglia, entering bids for action selection at the level of the striatum or signals for behavioral interruption at the level of the subthalamic nucleus, with behavioral reselection facilitated by dopamine signaling. Numerous experiments have studied action selection in relation to inputs from the cerebral cortex. However, less is known about the anatomical and functional link between the basal ganglia and the brainstem. In this review, we describe how brainstem structures also project to the main input structures of the basal ganglia, namely the striatum, the subthalamic nucleus and midbrain dopaminergic neurons, in the context of approach and avoidance (including escape from threat), two fundamental, mutually exclusive behavioral choices in an animal's repertoire in which the brainstem is strongly involved. We focus on three particularly well-described loci involved in approach and avoidance, namely the superior colliculus, the parabrachial nucleus and the periaqueductal grey nucleus. We consider what is known about how these structures are related to the basal ganglia, focusing on their projections toward the striatum, dopaminergic neurons and subthalamic nucleus, and explore the functional consequences of those interactions.
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Affiliation(s)
- Véronique Coizet
- Grenoble Institute of Neuroscience, University Grenoble Alpes, Bâtiment E.J. Safra - Chemin Fortuné Ferrini - 38700 La Tronche France;
| | - Racha Al Tannir
- Grenoble Institute of Neuroscience, University Grenoble Alpes, Bâtiment E.J. Safra - Chemin Fortuné Ferrini - 38700 La Tronche France;
| | - Arnaud Pautrat
- Grenoble Institute of Neuroscience, University Grenoble Alpes, Bâtiment E.J. Safra - Chemin Fortuné Ferrini - 38700 La Tronche France;
| | - Paul G. Overton
- Department of Psychology, University of Sheffield, Sheffield, United Kingdom
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17
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Wang Q, Li Z, Nie D, Mu X, Wang Y, Jiang Y, Zhang Y, Lu Z. Low-frequency electroacupuncture exerts antinociceptive effects through activation of POMC neural circuit induced endorphinergic input to the periaqueductal gray from the arcuate nucleus. Mol Pain 2024; 20:17448069241254201. [PMID: 38670551 PMCID: PMC11102703 DOI: 10.1177/17448069241254201] [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: 02/18/2024] [Revised: 03/12/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
It has been widely recognized that electroacupuncture (EA) inducing the release of β-endorphin represents a crucial mechanism of EA analgesia. The arcuate nucleus (ARC) in the hypothalamus is a vital component of the endogenous opioid peptide system. Serving as an integration center, the periaqueductal gray (PAG) receives neural fiber projections from the frontal cortex, insular cortex, and ARC. However, the specific mechanisms how EA facilitates the release of β-endorphin within the ARC, eliciting analgesic effects are yet to be elucidated. In this study, we conducted in vivo and in vitro experiments by transcriptomics, microdialysis, photogenetics, chemical genetics, and calcium imaging, combined with transgenic animals. Firstly, we detected 2 Hz EA at the Zusanli (ST36) increased the level of β-endorphin and transcriptional level of proopiomelanocortin (POMC). Our transcriptomics profiling demonstrated that 2 Hz EA at the ST36 modulates the expression of c-Fos and Jun B in ARC brain nuclear cluster, and the transcriptional regulation of 2 Hz EA mainly occur in POMC neurons by Immunofluorescence staining verification. Meaning while, 2 Hz EA specifically activated the cAMP-PKA-CREB signaling pathway in ARC which mediating the c-Fos and Jun B transcription, and 2 Hz EA analgesia is dependent on the activation of cAMP-PKA-CREB signaling pathway in ARC. In order to investigate how the β-endorphin produced in ARC transfer to integration center PAG, transneuronal tracing technology was used to observe the 2 Hz EA promoted the neural projection from ARC to PAG compared to 100 Hz EA and sham mice. Inhibited PAGGABA neurons, the transfer of β-endorphin from the ARC nucleus to the PAG nucleus through the ARCPOMC-PAGGABA neural circuit. Furthermore, by manipulating the excitability of POMC neurons from ARCPOMC to PAGGABA using inhibitory chemogenetics and optogenetics, we found that this inhibition significantly reduced transfer of β-endorphin from the ARC nucleus to the PAG nucleus and the effectiveness of 2 Hz EA analgesia in neurological POMC cyclization recombination enzyme (Cre) mice and C57BL/6J mice, which indicates that the transfer of β-endorphin depends on the activation of POMC neurons prefect from ARCPOMC to PAGGABA. These findings contribute to our understanding of the neural circuitry underlying the EA pain-relieving effects and maybe provide valuable insights for optimizing EA stimulation parameters in clinical pain treatment using the in vivo dynamic visual investigating the central analgesic mechanism.
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Affiliation(s)
- Qian Wang
- Shandong University of Traditional Chinese Medicine, Nanjing, China
| | - Zhonghao Li
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing, China
- School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
- School of Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Dengyun Nie
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
- School of Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xinru Mu
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
- School of Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yuxuan Wang
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
- School of Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yongwei Jiang
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yongchen Zhang
- Shandong University of Traditional Chinese Medicine, Nanjing, China
| | - Zhigang Lu
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
- School of Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
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18
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Yao D, Chen Y, Chen G. The role of pain modulation pathway and related brain regions in pain. Rev Neurosci 2023; 34:899-914. [PMID: 37288945 DOI: 10.1515/revneuro-2023-0037] [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: 03/25/2023] [Accepted: 05/18/2023] [Indexed: 06/09/2023]
Abstract
Pain is a multifaceted process that encompasses unpleasant sensory and emotional experiences. The essence of the pain process is aversion, or perceived negative emotion. Central sensitization plays a significant role in initiating and perpetuating of chronic pain. Melzack proposed the concept of the "pain matrix", in which brain regions associated with pain form an interconnected network, rather than being controlled by a singular brain region. This review aims to investigate distinct brain regions involved in pain and their interconnections. In addition, it also sheds light on the reciprocal connectivity between the ascending and descending pathways that participate in pain modulation. We review the involvement of various brain areas during pain and focus on understanding the connections among them, which can contribute to a better understanding of pain mechanisms and provide opportunities for further research on therapies for improved pain management.
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Affiliation(s)
- Dandan Yao
- Department of Anesthesiology, School of Medicine, Shaoxing University, Shaoxing, Zhejiang, China
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yeru Chen
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Gang Chen
- Department of Anesthesiology, School of Medicine, Shaoxing University, Shaoxing, Zhejiang, China
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
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19
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Sullere S, Kunczt A, McGehee DS. A cholinergic circuit that relieves pain despite opioid tolerance. Neuron 2023; 111:3414-3434.e15. [PMID: 37734381 PMCID: PMC10843525 DOI: 10.1016/j.neuron.2023.08.017] [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: 01/18/2023] [Revised: 04/19/2023] [Accepted: 08/16/2023] [Indexed: 09/23/2023]
Abstract
Chronic pain is a tremendous burden for afflicted individuals and society. Although opioids effectively relieve pain, significant adverse outcomes limit their utility and efficacy. To investigate alternate pain control mechanisms, we explored cholinergic signaling in the ventrolateral periaqueductal gray (vlPAG), a critical nexus for descending pain modulation. Biosensor assays revealed that pain states decreased acetylcholine release in vlPAG. Activation of cholinergic projections from the pedunculopontine tegmentum to vlPAG relieved pain, even in opioid-tolerant conditions, through ⍺7 nicotinic acetylcholine receptors (nAChRs). Activating ⍺7 nAChRs with agonists or stimulating endogenous acetylcholine inhibited vlPAG neuronal activity through Ca2+ and peroxisome proliferator-activated receptor α (PPAR⍺)-dependent signaling. In vivo 2-photon imaging revealed that chronic pain induces aberrant excitability of vlPAG neuronal ensembles and that ⍺7 nAChR-mediated inhibition of these cells relieves pain, even after opioid tolerance. Finally, pain relief through these cholinergic mechanisms was not associated with tolerance, reward, or withdrawal symptoms, highlighting its potential clinical relevance.
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Affiliation(s)
- Shivang Sullere
- Committee on Neurobiology, University of Chicago, Chicago, IL 60637, USA
| | - Alissa Kunczt
- Department of Anesthesia and Critical Care, University of Chicago, Chicago, IL 60637, USA
| | - Daniel S McGehee
- Committee on Neurobiology, University of Chicago, Chicago, IL 60637, USA; Department of Anesthesia and Critical Care, University of Chicago, Chicago, IL 60637, USA.
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20
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Lubejko ST, Livrizzi G, Patel J, Yung JC, Yaksh TL, Banghart MR. Inputs to the locus coeruleus from the periaqueductal gray and rostroventral medulla shape opioid-mediated descending pain modulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.10.561768. [PMID: 37873091 PMCID: PMC10592708 DOI: 10.1101/2023.10.10.561768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The supraspinal descending pain modulatory system (DPMS) shapes pain perception via monoaminergic modulation of sensory information in the spinal cord. However, the role and synaptic mechanisms of descending noradrenergic signaling remain unclear. Here, we establish that noradrenergic neurons of the locus coeruleus (LC) are essential for supraspinal opioid antinociception. Unexpectedly, given prior emphasis on descending serotonergic pathways, we find that opioid antinociception is primarily driven by excitatory output from the ventrolateral periaqueductal gray (vlPAG) to the LC. Furthermore, we identify a previously unknown opioid-sensitive inhibitory input from the rostroventromedial medulla (RVM), the suppression of which disinhibits LC neurons to drive spinal noradrenergic antinociception. We also report the presence of prominent bifurcating outputs from the vlPAG to the LC and the RVM. Our findings significantly revise current models of the DPMS and establish a novel supraspinal antinociceptive pathway that may contribute to multiple forms of descending pain modulation.
