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Hristova MD, Krishnan T, Rossi CA, Nouza J, White A, Peebles DM, Sebire NJ, Zachary IC, David AL, Vaughan OR. Maternal Uterine Artery Adenoviral Vascular Endothelial Growth Factor (Ad.VEGF-A 165) Gene Therapy Normalises Fetal Brain Growth and Microglial Activation in Nutrient Restricted Pregnant Guinea Pigs. Reprod Sci 2024; 31:2199-2208. [PMID: 38907125 PMCID: PMC11289362 DOI: 10.1007/s43032-024-01604-w] [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: 02/02/2023] [Accepted: 05/22/2024] [Indexed: 06/23/2024]
Abstract
Fetal growth restriction (FGR) is associated with uteroplacental insufficiency, and neurodevelopmental and structural brain deficits in the infant. It is currently untreatable. We hypothesised that treating the maternal uterine artery with vascular endothelial growth factor adenoviral gene therapy (Ad.VEGF-A165) normalises offspring brain weight and prevents brain injury in a guinea pig model of FGR. Pregnant guinea pigs were fed a restricted diet before and after conception and received Ad.VEGF-A165 (1 × 1010 viral particles, n = 18) or vehicle (n = 18), delivered to the external surface of the uterine arteries, in mid-pregnancy. Pregnant, ad libitum-fed controls received vehicle only (n = 10). Offspring brain weight and histological indices of brain injury were assessed at term and 5-months postnatally. At term, maternal nutrient restriction reduced fetal brain weight and increased microglial ramification in all brain regions but did not alter indices of cell death, astrogliosis or myelination. Ad.VEGF-A165 increased brain weight and reduced microglial ramification in fetuses of nutrient restricted dams. In adult offspring, maternal nutrient restriction did not alter brain weight or markers of brain injury, whilst Ad.VEGF-A165 increased microglial ramification and astrogliosis in the hippocampus and thalamus, respectively. Ad.VEGF-A165 did not affect cell death or myelination in the fetal or offspring brain. Ad.VEGF-A165 normalises brain growth and markers of brain injury in guinea pig fetuses exposed to maternal nutrient restriction and may be a potential intervention to improve childhood neurodevelopmental outcomes in pregnancies complicated by FGR.
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Affiliation(s)
- M D Hristova
- Elizabeth Garrett Anderson Institute for Women's Health, 86-96 Chenies Mews, University College London, London, WC1E 6HX, UK
| | - T Krishnan
- Elizabeth Garrett Anderson Institute for Women's Health, 86-96 Chenies Mews, University College London, London, WC1E 6HX, UK
| | - C A Rossi
- Elizabeth Garrett Anderson Institute for Women's Health, 86-96 Chenies Mews, University College London, London, WC1E 6HX, UK
| | - J Nouza
- Elizabeth Garrett Anderson Institute for Women's Health, 86-96 Chenies Mews, University College London, London, WC1E 6HX, UK
| | - A White
- Biological Services Unit, Royal Veterinary College, London, UK
| | - D M Peebles
- Elizabeth Garrett Anderson Institute for Women's Health, 86-96 Chenies Mews, University College London, London, WC1E 6HX, UK
| | - N J Sebire
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - I C Zachary
- Centre for Cardiovascular Biology and Medicine, Division of Medicine, University College London, London, UK
| | - A L David
- Elizabeth Garrett Anderson Institute for Women's Health, 86-96 Chenies Mews, University College London, London, WC1E 6HX, UK
| | - O R Vaughan
- Elizabeth Garrett Anderson Institute for Women's Health, 86-96 Chenies Mews, University College London, London, WC1E 6HX, UK.
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2
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Zhang AY, Elias E, Manners MT. Sex-dependent astrocyte reactivity: Unveiling chronic stress-induced morphological changes across multiple brain regions. Neurobiol Dis 2024; 200:106610. [PMID: 39032799 DOI: 10.1016/j.nbd.2024.106610] [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: 05/28/2024] [Revised: 07/08/2024] [Accepted: 07/16/2024] [Indexed: 07/23/2024] Open
Abstract
Chronic stress is a major precursor to various neuropsychiatric disorders and is linked with increased inflammation in the brain. However, the bidirectional association between inflammation and chronic stress has yet to be fully understood. Astrocytes are one of the key inflammatory regulators in the brain, and the morphological change in reactive astrocytes serves as an important indicator of inflammation. In this study, we evaluated the sex-specific astrocyte response to chronic stress or systemic inflammation in key brain regions associated with mood disorders. We conducted the unpredictable chronic mild stress (UCMS) paradigm to model chronic stress, or lipopolysaccharide (LPS) injection to model systemic inflammation. To evaluate stress-induced morphological changes in astrocyte complexity, we measured GFAP fluorescent intensity for astrocyte expression, branch bifurcation by quantifying branch points and terminal points, branch arborization by conducting Sholl analysis, and calculated the ramification index. Our analysis indicated that chronic stress-induced morphological changes in astrocytes in all brain regions investigated. The effects of chronic stress were region and sex specific. Notably, females had greater stress or inflammation-induced astrocyte activation in the hypothalamus (HYPO), CA1, CA3, and amygdala (AMY) than males. These findings indicate that chronic stress induces astrocyte activation that may drive sex and region-specific effects in females, potentially contributing to sex-dependent mechanisms of disease.
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Affiliation(s)
- Ariel Y Zhang
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, NJ 08028, USA.
| | - Elias Elias
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, NJ 08028, USA.
| | - Melissa T Manners
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, NJ 08028, USA.
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3
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Baldwin KT, Murai KK, Khakh BS. Astrocyte morphology. Trends Cell Biol 2024; 34:547-565. [PMID: 38180380 DOI: 10.1016/j.tcb.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/18/2023] [Accepted: 09/29/2023] [Indexed: 01/06/2024]
Abstract
Astrocytes are predominant glial cells that tile the central nervous system (CNS). A cardinal feature of astrocytes is their complex and visually enchanting morphology, referred to as bushy, spongy, and star-like. A central precept of this review is that such complex morphological shapes evolved to allow astrocytes to contact and signal with diverse cells at a range of distances in order to sample, regulate, and contribute to the extracellular milieu, and thus participate widely in cell-cell signaling during physiology and disease. The recent use of improved imaging methods and cell-specific molecular evaluations has revealed new information on the structural organization and molecular underpinnings of astrocyte morphology, the mechanisms of astrocyte morphogenesis, and the contributions to disease states of reduced morphology. These insights have reignited interest in astrocyte morphological complexity as a cornerstone of fundamental glial biology and as a critical substrate for multicellular spatial and physiological interactions in the CNS.
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Affiliation(s)
- Katherine T Baldwin
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Montreal, QC H3G 1A4, Canada.
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90034, USA; Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90034, USA.
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4
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Bell AM, Utting C, Dickie AC, Kucharczyk MW, Quillet R, Gutierrez-Mecinas M, Razlan ANB, Cooper AH, Lan Y, Hachisuka J, Weir GA, Bannister K, Watanabe M, Kania A, Hoon MA, Macaulay IC, Denk F, Todd AJ. Deep sequencing of Phox2a nuclei reveals five classes of anterolateral system neurons. Proc Natl Acad Sci U S A 2024; 121:e2314213121. [PMID: 38805282 PMCID: PMC11161781 DOI: 10.1073/pnas.2314213121] [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: 08/29/2023] [Accepted: 04/16/2024] [Indexed: 05/30/2024] Open
Abstract
The anterolateral system (ALS) is a major ascending pathway from the spinal cord that projects to multiple brain areas and underlies the perception of pain, itch, and skin temperature. Despite its importance, our understanding of this system has been hampered by the considerable functional and molecular diversity of its constituent cells. Here, we use fluorescence-activated cell sorting to isolate ALS neurons belonging to the Phox2a-lineage for single-nucleus RNA sequencing. We reveal five distinct clusters of ALS neurons (ALS1-5) and document their laminar distribution in the spinal cord using in situ hybridization. We identify three clusters of neurons located predominantly in laminae I-III of the dorsal horn (ALS1-3) and two clusters with cell bodies located in deeper laminae (ALS4 and ALS5). Our findings reveal the transcriptional logic that underlies ALS neuronal diversity in the adult mouse and uncover the molecular identity of two previously identified classes of projection neurons. We also show that these molecular signatures can be used to target groups of ALS neurons using retrograde viral tracing. Overall, our findings provide a valuable resource for studying somatosensory biology and targeting subclasses of ALS neurons.
