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Tiwari N, Qiao LY. Sex Differences in Visceral Pain and Comorbidities: Clinical Outcomes, Preclinical Models, and Cellular and Molecular Mechanisms. Cells 2024; 13:834. [PMID: 38786056 PMCID: PMC11119472 DOI: 10.3390/cells13100834] [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: 03/19/2024] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024] Open
Abstract
Sexual dimorphism of visceral pain has been documented in clinics and experimental animal models. Aside from hormones, emerging evidence suggests the sex-differential intrinsic neural regulation of pain generation and maintenance. According to the International Association for the Study of Pain (IASP) and the American College of Gastroenterology (ACG), up to 25% of the population have visceral pain at any one time, and in the United States 10-15 percent of adults suffer from irritable bowel syndrome (IBS). Here we examine the preclinical and clinical evidence of sex differences in visceral pain focusing on IBS, other forms of bowel dysfunction and IBS-associated comorbidities. We summarize preclinical animal models that provide a means to investigate the underlying molecular mechanisms in the sexual dimorphism of visceral pain. Neurons and nonneuronal cells (glia and immune cells) in the peripheral and central nervous systems, and the communication of gut microbiota and neural systems all contribute to sex-dependent nociception and nociplasticity in visceral painful signal processing. Emotion is another factor in pain perception and appears to have sexual dimorphism.
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Affiliation(s)
- Namrata Tiwari
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
| | - Liya Y. Qiao
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
- Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
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2
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Zhao S, Umpierre AD, Wu LJ. Tuning neural circuits and behaviors by microglia in the adult brain. Trends Neurosci 2024; 47:181-194. [PMID: 38245380 PMCID: PMC10939815 DOI: 10.1016/j.tins.2023.12.003] [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: 07/07/2023] [Revised: 11/04/2023] [Accepted: 12/21/2023] [Indexed: 01/22/2024]
Abstract
Microglia are the primary immune cells of the CNS, contributing to both inflammatory damage and tissue repair in neurological disorder. In addition, emerging evidence highlights the role of homeostatic microglia in regulating neuronal activity, interacting with synapses, tuning neural circuits, and modulating behaviors. Herein, we review how microglia sense and regulate neuronal activity through synaptic interactions, thereby directly engaging with neural networks and behaviors. We discuss current studies utilizing microglial optogenetic and chemogenetic approaches to modulate adult neural circuits. These manipulations of microglia across different CNS regions lead to diverse behavioral consequences. We propose that spatial heterogeneity of microglia-neuron interaction lays the groundwork for understanding diverse functions of microglia in neural circuits and behaviors.
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Affiliation(s)
- Shunyi Zhao
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | | | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN, USA; Department of Immunology, Mayo Clinic, Rochester, MN, USA; Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.
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3
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Weyer MP, Strehle J, Schäfer MKE, Tegeder I. Repurposing of pexidartinib for microglia depletion and renewal. Pharmacol Ther 2024; 253:108565. [PMID: 38052308 DOI: 10.1016/j.pharmthera.2023.108565] [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: 09/28/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/07/2023]
Abstract
Pexidartinib (PLX3397) is a small molecule receptor tyrosine kinase inhibitor of colony stimulating factor 1 receptor (CSF1R) with moderate selectivity over other members of the platelet derived growth factor receptor family. It is approved for treatment of tenosynovial giant cell tumors (TGCT). CSF1R is highly expressed by microglia, which are macrophages of the central nervous system (CNS) that defend the CNS against injury and pathogens and contribute to synapse development and plasticity. Challenged by pathogens, apoptotic cells, debris, or inflammatory molecules they adopt a responsive state to propagate the inflammation and eventually return to a homeostatic state. The phenotypic switch may fail, and disease-associated microglia contribute to the pathophysiology in neurodegenerative or neuropsychiatric diseases or long-lasting detrimental brain inflammation after brain, spinal cord or nerve injury or ischemia/hemorrhage. Microglia also contribute to the growth permissive tumor microenvironment of glioblastoma (GBM). In rodents, continuous treatment for 1-2 weeks via pexidartinib food pellets leads to a depletion of microglia and subsequent repopulation from the remaining fraction, which is aided by peripheral monocytes that search empty niches for engraftment. The putative therapeutic benefit of such microglia depletion or forced renewal has been assessed in almost any rodent model of CNS disease or injury or GBM with heterogeneous outcomes, but a tendency of partial beneficial effects. So far, microglia monitoring e.g. via positron emission imaging is not standard of care for patients receiving Pexidartinib (e.g. for TGCT), so that the depletion and repopulation efficiency in humans is still largely unknown. Considering the virtuous functions of microglia, continuous depletion is likely no therapeutic option but short-lasting transient partial depletion to stimulate microglia renewal or replace microglia in genetic disease in combination with e.g. stem cell transplantation or as part of a multimodal concept in treatment of glioblastoma appears feasible. The present review provides an overview of the preclinical evidence pro and contra microglia depletion as a therapeutic approach.
