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Jiao H, Kalsbeek A, Yi CX. Microglia, circadian rhythm and lifestyle factors. Neuropharmacology 2024; 257:110029. [PMID: 38852838 DOI: 10.1016/j.neuropharm.2024.110029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/11/2024]
Abstract
Microglia, a vital homeostasis-keeper of the central nervous system, perform critical functions such as synaptic pruning, clearance of cellular debris, and participation in neuroinflammatory processes. Recent research has shown that microglia exhibit strong circadian rhythms that not only actively regulate their own immune activity, but also affect neuronal function. Disruptions of the circadian clock have been linked to a higher risk of developing a variety of diseases. In this article we will provide an overview of how lifestyle factors impact microglial function, with a focus on disruptions caused by irregular sleep-wake patterns, reduced physical activity, and eating at the wrong time-of-day. We will also discuss the potential connection between these lifestyle factors, disrupted circadian rhythms, and the role of microglia in keeping brain health. This article is part of the Special Issue on "Microglia".
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Affiliation(s)
- Han Jiao
- Department of Endocrinology and Metabolism, Amsterdam University Medical Center, location AMC, University of Amsterdam, Amsterdam, the Netherlands; Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, the Netherlands; Department of Clinical Chemistry, Laboratory of Endocrinology, Amsterdam University Medical Center, location AMC, Amsterdam, the Netherlands; Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Andries Kalsbeek
- Department of Endocrinology and Metabolism, Amsterdam University Medical Center, location AMC, University of Amsterdam, Amsterdam, the Netherlands; Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, the Netherlands; Department of Clinical Chemistry, Laboratory of Endocrinology, Amsterdam University Medical Center, location AMC, Amsterdam, the Netherlands; Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Chun-Xia Yi
- Department of Endocrinology and Metabolism, Amsterdam University Medical Center, location AMC, University of Amsterdam, Amsterdam, the Netherlands; Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, the Netherlands; Department of Clinical Chemistry, Laboratory of Endocrinology, Amsterdam University Medical Center, location AMC, Amsterdam, the Netherlands; Netherlands Institute for Neuroscience, Amsterdam, the Netherlands.
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2
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Liong S, Choy KHC, De Luca SN, Liong F, Coward-Smith M, Oseghale O, Miles MA, Vlahos R, Valant C, Nithianantharajah J, Pantelis C, Christopoulos A, Selemidis S. Brain region-specific alterations in gene expression trajectories in the offspring born from influenza A virus infected mice. Brain Behav Immun 2024; 120:488-498. [PMID: 38925418 DOI: 10.1016/j.bbi.2024.06.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 06/04/2024] [Accepted: 06/23/2024] [Indexed: 06/28/2024] Open
Abstract
Influenza A virus (IAV) infection during pregnancy can increase the risk for neurodevelopmental disorders in the offspring, however, the underlying neurobiological mechanisms are largely unknown. To recapitulate viral infection, preclinical studies have traditionally focused on using synthetic viral mimetics, rather than live IAV, to examine consequences of maternal immune activation (MIA)-dependent processes on offspring. In contrast, few studies have used live IAV to assess effects on global gene expression, and none to date have addressed whether moderate IAV, mimicking seasonal influenza disease, alters normal gene expression trajectories in different brain regions across different stages of development. Herein, we show that moderate IAV infection during pregnancy, which causes mild maternal disease and no overt foetal complications in utero, induces lasting effects on the offspring into adulthood. We observed behavioural changes in adult offspring, including disrupted prepulse inhibition, dopaminergic hyper-responsiveness, and spatial recognition memory deficits. Gene profiling in the offspring brain from neonate to adolescence revealed persistent alterations to normal gene expression trajectories in the prefronal cortex, hippocampus, hypothalamus and cerebellum. Alterations were found in genes involved in inflammation and neurogenesis, which were predominately dysregulated in neonatal and early adolescent offspring. Notably, late adolescent offspring born from IAV infected mice displayed altered microglial morphology in the hippocampus. In conclusion, we show that moderate IAV during pregnancy perturbs neurodevelopmental trajectories in the offspring, including alterations in the neuroinflammatory gene expression profile and microglial number and morphology in the hippocampus, resulting in behavioural changes in adult offspring. Such early perturbations may underlie the vulnerability in human offspring for the later development of neurodevelopmental disorders, including schizophrenia. Our work highlights the importance of using live IAV in developing novel preclinical models that better recapitulate the real-world impact of inflammatory insults during pregnancy on offspring neurodevelopmental trajectories and disease susceptibility later in life.
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Affiliation(s)
- Stella Liong
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - K H Christopher Choy
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Simone N De Luca
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Felicia Liong
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Madison Coward-Smith
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Osezua Oseghale
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Mark A Miles
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Ross Vlahos
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Celine Valant
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Jess Nithianantharajah
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia; Department of Florey Neuroscience, University of Melbourne, Melbourne, VIC, Australia.
| | - Christos Pantelis
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia; Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia; Neuromedicines Discovery Centre, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia.
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia; Neuromedicines Discovery Centre, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia.
| | - Stavros Selemidis
- Centre for Respiratory Science and Health, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia.
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Wan X, Cai G, Yan Z, Liu X, Yang D, Lu Y, An L, Wu S, Zhang F. PV and SST neurons in the anterior cingulate cortex regulate social disorders in adulthood induced by sensory abnormalities in childhood. CNS Neurosci Ther 2024; 30:e14863. [PMID: 39036868 PMCID: PMC11261302 DOI: 10.1111/cns.14863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 06/03/2024] [Accepted: 06/23/2024] [Indexed: 07/23/2024] Open
Abstract
OBJECTIVE Childhood sensory abnormalities experience has a crucial influence on the structure and function of the adult brain. The underlying mechanism of neurological function induced by childhood sensory abnormalities experience is still unclear. Our study was to investigate whether the GABAergic neurons in the anterior cingulate cortex (ACC) regulate social disorders caused by childhood sensory abnormalities experience. METHODS We used two mouse models, complete Freund's adjuvant (CFA) injection mice and bilateral whisker trimming (BWT) mice in childhood. We applied immunofluorescence, chemogenetic and optogenetic to study the mechanism of parvalbumin (PV) neurons and somatostatin (SST) neurons in ACC in regulating social disorders induced by sensory abnormalities in childhood. RESULTS Inflammatory pain in childhood leads to social preference disorders, while BWT in childhood leads to social novelty disorders in adult mice. Inflammatory pain and BWT in childhood caused an increase in the number of PV and SST neurons, respectively, in adult mice ACC. Inhibiting PV neurons in ACC improved social preference disorders in adult mice that experienced inflammatory pain during childhood. Inhibiting SST neurons in ACC improved social novelty disorders in adult mice that experienced BWT in childhood. CONCLUSIONS Our study reveals that PV and SST neurons of the ACC may play a critical role in regulating social disorders induced by sensory abnormalities in childhood.
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Affiliation(s)
- Xiang‐Dong Wan
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education and Department of Biochemistry and Molecular BiologyHebei Medical UniversityShijiazhuangChina
- Department of Neurobiology, School of Basic MedicineFourth Military Medical UniversityXi'anChina
| | - Guo‐Hong Cai
- Department of Neurobiology, School of Basic MedicineFourth Military Medical UniversityXi'anChina
- Department of Nuclear MedicineXijing Hospital, Fourth Military Medical UniversityXi'anChina
| | - Zi‐Qian Yan
- Graduate School of Hebei Medical UniversityShijiazhuangChina
| | - Xue‐Qing Liu
- Department of Neurobiology, School of Basic MedicineFourth Military Medical UniversityXi'anChina
| | - Ding‐Ding Yang
- Department of Neurobiology, School of Basic MedicineFourth Military Medical UniversityXi'anChina
| | - Yi‐Fan Lu
- Department of Neurobiology, School of Basic MedicineFourth Military Medical UniversityXi'anChina
| | - Lei‐Ting An
- Department of Neurobiology, School of Basic MedicineFourth Military Medical UniversityXi'anChina
| | - Sheng‐Xi Wu
- Department of Neurobiology, School of Basic MedicineFourth Military Medical UniversityXi'anChina
| | - Fan Zhang
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education and Department of Biochemistry and Molecular BiologyHebei Medical UniversityShijiazhuangChina
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Wang C, Ying Z, Pan Z. Machine unlearning in brain-inspired neural network paradigms. Front Neurorobot 2024; 18:1361577. [PMID: 38835363 PMCID: PMC11148458 DOI: 10.3389/fnbot.2024.1361577] [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: 12/26/2023] [Accepted: 03/11/2024] [Indexed: 06/06/2024] Open
Abstract
Machine unlearning, which is crucial for data privacy and regulatory compliance, involves the selective removal of specific information from a machine learning model. This study focuses on implementing machine unlearning in Spiking Neuron Models (SNMs) that closely mimic biological neural network behaviors, aiming to enhance both flexibility and ethical compliance of AI models. We introduce a novel hybrid approach for machine unlearning in SNMs, which combines selective synaptic retraining, synaptic pruning, and adaptive neuron thresholding. This methodology is designed to effectively eliminate targeted information while preserving the overall integrity and performance of the neural network. Extensive experiments were conducted on various computer vision datasets to assess the impact of machine unlearning on critical performance metrics such as accuracy, precision, recall, and ROC AUC. Our findings indicate that the hybrid approach not only maintains but in some cases enhances the neural network's performance post-unlearning. The results confirm the practicality and efficiency of our approach, underscoring its applicability in real-world AI systems.
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Affiliation(s)
- Chaoyi Wang
- Faculty of Data Science, City University of Macau, Macao, Macao SAR, China
| | - Zuobin Ying
- Faculty of Data Science, City University of Macau, Macao, Macao SAR, China
| | - Zijie Pan
- Faculty of Data Science, City University of Macau, Macao, Macao SAR, China
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DeVries SA, Conner B, Dimovasili C, Moore TL, Medalla M, Mortazavi F, Rosene DL. Immune proteins C1q and CD47 may contribute to aberrant microglia-mediated synapse loss in the aging monkey brain that is associated with cognitive impairment. GeroScience 2024; 46:2503-2519. [PMID: 37989825 PMCID: PMC10828237 DOI: 10.1007/s11357-023-01014-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 11/07/2023] [Indexed: 11/23/2023] Open
Abstract
Cognitive impairment in learning, memory, and executive function occurs in normal aging even in the absence of Alzheimer's disease (AD). While neurons do not degenerate in humans or monkeys free of AD, there are structural changes including synapse loss and dendritic atrophy, especially in the dorsolateral prefrontal cortex (dlPFC), and these correlate with cognitive age-related impairment. Developmental studies revealed activity-dependent neuronal properties that lead to synapse remodeling by microglia. Microglia-mediated phagocytosis that may eliminate synapses is regulated by immune "eat me" and "don't eat me" signaling proteins in an activity-dependent manner, so that less active synapses are eliminated. Whether this process contributes to age-related synapse loss remains unknown. The present study used a rhesus monkey model of normal aging to investigate the balance between the "eat me" signal, complement component C1q, and the "don't eat me" signal, transmembrane glycoprotein CD47, relative to age-related synapse loss in dlPFC Area 46. Results showed an age-related elevation of C1q and reduction of CD47 at PSD95+ synapses that is associated with cognitive impairment. Additionally, reduced neuronal CD47 RNA expression was found, indicating that aged neurons were less able to produce the protective signal CD47. Interestingly, microglia do not show the hypertrophic morphology indicative of phagocytic activity. These findings suggest that in the aging brain, changes in the balance of immunologic proteins give microglia instructions favoring synapse elimination of less active synapses, but this may occur by a process other than classic phagocytosis such as trogocytosis.
