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Tripathi A, Bartosh A, Mata J, Jacks C, Madeshiya AK, Hussein U, Hong LE, Zhao Z, Pillai A. Microglial type I interferon signaling mediates chronic stress-induced synapse loss and social behavior deficits. Mol Psychiatry 2024:10.1038/s41380-024-02675-6. [PMID: 39095477 DOI: 10.1038/s41380-024-02675-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 07/11/2024] [Accepted: 07/15/2024] [Indexed: 08/04/2024]
Abstract
Inflammation and synapse loss have been associated with deficits in social behavior and are involved in pathophysiology of many neuropsychiatric disorders. Synapse loss, characterized by reduction in dendritic spines can significantly disrupt synaptic connectivity and neural circuitry underlying social behavior. Chronic stress is known to induce loss of spines and dendrites in the prefrontal cortex (PFC), a brain region implicated in social behavior. However, the underlying mechanisms are not well understood. In the present study, we investigated the role of type I Interferon (IFN-I) signaling in chronic unpredictable stress (CUS)-induced synapse loss and behavior deficits in mice. We found increased expression of type I IFN receptor (IFNAR) in microglia following CUS. Conditional knockout of microglial IFNAR in adult mice rescued CUS-induced social behavior deficits and synapse loss. Bulk RNA sequencing data show that microglial IFNAR deletion attenuated CUS-mediated changes in the expression of genes such as Keratin 20 (Krt20), Claudin-5 (Cldn5) and Nuclear Receptor Subfamily 4 Group A Member 1 (Nr4a1) in the PFC. Cldn5 and Nr4a1 are known for their roles in synaptic plasticity. Krt20 is an intermediate filament protein responsible for the structural integrity of epithelial cells. The reduction in Krt20 following CUS presents a novel insight into the potential contribution of cytokeratin in stress-induced alterations in neuroplasticity. Overall, these results suggest that microglial IFNAR plays a critical role in regulating synaptic plasticity and social behavior deficits associated with chronic stress conditions.
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Affiliation(s)
- Ashutosh Tripathi
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Alona Bartosh
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Jocelyn Mata
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Chale Jacks
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Amit Kumar Madeshiya
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Usama Hussein
- Center for Precision Health, McWilliams School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Department of Lymphoma & Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - L Elliot Hong
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Zhongming Zhao
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
- Center for Precision Health, McWilliams School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Anilkumar Pillai
- Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA.
- Charlie Norwood VA Medical Center, Augusta, GA, USA.
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2
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Li CF, Zhang QP, Cheng J, Xu GH, Zhu JX, Yi LT. Role of ginsenoside Rb1 in attenuating depression-like symptoms through astrocytic and microglial complement C3 pathway. Metab Brain Dis 2024; 39:1039-1050. [PMID: 39034364 DOI: 10.1007/s11011-024-01392-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 07/09/2024] [Indexed: 07/23/2024]
Abstract
Ginsenoside Rb1, known as gypenoside III, exerts antidepressant-like effects in previous studies. It has also been indicated that ginsenoside Rb1 regulated neuroinflammation via inhibiting NF-κB signaling. According to the evidence that astrocytes can regulate microglia and neuroinflammation by secreting complement C3, the present study aimed to demonstrate the molecular mechanisms underlying ginsenoside Rb1-induced antidepressant-like effects from the astrocytic and microglial complement C3 pathway. The complement C3 mediated mechanism of ginsenoside Rb1 was investigated in mice exposed to chronic restraint stress (CRS). The results showed that ginsenoside Rb1 reversed the depressive-like behaviors in CRS. Treatment with ginsenoside Rb1 reduced both the number of astrocytes and microglia. In addition, ginsenoside Rb1 suppressed TLR4/NF-κB/C3 signaling in the astrocytes of the hippocampus. Furthermore, ginsenoside Rb1 attenuated the contents of synaptic protein including synaptophysin and PSD95 in microglia, suggesting the inhibition of microglia-mediated synaptic elimination caused by CRS. Importantly, ginsenoside Rb1 also maintained the dendritic spines in mice. In conclusion, our results demonstrate that ginsenoside Rb1 produces the antidepressant-like effects by inhibiting astrocyte TLR4/NF-κB/C3 signaling to covert microglia from a pro-inflammatory phenotype (amoeboid) towards an anti-inflammatory phenotype (ramified), which inhibit the synaptic pruning in the hippocampus.