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Affiliation(s)
- Susan T. Lubejko
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Giulia Livrizzi
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
- Biological Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Janki Patel
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Jean C. Yung
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Tony L. Yaksh
- Departments of Anesthesiology and Pharmacology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Matthew R. Banghart
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
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21
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Li J, Peng S, Zhang Y, Ge J, Gao S, Zhu Y, Bai Y, Wu S, Huang J. Glutamatergic Neurons in the Zona Incerta Modulate Pain and Itch Behaviors in Mice. Mol Neurobiol 2023; 60:5866-5877. [PMID: 37354250 DOI: 10.1007/s12035-023-03431-7] [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: 02/16/2023] [Accepted: 06/05/2023] [Indexed: 06/26/2023]
Abstract
Emerging evidence suggest that parvalbumin neurons in zona incerta (ZI) modulate pain and itch behavior in opposite manners. However, the role of ZI glutamatergic neurons, a unique incertal neuronal subpopulation residing in the caudal division, in pain and itch modulation remains unknown. In the present study, by combining chemogenetic manipulation, fiber photometry, and behavioral tests, we proved that incertal glutamatergic neurons served as an endogenous negative diencephalic modulator for both pain and itch processing. We demonstrated that ZI vesicular glutamate transporter 2 (VGluT2) neurons exhibited increased calcium signal upon hindpaw withdrawal in response to experimental mechanical and thermal stimuli. Behavioral tests further showed that pharmacogenetic activation of this specific type of neurons reduced nocifensive withdrawal responses in both naïve and inflammatory pain mice. Similar neural activity and modulatory role of ZI VGluT2 neurons were also observed upon histaminergic and non-histaminergic acute itch stimuli. Together, our study would expedite our understandings of brain mechanisms underlying somatosensory processing and modulation, and supply a novel therapeutic target for the management of chronic pain and itch disorders.
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Affiliation(s)
- Jiaqi Li
- Department of Neurobiology, Basic Medical Science Academy, Fourth Military Medical University, Xi'an, 710032, China
| | - Shihao Peng
- Department of Neurobiology, Basic Medical Science Academy, Fourth Military Medical University, Xi'an, 710032, China
| | - Yiwen Zhang
- Department of Neurobiology, Basic Medical Science Academy, Fourth Military Medical University, Xi'an, 710032, China
| | - Junye Ge
- Department of Neurobiology, Basic Medical Science Academy, Fourth Military Medical University, Xi'an, 710032, China
| | - Shasha Gao
- Department of Neurobiology, Basic Medical Science Academy, Fourth Military Medical University, Xi'an, 710032, China
| | - Yuanyuan Zhu
- Department of Neurobiology, Basic Medical Science Academy, Fourth Military Medical University, Xi'an, 710032, China
| | - Yang Bai
- Department of Neurosurgery, General Hospital of Northern Theater Command, Shenyang, 110015, China.
| | - Shengxi Wu
- Department of Neurobiology, Basic Medical Science Academy, Fourth Military Medical University, Xi'an, 710032, China.
| | - Jing Huang
- Department of Neurobiology, Basic Medical Science Academy, Fourth Military Medical University, Xi'an, 710032, China.
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Nguyen E, Chiang MC, Nguyen C, Ross SE. Brainstem Modulation of Nociception by Periaqueductal Gray Neurons Expressing the μ-Opioid Receptor in Mice. Anesthesiology 2023; 139:462-475. [PMID: 37364291 PMCID: PMC10870981 DOI: 10.1097/aln.0000000000004668] [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] [Indexed: 06/28/2023]
Abstract
BACKGROUND Pharmacologic manipulations directed at the periaqueductal gray have demonstrated the importance of the μ-opioid receptor in modulating reflexive responses to nociception. The authors hypothesized that a supraspinal pathway centered on neurons in the periaqueductal gray containing the μ-opioid receptor could modulate nociceptive and itch behaviors. METHODS The study used anatomical, optogenetic, and chemogenetic approaches in male and female mice to manipulate μ-opioid receptor neurons in the periaqueductal gray. Behavioral assays including von Frey, Hargreaves, cold plantar, chloroquine-induced itch, hotplate, formalin-induced injury, capsaicin-induced injury, and open field tests were used. In separate experiments, naloxone was administered in a postsurgical model of latent sensitization. RESULTS Activation of μ-opioid receptor neurons in the periaqueductal gray increased jumping (least-squares mean difference of -3.30 s; 95% CI, -6.17 to -0.44; P = 0.023; n = 7 or 8 mice per group), reduced itch responses (least-squares mean difference of 70 scratching bouts; 95% CI, 35 to 105; P < 0.001; n = 8 mice), and elicited modestly antinociceptive effects (least-squares mean difference of -0.7 g on mechanical and -10.24 s on thermal testing; 95% CI, -1.3 to -0.2 and 95% CI, -13.77 to -6.70, and P = 0.005 and P < 0.001, respectively; n = 8 mice). Last, the study uncovered the role of the periaqueductal gray in suppressing hyperalgesia after a postsurgical state of latent sensitization (least-squares mean difference comparing saline and naloxone of -12 jumps; 95% CI, -17 to -7; P < 0.001 for controls; and -2 jumps; 95% CI, -7 to 4; P = 0.706 after optogenetic stimulation; n = 7 to 9 mice per group). CONCLUSIONS μ-Opioid receptor neurons in the periaqueductal gray modulate distinct nocifensive behaviors: their activation reduced responses to mechanical and thermal testing, and attenuated scratching behaviors, but facilitated escape responses. The findings emphasize the role of the periaqueductal gray in the behavioral expression of nociception using reflexive and noxious paradigms. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Eileen Nguyen
- University of Pittsburgh School of Medicine, Department of Anesthesiology, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, USA
- University of California, Los Angeles, Department of Anesthesiology, Los Angeles, CA, USA
| | - Michael C. Chiang
- University of Pittsburgh School of Medicine, Department of Anesthesiology, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, USA
| | - Catherine Nguyen
- University of Pittsburgh School of Medicine, Department of Anesthesiology, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, USA
| | - Sarah E. Ross
- University of Pittsburgh School of Medicine, Department of Anesthesiology, Pittsburgh, PA, USA
- University of Pittsburgh, Department of Neurobiology, Pittsburgh, PA, USA
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23
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Xie L, Wu H, Chen Q, Xu F, Li H, Xu Q, Jiao C, Sun L, Ullah R, Chen X. Divergent modulation of pain and anxiety by GABAergic neurons in the ventrolateral periaqueductal gray and dorsal raphe. Neuropsychopharmacology 2023; 48:1509-1519. [PMID: 36526697 PMCID: PMC10425368 DOI: 10.1038/s41386-022-01520-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/07/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022]
Abstract
The ventrolateral periaqueductal gray (vlPAG) collaborates with the dorsal raphe (DR) in pain regulation and emotional response. However, the roles of vlPAG and DR γ-aminobutyric acid (GABA)-ergic neurons in regulating nociception and anxiety are contradictory and poorly understood. Here, we observed that pharmacogenetic co-activation of vlPAG and DR GABAergic (vlPAG-DRGABA+) neurons enhanced sensitivity to mechanical stimulation and promoted anxiety-like behavior in naïve mice. Simultaneous inhibition of vlPAG-DRGABA+ neurons showed adaptive anti-nociception and anti-anxiety effects on mice with inflammatory pain. Notably, vlPAGGABA+ and DRGABA+ neurons exhibited opposing effects on the sensitivity to mechanical stimulation in both naïve state and inflammatory pain. In contrast to the role of vlPAGGABA+ neurons in pain processing, chemogenetic inhibition and chronic ablation of DRGABA+ neurons remarkably promoted nociception while selectively activating DRGABA+ neurons ameliorated inflammatory pain. Additionally, utilizing optogenetic technology, we observed that the pronociceptive effect arising from DRGABA+ neuronal inhibition was reversed by the systemic administration of morphine. Our results collectively provide new insights into the modulation of pain and anxiety by specific midbrain GABAergic subpopulations, which may provide a basis for cell type-targeted or subregion-targeted therapies for pain management.
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Affiliation(s)
- Linghua Xie
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hui Wu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qing Chen
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Fang Xu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hua Li
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qi Xu
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Cuicui Jiao
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lihong Sun
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Rahim Ullah
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, Zhejiang, China
| | - Xinzhong Chen
- Department of Anesthesia, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
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24
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Bai X, Zhang K, Ou C, Nie B, Zhang J, Huang Y, Zhang Y, Huang J, Ouyang H, Cao M, Huang W. Selective activation of AKAP150/TRPV1 in ventrolateral periaqueductal gray GABAergic neurons facilitates conditioned place aversion in male mice. Commun Biol 2023; 6:742. [PMID: 37460788 PMCID: PMC10352381 DOI: 10.1038/s42003-023-05106-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 07/06/2023] [Indexed: 07/20/2023] Open
Abstract
Aversion refers to feelings of strong dislike or avoidance toward particular stimuli or situations. Aversion can be caused by pain stimuli and has a long-term negative impact on physical and mental health. Aversion can also be caused by drug abuse withdrawal, resulting in people with substance use disorder to relapse. However, the mechanisms underlying aversion remain unclear. The ventrolateral periaqueductal gray (vlPAG) is considered to play a key role in aversive behavior. Our study showed that inhibition of vlPAG GABAergic neurons significantly attenuated the conditioned place aversion (CPA) induced by hindpaw pain pinch or naloxone-precipitated morphine withdrawal. However, activating or inhibiting glutamatergic neurons, or activating GABAergic neurons cannot affect or alter CPA response. AKAP150 protein expression and phosphorylated TRPV1 (p-TRPV1) were significantly upregulated in these two CPA models. In AKAP150flox/flox mice and C57/B6J wild-type mice, cell-type-selective inhibition of AKAP150 in GABAergic neurons in the vlPAG attenuated aversion. However, downregulating AKAP150 in glutamatergic neurons did not attenuate aversion. Knockdown of AKAP150 in GABAergic neurons effectively reversed the p-TRPV1 upregulation in these two CPA models utilized in our study. Collectively, inhibition of the AKAP150/p-TRPV1 pathway in GABAergic neurons in the vlPAG may be considered a potential therapeutic target for the CPA response.
