1
|
Follansbee T, Le Chang H, Iodi Carstens M, Guan Y, Carstens E, Dong X. Optotagging and characterization of GABAergic rostral ventromedial medulla (RVM) neurons. Mol Pain 2024; 20:17448069241270295. [PMID: 39054310 DOI: 10.1177/17448069241270295] [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: 07/27/2024] Open
Abstract
The transmission of nociceptive and pruriceptive signals in the spinal cord is greatly influenced by descending modulation from brain areas such as the rostral ventromedial medulla (RVM). Within the RVM three classes of neurons have been discovered which are relevant to spinal pain modulation, the On, Off, and Neutral cells. These neurons were discovered due to their functional response to nociceptive stimulation. On cells are excited, Off cells are inhibited, and Neutral cells have no response to noxious stimulation. Since these neurons are identified by functional response characteristics it has been difficult to molecularly identify them. In the present study, we leverage our ability to perform optotagging within the RVM to determine whether RVM On, Off, and Neutral cells are GABAergic. We found that 27.27% of RVM On cells, 47.37% of RVM Off cells, and 42.6% of RVM Neutral cells were GABAergic. These results demonstrate that RVM On, Off, and Neutral cells represent a heterogeneous population of neurons and provide a reliable technique for the molecular identification of these neurons.
Collapse
Affiliation(s)
- Taylor Follansbee
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Henry Le Chang
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Mirela Iodi Carstens
- Department of Neurobiology, Physiology, and Behavior, University of California Davis, Davis, CA, USA
| | - Yun Guan
- Department of Neurological Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Earl Carstens
- Department of Neurobiology, Physiology, and Behavior, University of California Davis, Davis, CA, USA
| | - Xinzhong Dong
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA
| |
Collapse
|
2
|
Yao J, Li X, Wu GY, Wu B, Long JH, Wang PJ, Liu SL, Gao J, Sui JF. The Anterior Insula and its Projection to the Prelimbic Cortex are Involved in the Regulation of 5-HT-Induced Itch. Neurosci Bull 2023; 39:1807-1822. [PMID: 37553505 PMCID: PMC10661608 DOI: 10.1007/s12264-023-01093-y] [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: 12/10/2022] [Accepted: 04/12/2023] [Indexed: 08/10/2023] Open
Abstract
Itch is an unpleasant sensation that urges people and animals to scratch. Neuroimaging studies on itch have yielded extensive correlations with diverse cortical and subcortical regions, including the insular lobe. However, the role and functional specificity of the insular cortex (IC) and its subdivisions in itch mediation remains unclear. Here, we demonstrated by immunohistochemistry and fiber photometry tests, that neurons in both the anterior insular cortex (AIC) and the posterior insular cortex (PIC) are activated during acute itch processes. Pharmacogenetic experiments revealed that nonselective inhibition of global AIC neurons, or selective inhibition of the activity of glutaminergic neurons in the AIC, reduced the scratching behaviors induced by intradermal injection of 5-hydroxytryptamine (5-HT), but not those induced by compound 48/80. However, both nonselective inhibition of global PIC neurons and selective inhibition of glutaminergic neurons in the PIC failed to affect the itching-scratching behaviors induced by either 5-HT or compound 48/80. In addition, pharmacogenetic inhibition of AIC glutaminergic neurons effectively blocked itch-associated conditioned place aversion behavior, and inhibition of AIC glutaminergic neurons projecting to the prelimbic cortex significantly suppressed 5-HT-evoked scratching. These findings provide preliminary evidence that the AIC is involved, at least partially via aversive emotion mediation, in the regulation of 5-HT-, but not compound 48/80-induced itch.
Collapse
Affiliation(s)
- Juan Yao
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China
| | - Xuan Li
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China
| | - Guang-Yan Wu
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China
| | - Bing Wu
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China
| | - Jun-Hui Long
- Department of Dermatology, The 958th Army Hospital of the People's Liberation Army, Chongqing, 400020, China
| | - Pu-Jun Wang
- Department of Dermatology, The 958th Army Hospital of the People's Liberation Army, Chongqing, 400020, China
| | - Shu-Lei Liu
- Department of Dermatology, The 958th Army Hospital of the People's Liberation Army, Chongqing, 400020, China
| | - Jie Gao
- State Key Laboratory of Trauma, Burns and Combined Injury, Army Medical Centre of the PLA, Institute of Surgery Research, Daping Hospital, Army Medical University, Chongqing, 400042, China.
| | - Jian-Feng Sui
- Experimental Center of Basic Medicine, Army Medical University, Chongqing, 400038, China.
- Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing, 400038, China.
| |
Collapse
|
3
|
Zhang Z, Shao H, Liu C, Song H, Wu X, Cao D, Zhu M, Fu Y, Wang J, Gao Y. 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] [Grants] [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.