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Affiliation(s)
- Sarah A DeVries
- Laboratory for Cognitive Neurobiology, Department of Anatomy & Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston University Medical Campus, Boston, MA, USA.
| | - Bryce Conner
- Laboratory for Cognitive Neurobiology, Department of Anatomy & Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston University Medical Campus, Boston, MA, USA
| | - Christina Dimovasili
- Laboratory for Cognitive Neurobiology, Department of Anatomy & Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston University Medical Campus, Boston, MA, USA
| | - Tara L Moore
- Laboratory for Cognitive Neurobiology, Department of Anatomy & Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston University Medical Campus, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Maria Medalla
- Laboratory for Cognitive Neurobiology, Department of Anatomy & Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston University Medical Campus, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
| | - Farzad Mortazavi
- Laboratory for Cognitive Neurobiology, Department of Anatomy & Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston University Medical Campus, Boston, MA, USA
| | - Douglas L Rosene
- Laboratory for Cognitive Neurobiology, Department of Anatomy & Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston University Medical Campus, Boston, MA, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, USA
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McVey Neufeld SF, Ahn M, Kunze WA, McVey Neufeld KA. Adolescence, the Microbiota-Gut-Brain Axis, and the Emergence of Psychiatric Disorders. Biol Psychiatry 2024; 95:310-318. [PMID: 37839790 DOI: 10.1016/j.biopsych.2023.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/06/2023] [Accepted: 10/07/2023] [Indexed: 10/17/2023]
Abstract
Second only to early life, adolescence is a period of dramatic change and growth. For the developing young adult, this occurs against a backdrop of distinct environmental challenges and stressors. A significant body of work has identified an important role for the microbiota-gut-brain (MGB) axis in the development and function of the brain. Given that the MGB axis is both highly plastic during the teenage years and vulnerable to environmental stressors, more attention needs to be drawn to its potential role in the emergence of psychiatric illnesses, many of which first manifest during adolescence. Here, we review the current literature surrounding the developing microbiome, enteric nervous system, vagus nerve, and brain during the adolescent period. We also examine preclinical and clinical research involving the MGB axis during this dynamic developmental window and argue that more research is needed to further understand the role of the MGB in the pathogenesis of brain disorders. Greater understanding of the adolescent MGB axis will open up the exciting potential for new microbial-based therapeutics for the treatment of these often-refractory psychiatric illnesses.
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Affiliation(s)
| | - Matthew Ahn
- McMaster Brain-Body Institute at St Joseph's Healthcare, McMaster University, Hamilton, Ontario, Canada
| | - Wolfgang A Kunze
- McMaster Brain-Body Institute at St Joseph's Healthcare, McMaster University, Hamilton, Ontario, Canada
| | - Karen-Anne McVey Neufeld
- McMaster Brain-Body Institute at St Joseph's Healthcare, McMaster University, Hamilton, Ontario, Canada.
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Čechová B, Mihalčíková L, Vaculin Š, Šandera Š, Šlamberová R. Levels of BDNF and NGF in adolescent rat hippocampus neonatally exposed to methamphetamine along with environmental alterations. Physiol Res 2023; 72:S559-S571. [PMID: 38165760 PMCID: PMC10861250 DOI: 10.33549/physiolres.935216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 09/07/2023] [Indexed: 02/01/2024] Open
Abstract
Neurotrophins are proteins included in development and functioning of various processed in mammalian organisms. They are important in early development but as well as during adulthood. Brain - derived neurotrophic factor (BDNF) and nerve growth factor (NGF) have been previously linked with many psychiatric disorders such as depression and addiction. Since during postnatal development, brain undergoes various functional and anatomical changes, we included preweaning environment enrichment (EE), since enrichment has been linked with improved function and development of the several brain structure such as hippocampus (HP), in which we monitored these changes. On the other hand, social isolation has been linked with depression and anxiety-like behavior, therefore postweaning social isolation has been added to this model as well and animal were exposed to this condition till adolescence. We examined if all these three factors had impact on BDNF and NGF levels during three phases of adolescence - postnatal days (PDs) 28, 35 and 45. Our results show that EE did not increase BDNF levels neither in control or MA exposed animals and these results are similar for both direct and indirect exposure. On the other side, social separation after weaning did reduce BDNF levels in comparison to standard housing animals but this effect was reversed by direct MA exposure. In terms of NGF, EE environment increased its levels only in indirectly exposed controls and MA animals during late adolescence. On the other hand, social separation increased NGF levels in majority of animals.
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Affiliation(s)
- B Čechová
- Department of Physiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
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Bettag J, Goldenberg D, Carter J, Morfin S, Borsotti A, Fox J, ReVeal M, Natrop D, Gosser D, Kolli S, Jain AK. Gut Microbiota to Microglia: Microbiome Influences Neurodevelopment in the CNS. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1767. [PMID: 38002858 PMCID: PMC10670365 DOI: 10.3390/children10111767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 10/19/2023] [Accepted: 10/28/2023] [Indexed: 11/26/2023]
Abstract
The brain is traditionally viewed as an immunologically privileged site; however, there are known to be multiple resident immune cells that influence the CNS environment and are reactive to extra-CNS signaling. Microglia are an important component of this system, which influences early neurodevelopment in addition to modulating inflammation and regenerative responses to injury and infection. Microglia are influenced by gut microbiome-derived metabolites, both as part of their normal function and potentially in pathological patterns that may induce neurodevelopmental disabilities or behavioral changes. This review aims to summarize the mounting evidence indicating that, not only is the Gut-Brain axis mediated by metabolites and microglia throughout an organism's lifetime, but it is also influenced prenatally by maternal microbiome and diet, which holds implications for both early neuropathology and neurodevelopment.
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Affiliation(s)
- Jeffery Bettag
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - Daniel Goldenberg
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - Jasmine Carter
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - Sylvia Morfin
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - Alison Borsotti
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - James Fox
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - Matthew ReVeal
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - Dylan Natrop
- Medical College of Wisconsin-Green Bay, De Pere, WI 54115, USA;
| | - David Gosser
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - Sree Kolli
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
| | - Ajay K. Jain
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA; (D.G.); (J.C.); (S.M.); (A.B.); (J.F.); (M.R.); (D.G.); (S.K.); (A.K.J.)
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Xiao Y, Czopka T. Myelination-independent functions of oligodendrocyte precursor cells in health and disease. Nat Neurosci 2023; 26:1663-1669. [PMID: 37653126 DOI: 10.1038/s41593-023-01423-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/27/2023] [Indexed: 09/02/2023]
Abstract
Oligodendrocyte precursor cells (OPCs) are a population of tissue-resident glial cells found throughout the CNS, constituting approximately 5% of all CNS cells and persisting from development to adulthood and aging. The canonical role of OPCs is to give rise to myelinating oligodendrocytes. However, additional functions of OPCs beyond this traditional role as precursors have been suggested for a long time. In this Perspective, we provide an overview of the multiple myelination-independent functions that have been described for OPCs in the context of neuron development, angiogenesis, inflammatory response, axon regeneration and their recently discovered roles in neural circuit remodeling.
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Affiliation(s)
- Yan Xiao
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Tim Czopka
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.
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Guan PP, Ge TQ, Wang P. As a Potential Therapeutic Target, C1q Induces Synapse Loss Via Inflammasome-activating Apoptotic and Mitochondria Impairment Mechanisms in Alzheimer's Disease. J Neuroimmune Pharmacol 2023; 18:267-284. [PMID: 37386257 DOI: 10.1007/s11481-023-10076-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 06/16/2023] [Indexed: 07/01/2023]
Abstract
C1q, the initiator of the classical pathway of the complement system, is activated during Alzheimer's disease (AD) development and progression and is especially associated with the production and deposition of β-amyloid protein (Aβ) and phosphorylated tau in β-amyloid plaques (APs) and neurofibrillary tangles (NFTs). Activation of C1q is responsible for induction of synapse loss, leading to neurodegeneration in AD. Mechanistically, C1q could activate glial cells, which results in the loss of synapses via regulation of synapse pruning and phagocytosis in AD. In addition, C1q induces neuroinflammation by inducing proinflammatory cytokine secretion, which is partially mediated by inflammasome activation. Activation of inflammasomes might mediate the effects of C1q on induction of synapse apoptosis. On the other hand, activation of C1q impairs mitochondria, which hinders the renovation and regeneration of synapses. All these actions of C1q contribute to the loss of synapses during neurodegeneration in AD. Therefore, pharmacological, or genetic interventions targeting C1q may provide potential therapeutic strategies for combating AD.
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Affiliation(s)
- Pei-Pei Guan
- College of Life and Health Sciences, Northeastern University, 110819, Shenyang, People's Republic of China
| | - Tong-Qi Ge
- College of Life and Health Sciences, Northeastern University, 110819, Shenyang, People's Republic of China
| | - Pu Wang
- College of Life and Health Sciences, Northeastern University, 110819, Shenyang, People's Republic of China.
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11
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Liu H, Gao W, Cao W, Meng Q, Xu L, Kuang L, Guo Y, Cui D, Qiu J, Jiao Q, Su L, Lu G. Immediate visual reproduction negatively correlates with brain entropy of parahippocampal gyrus and inferior occipital gyrus in bipolar II disorder adolescents. BMC Psychiatry 2023; 23:515. [PMID: 37464363 DOI: 10.1186/s12888-023-05012-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 07/07/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Brain entropy reveals complexity and irregularity of brain, and it has been proven to reflect brain complexity alteration in disease states. Previous studies found that bipolar disorder adolescents showed cognitive impairment. The relationship between complexity of brain neural activity and cognition of bipolar II disorder (BD-II) adolescents remains unclear. METHODS Nineteen BD-II patients (14.63 ±1.57 years old) and seventeen age-gender matched healthy controls (HCs) (14.18 ± 1.51 years old) were enlisted. Entropy values of all voxels of the brain in resting-state functional MRI data were calculated and differences of them between BD-II and HC groups were evaluated. After that, correlation analyses were performed between entropy values of brain regions showing significant entropy differences and clinical indices in BD-II adolescents. RESULTS Significant differences were found in scores of immediate visual reproduction subtest (VR-I, p = 0.003) and Stroop color-word test (SCWT-1, p = 0.015; SCWT-2, p = 0.004; SCWT-3, p = 0.003) between the two groups. Compared with HCs, BD-II adolescents showed significant increased brain entropy in right parahippocampal gyrus and right inferior occipital gyrus. Besides, significant negative correlations between brain entropy values of right parahippocampal gyrus, right inferior occipital gyrus and immediate visual reproduction subtest scores were observed in BD-II adolescents. CONCLUSIONS The findings of the present study suggested that the disrupted function of corticolimbic system is related with cognitive abnormality of BD-II adolescents. And from the perspective temporal dynamics of brain system, the current study, brain entropy may provide available evidences for understanding the underlying neural mechanism in BD-II adolescents.