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Affiliation(s)
- Xiaohui Bai
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
- Department of Anesthesiology, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation. Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Kun Zhang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Chaopeng Ou
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Bilin Nie
- Department of Anesthesiology, Guangdong Women and Children Hospital, Guangzhou, China
| | - Jianxing Zhang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yongtian Huang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yingjun Zhang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Jingxiu Huang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Handong Ouyang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.
| | - Minghui Cao
- Department of Anesthesiology, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation. Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
| | - Wan Huang
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.
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25
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Nguyen E, Grajales-Reyes JG, Gereau RW, Ross SE. Cell type-specific dissection of sensory pathways involved in descending modulation. Trends Neurosci 2023; 46:539-550. [PMID: 37164868 PMCID: PMC10836406 DOI: 10.1016/j.tins.2023.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/22/2023] [Accepted: 04/07/2023] [Indexed: 05/12/2023]
Abstract
Decades of research have suggested that stimulation of supraspinal structures, such as the periaqueductal gray (PAG) and rostral ventromedial medulla (RVM), inhibits nocifensive responses to noxious stimulation through a process known as descending modulation. Electrical stimulation and pharmacologic manipulations of the PAG and RVM identified transmitters and neuronal firing patterns that represented distinct cell types. Advances in mouse genetics, in vivo imaging, and circuit tracing methods, in addition to chemogenetic and optogenetic approaches, allowed the characterization of the cells and circuits involved in descending modulation in further detail. Recent work has revealed the importance of PAG and RVM neuronal cell types in the descending modulation of pruriceptive as well as nociceptive behaviors, underscoring their roles in coordinating complex behavioral responses to sensory input. This review summarizes how new technical advances that enable cell type-specific manipulation and recording of neuronal activity have supported, as well as expanded, long-standing views on descending modulation.
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Affiliation(s)
- Eileen Nguyen
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jose G Grajales-Reyes
- Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine in St Louis, St Louis, MO 63110, USA
| | - Robert W Gereau
- Washington University Pain Center and Department of Anesthesiology, Washington University School of Medicine in St Louis, St Louis, MO 63110, USA
| | - Sarah E Ross
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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26
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Zhang Y, Huang X, Xin WJ, He S, Deng J, Ruan X. Somatostatin Neurons from Periaqueductal Gray to Medulla Facilitate Neuropathic Pain in Male Mice. THE JOURNAL OF PAIN 2023; 24:1020-1029. [PMID: 36641028 DOI: 10.1016/j.jpain.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/28/2022] [Accepted: 01/01/2023] [Indexed: 01/13/2023]
Abstract
Projections from the periaqueductal gray (PAG) to the rostral ventromedial medulla (RVM) are known to engage in descending pain modulation, but how the neural substrates of the PAG-RVM projections contribute to neuropathic pain remains largely unknown. In this study, we showed somatostatin-expressing glutamatergic neurons in the lateral/ventrolateral PAG that facilitate mechanical and thermal hypersensitivity in a mouse model of chemotherapy-induced neuropathic pain. We found that these neurons form direct excitatory connections with neurons in the RVM region. Inhibition of this PAG-RVM projection alleviates mechanical and thermal hypersensitivity associated with neuropathy, whereas its activation enhances hypersensitivity in the mice. Thus, our findings revealed that somatostatin neurons within the PAG-RVM axial are crucial for descending pain facilitation and can potentially be exploited as a useful therapeutic target for neuropathic pain. PERSPECTIVE: We report the profound contribution of somatostatin neurons within the PAG-RVM projections to descending pain facilitation underlying neuropathic pain. These results may help to develop central therapeutic strategies for neuropathic pain.
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Affiliation(s)
- Yuehong Zhang
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Xuelin Huang
- Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Wen-Jun Xin
- Zhongshan Medical School and Guangdong Province Key Laboratory of Brain Function and Disease Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Shilang He
- Department of Anesthesia and Pain Medicine, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Jie Deng
- Zhongshan Medical School and Guangdong Province Key Laboratory of Brain Function and Disease Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Xiangcai Ruan
- Department of Anesthesia and Pain Medicine, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China.
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27
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McPherson KB, Bouchet CA, Coutens B, Ingram SL. Persistent inflammation selectively activates opioid-sensitive phasic-firing neurons within the vlPAG. J Neurophysiol 2023; 129:1237-1248. [PMID: 37073984 PMCID: PMC10202481 DOI: 10.1152/jn.00016.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/06/2023] [Accepted: 04/06/2023] [Indexed: 04/20/2023] Open
Abstract
The ventrolateral periaqueductal gray (vlPAG) is a key brain area within the descending pain modulatory pathway and an important target for opioid-induced analgesia. The vlPAG contains heterogeneous neurons with respect to neurotransmitter content, receptor and channel expression, and in vivo response to noxious stimuli. This study characterizes intrinsic membrane properties of vlPAG neurons to identify neuron types that respond to inflammation and determine whether the pain-responsive neurons are inhibited by opioids. Surveying 382 neurons identified four neuron types with distinct intrinsic firing patterns: Phasic (48%), Tonic (33%), Onset (10%), and Random (9%). Mu-opioid receptor (MOR) expression was determined by the ability of a selective MOR agonist (DAMGO) to activate G protein-coupled inwardly rectifying potassium channel (GIRK) currents. Opioid-sensitive neurons were observed within each neuron type. Opioid sensitivity did not correlate with other intrinsic firing features, including low-threshold spiking that has been previously proposed to identify opioid-sensitive GABAergic neurons in the vlPAG of mice. Complete Freund's adjuvant (CFA)-induced acute inflammation (2 h) had no effect on vlPAG neuron firing patterns. However, persistent inflammation (5-7 days) selectively activated Phasic neurons through a significant reduction in their firing threshold. Opioid-sensitive neurons were strongly activated compared with the opioid-insensitive Phasic neurons. Overall, this study provides a framework to further identify neurons activated by persistent inflammation so that they may be targeted for future pain therapies.NEW & NOTEWORTHY Intrinsic firing properties define four distinct vlPAG neuron populations, and a subset of each population expresses MORs coupled to GIRK channels. Persistent, but not acute, inflammation selectively activates opioid-sensitive Phasic vlPAG neurons. Although the vlPAG is known to contribute to the descending inhibition of pain, the activation of a single physiologically defined neuron type in the presence of persistent inflammation represents a mechanism by which the vlPAG participates in descending facilitation of pain.
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Affiliation(s)
- Kylie B McPherson
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon, United States
- The Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Courtney A Bouchet
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon, United States
- The Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Basile Coutens
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon, United States
| | - Susan L Ingram
- Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon, United States
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28
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Buhidma Y, Hobbs C, Malcangio M, Duty S. Periaqueductal grey and spinal cord pathology contribute to pain in Parkinson's disease. NPJ Parkinsons Dis 2023; 9:69. [PMID: 37100804 PMCID: PMC10133233 DOI: 10.1038/s41531-023-00510-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/11/2023] [Indexed: 04/28/2023] Open
Abstract
Pain is a key non-motor feature of Parkinson's disease (PD) that significantly impacts on life quality. The mechanisms underlying chronic pain in PD are poorly understood, hence the lack of effective treatments. Using the 6-hydroxydopamine (6-OHDA) lesioned rat model of PD, we identified reductions in dopaminergic neurons in the periaqueductal grey (PAG) and Met-enkephalin in the dorsal horn of the spinal cord that were validated in human PD tissue samples. Pharmacological activation of D1-like receptors in the PAG, identified as the DRD5+ phenotype located on glutamatergic neurons, alleviated the mechanical hypersensitivity seen in the Parkinsonian model. Downstream activity in serotonergic neurons in the Raphé magnus (RMg) was also reduced in 6-OHDA lesioned rats, as detected by diminished c-FOS positivity. Furthermore, we identified increased pre-aggregate α-synuclein, coupled with elevated activated microglia in the dorsal horn of the spinal cord in those people that experienced PD-related pain in life. Our findings have outlined pathological pathways involved in the manifestation of pain in PD that may present targets for improved analgesia in people with PD.
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Affiliation(s)
- Yazead Buhidma
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, SE1 1UL, UK
| | - Carl Hobbs
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, SE1 1UL, UK
| | - Marzia Malcangio
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, SE1 1UL, UK
| | - Susan Duty
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, SE1 1UL, UK.
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29
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Gu X, Zhang YZ, O'Malley JJ, De Preter CC, Penzo M, Hoon MA. Neurons in the caudal ventrolateral medulla mediate descending pain control. Nat Neurosci 2023; 26:594-605. [PMID: 36894654 PMCID: PMC11114367 DOI: 10.1038/s41593-023-01268-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/27/2023] [Indexed: 03/11/2023]
Abstract
Supraspinal brain regions modify nociceptive signals in response to various stressors including stimuli that elevate pain thresholds. The medulla oblongata has previously been implicated in this type of pain control, but the neurons and molecular circuits involved have remained elusive. Here we identify catecholaminergic neurons in the caudal ventrolateral medulla that are activated by noxious stimuli in mice. Upon activation, these neurons produce bilateral feed-forward inhibition that attenuates nociceptive responses through a pathway involving the locus coeruleus and norepinephrine in the spinal cord. This pathway is sufficient to attenuate injury-induced heat allodynia and is required for counter-stimulus induced analgesia to noxious heat. Our findings define a component of the pain modulatory system that regulates nociceptive responses.
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Affiliation(s)
- Xinglong Gu
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
| | - Yizhen Z Zhang
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
| | - John J O'Malley
- Unit on the Neurobiology of Affective Memory, National Institute of Mental Health, Bethesda, MD, USA
| | - Caitlynn C De Preter
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
| | - Mario Penzo
- Unit on the Neurobiology of Affective Memory, National Institute of Mental Health, Bethesda, MD, USA
| | - Mark A Hoon
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA.