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Affiliation(s)
- Marc-Philipp Weyer
- Institute of Clinical Pharmacology, Goethe-University Frankfurt, Faculty of Medicine, Frankfurt, Germany
| | - Jenny Strehle
- Department of Anesthesiology, University Medical Center Johannes Gutenberg-University Mainz, Germany
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center Johannes Gutenberg-University Mainz, Germany
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Goethe-University Frankfurt, Faculty of Medicine, Frankfurt, Germany.
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Namba MD, Xie Q, Barker JM. Advancing the preclinical study of comorbid neuroHIV and substance use disorders: Current perspectives and future directions. Brain Behav Immun 2023; 113:453-475. [PMID: 37567486 PMCID: PMC10528352 DOI: 10.1016/j.bbi.2023.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/23/2023] [Accepted: 07/30/2023] [Indexed: 08/13/2023] Open
Abstract
Human immunodeficiency virus (HIV) remains a persistent public health concern throughout the world. Substance use disorders (SUDs) are a common comorbidity that can worsen treatment outcomes for people living with HIV. The relationship between HIV infection and SUD outcomes is likely bidirectional, making clear interrogation of neurobehavioral outcomes challenging in clinical populations. Importantly, the mechanisms through which HIV and addictive drugs disrupt homeostatic immune and CNS function appear to be highly overlapping and synergistic within HIV-susceptible reward and motivation circuitry in the central nervous system. Decades of animal research have revealed invaluable insights into mechanisms underlying the pathophysiology SUDs and HIV, although translational studies examining comorbid SUDs and HIV are very limited due to the technical challenges of modeling HIV infection preclinically. In this review, we discuss preclinical animal models of HIV and highlight key pathophysiological characteristics of each model, with a particular emphasis on rodent models of HIV. We then review the implementation of these models in preclinical SUD research and identify key gaps in knowledge in the field. Finally, we discuss how cutting-edge behavioral neuroscience tools, which have revealed key insights into the neurobehavioral mechanisms of SUDs, can be applied to preclinical animal models of HIV to reveal potential, novel treatment avenues for comorbid HIV and SUDs. Here, we argue that future preclinical SUD research would benefit from incorporating comorbidities such as HIV into animal models and would facilitate the discovery of more refined, subpopulation-specific mechanisms and effective SUD prevention and treatment targets.
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Affiliation(s)
- Mark D Namba
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Qiaowei Xie
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Jacqueline M Barker
- Department of Pharmacology & Physiology, College of Medicine, Drexel University, Philadelphia, PA, USA.
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Douglass JD, Ness KM, Valdearcos M, Wyse-Jackson A, Dorfman MD, Frey JM, Fasnacht RD, Santiago OD, Niraula A, Banerjee J, Robblee M, Koliwad SK, Thaler JP. Obesity-associated microglial inflammatory activation paradoxically improves glucose tolerance. Cell Metab 2023; 35:1613-1629.e8. [PMID: 37572666 PMCID: PMC10528677 DOI: 10.1016/j.cmet.2023.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/09/2023] [Accepted: 07/19/2023] [Indexed: 08/14/2023]
Abstract
Hypothalamic gliosis associated with high-fat diet (HFD) feeding increases susceptibility to hyperphagia and weight gain. However, the body-weight-independent contribution of microglia to glucose regulation has not been determined. Here, we show that reducing microglial nuclear factor κB (NF-κB) signaling via cell-specific IKKβ deletion exacerbates HFD-induced glucose intolerance despite reducing body weight and adiposity. Conversely, two genetic approaches to increase microglial pro-inflammatory signaling (deletion of an NF-κB pathway inhibitor and chemogenetic activation through a modified Gq-coupled muscarinic receptor) improved glucose tolerance independently of diet in both lean and obese rodents. Microglial regulation of glucose homeostasis involves a tumor necrosis factor alpha (TNF-α)-dependent mechanism that increases activation of pro-opiomelanocortin (POMC) and other hypothalamic glucose-sensing neurons, ultimately leading to a marked amplification of first-phase insulin secretion via a parasympathetic pathway. Overall, these data indicate that microglia regulate glucose homeostasis in a body-weight-independent manner, an unexpected mechanism that limits the deterioration of glucose tolerance associated with obesity.