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Affiliation(s)
- Haiqin Liu
- Department of Radiology, The Second Affiliated Hospital of Shandong First Medical University, Tai'an, China
- School of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Weijia Gao
- Department of Child Psychology, The Children' s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Weifang Cao
- School of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Qingmin Meng
- Department of interventional radiology, Taian Central Hospital, Tai'an, China
| | - Longchun Xu
- Department of Radiology, The Second Affiliated Hospital of Shandong First Medical University, Tai'an, China
| | - Liangfeng Kuang
- School of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Yongxin Guo
- School of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Dong Cui
- School of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Jianfeng Qiu
- School of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China
| | - Qing Jiao
- Department of Radiology, The Second Affiliated Hospital of Shandong First Medical University, Tai'an, China.
- School of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Tai'an, China.
| | - Linyan Su
- Key Laboratory of Psychiatry and Mental Health of Hunan Province, Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, China
| | - Guangming Lu
- Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, China
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12
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Du XF, Li FN, Peng XL, Xu B, Zhang Y, Li G, Liu T, Li Y, Wang H, Yan J, Du JL. Circadian regulation of developmental synaptogenesis via the hypocretinergic system. Nat Commun 2023; 14:3195. [PMID: 37268623 DOI: 10.1038/s41467-023-38973-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/24/2023] [Indexed: 06/04/2023] Open
Abstract
The circadian clock orchestrates a wide variety of physiological and behavioral processes, enabling animals to adapt to daily environmental changes, particularly the day-night cycle. However, the circadian clock's role in the developmental processes remains unclear. Here, we employ the in vivo long-term time-lapse imaging of retinotectal synapses in the optic tectum of larval zebrafish and reveal that synaptogenesis, a fundamental developmental process for neural circuit formation, exhibits circadian rhythm. This rhythmicity arises primarily from the synapse formation rather than elimination and requires the hypocretinergic neural system. Disruption of this synaptogenic rhythm, by impairing either the circadian clock or the hypocretinergic system, affects the arrangement of the retinotectal synapses on axon arbors and the refinement of the postsynaptic tectal neuron's receptive field. Thus, our findings demonstrate that the developmental synaptogenesis is under hypocretin-dependent circadian regulation, suggesting an important role of the circadian clock in neural development.
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Affiliation(s)
- Xu-Fei Du
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China.
- University of Chinese Academy of Sciences, 19A Yu-Quan Road, 100049, Beijing, China.
| | - Fu-Ning Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
- University of Chinese Academy of Sciences, 19A Yu-Quan Road, 100049, Beijing, China
| | - Xiao-Lan Peng
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
| | - Bing Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
| | - Yu Zhang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
| | - Guang Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
| | - Taole Liu
- Center for Circadian Clocks, Soochow University, 215123, Suzhou, Jiangsu, China
- School of Biology and Basic Medical Sciences, Suzhou Medical College, Soochow University, 215123, Suzhou, Jiangsu, China
| | - Ying Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
| | - Han Wang
- Center for Circadian Clocks, Soochow University, 215123, Suzhou, Jiangsu, China
- School of Biology and Basic Medical Sciences, Suzhou Medical College, Soochow University, 215123, Suzhou, Jiangsu, China
| | - Jun Yan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
- University of Chinese Academy of Sciences, 19A Yu-Quan Road, 100049, Beijing, China
| | - Jiu-Lin Du
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China.
- University of Chinese Academy of Sciences, 19A Yu-Quan Road, 100049, Beijing, China.
- School of Life Science and Technology, ShanghaiTech University, 319 Yue-Yang Road, 200031, Shanghai, China.
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13
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LaForce GR, Philippidou P, Schaffer AE. mRNA isoform balance in neuronal development and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1762. [PMID: 36123820 PMCID: PMC10024649 DOI: 10.1002/wrna.1762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/11/2022] [Accepted: 08/15/2022] [Indexed: 11/07/2022]
Abstract
Balanced mRNA isoform diversity and abundance are spatially and temporally regulated throughout cellular differentiation. The proportion of expressed isoforms contributes to cell type specification and determines key properties of the differentiated cells. Neurons are unique cell types with intricate developmental programs, characteristic cellular morphologies, and electrophysiological potential. Neuron-specific gene expression programs establish these distinctive cellular characteristics and drive diversity among neuronal subtypes. Genes with neuron-specific alternative processing are enriched in key neuronal functions, including synaptic proteins, adhesion molecules, and scaffold proteins. Despite the similarity of neuronal gene expression programs, each neuronal subclass can be distinguished by unique alternative mRNA processing events. Alternative processing of developmentally important transcripts alters coding and regulatory information, including interaction domains, transcript stability, subcellular localization, and targeting by RNA binding proteins. Fine-tuning of mRNA processing is essential for neuronal activity and maintenance. Thus, the focus of neuronal RNA biology research is to dissect the transcriptomic mechanisms that underlie neuronal homeostasis, and consequently, predispose neuronal subtypes to disease. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Geneva R LaForce
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Polyxeni Philippidou
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ashleigh E Schaffer
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio, USA
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14
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Parajuli B, Koizumi S. Strategies for Manipulating Microglia to Determine Their Role in the Healthy and Diseased Brain. Neurochem Res 2023; 48:1066-1076. [PMID: 36085395 PMCID: PMC9462627 DOI: 10.1007/s11064-022-03742-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/08/2022] [Accepted: 08/29/2022] [Indexed: 11/30/2022]
Abstract
Microglia are the specialized macrophages of the central nervous system and play an important role in neural circuit development, modulating neurotransmission, and maintaining brain homeostasis. Microglia in normal brain is quiescent and show ramified morphology with numerous branching processes. They constantly survey their surrounding microenvironment through the extension and retraction of their processes and interact with neurons, astrocytes, and blood vessels using these processes. Microglia respond quickly to any pathological event in the brain by assuming ameboid morphology devoid of branching processes and restore homeostasis. However, when there is chronic inflammation, microglia may lose their homeostatic functions and secrete various proinflammatory cytokines and mediators that initiate neural dysfunction and neurodegeneration. In this article, we review the role of microglia in the normal brain and in various pathological brain conditions, such as Alzheimer's disease and multiple sclerosis. We describe strategies to manipulate microglia, focusing on depletion, repopulation, and replacement, and we discuss their therapeutic potential.
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Affiliation(s)
- Bijay Parajuli
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan
- GLIA Center, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
- GLIA Center, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
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15
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Wang C, Bhutta A, Zhang X, Liu F, Liu S, Latham LE, Talpos JC, Patterson TA, Slikker W. Development of a primate model to evaluate the effects of ketamine and surgical stress on the neonatal brain. Exp Biol Med (Maywood) 2023; 248:624-632. [PMID: 37208914 PMCID: PMC10350805 DOI: 10.1177/15353702231168144] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/06/2023] [Indexed: 05/21/2023] Open
Abstract
With advances in pediatric and obstetric surgery, pediatric patients are subject to complex procedures under general anesthesia. The effects of anesthetic exposure on the developing brain may be confounded by several factors including pre-existing disorders and surgery-induced stress. Ketamine, a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist, is routinely used as a pediatric general anesthetic. However, controversy remains about whether ketamine exposure may be neuroprotective or induce neuronal degeneration in the developing brain. Here, we report the effects of ketamine exposure on the neonatal nonhuman primate brain under surgical stress. Eight neonatal rhesus monkeys (postnatal days 5-7) were randomly assigned to each of two groups: Group A (n = 4) received 2 mg/kg ketamine via intravenous bolus prior to surgery and a 0.5 mg/kg/h ketamine infusion during surgery in the presence of a standardized pediatric anesthetic regimen; Group B (n = 4) received volumes of normal saline equivalent to those of ketamine given to Group A animals prior to and during surgery, also in the presence of a standardized pediatric anesthetic regimen. Under anesthesia, the surgery consisted of a thoracotomy followed by closing the pleural space and tissue in layers using standard surgical techniques. Vital signs were monitored to be within normal ranges throughout anesthesia. Elevated levels of cytokines interleukin (IL)-8, IL-15, monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein (MIP)-1β at 6 and 24 h after surgery were detected in ketamine-exposed animals. Fluoro-Jade C staining revealed significantly higher neuronal degeneration in the frontal cortex of ketamine-exposed animals, compared with control animals. Intravenous ketamine administration prior to and throughout surgery in a clinically relevant neonatal primate model appears to elevate cytokine levels and increase neuronal degeneration. Consistent with previous data on the effects of ketamine on the developing brain, the results from the current randomized controlled study in neonatal monkeys undergoing simulated surgery show that ketamine does not provide neuroprotective or anti-inflammatory effects.
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Affiliation(s)
- Cheng Wang
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, AR 72079, USA
| | - Adnan Bhutta
- University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Riley Children’s Hospital, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Xuan Zhang
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, AR 72079, USA
| | - Fang Liu
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, AR 72079, USA
| | - Shuliang Liu
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, AR 72079, USA
| | - Leah E Latham
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, AR 72079, USA
| | - John C Talpos
- Division of Neurotoxicology, National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, AR 72079, USA
| | - Tucker A Patterson
- Office of Research, National Center for Toxicological Research, Food and Drug Administration (FDA), Jefferson, AR 72079, USA
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Campos RMP, Barbosa-Silva MC, Ribeiro-Resende VT. A period of transient synaptic density unbalancing in the motor cortex after peripheral nerve injury and the involvement of microglial cells. Mol Cell Neurosci 2023; 124:103791. [PMID: 36372156 DOI: 10.1016/j.mcn.2022.103791] [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: 04/25/2022] [Revised: 11/05/2022] [Accepted: 11/06/2022] [Indexed: 11/13/2022] Open
Abstract
Some types of peripheral nerve injury lead to limb deafferentation, which leads to remodeling of body representation areas in different parts of the brain, such as in the primary motor cortex and primary sensory cortex. This plasticity is a consequence of several cellular events, such as the emergence and elimination of synapses in these areas. Beside neurons, microglial cells are intimately involved in synapse plasticity, especially in synaptic pruning. In this study, we investigated the transient changes in synaptic density in the primary motor and sensory cortex after different types of peripheral nerve injury, as well as the behavior of microglial cells in each scenario. Male C57/B6 mice were divided into a control group (no injury), sciatic-crush group, and sciatic-transection group, and treated with PBS or minocycline daily for different time points. Both types of sciatic lesion led to a significant decrease of synaptophysin and PSD-95 positive puncta counts compared to control animals 4 days after lesion (DAL), which recovered at 7 DAL and was sustained until 14 DAL. The changes in synaptic puncta density were concomitant with changes in the density and morphology of microglial cells, which were significantly more ramified in the primary motor cortex of injured animals at 1 and 4 DAL. Although the decreased synaptic puncta density overlapped with an increased number of microglial cells, the number of lysosomes per microglial cell did not increase on day 4 after lesion. Surprisingly, daily administration of minocycline increased microglial cell number and PSD-95 positive puncta density by 14 DAL. Taken together, we found evidence for transient changes in synaptic density in the primary motor, related to peripheral injury with possible participation of microglia in this plasticity process.