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30
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Torres-Rodriguez JM, Wilson TD, Singh S, Chaudhry S, Adke AP, Becker JJ, Lin JL, Martinez Gonzalez S, Soler-Cedeño O, Carrasquillo Y. The parabrachial to central amygdala circuit is a key mediator of injury-induced pain sensitization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.08.527340. [PMID: 36945586 PMCID: PMC10028796 DOI: 10.1101/2023.02.08.527340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The spino-ponto-amygdaloid pathway is a major ascending circuit relaying nociceptive information from the spinal cord to the brain. Potentiation of excitatory synaptic transmission in the parabrachial nucleus (PbN) to central amygdala (CeA) pathway has been reported in rodent models of persistent pain. At the behavioral level, the PbN→CeA pathway has been proposed to serve as a general alarm system to potential threats that modulates pain-related escape behaviors, threat memory, aversion, and affective-motivational (but not somatosensory) responses to painful stimuli. Increased sensitivity to previously innocuous somatosensory stimulation is a hallmark of chronic pain. Whether the PbN→CeA circuit contributes to heightened peripheral sensitivity following an injury, however, remains unknown. Here, we demonstrate that activation of CeA-projecting PbN neurons contributes to injury-induced behavioral hypersensitivity but not baseline nociception in male and female mice. Using optogenetic assisted circuit mapping, we confirmed a functional excitatory projection from PbN→CeA that is independent of the genetic or firing identity of CeA cells. We then showed that peripheral noxious stimulation increases the expression of the neuronal activity marker c-Fos in CeA-projecting PbN neurons and chemogenetic inactivation of these cells reduces behavioral hypersensitivity in models of neuropathic and inflammatory pain without affecting baseline nociception. Lastly, we show that chemogenetic activation of CeA-projecting PbN neurons is sufficient to induce bilateral hypersensitivity without injury. Together, our results demonstrate that the PbN→CeA pathway is a key modulator of pain-related behaviors that can amplify responses to somatosensory stimulation in pathological states without affecting nociception under normal physiological conditions. Significance Statement Early studies identified the spino-ponto-amygdaloid pathway as a major ascending circuit conveying nociceptive inputs from the spinal cord to the brain. The functional significance of this circuit to injury-induced hypersensitivity, however, remains unknown. Here, we addressed this gap in knowledge using viral-mediated anatomical tracers, ex-vivo electrophysiology and chemogenetic intersectional approaches in rodent models of persistent pain. We found that activation of this pathway contributes to injury-induced hypersensitivity, directly demonstrating a critical function of the PbN→CeA circuit in pain modulation.
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Affiliation(s)
| | - Torri D. Wilson
- National Center for Complementary and Integrative Health, Bethesda, MD, United States
| | - Sudhuman Singh
- National Center for Complementary and Integrative Health, Bethesda, MD, United States
| | - Sarah Chaudhry
- National Center for Complementary and Integrative Health, Bethesda, MD, United States
| | - Anisha P. Adke
- National Center for Complementary and Integrative Health, Bethesda, MD, United States
| | - Jordan J. Becker
- National Center for Complementary and Integrative Health, Bethesda, MD, United States
| | - Jenny L. Lin
- National Center for Complementary and Integrative Health, Bethesda, MD, United States
| | | | - Omar Soler-Cedeño
- National Center for Complementary and Integrative Health, Bethesda, MD, United States
| | - Yarimar Carrasquillo
- National Center for Complementary and Integrative Health, Bethesda, MD, United States
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, United States
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31
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Alam MJ, Chen JDZ. Electrophysiology as a Tool to Decipher the Network Mechanism of Visceral Pain in Functional Gastrointestinal Disorders. Diagnostics (Basel) 2023; 13:627. [PMID: 36832115 PMCID: PMC9955347 DOI: 10.3390/diagnostics13040627] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 01/27/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Abdominal pain, including visceral pain, is prevalent in functional gastrointestinal (GI) disorders (FGIDs), affecting the overall quality of a patient's life. Neural circuits in the brain encode, store, and transfer pain information across brain regions. Ascending pain signals actively shape brain dynamics; in turn, the descending system responds to the pain through neuronal inhibition. Pain processing mechanisms in patients are currently mainly studied with neuroimaging techniques; however, these techniques have a relatively poor temporal resolution. A high temporal resolution method is warranted to decode the dynamics of the pain processing mechanisms. Here, we reviewed crucial brain regions that exhibited pain-modulatory effects in an ascending and descending manner. Moreover, we discussed a uniquely well-suited method, namely extracellular electrophysiology, that captures natural language from the brain with high spatiotemporal resolution. This approach allows parallel recording of large populations of neurons in interconnected brain areas and permits the monitoring of neuronal firing patterns and comparative characterization of the brain oscillations. In addition, we discussed the contribution of these oscillations to pain states. In summary, using innovative, state-of-the-art methods, the large-scale recordings of multiple neurons will guide us to better understanding of pain mechanisms in FGIDs.
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Affiliation(s)
- Md Jahangir Alam
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jiande D. Z. Chen
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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32
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Falconi-Sobrinho LL, Dos Anjos-Garcia T, Hernandes PM, Rodrigues BMDP, Almada RC, Coimbra NC. Unravelling the dorsal periaqueductal grey matter NMDA receptors relevance in the nitric oxide-mediated panic‑like behaviour and defensive antinociception organised by the anterior hypothalamus of male mice. Psychopharmacology (Berl) 2023; 240:319-335. [PMID: 36648509 DOI: 10.1007/s00213-023-06309-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 12/31/2022] [Indexed: 01/18/2023]
Abstract
RATIONALE Previous studies suggested that the dorsal column of the periaqueductal grey matter (dPAG) can be a target of neural pathways from hypothalamic nuclei involved in triggering fear-related defensive responses. In turn, evidence is provided suggesting that microinjection of the nitric oxide (NO) donor SIN-1 into the anterior hypothalamus (AH) of mice evokes panic-like behaviours and fear-induced antinociception. However, it is unknown whether the dPAG of mice mediates these latter defensive responses organised by AH neurons. OBJECTIVES This study was designed to examine the role of dPAG in mediating SIN-1-evoked fear-induced defensive behavioural and antinociceptive responses organised in the AH of mice. METHODS First, neural tract tracing was performed to characterise the AH-dPAG pathways. Then, using neuropharmacological approaches, we evaluated the effects of dPAG pretreatment with either the non-selective synaptic blocker cobalt chloride (CoCl2; 1 mM/0.1 μL) or the competitive N-methyl-D-aspartate (NMDA) receptor antagonist LY235959 (0.1 nmol/0.1 μL) on defensive behaviours and antinociception induced by microinjections of SIN-1 in the AH of male C57BL/6 mice. RESULTS AlexaFluor488-conjugated dextran-labelled axonal fibres from AH neurons were identified in both dorsomedial and dorsolateral PAG columns. Furthermore, we showed that pre-treatment of the dPAG with either CoCl2 or LY235959 inhibited freezing and impaired oriented escape and antinociception induced by infusions of SIN-1 into the AH. CONCLUSIONS These findings suggest that the panic-like freezing and oriented escape defensive behaviours, and fear-induced antinociception elicited by intra-AH microinjections of SIN-1 depend on the activation of dPAG NMDA receptors.
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Affiliation(s)
- Luiz Luciano Falconi-Sobrinho
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (USP), Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
- NAP-USP-Neurobiology of Emotions (NuPNE) Research Centre, Ribeirão Preto Medical School of the University of São Paulo (USP), Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
- Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto, São Paulo, 14220-030, Brazil.
| | - Tayllon Dos Anjos-Garcia
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (USP), Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
- Biomedical Sciences Institute of the Federal University of Alfenas (UNIFAL), Alfenas, Minas Gerais, Brazil
| | - Paloma Molina Hernandes
- Department of Biological Sciences, School of Science, Humanities and Languages, São Paulo State University (UNESP), Assis, São Paulo, Brazil
| | - Bruno Mangili de Paula Rodrigues
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (USP), Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Rafael Carvalho Almada
- Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto, São Paulo, 14220-030, Brazil
- Department of Biological Sciences, School of Science, Humanities and Languages, São Paulo State University (UNESP), Assis, São Paulo, Brazil
| | - Norberto Cysne Coimbra
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (USP), Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
- NAP-USP-Neurobiology of Emotions (NuPNE) Research Centre, Ribeirão Preto Medical School of the University of São Paulo (USP), Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
- Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto, São Paulo, 14220-030, Brazil.
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Kaneko T, Kuwaki T. The opposite roles of orexin neurons in pain and itch neural processing. Peptides 2023; 160:170928. [PMID: 36566840 DOI: 10.1016/j.peptides.2022.170928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 12/17/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022]
Abstract
Pain and itch are antagonistically regulated sensations; pain suppresses itch, and inhibition of pain enhances itch. Understanding the central neural circuit of antagonistic regulation between pain and itch is required to develop new therapeutics better to manage these two feelings in a clinical situation. However, evidence of the neural mechanism underlying the pain-itch interaction in the central nervous system (CNS) is still insufficient. To pave the way for this research area, our laboratory has focused on orexin (ORX) producing neurons in the hypothalamus, which is known as a master switch that induces various defense responses when animals face a stressful environment. This review article summarized the previous evidence and our latest findings to argue the neural regulation between pain and itch and the bidirectional roles of ORX neurons in processing these two sensations. i.e., pain relief and itch exacerbation. Further, we discussed the possible neural circuit mechanism for the opposite controlling of pain and itch by ORX neurons. Focusing on the roles of ORX neurons would provide a new perspective to understand the antagonistic regulation of pain and itch in CNS.
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Affiliation(s)
- Tatsuroh Kaneko
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan.
| | - Tomoyuki Kuwaki
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan
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Islam J, KC E, So KH, Kim S, Kim HK, Park YY, Park YS. Modulation of trigeminal neuropathic pain by optogenetic inhibition of posterior hypothalamus in CCI-ION rat. Sci Rep 2023; 13:489. [PMID: 36627362 PMCID: PMC9831989 DOI: 10.1038/s41598-023-27610-7] [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: 11/04/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Posterior hypothalamus (PH), an important part of the descending pain processing pathway, has been found to be activated in trigeminal autonomic cephalalgias. However, there are very few studies conducted and information regarding its implications in trigeminal neuropathic pain (TNP). Therefore, we aimed to ascertain whether optogenetic inhibition of PH could affect the outcomes of a chronic constriction injury in the infraorbital nerve (CCI-ION) rat model. Animals were divided into the TNP animal, sham, and naive-control groups. CCI-ION surgery was performed to mimic TNP symptoms, and the optogenetic or null virus was injected into the ipsilateral PH. In vivo single-unit extracellular recordings were obtained from both the ipsilateral ventrolateral periaqueductal gray (vlPAG) and contralateral ventral posteromedial (VPM) thalamus in stimulation "OFF" and "ON" conditions. Alterations in behavioral responses during the stimulation-OFF and stimulation-ON states were examined. We observed that optogenetic inhibition of the PH considerably improved behavioral responses in TNP animals. We found increased and decreased firing activity in the vlPAG and VPM thalamus, respectively, during optogenetic inhibition of the PH. Inhibiting PH attenuates trigeminal pain signal transmission by modulating the vlPAG and trigeminal nucleus caudalis, thereby providing evidence of the therapeutic potential of PH in TNP management.