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Affiliation(s)
- Andrew M. Bell
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
- Small Animal Clinical Sciences, School of Biodiversity, One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | | | - Allen C. Dickie
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Mateusz W. Kucharczyk
- The Wolfson Centre for Age-Related Diseases, King’s College London, LondonWC2R 2LS, United Kingdom
- Cancer Neurophysiology Group, Lukasiewicz-PORT, Polish Center for Technology Development, Wroclaw54-066, Poland
| | - Raphaëlle Quillet
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Maria Gutierrez-Mecinas
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Aimi N. B. Razlan
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Andrew H. Cooper
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Yuxuan Lan
- Earlham Institute, NorwichNRU 7UZ, United Kingdom
| | - Junichi Hachisuka
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Greg A. Weir
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
| | - Kirsty Bannister
- The Wolfson Centre for Age-Related Diseases, King’s College London, LondonWC2R 2LS, United Kingdom
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo060-8638, Japan
| | - Artur Kania
- Neural Circuit Development Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, QCH2W 1R7, Canada
| | - Mark A. Hoon
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD 20892
| | | | - Franziska Denk
- The Wolfson Centre for Age-Related Diseases, King’s College London, LondonWC2R 2LS, United Kingdom
| | - Andrew J. Todd
- Spinal Cord Group, School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, GlasgowG12 8QQ, United Kingdom
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5
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Bell AM, Utting C, Dickie AC, Kucharczyk MW, Quillet R, Gutierrez-Mecinas M, Razlan AN, Cooper AH, Lan Y, Hachisuka J, Weir GA, Bannister K, Watanabe M, Kania A, Hoon MA, Macaulay IC, Denk F, Todd AJ. Deep sequencing of Phox2a nuclei reveals five classes of anterolateral system neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.20.553715. [PMID: 37786726 PMCID: PMC10541585 DOI: 10.1101/2023.08.20.553715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
The anterolateral system (ALS) is a major ascending pathway from the spinal cord that projects to multiple brain areas and underlies the perception of pain, itch and skin temperature. Despite its importance, our understanding of this system has been hampered by the considerable functional and molecular diversity of its constituent cells. Here we use fluorescence-activated cell sorting to isolate ALS neurons belonging to the Phox2a-lineage for single-nucleus RNA sequencing. We reveal five distinct clusters of ALS neurons (ALS1-5) and document their laminar distribution in the spinal cord using in situ hybridization. We identify 3 clusters of neurons located predominantly in laminae I-III of the dorsal horn (ALS1-3) and two clusters with cell bodies located in deeper laminae (ALS4 & ALS5). Our findings reveal the transcriptional logic that underlies ALS neuronal diversity in the adult mouse and uncover the molecular identity of two previously identified classes of projection neurons. We also show that these molecular signatures can be used to target groups of ALS neurons using retrograde viral tracing. Overall, our findings provide a valuable resource for studying somatosensory biology and targeting subclasses of ALS neurons.
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Affiliation(s)
- Andrew M. Bell
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
- School of Biodiversity, One Health and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | | | - Allen C. Dickie
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Mateusz W. Kucharczyk
- The Wolfson Centre for Age-Related Diseases, King’s College London, London WC2R 2LS, UK
- Laboratory of Neurophysiology, Department of Biochemical Toxicology, Faculty of Pharmacy, Jagiellonian University Medical College, PL30-668 Krakow, Poland
| | - Raphaëlle Quillet
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Maria Gutierrez-Mecinas
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Aimi N.B. Razlan
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Andrew H. Cooper
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | | | - Junichi Hachisuka
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Greg A. Weir
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Kirsty Bannister
- The Wolfson Centre for Age-Related Diseases, King’s College London, London WC2R 2LS, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo 060-8638, Japan
| | - Artur Kania
- Institut de Recherches Cliniques de Montréal (IRCM), Montreal, QC, H2W 1R7, Canada
| | - Mark A. Hoon
- Molecular Genetics Section, National Institute of Dental and Craniofacial Research/NIH, Bethesda, MD, USA
| | | | - Franziska Denk
- The Wolfson Centre for Age-Related Diseases, King’s College London, London WC2R 2LS, UK
| | - Andrew J. Todd
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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6
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Tan S, Faull RLM, Curtis MA. The tracts, cytoarchitecture, and neurochemistry of the spinal cord. Anat Rec (Hoboken) 2023; 306:777-819. [PMID: 36099279 DOI: 10.1002/ar.25079] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/01/2022] [Accepted: 09/11/2022] [Indexed: 11/06/2022]
Abstract
The human spinal cord can be described using a range of nomenclatures with each providing insight into its structure and function. Here we have comprehensively reviewed the key literature detailing the general structure, configuration of tracts, the cytoarchitecture of Rexed's laminae, and the neurochemistry at the spinal segmental level. The purpose of this review is to detail current anatomical understanding of how the spinal cord is structured and to aid researchers in identifying gaps in the literature that need to be studied to improve our knowledge of the spinal cord which in turn will improve the potential of therapeutic intervention for disorders of the spinal cord.
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Affiliation(s)
- Sheryl Tan
- Centre for Brain Research and Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Richard L M Faull
- Centre for Brain Research and Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Maurice A Curtis
- Centre for Brain Research and Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
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7
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Li T, Luo R, Schmidt R, D'Alessandro N, Kishore P, Zhu B, Yu D, Piao X. GPR56 S4 variant is required for microglia-mediated synaptic pruning. Glia 2023; 71:560-570. [PMID: 36336959 DOI: 10.1002/glia.24293] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 11/09/2022]
Abstract
ADGRG1 (also called GPR56) plays critical roles in brain development and wiring, including cortical lamination, central nervous system (CNS) myelination, and developmental synaptic refinement. However, the underlying mechanism(s) in mediating such diverse functions is not fully understood. Here, we investigate the function of one specific alternative splicing isoform, the GPR56 splice variant 4 (S4), to test the hypothesis that alternative splicing variants of GPR56 in part support its different functions. We created a new transgenic mouse line, Gpr56∆S4 , using CRISPR/Cas9, in which GPR56 S4 was deleted. Detailed phenotype analyses show that Gpr56∆S4 mice manifest no deficits in cortical architecture and CNS myelination compared to controls. Excitingly, they present significantly increased synapse densities, decreased synapse engulfment by microglia, and impaired eye-segregation. Taken together, our findings support that the GPR56 S4 variant is dispensable for cortical development and CNS myelination but is essential for microglia-mediated synaptic pruning.
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Affiliation(s)
- Tao Li
- Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, California, USA.,Newborn Brain Research Institute, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Rong Luo
- Sanofi, Framingham, Massachusetts, USA
| | - Rachael Schmidt
- Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, California, USA.,Newborn Brain Research Institute, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Nicholas D'Alessandro
- Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, California, USA.,Newborn Brain Research Institute, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Priya Kishore
- Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, California, USA.,Newborn Brain Research Institute, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Beika Zhu
- Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, California, USA.,Newborn Brain Research Institute, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Diankun Yu
- Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, California, USA.,Newborn Brain Research Institute, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Xianhua Piao
- Weill Institute for Neurosciences, University of California, San Francisco (UCSF), San Francisco, California, USA.,Newborn Brain Research Institute, University of California, San Francisco (UCSF), San Francisco, California, USA.,Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco (UCSF), San Francisco, California, USA.,Division of Neonatology, Department of Pediatrics, University of California, San Francisco (UCSF), San Francisco, California, USA
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8
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El-Dwairi QA, Al-Hussain SM, Banihani AS, Bataineh ZM, Djouhri L, Mustafa AG, Zaqout S. Neuronal Cell Types in the Spinal Trigeminal Nucleus of the Camel Brain. Brain Sci 2023; 13:brainsci13020312. [PMID: 36831855 PMCID: PMC9954557 DOI: 10.3390/brainsci13020312] [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: 12/20/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/15/2023] Open
Abstract
Neurons in the spinal trigeminal nucleus of a camel were morphologically studied by the Golgi impregnation method. The neurons were classified based on the size and shape of their cell bodies, the density of their dendritic trees, and the morphology and distribution of their appendages. At least 12 morphological types of neurons were found in the camel spinal trigeminal nucleus, including the following: stalked, islets, octopus-like, lobulated, boat-like, pyramidal, multipolar, round, oval, and elongated neurons. These neurons exhibited large numbers of various forms of appendages that arise not only from their dendrites but also from their cell bodies. Moreover, neurons with unique large dilatations especially at their dendritic branching points were also reported. The neurons reported in this study displayed an array of different sizes and shapes and featured various forms of appendages arising from cell bodies and dendrites. Such morphologically distinctive neuronal cell types might indicate an evolutionary adaptation to pain and temperature processing pathways at the level of the spinal trigeminal nucleus in camels, which traditionally live in a very harsh climatic environment and are frequently exposed to painful stimuli.
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Affiliation(s)
- Qasim A. El-Dwairi
- Department of Anatomy, Faculty of Medicine, Jordan University of Science & Technology, P.O. Box 3030, Irbid 22110, Jordan
| | - Saleh M. Al-Hussain
- Department of Anatomy, Faculty of Medicine, Jordan University of Science & Technology, P.O. Box 3030, Irbid 22110, Jordan
| | - Ayat S. Banihani
- Department of Rehabilitation Sciences, Faculty of Allied Medical Sciences, Jordan University of Science & Technology, P.O. Box 3030, Irbid 22110, Jordan
| | - Ziad M. Bataineh
- Department of Anatomy, Faculty of Medicine, Jordan University of Science & Technology, P.O. Box 3030, Irbid 22110, Jordan
| | - Laiche Djouhri
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
| | - Ayman G. Mustafa
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
| | - Sami Zaqout
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
- Correspondence: ; Tel.: +974-4403-7836
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9
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Renner J, Rasia-Filho AA. Morphological Features of Human Dendritic Spines. ADVANCES IN NEUROBIOLOGY 2023; 34:367-496. [PMID: 37962801 DOI: 10.1007/978-3-031-36159-3_9] [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: 11/15/2023]
Abstract
Dendritic spine features in human neurons follow the up-to-date knowledge presented in the previous chapters of this book. Human dendrites are notable for their heterogeneity in branching patterns and spatial distribution. These data relate to circuits and specialized functions. Spines enhance neuronal connectivity, modulate and integrate synaptic inputs, and provide additional plastic functions to microcircuits and large-scale networks. Spines present a continuum of shapes and sizes, whose number and distribution along the dendritic length are diverse in neurons and different areas. Indeed, human neurons vary from aspiny or "relatively aspiny" cells to neurons covered with a high density of intermingled pleomorphic spines on very long dendrites. In this chapter, we discuss the phylogenetic and ontogenetic development of human spines and describe the heterogeneous features of human spiny neurons along the spinal cord, brainstem, cerebellum, thalamus, basal ganglia, amygdala, hippocampal regions, and neocortical areas. Three-dimensional reconstructions of Golgi-impregnated dendritic spines and data from fluorescence microscopy are reviewed with ultrastructural findings to address the complex possibilities for synaptic processing and integration in humans. Pathological changes are also presented, for example, in Alzheimer's disease and schizophrenia. Basic morphological data can be linked to current techniques, and perspectives in this research field include the characterization of spines in human neurons with specific transcriptome features, molecular classification of cellular diversity, and electrophysiological identification of coexisting subpopulations of cells. These data would enlighten how cellular attributes determine neuron type-specific connectivity and brain wiring for our diverse aptitudes and behavior.