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Affiliation(s)
- Cheng-Fu Li
- Xiamen Hospital of Traditional Chinese Medicine, Xiamen, 361009, Fujian province, PR China.
| | - Qiu-Ping Zhang
- Xiamen Hospital of Traditional Chinese Medicine, Xiamen, 361009, Fujian province, PR China
| | - Jie Cheng
- Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, PR China
| | - Guang-Hui Xu
- Xiamen Medicine Research Institute, Xiamen, 361008, Fujian province, PR China
| | - Ji-Xiao Zhu
- Research Center of Natural Resources of Chinese Medicinal Materials and Ethnic Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, Jiangxi province, PR China
| | - Li-Tao Yi
- Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University, Xiamen, 361021, Fujian province, PR China
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3
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Patel RR, Gandhi P, Spencer K, Salem NA, Erikson CM, Borgonetti V, Vlkolinsky R, Rodriguez L, Nadav T, Bajo M, Roberts AJ, Dayne Mayfield R, Roberto M. Functional and morphological adaptation of medial prefrontal corticotropin releasing factor receptor 1-expressing neurons in male mice following chronic ethanol exposure. Neurobiol Stress 2024; 31:100657. [PMID: 38983690 PMCID: PMC11231756 DOI: 10.1016/j.ynstr.2024.100657] [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: 03/27/2024] [Revised: 06/13/2024] [Accepted: 06/15/2024] [Indexed: 07/11/2024] Open
Abstract
Chronic ethanol dependence and withdrawal activate corticotropin releasing factor (CRF)-containing GABAergic neurons in the medial prefrontal cortex (mPFC), which tightly regulate glutamatergic pyramidal neurons. Using male CRF1:GFP reporter mice, we recently reported that CRF1-expressing (mPFCCRF1+) neurons predominantly comprise mPFC prelimbic layer 2/3 pyramidal neurons, undergo profound adaptations following chronic ethanol exposure, and regulate anxiety and conditioned rewarding effects of ethanol. To explore the effects of acute and chronic ethanol exposure on glutamate transmission, the impact of chronic alcohol on spine density and morphology, as well as persistent changes in dendritic-related gene expression, we employed whole-cell patch-clamp electrophysiology, diOlistic labeling for dendritic spine analysis, and dendritic gene expression analysis to further characterize mPFCCRF1+ and mPFCCRF1- prelimbic layer 2/3 pyramidal neurons. We found increased glutamate release in mPFCCRF1+ neurons with ethanol dependence, which recovered following withdrawal. In contrast, we did not observe significant changes in glutamate transmission in neighboring mPFCCRF1- neurons. Acute application of 44 mM ethanol significantly reduced glutamate release onto mPFCCRF1+ neurons, which was observed across all treatment groups. However, this sensitivity to acute ethanol was only evident in mPFCCRF1- neurons during withdrawal. In line with alterations in glutamate transmission, we observed a decrease in total spine density in mPFCCRF1+ neurons during dependence, which recovered following withdrawal, while again no changes were observed in mPFCCRF- neurons. Given the observed decreases in mPFCCRF1+ stubby spines during withdrawal, we then identified persistent changes at the dendritic gene expression level in mPFCCRF1+ neurons following withdrawal that may underlie these structural adaptations. Together, these findings highlight the varying responses of mPFCCRF1+ and mPFCCRF1- cell-types to acute and chronic ethanol exposure, as well as withdrawal, revealing specific functional, morphological, and molecular adaptations that may underlie vulnerability to ethanol and the lasting effects of ethanol dependence.
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Affiliation(s)
- Reesha R Patel
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Pauravi Gandhi
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Kathryn Spencer
- Core Microscopy Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Nihal A Salem
- Department of Neuroscience, The University of Texas at Austin, Austin, TX, 78712, USA
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Chloe M Erikson
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Vittoria Borgonetti
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Roman Vlkolinsky
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Larry Rodriguez
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Tali Nadav
- Animal Models Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Michal Bajo
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Amanda J Roberts
- Animal Models Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - R Dayne Mayfield
- Department of Neuroscience, The University of Texas at Austin, Austin, TX, 78712, USA
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Marisa Roberto
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
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Jiang Y, Xu L, Cao Y, Meng F, Jiang S, Yang M, Zheng Z, Zhang Y, Yang L, Wang M, Sun G, Liu J, Li C, Cui M. Effects of Interleukin-19 overexpression in the medial prefrontal cortex on anxiety-related behaviors, BDNF expression and p38/JNK/ERK pathways. Brain Res Bull 2024; 212:110952. [PMID: 38636611 DOI: 10.1016/j.brainresbull.2024.110952] [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: 01/05/2024] [Revised: 03/27/2024] [Accepted: 04/14/2024] [Indexed: 04/20/2024]
Abstract
Anxiety is a prevalent mental illness known for its high incidence, comorbidity, and tendency to recur, posing significant societal and individual burdens. Studies have highlighted Interleukin-19 (IL-19) as having potential relevance in neuropsychiatric disorders. Our previous research revealed that IL-19 overexpression in colonies exacerbated anxiety-related behaviors induced by dextran sodium sulfate/stress. However, the precise role and molecular mechanisms of IL-19 in anxiety regulation remain uncertain. In this study, we initiated an acute restraint stress (ARS)-induced anxious mouse model and identified heightened expression of IL-19 and IL-20Rα in the medial prefrontal cortex (mPFC) of ARS mice. Notably, IL-19 and IL-20Rα were predominantly present in the excitatory pyramidal neurons of the mPFC under both basal and ARS conditions. Utilizing the adeno-associated virus (AAV) strategy, we demonstrated that IL-19 overexpression in the mPFC induced anxiety-related behaviors and elevated stress susceptibility. Additionally, we observed decreased protein levels of brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD95) in the mPFC of IL-19 overexpression mice, accompanied by reduced phosphorylation of in the p38, JNK, and Erk signaling pathways. These findings emphasize the role of IL-19 in modulating anxiety-related behaviors within the mPFC and suggest its potential as a pathological gene and therapeutic target for anxiety.