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Affiliation(s)
- Jaisan Islam
- grid.254229.a0000 0000 9611 0917Department of Medical Neuroscience, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Elina KC
- grid.254229.a0000 0000 9611 0917Department of Medical Neuroscience, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Kyoung Ha So
- grid.254229.a0000 0000 9611 0917Institute for Stem Cell and Regenerative Medicine (ISCRM), College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea ,grid.31501.360000 0004 0470 5905Bio-Max/N-Bio Institute, Institute of Bio-Engineering, Seoul National University, Seoul, Republic of Korea
| | - Soochong Kim
- grid.254229.a0000 0000 9611 0917Department of Veterinary Medicine, College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Hyong Kyu Kim
- grid.254229.a0000 0000 9611 0917Department of Medicine and Microbiology, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Yoon Young Park
- grid.411725.40000 0004 1794 4809Department of Neurosurgery, Chungbuk National University Hospital, Cheongju, Republic of Korea
| | - Young Seok Park
- Department of Medical Neuroscience, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea. .,Institute for Stem Cell and Regenerative Medicine (ISCRM), College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea. .,Department of Neurosurgery, Chungbuk National University Hospital, Cheongju, Republic of Korea. .,Department of Neurosurgery, Chungbuk National University Hospital, College of Medicine, Chungbuk National University, 776, 1 Sunhwanro, Seowon-gu, Cheongju-Si, Chungbuk, 28644, Republic of Korea.
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35
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Shin S, You IJ, Jeong M, Bae Y, Wang XY, Cawley ML, Han A, Lim BK. Early adversity promotes binge-like eating habits by remodeling a leptin-responsive lateral hypothalamus-brainstem pathway. Nat Neurosci 2023; 26:79-91. [PMID: 36510113 PMCID: PMC9829538 DOI: 10.1038/s41593-022-01208-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 10/14/2022] [Indexed: 12/14/2022]
Abstract
Early-life trauma (ELT) is a risk factor for binge eating and obesity later in life, yet the neural circuits that underlie this association have not been addressed. Here, we show in mice that downregulation of the leptin receptor (Lepr) in the lateral hypothalamus (LH) and its effect on neural activity is crucial in causing ELT-induced binge-like eating and obesity upon high-fat diet exposure. We also found that the increased activity of Lepr-expressing LH (LHLepr) neurons encodes sustained binge-like eating in ELT mice. Inhibition of LHLepr neurons projecting to the ventrolateral periaqueductal gray normalizes these behavioral features of ELT mice. Furthermore, activation of proenkephalin-expressing ventrolateral periaqueductal gray neurons, which receive inhibitory inputs from LHLepr neurons, rescues ELT-induced maladaptive eating habits. Our results identify a circuit pathway that mediates ELT-induced maladaptive eating and may lead to the identification of novel therapeutic targets for binge eating and obesity.
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Affiliation(s)
- Sora Shin
- Fralin Biomedical Research Institute at VTC, Roanoke, VA, USA.
- FBRI Center for Neurobiology Research, Roanoke, VA, USA.
- Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
| | - In-Jee You
- Fralin Biomedical Research Institute at VTC, Roanoke, VA, USA
- FBRI Center for Neurobiology Research, Roanoke, VA, USA
| | - Minju Jeong
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Yeeun Bae
- Fralin Biomedical Research Institute at VTC, Roanoke, VA, USA
- FBRI Center for Neurobiology Research, Roanoke, VA, USA
- Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Xiao-Yun Wang
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Mikel Leann Cawley
- Fralin Biomedical Research Institute at VTC, Roanoke, VA, USA
- FBRI Center for Neurobiology Research, Roanoke, VA, USA
| | - Abraham Han
- Fralin Biomedical Research Institute at VTC, Roanoke, VA, USA
- FBRI Center for Neurobiology Research, Roanoke, VA, USA
- Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Byung Kook Lim
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
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Gan Z, Gangadharan V, Liu S, Körber C, Tan LL, Li H, Oswald MJ, Kang J, Martin-Cortecero J, Männich D, Groh A, Kuner T, Wieland S, Kuner R. Layer-specific pain relief pathways originating from primary motor cortex. Science 2022; 378:1336-1343. [PMID: 36548429 DOI: 10.1126/science.add4391] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The primary motor cortex (M1) is involved in the control of voluntary movements and is extensively mapped in this capacity. Although the M1 is implicated in modulation of pain, the underlying circuitry and causal underpinnings remain elusive. We unexpectedly unraveled a connection from the M1 to the nucleus accumbens reward circuitry through a M1 layer 6-mediodorsal thalamus pathway, which specifically suppresses negative emotional valence and associated coping behaviors in neuropathic pain. By contrast, layer 5 M1 neurons connect with specific cell populations in zona incerta and periaqueductal gray to suppress sensory hypersensitivity without altering pain affect. Thus, the M1 employs distinct, layer-specific pathways to attune sensory and aversive-emotional components of neuropathic pain, which can be exploited for purposes of pain relief.
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Affiliation(s)
- Zheng Gan
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Vijayan Gangadharan
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Sheng Liu
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Christoph Körber
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Linette Liqi Tan
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Han Li
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Manfred Josef Oswald
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Juhyun Kang
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Jesus Martin-Cortecero
- Institute for Physiology and Pathophysiology, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Deepitha Männich
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Alexander Groh
- Institute for Physiology and Pathophysiology, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Thomas Kuner
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Sebastian Wieland
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany.,Department of General Internal Medicine and Psychosomatics, Medical Faculty Heidelberg and University Clinic Heidelberg, Heidelberg, Germany
| | - Rohini Kuner
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
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Manning CE, Fritz M, Kauer JA. Function of Excitatory Periaqueductal Gray Synapses in the Ventral Tegmental Area following Inflammatory Injury. eNeuro 2022; 9:ENEURO.0324-22.2022. [PMID: 36635253 PMCID: PMC9797208 DOI: 10.1523/eneuro.0324-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 10/26/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Manipulating the activity of ventral tegmental area (VTA) dopamine (DA) neurons can drive nocifensive reflexes, and their firing rates are reduced following noxious stimuli. However, the pain-relevant inputs to the VTA remain incompletely understood. In this study, we used male and female mice in combination with identified dopamine and GABA neurons in the VTA that receive excitatory inputs from the periaqueductal gray (PAG), a nexus of ascending pain information. We tested whether PAG-VTA synapses undergo functional plasticity in response to a pain model using optical stimulation in conjunction with slice electrophysiology. We found that acute carrageenan inflammation does not significantly affect the strength of excitatory PAG synapses onto VTA DA neurons. However, at the PAG synapses on VTA GABA neurons, the subunit composition of NMDA receptors is altered; the complement of NR2D subunits at synaptic sites appears to be lost. Thus, our data support a model in which injury initially alters synapses on VTA GABA neurons. Over time, these alterations may increase tonic inhibition of VTA DA neurons leading to their reduced firing.
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Affiliation(s)
- Claire Elena Manning
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California 94305-5101
| | - Michael Fritz
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California 94305-5101
| | - Julie Ann Kauer
- Nancy Pritzker Laboratory, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California 94305-5101
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Anderson AR, Monroe TB, Dietrich MS, Bruehl SP, Iversen WL, Cowan RL, Failla MD. Increased pain unpleasantness and pain-related fMRI activation in the periaqueductal gray in Alzheimer's disease. FRONTIERS IN PAIN RESEARCH 2022; 3:914473. [PMID: 36387417 PMCID: PMC9650512 DOI: 10.3389/fpain.2022.914473] [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: 04/06/2022] [Accepted: 10/07/2022] [Indexed: 01/25/2023] Open
Abstract
Background Pain continues to be underrecognized and undertreated in people with Alzheimer's disease (AD). The periaqueductal gray (PAG) is essential to pain processing and modulation yet is damaged by AD. While evidence exists of altered neural processing of pain in AD, there has not been a focused investigation of the PAG during pain in people with AD. Purpose To investigate the role of the PAG in sensory and affective pain processing for people living with AD. Methods Participants from a larger study completed pain psychophysics assessments and then a perceptually-matched heat pain task (warmth, mild, and moderate pain) during a functional MRI scan. In this cross-sectional study, we examined blood oxygenation level-dependent (BOLD) responses in the PAG and other pain-related regions in participants with AD (n = 18) and cognitively intact older adults (age- and sex-matched, n = 18). Associations of BOLD percent signal change and psychophysics were also examined. Results There were significant main effects of AD status on the temperature needed to reach each perception of warmth or pain, where people with AD reached higher temperatures. Furthermore, participants with AD rated mild and moderate pain as more unpleasant than controls. PAG BOLD activation was greater in AD relative to controls during warmth and mild pain percepts. No significant differences were found for moderate pain or in other regions of interest. Greater PAG activation during mild pain was associated with higher affective/unpleasantness ratings of mild pain in participants with AD but not in controls. Conclusion Results suggest a role for the PAG in altered pain responses in people with AD. The PAG is the primary source of endogenous opioid pain inhibition in the neuroaxis, thus, altered PAG function in AD suggests possible changes in descending pain inhibitory circuits. People with AD may have a greater risk of suffering from pain compared to cognitively intact older adults.