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Affiliation(s)
- John D Douglass
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Kelly M Ness
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Martin Valdearcos
- The Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Alice Wyse-Jackson
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Mauricio D Dorfman
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Jeremy M Frey
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Rachael D Fasnacht
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Olivia D Santiago
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Anzela Niraula
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Jineta Banerjee
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - Megan Robblee
- The Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Suneil K Koliwad
- The Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
| | - Joshua P Thaler
- UW Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98109, USA.
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Zhao S, Zheng J, Wang L, Umpierre AD, Parusel S, Xie M, Dheer A, Ayasoufi K, Johnson AJ, Richardson JR, Wu LJ. Chemogenetic manipulation of CX3CR1 + cells transiently induces hypolocomotion independent of microglia. Mol Psychiatry 2023; 28:2857-2871. [PMID: 37365239 PMCID: PMC10906107 DOI: 10.1038/s41380-023-02128-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 05/20/2023] [Accepted: 06/13/2023] [Indexed: 06/28/2023]
Abstract
Chemogenetic approaches using Designer Receptors Exclusively Activated by Designer Drugs (DREADD, a family of engineered GPCRs) were recently employed in microglia. Here, we used Cx3cr1CreER/+:R26hM4Di/+ mice to express Gi-DREADD (hM4Di) on CX3CR1+ cells, comprising microglia and some peripheral immune cells, and found that activation of hM4Di on long-lived CX3CR1+ cells induced hypolocomotion. Unexpectedly, Gi-DREADD-induced hypolocomotion was preserved when microglia were depleted. Consistently, specific activation of microglial hM4Di cannot induce hypolocomotion in Tmem119CreER/+:R26hM4Di/+ mice. Flow cytometric and histological analysis showed hM4Di expression in peripheral immune cells, which may be responsible for the hypolocomotion. Nevertheless, depletion of splenic macrophages, hepatic macrophages, or CD4+ T cells did not affect Gi-DREADD-induced hypolocomotion. Our study demonstrates that rigorous data analysis and interpretation are needed when using Cx3cr1CreER/+ mouse line to manipulate microglia.
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Affiliation(s)
- Shunyi Zhao
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | - Jiaying Zheng
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | - Lingxiao Wang
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA
| | | | | | - Manling Xie
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Aastha Dheer
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | | | - Aaron J Johnson
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
- Department of Immunology, Mayo Clinic, Rochester, MN, USA
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN, USA
| | - Jason R Richardson
- Department of Environmental Health Science, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, USA
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN, USA.
- Department of Immunology, Mayo Clinic, Rochester, MN, USA.
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA.