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Affiliation(s)
- Josué Renner
- Department of Basic Sciences/Physiology and Graduate Program in Biosciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil
| | - Alberto A Rasia-Filho
- Department of Basic Sciences/Physiology and Graduate Program in Biosciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil
- Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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10
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Kókai É, Alsulaiman WAA, Dickie AC, Bell AM, Goffin L, Watanabe M, Gutierrez-Mecinas M, Todd AJ. Characterisation of deep dorsal horn projection neurons in the spinal cord of the Phox2a::Cre mouse line. Mol Pain 2022; 18:17448069221119614. [PMID: 36000342 PMCID: PMC9445510 DOI: 10.1177/17448069221119614] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/20/2022] [Accepted: 07/27/2022] [Indexed: 11/16/2022] Open
Abstract
Projection neurons belonging to the anterolateral system (ALS) underlie the perception of pain, skin temperature and itch. Many ALS cells are located in laminae III-V of the dorsal horn and the adjacent lateral white matter. However, relatively little is known about the excitatory synaptic input to these deep ALS cells, and therefore about their engagement with the neuronal circuitry of the region. We have used a recently developed mouse line, Phox2a::Cre, to investigate a population of deep dorsal horn ALS neurons known as "antenna cells", which are characterised by dense innervation from peptidergic nociceptors, and to compare these with other ALS cells in the deep dorsal horn and lateral white matter. We show that these two classes differ, both in the density of excitatory synapses, and in the source of input at these synapses. Peptidergic nociceptors account for around two-thirds of the excitatory synapses on the antenna cells, but for only a small proportion of the input to the non-antenna cells. Conversely, boutons with high levels of VGLUT2, which are likely to originate mainly from glutamatergic spinal neurons, account for only ∼5% of the excitatory synapses on antenna cells, but for a much larger proportion of the input to the non-antenna cells. VGLUT1 is expressed by myelinated low-threshold mechanoreceptors and corticospinal axons, and these innervate both antenna and non-antenna cells. However, the density of VGLUT1 input to the non-antenna cells is highly variable, consistent with the view that these neurons are functionally heterogeneous.
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Affiliation(s)
- Éva Kókai
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Wafa AA Alsulaiman
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Allen C Dickie
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Andrew M Bell
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Luca Goffin
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, Japan
| | - Maria Gutierrez-Mecinas
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Andrew J Todd
- School of Psychology and Neuroscience, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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11
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NU-9 improves health of hSOD1 G93A mouse upper motor neurons in vitro, especially in combination with riluzole or edaravone. Sci Rep 2022; 12:5383. [PMID: 35354901 PMCID: PMC8967818 DOI: 10.1038/s41598-022-09332-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 03/16/2022] [Indexed: 11/27/2022] Open
Abstract
Even though amyotrophic lateral sclerosis (ALS) is a disease of the upper and lower motor neurons, to date none of the compounds in clinical trials have been tested for improving the health of diseased upper motor neurons (UMNs). There is an urgent need to develop preclinical assays that include UMN health as a readout. Since ALS is a complex disease, combinatorial treatment strategies will be required to address the mechanisms perturbed in patients. Here, we describe a novel in vitro platform that takes advantage of an UMN reporter line in which UMNs are genetically labeled with fluorescence and have misfolded SOD1 toxicity. We report that NU-9, an analog of the cyclohexane-1,3-dione family of compounds, improves the health of UMNs with misfolded SOD1 toxicity more effectively than riluzole or edaravone, -the only two FDA-approved ALS drugs to date-. Interestingly, when NU-9 is applied in combination with riluzole or edaravone, there is an additive effect on UMN health, as they extend longer axons and display enhanced branching and arborization, two important characteristics of healthy UMNs in vitro.
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12
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Yang P, Chen L, Shi Y, Zhou F, Tian H, Li J, Gao L. Progesterone alters the activation and typing of the microglia in the optic nerve crush model. Exp Eye Res 2021; 212:108805. [PMID: 34699875 DOI: 10.1016/j.exer.2021.108805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/18/2021] [Accepted: 10/21/2021] [Indexed: 12/21/2022]
Abstract
Microglia have a protective effect on the central nervous system (CNS), but their over-proliferation can cause secondary injury to the retina following optic nerve crush (ONC). Progesterone as a steroid gonadal hormone has been used in some experimental animal models for its neuroprotective effect. However, there is limited attention on the interactions between progesterone and microglia in retinal diseases. This study investigated the proliferation, morphology changes, and cell types of microglia at 3 days and 7 days after ONC. We found that progesterone treatment in unilateral optic nerve injury mice significantly reduced densities and morphological change of microglia at 7 days in the ganglion cell layer (GCL), especially in the retinal central. Inhibition of the microglia proliferation and transformation of ramified microglia into ameboid macrophages also appeared in the inner plexiform layer (IPL). Moreover, progesterone also regulated the TNF signal pathway, which was similar to the specific elimination of the M1 phenotype. M1 marks such as tumor necrosis factor alpha (TNF-α), inducible NOS(iNOS), interleukin-6 (IL-6), and Fc receptor (CD16 and CD32) significantly downregulated by progesterone treatment whether at 3 days or 7 days after ONC. On the other hand, progesterone continuously increased the expression of the M2 marks, including interleukin-4 (IL-4), arginase 1 (Arg1), and mannose receptor (CD206) since the third day, while the expression levels of transforming growth factor (TGF-β) only increased at 7 days. In general, this study elucidated the mechanism that progesterone prevented further damage on the retina by inhibiting proliferation, activation, and changing the type of microglia.
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Affiliation(s)
- Pengfei Yang
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Linchi Chen
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yongpeng Shi
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Fangfang Zhou
- College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Huanbing Tian
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Jiande Li
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Lan Gao
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
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13
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Dando SJ, Kazanis R, McMenamin PG. Myeloid Cells in the Mouse Retina and Uveal Tract Respond Differently to Systemic Inflammatory Stimuli. Invest Ophthalmol Vis Sci 2021; 62:10. [PMID: 34379096 PMCID: PMC8363776 DOI: 10.1167/iovs.62.10.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/03/2021] [Indexed: 01/14/2023] Open
Abstract
Purpose In spite of clear differences in tissue function and significance to ocular disease, little is known about how immune responses differ between the retina and uveal tract. To this end we compared the effects of acute systemic inflammation on myeloid cells within the mouse retina, iris-ciliary body, and choroid. Methods Systemic inflammation was induced in Cx3cr1gfp/gfp and CD11c-eYFP Crb1wt/wtmice by intraperitoneal lipopolysaccharide (LPS). In vivo fundus imaging was performed at two, 24, and 48 hours after LPS, and ocular tissue wholemounts were immunostained and studied by confocal microscopy. Flow cytometry was used to investigate the expression of activation markers (MHC class II, CD80, CD86) on myeloid cell populations at 24 hours. For functional studies, retinal microglia were isolated from LPS-exposed mice and cocultured with naïve OT-II CD4+ T-cells and ovalbumin peptide. T-cell proliferation was measured by flow cytometry and cytokine assays. Results Systemic LPS altered the density and morphology of retinal microglia; however, retinal microglia did not upregulate antigen presentation markers and failed to stimulate naïve CD4+ T-cell proliferation in vitro. In contrast, uveal tract myeloid cells displayed a phenotype consistent with late-activated antigen-presenting cells at 24 hours. Systemic LPS induced remodeling of myeloid populations within the uveal tract, particularly in the choroid, where dendritic cells were partially displaced by macrophages at 24 hours. Conclusions The disparate myeloid cell responses in the retina and uveal tract after systemic LPS highlight differential regulation of innate immunity within these tissue environments, observations that underpin and advance our understanding of ocular immune privilege.
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Affiliation(s)
- Samantha J. Dando
- Queensland University of Technology, Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Brisbane, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia
| | - Renee Kazanis
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia
| | - Paul G. McMenamin
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia
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14
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Leyh J, Paeschke S, Mages B, Michalski D, Nowicki M, Bechmann I, Winter K. Classification of Microglial Morphological Phenotypes Using Machine Learning. Front Cell Neurosci 2021; 15:701673. [PMID: 34267628 PMCID: PMC8276040 DOI: 10.3389/fncel.2021.701673] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/07/2021] [Indexed: 12/17/2022] Open
Abstract
Microglia are the brain's immunocompetent macrophages with a unique feature that allows surveillance of the surrounding microenvironment and subsequent reactions to tissue damage, infection, or homeostatic perturbations. Thereby, microglia's striking morphological plasticity is one of their prominent characteristics and the categorization of microglial cell function based on morphology is well established. Frequently, automated classification of microglial morphological phenotypes is performed by using quantitative parameters. As this process is typically limited to a few and especially manually chosen criteria, a relevant selection bias may compromise the resulting classifications. In our study, we describe a novel microglial classification method by morphological evaluation using a convolutional neuronal network on the basis of manually selected cells in addition to classical morphological parameters. We focused on four microglial morphologies, ramified, rod-like, activated and amoeboid microglia within the murine hippocampus and cortex. The developed method for the classification was confirmed in a mouse model of ischemic stroke which is already known to result in microglial activation within affected brain regions. In conclusion, our classification of microglial morphological phenotypes using machine learning can serve as a time-saving and objective method for post-mortem characterization of microglial changes in healthy and disease mouse models, and might also represent a useful tool for human brain autopsy samples.