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Affiliation(s)
- Alison R. Anderson
- Center for Complex Care, Self-Management and Healthy Aging, The Ohio State University, College of Nursing, Columbus, OH, United States
- School of Nursing, Vanderbilt University, Nashville, TN, United States
| | - Todd B. Monroe
- Center for Complex Care, Self-Management and Healthy Aging, The Ohio State University, College of Nursing, Columbus, OH, United States
- School of Nursing, Vanderbilt University, Nashville, TN, United States
- Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Mary S. Dietrich
- School of Nursing, Vanderbilt University, Nashville, TN, United States
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Stephen P. Bruehl
- Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - W. Larkin Iversen
- Center for Complex Care, Self-Management and Healthy Aging, The Ohio State University, College of Nursing, Columbus, OH, United States
| | - Ronald L. Cowan
- Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States
- Departments of Psychiatry and Anatomy and Neurobiology, University of Tennessee Health Science Center, College of Medicine, Memphis, TN, United States
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Michelle D. Failla
- Center for Complex Care, Self-Management and Healthy Aging, The Ohio State University, College of Nursing, Columbus, OH, United States
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
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Winters BL, Lau BK, Vaughan CW. Cannabinoids and Opioids Differentially Target Extrinsic and Intrinsic GABAergic Inputs onto the Periaqueductal Grey Descending Pathway. J Neurosci 2022; 42:7744-7756. [PMID: 36414010 PMCID: PMC9581564 DOI: 10.1523/jneurosci.0997-22.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 07/01/2022] [Accepted: 07/12/2022] [Indexed: 12/14/2022] Open
Abstract
The midbrain periaqueductal gray (PAG) plays a central role in pain modulation via descending pathways. Opioids and cannabinoids are thought to activate these descending pathways by relieving intrinsic GABAergic inhibition of PAG neurons which project to the rostroventromedial medulla (RVM), a process known as disinhibition. However, the PAG also receives descending extrinsic GABAergic inputs from the central nucleus of the amygdala (CeA) which are thought to inhibit PAG GABAergic interneurons. It remains unclear how opioids and cannabinoids act at these different synapses to control descending analgesic pathways. We used optogenetics, tract tracing and electrophysiology to identify the circuitry underlying opioid and cannabinoid actions within the PAG of male and female rats. It was observed that both RVM-projection and nonprojection PAG neurons received intrinsic-PAG and extrinsic-CeA synaptic inputs, which were predominantly GABAergic. Opioids acted via presynaptic µ-receptors to suppress both intrinsic and extrinsic GABAergic inputs onto all PAG neurons, although this inhibition was greater in RVM-projection neurons. By contrast, cannabinoids acted via presynaptic CB1 receptors to exclusively suppress the direct descending GABAergic input from the CeA onto RVM-projection PAG neurons. These findings indicate the CeA controls PAG output neurons which project to the RVM via parallel direct and indirect GABAergic pathways. While µ-opioids indiscriminately inhibit GABAergic inputs onto all PAG neurons, cannabinoids selectively inhibit a direct extrinsic GABAergic input from the amygdala onto PAG projection neurons. These differential actions of opioids and cannabinoids provide a flexible system to gate the descending control of analgesia from the PAG.SIGNIFICANCE STATEMENT The disinhibition hypothesis of analgesia states that opioids activate the midbrain periaqueductal gray (PAG) descending pathway by relieving the tonic inhibition of projection neurons from GABAergic interneurons. However, the PAG also receives extrinsic GABAergic inputs and is the locus of action of cannabinoid analgesics. Here, we show the relative sensitivity of GABAergic synapses to opioids and cannabinoids within the PAG depends on both the origin of presynaptic inputs and their postsynaptic targets. While opioids indiscriminately inhibit all GABAergic inputs onto all PAG neurons, cannabinoids selectively inhibit a direct extrinsic GABAergic input from the amygdala onto PAG descending projection neurons. These differential actions of opioids and cannabinoids provide a flexible system to gate PAG descending outputs.
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Affiliation(s)
- Bryony L Winters
- Pain Management Research Institute, Kolling Institute, Faculty of Medicine and Health, The University of Sydney, Royal North Shore Hospital, New South Wales 2065, Australia
| | - Benjamin K Lau
- Pain Management Research Institute, Kolling Institute, Faculty of Medicine and Health, The University of Sydney, Royal North Shore Hospital, New South Wales 2065, Australia
| | - Christopher W Vaughan
- Pain Management Research Institute, Kolling Institute, Faculty of Medicine and Health, The University of Sydney, Royal North Shore Hospital, New South Wales 2065, Australia
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40
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Neurocircuit of chronic pain and pain-induced negative emotions and regulatory mechanisms of electroacupuncture. WORLD JOURNAL OF ACUPUNCTURE-MOXIBUSTION 2022. [DOI: 10.1016/j.wjam.2022.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Roberts CJ, Hopp FA, Hogan QH, Dean C. Anandamide in the dorsal periaqueductal gray inhibits sensory input without a correlation to sympathoexcitation. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2022; 12:100104. [PMID: 36531614 PMCID: PMC9755024 DOI: 10.1016/j.ynpai.2022.100104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/09/2022] [Accepted: 09/15/2022] [Indexed: 01/11/2023]
Abstract
There is growing literature supporting cannabinoids as a potential therapeutic for pain conditions. The development of chronic pain has been associated with reduced concentrations of the endogenous cannabinoid anandamide (AEA) in the midbrain dorsal periaqueductal gray (dPAG), and microinjections of synthetic cannabinoids into the dPAG are antinociceptive. Therefore, the goal of this study was to examine the role of the dPAG in cannabinoid-mediated sensory inhibition. Given that cannabinoids in the dPAG also elicit sympathoexcitation, a secondary goal was to assess coordination between sympathetic and antinociceptive responses. AEA was microinjected into the dPAG while recording single unit activity of wide dynamic range (WDR) dorsal horn neurons (DHNs) evoked by high intensity mechanical stimulation of the hindpaw, concurrently with renal sympathetic nerve activity (RSNA), in anesthetized male rats. AEA microinjected into the dPAG decreased evoked DHN activity (n = 24 units), for half of which AEA also elicited sympathoexcitation. AEA actions were mediated by cannabinoid 1 receptors as confirmed by local pretreatment with the cannabinoid receptor antagonist AM281. dPAG microinjection of the synaptic excitant DL-homocysteic acid (DLH) also decreased evoked DHN activity (n = 27 units), but in all cases this was accompanied by sympathoexcitation. Thus, sensory inhibition elicited from the dPAG is not exclusively linked with sympathoexcitation, suggesting discrete neuronal circuits. The rostrocaudal location of sites may affect evoked responses as AEA produced sensory inhibition without sympathetic effects at 86 % of caudal compared to 25 % of rostral sites, supporting anatomically distinct neurocircuits. These data indicate that spatially selective manipulation of cannabinoid signaling could provide analgesia without potentially harmful autonomic activation.
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Key Words
- AEA, N-arachidonylethanolamine, anandamide
- Antinociception
- CB1R, cannabinoid type one receptor
- CV, cardiovascular
- Cannabinoid
- DHN, dorsal horn neuron
- DLH, DL-homocysteic acid
- Dorsal horn
- FAAH, fatty acid amide hydrolase
- GPCR, G protein-coupled receptor
- IML, intermediolateral cell column
- MAP, mean arterial pressure
- NTS, nucleus tractus solitarius
- PAG, periaqueductal gray
- PPAR, peroxisome proliferator activated receptor
- RSNA, renal sympathetic nerve activity
- RVLM, rostral ventrolateral medulla
- RVMM, rostral ventromedial medulla
- Rat
- SIA, stress-induced analgesia
- SNS, sympathetic nervous system
- Sympathetic nervous system
- TRPV1, transient receptor potential vanilloid type 1
- WDR, wide dynamic range
- dPAG, dorsal periaqueductal gray
- vPAG, ventral periaqueductal gray
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Affiliation(s)
- Christopher J. Roberts
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA
| | - Francis A. Hopp
- Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA
| | - Quinn H. Hogan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA
| | - Caron Dean
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA,Department of Anesthesiology, Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA,Corresponding author at: Department of Anesthesiology, Research Service 151, Zablocki VA Medical Center, Milwaukee, WI 53295, USA.
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42
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Follansbee T, Domocos D, Nguyen E, Nguyen A, Bountouvas A, Velasquez L, Iodi Carstens M, Takanami K, Ross SE, Carstens E. Inhibition of itch by neurokinin 1 receptor (Tacr1) -expressing ON cells in the rostral ventromedial medulla in mice. eLife 2022; 11:69626. [PMID: 35972457 PMCID: PMC9381038 DOI: 10.7554/elife.69626] [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: 04/21/2021] [Accepted: 08/04/2022] [Indexed: 12/03/2022] Open
Abstract
The rostral ventromedial medulla (RVM) is important in descending modulation of spinal nociceptive transmission, but it is unclear if the RVM also modulates spinal pruriceptive transmission. RVM ON cells are activated by noxious algesic and pruritic stimuli and are pronociceptive. Many RVM-spinal projection neurons express the neurokinin-1 receptor (Tacr1), and ON-cells are excited by local administration of substance P (SP). We hypothesized that Tacr1-expressing RVM ON cells exert an inhibitory effect on itch opposite to their pronociceptive action. Intramedullary microinjection of SP significantly potentiated RVM ON cells and reduced pruritogen-evoked scratching while producing mild mechanical sensitization. Chemogenetic activation of RVM Tacr1-expressing RVM neurons also reduced acute pruritogen-evoked scratching. Optotagging experiments confirmed RVM Tacr1-expressing neurons to be ON cells. We conclude that Tacr1-expressing ON cells in RVM play a significant role in the modulation of pruriceptive transmission.