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Affiliation(s)
- Yuting Jiang
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Lihong Xu
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Yifan Cao
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Fantao Meng
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Shujun Jiang
- Department of Physiology, Binzhou Medical University, Shandong, China
| | - Mengyu Yang
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Ziteng Zheng
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Yi Zhang
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Lu Yang
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Meiqin Wang
- Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China; Department of Physiology, Binzhou Medical University, Shandong, China
| | - Guizhi Sun
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Jing Liu
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China.
| | - Chen Li
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China.
| | - Minghu Cui
- Department of Psychology, Binzhou Medical University Hospital, Binzhou, Shandong, China; Medical Research Center, Binzhou Medical University Hospital, Binzhou, Shandong, China.
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5
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Crockett A, Fuhrmann M, Garaschuk O, Davalos D. Progress in Structural and Functional In Vivo Imaging of Microglia and Their Application in Health and Disease. ADVANCES IN NEUROBIOLOGY 2024; 37:65-80. [PMID: 39207687 DOI: 10.1007/978-3-031-55529-9_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The first line of defense for the central nervous system (CNS) against injury or disease is provided by microglia. Microglia were long believed to stay in a dormant/resting state, reacting only to injury or disease. This view changed dramatically with the development of modern imaging techniques that allowed the study of microglial behavior in the intact brain over time, to reveal the dynamic nature of their responses. Over the past two decades, in vivo imaging using multiphoton microscopy has revealed numerous new functions of microglia in the developing, adult, aged, injured, and diseased CNS. As the most dynamic cells in the brain, microglia continuously contact all structures and cell types, such as glial and vascular cells, neuronal cell bodies, axons, dendrites, and dendritic spines, and are believed to play a central role in sculpting neuronal networks throughout life. Following trauma, or in neurodegenerative or neuroinflammatory diseases, microglial responses range from protective to harmful, underscoring the need to better understand their diverse roles and states in different pathological conditions. In this chapter, we introduce multiphoton microscopy and discuss recent advances in structural and functional imaging technologies that have expanded our toolbox to study microglial states and behaviors in new ways and depths. We also discuss relevant mouse models available for in vivo imaging studies of microglia and review how such studies are constantly refining our understanding of the multifaceted role of microglia in the healthy and diseased CNS.
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Affiliation(s)
- Alexis Crockett
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Olga Garaschuk
- Institute of Physiology, Department of Neurophysiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Dimitrios Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, USA.
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Wegener AJ, Hyer MM, Targett I, Kloster A, Shaw GA, Rodriguez AMM, Dyer SK, Neigh GN. Behavior, synaptic mitochondria, and microglia are differentially impacted by chronic adolescent stress and repeated endotoxin exposure in male and female rats. Stress 2024; 27:2299971. [PMID: 38179979 PMCID: PMC11064104 DOI: 10.1080/10253890.2023.2299971] [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: 09/05/2023] [Accepted: 12/16/2023] [Indexed: 01/06/2024] Open
Abstract
Early life adversity and chronic inflammation have both been associated with cognitive impairment and neural compromise. In this study, we investigated the interactions between a history of chronic adolescent stress (CAS) and repeated endotoxin exposure on behavior, synaptic mitochondria, and microglia in adult male and female Wistar rats. Adult rats from chronic stress and control conditions were exposed to either repeated endotoxin (lipopolysaccharide; LPS) or saline injections every 3 days for 9 weeks. In both sexes, repeated LPS, regardless of stress history, impaired working memory in the Y maze. Regarding spatial memory, LPS impaired function for females; whereas, CAS altered function in males. Although males had an increase in anxiety-like behavior shortly after CAS, there were no long-term effects on anxiety-like behavior or social interaction observed in males or females. Stress did not alter synaptic mitochondrial function in either sex. Repeated LPS altered synaptic mitochondrial function such that ATP production was increased in females only. There were no observed increases in IBA-1 positive cells within the hippocampus for either sex. However, LPS and CAS altered microglia morphology in females. Impact of repeated LPS was evident at the terminal endpoint with increased spleen weight in both sexes and decreased adrenal weight in males only. Circulating cytokines were not impacted by repeated LPS at the terminal endpoint, but evidence of CAS effects on cytokines in females were evident. These data suggest a long-term impact of chronic stress and an impact of repeated endotoxin challenge in adulthood; however, not all physiological and behavioral metrics examined were impacted by the paradigm employed in this study and the two environmental challenges rarely interacted.