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Affiliation(s)
- Judith Leyh
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Sabine Paeschke
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Bianca Mages
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | | | - Marcin Nowicki
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Ingo Bechmann
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
| | - Karsten Winter
- Institute of Anatomy, University of Leipzig, Leipzig, Germany
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15
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Fernández A, Quintana E, Velasco P, Moreno-Jimenez B, de Andrés B, Gaspar ML, Liste I, Vilar M, Mira H, Cano E. Senescent accelerated prone 8 (SAMP8) mice as a model of age dependent neuroinflammation. J Neuroinflammation 2021; 18:75. [PMID: 33736657 PMCID: PMC7977588 DOI: 10.1186/s12974-021-02104-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/03/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Aging and age-related diseases are strong risk factors for the development of neurodegenerative diseases. Neuroinflammation (NIF), as the brain's immune response, plays an important role in aged associated degeneration of central nervous system (CNS). There is a need for well characterized animal models that will allow the scientific community to understand and modulate this process. METHODS We have analyzed aging-phenotypical and inflammatory changes of brain myeloid cells (bMyC) in a senescent accelerated prone aged (SAMP8) mouse model, and compared with their senescence resistant control mice (SAMR1). We have performed morphometric methods to evaluate the architecture of cellular prolongations and determined the appearance of Iba1+ clustered cells with aging. To analyze specific constant brain areas, we have performed stereology measurements of Iba1+ cells in the hippocampal formation. We have isolated bMyC from brain parenchyma (BP) and choroid plexus plus meningeal membranes (m/Ch), and analyzed their response to systemic lipopolysaccharide (LPS)-driven inflammation. RESULTS Aged 10 months old SAMP8 mice present many of the hallmarks of aging-dependent neuroinflammation when compared with their SAMR1 control, i.e., increase of protein aggregates, presence of Iba1+ clusters, but not an increase in the number of Iba1+ cells. We have further observed an increase of main inflammatory mediator IL-1β, and an augment of border MHCII+Iba1+ cells. Isolated CD45+ bMyC from brain parenchyma (BP) and choroid plexus plus meningeal membranes (m/Ch) have been analyzed, showing that there is not a significant increase of CD45+ cells from the periphery. Our data support that aged-driven pro-inflammatory cytokine interleukin 1 beta (IL-1β) transcription is enhanced in CD45+BP cells. Furthermore, LPS-driven systemic inflammation produces inflammatory cytokines mainly in border bMyC, sensed to a lesser extent by the BP bMyC, showing that IL-1β expression is further augmented in aged SAMP8 compared to control SAMR1. CONCLUSION Our data validate the SAMP8 model to study age-associated neuroinflammatory events, but careful controls for age and strain are required. These animals show morphological changes in their bMyC cell repertoires associated to age, corresponding to an increase in the production of pro-inflammatory cytokines such as IL-1β, which predispose the brain to an enhanced inflammatory response after LPS-systemic challenge.
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Affiliation(s)
- Andrés Fernández
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Elena Quintana
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Patricia Velasco
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Belén Moreno-Jimenez
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Belén de Andrés
- Unidad de Inmunobiología, Instituto de Salud Carlos II, Madrid, Spain
| | | | - Isabel Liste
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain
| | - Marçal Vilar
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Helena Mira
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Eva Cano
- Chronic Disease Programme, Neuroinflammation Unit, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km.2,2, Majadahonda, 28220, Madrid, Spain.
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16
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Bird AD, Cuntz H. Dissecting Sholl Analysis into Its Functional Components. Cell Rep 2020; 27:3081-3096.e5. [PMID: 31167149 DOI: 10.1016/j.celrep.2019.04.097] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 09/20/2018] [Accepted: 04/19/2019] [Indexed: 12/31/2022] Open
Abstract
Sholl analysis has been an important technique in dendritic anatomy for more than 60 years. The Sholl intersection profile is obtained by counting the number of dendritic branches at a given distance from the soma and is a key measure of dendritic complexity; it has applications from evaluating the changes in structure induced by pathologies to estimating the expected number of anatomical synaptic contacts. We find that the Sholl intersection profiles of most neurons can be reproduced from three basic, functional measures: the domain spanned by the dendritic arbor, the total length of the dendrite, and the angular distribution of how far dendritic segments deviate from a direct path to the soma (i.e., the root angle distribution). The first two measures are determined by axon location and hence microcircuit structure; the third arises from optimal wiring and represents a branching statistic estimating the need for conduction speed in a neuron.
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Affiliation(s)
- Alex D Bird
- Frankfurt Institute for Advanced Studies, Frankfurt-am-Main 60438, Germany; Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt-am-Main 60528, Germany.
| | - Hermann Cuntz
- Frankfurt Institute for Advanced Studies, Frankfurt-am-Main 60438, Germany; Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt-am-Main 60528, Germany
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17
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Peirs C, Dallel R, Todd AJ. Recent advances in our understanding of the organization of dorsal horn neuron populations and their contribution to cutaneous mechanical allodynia. J Neural Transm (Vienna) 2020; 127:505-525. [PMID: 32239353 PMCID: PMC7148279 DOI: 10.1007/s00702-020-02159-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/10/2020] [Indexed: 02/07/2023]
Abstract
The dorsal horns of the spinal cord and the trigeminal nuclei in the brainstem contain neuron populations that are critical to process sensory information. Neurons in these areas are highly heterogeneous in their morphology, molecular phenotype and intrinsic properties, making it difficult to identify functionally distinct cell populations, and to determine how these are engaged in pathophysiological conditions. There is a growing consensus concerning the classification of neuron populations, based on transcriptomic and transductomic analyses of the dorsal horn. These approaches have led to the discovery of several molecularly defined cell types that have been implicated in cutaneous mechanical allodynia, a highly prevalent and difficult-to-treat symptom of chronic pain, in which touch becomes painful. The main objective of this review is to provide a contemporary view of dorsal horn neuronal populations, and describe recent advances in our understanding of on how they participate in cutaneous mechanical allodynia.
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Affiliation(s)
- Cedric Peirs
- Université Clermont Auvergne, CHU Clermont-Ferrand, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France.
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Radhouane Dallel
- Université Clermont Auvergne, CHU Clermont-Ferrand, Inserm, Neuro-Dol, Clermont-Ferrand, F-63000, France
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andrew J Todd
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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18
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Simon A, Yang M, Marrison JL, James AD, Hunt MJ, O'Toole PJ, Kaye PM, Whittington MA, Chawla S, Brackenbury WJ. Metastatic breast cancer cells induce altered microglial morphology and electrical excitability in vivo. J Neuroinflammation 2020; 17:87. [PMID: 32192526 PMCID: PMC7081703 DOI: 10.1186/s12974-020-01753-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/20/2020] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND An emerging problem in the treatment of breast cancer is the increasing incidence of metastases to the brain. Metastatic brain tumours are incurable and can cause epileptic seizures and cognitive impairment, so better understanding of this niche, and the cellular mechanisms, is urgently required. Microglia are the resident brain macrophage population, becoming "activated" by neuronal injury, eliciting an inflammatory response. Microglia promote proliferation, angiogenesis and invasion in brain tumours and metastases. However, the mechanisms underlying microglial involvement appear complex and better models are required to improve understanding of function. METHODS Here, we sought to address this need by developing a model to study metastatic breast cancer cell-microglial interactions using intravital imaging combined with ex vivo electrophysiology. We implanted an optical window on the parietal bone to facilitate observation of cellular behaviour in situ in the outer cortex of heterozygous Cx3cr1GFP/+ mice. RESULTS We detected GFP-expressing microglia in Cx3cr1GFP/+ mice up to 350 μm below the window without significant loss of resolution. When DsRed-expressing metastatic MDA-MB-231 breast cancer cells were implanted in Matrigel under the optical window, significant accumulation of activated microglia around invading tumour cells could be observed. This inflammatory response resulted in significant cortical disorganisation and aberrant spontaneously-occurring local field potential spike events around the metastatic site. CONCLUSIONS These data suggest that peritumoral microglial activation and accumulation may play a critical role in local tissue changes underpinning aberrant cortical activity, which offers a possible mechanism for the disrupted cognitive performance and seizures seen in patients with metastatic breast cancer.
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Affiliation(s)
- Anna Simon
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
- Bioscience Technology Facility, Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Ming Yang
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Joanne L Marrison
- Bioscience Technology Facility, Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Andrew D James
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Mark J Hunt
- Hull York Medical School, Heslington, York, YO10 5DD, UK
| | - Peter J O'Toole
- Bioscience Technology Facility, Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Paul M Kaye
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
- Hull York Medical School, Heslington, York, YO10 5DD, UK
- Department of Biology and York Biomedical Research Institute, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK
| | - Miles A Whittington
- Hull York Medical School, Heslington, York, YO10 5DD, UK
- Department of Biology and York Biomedical Research Institute, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK
| | - Sangeeta Chawla
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK.
- Department of Biology and York Biomedical Research Institute, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK.
| | - William J Brackenbury
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK.
- Department of Biology and York Biomedical Research Institute, University of York, Wentworth Way, Heslington, York, YO10 5DD, UK.