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Affiliation(s)
- Raquel Maria Pereira Campos
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil.
| | - Maria Carolina Barbosa-Silva
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil
| | - Victor Túlio Ribeiro-Resende
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; Núcleo Multidisciplinar de Pesquisa em Biologia (Numpex-Bio), Campus de Duque de Caxias Geraldo Guerra Cidade, Universidade Federal do Rio de Janeiro, Duque de Caxias, RJ 25255-030, Brazil
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17
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Microglial pyroptosis in hippocampus mediates sevolfurane-induced cognitive impairment in aged mice via ROS-NLRP3 inflammasome pathway. Int Immunopharmacol 2023; 116:109725. [PMID: 36764275 DOI: 10.1016/j.intimp.2023.109725] [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: 10/01/2022] [Revised: 12/17/2022] [Accepted: 01/09/2023] [Indexed: 02/10/2023]
Abstract
BACKGROUND Postoperative cognitive dysfunction (POCD) is a common complication with its pathophysiological mechanisms not been fully elucidated. Pyroptosis is a novel type of pro-inflammatory cell death and considered to be associated with cognitive dysfunction. Therefore, our study aimed to examine the effect of pyroptosis on sevoflurane-induced cognitive impairment in aged mice as well as its underlying mechanism. METHODS A mice model of cognitive impairment was established by sevoflurane exposure and the levels of reactive oxygen species (ROS), N-GSDMD, cleaved caspase-1, ASC, IL-1β and IL-18, and NLRP3 in hippocampus was determined. To explore the underlying mechanism, a pyroptosis inhibitor, necrosulfonamide (NSA), and a ROS scavenger, N-acetylcysteine (NAC), were administrated before sevoflurane exposure both in vitro and in vivo. Neurobehavioral tests, western blot, transmission electron microscope (TEM) observation, and immunofluorescence staining were performed. RESULTS Sevoflurane induced hippocampal pyroptosis in the cognitive impairment model. NSA effectively inhibited the pyroptosis and improved cognitive function. Co-labeled immunofluorescence staining suggested sevoflurane induces microglial pyroptosis. Sevoflurane induced pyroptosis accompanied with ROS accumulation in a dose-independent manner in BV2 cells, and NAC effectively reduce the levels of ROS and pyroptosis through NLRP3 inflammasome pathway in both vitro and vivo. Furthermore, NAC could also alleviate sevoflurane-induced cognitive dysfunction. CONCLUSIONS Microglial pyroptosis in hippocampus mediates sevolfurane-induced cognitive impairment in aged mice via ROS-NLRP3 inflammasome pathway. Both pyroptosis inhibition and ROS scavenging might be potential approaches to ameliorate sevoflurane-induced neurocognitive dysfunction.
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18
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The times they are a-changin': a proposal on how brain flexibility goes beyond the obvious to include the concepts of "upward" and "downward" to neuroplasticity. Mol Psychiatry 2023; 28:977-992. [PMID: 36575306 PMCID: PMC10005965 DOI: 10.1038/s41380-022-01931-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/07/2022] [Accepted: 12/14/2022] [Indexed: 12/28/2022]
Abstract
Since the brain was found to be somehow flexible, plastic, researchers worldwide have been trying to comprehend its fundamentals to better understand the brain itself, make predictions, disentangle the neurobiology of brain diseases, and finally propose up-to-date treatments. Neuroplasticity is simple as a concept, but extremely complex when it comes to its mechanisms. This review aims to bring to light an aspect about neuroplasticity that is often not given enough attention as it should, the fact that the brain's ability to change would include its ability to disconnect synapses. So, neuronal shrinkage, decrease in spine density or dendritic complexity should be included within the concept of neuroplasticity as part of its mechanisms, not as an impairment of it. To that end, we extensively describe a variety of studies involving topics such as neurodevelopment, aging, stress, memory and homeostatic plasticity to highlight how the weakening and disconnection of synapses organically permeate the brain in so many ways as a good practice of its intrinsic physiology. Therefore, we propose to break down neuroplasticity into two sub-concepts, "upward neuroplasticity" for changes related to synaptic construction and "downward neuroplasticity" for changes related to synaptic deconstruction. With these sub-concepts, neuroplasticity could be better understood from a bigger landscape as a vector in which both directions could be taken for the brain to flexibly adapt to certain demands. Such a paradigm shift would allow a better understanding of the concept of neuroplasticity to avoid any data interpretation bias, once it makes clear that there is no morality with regard to the organic and physiological changes that involve dynamic biological systems as seen in the brain.
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19
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Zhou TC, Yin CG, Wang C, Shi ZF, Tong GL. Diffusion tensor imaging analysis of the corpus callosum in children with high-risk autism spectrum disorder. Technol Health Care 2023:THC220777. [PMID: 36806528 DOI: 10.3233/thc-220777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
BACKGROUND Autism spectrum disorder (ASD) is a severe neurodevelopmental disorder that begins in early infancy and childhood and is characterized by impaired social communication and repetitive stereotyped behaviors. OBJECTIVE The purpose of this study was to examine the development of the corpus callosum and its relationship to neurobehavior in young children with high-risk (HR) ASD using magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). METHODS Twenty-one children with HR-ASD who visited Anhui Children's Hospital between January 2020 and December 2021 were selected as the study group, while 19 matched children with normal development during the same time were adopted as the control group. Cranial MRI+DTI were performed for all of the enrolled children and fractional anisotropy (FA) measurements were taken in each region of the corpus callosum. RESULTS The FA values in all regions of the corpus callosum were higher in the study group than in the control group (0.417 ± 0.016 vs. 0.412 ± 0.02 in the corpus callosum knee, 0.439 ± 0.018 vs. 0.431 ± 0.023 in the corpus callosum body, and 0.446 ± 0.017 vs. 0.434 ± 0.019 in the splenium of corpus callosum [SCC]), where the difference in the FA in the SCC was statistically significant between the two groups (P< 0.05). There was a positive correlation between the FA in the corpus callosum knee and speech scores in the neuropsychological development of the study group (P< 0.05). CONCLUSION There was a premature development tendency for corpus callosum myelination in young children with HR-ASD, and the developmental tendency was visible in the SCC. There was also a positive relationship between corpus callosum knee development and language function.
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Affiliation(s)
- Tao-Cheng Zhou
- Department of Traditional Chinese Medicine, Anhui Children's Hospital, Hefei, Anhui, China.,Department of Rehabilitation, Anhui Children's Hospital, Hefei, Anhui, China
| | - Chuan-Gao Yin
- Imaging Center, Anhui Children's Hospital, Hefei, Anhui, China
| | - Chang Wang
- Imaging Center, Anhui Children's Hospital, Hefei, Anhui, China
| | - Zi-Feng Shi
- Imaging Center, Anhui Children's Hospital, Hefei, Anhui, China
| | - Guang-Lei Tong
- Department of Rehabilitation, Anhui Children's Hospital, Hefei, Anhui, China
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20
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Dutta SB, Linneweber GA, Andriatsilavo M, Hiesinger PR, Hassan BA. EGFR-dependent suppression of synaptic autophagy is required for neuronal circuit development. Curr Biol 2023; 33:517-532.e5. [PMID: 36640763 DOI: 10.1016/j.cub.2022.12.039] [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: 04/01/2022] [Revised: 10/31/2022] [Accepted: 12/14/2022] [Indexed: 01/15/2023]
Abstract
The development of neuronal connectivity requires stabilization of dynamic axonal branches at sites of synapse formation. Models that explain how axonal branching is coupled to synaptogenesis postulate molecular regulators acting in a spatiotemporally restricted fashion to ensure branching toward future synaptic partners while also stabilizing the emerging synaptic contacts between such partners. We investigated this question using neuronal circuit development in the Drosophila brain as a model system. We report that epidermal growth factor receptor (EGFR) activity is required in presynaptic axonal branches during two distinct temporal intervals to regulate circuit wiring in the developing Drosophila visual system. EGFR is required early to regulate primary axonal branching. EGFR activity is then independently required at a later stage to prevent degradation of the synaptic active zone protein Bruchpilot (Brp). Inactivation of EGFR results in a local increase of autophagy in presynaptic branches and the translocation of active zone proteins into autophagic vesicles. The protection of synaptic material during this later interval of wiring ensures the stabilization of terminal branches, circuit connectivity, and appropriate visual behavior. Phenotypes of EGFR inactivation can be rescued by increasing Brp levels or downregulating autophagy. In summary, we identify a temporally restricted molecular mechanism required for coupling axonal branching and synaptic stabilization that contributes to the emergence of neuronal wiring specificity.
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Affiliation(s)
- Suchetana B Dutta
- Institut du Cerveau-Paris Brain Institute (ICM), Sorbonne Université, Inserm, CNRS, Hôpital Pitié Salpêtrière, 75013 Paris, France; Division of Neurobiology, Free University of Berlin, 14195 Berlin, Germany; Einstein-BIH, Charité Universitätsmedizin, 10117 Berlin, Germany
| | | | - Maheva Andriatsilavo
- Institut du Cerveau-Paris Brain Institute (ICM), Sorbonne Université, Inserm, CNRS, Hôpital Pitié Salpêtrière, 75013 Paris, France; Division of Neurobiology, Free University of Berlin, 14195 Berlin, Germany; Einstein-BIH, Charité Universitätsmedizin, 10117 Berlin, Germany
| | | | - Bassem A Hassan
- Institut du Cerveau-Paris Brain Institute (ICM), Sorbonne Université, Inserm, CNRS, Hôpital Pitié Salpêtrière, 75013 Paris, France; Division of Neurobiology, Free University of Berlin, 14195 Berlin, Germany; Einstein-BIH, Charité Universitätsmedizin, 10117 Berlin, Germany.
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21
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Das S, Ramanan N. Region-specific heterogeneity in neuronal nuclear morphology in young, aged and in Alzheimer's disease mouse brains. Front Cell Dev Biol 2023; 11:1032504. [PMID: 36819109 PMCID: PMC9929567 DOI: 10.3389/fcell.2023.1032504] [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: 08/30/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
Neurons in the mammalian brain exhibit enormous structural and functional diversity across different brain regions. Compared to our understanding of the morphological diversity of neurons, very little is known about the heterogeneity of neuronal nuclear morphology and how nuclear size changes in aging and diseased brains. Here, we report that the neuronal cell nucleus displays differences in area, perimeter, and circularity across different anatomical regions in the mouse brain. The pyramidal neurons of the hippocampal CA3 region exhibited the largest area whereas the striatal neuronal nuclei were the smallest. These nuclear size parameters also exhibited dichotomous changes with age across brain regions-while the neocortical and striatal neurons showed a decrease in nuclear area and perimeter, the CA3 neurons showed an increase with age. The nucleus of parvalbumin- and calbindin-positive interneurons had comparable morphological features but exhibited differences between brain regions. In the context of activity-dependent transcription in response to a novel environment, there was a decrease in nuclear size and circularity in c-Fos expressing neurons in the somatosensory cortex and hippocampal CA1 and CA3. In an APP/PS1 mutant mouse model of Alzheimer's disease (AD), the neuronal nuclear morphology varies with plaque size and with increasing distance from the plaque. The neuronal nuclear morphology in the immediate vicinity of the plaque was independent of the plaque size and the morphology tends to change away from the plaque. These changes in the neuronal nuclear size and shape at different ages and in AD may be attributed to changes in transcriptional activity. This study provides a detailed report on the differences that exist between neurons in nuclear morphology and can serve as a basis for future studies.