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Affiliation(s)
- A J Wegener
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA
| | - M M Hyer
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA
| | - I Targett
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA
| | - A Kloster
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA
| | - G A Shaw
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA
| | - A M M Rodriguez
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA
| | - S K Dyer
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA
| | - G N Neigh
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, USA
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Bollinger JL, Dadosky DT, Flurer JK, Rainer IL, Woodburn SC, Wohleb ES. Microglial P2Y12 mediates chronic stress-induced synapse loss in the prefrontal cortex and associated behavioral consequences. Neuropsychopharmacology 2023; 48:1347-1357. [PMID: 36517583 PMCID: PMC10354016 DOI: 10.1038/s41386-022-01519-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 12/15/2022]
Abstract
Chronic unpredictable stress (CUS) drives microglia-mediated neuronal remodeling and synapse loss in the prefrontal cortex (PFC), contributing to deficits in cognition and behavior. However, it remains unclear what mechanisms guide microglia-neuron interactions in stress. Evidence indicates that neuronal activity-dependent purinergic signaling directs microglial processes and synaptic engagement via P2Y12, a purinergic receptor exclusively expressed by microglia in the brain. Stress alters excitatory neurotransmission in the PFC, thus we aimed to determine if P2Y12 signaling promotes functional changes in microglia in chronic stress. Here we used genetic ablation of P2Y12 (P2ry12-/-) or pharmacological blockade (clopidogrel, ticagrelor) to examine the role of purinergic signaling in stress-induced microglia-neuron interaction. Multiple behavioral, physiological, and cytometric endpoints were analyzed. Deletion of P2Y12 led to a number of fundamental alterations in the PFC, including the heightened microglial number and increased dendritic spine density. Flow cytometry revealed that microglia in P2ry12-/- mice had shifts in surface levels of CX3CR1, CSF1R, and CD11b, suggesting changes in synaptic engagement and phagocytosis in the PFC. In line with this, pharmacological blockade of P2Y12 prevented CUS-induced increases in the proportion of microglia with neuronal inclusions, limited dendritic spine loss in the PFC, and attenuated alterations in stress coping behavior and working memory function. Overall, these findings indicate that microglial P2Y12 is a critical mediator of stress-induced synapse loss in the PFC and subsequent behavioral deficits.
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Affiliation(s)
- Justin L Bollinger
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - David T Dadosky
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - James K Flurer
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Ivanka L Rainer
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Samuel C Woodburn
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Eric S Wohleb
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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Sequeira MK, Bolton JL. Stressed Microglia: Neuroendocrine-Neuroimmune Interactions in the Stress Response. Endocrinology 2023; 164:bqad088. [PMID: 37279575 DOI: 10.1210/endocr/bqad088] [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: 03/20/2023] [Revised: 05/22/2023] [Accepted: 06/02/2023] [Indexed: 06/08/2023]
Abstract
Stressful life experiences are associated with the development of neuropsychiatric disorders like depression. Emerging evidence indicates that microglia, the specialized resident macrophages of the brain, may be a key mediator of the relationship between psychosocial stressor exposure and adaptive or maladaptive responses at the level of synaptic, circuit, and neuroimmune alterations. Here, we review current literature regarding how psychosocial stressor exposure changes microglial structure and function, thereby altering behavioral and brain outcomes, with a particular focus on age- and sex-dependent effects. We argue that additional emphasis should be placed in future research on investigating sex differences and the impacts of stressor exposure during sensitive periods of development, as well as going beyond traditional morphological measurements to interrogate microglial function. The bidirectional relationship between microglia and the stress response, particularly the role of microglia in the neuroendocrine control of stress-related circuits, is also an important area for future investigation. Finally, we discuss emerging themes and future directions that point to the possibility of the development of novel therapeutics for stress-related neuropsychiatric disorders.
