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Cameron S, Donnelly A, Broderick C, Arichi T, Bartsch U, Dazzan P, Elberling J, Godfrey E, Gringras P, Heathcote LC, Joseph D, Wood TC, Pariante C, Rubia K, Flohr C. Mind and skin: Exploring the links between inflammation, sleep disturbance and neurocognitive function in patients with atopic dermatitis. Allergy 2024; 79:26-36. [PMID: 37469218 DOI: 10.1111/all.15818] [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: 03/03/2023] [Revised: 06/06/2023] [Accepted: 07/02/2023] [Indexed: 07/21/2023]
Abstract
Atopic dermatitis (AD) is a chronic, pruritic and inflammatory, dry skin condition with many known comorbidities. These include airway disease, food allergies, atopic eye disease and autoimmune conditions. Furthermore, there is often significant sleep disturbance as well as increased psychological distress and mental health problems. Severe AD therefore often has a significant impact on the quality of life of both patients and their families. In this review we discuss recent findings on the putative links between AD, its association with itch, sleep disturbance and neuropsychiatric morbidity, including the role of inflammation in these conditions. Itch was thought to predominantly drive sleep disruption in AD. We now understand changes in sleep influence immune cell distribution and the associated inflammatory cytokines, which suggests a bidirectional relationship between AD and sleep. We also increasingly recognize inflammation as a key driver in psychological symptoms and disorders. The link between cutaneous, systemic and possible brain inflammation could at least in part be driven by the sleep deprivation and itch-driven neuronal proliferation seen in AD.
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Affiliation(s)
- Shona Cameron
- St John's Institute of Dermatology, King's College London and Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Ali Donnelly
- St John's Institute of Dermatology, King's College London and Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Conor Broderick
- St John's Institute of Dermatology, King's College London and Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Tomoki Arichi
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London and Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Ullrich Bartsch
- Surrey Sleep Research Centre, Department of Clinical and Experimental Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
- UK Dementia Research Institute, Care Research & Technology Centre, Imperial College London and University of Surrey, Guildford, UK
| | - Paola Dazzan
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Jesper Elberling
- Depart of Dermatology and Allergy, Herlev and Gentofte Hospital, Copenhagen, Denmark
| | - Emma Godfrey
- Health Psychology Section, Department of Psychology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Paul Gringras
- Paediatric Sleep Department, Evelina Children's Hospital, King's College London and Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Lauren C Heathcote
- Health Psychology Section, Department of Psychology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Desaline Joseph
- Paediatric Sleep Department, Evelina Children's Hospital, King's College London and Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Tobias C Wood
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Carmine Pariante
- UK Dementia Research Institute, Care Research & Technology Centre, Imperial College London and University of Surrey, Guildford, UK
| | - Katya Rubia
- UK Dementia Research Institute, Care Research & Technology Centre, Imperial College London and University of Surrey, Guildford, UK
| | - Carsten Flohr
- St John's Institute of Dermatology, King's College London and Guy's and St Thomas' NHS Foundation Trust, London, UK
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2
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Chen WZ, Shen TY, Wang M, Yuan L, Wang LH, Ding WQ, Shi XX, Wang XF, Bo BS, Liang ZF, Sun YG. An atlas of itch-associated neural dynamics in the mouse brain. Cell Rep 2023; 42:113304. [PMID: 37862165 DOI: 10.1016/j.celrep.2023.113304] [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: 08/24/2022] [Revised: 08/07/2023] [Accepted: 10/04/2023] [Indexed: 10/22/2023] Open
Abstract
The itch-scratching cycle is mediated by neural dynamics in the brain. However, our understanding of the neural dynamics during this cycle remains limited. In this study, we examine the neural dynamics of 126 mouse brain areas by measuring the calcium signal using fiber photometry. We present numerous response patterns in the mouse brain during the itch-scratching cycle. Interestingly, we find that a group of brain areas exhibit activation only at the end of histamine-induced scratching behavior. Additionally, several brain areas exhibit transient activation at the onset of scratching induced by chloroquine. Both histamine- and chloroquine-induced itch evoke diverse response patterns across the mouse brain. In summary, our study provides a comprehensive dataset for the diverse activity pattern of mouse brain during the itch-scratching cycle, paving the way for further exploration into the neural mechanisms underlying the itch-scratching cycle.
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Affiliation(s)
- Wen-Zhen Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Ting-Yu Shen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Meng Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Lin Yuan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; Department of Orthopaedic Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Lin-Han Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Wen-Qun Ding
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, 19A Yu-quan Road, Beijing 100049, China
| | - Xiao-Xue Shi
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Xiao-Fei Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Bin-Shi Bo
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Zhi-Feng Liang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Yan-Gang Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
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Zhang ZJ, Shao HY, Liu C, Song HL, Wu XB, Cao DL, Zhu M, Fu YY, Wang J, Gao YJ. Descending dopaminergic pathway facilitates itch signal processing via activating spinal GRPR + neurons. EMBO Rep 2023; 24:e56098. [PMID: 37522391 PMCID: PMC10561366 DOI: 10.15252/embr.202256098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 07/10/2023] [Accepted: 07/14/2023] [Indexed: 08/01/2023] Open
Abstract
A11 dopaminergic neurons regulate somatosensory transduction by projecting from the diencephalon to the spinal cord, but the function of this descending projection in itch remained elusive. Here, we report that dopaminergic projection neurons from the A11 nucleus to the spinal dorsal horn (dopaminergicA11-SDH ) are activated by pruritogens. Inhibition of these neurons alleviates itch-induced scratching behaviors. Furthermore, chemogenetic inhibition of spinal dopamine receptor D1-expressing (DRD1+ ) neurons decreases acute or chronic itch-induced scratching. Mechanistically, spinal DRD1+ neurons are excitatory and mostly co-localize with gastrin-releasing peptide (GRP), an endogenous neuropeptide for itch. In addition, DRD1+ neurons form synapses with GRP receptor-expressing (GRPR+ ) neurons and activate these neurons via AMPA receptor (AMPAR). Finally, spontaneous itch and enhanced acute itch induced by activating spinal DRD1+ neurons are relieved by antagonists against AMPAR and GRPR. Thus, the descending dopaminergic pathway facilitates spinal itch transmission via activating DRD1+ neurons and releasing glutamate and GRP, which directly augments GRPR signaling. Interruption of this descending pathway may be used to treat chronic itch.