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Hayashi Y, Otsuji J, Oshima E, Hitomi S, Ni J, Urata K, Shibuta I, Iwata K, Shinoda M. Microglia cause structural remodeling of noradrenergic axon in the trigeminal spinal subnucleus caudalis after infraorbital nerve injury in rats. Brain Behav Immun Health 2023; 30:100622. [PMID: 37101903 PMCID: PMC10123072 DOI: 10.1016/j.bbih.2023.100622] [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: 12/22/2022] [Revised: 04/01/2023] [Accepted: 04/07/2023] [Indexed: 04/28/2023] Open
Abstract
The dysfunction of descending noradrenergic (NAergic) modulation in second-order neurons has long been observed in neuropathic pain. In clinical practice, antidepressants that increase noradrenaline levels in the synaptic cleft are used as first-line agents, although adequate analgesia has not been occasionally achieved. One of the hallmarks of neuropathic pain in the orofacial regions is microglial abnormalities in the trigeminal spinal subnucleus caudalis (Vc). However, until now, the direct interaction between descending NAergic system and Vc microglia in orofacial neuropathic pain has not been explored. We found that reactive microglia ingested the dopamine-β-hydroxylase (DβH)-positive fraction, NAergic fibers, in the Vc after infraorbital nerve injury (IONI). Major histocompatibility complex class I (MHC-I) was upregulated in Vc microglia after IONI. Interferon-γ (IFNγ) was de novo induced in trigeminal ganglion (TG) neurons following IONI, especially in C-fiber neurons, which conveyed to the central terminal of TG neurons. Gene silencing of IFNγ in the TG reduced MHC-I expression in the Vc after IONI. Intracisternal administration of exosomes from IFNγ-stimulated microglia elicited mechanical allodynia and a decrease in DβH in the Vc, which did not occur when exosomal MHC-I was knocked down. Similarly, in vivo MHC-I knockdown in Vc microglia attenuated the development of mechanical allodynia and a decrease in DβH in the Vc after IONI. These results show that microglia-derived MHC-I causes a decrease in NAergic fibers, culminating in orofacial neuropathic pain.
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Affiliation(s)
- Yoshinori Hayashi
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, 101-8310, Japan
- Corresponding author. Department of Physiology, Nihon University School of Dentistry, 1-8-13, Kandasurugadai, Chiyoda-ku, Tokyo, 101-8301, Japan.
| | - Jo Otsuji
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Eri Oshima
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Suzuro Hitomi
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy in the Ministry of Industry and Information Technology, Department of Biology, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Kentaro Urata
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Ikuko Shibuta
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Koichi Iwata
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Masamichi Shinoda
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, 101-8310, Japan
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Ghazisaeidi S, Muley MM, Salter MW. Neuropathic Pain: Mechanisms, Sex Differences, and Potential Therapies for a Global Problem. Annu Rev Pharmacol Toxicol 2023; 63:565-583. [PMID: 36662582 DOI: 10.1146/annurev-pharmtox-051421-112259] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The study of chronic pain continues to generate ever-increasing numbers of publications, but safe and efficacious treatments for chronic pain remain elusive. Recognition of sex-specific mechanisms underlying chronic pain has resulted in a surge of studies that include both sexes. A predominant focus has been on identifying sex differences, yet many newly identified cellular mechanisms and alterations in gene expression are conserved between the sexes. Here we review sex differences and similarities in cellular and molecular signals that drive the generation and resolution of neuropathic pain. The mix of differences and similarities reflects degeneracy in peripheral and central signaling processes by which neurons, immune cells, and glia codependently drive pain hypersensitivity. Recent findings identifying critical signaling nodes foreshadow the development of rationally designed, broadly applicable analgesic strategies. However, the paucity of effective, safe pain treatments compels targeted therapies as well to increase therapeutic options that help reduce the global burden of suffering.
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Affiliation(s)
- Shahrzad Ghazisaeidi
- Program in Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada;
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- University of Toronto Centre for the Study of Pain, Toronto, Ontario, Canada
| | - Milind M Muley
- Program in Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada;
- University of Toronto Centre for the Study of Pain, Toronto, Ontario, Canada
| | - Michael W Salter
- Program in Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada;
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- University of Toronto Centre for the Study of Pain, Toronto, Ontario, Canada
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Marwari S, Kowalski C, Martemyanov KA. Exploring pharmacological inhibition of G q/11 as an analgesic strategy. Br J Pharmacol 2022; 179:5196-5208. [PMID: 35900909 PMCID: PMC9633401 DOI: 10.1111/bph.15935] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/06/2022] [Accepted: 07/14/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND AND PURPOSE Misuse of opioids has greatly affected our society. One potential solution is to develop analgesics that act at targets other than opioid receptors. These can be used either as stand-alone therapeutics or to improve the safety profile of opioid drugs. Previous research showed that activation of Gq/11 proteins by G-protein coupled receptors has pro-nociceptive properties, suggesting that blockade of Gq/11 signalling could be beneficial for pain control. The aim of this study was to test this hypothesis pharmacologically by using potent and selective Gq/11 inhibitor YM-254890. EXPERIMENTAL APPROACH We used a series of behavioural assays to evaluate the acute responses of mice to painful thermal stimulation while administering YM-254890 alone and in combination with morphine. We then used electrophysiological recordings to evaluate the effects of YM-254890 on the excitability of dorsal root ganglion (DRG) nociceptor neurons. KEY RESULTS We found that systemic administration of YM-254890 produced anti-nociceptive effects and also augmented morphine analgesia in both hotplate and tail flick paradigms. However, it also caused substantial inhibition of locomotion, which may limit its therapeutic utility. To circumvent these issues, we explored the local administration of YM-254890. Intrathecal injections of YM-254890 produced lasting analgesia in a tail flick test and greatly augmented the anti-nociceptive effects of morphine without any significant effects on locomotor behaviour. Electrophysiological studies showed that YM-254890 reduced the excitability of DRG nociceptors and augmented their opioid-induced inhibition. CONCLUSION AND IMPLICATIONS These findings indicate that pharmacological inhibition of Gq/11 could be explored as an analgesic strategy.