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Affiliation(s)
| | - Jessica L Bolton
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
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Fan FC, Du Y, Zheng WH, Loh YP, Cheng Y. Carboxypeptidase E conditional knockout mice exhibit learning and memory deficits and neurodegeneration. Transl Psychiatry 2023; 13:135. [PMID: 37100779 PMCID: PMC10133319 DOI: 10.1038/s41398-023-02429-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/03/2023] [Accepted: 04/06/2023] [Indexed: 04/28/2023] Open
Abstract
Carboxypeptidase E (CPE) is a multifunctional protein with many nonenzymatic functions in various systems. Previous studies using CPE knock-out mice have shown that CPE has neuroprotective effects against stress and is involved in learning and memory. However, the functions of CPE in neurons are still largely unknown. Here we used a Camk2a-Cre system to conditionally knockout CPE in neurons. The wild-type, CPEflox/-, and CPEflox/flox mice were weaned, ear-tagged, and tail clipped for genotyping at 3 weeks old, and they underwent open field, object recognition, Y-maze, and fear conditioning tests at 8 weeks old. The CPEflox/flox mice had normal body weight and glucose metabolism. The behavioral tests showed that CPEflox/flox mice had impaired learning and memory compared with wild-type and CPEflox/- mice. Surprisingly, the subiculum (Sub) region of CPEflox/flox mice was completely degenerated, unlike the CPE full knockout mice, which exhibit CA3 region neurodegeneration. In addition, doublecortin immunostaining suggested that neurogenesis in the dentate gyrus of the hippocampus was significantly reduced in CPEflox/flox mice. Interestingly, TrkB phosphorylation in the hippocampus was downregulated in CPEflox/flox mice, but brain-derived neurotrophic factor levels were not. In both the hippocampus and dorsal medial prefrontal cortex, we observed reduced MAP2 and GFAP expression in CPEflox/flox mice. Taken together, the results of this study demonstrate that specific neuronal CPE knockout leads to central nervous system dysfunction in mice, including learning and memory deficits, hippocampal Sub degeneration and impaired neurogenesis.
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Affiliation(s)
- Fang-Cheng Fan
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, School of Pharmacy, Minzu University of China, Beijing, China
| | - Yang Du
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, School of Pharmacy, Minzu University of China, Beijing, China
| | - Wen-Hui Zheng
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, School of Pharmacy, Minzu University of China, Beijing, China
| | - Y Peng Loh
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Yong Cheng
- Key Laboratory of Ethnomedicine of Ministry of Education, Center on Translational Neuroscience, School of Pharmacy, Minzu University of China, Beijing, China.
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China.
- Institute of National Security, Minzu University of China, Beijing, China.
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10
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Cangalaya C, Wegmann S, Sun W, Diez L, Gottfried A, Richter K, Stoyanov S, Pakan J, Fischer KD, Dityatev A. Real-time mechanisms of exacerbated synaptic remodeling by microglia in acute models of systemic inflammation and tauopathy. Brain Behav Immun 2023; 110:245-259. [PMID: 36906076 DOI: 10.1016/j.bbi.2023.02.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 03/13/2023] Open
Abstract
Remodeling of synapses by microglia is essential for synaptic plasticity in the brain. However, during neuroinflammation and neurodegenerative diseases, microglia can induce excessive synaptic loss, although the precise underlying mechanisms are unknown. To directly observe microglia-synapse interactions under inflammatory conditions, we performed in vivo two-photon time-lapse imaging of microglia-synapse interactions after bacterial lipopolysaccharide administration to model systemic inflammation, or after inoculation of Alzheimer's disease (AD) brain extracts to model disease-associated neuroinflammatory microglial response. Both treatments prolonged microglia-neuron contacts, decreased basal surveillance of synapses and promoted synaptic remodeling in response to synaptic stress induced by focal single-synapse photodamage. Spine elimination correlated with the expression of microglial complement system/phagocytic proteins and the occurrence of synaptic filopodia. Microglia were observed contacting spines, then stretching and phagocytosing spine head filopodia. Thus, in response to inflammatory stimuli microglia exacerbated spine remodeling through prolonged microglial contact and elimination of spines 'tagged' by synaptic filopodia.
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Affiliation(s)
- Carla Cangalaya
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany; Institut für Biochemie und Zellbiologie, Otto-von-Guericke-University, Medical Faculty, Magdeburg, Germany; ESF International Graduate School on Analysis, Imaging and Modelling of Neuronal and Inflammatory Processes, Magdeburg, Germany
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Weilun Sun
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Lisa Diez
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Anna Gottfried
- Institut für Biochemie und Zellbiologie, Otto-von-Guericke-University, Medical Faculty, Magdeburg, Germany
| | - Karin Richter
- Institut für Biochemie und Zellbiologie, Otto-von-Guericke-University, Medical Faculty, Magdeburg, Germany
| | - Stoyan Stoyanov
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Janelle Pakan
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany; Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Klaus-Dieter Fischer
- Institut für Biochemie und Zellbiologie, Otto-von-Guericke-University, Medical Faculty, Magdeburg, Germany
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany; Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany.