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Affiliation(s)
- Zhi-Jun Zhang
- Institute of Pain Medicine and Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, Jiangsu, China
- Department of Human Anatomy, School of Medicine, Nantong University, Jiangsu, China
| | - Han-Yu Shao
- Department of Human Anatomy, School of Medicine, Nantong University, Jiangsu, China
| | - Chuan Liu
- Department of Human Anatomy, School of Medicine, Nantong University, Jiangsu, China
| | - Hao-Lin Song
- Department of Human Anatomy, School of Medicine, Nantong University, Jiangsu, China
| | - Xiao-Bo Wu
- Institute of Pain Medicine and Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, Jiangsu, China
| | - De-Li Cao
- Institute of Pain Medicine and Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, Jiangsu, China
| | - Meixuan Zhu
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yuan-Yuan Fu
- Institute of Pain Medicine and Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, Jiangsu, China
| | - Juan Wang
- Department of Human Anatomy, School of Medicine, Nantong University, Jiangsu, China
| | - Yong-Jing Gao
- Institute of Pain Medicine and Special Environmental Medicine, Co-Innovation Center of Neuroregeneration, Nantong University, Jiangsu, China
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Chen R, Xu X, Wang XY, Jia WB, Zhao DS, Liu N, Pang Z, Liu XQ, Zhang Y. The lateral habenula nucleus regulates pruritic sensation and emotion. Mol Brain 2023; 16:54. [PMID: 37370111 DOI: 10.1186/s13041-023-01045-7] [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: 03/28/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
Itch is a complex aversive sensory and emotional experience. As a most upsetting symptom in many dermatological and systemic diseases, it lacks efficient treatments. The lateral habenula nucleus (LHb) encodes negative emotions in the epithalamus and has been implicated in pain and analgesia. Nevertheless, the role of the lateral habenula nucleus in the pruritic sensation and emotion remains elusive. Here we defined the crucial role of glutamatergic neurons within the lateral habenula nucleus (GluLHb) in itch modulation in mice. We established histamine-dependent and histamine-independent models of acute pruritus, as well as the acetone-ether-water (AEW) model of chronic pruritus. We first assessed the effects of pruritogen injection on neural activation in both medial and lateral divisions of LHb in vitro. We then demonstrated that the population activity of GluLHb neurons was increased during the acute itch and chronic itch-induced scratching behaviors in vivo. In addition, electrophysiological data showed that the excitability of GluLHb neurons was enhanced by chronic itch. Chemogenetic suppression of GluLHb neurons disrupted both acute and chronic itch-evoked scratching behaviors. Furthermore, itch-induced conditioned place aversion (CPA) was abolished by GluLHb neuronal inhibition. Finally, we dissected the LHb upstream brain regions. Together, these findings reveal the involvement of LHb in processing both the sensational and emotional components of pruritus and may shed new insights into itch therapy.
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Affiliation(s)
- Rui Chen
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Xiang Xu
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Xin-Yue Wang
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Wen-Bin Jia
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - De-Shan Zhao
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Na Liu
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Zhen Pang
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Xiao-Qing Liu
- School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Yan Zhang
- Department of Neurology, Division of Life Sciences and Medicine, The First Affiliated Hospital of USTC, University of Science and Technology of China, Hefei, Anhui, 230001, China.
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Zhang L, Zou Z, Yu S, Xiao X, Shi Y, Cao W, Liu Y, Zheng H, Zheng Q, Zhou S, Yao J, Deng Y, Yang Q, Chen S, Hao P, Li N, Li Y. Functional connectivity impairment of thalamus-cerebellum-scratching neural circuits in pruritus of chronic spontaneous urticaria. Front Neurosci 2022; 16:1026200. [PMID: 36340791 PMCID: PMC9630740 DOI: 10.3389/fnins.2022.1026200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/06/2022] [Indexed: 11/18/2022] Open
Abstract
Pruritus of chronic spontaneous urticaria (CSU) is one of the most common and irritating sensations that severely affects the quality of life. However, the changes in the functional connectivity (FC) between thalamic subregions and other brain regions have not been fully elucidated. This study aimed to explore the potential changes in brain neural circuits by focusing on various subregions of the thalamus in patients with CSU pruritus to contribute to the understanding of chronic pruritus from the perspective of central mechanisms. A total of 56 patients with CSU and 30 healthy controls (HCs) completed the data analysis. Urticaria Activity Score 7 (UAS7), pruritus visual analog score (VAS-P), Dermatological Life Quality Index (DLQI), and immunoglobulin E (IgE) values were collected to assess clinical symptoms. Seed-based resting-state functional connectivity (rs-FC) analysis was used to assess relevant changes in the neural circuits of the brain. Compared to HCs, seeds within the caudal temporal thalamus (cTtha) on the right side of patients with CSU showed increased rs-FC with the cerebellum anterior lobe (CAL). Seeds within the lateral prefrontal thalamus (lPFtha) on the right side showed increased rs-FC with both CAL and pons, while those within the medial prefrontal thalamus (mPFtha) on the right side showed increased rs-FC with both CAL and the dorsal lateral prefrontal cortex (dlPFC) on the right side. Seeds within the posterior parietal thalamus (PPtha) on the right side showed increased rs-FC with the cerebellum posterior lobe (CPL) on the left side. The UAS7 values and IgE levels were positively correlated with the rs-FC of the right dlPFC. Our results suggest that patients with CSU may exhibit stronger rs-FC alterations between certain thalamic subregions and other brain regions. These changes affect areas of the brain involved in sensorimotor and scratching. Trial registration number [http://www.chictr.org.cn], identifier [ChiCTR1900022994].
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Affiliation(s)
- Leixiao Zhang
- Department of Integrated Traditional and Western Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Zihao Zou
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Siyi Yu
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Xianjun Xiao
- College of Health Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Yunzhou Shi
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Wei Cao
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Ying Liu
- Chinese Medicine Hospital, Chengdu, Sichuan, China
| | - Hui Zheng
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Qianhua Zheng
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Siyuan Zhou
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Junpeng Yao
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Yanli Deng
- Sichuan Second Chinese Medicine Hospital, Chengdu, Sichuan, China
| | - Qian Yang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Sijue Chen
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Pingsheng Hao
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
| | - Ning Li
- Department of Integrated Traditional and Western Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ying Li
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, China
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Zhang J, Zhou H, Li P, Shi H, Sui X, Wang Y, Shi J, Wang L. Hypothalamic response with PKA/CREB signaling is associated with direct cerebroventricular administration of bombesin-induced scratching. Brain Res 2022; 1789:147950. [PMID: 35618015 DOI: 10.1016/j.brainres.2022.147950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 04/29/2022] [Accepted: 05/19/2022] [Indexed: 11/28/2022]
Abstract
Bombesin (BN) is an itch-specific mediator that causes intense itch-scratching activity in mammals. Although most examinations of BN-induced itch processing have focused on the spinal cord, the involvement of central nervous system mechanisms remains unclear. Here, we investigated how relationships among hypothalamic regions regulate BN-mediated itch-scratch processes. We found that intracerebroventricular (i.c.v.) administration of BN (0.04-4 μg) elicited intense itch scratching in mice, whereas BN (0.4-400 μg) administered via intravenous tail injection failed to evoke a scratching response. Additionally, nalfurafine had no significant effects on BN-induced scratching behavior, indicating that central modulation of BN is distinct from histamine-mediated histaminergic itch and chloroquine-mediated non-histaminergic itch signaling pathways. We labeled BN with a fluorescent tag, 7-nitrobenz-2-oxa-1 (NBD), and traced its fluorescence in the hypothalamus for 30 min following i.c.v. NBD-BN administration. Accordingly, we confirmed that i.c.v. administration of BN enhanced c-Fos expression in the dorsal medial nucleus of the hypothalamus, where neuromedin B receptors and gastrin-releasing peptide receptors are highly expressed. Interestingly, in situ injection of BN into the hypothalamus immediately and robustly induced itch-scratching behavior. Moreover, gene transcripts and western blot assay revealed that BN receptor-dependent PKA/CREB signaling was upregulated in the hypothalamus after i.c.v. administration of BN. Consistently, pretreatment with a PKA inhibitor, Rp-cAMP, significantly reduced BN-induced scratching behavior. Our results indicate that the dorsal medial nucleus of the hypothalamus may be a key nucleus in mediating BN-mediated itch and hypothalamic PKA/CREB signaling is involved in regulating BN-mediated itch.
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Affiliation(s)
- Jingxin Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China; The Key Laboratory of Basic Pharmacology of the Educational Minister, Zunyi Medical University, Zunyi, Guizhou 563000, China.
| | - Hu Zhou
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Pengfei Li
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Huaxiang Shi
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Xin Sui
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Yongan Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
| | - Jingshan Shi
- The Key Laboratory of Basic Pharmacology of the Educational Minister, Zunyi Medical University, Zunyi, Guizhou 563000, China.
| | - Liyun Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China.