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Affiliation(s)
- Subhi Marwari
- Department of NeuroscienceThe Scripps Research InstituteJupiterFloridaUSA
| | - Cody Kowalski
- Department of NeuroscienceThe Scripps Research InstituteJupiterFloridaUSA
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Decreased PPARgamma in the trigeminal spinal subnucleus caudalis due to neonatal injury contributes to incision-induced mechanical allodynia in female rats. Sci Rep 2022; 12:19314. [PMID: 36369249 PMCID: PMC9652333 DOI: 10.1038/s41598-022-23832-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022] Open
Abstract
Whisker pad skin incision in infancy causes the prolongation of mechanical allodynia after re-incision in adulthood. A recent study also proposed the importance of sex differences in pain signaling in the spinal cord. However, the sex difference in re-incision-induced mechanical allodynia in the orofacial region is not fully understood. In the rats that experienced neonatal injury in the whisker pad skin, the mechanical allodynia in the whisker pad was significantly prolonged after re-incision in adulthood compared to sham injury in infancy. No significant sex differences were observed in the duration of mechanical allodynia. The duration of mechanical allodynia in male rats was shortened by intracisternal administration of minocycline. However, minocycline had no effects on the duration of mechanical allodynia in female rats. In contrast, intracisternal administration of pioglitazone markedly suppressed mechanical allodynia in female rats after re-incision. Following re-incision, the number of peroxisome proliferator-activated receptor gamma (PPARgamma)-positive cells were reduced in the trigeminal spinal subnucleus caudalis (Vc) in female rats that experienced neonatal injury. Immunohistochemical analyses revealed that PPARgamma was predominantly expressed in Vc neurons. Pioglitazone increased the number of PPARgamma-positive Vc neurons in female rats whose whisker pad skin was incised in both infancy and adulthood stages. Pioglitazone also upregulated heme oxygenase 1 and downregulated NR1 subunit in the Vc in female rats after re-incision. Together, PPARgamma signaling in Vc neurons is a female-specific pathway for whisker pad skin incision-induced mechanical allodynia.
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Jiang B, Ding T, Guo C, Bai X, Cao D, Wu X, Sha W, Jiang M, Wu L, Gao Y. NFAT1 Orchestrates Spinal Microglial Transcription and Promotes Microglial Proliferation via c-MYC Contributing to Nerve Injury-Induced Neuropathic Pain. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2201300. [PMID: 35892263 PMCID: PMC9507349 DOI: 10.1002/advs.202201300] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 06/17/2022] [Indexed: 05/17/2023]
Abstract
Peripheral nerve injury-induced spinal microglial proliferation plays a pivotal role in neuropathic pain. So far, key intracellular druggable molecules involved in this process are not identified. The nuclear factor of activated T-cells (NFAT1) is a master regulator of immune cell proliferation. Whether and how NFAT1 modulates spinal microglial proliferation during neuropathic pain remain unknown. Here it is reported that NFAT1 is persistently upregulated in microglia after spinal nerve ligation (SNL), which is regulated by TET2-mediated DNA demethylation. Global or microglia-specific deletion of Nfat1 attenuates SNL-induced pain and decreases excitatory synaptic transmission of lamina II neurons. Furthermore, deletion of Nfat1 decreases microglial proliferation and the expression of multiple microglia-related genes, such as cytokines, transmembrane signaling receptors, and transcription factors. Particularly, SNL increases the binding of NFAT1 with the promoter of Itgam, Tnf, Il-1b, and c-Myc in the spinal cord. Microglia-specific overexpression of c-MYC induces pain hypersensitivity and microglial proliferation. Finally, inhibiting NFAT1 and c-MYC by intrathecal injection of inhibitor or siRNA alleviates SNL-induced neuropathic pain. Collectively, NFAT1 is a hub transcription factor that regulates microglial proliferation via c-MYC and guides the expression of the activated microglia genome. Thus, NFAT1 may be an effective target for treating neuropathic pain.