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11
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Sun J, Jia K, Sun M, Zhang X, Chen J, Zhu G, Li C, Lian B, Du Z, Sun H, Sun L. The GluA1-Related BDNF Pathway Is Involved in PTSD-Induced Cognitive Flexibility Deficit in Attentional Set-Shifting Tasks of Rats. J Clin Med 2022; 11:jcm11226824. [PMID: 36431303 PMCID: PMC9694369 DOI: 10.3390/jcm11226824] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/07/2022] [Accepted: 11/15/2022] [Indexed: 11/22/2022] Open
Abstract
Background: Post-Traumatic Stress Disorder (PTSD) is a severe psychological disorder characterized by intrusive thoughts, heightened arousal, avoidance, and flashbacks. Cognitive flexibility dysfunction has been linked with the emergence of PTSD, including response inhibition deficits and impaired attentional switching, which results in difficulties for PTSD patients when disengaging attention from trauma-related stimuli. However, the molecular mechanisms of cognitive flexibility deficits remain unclear. Methods: The animals were exposed to a single prolonged stress and electric foot shock (SPS&S) procedure to induce PTSD-like features. Once the model was established, the changes in cognitive flexibility were assessed using an attentional set-shifting task (ASST) in order to investigate the effects of traumatic stress on cognitive flexibility. Additionally, the molecular alterations of certain proteins (AMPA Receptor 1 (GluA1), brain-derived neurotrophic factor (BDNF), and Postsynaptic density protein 95 (PSD95) in the medial prefrontal cortex (mPFC) were measured using Western blot and immunofluorescence. Results: The SPS&S model exhibited PTSD-like behaviors and induced reversal learning and set-shifting ability deficit in the ASST. These behavioral changes are accompanied by decreased GluA1, BDNF, and PSD95 protein expression in the mPFC. Further analysis showed a correlative relationship between the behavioral and molecular alterations. Conclusions: The SPS&S model induced cognitive flexibility deficits, and the potential underlying mechanism could be mediated by GluA1-related BDNF signaling in the mPFC.
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Affiliation(s)
- Jiaming Sun
- School of Psychology, Weifang Medical University, 7166# Baotong West Street, Weifang 261053, China
| | - Keli Jia
- School of Psychology, Weifang Medical University, 7166# Baotong West Street, Weifang 261053, China
| | - Mingtao Sun
- School of Psychology, Weifang Medical University, 7166# Baotong West Street, Weifang 261053, China
| | - Xianqiang Zhang
- National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital/Institute of Mental Health and the Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, China
| | - Jinhong Chen
- College of Extended Education, Weifang Medical University, 7166# Baotong West Street, Weifang 261053, China
| | - Guohui Zhu
- Mental Health Centre of Weifang City, Weifang 261071, China
| | - Changjiang Li
- School of Psychology, Weifang Medical University, 7166# Baotong West Street, Weifang 261053, China
| | - Bo Lian
- Department of Bioscience and Technology, Weifang Medical University, 7166# Baotong West Street, Weifang 261053, China
| | - Zhongde Du
- Cerebral Center, Sunshine Union Hospital, 9000# Yingqian Street, Weifang 261205, China
| | - Hongwei Sun
- School of Psychology, Weifang Medical University, 7166# Baotong West Street, Weifang 261053, China
- Correspondence: (H.S.); (L.S.)
| | - Lin Sun
- School of Psychology, Weifang Medical University, 7166# Baotong West Street, Weifang 261053, China
- Correspondence: (H.S.); (L.S.)
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12
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High-Fat Diet Consumption in Adolescence Induces Emotional Behavior Alterations and Hippocampal Neurogenesis Deficits Accompanied by Excessive Microglial Activation. Int J Mol Sci 2022; 23:ijms23158316. [PMID: 35955450 PMCID: PMC9368636 DOI: 10.3390/ijms23158316] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 07/24/2022] [Accepted: 07/26/2022] [Indexed: 11/17/2022] Open
Abstract
Adolescence is a developmental epoch characterized by massive neural circuit remodeling; thus, the brain is particularly vulnerable to environmental influences during this period. Excessive high-fat diet (HFD) consumption, which is very common among adolescents, has long been recognized as a potent risk factor for multiple mood disorders, including depression and anxiety. However, the precise mechanisms underlying the influences of HFD consumption in adolescence on emotional health are far from clear. In the present study, C57BL/6 mice were fed a control diet (CD) or HFD for about 4 weeks from postnatal day (P) 28 to P60, spanning most of the adolescence period, and then subjected to behavioral assessments and histological examinations. HFD mice exhibited elevated levels of depression and anxiety, decreased hippocampal neurogenesis, and excessive microglial activation in the ventral hippocampus. Furthermore, in HFD-fed mice, microglia showed increased DCX+ inclusions, suggesting aberrant microglial engulfment of newborn neurons in HFD-fed adolescents. To our knowledge, this is the first observation suggesting that the negative effects of HFD consumption in adolescence on emotion and neuroplasticity may be attributed at least in part to aberrant microglial engulfment of nascent neurons, extending our understanding of the mechanism underlying HFD-related affective disorders in young people.