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Modulation of itch and pain signals processing in ventrobasal thalamus by thalamic reticular nucleus. iScience 2022; 25:103625. [PMID: 35106466 PMCID: PMC8786640 DOI: 10.1016/j.isci.2021.103625] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/16/2021] [Accepted: 12/10/2021] [Indexed: 01/03/2023] Open
Abstract
Thalamic reticular nucleus (TRN) is known to be crucial for dynamically modulating sensory processing. Recently, the functional role of TRN in itch and pain sensation processing has drawn much attention. We found that ventrobasal thalamus (VB) neurons exhibited scratching behavior-related and nociceptive behavior-related neuronal activity changes, and most of VB neurons responsive to pruritic stimulus were also activated by nociceptive stimulus. Inhibition of VB could relieve itch-induced scratching behaviors and pathological pain without affecting basal nociceptive thresholds, and activation of VB could facilitate scratching behaviors. Tracing and electrophysiology recording results showed that VB mainly received inhibitory inputs from ventral TRN. Furthermore, optogenetic activation of TRN-VB projections suppressed scratching behaviors, and ablation of TRN enhanced scratching behaviors. In addition, activation of TRN-VB projections relieved the pathological pain without affecting basal nociceptive thresholds. Thus, our study indicates that TRN modulates itch and pain signals processing via TRN-VB inhibitory projections. VB is involved in both itch and pain signals processing Manipulation of VB or TRN-VB inhibitory projections modulates both itch and pain Enhancing the inhibitory tone might be a strategy for treating itch and pain
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Mamuladze T, Kim BS. The Sensation of Itch: From Biological Discovery to Medical Treatment. J Invest Dermatol 2021; 142:21-22. [PMID: 34801533 DOI: 10.1016/j.jid.2021.10.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 10/19/2022]
Affiliation(s)
- Tornike Mamuladze
- Division of Biology and Biomedical Sciences (DBBS), Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Brian S Kim
- Division of Biology and Biomedical Sciences (DBBS), Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA; Center for the Study of Itch & Sensory Disorders, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA; Division of Dermatology, Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA; Department of Anesthesiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.
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9
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Mu D, Sun YG. Circuit Mechanisms of Itch in the Brain. J Invest Dermatol 2021; 142:23-30. [PMID: 34662562 DOI: 10.1016/j.jid.2021.09.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/21/2021] [Accepted: 09/21/2021] [Indexed: 12/12/2022]
Abstract
Itch is an unpleasant somatic sensation with the desire to scratch, and it consists of sensory, affective, and motivational components. Acute itch serves as a critical protective mechanism because an itch-evoked scratching response will help to remove harmful substances invading the skin. Recently, exciting progress has been made in deciphering the mechanisms of itch at both the peripheral nervous system and the CNS levels. Key neuronal subtypes and circuits have been revealed for ascending transmission and the descending modulation of itch. In this review, we mainly summarize the current understanding of the central circuit mechanisms of itch in the brain.
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Affiliation(s)
- Di Mu
- Department of Anesthesiology, Shanghai General Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yan-Gang Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), Chinese Academy of Sciences, Shanghai, China; Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China.
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10
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Sutaria N, Adawi W, Goldberg R, Roh YS, Choi J, Kwatra SG. Itch: Pathogenesis and treatment. J Am Acad Dermatol 2021; 86:17-34. [PMID: 34648873 DOI: 10.1016/j.jaad.2021.07.078] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 12/19/2022]
Abstract
Itch pathogenesis is broadly characterized into histaminergic and nonhistaminergic pathways and transmitted via 2 main receptor families: G protein-coupled receptors and transient receptor potential channels. In the skin, itch is primarily transmitted by unmyelinated type C and thinly myelinated type Aδ nerve fibers. Crosstalk between the immune and neural systems modulates itch transmission at the skin, spinal cord, and brain. Among the many known pruritogens, Th2 cytokines, such as interleukin-4, interleukin-13, interleukin-31, and thymic stromal lymphopoietin, are particularly important mediators that signal through shared Janus kinase pathways, representing novel targets for novel itch therapeutics. Emerging evidence has also revealed that the opioidergic system is a potent modulator of itch transmission, with increased μ-opioid activity and decreased κ-opioid activity contributing to itch pathogenesis. Optimal management of itch requires that treatment approaches be tailored to specific etiologic itch subtypes. When the etiology is unknown and patients are given a diagnosis of chronic pruritus of unknown origin, treatment should be guided by the presence of Th2 polarization, often reflected by increased blood eosinophils. In the second article of this 2-part series, we outline our current understanding of itch pathogenesis and discuss available and emerging treatments for itch.
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Affiliation(s)
- Nishadh Sutaria
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Waleed Adawi
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Rebecca Goldberg
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Youkyung S Roh
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Justin Choi
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Shawn G Kwatra
- Department of Dermatology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
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11
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Dieckmann G, Borsook D, Moulton E. Neuropathic corneal pain and dry eye: a continuum of nociception. Br J Ophthalmol 2021; 106:1039-1043. [PMID: 33931393 DOI: 10.1136/bjophthalmol-2020-318469] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 12/24/2022]
Abstract
Throughout the body, damage to peripheral nerves normally involved in nociception may produce a constellation of symptoms-including irritation, itchiness and pain. The neurobiological processes involved in corneal symptoms of dry eye (DE) and neuropathic corneal pain (NCP) have not been clearly considered in terms of nociceptive processing. The conventional underlying presumption is that a labelled line principle is responsible; that these distinct perceptions are hard coded by primary afferent inputs to the central nervous system. This presumption oversimplifies the neurobiological mechanisms underlying somatosensory perception. The labelled line perspective that DE represents a chronic pain condition does not make intuitive sense: how can an eye condition that is not painful in most cases be considered a pain condition? Does not chronic pain by definition require pain to be present? On the other hand, NCP, a term that clearly denotes a painful condition, has historically seemed to resonate with clinical significance. Both DE and NCP can share similar features, yet their differentiation is not always clear. As is often the case, clinical terms arise from different disciplines, with DE evolving from ophthalmological findings and NCP inspired by pain neurophysiology. This review evaluates the current definition of these terms, the rationale for their overlap and how the neurophysiology of itch impacts our understanding of these conditions as a continuum of the same disease. Despite the complexity of nociceptive physiology, an understanding of these mechanisms will allow us a more precise therapeutic approach.
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Affiliation(s)
- Gabriela Dieckmann
- Brain and Eye Pain Imaging Lab, Pain and Affective Neuroscience Center, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - David Borsook
- Brain and Eye Pain Imaging Lab, Pain and Affective Neuroscience Center, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital/Harvard Medical School, Boston, Massachusetts, USA
| | - Eric Moulton
- Brain and Eye Pain Imaging Lab, Pain and Affective Neuroscience Center, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital/Harvard Medical School, Boston, Massachusetts, USA
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12
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Lee IS, Kim K, Park HJ, Lee H, Jung WM, Kim DW, Chae Y. Neural Oscillation Associated with Contagious Itch in Patients with Atopic Dermatitis. Brain Sci 2021; 11:brainsci11040438. [PMID: 33805350 PMCID: PMC8067125 DOI: 10.3390/brainsci11040438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 11/16/2022] Open
Abstract
Objective: Itch is an unpleasant sensation associated with an urge to scratch and is a major health care issue associated with atopic dermatitis (AD). Contagious itch, i.e., subjective feelings of itchiness induced by watching others’ scratching behavior, is common in patients with AD. Using electroencephalography, we examined alpha (8–13 Hz) oscillations in sensorimotor areas associated with the desire to scratch in patients with AD. Methods: Thirty-six patients with AD and 34 healthy controls (HCs) participated in this study. They evaluated their itch levels after watching short videos of a model scratching or tapping parts of his body. Neural oscillations were recorded from nine electrodes, including those placed over sensorimotor areas. Time–frequency analysis was used to compare mu rhythm suppression over the sensorimotor areas in response to these videos between patients with AD and HCs. Results: The behavioral test showed that the visual stimuli induced increased feelings of itchiness in patients with AD relative to HCs under the tapping and scratching conditions. The time–frequency analysis revealed that mu rhythm suppression in response to scratching images was significantly prominent in patients with AD, but not in HCs. Conclusion: Patients with AD exhibited increased susceptibility to contagious itch. This phenomenon might be related to enhanced mu rhythm suppression in sensorimotor areas of the brain in these patients. Our findings provide new insight into the neurophysiological basis of itch sensations in patients with AD.