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Affiliation(s)
- Bao‐Chun Jiang
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
| | - Ting‐Yu Ding
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
| | - Chang‐Yun Guo
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
| | - Xue‐Hui Bai
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
| | - De‐Li Cao
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
| | - Xiao‐Bo Wu
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
| | - Wei‐Lin Sha
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
| | - Ming Jiang
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
| | - Long‐Jun Wu
- Department of NeurologyMayo ClinicRochesterMN55905USA
| | - Yong‐Jing Gao
- Institute of Pain Medicine and Special Environmental MedicineCo‐innovation Center of NeuroregenerationNantong UniversityJiangsu226019China
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Imado E, Sun S, Abawa AR, Tahara T, Kochi T, Huynh TNB, Asano S, Hasebe S, Nakamura Y, Hisaoka-Nakashima K, Kotake Y, Irifune M, Tsuga K, Takuma K, Morioka N, Kiguchi N, Ago Y. Prenatal exposure to valproic acid causes allodynia associated with spinal microglial activation. Neurochem Int 2022; 160:105415. [PMID: 36027995 DOI: 10.1016/j.neuint.2022.105415] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/14/2022] [Accepted: 08/19/2022] [Indexed: 11/30/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and social interaction and the presence of restricted, repetitive behaviors. Additionally, difficulties in sensory processing commonly occur in ASD. Sensory abnormalities include heightened or reduced sensitivity to pain, but the mechanism underlying sensory phenotypes in ASD remain unknown. Emerging evidence suggests that microglia play an important role in forming and refining neuronal circuitry, and thus contribute to neuronal plasticity and nociceptive signaling. In the present study, we investigated the age-dependent tactile sensitivity in an animal model of ASD induced by prenatal exposure to valproic acid (VPA) and subsequently assessed the involvement of microglia in the spinal cord in pain processing. Pregnant ICR (CD1) mice were intraperitoneally injected with either saline or VPA (500 mg/kg) on embryonic day 12.5. Male offspring of VPA-treated mothers showed mechanical allodynia at both 4 and 8 weeks of age. In the spinal cord dorsal horn in prenatally VPA-treated mice, the numbers and staining intensities of ionized calcium-binding adapter molecule 1-positive cells were increased and the cell bodies became enlarged, indicating microglial activation. Treatment with PLX3397, a colony-stimulating factor 1 receptor inhibitor, for 10 days resulted in a decreased number of spinal microglia and attenuated mechanical allodynia in adult mice prenatally exposed to VPA. Additionally, intrathecal injection of Mac-1-saporin, a saporin-conjugated anti-CD11b antibody to deplete microglia, abolished mechanical allodynia. These findings suggest that prenatal VPA treatment causes allodynia and that spinal microglia contribute to the increased nociceptive responses.