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Affiliation(s)
- Taylor Follansbee
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States.,Department of Neuroscience, Johns Hopkins University, Baltimore, United States
| | - Dan Domocos
- Department of Anatomy, Animal Physiology and Biophysics, University of Bucharest, Bucharest, Romania
| | - Eileen Nguyen
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh, United States
| | - Amanda Nguyen
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Aristea Bountouvas
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Lauren Velasquez
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Mirela Iodi Carstens
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
| | - Keiko Takanami
- Department of Environmental Life Science, National Nara Women University, Nara, Japan
| | - Sarah E Ross
- Pittsburgh Center for Pain Research and Department of Neurobiology, University of Pittsburgh, Pittsburgh, United States
| | - Earl Carstens
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, United States
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43
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McPherson KB, Ingram SL. Cellular and circuit diversity determines the impact of endogenous opioids in the descending pain modulatory pathway. Front Syst Neurosci 2022; 16:963812. [PMID: 36045708 PMCID: PMC9421147 DOI: 10.3389/fnsys.2022.963812] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/15/2022] [Indexed: 01/31/2023] Open
Abstract
The descending pain modulatory pathway exerts important bidirectional control of nociceptive inputs to dampen and/or facilitate the perception of pain. The ventrolateral periaqueductal gray (vlPAG) integrates inputs from many regions associated with the processing of nociceptive, cognitive, and affective components of pain perception, and is a key brain area for opioid action. Opioid receptors are expressed on a subset of vlPAG neurons, as well as on both GABAergic and glutamatergic presynaptic terminals that impinge on vlPAG neurons. Microinjection of opioids into the vlPAG produces analgesia and microinjection of the opioid receptor antagonist naloxone blocks stimulation-mediated analgesia, highlighting the role of endogenous opioid release within this region in the modulation of nociception. Endogenous opioid effects within the vlPAG are complex and likely dependent on specific neuronal circuits activated by acute and chronic pain stimuli. This review is focused on the cellular heterogeneity within vlPAG circuits and highlights gaps in our understanding of endogenous opioid regulation of the descending pain modulatory circuits.
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Affiliation(s)
- Kylie B. McPherson
- Division of Neuroscience and Clinical Pharmacology, Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy,Department of Neurological Surgery, Oregon Health & Science University, Portland, OR, United States
| | - Susan L. Ingram
- Department of Neurological Surgery, Oregon Health & Science University, Portland, OR, United States,*Correspondence: Susan L. Ingram
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44
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Nguyen E, Smith KM, Cramer N, Holland RA, Bleimeister IH, Flores-Felix K, Silberberg H, Keller A, Le Pichon CE, Ross SE. Medullary kappa-opioid receptor neurons inhibit pain and itch through a descending circuit. Brain 2022; 145:2586-2601. [PMID: 35598161 PMCID: PMC9612802 DOI: 10.1093/brain/awac189] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/01/2022] [Accepted: 04/27/2022] [Indexed: 11/13/2022] Open
Abstract
In perilous and stressful situations, the ability to suppress pain can be critical for survival. The rostral ventromedial medulla contains neurons that robustly inhibit nocioception at the level of the spinal cord through a top-down modulatory pathway. Although much is known about the role of the rostral ventromedial medulla in the inhibition of pain, the precise ability to directly manipulate pain-inhibitory neurons in the rostral ventromedial medulla has never been achieved. We now expose a cellular circuit that inhibits nocioception and itch in mice. Through a combination of molecular, tracing and behavioural approaches, we found that rostral ventromedial medulla neurons containing the kappa-opioid receptor inhibit itch and nocioception. With chemogenetic inhibition, we uncovered that these neurons are required for stress-induced analgesia. Using intersectional chemogenetic and pharmacological approaches, we determined that rostral ventromedial medulla kappa-opioid receptor neurons inhibit nocioception and itch through a descending circuit. Lastly, we identified a dynorphinergic pathway arising from the periaqueductal grey that modulates nociception within the rostral ventromedial medulla. These discoveries highlight a distinct population of rostral ventromedial medulla neurons capable of broadly and robustly inhibiting itch and nocioception.
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Affiliation(s)
- Eileen Nguyen
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Kelly M Smith
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Nathan Cramer
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | - Ruby A Holland
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Isabel H Bleimeister
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Krystal Flores-Felix
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | - Hanna Silberberg
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Asaf Keller
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | - Claire E Le Pichon
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sarah E Ross
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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45
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Wang W, Zhang X, Bai X, Zhang Y, Yuan Z, Tang H, Li Z, Hu Z, Zhang Y, Yu X, Sui B, Wang Y. Gamma-aminobutyric acid and glutamate/glutamine levels in the dentate nucleus and periaqueductal gray with episodic and chronic migraine: a proton magnetic resonance spectroscopy study. J Headache Pain 2022; 23:83. [PMID: 35840907 PMCID: PMC9287958 DOI: 10.1186/s10194-022-01452-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/04/2022] [Indexed: 11/19/2022] Open
Abstract
Background The pathogenesis of migraine chronification remains unclear. Functional and structural magnetic resonance imaging studies have shown impaired functional and structural alterations in the brains of patients with chronic migraine. The cerebellum and periaqueductal gray (PAG) play pivotal roles in the neural circuits of pain conduction and analgesia in migraine. However, few neurotransmitter metabolism studies of these migraine-associated regions have been performed. To explore the pathogenesis of migraine chronification, we measured gamma-aminobutyric acid (GABA) and glutamate/glutamine (Glx) levels in the dentate nucleus (DN) and PAG of patients with episodic and chronic migraine and healthy subjects. Methods Using the MEGA-PRESS sequence and a 3-Tesla magnetic resonance scanner (Signa Premier; GE Healthcare, Chicago, IL, USA), we obtained DN and PAG metabolite concentrations from patients with episodic migraine (n = 25), those with chronic migraine (n = 24), and age-matched and sex-matched healthy subjects (n = 16). Patients with chronic migraine were further divided into those with (n = 12) and without (n = 12) medication overuse headache. All scans were performed at the Beijing Tiantan Hospital, Capital Medical University. Results We found that patients with chronic migraine had significantly lower levels of GABA/water (p = 0.011) and GABA/creatine (Cr) (p = 0.026) in the DN and higher levels of Glx/water (p = 0.049) in the PAG than healthy controls. In all patients with migraine, higher GABA levels in the PAG were significantly associated with poorer sleep quality (GABA/water: r = 0.515, p = 0.017, n = 21; GABA/Cr: r = 0.522, p = 0.015, n = 21). Additionally, a lower Glx/Cr ratio in the DN may be associated with more severe migraine disability (r = -0.425, p = 0.055, n = 20), and lower GABA/water (r = -0.424, p = 0.062, n = 20) and Glx/Water (r = -0.452, p = 0.045, n = 20) may be associated with poorer sleep quality. Conclusions Neurochemical levels in the DN and PAG may provide evidence of the pathological mechanisms of migraine chronification. Correlations between migraine characteristics and neurochemical levels revealed the pathological mechanisms of the relevant characteristics. Supplementary Information The online version contains supplementary material available at 10.1186/s10194-022-01452-6.
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Affiliation(s)
- Wei Wang
- Headache Center, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China
| | - Xueyan Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, No.1, Jianshe East Road, Zhengzhou, Henan Province, 450000, China
| | - Xiaoyan Bai
- Tiantan Neuroimaging Center of Excellence, China National Clinical Research Center for Neurological Diseases, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China.,Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China
| | - Yingkui Zhang
- Tiantan Neuroimaging Center of Excellence, China National Clinical Research Center for Neurological Diseases, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China
| | - Ziyu Yuan
- Headache Center, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China
| | - Hefei Tang
- Headache Center, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China
| | - Zhiye Li
- Tiantan Neuroimaging Center of Excellence, China National Clinical Research Center for Neurological Diseases, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China.,Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China
| | - Zhangxuan Hu
- GE Healthcare, No.1 Tongji Nan Road, Beijing Economic Technological Development Area, Beijing, 100070, China
| | - Yaqing Zhang
- Headache Center, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China
| | - Xueying Yu
- Headache Center, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China
| | - Binbin Sui
- Tiantan Neuroimaging Center of Excellence, China National Clinical Research Center for Neurological Diseases, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China.
| | - Yonggang Wang
- Headache Center, Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, No.119 South Fourth Ring West Road, Fengtai District, Beijing, 100070, China.
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46
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La-Vu MQ, Sethi E, Maesta-Pereira S, Schuette PJ, Tobias BC, Reis FMCV, Wang W, Torossian A, Bishop A, Leonard SJ, Lin L, Cahill CM, Adhikari A. Sparse genetically defined neurons refine the canonical role of periaqueductal gray columnar organization. eLife 2022; 11:77115. [PMID: 35674316 PMCID: PMC9224993 DOI: 10.7554/elife.77115] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 05/25/2022] [Indexed: 11/13/2022] Open
Abstract
During threat exposure, survival depends on defensive reactions. Prior works linked large glutamatergic populations in the midbrain periaqueductal gray (PAG) to defensive freezing and flight, and established that the overarching functional organization axis of the PAG is along anatomically-defined columns. Accordingly, broad activation of the dorsolateral column induces flight, while activation of the lateral or ventrolateral (l and vl) columns induces freezing. However, the PAG contains diverse cell types that vary in neurochemistry. How these cell types contribute to defense remains unknown, indicating that targeting sparse, genetically-defined populations may reveal how the PAG generates diverse behaviors. Though prior works showed that broad excitation of the lPAG or vlPAG causes freezing, we found in mice that activation of lateral and ventrolateral PAG (l/vlPAG) cholecystokinin-expressing (CCK) cells selectively caused flight to safer regions within an environment. Furthermore, inhibition of l/vlPAG-CCK cells reduced predator avoidance without altering other defensive behaviors like freezing. Lastly, l/vlPAG-CCK activity decreased when approaching threat and increased during movement to safer locations. These results suggest CCK cells drive threat avoidance states, which are epochs during which mice increase distance from threat and perform evasive escape. Conversely, l/vlPAG pan-neuronal activation promoted freezing, and these cells were activated near threat. Thus, CCK l/vlPAG cells have opposing function and neural activation motifs compared to the broader local ensemble defined solely by columnar boundaries. In addition to the anatomical columnar architecture of the PAG, the molecular identity of PAG cells may confer an additional axis of functional organization, revealing unexplored functional heterogeneity.