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19
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Smith TM, Lee D, Bradley K, McMahon SB. Methodology for quantifying excitability of identified projection neurons in the dorsal horn of the spinal cord, specifically to study spinal cord stimulation paradigms. J Neurosci Methods 2020; 330:108479. [DOI: 10.1016/j.jneumeth.2019.108479] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 10/22/2019] [Indexed: 11/28/2022]
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20
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Gruia KA, Dobrea RC, Simion CP, Dima C, Grecu A, Hudea OS, Marin M, Andronache I, Peptenatu D. The Use of Sholl and Kolmogorov Complexity Analysis in Researching on the Sustainable Development of Creative Economies in the Development Region of Bucharest‒Ilfov, Romania. SUSTAINABILITY 2019; 11:6195. [DOI: 10.3390/su11226195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Nowadays, creative economies stand as a relevant indicator of the sustainable development of local and regional ones. The study aims to highlight the spatial behaviour of creative economies in the Bucharest‒Ilfov Development Region, the most dynamic and complex regional economy in Romania. In order to assess the spatial dynamics of creative economies in the region, an economic database was created, at the level of the territorial administrative unit, for the two economic indicators considered important for the study, number of employees and turnover, under the auspices of the Classification of National Economy Activities (NACE). The establishment of creative economies was made following the Government Decision no. 859 of 2014, with 66 codes for this sector. Annual cartographic models were developed for each indicator in QGIS (a free and open–source cross–platform desktop geographic information system application that supports viewing, editing, and analysis of geospatial data), for the period 2000–2016. For a relevant analysis of spatial behaviour, we used Sholl and Kolmogorov complexity, which highlighted specific patterns of spatial dynamics that help us to understand the role of creative economies in the sustainable development of regional economies. The results highlighted the role of accessibility corridors in the development of the regional economy.
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21
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Dando SJ, Kazanis R, Chinnery HR, McMenamin PG. Regional and functional heterogeneity of antigen presenting cells in the mouse brain and meninges. Glia 2018; 67:935-949. [DOI: 10.1002/glia.23581] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 10/11/2018] [Accepted: 11/27/2018] [Indexed: 01/02/2023]
Affiliation(s)
- Samantha J. Dando
- Department of Anatomy and Developmental BiologyMonash Biomedicine Discovery Institute, Monash University Clayton Victoria Australia
| | - Renee Kazanis
- Department of Anatomy and Developmental BiologyMonash Biomedicine Discovery Institute, Monash University Clayton Victoria Australia
| | - Holly R. Chinnery
- Department of Optometry and Vision SciencesThe University of Melbourne Parkville Victoria Australia
| | - Paul G. McMenamin
- Department of Anatomy and Developmental BiologyMonash Biomedicine Discovery Institute, Monash University Clayton Victoria Australia
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22
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Beamer EH, Jurado-Arjona J, Jimenez-Mateos EM, Morgan J, Reschke CR, Kenny A, de Leo G, Olivos-Oré LA, Arribas-Blázquez M, Madden SF, Merchán-Rubira J, Delanty N, Farrell MA, O'Brien DF, Avila J, Diaz-Hernandez M, Miras-Portugal MT, Artalejo AR, Hernandez F, Henshall DC, Engel T. MicroRNA-22 Controls Aberrant Neurogenesis and Changes in Neuronal Morphology After Status Epilepticus. Front Mol Neurosci 2018; 11:442. [PMID: 30618601 PMCID: PMC6298134 DOI: 10.3389/fnmol.2018.00442] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/16/2018] [Indexed: 12/12/2022] Open
Abstract
Prolonged seizures (status epilepticus, SE) may drive hippocampal dysfunction and epileptogenesis, at least partly, through an elevation in neurogenesis, dysregulation of migration and aberrant dendritic arborization of newly-formed neurons. MicroRNA-22 was recently found to protect against the development of epileptic foci, but the mechanisms remain incompletely understood. Here, we investigated the contribution of microRNA-22 to SE-induced aberrant adult neurogenesis. SE was induced by intraamygdala microinjection of kainic acid (KA) to model unilateral hippocampal neuropathology in mice. MicroRNA-22 expression was suppressed using specific oligonucleotide inhibitors (antagomir-22) and newly-formed neurons were visualized using the thymidine analog iodo-deoxyuridine (IdU) and a green fluorescent protein (GFP)-expressing retrovirus to visualize the dendritic tree and synaptic spines. Using this approach, we quantified differences in the rate of neurogenesis and migration, the structure of the apical dendritic tree and density and morphology of dendritic spines in newly-formed neurons.SE resulted in an increased rate of hippocampal neurogenesis, including within the undamaged contralateral dentate gyrus (DG). Newly-formed neurons underwent aberrant migration, both within the granule cell layer and into ectopic sites. Inhibition of microRNA-22 exacerbated these changes. The dendritic diameter and the density and average volume of dendritic spines were unaffected by SE, but these parameters were all elevated in mice in which microRNA-22 was suppressed. MicroRNA-22 inhibition also reduced the length and complexity of the dendritic tree, independently of SE. These data indicate that microRNA-22 is an important regulator of morphogenesis of newly-formed neurons in adults and plays a role in supressing aberrant neurogenesis associated with SE.
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Affiliation(s)
- Edward H Beamer
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Jeronimo Jurado-Arjona
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.,Department of Molecular Biology, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Centro Investigación Biomédica en Red Enfermedades Neurodegenerativa (CIBERNED), Madrid, Spain
| | - Eva M Jimenez-Mateos
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - James Morgan
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Cristina R Reschke
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.,FutureNeuro Research Centre, RCSI, Dublin, Ireland
| | - Aidan Kenny
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Gioacchino de Leo
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Luis A Olivos-Oré
- Department of Pharmacology and Toxicology, Veterinary Faculty, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, Madrid, Spain
| | - Marina Arribas-Blázquez
- Department of Pharmacology and Toxicology, Veterinary Faculty, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, Madrid, Spain
| | - Stephen F Madden
- Data Science Centre, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Jesús Merchán-Rubira
- Department of Molecular Biology, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Centro Investigación Biomédica en Red Enfermedades Neurodegenerativa (CIBERNED), Madrid, Spain
| | - Norman Delanty
- FutureNeuro Research Centre, RCSI, Dublin, Ireland.,Beaumont Hospital, Dublin, Ireland
| | | | | | - Jesus Avila
- Department of Molecular Biology, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Centro Investigación Biomédica en Red Enfermedades Neurodegenerativa (CIBERNED), Madrid, Spain
| | - Miguel Diaz-Hernandez
- Department of Biochemistry and Molecular Biology, Veterinary Faculty, Universidad Complutense de Madrid, Madrid, Spain
| | - M Teresa Miras-Portugal
- Department of Biochemistry and Molecular Biology, Veterinary Faculty, Universidad Complutense de Madrid, Madrid, Spain
| | - Antonio R Artalejo
- Department of Pharmacology and Toxicology, Veterinary Faculty, Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, Madrid, Spain
| | - Felix Hernandez
- Department of Molecular Biology, Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Centro Investigación Biomédica en Red Enfermedades Neurodegenerativa (CIBERNED), Madrid, Spain
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.,FutureNeuro Research Centre, RCSI, Dublin, Ireland
| | - Tobias Engel
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.,FutureNeuro Research Centre, RCSI, Dublin, Ireland
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23
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Merighi A. The histology, physiology, neurochemistry and circuitry of the substantia gelatinosa Rolandi (lamina II) in mammalian spinal cord. Prog Neurobiol 2018; 169:91-134. [PMID: 29981393 DOI: 10.1016/j.pneurobio.2018.06.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 06/07/2018] [Accepted: 06/30/2018] [Indexed: 02/06/2023]
Abstract
The substantia gelatinosa Rolandi (SGR) was first described about two centuries ago. In the following decades an enormous amount of information has permitted us to understand - at least in part - its role in the initial processing of pain and itch. Here, I will first provide a comprehensive picture of the histology, physiology, and neurochemistry of the normal SGR. Then, I will analytically discuss the SGR circuits that have been directly demonstrated or deductively envisaged in the course of the intensive research on this area of the spinal cord, with particular emphasis on the pathways connecting the primary afferent fibers and the intrinsic neurons. The perspective existence of neurochemically-defined sets of primary afferent neurons giving rise to these circuits will be also discussed, with the proposition that a cross-talk between different subsets of peptidergic fibers may be the structural and functional substrate of additional gating mechanisms in SGR. Finally, I highlight the role played by slow acting high molecular weight modulators in these gating mechanisms.
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Affiliation(s)
- Adalberto Merighi
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, I-10095 Grugliasco (TO), Italy.
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24
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De Luca SN, Ziko I, Dhuna K, Sominsky L, Tolcos M, Stokes L, Spencer SJ. Neonatal overfeeding by small-litter rearing sensitises hippocampal microglial responses to immune challenge: Reversal with neonatal repeated injections of saline or minocycline. J Neuroendocrinol 2017; 29. [PMID: 28983991 DOI: 10.1111/jne.12540] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/22/2017] [Accepted: 10/01/2017] [Indexed: 01/08/2023]
Abstract
The early-life period is extremely vulnerable to programming effects from the environment, many of which persist into adulthood. We have previously demonstrated that adult rats overfed as neonates have hypothalamic microglia that are hyper-responsive to an immune challenge, as well as hippocampal microglia that respond less efficiently to learning. We therefore hypothesised that neonatal overfeeding would alter the ability of hippocampal microglia to respond to an immune challenge with lipopolysaccharide (LPS) and that concomitant minocycline, a tetracycline antibiotic that suppresses microglial activity, could restore these responses. We induced neonatal overfeeding by manipulating the litter sizes in which Wistar rat pups were raised, so the pups were suckled in litters of four (neonatally overfed) or 12 (control-fed). We then examined the hippocampal microglial profiles 24 hour after an immune challenge with LPS and found that the neonatally overfed rats had dramatically increased microglial numbers in the hippocampus after immune challenge compared to control-fed rats. Attempts to reverse these effects with minocycline revealed repeated that neonatal injections, whether with minocycline or with saline, markedly suppressed microglial number and density throughout the hippocampus and abolished the difference between the groups in their responses to LPS. These data suggest that neonatal overfeeding not only can have lasting effects on hippocampal immune responses, but also that neonatal exposure to a protocol of repeated injections, irrespective of treatment, has a pronounced long-term impact, highlighting the importance of considering these effects when interpreting experimental data.