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Affiliation(s)
- Eiji Imado
- Department of Cellular and Molecular Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; Department of Dental Anesthesiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan
| | - Samnang Sun
- School of Dentistry, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; Faculty of Odonto-Stomatology, University of Health Sciences, #73, Monivong Blvd., Sangkat Sras Chak, Khan Daun Penh, Phnom Penh, 12201, Cambodia
| | - Abrar Rizal Abawa
- School of Dentistry, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; Faculty of Dental Medicine, Universitas Airlangga, Jl. Mayjen Prof. Dr. Moestopo No. 47, Surabaya, East Java, 60132, Indonesia
| | - Takeru Tahara
- Department of Neurochemistry and Environmental Health Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Takahiro Kochi
- Department of Dental Anesthesiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan
| | - Tran Ngoc Bao Huynh
- School of Dentistry, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; Faculty of Odonto-Stomatology, Hong Bang International University, 215 Dien Bien Phu Street, Ward 15, Binh Thanh District, Ho Chi Minh City, Viet Nam
| | - Satoshi Asano
- Department of Cellular and Molecular Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; School of Dentistry, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan
| | - Shigeru Hasebe
- Department of Pharmacology, Graduate School of Dentistry, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yoki Nakamura
- Department of Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan
| | - Kazue Hisaoka-Nakashima
- Department of Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan
| | - Yaichiro Kotake
- Department of Neurochemistry and Environmental Health Sciences, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Masahiro Irifune
- Department of Dental Anesthesiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; School of Dentistry, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan
| | - Kazuhiro Tsuga
- School of Dentistry, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; Department of Advanced Prosthodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan
| | - Kazuhiro Takuma
- Department of Pharmacology, Graduate School of Dentistry, Osaka University, Suita, Osaka, 565-0871, Japan; Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, 565-0871, Japan
| | - Norimitsu Morioka
- Department of Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan
| | - Norikazu Kiguchi
- Department of Physiological Sciences, School of Pharmaceutical Sciences, Wakayama Medical University, Wakayama, Wakayama, 640-8156, Japan
| | - Yukio Ago
- Department of Cellular and Molecular Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; School of Dentistry, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Hiroshima, 734-8553, Japan; Laboratory of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka, 565-0871, Japan; Global Center for Medical Engineering and Informatics, Osaka University, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.
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Chemogenetic and Optogenetic Manipulations of Microglia in Chronic Pain. Neurosci Bull 2022; 39:368-378. [PMID: 35976535 PMCID: PMC10043090 DOI: 10.1007/s12264-022-00937-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/03/2022] [Indexed: 10/15/2022] Open
Abstract
Chronic pain relief remains an unmet medical need. Current research points to a substantial contribution of glia-neuron interaction in its pathogenesis. Particularly, microglia play a crucial role in the development of chronic pain. To better understand the microglial contribution to chronic pain, specific regional and temporal manipulations of microglia are necessary. Recently, two new approaches have emerged that meet these demands. Chemogenetic tools allow the expression of designer receptors exclusively activated by designer drugs (DREADDs) specifically in microglia. Similarly, optogenetic tools allow for microglial manipulation via the activation of artificially expressed, light-sensitive proteins. Chemo- and optogenetic manipulations of microglia in vivo are powerful in interrogating microglial function in chronic pain. This review summarizes these emerging tools in studying the role of microglia in chronic pain and highlights their potential applications in microglia-related neurological disorders.
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Zhang K, Pan J, Yu Y. Regulation of Neural Circuitry under General Anesthesia: New Methods and Findings. Biomolecules 2022; 12:biom12070898. [PMID: 35883456 PMCID: PMC9312763 DOI: 10.3390/biom12070898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 02/01/2023] Open
Abstract
General anesthesia has been widely utilized since the 1840s, but its underlying neural circuits remain to be completely understood. Since both general anesthesia and sleep are reversible losses of consciousness, studies on the neural-circuit mechanisms affected by general anesthesia have mainly focused on the neural nuclei or the pathways known to regulate sleep. Three advanced technologies commonly used in neuroscience, in vivo calcium imaging, chemogenetics, and optogenetics, are used to record and modulate the activity of specific neurons or neural circuits in the brain areas of interest. Recently, they have successfully been used to study the neural nuclei and pathways of general anesthesia. This article reviews these three techniques and their applications in the brain nuclei or pathways affected by general anesthesia, to serve as a reference for further and more accurate exploration of other neural circuits under general anesthesia and to contribute to other research fields in the future.
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Affiliation(s)
- Kai Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; (K.Z.); (J.P.)
- Tianjin Institute of Anesthesiology, Tianjin 300052, China
| | - Jiacheng Pan
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; (K.Z.); (J.P.)
- Tianjin Institute of Anesthesiology, Tianjin 300052, China
| | - Yonghao Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; (K.Z.); (J.P.)