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Affiliation(s)
- In-Seon Lee
- Acupuncture and Meridian Science Research Center, Kyung Hee University, Seoul 02447, Korea; (I.-S.L.); (H.-J.P.); (H.L.); (W.-M.J.)
| | - Kyuseok Kim
- Department of Ophthalmology, Otorhinolaryngology and Dermatology of Korean Medicine, College of Korean Medicine, Kyung Hee University, Seoul 02447, Korea;
| | - Hi-Joon Park
- Acupuncture and Meridian Science Research Center, Kyung Hee University, Seoul 02447, Korea; (I.-S.L.); (H.-J.P.); (H.L.); (W.-M.J.)
| | - Hyangsook Lee
- Acupuncture and Meridian Science Research Center, Kyung Hee University, Seoul 02447, Korea; (I.-S.L.); (H.-J.P.); (H.L.); (W.-M.J.)
| | - Won-Mo Jung
- Acupuncture and Meridian Science Research Center, Kyung Hee University, Seoul 02447, Korea; (I.-S.L.); (H.-J.P.); (H.L.); (W.-M.J.)
| | - Do-Won Kim
- Department of Biomedical Engineering, Chonnam National University, Yeosu 59626, Korea
- Correspondence: (D.-W.K.); (Y.C.)
| | - Younbyoung Chae
- Acupuncture and Meridian Science Research Center, Kyung Hee University, Seoul 02447, Korea; (I.-S.L.); (H.-J.P.); (H.L.); (W.-M.J.)
- Correspondence: (D.-W.K.); (Y.C.)
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13
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Najafi P, Misery L, Carré JL, Ben Salem D, Dufor O. Itch Matrixes. Front Med (Lausanne) 2021; 8:636904. [PMID: 33718409 PMCID: PMC7943862 DOI: 10.3389/fmed.2021.636904] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/25/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Peyman Najafi
- Univ Brest, LIEN, Brest, France.,Paris-Saclay Institute of Neuroscience, Centre National de la Recherche Scientifique/Université Paris-Saclay, Gif-sur-Yvette, France
| | - Laurent Misery
- Univ Brest, LIEN, Brest, France.,University Hospital of Brest, Department of Dermatology, Brest, France
| | | | - Douraied Ben Salem
- Univ Brest, LATIM, INSERM UMR, Brest, France.,University Hospital of Brest, Department of Radiology, Brest, France
| | - Olivier Dufor
- Univ Brest, LIEN, Brest, France.,L@bISEN Yncréa Ouest, ISEN, Brest, France
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14
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Increased grey matter volume and associated resting-state functional connectivity in chronic spontaneous urticaria: A structural and functional MRI study. J Neuroradiol 2021; 48:236-242. [PMID: 33549611 DOI: 10.1016/j.neurad.2021.01.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/28/2020] [Accepted: 01/26/2021] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND PURPOSE Chronic itch is one of the most common irritating sensations, yet its mechanisms have not been fully elucidated. Although some studies have revealed relationships between itching and brain function, the structural changes in the brain induced by chronic itching, such as those accompanying chronic spontaneous urticaria (CSU), remain unclear. In this study, we aimed to explore the potential changes in brain structure and the associated functional circuitry in CSU patients to generate insights to aid chronic itch management. METHODS Forty CSU patients and forty healthy controls (HCs) were recruited. Seven-day urticaria activity score (UAS7) values were collected to evaluate clinical symptoms. Voxel-based morphometry (VBM) and seed-based resting-state functional connectivity (rs-FC) analysis were used to assess structural changes in the brain and associated changes in functional circuitry. RESULTS Compared with HCs, CSU patients had significantly increased grey matter (GM) volume in the right premotor cortex, left fusiform cortex, and cerebellum. UAS7 values were positively associated with GM volume in the left fusiform cortex. In CSU patients relative to HCs, the left fusiform cortex as extracted by VBM analysis demonstrated decreased functional connectivity with the right orbitofrontal cortex, medial prefrontal cortex (mPFC), premotor cortex, primary motor cortex (MI), and cerebellum and increased functional connectivity with the right posterior insular cortex, primary somatosensory cortex (SI), and secondary somatosensory cortex (SII). The left cerebellum as extracted from VBM analysis demonstrated decreased functional connectivity with the right supplementary motor area (SMA) and MI in CSU patients relative to HCs. CONCLUSIONS Our findings indicate that patients suffering from chronic itching conditions, such as CSU, are likely to demonstrate altered GM volume in some brain regions. These changes may affect not only the sensorimotor area but also brain regions associated with cognitive function.
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15
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Misery L. Pruriplastic Itch-A Novel Pathogenic Concept in Chronic Pruritus. Front Med (Lausanne) 2021; 7:615118. [PMID: 33553207 PMCID: PMC7854543 DOI: 10.3389/fmed.2020.615118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/22/2020] [Indexed: 11/24/2022] Open
Abstract
The International Association for the Study of Pain (IASP) defined three descriptors for pain: nociceptive pain is “pain that arises from actual or threatened damage to non neural tissue and is due to the activation of nociceptors”; neuropathic pain is “pain caused by a lesion or disease of the somatosensory nervous system”; and nociplastic pain is “pain that arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain.” Based on clinical and pathophysiological arguments, a similar definition of “pruriplastic pruritus” should be made. Pruriplastic pruritus would include psychogenic pruritus, as well as some cases of pruritus ani, vulvar pruritus, sensitive skin or other poorly understood cases of pruritus. This new descriptor of itch could serve as systematic screening for altered pruriceptive function in patients who suffer from chronic itch and it may also help in defining better tailored treatment by identifying patients who are likely to respond better to centrally rather than to peripherally targeted therapies.
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16
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Coninx S. Strong representationalism and bodily sensations: Reliable causal covariance and biological function. PHILOSOPHICAL PSYCHOLOGY 2020. [DOI: 10.1080/09515089.2020.1858476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Sabrina Coninx
- Institute for Philosophy II, Ruhr University Bochum, Bochum, Germany
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17
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Najafi P, Dufor O, Ben Salem D, Misery L, Carré JL. Itch processing in the brain. J Eur Acad Dermatol Venereol 2020; 35:1058-1066. [PMID: 33145804 DOI: 10.1111/jdv.17029] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 09/17/2020] [Accepted: 10/02/2020] [Indexed: 01/04/2023]
Abstract
Itch is a sensation defined as the urge to scratch. The central mechanisms of itch are being increasingly studied. These studies are usually based on experimental itch induction methods, which can be classified into the following categories: histamine-induced, induction by other non-histamine chemicals (e.g. cowhage), physically induced (e.g. electrical) and mentally induced (e.g. audio-visual). Because pain has been more extensively studied, some extrapolations to itch can be proposed and verified by experiments. Recent studies suggest that the itch-processing network in the brain could be disrupted in certain diseases. This disruption could be related to the implication of new regions or the exclusion of already engaged brain regions from itch-processing network in the brain.