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Affiliation(s)
- S N De Luca
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - I Ziko
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - K Dhuna
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - L Sominsky
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - M Tolcos
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - L Stokes
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, UK
| | - S J Spencer
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
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25
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Post-natal Deletion of Neuronal cAMP Responsive-Element Binding (CREB)-1 Promotes Pro-inflammatory Changes in the Mouse Hippocampus. Neurochem Res 2017; 42:2230-2245. [DOI: 10.1007/s11064-017-2233-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 03/08/2017] [Accepted: 03/11/2017] [Indexed: 12/19/2022]
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26
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Palombo M, Ligneul C, Najac C, Le Douce J, Flament J, Escartin C, Hantraye P, Brouillet E, Bonvento G, Valette J. New paradigm to assess brain cell morphology by diffusion-weighted MR spectroscopy in vivo. Proc Natl Acad Sci U S A 2016; 113:6671-6. [PMID: 27226303 PMCID: PMC4914152 DOI: 10.1073/pnas.1504327113] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The brain is one of the most complex organs, and tools are lacking to assess its cellular morphology in vivo. Here we combine original diffusion-weighted magnetic resonance (MR) spectroscopy acquisition and novel modeling strategies to explore the possibility of quantifying brain cell morphology noninvasively. First, the diffusion of cell-specific metabolites is measured at ultra-long diffusion times in the rodent and primate brain in vivo to observe how cell long-range morphology constrains metabolite diffusion. Massive simulations of particles diffusing in synthetic cells parameterized by morphometric statistics are then iterated to fit experimental data. This method yields synthetic cells (tentatively neurons and astrocytes) that exhibit striking qualitative and quantitative similarities with histology (e.g., using Sholl analysis). With our approach, we measure major interspecies difference regarding astrocytes, whereas dendritic organization appears better conserved throughout species. This work suggests that the time dependence of metabolite diffusion coefficient allows distinguishing and quantitatively characterizing brain cell morphologies noninvasively.
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Affiliation(s)
- Marco Palombo
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France;
| | - Clémence Ligneul
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Chloé Najac
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Juliette Le Douce
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Julien Flament
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Service (UMS) 27, INSERM, F-92260 Fontenay-aux-Roses, France
| | - Carole Escartin
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Philippe Hantraye
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Service (UMS) 27, INSERM, F-92260 Fontenay-aux-Roses, France
| | - Emmanuel Brouillet
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Gilles Bonvento
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France
| | - Julien Valette
- MIRCen, Institut d'Imagerie Biomédicale, Direction de la Recherche Fondamentale, Commissariat à l'Energie Atomique et aux Energies Alternatives, F-92260 Fontenay-aux-Roses, France; Unité Mixte de Recherche (UMR) 9199 (Neurodegenerative Diseases Laboratory), Université Paris-Sud, Université Paris-Saclay, CNRS, F-92260 Fontenay-aux-Roses, France;
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27
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Hensel N, Schön A, Konen T, Lübben V, Förthmann B, Baron O, Grothe C, Leifheit-Nestler M, Claus P, Haffner D. Fibroblast growth factor 23 signaling in hippocampal cells: impact on neuronal morphology and synaptic density. J Neurochem 2016; 137:756-69. [PMID: 26896818 DOI: 10.1111/jnc.13585] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/18/2016] [Accepted: 02/09/2016] [Indexed: 12/16/2022]
Abstract
Endocrine fibroblast growth factor 23 (FGF23) is predominantly secreted by osteocytes and facilitates renal phosphate excretion. However, FGF23 is also present in cerebrospinal fluid. In chronic kidney disease, FGF23 serum levels are excessively elevated and associated with learning and memory deficits. Structural plasticity of the hippocampus such as formation of new synapses or an altered dendritic arborization comprises a cellular and morphological correlate of memory formation. Therefore, we hypothesize that FGF23 alters hippocampal neuron morphology and synapses. To address this, we prepared primary murine hippocampal cultures and incubated them with recombinant FGF23 alone or together with a soluble isoform of its co-receptor α-Klotho. Neuronal expression of a fluorescent reporter allowed for a detailed evaluation of the neuronal morphology by Sholl analysis. Additionally, we evaluated synaptic density, identified by stainings, for synaptic markers. We show an enhanced number of primary neurites combined with a reduced arborization, resulting in a less complex morphology of neurons treated with FGF23. Moreover, FGF23 enhances the synaptic density in a FGF-receptor (FGF-R) dependent manner. Finally, we addressed the corresponding signaling events downstream of FGF-R employing a combination of western blots and quantitative immunofluorescence. Interestingly, FGF23 induces phospholipase Cγ activity in primary hippocampal neurons. Co-application of soluble α-Klotho leads to activation of the Akt-pathway and modifies FGF23-impact on neuronal morphology and synaptic density. Compared with other FGFs, this alternative signaling pattern is a possible reason for differential effects of FGF23 on hippocampal neurons and may thereby contribute to learning and memory deficits in chronic kidney disease patients. In this study, we show that fibroblast growth factor 23 inhibits neuronal ramification and enhances the synaptic density in primary hippocampal cultures accompanied by phospholipase Cγ-activation. Co-application of the co-receptor α-Klotho leads to an Akt-activation and further modifies neuronal morphology and number of synapses. Those effects provide a mechanistic basis for memory deficits in patients suffering from chronic kidney disease (CKD) characterized by excessively elevated FGF23 levels as well as memory deficits.
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Affiliation(s)
- Niko Hensel
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
| | - Anne Schön
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Timo Konen
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
| | - Verena Lübben
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany.,Center of Systems Neuroscience (ZSN) Hannover, Hannover, Germany
| | | | - Olga Baron
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany
| | - Claudia Grothe
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany.,Center of Systems Neuroscience (ZSN) Hannover, Hannover, Germany
| | - Maren Leifheit-Nestler
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Peter Claus
- Institute of Neuroanatomy, Hannover Medical School, Hannover, Germany.,Center of Systems Neuroscience (ZSN) Hannover, Hannover, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
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28
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Oliveira LMA, Falomir-Lockhart LJ, Botelho MG, Lin KH, Wales P, Koch JC, Gerhardt E, Taschenberger H, Outeiro TF, Lingor P, Schüle B, Arndt-Jovin DJ, Jovin TM. Elevated α-synuclein caused by SNCA gene triplication impairs neuronal differentiation and maturation in Parkinson's patient-derived induced pluripotent stem cells. Cell Death Dis 2015; 6:e1994. [PMID: 26610207 PMCID: PMC4670926 DOI: 10.1038/cddis.2015.318] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 09/23/2015] [Indexed: 12/20/2022]
Abstract
We have assessed the impact of α-synuclein overexpression on the differentiation potential and phenotypic signatures of two neural-committed induced pluripotent stem cell lines derived from a Parkinson's disease patient with a triplication of the human SNCA genomic locus. In parallel, comparative studies were performed on two control lines derived from healthy individuals and lines generated from the patient iPS-derived neuroprogenitor lines infected with a lentivirus incorporating a small hairpin RNA to knock down the SNCA mRNA. The SNCA triplication lines exhibited a reduced capacity to differentiate into dopaminergic or GABAergic neurons and decreased neurite outgrowth and lower neuronal activity compared with control cultures. This delayed maturation phenotype was confirmed by gene expression profiling, which revealed a significant reduction in mRNA for genes implicated in neuronal differentiation such as delta-like homolog 1 (DLK1), gamma-aminobutyric acid type B receptor subunit 2 (GABABR2), nuclear receptor related 1 protein (NURR1), G-protein-regulated inward-rectifier potassium channel 2 (GIRK-2) and tyrosine hydroxylase (TH). The differentiated patient cells also demonstrated increased autophagic flux when stressed with chloroquine. We conclude that a two-fold overexpression of α-synuclein caused by a triplication of the SNCA gene is sufficient to impair the differentiation of neuronal progenitor cells, a finding with implications for adult neurogenesis and Parkinson's disease progression, particularly in the context of bioenergetic dysfunction.