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22
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Gellért L, Luhmann HJ, Kilb W. Axonal connections between S1 barrel, M1, and S2 cortex in the newborn mouse. Front Neuroanat 2023; 17:1105998. [PMID: 36760662 PMCID: PMC9905141 DOI: 10.3389/fnana.2023.1105998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/09/2023] [Indexed: 01/26/2023] Open
Abstract
The development of functionally interconnected networks between primary (S1), secondary somatosensory (S2), and motor (M1) cortical areas requires coherent neuronal activity via corticocortical projections. However, the anatomical substrate of functional connections between S1 and M1 or S2 during early development remains elusive. In the present study, we used ex vivo carbocyanine dye (DiI) tracing in paraformaldehyde-fixed newborn mouse brain to investigate axonal projections of neurons in different layers of S1 barrel field (S1Bf), M1, and S2 toward the subplate (SP), a hub layer for sensory information transfer in the immature cortex. In addition, we performed extracellular recordings in neocortical slices to unravel the functional connectivity between these areas. Our experiments demonstrate that already at P0 neurons from the cortical plate (CP), layer 5/6 (L5/6), and the SP of both M1 and S2 send projections through the SP of S1Bf. Reciprocally, neurons from CP to SP of S1Bf send projections through the SP of M1 and S2. Electrophysiological recordings with multi-electrode arrays in cortical slices revealed weak, but functional synaptic connections between SP and L5/6 within and between S1 and M1. An even lower functional connectivity was observed between S1 and S2. In summary, our findings demonstrate that functional connections between SP and upper cortical layers are not confined to the same cortical area, but corticocortical connection between adjacent cortical areas exist already at the day of birth. Hereby, SP can integrate early cortical activity of M1, S1, and S2 and shape the development of sensorimotor integration at an early stage.
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Fan S, Qi L, Li J, Liu S, Li R, Zhan T, Li X, Wu D, Lau P, Qiu B, Bi G, Ding W. Accelerating Neurite Growth and Directing Neuronal Connections Constrained by 3D Porous Microtubes. NANO LETTERS 2022; 22:8991-8999. [PMID: 36327196 DOI: 10.1021/acs.nanolett.2c03232] [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: 06/16/2023]
Abstract
Investigation of neural growth and connection is crucial in the field of neural tissue engineering. Here, using a femtosecond laser direct writing (fs-DLW) technique, we propose a directionally aligned porous microtube array as a culture system for accelerating the growth of neurons and directing the connection of neurites. These microtubes exhibited an unprecedented guidance effect toward the outgrowth of primary embryonic rat hippocampal neurons, with a wrap resembling the myelin sheaths of neurons. The speed of neurite growth inside these microtubes was significantly faster than that outside these microtubes. We also achieved selective/directing connection of neural networks inside the magnetic microtubes via precise microtube delivery to a gap between two neural clusters. This work not only proposes a powerful microtube platform for accelerated growth of neurons but also offers a new idea for constructing biological neural circuits by arranging the size, location, and pattern of microtubes.
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Affiliation(s)
- Shengying Fan
- Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
- Department of Oncology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China
| | - Lei Qi
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui 230026, China
| | - Jiawen Li
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shunli Liu
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Rui Li
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Tongzhou Zhan
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaowei Li
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Dong Wu
- Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes, CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Pakming Lau
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui 230026, China
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bensheng Qiu
- Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guoqiang Bi
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Weiping Ding
- Department of Oncology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui 230001, China
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24
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Emina F, Kropff E. Selective connectivity enhances storage capacity in attractor models of memory function. Front Syst Neurosci 2022; 16:983147. [PMID: 36185821 PMCID: PMC9519847 DOI: 10.3389/fnsys.2022.983147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
Autoassociative neural networks provide a simple model of how memories can be stored through Hebbian synaptic plasticity as retrievable patterns of neural activity. Although progress has been made along the last decades in understanding the biological implementation of autoassociative networks, their modest theoretical storage capacity has remained a major constraint. While most previous approaches utilize randomly connected networks, here we explore the possibility of optimizing network performance by selective connectivity between neurons, that could be implemented in the brain through creation and pruning of synaptic connections. We show through numerical simulations that a reconfiguration of the connectivity matrix can improve the storage capacity of autoassociative networks up to one order of magnitude compared to randomly connected networks, either by reducing the noise or by making it reinforce the signal. Our results indicate that the signal-reinforcement scenario is not only the best performing but also the most adequate for brain-like highly diluted connectivity. In this scenario, the optimized network tends to select synapses characterized by a high consensus across stored patterns. We also introduced an online algorithm in which the network modifies its connectivity while learning new patterns. We observed that, similarly to what happens in the human brain, creation of connections dominated in an initial stage, followed by a stage characterized by pruning, leading to an equilibrium state that was independent of the initial connectivity of the network. Our results suggest that selective connectivity could be a key component to make attractor networks in the brain viable in terms of storage capacity.
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25
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Enhanced brain network flexibility by physical exercise in female methamphetamine users. Cogn Neurodyn 2022. [DOI: 10.1007/s11571-022-09848-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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26
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The Antiepileptic Drug and Toxic Teratogen Valproic Acid Alters Microglia in an Environmental Mouse Model of Autism. TOXICS 2022; 10:toxics10070379. [PMID: 35878284 PMCID: PMC9319720 DOI: 10.3390/toxics10070379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/03/2022] [Accepted: 07/06/2022] [Indexed: 12/10/2022]
Abstract
Autism spectrum disorder (ASD), a neurodevelopmental condition affecting approximately 1 in 44 children in North America, is thought to be a connectivity disorder. Valproic acid (VPA) is a multi-target drug widely used to treat epilepsy. It is also a toxic teratogen as well as a histone deacetylase inhibitor, and fetal exposure to VPA increases the risk of ASD. While the VPA model has been well-characterized for behavioral and neuronal deficits including hyperconnectivity, microglia, the principal immune cells of CNS that regulate dendrite and synapse formation during early brain development, have not been well-characterized and may provide potential hints regarding the etiology of this disorder. Therefore, in this study, we determined the effect of prenatal exposure to VPA on microglial numbers during early postnatal brain development. We found that prenatal exposure to VPA causes a significant reduction in the number of microglia in the primary motor cortex (PMC) during early postnatal brain development, particularly at postnatal day 6 (P6) and postnatal day 10 (P10) in male mice. The early microglial reduction in the VPA model coincides with active cortical synaptogenesis and is significant because it may potentially play a role in mediating impaired connectivity in ASD.
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27
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Loeb GE. Developing Intelligent Robots that Grasp Affordance. Front Robot AI 2022; 9:951293. [PMID: 35865329 PMCID: PMC9294137 DOI: 10.3389/frobt.2022.951293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 06/10/2022] [Indexed: 11/24/2022] Open
Abstract
Humans and robots operating in unstructured environments both need to classify objects through haptic exploration and use them in various tasks, but currently they differ greatly in their strategies for acquiring such capabilities. This review explores nascent technologies that promise more convergence. A novel form of artificial intelligence classifies objects according to sensory percepts during active exploration and decides on efficient sequences of exploratory actions to identify objects. Representing objects according to the collective experience of manipulating them provides a substrate for discovering causality and affordances. Such concepts that generalize beyond explicit training experiences are an important aspect of human intelligence that has eluded robots. For robots to acquire such knowledge, they will need an extended period of active exploration and manipulation similar to that employed by infants. The efficacy, efficiency and safety of such behaviors depends on achieving smooth transitions between movements that change quickly from exploratory to executive to reflexive. Animals achieve such smoothness by using a hierarchical control scheme that is fundamentally different from those of conventional robotics. The lowest level of that hierarchy, the spinal cord, starts to self-organize during spontaneous movements in the fetus. This allows its connectivity to reflect the mechanics of the musculoskeletal plant, a bio-inspired process that could be used to adapt spinal-like middleware for robots. Implementation of these extended and essential stages of fetal and infant development is impractical, however, for mechatronic hardware that does not heal and replace itself like biological tissues. Instead such development can now be accomplished in silico and then cloned into physical robots, a strategy that could transcend human performance.
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28
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Chen Y, Zhang H, Zhao Y, Zhang Y, Yin S, Hu Y, Ma G, Lu D, Sun J. Microglial integrin, chemokine receptors, and inflammatory response vary with development. Biochem Biophys Res Commun 2022; 615:94-101. [DOI: 10.1016/j.bbrc.2022.05.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/13/2022] [Accepted: 05/14/2022] [Indexed: 11/02/2022]
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29
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Aberrant Synaptic Pruning in CNS Diseases: A Critical Player in HIV-Associated Neurological Dysfunction? Cells 2022; 11:cells11121943. [PMID: 35741071 PMCID: PMC9222069 DOI: 10.3390/cells11121943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/28/2022] [Accepted: 06/14/2022] [Indexed: 02/04/2023] Open
Abstract
Even in the era of effective antiretroviral therapies, people living with Human Immunodeficiency Virus (HIV) are burdened with debilitating neurological dysfunction, such as HIV-associated neurocognitive disorders (HAND) and HIV-associated pain, for which there are no FDA approved treatments. Disruption to the neural circuits of cognition and pain in the form of synaptic degeneration is implicated in developing these dysfunctions. Glia-mediated synaptic pruning is a mechanism of structural plasticity in the healthy central nervous system (CNS), but recently, it has been discovered that dysregulated glia-mediated synaptic pruning is the cause of synaptic degeneration, leading to maladaptive plasticity and cognitive deficits in multiple diseases of the CNS. Considering the essential contribution of activated glial cells during the development of HAND and HIV-associated pain, it is possible that glia-mediated synaptic pruning is the causative mechanism of synaptic degeneration induced by HIV. This review will analyze the known examples of synaptic pruning during disease in order to better understand how this mechanism could contribute to the progression of HAND and HIV-associated pain.
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30
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Aoyama BB, Zanetti GG, Dias EV, Athié MCP, Lopes-Cendes I, Schwambach Vieira A. Transcriptomic analysis of dorsal and ventral subiculum after induction of acute seizures by electric stimulation of the perforant pathway in rats. Hippocampus 2022; 32:436-448. [PMID: 35343006 DOI: 10.1002/hipo.23417] [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: 06/22/2021] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 11/09/2022]
Abstract
Preconditioning is a mechanism in which injuries induced by non-lethal hypoxia or seizures trigger cellular resistance to subsequent events. Norwood et al., in a 2010 study, showed that an 8-h-long period of electrical stimulation of the perforant pathway in rats is required for the induction of hippocampal sclerosis. However, in order to avoid generalized seizures, status epilepticus (SE), and death, a state of resistance to seizures must be induced in the hippocampus by a preconditioning paradigm consisting of two daily 30-min stimulation periods. Due to the importance of the subiculum in the hippocampal formation, this study aims to investigate differential gene expression patterns in the dorsal and ventral subiculum using RNA-sequencing, after induction of a preconditioning protocol by electrical stimulation of the perforant pathway. The dorsal (dSub) and ventral (vSub) subiculum regions were collected by laser-microdissection 24 h after preconditioning protocol induction in rats. RNA sequencing was performed in a Hiseq 4000 platform, reads were aligned using the STAR and DESEq2 statistics package was used to estimate gene expression. We identified 1176 differentially expressed genes comparing control to preconditioned subiculum regions, 204 genes were differentially expressed in dSub and 972 in vSub. The gene ontology enrichment analysis showed that the most significant common enrichment pathway considering up-regulated genes in dSub and vSub was steroid metabolism. In contrast, the most significant enrichment pathway considering down-regulated genes in vSub was axon guidance. Our results indicate that preconditioning induces changes in the expression of genes related to synaptic reorganization, increased cholesterol metabolism, and astrogliosis in both dSub and vSub. Both regions also presented a decrease in the expression of genes related to glutamatergic transmission and an increase in expression of genes related to complement system activation and GABAergic transmission. The down-regulation of proapoptotic and axon guidance genes in the ventral subiculum suggests that preconditioning may induce a neuroprotective environment in this region.