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Affiliation(s)
- Mimi Q La-Vu
- Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, United States.,Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Ekayana Sethi
- Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Sandra Maesta-Pereira
- Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Peter J Schuette
- Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, United States.,Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Brooke C Tobias
- Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Fernando M C V Reis
- Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Weisheng Wang
- Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Anita Torossian
- Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, United States.,Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Amy Bishop
- Hatos Center for Neuropharmacology, University of California, Los Angeles, Los Angeles, United States
| | - Saskia J Leonard
- Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Lilly Lin
- Department of Psychology, University of California, Los Angeles, Los Angeles, United States
| | - Catherine M Cahill
- Hatos Center for Neuropharmacology, University of California, Los Angeles, Los Angeles, United States.,Department of Psychiatry and Biobehavioral Sciences, Los Angeles, United States.,Semel Institute for Neuroscience and Human Behavior, Los Angeles, United States
| | - Avishek Adhikari
- Department of Psychology, University of California, Los Angeles, Los Angeles, United States
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47
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Wang L, Fu LL, Deng ZR, Zhang J, Zu MD, Wu JC, Wang Y. Overexpression of BDNF in the ventrolateral periaqueductal gray regulates the behavior of epilepsy-migraine comorbid rats. Brain Behav 2022; 12:e2594. [PMID: 35557046 PMCID: PMC9226826 DOI: 10.1002/brb3.2594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/15/2022] [Accepted: 04/04/2022] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE To investigate the effects of brain-derived neurotrophic factor (BDNF) overexpression in the ventrolateral periaqueductal gray (vlPAG) on behavioral changes in epilepsy-migraine comorbid rats. METHOD We used an adeno-associated virus (AAV)-mediated vector to supplement BDNF in the vlPAG area prior to the establishment of a pilocarpine-nitroglycerin (Pilo-NTG) combination-induced comorbid model of epilepsy and migraine. Seizure- and migraine-related behaviors were analyzed. Cell loss and apoptosis in vlPAG were detected through hematoxylin-eosin (HE) and TUNEL staining. Immunofluorescence staining analyses were employed to detect expressions of BDNF and its receptor, tyrosine kinase B (TrkB), in vlPAG. Immunohistochemical staining was conducted to detect expressions of c-Fos and calcitonin gene-related peptide (CGRP) in the trigeminal nucleus caudalis (TNC) and trigeminal ganglion (TG). RESULTS Comparing to control group, AAV-BDNF injected comorbid group showed lower pain sensitivity, scratching head, and spontaneous seizures accompanied by the downregulation of c-Fos labeling neurons and CGRP immunoreactivity in the TNC and TG. However, these changes were still significantly higher in the comorbid group than those in both epilepsy and migraine groups under the same intervention. CONCLUSION These data demonstrated that supplying BDNF to vlPAG may protect structural and functional abnormalities in vlPAG and provide an antiepileptic and analgesic therapy.
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Affiliation(s)
- Long Wang
- Department of Neurology, The Second People's Hospital of Hefei, Hefei, China.,Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Lu-Lan Fu
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zi-Ru Deng
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Juan Zhang
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Mei-Dan Zu
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jun-Cang Wu
- Department of Neurology, The Second People's Hospital of Hefei, Hefei, China
| | - Yu Wang
- Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
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48
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Khalouzadeh F, Azizi H, Semnanian S. Adolescent nicotine exposure increases nociceptive behaviors in rat model of formalin test: Involvement of ventrolateral periaqueductal gray neurons. Life Sci 2022; 299:120551. [PMID: 35421453 DOI: 10.1016/j.lfs.2022.120551] [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: 02/18/2022] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 11/18/2022]
Abstract
Among the major life-threatening factors, smoking tobacco is the leading cause of death worldwide. Adolescence is a sensitive stage of brain development, and smoking at this age is thought to be associated with neural and behavioral alterations. Currently the association between adolescent tobacco use and pain perception remained to be addressed. It is also important to consider that the periaqueductal gray (PAG) is a major component of the descending pain inhibitory system. The present study was performed to reveal the possible effects of adolescent nicotine consumption on pain-related behaviors and also the antinociceptive effect of a single dose of morphine administration besides the ventrolateral PAG (vlPAG) firing assessment in adulthood during formalin test. Adolescent male Wistar rats were administered with either a nicotine or saline injection (s.c.), and after 30 days of washout period, formalin test was performed. The vlPAG neuronal responses to formalin injection were recorded via in vivo extracellular single-unit recording. The results demonstrated that adolescent nicotine exposure enhances behavioral responses to pain. It also reduced morphine-induced antinociceptive behavior in the formalin test during adulthood. Moreover, adolescent nicotine exposure attenuates the extent of vlPAG inhibitory response to formalin. Our data provided a further conclusion that adolescent nicotine exposure may alter the pain modulatory systems and their subsequent response to painful stimuli.
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Affiliation(s)
- Fatemeh Khalouzadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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49
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Hiroki T, Suto T, Ohta J, Saito S, Obata H. Spinal γ-Aminobutyric Acid Interneuron Plasticity Is Involved in the Reduced Analgesic Effects of Morphine on Neuropathic Pain. THE JOURNAL OF PAIN 2022; 23:547-557. [PMID: 34678470 DOI: 10.1016/j.jpain.2021.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/16/2021] [Accepted: 10/05/2021] [Indexed: 12/25/2022]
Abstract
Systemic administration of morphine increases serotonin (5-HT) in the spinal dorsal horn (SDH), which attenuates the analgesic effects of morphine on neuropathic pain through spinal 5-HT3 receptors. We hypothesized that dysfunction of the descending serotonergic system, including the periaqueductal gray (PAG), contributes to attenuate the efficacy of morphine on neuropathic pain through spinal 5-HT3 receptors and GABA neurons. Morphine (100 ng) injected into the PAG produced analgesic effects in normal rats, but not in spinal nerve ligation (SNL) rats. In vivo microdialysis showed that PAG morphine increased the SDH 5-HT concentration in both groups. Intrathecal injection of the 5-HT3 receptor antagonist ondansetron and the GABAA receptor antagonist bicuculline attenuated the analgesic effects of PAG morphine in normal rats, but increased the effects in SNL rats. The increased analgesic effect of PAG morphine induced by bicuculline was reversed by pretreatment with the tropomyosin receptor kinase B (TrkB) antagonist K252a. Activation of spinal 5-HT3 receptors by 2-methyl-5-HT increased the GABA concentration in both groups. Morphine activates GABAergic interneurons in the SDH by activating descending serotonergic neurons. Functional changes in GABAA receptors from inhibitory to facilitatory through the activation of TrkB receptors may contribute to the attenuated efficacy of morphine against neuropathic pain. PERSPECTIVE: Although morphine provides strong analgesia against acute pain, it has limited efficacy against neuropathic pain. This article demonstrates that functional changes in GABAA receptors in the spinal dorsal horn after nerve injury might strongly contribute to the attenuation of opioid-induced analgesia for neuropathic pain.
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Affiliation(s)
- Tadanao Hiroki
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan.
| | - Takashi Suto
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Jo Ohta
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shigeru Saito
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hideaki Obata
- Department of Anesthesiology, Saitama Medical Center, Saitama Medical University, Kawagoe, Japan
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50
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Hu Z, Mu Y, Huang L, Hu Y, Chen Z, Yang Y, Huang X, Fu Y, Xi Y, Lin S, Tao Q, Xu F, So KF, Ren C. A visual circuit related to the periaqueductal gray area for the antinociceptive effects of bright light treatment. Neuron 2022; 110:1712-1727.e7. [PMID: 35263618 DOI: 10.1016/j.neuron.2022.02.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/23/2022] [Accepted: 02/14/2022] [Indexed: 12/21/2022]
Abstract
Light is a powerful modulator of non-visual functions. Although accumulating evidence suggests an antinociceptive effect of bright light treatment, the precise circuits that mediate the effects of light on nocifensive behaviors remain unclear. Here, we show that bright light treatment suppresses mouse nocifensive behaviors through a visual circuit related to the lateral and ventral lateral parts of the periaqueductal gray area (l/vlPAG). Specifically, a subset of retinal ganglion cells (RGCs) innervates GABAergic neurons in the ventral lateral geniculate nucleus and intergeniculate leaflet (vLGN/IGL), which in turn inhibit GABAergic neurons in the l/vlPAG. The activation of vLGN/IGL-projecting RGCs, activation of l/vlPAG-projecting vLGN/IGL neurons, or inhibition of postsynaptic l/vlPAG neurons is sufficient to suppress nocifensive behaviors. Importantly, we demonstrate that the antinociceptive effects of bright light treatment are dependent on the activation of the retina-vLGN/IGL-l/vlPAG pathway. Together, our results delineate an l/vlPAG-related visual circuit underlying the antinociceptive effects of bright light treatment.
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Affiliation(s)
- Zhengfang Hu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou 510632, China
| | - Yiman Mu
- Psychology Department, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Lu Huang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou 510632, China
| | - Yuqing Hu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou 510632, China
| | - Zhiqing Chen
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou 510632, China
| | - Yan Yang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou 510632, China
| | - Xiaodan Huang
- Department of Neurology and Stroke Center, The First Affiliated Hospital of Jinan University, Guangzhou 510632, China
| | - Yunwei Fu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou 510632, China
| | - Yue Xi
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China
| | - Song Lin
- Physiology Department, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Qian Tao
- Psychology Department, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Fuqiang Xu
- CAS Key Laboratory of Brain Connectome and Manipulation, The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences (CAS), Shenzhen 518055, China
| | - Kwok-Fai So
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou 510632, China; Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; Center for Brain Science and Brain-Inspired Intelligence, Guangdong-Hong Kong-Macao Greater Bay Area, Guangzhou 510515, China; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510530, China; Key Laboratory of Brain and Cognitive Science, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Chaoran Ren
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou 510632, China; Department of Neurology and Stroke Center, The First Affiliated Hospital of Jinan University, Guangzhou 510632, China; Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, China; Co-innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China; Center for Brain Science and Brain-Inspired Intelligence, Guangdong-Hong Kong-Macao Greater Bay Area, Guangzhou 510515, China; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510530, China.
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