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Affiliation(s)
| | - O Dufor
- LIEN, Univ Brest, Brest, France.,LabISEN Yncréa Ouest ISEN, Brest, France
| | - D Ben Salem
- Univ Brest, LaTIM, INSERM, UMR 1101, Brest, France.,University Hospital of Brest, Brest, France
| | - L Misery
- LIEN, Univ Brest, Brest, France.,University Hospital of Brest, Brest, France
| | - J-L Carré
- LIEN, Univ Brest, Brest, France.,University Hospital of Brest, Brest, France
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18
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Granot M, Yakov S, Ramon M. Enhanced Itch Intensity Is Associated with Less Efficient Descending Inhibition Processing for Itch But Not Pain Attenuation in Chronic Dermatology Patients. PAIN MEDICINE 2020; 21:2538-2545. [DOI: 10.1093/pm/pnz263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Objectives
The study aims were 1) to investigate the direction of mutual inhibitory pathways on itch intensity by utilizing conditioned pain modulation paradigms for pain and itch attenuation and 2) to explore whether itch severity is affected by the individual pain sensitivity profile, as well as pain scores reported during the tests and the past week.
Design
Cross-sectional.
Setting
Testing was conducted at the Department of Dermatology, Rambam Health Care Campus.
Subjects
Forty patients suffering from chronic skin disorders associated with itch and treated in the Dermatology Clinic at Rambam Health Care Campus participated in the study.
Methods
Efficacy of descending inhibition was evaluated by two conditioned pain modulation (CPM) paradigms: by pruriception (CPMItch) induced by cold and heat as counterstimuli to inhibit itch intensity and by nociception (CPMPain). Severity and interference of clinical pain were assessed using the Brief Pain Inventory (BPI).
Results
Robust CPMItch responses were obtained following the various noxious stimulations. No associations were observed between CPMPain and CPMItch, itch severity, skin disease severity, and clinical pain symptoms. According to the linear regression model, itch severity was independently associated with less efficient CPMItch (B = –0.750, P < 0.001) and more efficient CPMPain (B = 0.031, P = 0.016), which affects itch in opposing manners.
Conclusions
Findings indicate that the intrinsic capacity to inhibit pain and itch by exposure to exogenous noxious stimuli autonomously affects itch intensity in an opposing manner. These findings may shed new light on the mutual mechanistic similarity and dissimilarity between pain and itch and their hierarchy.
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Affiliation(s)
- Michal Granot
- The Laboratory of Clinical Neurophysiology, the Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
- The Faculty of Social Welfare and Health Studies, University of Haifa, Haifa, Israel
| | - Sarit Yakov
- Department of Dermatology, Rambam Health Care Campus, Haifa, Israel
| | - Michal Ramon
- Department of Dermatology, Rambam Health Care Campus, Haifa, Israel
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Affiliation(s)
| | - Douraied Ben Salem
- Neuroradiology, University Hospital of Brest, 29609 Brest Cedex, France; Latim, Inserm, UMR 1101, Univ Brest (UBO), 29200 Brest, France
| | - Laurent Misery
- LIEN, EA4685, Univ Brest (UBO), 29200 Brest, France; Department of Dermatology, University Hospital of Brest, 29609 Brest Cedex, France
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20
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Posterior Thalamic Nucleus Mediates Facial Histaminergic Itch. Neuroscience 2020; 444:54-63. [PMID: 32750381 DOI: 10.1016/j.neuroscience.2020.07.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 07/13/2020] [Accepted: 07/27/2020] [Indexed: 11/24/2022]
Abstract
Itch induces a desire to scratch and leads to skin damage in some severe conditions. Much progress has been made in the peripheral and spinal level, and recent findings suggested that we need to focus on the central circuitry mechanism. However, the functional role of the thalamus in itch signal processing remains largely unknown. We showed that the posterior thalamic nucleus (Po) played a vital role in modulating facial histaminergic itch signal processing. We found that the calcium signal of Po neurons was increased during the histaminergic itch-induced scratching behavior in the cheek model, and pharmacogenetic suppression of Po neurons reduced the scratching behaviors. Retrograde mapping results suggested that the Po receives information from the somatosensory cortex, motor cortex, parabrachial nucleus (PBN), the principal sensory trigeminal nucleus (PrV) and the spinal trigeminal nucleus (SpV), which participate in itch signal transmission from head and body. Thus, our study indicates that the Po is critical in modulating facial histaminergic itch signal processing.
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21
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Abstract
Itch, in particular chronic forms, has been widely recognized as an important clinical problem, but much less is known about the mechanisms of itch in comparison with other sensory modalities such as pain. Recently, considerable progress has been made in dissecting the circuit mechanisms of itch at both the spinal and supraspinal levels. Major components of the spinal neural circuit underlying both chemical and mechanical itch have now been identified, along with the circuits relaying ascending transmission and the descending modulation of itch. In this review, we summarize the progress in elucidating the neural circuit mechanism of itch at spinal and supraspinal levels.
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Affiliation(s)
- Xiao-Jun Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
- University of Chinese Academy of Sciences, 19A Yu-quan Road, 100049, Beijing, China
| | - Yan-Gang Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China.
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, 201210, Shanghai, China.
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22
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Najafi P, Carré JL, Ben Salem D, Brenaut E, Misery L, Dufor O. Central mechanisms of itch: A systematic literature review and meta-analysis. J Neuroradiol 2019; 47:450-457. [PMID: 31809769 DOI: 10.1016/j.neurad.2019.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/18/2019] [Accepted: 11/25/2019] [Indexed: 12/11/2022]
Abstract
In recent years, studying the central mechanism of itch has gained momentum. However, a proper meta-analysis has not been conducted in this domain. In this study, we tried to respond to this need. A systematic search and a meta-analysis were carried out to estimate the central mechanism of itch. The itch matrix comprises the thalamus and the parietal, secondary somatosensory, insular and cingulate cortices. We have shown that the basal ganglia (BG) play an important role in itch reduction. Finally, we explored itch processing in AD patients and observed that the itch matrix in these patients was different. In conclusion, this is the first meta-analysis on the central mechanisms of itch perception and processing. Our study demonstrated that different modalities of itch induction can produce a common pattern of activity in the brain and provided further insights into understanding the underlying nature of itch central perception.
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Affiliation(s)
| | - Jean-Luc Carré
- LIEN, université Brest, 29200 Brest, France; University Hospital of Brest, 29200 Brest, France
| | - Douraied Ben Salem
- LaTIM, Inserm UMR 1101, université Brest, 29200 Brest, France; University Hospital of Brest, 29200 Brest, France
| | - Emilie Brenaut
- LIEN, université Brest, 29200 Brest, France; University Hospital of Brest, 29200 Brest, France
| | - Laurent Misery
- LIEN, université Brest, 29200 Brest, France; University Hospital of Brest, 29200 Brest, France.
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23
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Yosipovitch G, Rosen JD, Hashimoto T. Itch: From mechanism to (novel) therapeutic approaches. J Allergy Clin Immunol 2019; 142:1375-1390. [PMID: 30409247 DOI: 10.1016/j.jaci.2018.09.005] [Citation(s) in RCA: 183] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/27/2018] [Accepted: 09/07/2018] [Indexed: 12/13/2022]
Abstract
Itch is a common sensory experience that is prevalent in patients with inflammatory skin diseases, as well as in those with systemic and neuropathic conditions. In patients with these conditions, itch is often severe and significantly affects quality of life. Itch is encoded by 2 major neuronal pathways: histaminergic (in acute itch) and nonhistaminergic (in chronic itch). In the majority of cases, crosstalk existing between keratinocytes, the immune system, and nonhistaminergic sensory nerves is responsible for the pathophysiology of chronic itch. This review provides an overview of the current understanding of the molecular, neural, and immune mechanisms of itch: beginning in the skin, proceeding to the spinal cord, and eventually ascending to the brain, where itch is processed. A growing understanding of the mechanisms of chronic itch is expanding, as is our pipeline of more targeted topical and systemic therapies. Our therapeutic armamentarium for treating chronic itch has expanded in the last 5 years, with developments of topical and systemic treatments targeting the neural and immune systems.