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Affiliation(s)
- L M A Oliveira
- Laboratory of Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - L J Falomir-Lockhart
- Laboratory of Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - M G Botelho
- Laboratory of Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - K-H Lin
- Group of Membrane Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - P Wales
- Department of Neurodegeneration and Restorative Research, University Medical Center Göttingen, Waldweg 33, Göttingen, Germany
| | - J C Koch
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, Göttingen, Germany
| | - E Gerhardt
- Department of Neurodegeneration and Restorative Research, University Medical Center Göttingen, Waldweg 33, Göttingen, Germany
| | - H Taschenberger
- Group of Membrane Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
- DFG-Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - T F Outeiro
- Department of Neurodegeneration and Restorative Research, University Medical Center Göttingen, Waldweg 33, Göttingen, Germany
- DFG-Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - P Lingor
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, Göttingen, Germany
- DFG-Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - B Schüle
- The Parkinson's Institute, 675 Almanor Ave., Sunnyvale, CA, USA
| | - D J Arndt-Jovin
- Laboratory of Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - T M Jovin
- Laboratory of Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
- Laboratory of Cellular Dynamics, Max Planck Institute for Biophysical Chemistry, Am FaÃberg 11, Göttingen 37077, Germany. Tel: +49 551 201 1381; Fax: +49 551 201 1467; E-mail:
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29
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Alpha-Synuclein affects neurite morphology, autophagy, vesicle transport and axonal degeneration in CNS neurons. Cell Death Dis 2015; 6:e1811. [PMID: 26158517 PMCID: PMC4650722 DOI: 10.1038/cddis.2015.169] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 05/14/2015] [Accepted: 05/15/2015] [Indexed: 12/23/2022]
Abstract
Many neuropathological and experimental studies suggest that the degeneration of dopaminergic terminals and axons precedes the demise of dopaminergic neurons in the substantia nigra, which finally results in the clinical symptoms of Parkinson disease (PD). The mechanisms underlying this early axonal degeneration are, however, still poorly understood. Here, we examined the effects of overexpression of human wildtype alpha-synuclein (αSyn-WT), a protein associated with PD, and its mutant variants αSyn-A30P and -A53T on neurite morphology and functional parameters in rat primary midbrain neurons (PMN). Moreover, axonal degeneration after overexpression of αSyn-WT and -A30P was analyzed by live imaging in the rat optic nerve in vivo. We found that overexpression of αSyn-WT and of its mutants A30P and A53T impaired neurite outgrowth of PMN and affected neurite branching assessed by Sholl analysis in a variant-dependent manner. Surprisingly, the number of primary neurites per neuron was increased in neurons transfected with αSyn. Axonal vesicle transport was examined by live imaging of PMN co-transfected with EGFP-labeled synaptophysin. Overexpression of all αSyn variants significantly decreased the number of motile vesicles and decelerated vesicle transport compared with control. Macroautophagic flux in PMN was enhanced by αSyn-WT and -A53T but not by αSyn-A30P. Correspondingly, colocalization of αSyn and the autophagy marker LC3 was reduced for αSyn-A30P compared with the other αSyn variants. The number of mitochondria colocalizing with LC3 as a marker for mitophagy did not differ among the groups. In the rat optic nerve, both αSyn-WT and -A30P accelerated kinetics of acute axonal degeneration following crush lesion as analyzed by in vivo live imaging. We conclude that αSyn overexpression impairs neurite outgrowth and augments axonal degeneration, whereas axonal vesicle transport and autophagy are severely altered.
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30
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Mertens P, Blond S, David R, Rigoard P. Anatomy, physiology and neurobiology of the nociception: a focus on low back pain (part A). Neurochirurgie 2014; 61 Suppl 1:S22-34. [PMID: 25441598 DOI: 10.1016/j.neuchi.2014.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/05/2014] [Accepted: 09/21/2014] [Indexed: 12/13/2022]
Abstract
INTRODUCTION The treatment of Failed Back Surgery Syndrome (FBSS) remains a challenge for pain medicine due to the complexity in the interactions between [1] a residual mechanical pain after surgery and, [2] a progressive transition into chronic pain involving central nervous system plasticity and molecular reorganization. The aim of this paper is to provide a fundamental overview of the pain pathway supporting the nociceptive component of the back pain. METHODS Literature searches included an exhaustive review of 643 references and 74 book chapters updated by searching the major electronic databases from 1930 to August 2013. RESULTS Pain input is gathered by the peripheral fibre from the innervated tissue's environment and relayed by two contiguous central axons to the brain, via the spinal cord. At this level, it is possible to characterize physical pain and emotional pain. These are supported by two different pathways, encoding two dimensions of pain perception: In Neo-spino-thalamic pathway, the wide dynamic range neuron system is able to provide the information needed for mapping the "sensory-discriminative" dimension of pain. The second projection system (Paleo-spino-thalamic pathway) also involves the ventromedial thalamus but projects to the amygdala, the insula and the anterior cingulate cortex. These areas are associated with emotionality and affect. CONCLUSION The mechanical component of FBSS cannot be understood unless the functioning of the pain system is known. But ultimately, the highly variable nature of back pain expression among individuals would require a careful pathophysiological dissection of the potential generators of back pain to guide pain management strategies.
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Affiliation(s)
- P Mertens
- Department of Neurosurgery, Lyon University hospital, 69677 Lyon cedex, France; Laboratory of Anatomy, Faculty of Medicine, 69677 Lyon cedex, France
| | - S Blond
- Department of Neurosurgery, Lille University Hospital, 59037 Lille cedex , France
| | - R David
- Service de neurochirurgie, unité rachis et neurostimulation, Poitiers University Hospital, 2, rue de la Milétrie, 86021 Poitiers cedex, France; N(3)Lab: Neuromodulation & Neural Networks, Poitiers University Hospital, Poitiers, France
| | - P Rigoard
- Service de neurochirurgie, unité rachis et neurostimulation, Poitiers University Hospital, 2, rue de la Milétrie, 86021 Poitiers cedex, France; N(3)Lab: Neuromodulation & Neural Networks, Poitiers University Hospital, Poitiers, France; Inserm CIC 802, 86021 Poitiers, France.
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31
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Labate D, Laezza F, Negi P, Ozcan B, Papadakis M. Efficient processing of fluorescence images using directional multiscale representations. MATHEMATICAL MODELLING OF NATURAL PHENOMENA 2014; 9:177-193. [PMID: 28804225 PMCID: PMC5553129 DOI: 10.1051/mmnp/20149512] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recent advances in high-resolution fluorescence microscopy have enabled the systematic study of morphological changes in large populations of cells induced by chemical and genetic perturbations, facilitating the discovery of signaling pathways underlying diseases and the development of new pharmacological treatments. In these studies, though, due to the complexity of the data, quantification and analysis of morphological features are for the vast majority handled manually, slowing significantly data processing and limiting often the information gained to a descriptive level. Thus, there is an urgent need for developing highly efficient automated analysis and processing tools for fluorescent images. In this paper, we present the application of a method based on the shearlet representation for confocal image analysis of neurons. The shearlet representation is a newly emerged method designed to combine multiscale data analysis with superior directional sensitivity, making this approach particularly effective for the representation of objects defined over a wide range of scales and with highly anisotropic features. Here, we apply the shearlet representation to problems of soma detection of neurons in culture and extraction of geometrical features of neuronal processes in brain tissue, and propose it as a new framework for large-scale fluorescent image analysis of biomedical data.
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Affiliation(s)
- D. Labate
- Dept. of Mathematics, University of Houston, Houston, Texas 77204, USA
| | - F. Laezza
- Dept. of Pharmacology and Toxicology, UT Medical Branch, Galveston, TX 77555, USA
| | - P. Negi
- Dept. of Mathematics, University of Houston, Houston, Texas 77204, USA
| | - B. Ozcan
- Dept. of Mathematics, University of Houston, Houston, Texas 77204, USA
| | - M. Papadakis
- Dept. of Mathematics, University of Houston, Houston, Texas 77204, USA
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32
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Cdk5 induces constitutive activation of 5-HT6 receptors to promote neurite growth. Nat Chem Biol 2014; 10:590-7. [DOI: 10.1038/nchembio.1547] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 04/30/2014] [Indexed: 02/07/2023]
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33
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Hopkins AM, Wheeler B, Staii C, Kaplan DL, Atherton TJ. Semi-automatic quantification of neurite fasciculation in high-density neurite images by the neurite directional distribution analysis (NDDA). J Neurosci Methods 2014; 228:100-9. [PMID: 24680908 DOI: 10.1016/j.jneumeth.2014.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 03/12/2014] [Accepted: 03/13/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND Bundling of neurite extensions occur during nerve development and regeneration. Understanding the factors that drive neurite bundling is important for designing biomaterials for nerve regeneration toward the innervation target and preventing nociceptive collateral sprouting. High-density neuron cultures including dorsal root ganglia explants are employed for in vitro screening of biomaterials designed to control directional outgrowth. Although some semi-automated image processing methods exist for quantification of neurite outgrowth, methods to quantify axonal fasciculation in terms of direction of neurite outgrowth are lacking. NEW METHOD This work presents a semi-automated program to analyze micrographs of high-density neurites; the program aims to quantify axonal fasciculation by determining the orientational distribution function of the tangent vectors of the neurites and calculating its Fourier series coefficients ('c' values). RESULTS We found that neurite directional distribution analysis (NDDA) of fasciculated neurites yielded 'c' values of ≥∼0.25 whereas branched outgrowth led to statistically significant lesser values of <∼0.2. The 'c' values correlated directly to the width of neurite bundles and indirectly to the number of branching points. COMPARISON WITH EXISTING METHODS Information about the directional distribution of outgrowth is lost in simple counting methods or achieved laboriously through manual analysis. The NDDA supplements previous quantitative analyses of axonal bundling using a vector-based approach that captures new information about the directionality of outgrowth. CONCLUSION The NDDA is a valuable addition to open source image processing tools available to biomedical researchers offering a robust, precise approach to quantification of imaged features important in tissue development, disease, and repair.
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Affiliation(s)
- Amy M Hopkins
- Department of Biomedical Engineering, Tufts University Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA.
| | - Brandon Wheeler
- Department of Biomedical Engineering, Tufts University Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA.
| | - Cristian Staii
- Department of Physics and Astronomy, and Center for Nanoscopic Physics, Tufts University Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA.
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA.
| | - Timothy J Atherton
- Department of Physics and Astronomy, and Center for Nanoscopic Physics, Tufts University Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA.