- Tianjin Institute of Anesthesiology, Tianjin 300052, China
- Correspondence:
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15
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Bolton JL, Short AK, Othy S, Kooiker CL, Shao M, Gunn BG, Beck J, Bai X, Law SM, Savage JC, Lambert JJ, Belelli D, Tremblay MÈ, Cahalan MD, Baram TZ. Early stress-induced impaired microglial pruning of excitatory synapses on immature CRH-expressing neurons provokes aberrant adult stress responses. Cell Rep 2022; 38:110600. [PMID: 35354026 PMCID: PMC9014810 DOI: 10.1016/j.celrep.2022.110600] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 02/10/2022] [Accepted: 03/08/2022] [Indexed: 12/12/2022] Open
Abstract
Several mental illnesses, characterized by aberrant stress reactivity, often arise after early-life adversity (ELA). However, it is unclear how ELA affects stress-related brain circuit maturation, provoking these enduring vulnerabilities. We find that ELA increases functional excitatory synapses onto stress-sensitive hypothalamic corticotropin-releasing hormone (CRH)-expressing neurons, resulting from disrupted developmental synapse pruning by adjacent microglia. Microglial process dynamics and synaptic element engulfment were attenuated in ELA mice, associated with deficient signaling of the microglial phagocytic receptor MerTK. Accordingly, selective chronic chemogenetic activation of ELA microglia increased microglial process dynamics and reduced excitatory synapse density to control levels. Notably, selective early-life activation of ELA microglia normalized adult acute and chronic stress responses, including stress-induced hormone secretion and behavioral threat responses, as well as chronic adrenal hypertrophy of ELA mice. Thus, microglial actions during development are powerful contributors to mechanisms by which ELA sculpts the connectivity of stress-regulating neurons, promoting vulnerability to stress and stress-related mental illnesses. Early-life adversity (ELA) promotes lifelong aberrant stress responses and vulnerability to mental illnesses. Bolton et al. identify poor dynamics and hypothalamic CRH neurons’ excitatory synapse pruning of ELA microglia, implicating microglial MerTK. Chronic chemogenetic activation of ELA microglia normalized process dynamics, synapse density, and adult hormonal and behavioral stress responses.
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Affiliation(s)
- Jessica L Bolton
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA.
| | - Annabel K Short
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Shivashankar Othy
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
| | - Cassandra L Kooiker
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Manlin Shao
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Benjamin G Gunn
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA; Division of Neuroscience, Medical Research Institute, Dundee University, Ninewells Hospital and Medical School, Dundee, UK
| | - Jaclyn Beck
- Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Xinglong Bai
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Stephanie M Law
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Julie C Savage
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada; Axe Neurosciences, Centre de recherche du CHU de Québec, Québec City, QC, Canada
| | - Jeremy J Lambert
- Division of Neuroscience, Medical Research Institute, Dundee University, Ninewells Hospital and Medical School, Dundee, UK
| | - Delia Belelli
- Division of Neuroscience, Medical Research Institute, Dundee University, Ninewells Hospital and Medical School, Dundee, UK
| | - Marie-Ève Tremblay
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada; Axe Neurosciences, Centre de recherche du CHU de Québec, Québec City, QC, Canada
| | - Michael D Cahalan
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
| | - Tallie Z Baram
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA; Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA.
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Smith CJ. Emerging roles for microglia and microbiota in the development of social circuits. Brain Behav Immun Health 2021; 16:100296. [PMID: 34589789 PMCID: PMC8474572 DOI: 10.1016/j.bbih.2021.100296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/28/2021] [Accepted: 07/12/2021] [Indexed: 01/03/2023] Open
Abstract
Social withdrawal is a core component of the behavioral response to infection. This fact points to a deep evolutionary and biologic relationship between the immune system and the social brain. Indeed, a large body of literature supports such an intimate connection. In particular, immune activation during the perinatal period has been shown to have long-lasting consequences for social behavior, but the neuroimmune mechanisms by which this occurs are only partially understood. Microglia, the resident immune cells of the brain, influence the formation of neural circuits by phagocytosing synaptic and cellular elements, as well as by releasing chemokines and cytokines. Intriguingly, microbiota, especially those that reside within the gut, may also influence brain development via the release of metabolites that travel to the brain, by influencing vagal nerve signaling, or by modulating the host immune system. Here, I will review the work suggesting important roles for microglia and microbiota in social circuit formation during development. I will then highlight avenues for future work in this area, as well as technological advances that extend our capacity to ask mechanistic questions about the relationships between microglia, microbiota, and the social brain.
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Affiliation(s)
- Caroline J Smith
- Department of Psychology and Neuroscience, Duke University, Durham, NC, 27710, USA
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