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Affiliation(s)
- Gil Yosipovitch
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center Miller School of Medicine University of Miami, Miami, Fla.
| | - Jordan Daniel Rosen
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center Miller School of Medicine University of Miami, Miami, Fla
| | - Takashi Hashimoto
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center Miller School of Medicine University of Miami, Miami, Fla
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24
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Mueller SM, Mueller F, Reinhardt J, Itin P, Navarini A, Stippich C, Borgwardt S. Assessment of the impact of sex in intensity, skin flares and central processing of histaminergic itch—A pilot study. Exp Dermatol 2019; 28:1493-1500. [DOI: 10.1111/exd.14021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/25/2019] [Accepted: 08/07/2019] [Indexed: 12/21/2022]
Affiliation(s)
| | - Felix Mueller
- Department of Psychiatry University of Basel Basel Switzerland
| | - Julia Reinhardt
- Division of Diagnostic and Interventional Neuroradiology Department of Radiology University Hospital Basel University of Basel Basel Switzerland
- Department of Neuroradiology Clinical Neuroscience Center University Hospital Zurich University of Zurich Zurich Switzerland
| | - Peter Itin
- Department of Dermatology University of Basel Basel Switzerland
| | | | - Christoph Stippich
- Division of Diagnostic and Interventional Neuroradiology Department of Radiology University Hospital Basel University of Basel Basel Switzerland
- Department of Neuroradiology Clinical Neuroscience Center University Hospital Zurich University of Zurich Zurich Switzerland
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25
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Ständer S, Spellman MC, Kwon P, Yosipovitch G. The NK1 receptor antagonist serlopitant for treatment of chronic pruritus. Expert Opin Investig Drugs 2019; 28:659-666. [PMID: 31272246 DOI: 10.1080/13543784.2019.1638910] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Introduction: Pruritus is a common symptom associated with several potential underlying causes, including both dermatologic and systemic diseases; it can also occur without an identifiable cause. Current treatment options are limited and most patients experience impaired quality of life. Serlopitant is a neurokinin 1 (NK1) receptor antagonist under development for the treatment of pruritus associated with various dermatologic conditions and chronic pruritus of unknown origin. Areas covered: This review describes the epidemiology and unmet needs of patients with chronic pruritus, focusing specifically on patients with prurigo nodularis, psoriatic itch, and chronic pruritus of unknown origin; the rationale for targeting the NK1 receptor for treatment of chronic pruritus; and the clinical development of serlopitant, including efficacy and safety data from completed phase II studies. Expert opinion: There is an unmet need for novel, safe, and effective therapies to treat chronic pruritus. Serlopitant has shown promising efficacy, safety, and tolerability across different patient populations, including adolescents and elderly patients. In contrast to less convenient administration options, serlopitant is a once-daily oral tablet, which is expected to facilitate compliance.
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Affiliation(s)
- Sonja Ständer
- a Dermatology and Neurodermatology, Center for Chronic Pruritus, Department of Dermatology, University Hospital Münster , Münster , Germany
| | - Mary C Spellman
- b Department of Clinical Development, Menlo Therapeutics Inc , Redwood City , CA , USA
| | - Paul Kwon
- b Department of Clinical Development, Menlo Therapeutics Inc , Redwood City , CA , USA
| | - Gil Yosipovitch
- c Miami Itch Center, Dr Phillip Frost Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami , Miami , FL , USA
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26
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Ständer S, Yosipovitch G. Substance P and neurokinin 1 receptor are new targets for the treatment of chronic pruritus. Br J Dermatol 2019; 181:932-938. [PMID: 31016733 DOI: 10.1111/bjd.18025] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Chronic pruritus is a distressing symptom associated with various dermatological conditions and systemic diseases. Current treatment options are often inadequate, resulting in impaired quality of life for many patients. An understanding of the underlying mechanisms of itch across pruritic conditions is important for development of effective, targeted treatments for chronic pruritus. OBJECTIVES To provide an overview of the pathogenesis of chronic pruritus, focusing on the role of substance P (SP) and neurokinin 1 receptor (NK1 R) in itch signalling, and to describe data supporting NK1 R antagonism as a potential strategy for the treatment of chronic pruritus. METHODS A PubMed search was conducted to determine what data were available that investigated the role of SP and NK1 R in itch signalling. RESULTS SP is a neuropeptide that is a mediator of itch signalling. One of the target receptors for SP is NK1 R, which is expressed in the central nervous system and on multiple cell types involved in the initiation and transmission of itch. Studies demonstrating that SP and NK1 R are overexpressed across multiple chronic itch-inducing conditions and that NK1 R antagonism disrupts itch signalling and reduces itch provide a rationale for targeting this pathway as a potential treatment of chronic pruritus across multiple diseases. CONCLUSIONS A large and growing body of evidence, including recent phase II clinical studies of NK1 R antagonists, demonstrate that SP and NK1 R play an important role in itch signalling. Additional studies are ongoing to further evaluate the use of NK1 R antagonists for the treatment of chronic pruritus. What's already known about this topic? Chronic pruritus has a significant impact on quality of life. Current treatment options for chronic pruritus are inadequate. Substance P (SP) and neurokinin 1 receptor (NK1 R) have been shown to play a role in itch signalling, and may be a rational target for addressing chronic pruritus. NK1 R antagonists are being evaluated as potential treatment for chronic pruritus. What does this study add? This review provides a compilation of the most up-to-date data elucidating the role of SP and NK1 R in itch signalling, which supports targeting this pathway as a potential treatment of chronic pruritus. NK1 R antagonism disrupts itch signalling and reduces itch. A summary of the latest data on NK1 R antagonists in the treatment of pruritus is provided.
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Affiliation(s)
- S Ständer
- Center for Chronic Pruritus, Department of Dermatology, University Hospital Münster, Münster, Germany
| | - G Yosipovitch
- Miami Itch Center, Dr Phillip Frost Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL, U.S.A
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27
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Jones O, Schindler I, Holle H. Transcranial magnetic stimulation over contralateral primary somatosensory cortex disrupts perception of itch intensity. Exp Dermatol 2018; 28:1380-1384. [DOI: 10.1111/exd.13803] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/13/2018] [Accepted: 10/11/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Olivia Jones
- Department of PsychologyUniversity of Hull Hull UK
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Ehling S, Butler A, Thi S, Ghashghaei HT, Bäumer W. To scratch an itch: Establishing a mouse model to determine active brain areas involved in acute histaminergic itch. IBRO Rep 2018; 5:67-73. [PMID: 30364768 PMCID: PMC6197726 DOI: 10.1016/j.ibror.2018.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/13/2018] [Indexed: 12/30/2022] Open
Abstract
The specific histamine H4 receptor agonist ST-1006 induces acute itch in mice. Histaminergic itch increases neuronal activity in the medial habenula. Selective H4R activation in the skin increases neuronal activity in the medial habenula.