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Affiliation(s)
- Beatriz B Aoyama
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil
| | - Gabriel G Zanetti
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil
| | - Elayne V Dias
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil
| | - Maria C P Athié
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil.,Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Iscia Lopes-Cendes
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil.,Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - André Schwambach Vieira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil
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31
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Oligodendrocyte precursor cells sculpt the visual system by regulating axonal remodeling. Nat Neurosci 2022; 25:280-284. [PMID: 35241802 PMCID: PMC8904260 DOI: 10.1038/s41593-022-01023-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 01/25/2022] [Indexed: 12/29/2022]
Abstract
Many oligodendrocyte precursor cells (OPCs) do not differentiate to form myelin, suggesting additional roles of this cell population. The zebrafish optic tectum contains OPCs in regions devoid of myelin. Elimination of these OPCs impaired precise control of retinal ganglion cell axon arbor size during formation and maturation of retinotectal connectivity and degraded functional processing of visual stimuli. Therefore, OPCs fine-tune neural circuits independently of their canonical role to make myelin. Oligodendrocyte precursor cells exist in abundance throughout the brain lifelong, with unclear functions. Xiao et al. show that, in zebrafish, these cells regulate the precise formation of retinal ganglion cell arbors and fine-tune visual processing.
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32
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A short period of early life oxytocin treatment rescues social behavior dysfunction via suppression of hippocampal hyperactivity in male mice. Mol Psychiatry 2022; 27:4157-4171. [PMID: 35840800 PMCID: PMC9718675 DOI: 10.1038/s41380-022-01692-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/22/2022] [Accepted: 06/29/2022] [Indexed: 02/07/2023]
Abstract
Early sensory experiences interact with genes to shape precise neural circuits during development. This process is vital for proper brain function in adulthood. Neurological dysfunctions caused by environmental alterations and/or genetic mutation may share the same molecular or cellular mechanisms. Here, we show that early life bilateral whisker trimming (BWT) subsequently affects social discrimination in adult male mice. Enhanced activation of the hippocampal dorsal CA3 (dCA3) in BWT mice was observed during social preference tests. Optogenetic activation of dCA3 in naive mice impaired social discrimination, whereas chemogenetic silencing of dCA3 rescued social discrimination deficit in BWT mice. Hippocampal oxytocin (OXT) is reduced after whisker trimming. Neonatal intraventricular compensation of OXT relieved dCA3 over-activation and prevented social dysfunction. Neonatal knockdown of OXT receptor in dCA3 mimics the effects of BWT, and cannot be rescued by OXT treatment. Social behavior deficits in a fragile X syndrome mouse model (Fmr1 KO mice) could also be recovered by early life OXT treatment, through negating dCA3 over-activation. Here, a possible avenue to prevent social dysfunction is uncovered.
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33
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Zhang YQ, Lin WP, Huang LP, Zhao B, Zhang CC, Yin DM. Dopamine D2 receptor regulates cortical synaptic pruning in rodents. Nat Commun 2021; 12:6444. [PMID: 34750364 PMCID: PMC8576001 DOI: 10.1038/s41467-021-26769-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 10/22/2021] [Indexed: 12/22/2022] Open
Abstract
Synaptic pruning during adolescence is important for appropriate neurodevelopment and synaptic plasticity. Aberrant synaptic pruning may underlie a variety of brain disorders such as schizophrenia, autism and anxiety. Dopamine D2 receptor (Drd2) is associated with several neuropsychiatric diseases and is the target of some antipsychotic drugs. Here we generate self-reporting Drd2 heterozygous (SR-Drd2+/-) rats to simultaneously visualize Drd2-positive neurons and downregulate Drd2 expression. Time course studies on the developing anterior cingulate cortex (ACC) from control and SR-Drd2+/- rats reveal important roles of Drd2 in regulating synaptic pruning rather than synapse formation. Drd2 also regulates LTD, a form of synaptic plasticity which includes some similar cellular/biochemical processes as synaptic pruning. We further demonstrate that Drd2 regulates synaptic pruning via cell-autonomous mechanisms involving activation of mTOR signaling. Deficits of Drd2-mediated synaptic pruning in the ACC during adolescence lead to hyper-glutamatergic function and anxiety-like behaviors in adulthood. Taken together, our results demonstrate important roles of Drd2 in cortical synaptic pruning.
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Affiliation(s)
- Ya-Qiang Zhang
- Key Laboratory of Brain Functional Genomics, Ministry of Education and Shanghai, School of Life Science, East China Normal University, 200062, Shanghai, China
| | - Wei-Peng Lin
- Key Laboratory of Brain Functional Genomics, Ministry of Education and Shanghai, School of Life Science, East China Normal University, 200062, Shanghai, China
- Joint Translational Science and Technology Research Institute, East China Normal University, 200062, Shanghai, China
| | - Li-Ping Huang
- Key Laboratory of Brain Functional Genomics, Ministry of Education and Shanghai, School of Life Science, East China Normal University, 200062, Shanghai, China
| | - Bing Zhao
- Key Laboratory of Brain Functional Genomics, Ministry of Education and Shanghai, School of Life Science, East China Normal University, 200062, Shanghai, China
| | - Cheng-Cheng Zhang
- Key Laboratory of Brain Functional Genomics, Ministry of Education and Shanghai, School of Life Science, East China Normal University, 200062, Shanghai, China
| | - Dong-Min Yin
- Key Laboratory of Brain Functional Genomics, Ministry of Education and Shanghai, School of Life Science, East China Normal University, 200062, Shanghai, China.
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34
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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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35
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Wang XL, Li L. Microglia Regulate Neuronal Circuits in Homeostatic and High-Fat Diet-Induced Inflammatory Conditions. Front Cell Neurosci 2021; 15:722028. [PMID: 34720877 PMCID: PMC8549960 DOI: 10.3389/fncel.2021.722028] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/27/2021] [Indexed: 12/12/2022] Open
Abstract
Microglia are brain resident macrophages, which actively survey the surrounding microenvironment and promote tissue homeostasis under physiological conditions. During this process, microglia participate in synaptic remodeling, neurogenesis, elimination of unwanted neurons and cellular debris. The complex interplay between microglia and neurons drives the formation of functional neuronal connections and maintains an optimal neural network. However, activation of microglia induced by chronic inflammation increases synaptic phagocytosis and leads to neuronal impairment or death. Microglial dysfunction is implicated in almost all brain diseases and leads to long-lasting functional deficiency, such as hippocampus-related cognitive decline and hypothalamus-associated energy imbalance (i.e., obesity). High-fat diet (HFD) consumption triggers mediobasal hypothalamic microglial activation and inflammation. Moreover, HFD-induced inflammation results in cognitive deficits by triggering hippocampal microglial activation. Here, we have summarized the current knowledge of microglial characteristics and biological functions and also reviewed the molecular mechanism of microglia in shaping neural circuitries mainly related to cognition and energy balance in homeostatic and diet-induced inflammatory conditions.
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Affiliation(s)
- Xiao-Lan Wang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lianjian Li
- Department of Surgery, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China.,Hubei Province Academy of Traditional Chinese Medicine, Wuhan, China
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36
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Li T, Yu D, Oak HC, Zhu B, Wang L, Jiang X, Molday RS, Kriegstein A, Piao X. Phospholipid-flippase chaperone CDC50A is required for synapse maintenance by regulating phosphatidylserine exposure. EMBO J 2021; 40:e107915. [PMID: 34585770 PMCID: PMC8561630 DOI: 10.15252/embj.2021107915] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 08/25/2021] [Accepted: 09/01/2021] [Indexed: 12/13/2022] Open
Abstract
Synaptic refinement is a critical physiological process that removes excess synapses to establish and maintain functional neuronal circuits. Recent studies have shown that focal exposure of phosphatidylserine (PS) on synapses acts as an "eat me" signal to mediate synaptic pruning. However, the molecular mechanism underlying PS externalization at synapses remains elusive. Here, we find that murine CDC50A, a chaperone of phospholipid flippases, localizes to synapses, and that its expression depends on neuronal activity. Cdc50a knockdown leads to phosphatidylserine exposure at synapses and subsequent erroneous synapse removal by microglia partly via the GPR56 pathway. Taken together, our data support that CDC50A safeguards synapse maintenance by regulating focal phosphatidylserine exposure at synapses.
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Affiliation(s)
- Tao Li
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Diankun Yu
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Hayeon C Oak
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Beika Zhu
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Li Wang
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Department of NeurologyUniversity of California, San FranciscoSan FranciscoCAUSA
| | - Xueqiao Jiang
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
| | - Robert S Molday
- Department of Biochemistry and Molecular BiologyUniversity of British ColumbiaVancouverBCCanada
| | - Arnold Kriegstein
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Department of NeurologyUniversity of California, San FranciscoSan FranciscoCAUSA
| | - Xianhua Piao
- Weill Institute for NeuroscienceUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Newborn Brain Research InstituteUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell ResearchUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
- Division of NeonatologyDepartment of PediatricsUniversity of California, San Francisco (UCSF)San FranciscoCAUSA
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37
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Kuang L, Gao W, Wang L, Guo Y, Cao W, Cui D, Jiao Q, Qiu J, Su L, Lu G. Increased resting-state brain entropy of parahippocampal gyrus and dorsolateral prefrontal cortex in manic and euthymic adolescent bipolar disorder. J Psychiatr Res 2021; 143:106-112. [PMID: 34479001 DOI: 10.1016/j.jpsychires.2021.08.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 06/01/2021] [Accepted: 08/17/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Alterations of brain signal complexity may reflect brain functional abnormalities. In adolescent bipolar disorder (ABD) distribution of brain regions showing abnormal complexity in different mood states remains unclear. We aimed to analyze brain entropy (BEN) alteration of functional magnetic resonance imaging (fMRI) signal to observe spatial distribution of complexity in ABD patients, as well as the relationship between this variation and clinical variables. METHODS Resting-state fMRI data were acquired from adolescents with bipolar disorder (BD) who were in manic (n = 19) and euthymic (n = 20) states, and from healthy controls (HCs, n = 17). The differences in BEN among the three groups, and their associations with clinical variables, were examined. RESULTS Compared to HCs, manic and euthymic ABD patients showed increased BEN in right parahippocampal gyrus (PHG) and left dorsolateral prefrontal cortex (DLPFC). There was no significant difference of BEN between the manic and the euthymic ABD groups. In manic ABD patients, right PHG BEN exhibited significantly positive relationship with episode times. CONCLUSIONS Increased BEN in right PHG and left DLPFC in ABD patients may cause dysfunction of corticolimbic circuitry which is important to emotional processing and cognitive control. The positive correlation between PHG BEN and episode times of manic ABD patients further expressed a close association between brain complexity and clinical symptoms. From the perspective of brain temporal dynamics, the present study complements previous findings that have reported corticolimbic dysfunction as an important contributor to the pathophysiology of BD. BEN may provide valuable evidences for understanding the underlying mechanism of ABD.