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13
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Chen M, Qi J, Poo M, Yang Y. Stability and dynamics of dendritic spines in macaque prefrontal cortex. Natl Sci Rev 2022; 9:nwac125. [PMID: 36196248 PMCID: PMC9521340 DOI: 10.1093/nsr/nwac125] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/08/2022] [Accepted: 06/15/2022] [Indexed: 11/16/2022] Open
Abstract
Formation and elimination of synapses reflect structural plasticity of neuronal connectivity. Here we performed high-resolution two-photon imaging of dendritic spines in the prefrontal cortex of four macaque monkeys and found that spines were in general highly stable, with low percentages undergoing synaptic turnover. By observing the same spines at weekly intervals, we found that newly formed spines were more susceptible to elimination, with only 40% persisting over a period of months. Analyses of spatial distribution of large numbers of spines revealed that spine distribution was neither uniform nor random, favoring inter-spine distances of 2–4 μm. Furthermore, spine formation and elimination occurred more often in low- and high-density dendritic segments, respectively, and preferentially within a hot zone of ∼4 μm from existing spines. Our results demonstrate long-term stability and spatially regulated spine dynamics in the macaque cortex and provide a structural basis for understanding neural circuit plasticity in the primate brain.
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14
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Zhang MM, Huo GM, Cheng J, Zhang QP, Li NZ, Guo MX, Liu Q, Xu GH, Zhu JX, Li CF, Zhou F, Yi LT. Gypenoside XVII, an Active Ingredient from Gynostemma Pentaphyllum, Inhibits C3aR-Associated Synaptic Pruning in Stressed Mice. Nutrients 2022; 14:nu14122418. [PMID: 35745148 PMCID: PMC9228113 DOI: 10.3390/nu14122418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/05/2022] [Accepted: 06/07/2022] [Indexed: 12/05/2022] Open
Abstract
Gynostemma pentaphyllum is a herbal medicine widely used in Asian countries, and its saponin extracts have been shown to possess potent anti-inflammatory effects. Gypenoside XVII, an active ingredient isolated from Gynostemma pentaphyllum, has been found to alleviate the inflammation induced by LPS in the BV2 microglia, according to our preliminary study. This study aims to evaluate whether Gypenoside XVII could attenuate depression-like symptoms in vivo and tries to demonstrate the involvement of the complement regulation in its antidepressant-like effect. The results showed that Gypenoside XVII significantly attenuated depression-like behaviors in the forced swimming test, tail suspension test and sucrose preference test. It also alleviated the acute stress-induced hyperactivity of serum corticosterone levels. Additionally, Gypenoside XVII significantly inhibited the activation of microglia and the expression of C3 in mice exposed to chronic unpredictable mild stress (CUMS). Meanwhile, the activation of C3aR/STAT3 signaling and the expression of proinflammatory cytokines was reversed by Gypenoside XVII. Moreover, CUMS induced excessive synaptic pruning by activating microglia, while Gypenoside XVII restored it in the prefrontal cortex. Our data demonstrated that Gypenoside XVII, the active ingredient of Gynostemma pentaphyllum, produced the antidepressant-like effects in mice, which was mediated by the inhibition of complement C3/C3aR/STAT3/cytokine signaling in the prefrontal cortex.
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Affiliation(s)
- Man-Man Zhang
- Department of Chemical and Pharmaceutical Engineering, Huaqiao University, Xiamen 361021, China; (M.-M.Z.); (J.C.); (Q.L.)
| | - Guo-Ming Huo
- School of Food Science, Nanjing Xiaozhuang University, Nanjing 211171, China;
| | - Jie Cheng
- Department of Chemical and Pharmaceutical Engineering, Huaqiao University, Xiamen 361021, China; (M.-M.Z.); (J.C.); (Q.L.)
| | - Qiu-Ping Zhang
- Xiamen Hospital of Traditional Chinese Medicine, Xiamen 361009, China; (Q.-P.Z.); (C.-F.L.)
| | - Na-Zhi Li
- Research Center of Natural Resources of Chinese Medicinal Materials and Ethnic Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, China; (N.-Z.L.); (M.-X.G.); (J.-X.Z.)
| | - Min-Xia Guo
- Research Center of Natural Resources of Chinese Medicinal Materials and Ethnic Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, China; (N.-Z.L.); (M.-X.G.); (J.-X.Z.)
| | - Qing Liu
- Department of Chemical and Pharmaceutical Engineering, Huaqiao University, Xiamen 361021, China; (M.-M.Z.); (J.C.); (Q.L.)
| | - Guang-Hui Xu
- Xiamen Medicine Research Institute, Xiamen 361008, China;
| | - Ji-Xiao Zhu
- Research Center of Natural Resources of Chinese Medicinal Materials and Ethnic Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, China; (N.-Z.L.); (M.-X.G.); (J.-X.Z.)
| | - Cheng-Fu Li
- Xiamen Hospital of Traditional Chinese Medicine, Xiamen 361009, China; (Q.-P.Z.); (C.-F.L.)
| | - Feng Zhou
- School of Food Science, Nanjing Xiaozhuang University, Nanjing 211171, China;
- Correspondence: (F.Z.); (L.-T.Y.)
| | - Li-Tao Yi
- Department of Chemical and Pharmaceutical Engineering, Huaqiao University, Xiamen 361021, China; (M.-M.Z.); (J.C.); (Q.L.)