Background Strategies to efficiently control itch require a deep understanding of the underlying mechanisms. Several areas in the brain involved in itch and scratching responses have been postulated, but the central mechanisms that drive pruritic responses are still unknown. Histamine is recognized as a major mediator of itch in humans, and has been the most frequently used stimulus as an experimental pruritogen for brain imaging of itch. Objective Histaminergic itch via histamine and the selective histamine H4 receptor (H4R) agonist, ST-1006, recruit brain nuclei through c-fos activation and activate specific areas in the brain. Methods An acute itch model was established in c-fos-EGFP transgenic mice using ST-1006 and histamine. Coronal brain sections were stained for c-fos immunoreactivity and the forebrain was mapped for density of c-fos + nuclei. Results Histamine and ST-1006 significantly increased scratching response in c-fos-EGFP mice compared to vehicle controls. Mapping c-fos immunostained brain sections revealed neuronal activity in the cortex, striatum, hypothalamus, thalamus, amygdala, and the midbrain. Conclusions Histaminergic itch and selective H4R activation significantly increased the density of c-fos + nuclei in the medial habenula (MHb). Thus, the MHb may be a new target to investigate and subsequently develop novel mechanism-based strategies to treat itch and possibly provide a locus for pharmacological control of pruritus.
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Affiliation(s)
- Sarah Ehling
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA.,Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Ashley Butler
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA
| | - Stephanie Thi
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA
| | - H Troy Ghashghaei
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA
| | - Wolfgang Bäumer
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, NC, USA.,Institute of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
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29
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Wang Y, Fang J, Song P, Bao Y, Song W, Liu J, Lang C, Jorgenson K, Jung M, Shen D, Li S, Sun R, Ding X, Yang J, Meng X, Wang N, Yan Z, Yan Y, Kong Q, Dong Y, Cui F, Tu Y, Cui B, Kong J. The Dysfunction of the Cerebellum and Its Cerebellum-Reward-Sensorimotor Loops in Chronic Spontaneous Urticaria. CEREBELLUM (LONDON, ENGLAND) 2018; 17:507-516. [PMID: 29574551 PMCID: PMC6126981 DOI: 10.1007/s12311-018-0933-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Chronic spontaneous urticaria (CSU) is a common itchy skin disease. Despite its prevalence, the neuropathology of CSU is uncertain. In this study, we explored resting state functional connectivity (rs-FC) changes in CSU, as well as how the symptom changes following intervention can modulate rs-FC. Forty patients and 40 healthy controls (HCs) were recruited. Following an intervention, 32 patients participated in a second scan approximately 6 weeks after the first scan. Compared with healthy controls, CSU subjects exhibited higher regional homogeneity (ReHo) values in the cerebellum, which were positively associated with urticaria activity scores over 7 days (UAS7) at baseline. After an intervention accompanied with clinical improvement, we found that ReHo values decreased at the cerebellum and increased at the bilateral primary somatosensory cortex (SI)/primary motor cortex (MI)/supplementary motor area (SMA). Using the cerebellum as a seed, CSU subjects exhibited increased rs-FC with reward regions when compared with HCs and exhibited decreased rs-FC at the right orbitofrontal cortex and right sensorimotor region following the intervention. The improvement rate values were positively associated with reduced rs-FC values in the two regions. Using the cluster of SI/MI/SMA as a seed, CSU patients exhibited decreased rs-FC with the left putamen, caudate, accumbens, and thalamus following the intervention. These results demonstrate the altered cerebellar activity and cerebellum-reward-sensorimotor loops in CSU.
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Affiliation(s)
- Yuming Wang
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Jiliang Fang
- Department of Radiology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Ping Song
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Yan Bao
- Department of Radiology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Wenwen Song
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Jiao Liu
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
- National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, 350122, China
| | - Courtney Lang
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Kristen Jorgenson
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Minyoung Jung
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Dong Shen
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Shasha Li
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Ruirui Sun
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Xu Ding
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Jiao Yang
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Xiao Meng
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Ning Wang
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Zhifang Yan
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Yuhe Yan
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Qian Kong
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Ying Dong
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Fangyuan Cui
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Yiheng Tu
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Bingnan Cui
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China.
| | - Jian Kong
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA.
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Abstract
Itch is an unpleasant sensation that initiates scratching behavior. The itch-scratch reaction is a complex phenomenon that implicates supraspinal structures required for regulation of sensory, emotional, cognitive, and motivational aspects. However, the central mechanisms underlying the processing of itch and the interplay of the supraspinal regions and spinal cord in regulating itch-scratch processes are poorly understood. Here, we have shown that the neural projections from anterior cingulate cortex (ACC) to dorsal medial striatum (DMS) constitute a critical circuit element for regulating itch-related behaviors in the brains of male C57BL/6J mice. Moreover, we demonstrate that ACC-DMS projections selectively modulate histaminergic, but not nonhistaminergic, itch-related behavior. Furthermore, photoactivation of ACC-DMS projections has also no significant effects on pain behavior induced by thermal, mechanical, and chemical stimuli except for a relief on inflammatory pain evoked by formalin and complete Freund's adjuvant. We further demonstrate that the dorsal spinal cord exerts an inhibitory effect on itch signal from ACC-DMS projections through B5-I neurons, which represent a population of spinal inhibitory interneurons that mediate the inhibition of itch. Therefore, this study presents the first evidence that the ACC-DMS projections modulate histaminergic itch-related behavior and reveals an interplay between the supraspinal and spinal levels in histaminergic itch regulation.SIGNIFICANCE STATEMENT This study reveals that the projections from anterior cingulate cortex (ACC) to dorsal medial striatum (DMS) constitute a supraspinal circuit for modulation of histaminergic, but not nonhistaminergic, itch. Manipulation of ACC-DMS projections has no effect on acute pain sensation. Furthermore, the dorsal spinal cord exerts an inhibitory effect on itch signal from ACC-DMS projections through B5-I neurons. Understanding the supraspinal itch circuits is of great significance in the development of new therapies for chronic itch-related intractable diseases.
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31
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Wang Y, Fang JL, Cui B, Liu J, Song P, Lang C, Bao Y, Sun R, Xu C, Ding X, Yan Z, Yan Y, Kong Q, Kong J. The functional and structural alterations of the striatum in chronic spontaneous urticaria. Sci Rep 2018; 8:1725. [PMID: 29379058 PMCID: PMC5789061 DOI: 10.1038/s41598-018-19962-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/11/2018] [Indexed: 12/16/2022] Open
Abstract
The brain has long been known to be the regulation center of itch, but the neuropathology of chronic itch, such as chronic spontaneous urticaria (CSU), remains unclear. Thus, we aimed to explore the brain areas involved in the pathophysiology of CSU in hopes that our results may provide valuable insights into the treatment of chronic itch conditions. 40 CSU patients and 40 healthy controls (HCs) were recruited. Urticaria activity scores 7 (UAS7) were collected to evaluate patient’s clinical symptoms. Amplitude of low frequency fluctuations (ALFF), voxel-based morphometry (VBM), and seed-based resting-state functional connectivity (rs-FC) analysis were used to assess brain activity and related plasticity. Compared with HCs, CSU patients exhibited 1) higher ALFF values in the right ventral striatum / putamen, which were positively associated with clinical symptoms as measured by UAS7; 2) gray matter volume (GMV) increase in the right ventral striatum and putamen; and 3) decreased rs-FC between the right ventral striatum and the right occipital cortex and between the right putamen and the left precentral gyrus. Using multiple-modality brain imaging tools, we demonstrated the dysfunction of the striatum in CSU. Our results may provide valuable insights into the neuropathology and development of chronic itch.
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Affiliation(s)
- Yuming Wang
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China. .,Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA.
| | - Ji-Liang Fang
- Department of Radiology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Bingnan Cui
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Jiao Liu
- Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA.,National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, 350122, China
| | - Ping Song
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Courtney Lang
- Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Yan Bao
- Department of Radiology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Ruirui Sun
- Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Chenchen Xu
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Xu Ding
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Zhifang Yan
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Yuhe Yan
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Qian Kong
- Department of Dermatology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, 100053, China
| | - Jian Kong
- Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA.