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Affiliation(s)
- Liangfeng Kuang
- Department of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Weijia Gao
- Department of Child Psychology, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Luoyu Wang
- Institute of Psychological Sciences, Hangzhou Normal University, Hangzhou, China; Department of Radiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yongxin Guo
- Department of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Weifang Cao
- Department of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Dong Cui
- Department of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Qing Jiao
- Department of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China.
| | - Jianfeng Qiu
- Department of Radiology, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, China
| | - Linyan Su
- Mental Health Institute of the Second Xiangya Hospital, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, China
| | - Guangming Lu
- Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Nanjing, China
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Faust TE, Gunner G, Schafer DP. Mechanisms governing activity-dependent synaptic pruning in the developing mammalian CNS. Nat Rev Neurosci 2021; 22:657-673. [PMID: 34545240 PMCID: PMC8541743 DOI: 10.1038/s41583-021-00507-y] [Citation(s) in RCA: 144] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2021] [Indexed: 02/08/2023]
Abstract
Almost 60 years have passed since the initial discovery by Hubel and Wiesel that changes in neuronal activity can elicit developmental rewiring of the central nervous system (CNS). Over this period, we have gained a more comprehensive picture of how both spontaneous neural activity and sensory experience-induced changes in neuronal activity guide CNS circuit development. Here we review activity-dependent synaptic pruning in the mammalian CNS, which we define as the removal of a subset of synapses, while others are maintained, in response to changes in neural activity in the developing nervous system. We discuss the mounting evidence that immune and cell-death molecules are important mechanistic links by which changes in neural activity guide the pruning of specific synapses, emphasizing the role of glial cells in this process. Finally, we discuss how these developmental pruning programmes may go awry in neurodevelopmental disorders of the human CNS, focusing on autism spectrum disorder and schizophrenia. Together, our aim is to give an overview of how the field of activity-dependent pruning research has evolved, led to exciting new questions and guided the identification of new, therapeutically relevant mechanisms that result in aberrant circuit development in neurodevelopmental disorders.
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Affiliation(s)
- Travis E Faust
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Georgia Gunner
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Dorothy P Schafer
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, USA.
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Prenatal Serotonin Fluctuation Affects Serotoninergic Development and Related Neural Circuits in Chicken Embryos. Neuroscience 2021; 473:66-80. [PMID: 34425158 DOI: 10.1016/j.neuroscience.2021.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 12/16/2022]
Abstract
The placenta is the primary source of serotonin (5-HT) for fetal development, programming fetal neural wiring in humans and other mammals. The fluctuation in maternal 5-HT affects fetal neurogenesis with life-long consequences, however, its mechanisms have not been well known. The chicken embryo, independent of maternal neurohormonal influence, may offer an ideal model for studying the mechanisms of prenatal 5-HT exposure altering postnatal physiological homeostasis and behavioral exhibition. To investigate the fine-tuning of 5-HT to the early embryonic neurodevelopment, 10 µg and 20 µg 5-HT were secretively injected to chicken embryos before incubation. 5-HT exposure mainly affected the neural development in the pons and midbrain, altered the serotoninergic and dopaminergic (DAergic) neuronal morphology, nucleus distribution, and their metabolisms and related gene expressions. The comprehensive effect of 5-HT exposure was not dosage-dependent but the working pathways differed, 10 µg 5-HT exposure reduced 5-HT turnover rate, increased 5-HT 1a receptor expression, and facilitated the ventral tegmental area neuronal development; while 20 µg 5-HT exposure increased the serotoninergic and DAergic neurotransmission and enhanced serotoninergic regulation to the hypothalamus. These findings indicate that the 5-HT exposure effect can be achieved via different paths by modifying the embryonic serotonergic (5-HTergic) and DAergic systems and altering fetal 5-HTergic influence on the thalamocortical circuit and hypothalamic-pituitary-adrenal axis. These results may offer a novel sight for understanding the function of 5-HT during neurodevelopment and raise the possibility for using selective 5-HT reuptake inhibitors to regulate emotional and mental wellness during early pregnancy and possible risks of complications for babies.
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40
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Stothert AR, Kaur T. Innate Immunity to Spiral Ganglion Neuron Loss: A Neuroprotective Role of Fractalkine Signaling in Injured Cochlea. Front Cell Neurosci 2021; 15:694292. [PMID: 34408629 PMCID: PMC8365835 DOI: 10.3389/fncel.2021.694292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/14/2021] [Indexed: 12/20/2022] Open
Abstract
Immune system dysregulation is increasingly being attributed to the development of a multitude of neurodegenerative diseases. This, in large part, is due to the delicate relationship that exists between neurons in the central nervous system (CNS) and peripheral nervous system (PNS), and the resident immune cells that aid in homeostasis and immune surveillance within a tissue. Classically, the inner ear was thought to be immune privileged due to the presence of a blood-labyrinth barrier. However, it is now well-established that both vestibular and auditory end organs in the inner ear contain a resident (local) population of macrophages which are the phagocytic cells of the innate-immune system. Upon cochlear sterile injury or infection, there is robust activation of these resident macrophages and a predominant increase in the numbers of macrophages as well as other types of leukocytes. Despite this, the source, nature, fate, and functions of these immune cells during cochlear physiology and pathology remains unclear. Migration of local macrophages and infiltration of bone-marrow-derived peripheral blood macrophages into the damaged cochlea occur through various signaling cascades, mediated by the release of specific chemical signals from damaged sensory and non-sensory cells of the cochlea. One such signaling pathway is CX3CL1-CX3CR1, or fractalkine (FKN) signaling, a direct line of communication between macrophages and sensory inner hair cells (IHCs) and spiral ganglion neurons (SGNs) of the cochlea. Despite the known importance of this neuron-immune axis in CNS function and pathology, until recently it was not clear whether this signaling axis played a role in macrophage chemotaxis and SGN survival following cochlear injury. In this review, we will explore the importance of innate immunity in neurodegenerative disease development, specifically focusing on the regulation of the CX3CL1-CX3CR1 axis, and present evidence for a role of FKN signaling in cochlear neuroprotection.
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Affiliation(s)
- Andrew Rigel Stothert
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
| | - Tejbeer Kaur
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
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41
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Brofiga M, Pisano M, Raiteri R, Massobrio P. On the road to the brain-on-a-chip: a review on strategies, methods, and applications. J Neural Eng 2021; 18. [PMID: 34280903 DOI: 10.1088/1741-2552/ac15e4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 07/19/2021] [Indexed: 11/12/2022]
Abstract
The brain is the most complex organ of our body. Such a complexity spans from the single-cell morphology up to the intricate connections that hundreds of thousands of neurons establish to create dense neuronal networks. All these components are involved in the genesis of the rich patterns of electrophysiological activity that characterize the brain. Over the years, researchers coming from different disciplines developedin vitrosimplified experimental models to investigate in a more controllable and observable way how neuronal ensembles generate peculiar firing rhythms, code external stimulations, or respond to chemical drugs. Nowadays, suchin vitromodels are namedbrain-on-a-chippointing out the relevance of the technological counterpart as artificial tool to interact with the brain: multi-electrode arrays are well-used devices to record and stimulate large-scale developing neuronal networks originated from dissociated cultures, brain slices, up to brain organoids. In this review, we will discuss the state of the art of the brain-on-a-chip, highlighting which structural and biological features a realisticin vitrobrain should embed (and how to achieve them). In particular, we identified two topological features, namely modular and three-dimensional connectivity, and a biological one (heterogeneity) that takes into account the huge number of neuronal types existing in the brain. At the end of this travel, we will show how 'far' we are from the goal and how interconnected-brain-regions-on-a-chip is the most appropriate wording to indicate the current state of the art.
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Affiliation(s)
- Martina Brofiga
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy
| | - Marietta Pisano
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy
| | - Roberto Raiteri
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy.,CNR- Institute of Biophysics, Genova, Italy
| | - Paolo Massobrio
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy.,National Institute for Nuclear Physics (INFN), Genova, Italy
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42
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Gorska AM, Donoso M, Valdebenito S, Prideaux B, Queen S, Scemes E, Clements J, Eugenin E. Human immunodeficiency virus-1/simian immunodeficiency virus infection induces opening of pannexin-1 channels resulting in neuronal synaptic compromise: A novel therapeutic opportunity to prevent NeuroHIV. J Neurochem 2021; 158:500-521. [PMID: 33899944 DOI: 10.1111/jnc.15374] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/27/2021] [Accepted: 04/21/2021] [Indexed: 01/16/2023]
Abstract
In healthy conditions, pannexin-1 (Panx-1) channels are in a close state, but in several pathological conditions, including human immunodeficiency virus-1 (HIV) and NeuroHIV, the channel becomes open. However, the mechanism or contribution of Panx-1 channels to the HIV pathogenesis and NeuroHIV is unknown. To determine the contribution of Panx-1 channels to the pathogenesis of NeuroHIV, we used a well-established model of simian immunodeficiency virus (SIV) infection in macaques (Macaca mulatta) in the presence of and absence of a Panx-1 blocker to later examine the synaptic/axonal compromise induced for the virus. Using Golgi's staining, we demonstrated that SIV infection compromised synaptic and axonal structures, especially in the white matter. Blocking Panx-1 channels after SIV infection prevented the synaptic and axonal compromise induced by the virus, especially by maintaining the more complex synapses. Our data demonstrated that targeting Panx-1 channels can prevent and maybe revert brain synaptic compromise induced by SIV infection.
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Affiliation(s)
- Anna Maria Gorska
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Maribel Donoso
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Silvana Valdebenito
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Brendan Prideaux
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Suzanne Queen
- Department of Molecular and Comparative Pathobiology, John Hopkins Medical Center, Baltimore, MD, USA
| | - Eliana Scemes
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Janice Clements
- Department of Molecular and Comparative Pathobiology, John Hopkins Medical Center, Baltimore, MD, USA
| | - Eliseo Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
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43
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De Schepper S, Crowley G, Hong S. Understanding microglial diversity and implications for neuronal function in health and disease. Dev Neurobiol 2021; 81:507-523. [PMID: 32757416 PMCID: PMC8438703 DOI: 10.1002/dneu.22777] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 06/21/2020] [Accepted: 07/31/2020] [Indexed: 12/22/2022]
Abstract
Genetic data implicate microglia as central players in brain health and disease, urging the need to better understand what microglia do in the brain. Microglia are critical partners in neuronal wiring and function during development and disease. Emerging literature suggests that microglia have diverse functional roles, raising the intriguing question of which functions of microglia become impaired in disease to undermine proper neuronal function. It is also becoming increasingly clear that microglia exist in heterogeneous cell states. Microglial cell states appear context-dependent, that is, age, sex, location, and health of their microenvironment; these are further influenced by external signaling factors including gut microbiota and lipid metabolites. These data altogether suggest that microglia exist in functional clusters that impact, and are impacted by, surrounding neuronal microenvironment. However, we still lack understanding of how we can translate microglia cell states into function. Here, we summarize the state-of-the-art on the diverse functions of microglia in relation to neuronal health. Then, we discuss heterogeneity during developing, healthy adult and diseased brains, and whether this may be predetermined by origin and/or regulated by local milieu. Finally, we propose that it is critical to gain high-resolution functional discernment into microglia-neuron interactions while preserving the spatial architecture of the tissue. Such insight will reveal specific targets for biomarker and therapeutic development toward microglia-neuron crosstalk in disease.