Collapse
Affiliation(s)
- Zhi‐Jun Zhang
- Institute of Pain Medicine and Special Environmental Medicine, Co‐Innovation Center of NeuroregenerationNantong UniversityJiangsuChina
- Department of Human Anatomy, School of MedicineNantong UniversityJiangsuChina
| | - Han‐Yu Shao
- Department of Human Anatomy, School of MedicineNantong UniversityJiangsuChina
| | - Chuan Liu
- Department of Human Anatomy, School of MedicineNantong UniversityJiangsuChina
| | - Hao‐Lin Song
- Department of Human Anatomy, School of MedicineNantong UniversityJiangsuChina
| | - Xiao‐Bo Wu
- Institute of Pain Medicine and Special Environmental Medicine, Co‐Innovation Center of NeuroregenerationNantong UniversityJiangsuChina
| | - De‐Li Cao
- Institute of Pain Medicine and Special Environmental Medicine, Co‐Innovation Center of NeuroregenerationNantong UniversityJiangsuChina
| | - Meixuan Zhu
- University of North Carolina at Chapel HillChapel HillNCUSA
| | - Yuan‐Yuan Fu
- Institute of Pain Medicine and Special Environmental Medicine, Co‐Innovation Center of NeuroregenerationNantong UniversityJiangsuChina
| | - Juan Wang
- Department of Human Anatomy, School of MedicineNantong UniversityJiangsuChina
| | - Yong‐Jing Gao
- Institute of Pain Medicine and Special Environmental Medicine, Co‐Innovation Center of NeuroregenerationNantong UniversityJiangsuChina
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
Ren X, Liu S, Virlogeux A, Kang SJ, Brusch J, Liu Y, Dymecki SM, Han S, Goulding M, Acton D. Identification of an essential spinoparabrachial pathway for mechanical itch. Neuron 2023; 111:1812-1829.e6. [PMID: 37023756 PMCID: PMC10446756 DOI: 10.1016/j.neuron.2023.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 01/31/2023] [Accepted: 03/08/2023] [Indexed: 04/08/2023]
Abstract
The sensation of itch is a protective response that is elicited by either mechanical or chemical stimuli. The neural pathways for itch transmission in the skin and spinal cord have been characterized previously, but the ascending pathways that transmit sensory information to the brain to evoke itch perception have not been identified. Here, we show that spinoparabrachial neurons co-expressing Calcrl and Lbx1 are essential for generating scratching responses to mechanical itch stimuli. Moreover, we find that mechanical and chemical itch are transmitted by separate ascending pathways to the parabrachial nucleus, where they engage separate populations of FoxP2PBN neurons to drive scratching behavior. In addition to revealing the architecture of the itch transmission circuitry required for protective scratching in healthy animals, we identify the cellular mechanisms underlying pathological itch by showing the ascending pathways for mechanical and chemical itch function cooperatively with the FoxP2PBN neurons to drive chronic itch and hyperknesis/alloknesis.
Collapse
Affiliation(s)
- Xiangyu Ren
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA; Biology Graduate Program, Division of Biological Sciences, University of California San Diego, 9500 Gilman Dr, San Diego, CA 92093, USA
| | - Shijia Liu
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA; Biology Graduate Program, Division of Biological Sciences, University of California San Diego, 9500 Gilman Dr, San Diego, CA 92093, USA
| | - Amandine Virlogeux
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Sukjae J Kang
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Jeremy Brusch
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA
| | - Yuanyuan Liu
- NIDCR, National Institute of Health, 35A Convent Drive, Bethesda, MD 20892, USA
| | - Susan M Dymecki
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Sung Han
- Peptide Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA.
| | - Martyn Goulding
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA.