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Mu D, Deng J, Liu KF, Wu ZY, Shi YF, Guo WM, Mao QQ, Liu XJ, Li H, Sun YG. A central neural circuit for itch sensation. Science 2017; 357:695-699. [DOI: 10.1126/science.aaf4918] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 07/07/2017] [Indexed: 12/17/2022]
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Schut C, Mochizuki H, Grossman SK, Lin AC, Conklin CJ, Mohamed FB, Gieler U, Kupfer J, Yosipovitch G. Brain Processing of Contagious Itch in Patients with Atopic Dermatitis. Front Psychol 2017; 8:1267. [PMID: 28790959 PMCID: PMC5524890 DOI: 10.3389/fpsyg.2017.01267] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/11/2017] [Indexed: 11/13/2022] Open
Abstract
Several studies show that itch and scratching cannot only be induced by pruritogens like histamine or cowhage, but also by the presentation of certain (audio-) visual stimuli like pictures on crawling insects or videos showing other people scratching. This phenomenon is coined "Contagious itch" (CI). Due to the fact that CI is more profound in patients with the chronic itchy skin disease atopic dermatitis (AD), we believe that it is highly relevant to study brain processing of CI in this group. Knowledge on brain areas involved in CI in AD-patients can provide us with useful hints regarding non-invasive treatments that AD-patients could profit from when they are confronted with itch-inducing situations in daily life. Therefore, this study investigated the brain processing of CI in AD-patients. 11 AD-patients underwent fMRI scans during the presentation of an itch inducing experimental video (EV) and a non-itch inducing control video (CV). Perfusion based brain activity was measured using arterial spin labeling functional MRI. As expected, the EV compared to the CV led to an increase in itch and scratching (p < 0.05). CI led to a significant increase in brain activity in the supplementary motor area, left ventral striatum and right orbitofrontal cortex (threshold: p < 0.001; cluster size k > 50). Moreover, itch induced by watching the EV was by trend correlated with activity in memory-related regions including the temporal cortex and the (pre-) cuneus as well as the posterior operculum, a brain region involved in itch processing (threshold: p < 0.005; cluster size k > 50). These findings suggest that the fronto-striatal circuit, which is associated with the desire to scratch, might be a target region for non-invasive treatments in AD patients.
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Affiliation(s)
- Christina Schut
- Institute of Medical Psychology, Justus-Liebig-UniversityGiessen, Germany
| | - Hideki Mochizuki
- Department of Dermatology, Lewis Katz School of Medicine at Temple University, PhiladelphiaPA, United States
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center, Miller School of Medicine, University of Miami, MiamiFL, United States
| | - Shoshana K. Grossman
- Department of Dermatology, Lewis Katz School of Medicine at Temple University, PhiladelphiaPA, United States
| | - Andrew C. Lin
- Department of Dermatology, Lewis Katz School of Medicine at Temple University, PhiladelphiaPA, United States
| | - Christopher J. Conklin
- Department of Radiology, Jefferson Integrated Magnetic Resonance Imaging Center, Thomas Jefferson University, PhiladelphiaPA, United States
| | - Feroze B. Mohamed
- Department of Radiology, Jefferson Integrated Magnetic Resonance Imaging Center, Thomas Jefferson University, PhiladelphiaPA, United States
| | - Uwe Gieler
- Department of Dermatology, University Hospital of Giessen and MarburgGiessen, Germany
| | - Joerg Kupfer
- Institute of Medical Psychology, Justus-Liebig-UniversityGiessen, Germany
| | - Gil Yosipovitch
- Department of Dermatology and Cutaneous Surgery and Miami Itch Center, Miller School of Medicine, University of Miami, MiamiFL, United States
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Mueller SM, Hogg S, Mueller JM, McKie S, Itin P, Reinhardt J, Griffiths CE, Kleyn CE. Functional magnetic resonance imaging in dermatology: The skin, the brain and the invisible. Exp Dermatol 2017; 26:845-853. [DOI: 10.1111/exd.13305] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Simon M. Mueller
- Department of Dermatology; University Hospital Basel; Basel Switzerland
- Dermatology Centre; The Manchester Academic Health Science Centre; The University of Manchester; Manchester UK
| | - Samuel Hogg
- Department of Dermatology; University Hospital Basel; Basel Switzerland
| | - Jannis M. Mueller
- Department of Neurology; Kantonsspital Muensterlingen; Muensterlingen Switzerland
| | - Shane McKie
- Neuroscience and Psychiatry Unit; The Manchester Academic Health Science Centre; The University of Manchester; Manchester UK
| | - Peter Itin
- Dermatology Centre; The Manchester Academic Health Science Centre; The University of Manchester; Manchester UK
| | - Julia Reinhardt
- Division of Diagnostic & Interventional Neuroradiology; University Hospital Basel; Basel Switzerland
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Mochizuki H, Schut C, Nattkemper LA, Yosipovitch G. Brain mechanism of itch in atopic dermatitis and its possible alteration through non-invasive treatments. Allergol Int 2017; 66:14-21. [PMID: 27688121 DOI: 10.1016/j.alit.2016.08.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 08/30/2016] [Indexed: 01/19/2023] Open
Abstract
Atopic dermatitis (AD) is a common chronic skin disease that is characterized by intense pruritus and has high impairment of quality of life. AD is often described as "the itch that rashes, rather than the rash that itches". Several studies suggest that mechanisms of central modulation play an important role in the development and maintenance of chronic itch. Therefore, treating the neurosensory aspects of itch is an important part in the management of chronic itch. However, little attention has been paid to the role of the central nervous system in the processing of itch in AD. Targeting itch-related anatomical structures in the brain with non-invasive treatments such as psychological interventions and transcranial Direct Current Stimulation (tDCS) could have an antipruritic effect in AD. Therefore, in this review article, we discuss the current progress in brain imaging research of itch, as well as the efficacy of non-invasive interventions for itch relief in this patient group.
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Affiliation(s)
- Hideki Mochizuki
- Department of Dermatology, Lewis Katz School of Medicine, Philadelphia, PA, USA; Temple Itch Center, Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Christina Schut
- Institute of Medical Psychology, Justus-Liebig-University, Giessen, Germany
| | - Leigh A Nattkemper
- Department of Dermatology, Lewis Katz School of Medicine, Philadelphia, PA, USA; Temple Itch Center, Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Gil Yosipovitch
- Department of Dermatology and Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, USA.
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Abstract
This chapter summarizes recent findings regarding the central transmission of acute and chronic itch. Itch is transduced by cutaneous pruriceptors that transmit signals to neurons in the superficial spinal cord. Spinal itch-signaling circuits utilize several neuropeptides whose receptors represent novel targets to block itch transmission. Itch is relieved by scratching, which activates spinal interneurons to inhibit itch-transmitting neurons. Spinal itch transmission is also thought to be modulated by descending pathways. Itch is transmitted rostrally via ascending pathways to activate a variety of brain regions involved in sensory discrimination of affective and motor responses to itch. The pathophysiological mechanisms of chronic itch are poorly understood but likely involve sensitization of itch-signaling pathways and/or dysfunction of itch-inhibitory circuits. Improved understanding of central itch mechanisms has identified a number of novel targets for the development of antipruritic treatment strategies.
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Nakagawa K, Mochizuki H, Koyama S, Tanaka S, Sadato N, Kakigi R. A transcranial direct current stimulation over the sensorimotor cortex modulates the itch sensation induced by histamine. Clin Neurophysiol 2016; 127:827-832. [DOI: 10.1016/j.clinph.2015.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 07/02/2015] [Accepted: 07/05/2015] [Indexed: 10/23/2022]
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