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Affiliation(s)
| | - Gerard Crowley
- UK Dementia Research InstituteUniversity College LondonLondonUK
| | - Soyon Hong
- UK Dementia Research InstituteUniversity College LondonLondonUK
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44
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Lai ESK, Nakayama H, Miyazaki T, Nakazawa T, Tabuchi K, Hashimoto K, Watanabe M, Kano M. An Autism-Associated Neuroligin-3 Mutation Affects Developmental Synapse Elimination in the Cerebellum. Front Neural Circuits 2021; 15:676891. [PMID: 34262438 PMCID: PMC8273702 DOI: 10.3389/fncir.2021.676891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 05/31/2021] [Indexed: 12/19/2022] Open
Abstract
Neuroligin is a postsynaptic cell-adhesion molecule that is involved in synapse formation and maturation by interacting with presynaptic neurexin. Mutations in neuroligin genes, including the arginine to cystein substitution at the 451st amino acid residue (R451C) of neuroligin-3 (NLGN3), have been identified in patients with autism spectrum disorder (ASD). Functional magnetic resonance imaging and examination of post-mortem brain in ASD patients implicate alteration of cerebellar morphology and Purkinje cell (PC) loss. In the present study, we examined possible association between the R451C mutation in NLGN3 and synaptic development and function in the mouse cerebellum. In NLGN3-R451C mutant mice, the expression of NLGN3 protein in the cerebellum was reduced to about 10% of the level of wild-type mice. Elimination of redundant climbing fiber (CF) to PC synapses was impaired from postnatal day 10–15 (P10–15) in NLGN3-R451C mutant mice, but majority of PCs became mono-innervated as in wild-type mice after P16. In NLGN3-R451C mutant mice, selective strengthening of a single CF relative to the other CFs in each PC was impaired from P16, which persisted into juvenile stage. Furthermore, the inhibition to excitation (I/E) balance of synaptic inputs to PCs was elevated, and calcium transients in the soma induced by strong and weak CF inputs were reduced in NLGN3-R451C mutant mice. These results suggest that a single point mutation in NLGN3 significantly influences the synapse development and refinement in cerebellar circuitry, which might be related to the pathogenesis of ASD.
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Affiliation(s)
- Esther Suk King Lai
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hisako Nakayama
- Department of Physiology, Division of Neurophysiology, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - Taisuke Miyazaki
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan.,Department of Functioning and Disability, Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | - Takanobu Nakazawa
- Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
| | - Katsuhiko Tabuchi
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,International Research Center for Neurointelligence (IRCN), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Tokyo, Japan
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Kolos EA, Korzhevskii DE. Changes in the Microglial Population during Spinal Cord Formation Indicate an Involvement of Microglia in the Regulation of Neuronogenesis and Synaptogenesis. Russ J Dev Biol 2021. [DOI: 10.1134/s1062360421030048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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46
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Zhang S, Saunders T. Mechanical processes underlying precise and robust cell matching. Semin Cell Dev Biol 2021; 120:75-84. [PMID: 34130903 DOI: 10.1016/j.semcdb.2021.06.003] [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: 03/05/2021] [Revised: 05/27/2021] [Accepted: 06/04/2021] [Indexed: 11/26/2022]
Abstract
During the development of complicated multicellular organisms, the robust formation of specific cell-cell connections (cell matching) is required for the generation of precise tissue structures. Mismatches or misconnections can lead to various diseases. Diverse mechanical cues, including differential adhesion and temporally varying cell contractility, are involved in regulating the process of cell-cell recognition and contact formation. Cells often start the process of cell matching through contact via filopodia protrusions, mediated by specific adhesion interactions at the cell surface. These adhesion interactions give rise to differential mechanical signals that can be further perceived by the cells. In conjunction with contractions generated by the actomyosin networks within the cells, this differentially coded adhesion information can be translated to reposition and sort cells. Here, we review the role of these different cell matching components and suggest how these mechanical factors cooperate with each other to facilitate specificity in cell-cell contact formation.
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Affiliation(s)
- Shaobo Zhang
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Timothy Saunders
- Mechanobiology Institute, National University of Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore; Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Proteos, Singapore; Warwick Medical School, University of Warwick, Coventry, United Kingdom.
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47
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Saxena S, Kruys V, Vamecq J, Maze M. The Role of Microglia in Perioperative Neuroinflammation and Neurocognitive Disorders. Front Aging Neurosci 2021; 13:671499. [PMID: 34122048 PMCID: PMC8193130 DOI: 10.3389/fnagi.2021.671499] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/04/2021] [Indexed: 12/14/2022] Open
Abstract
The aseptic trauma of peripheral surgery activates a systemic inflammatory response that results in neuro-inflammation; the microglia, the resident immunocompetent cells in the brain, are a key element of the neuroinflammatory response. In most settings microglia perform a surveillance role in the brain detecting and responding to “invaders” to maintain homeostasis. However, microglia have also been implicated in producing harm possibly by changing its phenotype from its beneficial, anti-inflammatory state (termed M2) into an injurious pro-inflammatory state (termed M1); it is likely that there are intermediates states between these polar phenotypes and some consider that a gradient exists with a number of intermediates, rather than a strict dichotomy between M1 and M2. In the pro-inflammatory phenotypes, microglia can disrupt synaptic plasticity such as long- term potentiation that can result in disorders of learning and memory of the type observed in Peri-operative Neurocognitive Disorders. Therefore, investigators have sought strategies to prevent microglia from provoking this adverse event in the perioperative period. In preclinical studies microglia can be depleted by removing trophic factors required for its maintenance; subsequent repopulation with a more beneficial microglial phenotype may result in memory enhancement, improved sensory motor function, as well as suppression of neuroinflammatory and oxidative stress pathways. Another approach consists of preventing microglial activation using the non-specific P38 MAP kinase blockers such as minocycline. Perhaps a more physiologic approach is the use of inhibitors of potassium (K+) channels that are required to convert the microglia into an active state. In this context the specific K+ channels that are implicated are termed Kv1.3 and KCa3.1 and high selective inhibitors for each have been developed. Data are accumulating demonstrating the utility of these K+ channel blockers in preventing Perioperative Neurocognitive Disorders.
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Affiliation(s)
- Sarah Saxena
- Department of Anesthesia, University Hospital Center (CHU de Charleroi), Charleroi, Belgium.,Department of Anesthesia and Perioperative Care, Center for Cerebrovascular Research, University of California, San Francisco, San Francisco, CA, United States
| | - Veronique Kruys
- Laboratory of Molecular Biology of the Gene, Department of Molecular Biology, ULB Immunology Research Center (UIRC), Free University of Brussels (ULB), Gosselies, Belgium
| | - Joseph Vamecq
- Inserm, CHU Lille, Univ Lille, Department of Biochemistry and Molecular Biology, Laboratory of Hormonology, Metabolism-Nutrition and Oncology (HMNO), Center of Biology and Pathology (CBP) Pierre-Marie Degand, CHRU Lille, University of North France, Lille, France
| | - Mervyn Maze
- Department of Anesthesia and Perioperative Care, Center for Cerebrovascular Research, University of California, San Francisco, San Francisco, CA, United States
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48
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Nanotechnology Facilitated Cultured Neuronal Network and Its Applications. Int J Mol Sci 2021; 22:ijms22115552. [PMID: 34074027 PMCID: PMC8197344 DOI: 10.3390/ijms22115552] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/20/2021] [Accepted: 05/20/2021] [Indexed: 12/16/2022] Open
Abstract
The development of a biomimetic neuronal network from neural cells is a big challenge for researchers. Recent advances in nanotechnology, on the other hand, have enabled unprecedented tools and techniques for guiding and directing neural stem cell proliferation and differentiation in vitro to construct an in vivo-like neuronal network. Nanotechnology allows control over neural stem cells by means of scaffolds that guide neurons to reform synaptic networks in suitable directions in 3D architecture, surface modification/nanopatterning to decide cell fate and stimulate/record signals from neurons to find out the relationships between neuronal circuit connectivity and their pathophysiological functions. Overall, nanotechnology-mediated methods facilitate precise physiochemical controls essential to develop tools appropriate for applications in neuroscience. This review emphasizes the newest applications of nanotechnology for examining central nervous system (CNS) roles and, therefore, provides an insight into how these technologies can be tested in vitro before being used in preclinical and clinical research and their potential role in regenerative medicine and tissue engineering.
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Sargolzaei S. Can Deep Learning Hit a Moving Target? A Scoping Review of Its Role to Study Neurological Disorders in Children. Front Comput Neurosci 2021; 15:670489. [PMID: 34025380 PMCID: PMC8131543 DOI: 10.3389/fncom.2021.670489] [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: 02/21/2021] [Accepted: 04/09/2021] [Indexed: 12/12/2022] Open
Abstract
Neurological disorders dramatically impact patients of any age population, their families, and societies. Pediatrics are among vulnerable age populations who differently experience the devastating consequences of neurological conditions, such as attention-deficit hyperactivity disorders (ADHD), autism spectrum disorders (ASD), cerebral palsy, concussion, and epilepsy. System-level understanding of these neurological disorders, particularly from the brain networks' dynamic perspective, has led to the significant trend of recent scientific investigations. While a dramatic maturation in the network science application domain is evident, leading to a better understanding of neurological disorders, such rapid utilization for studying pediatric neurological disorders falls behind that of the adult population. Aside from the specific technological needs and constraints in studying neurological disorders in children, the concept of development introduces uncertainty and further complexity topping the existing neurologically driven processes caused by disorders. To unravel these complexities, indebted to the availability of high-dimensional data and computing capabilities, approaches based on machine learning have rapidly emerged a new trend to understand pathways better, accurately diagnose, and better manage the disorders. Deep learning has recently gained an ever-increasing role in the era of health and medical investigations. Thanks to its relatively more minor dependency on feature exploration and engineering, deep learning may overcome the challenges mentioned earlier in studying neurological disorders in children. The current scoping review aims to explore challenges concerning pediatric brain development studies under the constraints of neurological disorders and offer an insight into the potential role of deep learning methodology on such a task with varying and uncertain nature. Along with pinpointing recent advancements, possible research directions are highlighted where deep learning approaches can assist in computationally targeting neurological disorder-related processes and translating them into windows of opportunities for interventions in diagnosis, treatment, and management of neurological disorders in children.
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Affiliation(s)
- Saman Sargolzaei
- Department of Engineering, College of Engineering and Natural Sciences, University of Tennessee at Martin, Martin, TN, United States
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50
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Kainate receptors in the developing neuronal networks. Neuropharmacology 2021; 195:108585. [PMID: 33910033 DOI: 10.1016/j.neuropharm.2021.108585] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/14/2022]
Abstract
Kainate receptors (KARs) are highly expressed in the immature brain and have unique developmentally regulated functions that may be important in linking neuronal activity to morphogenesis during activity-dependent fine-tuning of the synaptic connectivity. Altered expression of KARs in the developing neural network leads to changes in glutamatergic connectivity and network excitability, which may lead to long-lasting changes in behaviorally relevant circuitries in the brain. Here, we summarize the current knowledge on physiological and morphogenic functions described for different types of KARs at immature neural circuitries, focusing on their roles in modulating synaptic transmission and plasticity as well as circuit maturation in the rodent hippocampus and amygdala. Finally, we discuss the emerging evidence suggesting that malfunction of KARs in the immature brain may contribute to the pathophysiology underlying developmentally originating neurological disorders.
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