| | - David Acton
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA 92037, USA
| |
Collapse
|
6
|
Wu XB, Zhu Q, Gao MH, Yan SX, Gu PY, Zhang PF, Xu ML, Gao YJ. Excitatory Projections from the Prefrontal Cortex to Nucleus Accumbens Core D1-MSNs and κ Opioid Receptor Modulate Itch-Related Scratching Behaviors. J Neurosci 2023; 43:1334-1347. [PMID: 36653189 PMCID: PMC9987576 DOI: 10.1523/jneurosci.1359-22.2023] [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: 07/11/2022] [Revised: 12/28/2022] [Accepted: 01/06/2023] [Indexed: 01/20/2023] Open
Abstract
Itch is an uncomfortable and complex sensation that elicits the desire to scratch. The nucleus accumbens (NAc) activity is important in driving sensation, motivation, and emotion. Excitatory afferents from the medial prefrontal cortex (mPFC), amygdala, and hippocampus are crucial in tuning the activity of dopamine receptor D1-expressing and D2-expressing medium spiny neurons (Drd1-MSN and Drd2-MSN) in the NAc. However, a cell-type and neural circuity-based mechanism of the NAc underlying acute itch remains unclear. We found that acute itch induced by compound 48/80 (C48/80) decreased the intrinsic membrane excitability in Drd1-MSNs, but not in Drd2-MSNs, in the NAc core of male mice. Chemogenetic activation of Drd1-MSNs alleviated C48/80-induced scratching behaviors but not itch-related anxiety-like behaviors. In addition, C48/80 enhanced the frequency of spontaneous EPSCs (sEPSCs) and reduced the paired-pulse ratio (PPR) of electrical stimulation-evoked EPSCs in Drd1-MSNs. Furthermore, C48/80 increased excitatory synaptic afferents to Drd1-MSNs from the mPFC, not from the basolateral amygdala (BLA) or ventral hippocampus (vHipp). Consistently, the intrinsic excitability of mPFC-NAc projecting pyramidal neurons was increased after C48/80 treatment. Chemogenetic inhibition of mPFC-NAc excitatory synaptic afferents relieved the scratching behaviors. Moreover, pharmacological activation of κ opioid receptor (KOR) in the NAc core suppressed C48/80-induced scratching behaviors, and the modulation of KOR activity in the NAc resulted in the changes of presynaptic excitatory inputs to Drd1-MSNs in C48/80-treated mice. Together, these results reveal the neural plasticity in synapses of NAc Drd1-MSNs from the mPFC underlying acute itch and indicate the modulatory role of the KOR in itch-related scratching behaviors.SIGNIFICANCE STATEMENT Itch stimuli cause strongly scratching desire and anxiety in patients. However, the related neural mechanisms remain largely unclear. In the present study, we demonstrated that the pruritogen compound 48/80 (C48/80) shapes the excitability of dopamine receptor D1-expressing medium spiny neurons (Drd1-MSNs) in the nucleus accumbens (NAc) core and the glutamatergic synaptic afferents from medial prefrontal cortex (mPFC) to these neurons. Chemogenetic activation of Drd1-MSNs or inhibition of mPFC-NAc excitatory synaptic afferents relieves the scratching behaviors. In addition, pharmacological activation of κ opioid receptor (KOR) in the NAc core alleviates C48/80-induced itch. Thus, targeting mPFC-NAc Drd1-MSNs or KOR may provide effective treatments for itch.
Collapse
Affiliation(s)
- Xiao-Bo Wu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Qian Zhu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Ming-Hui Gao
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Sheng-Xiang Yan
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Pan-Yang Gu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Peng-Fei Zhang
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Meng-Lin Xu
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| | - Yong-Jing Gao
- Institute of Pain Medicine and Special Environmental Medicine, Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu 226019, China
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Li J, Bai Y, Liang Y, Zhang Y, Zhao Q, Ge J, Li D, Zhu Y, Cai G, Tao H, Wu S, Huang J. Parvalbumin Neurons in Zona Incerta Regulate Itch in Mice. Front Mol Neurosci 2022; 15:843754. [PMID: 35299695 PMCID: PMC8920991 DOI: 10.3389/fnmol.2022.843754] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 02/08/2022] [Indexed: 12/20/2022] Open
Abstract
Pain and itch are intricately entangled at both circuitry and behavioral levels. Emerging evidence indicates that parvalbumin (PV)-expressing neurons in zona incerta (ZI) are critical for promoting nocifensive behaviors. However, the role of these neurons in itch modulation remains elusive. Herein, by combining FOS immunostaining, fiber photometry, and chemogenetic manipulation, we reveal that ZI PV neurons act as an endogenous negative diencephalic modulator for itch processing. Morphological data showed that both histamine and chloroquine stimuli induced FOS expression in ZI PV neurons. The activation of these neurons was further supported by the increased calcium signal upon scratching behavior evoked by acute itch. Behavioral data further indicated that chemogenetic activation of these neurons reduced scratching behaviors related to histaminergic and non-histaminergic acute itch. Similar neural activity and modulatory role of ZI PV neurons were seen in mice with chronic itch induced by atopic dermatitis. Together, our study provides direct evidence for the role of ZI PV neurons in regulating itch, and identifies a potential target for the remedy of chronic itch.
Collapse
Affiliation(s)
- Jiaqi Li
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Yang Bai
- Department of Neurosurgery, General Hospital of Northern Theater Command, Shenyang, China
| | - Yi Liang
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Yiwen Zhang
- The Cadet Team 6 of School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Qiuying Zhao
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Junye Ge
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Dangchao Li
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Yuanyuan Zhu
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Guohong Cai
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Huiren Tao
- Department of Spine Surgery, Shenzhen University General Hospital, Shenzhen, China
| | - Shengxi Wu
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| | - Jing Huang
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medical University, Xi’an, China
| |
Collapse
|