- Correspondence: (F.Z.); (L.-T.Y.)
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15
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Ortinski PI, Reissner KJ, Turner J, Anderson TA, Scimemi A. Control of complex behavior by astrocytes and microglia. Neurosci Biobehav Rev 2022; 137:104651. [PMID: 35367512 DOI: 10.1016/j.neubiorev.2022.104651] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/28/2022] [Accepted: 03/21/2022] [Indexed: 02/07/2023]
Abstract
Evidence that glial cells influence behavior has been gaining a steady foothold in scientific literature. Out of the five main subtypes of glial cells in the brain, astrocytes and microglia have received an outsized share of attention with regard to shaping a wide spectrum of behavioral phenomena and there is growing appreciation that the signals intrinsic to these cells as well as their interactions with surrounding neurons reflect behavioral history in a brain region-specific manner. Considerable regional diversity of glial cell phenotypes is beginning to be recognized and may contribute to behavioral outcomes arising from circuit-specific computations within and across discrete brain nuclei. Here, we summarize current knowledge on the impact of astrocyte and microglia activity on behavioral outcomes, with a specific focus on brain areas relevant to higher cognitive control, reward-seeking, and circadian regulation.
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Affiliation(s)
- P I Ortinski
- Department of Neuroscience, University of Kentucky, USA
| | - K J Reissner
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, USA
| | - J Turner
- Department of Pharmaceutical Sciences, University of Kentucky, USA
| | - T A Anderson
- Department of Neuroscience, University of Kentucky, USA
| | - A Scimemi
- Department of Biology, State University of New York at Albany, USA
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16
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Uchida S, Shimada C, Sakuma N, Kagitani F, Kan A, Awata S. Olfactory function and discrimination ability in the elderly: a pilot study. J Physiol Sci 2022; 72:8. [PMID: 35365090 PMCID: PMC10717643 DOI: 10.1186/s12576-022-00832-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 03/23/2022] [Indexed: 11/10/2022]
Abstract
We recently reported that subjects with a higher olfactory identification threshold for rose odor declined more in attentional ability in the elderly. This study focuses on discrimination ability and olfactory identification threshold in twelve elderly subjects living in a community (age: 80.9 ± 1.6). Olfactory function was assessed by the rose odor identification threshold. We assessed the discrimination ability by distinguishing 5 similar odor pairs. Our results showed that the subjects with a higher olfactory identification threshold (≥ 5) declined more in discrimination ability (14% ± 14%, p = 0.03) compared to those with a lower threshold (≤ 4) (averaged value set at 100%). As discrimination ability is related to the basal forebrain cholinergic system, our results suggest that olfactory impairment links to the decline in cognitive function relating the cholinergic system.
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Affiliation(s)
- Sae Uchida
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan.
| | - Chiho Shimada
- Department of Exploring End-of-Life Care for the Elderly, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
- Faculty of Humanities and Social Science, Saku University, Nagano, Japan
| | - Naoko Sakuma
- Department of Dementia and Mental Health Research, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Fusako Kagitani
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakaecho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Akiko Kan
- Department of Health Services Research, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Shuichi Awata
- Integrated Research Initiative for Living Well With Dementia, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
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17
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Woodburn SC, Bollinger JL, Wohleb ES. The semantics of microglia activation: neuroinflammation, homeostasis, and stress. J Neuroinflammation 2021; 18:258. [PMID: 34742308 PMCID: PMC8571840 DOI: 10.1186/s12974-021-02309-6] [Citation(s) in RCA: 216] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/28/2021] [Indexed: 02/08/2023] Open
Abstract
Microglia are emerging as critical regulators of neuronal function and behavior in nearly every area of neuroscience. Initial reports focused on classical immune functions of microglia in pathological contexts, however, immunological concepts from these studies have been applied to describe neuro-immune interactions in the absence of disease, injury, or infection. Indeed, terms such as 'microglia activation' or 'neuroinflammation' are used ubiquitously to describe changes in neuro-immune function in disparate contexts; particularly in stress research, where these terms prompt undue comparisons to pathological conditions. This creates a barrier for investigators new to neuro-immunology and ultimately hinders our understanding of stress effects on microglia. As more studies seek to understand the role of microglia in neurobiology and behavior, it is increasingly important to develop standard methods to study and define microglial phenotype and function. In this review, we summarize primary research on the role of microglia in pathological and physiological contexts. Further, we propose a framework to better describe changes in microglia1 phenotype and function in chronic stress. This approach will enable more precise characterization of microglia in different contexts, which should facilitate development of microglia-directed therapeutics in psychiatric and neurological disease.
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Affiliation(s)
- Samuel C Woodburn
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Justin L Bollinger
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Eric S Wohleb
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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