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Sholl analysis: A quantitative comparison of semi-automated methods. J Neurosci Methods 2014; 225:65-70. [DOI: 10.1016/j.jneumeth.2014.01.017] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 01/15/2014] [Accepted: 01/17/2014] [Indexed: 01/03/2023]
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Garcia-Segura LM, Perez-Marquez J. A new mathematical function to evaluate neuronal morphology using the Sholl analysis. J Neurosci Methods 2014; 226:103-109. [PMID: 24503022 DOI: 10.1016/j.jneumeth.2014.01.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 01/15/2014] [Accepted: 01/16/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND The Sholl analysis is a morphometric method that evaluates the neurite architecture of neurons by drawing a series of concentric circles around the cell soma. Based on the Sholl analysis, one mathematical method that gives a measure of the neurite arborization is the Schoenen ramification index (SRI): the ratio between the maximum number of the intersections of the neurites with the circles and the number of the primary neurites. A different method is the quantification of the number of bifurcations of the neurites (BN). NEW METHOD In this study we proposed a new mathematical function to quantify neurite morphology that we named the branching index (BI). The BI compares the difference in the number of intersections made in pairs of circles relative to the distance from the neuronal soma. To facilitate the morphometric analysis, we developed informatics software named CellTarget that obtains the quantitative variables of the Sholl analysis and neurite branching. RESULTS Using that bioinformatics application we compared the BI, the SRI and BN values in neuronal models and in neuronal hippocampal cultures treated or untreated with the androgen dihydrotestosterone, which is known to induce neurite branching. COMPARISON WITH EXISTING METHODS Although the SRI and the BN provided quantitative information of the degree of neurite morphology, it produced similar values in neurons that ramify very differently. By contrast, these differences were discriminated using the BI. CONCLUSIONS The BI is a useful parameter to discriminate among different neuronal morphologies.
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Affiliation(s)
| | - Julio Perez-Marquez
- Departamento de Biomedicina y Biotecnología, Universidad Alcalá de Henares, 28871 Madrid, Spain.
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Szucs P, Luz LL, Pinho R, Aguiar P, Antal Z, Tiong SYX, Todd AJ, Safronov BV. Axon diversity of lamina I local-circuit neurons in the lumbar spinal cord. J Comp Neurol 2014; 521:2719-41. [PMID: 23386329 PMCID: PMC3738926 DOI: 10.1002/cne.23311] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 12/26/2012] [Accepted: 01/18/2012] [Indexed: 01/21/2023]
Abstract
Spinal lamina I is a key area for relaying and integrating information from nociceptive primary afferents with various other sources of inputs. Although lamina I projection neurons have been intensively studied, much less attention has been given to local-circuit neurons (LCNs), which form the majority of the lamina I neuronal population. In this work the infrared light-emitting diode oblique illumination technique was used to visualize and label LCNs, allowing reconstruction and analysis of their dendritic and extensive axonal trees. We show that the majority of lamina I neurons with locally branching axons fall into the multipolar (with ventrally protruding dendrites) and flattened (dendrites limited to lamina I) somatodendritic categories. Analysis of their axons revealed that the initial myelinated part gives rise to several unmyelinated small-diameter branches that have a high number of densely packed, large varicosities and an extensive rostrocaudal (two or three segments), mediolateral, and dorsoventral (reaching laminae III-IV) distribution. The extent of the axon and the occasional presence of long, solitary branches suggest that LCNs may also form short and long propriospinal connections. We also found that the distribution of axon varicosities and terminal field locations show substantial heterogeneity and that a substantial portion of LCNs is inhibitory. Our observations indicate that LCNs of lamina I form intersegmental as well as interlaminar connections and may govern large numbers of neurons, providing anatomical substrate for rostrocaudal "processing units" in the dorsal horn.
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Affiliation(s)
- Peter Szucs
- Spinal Neuronal Networks Group, Institute of Molecular and Cell Biology-IBMC, University of Porto, 4150-180 Porto, Portugal.
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Sun D, Qu J, Jakobs TC. Reversible reactivity by optic nerve astrocytes. Glia 2013; 61:1218-35. [PMID: 23650091 DOI: 10.1002/glia.22507] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 03/14/2013] [Indexed: 12/25/2022]
Abstract
Reactive astrocytes are typically studied in models that cause irreversible mechanical damage to axons, neuronal cell bodies, and glia. Here, we evaluated the response of astrocytes in the optic nerve head to a subtle injury induced by a brief, mild elevation of the intraocular pressure. Astrocytes demonstrated reactive remodeling that peaked at three days, showing hypertrophy, process retraction, and simplification of their shape. This was not accompanied by any significant changes in the gene expression profile. At no time was there discernible damage to the optic axons, as evidenced by electron microscopy and normal anterograde and retrograde transport. Remarkably, the morphological remodeling was reversible. These findings underscore the plastic nature of reactivity. They show that reactivity can resolve fully if the insult is removed, and suggest that reactivity per se is not necessarily deleterious to axons. This reaction may represent very early events in the sequence that eventually leads to glial scarring.
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Affiliation(s)
- Daniel Sun
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
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A novel population of cholinergic neurons in the macaque spinal dorsal horn of potential clinical relevance for pain therapy. J Neurosci 2013; 33:3727-37. [PMID: 23447584 DOI: 10.1523/jneurosci.3954-12.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Endogenous acetylcholine (ACh) is a well-known modulator of nociceptive transmission in the spinal cord of rodents. It arises mainly from a sparse population of cholinergic interneurons located in the dorsal horn of the spinal cord. This population was thought to be absent from the spinal cord of monkey, what might suggest that spinal ACh would not be a relevant clinical target for pain therapy. In humans, however, pain responses can be modulated by spinal ACh, as evidenced by the increasingly used analgesic procedure (for postoperative and labor patients) consisting of the epidural injection of the acetylcholinesterase inhibitor neostigmine. The source and target of this ACh remain yet to be elucidated. In this study, we used an immunolabeling for choline acetyltransferase to demonstrate, for the first time, the presence of a plexus of cholinergic fibers in laminae II-III of the dorsal horn of the macaque monkey. Moreover, we show the presence of numerous cholinergic cell bodies within the same laminae and compared their density and morphological properties with those previously described in rodents. An electron microscopy analysis demonstrates that cholinergic boutons are presynaptic to dorsal horn neurons as well as to the terminals of sensory primary afferents, suggesting that they are likely to modulate incoming somatosensory information. Our data suggest that this newly identified dorsal horn cholinergic system in monkeys is the source of the ACh involved in the analgesic effects of epidural neostigmine and could be more specifically targeted for novel therapeutic strategies for pain management in humans.
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Analysis of morphological changes as a key method in studying psychiatric animal models. Cell Tissue Res 2013; 354:41-50. [PMID: 23334194 PMCID: PMC3785701 DOI: 10.1007/s00441-012-1547-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 12/05/2012] [Indexed: 12/26/2022]
Abstract
A major interest in the analysis of animal models of psychiatric diseases is their underlying cellular pathology and to gain information regarding whether pharmacological treatments, genetic differences or an altered environment exert an impact upon the brain morphology or on the morphology or activity of single neurones. In this review, several key methods will be introduced that allow the analysis of morphological changes that are frequently observed in psychiatric animal models. An overview of the techniques that enable dendritic arborisation, alterations in dendritic spines and changes in fibre densities to be analysed are described. Moreover, methods for the analysis of adult neurogenesis and neurodegeneration and for the analysis of neuronal activity in fixed brain tissue are described. An important step during the analysis of morphological changes is the estimation of the number of stained cells. Since conventional cell counting methods have several limitations, two different approaches that permit an estimate of the number of stained cells within three-dimensional tissue are also discussed.
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40
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Morrison HW, Filosa JA. A quantitative spatiotemporal analysis of microglia morphology during ischemic stroke and reperfusion. J Neuroinflammation 2013; 10:4. [PMID: 23311642 PMCID: PMC3570327 DOI: 10.1186/1742-2094-10-4] [Citation(s) in RCA: 371] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 12/24/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Microglia cells continuously survey the healthy brain in a ramified morphology and, in response to injury, undergo progressive morphological and functional changes that encompass microglia activation. Although ideally positioned for immediate response to ischemic stroke (IS) and reperfusion, their progressive morphological transformation into activated cells has not been quantified. In addition, it is not well understood if diverse microglia morphologies correlate to diverse microglia functions. As such, the dichotomous nature of these cells continues to confound our understanding of microglia-mediated injury after IS and reperfusion. The purpose of this study was to quantitatively characterize the spatiotemporal pattern of microglia morphology during the evolution of cerebral injury after IS and reperfusion. METHODS Male C57Bl/6 mice were subjected to focal cerebral ischemia and periods of reperfusion (0, 8 and 24 h). The microglia process length/cell and number of endpoints/cell was quantified from immunofluorescent confocal images of brain regions using a skeleton analysis method developed for this study. Live cell morphology and process activity were measured from movies acquired in acute brain slices from GFP-CX3CR1 transgenic mice after IS and 24-h reperfusion. Regional CD11b and iNOS expressions were measured from confocal images and Western blot, respectively, to assess microglia proinflammatory function. RESULTS Quantitative analysis reveals a significant spatiotemporal relationship between microglia morphology and evolving cerebral injury in the ipsilateral hemisphere after IS and reperfusion. Microglia were both hyper- and de-ramified in striatal and cortical brain regions (respectively) after 60 min of focal cerebral ischemia. However, a de-ramified morphology was prominent when ischemia was coupled to reperfusion. Live microglia were de-ramified, and, in addition, process activity was severely blunted proximal to the necrotic core after IS and 24 h of reperfusion. CD11b expression, but not iNOS expression, was increased in regions of hyper- and de-ramified microglia during the course of ischemic stroke and 24 h of reperfusion. CONCLUSIONS Our findings illustrate that microglia activation after stroke includes both increased and decreased cell ramification. Importantly, quantitative analyses of microglial morphology and activity are feasible and, in future studies, would assist in the comprehensive identification and stratification of their dichotomous contribution toward cerebral injury and recovery during IS and reperfusion.
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Zeilhofer HU, Wildner H, Yévenes GE. Fast synaptic inhibition in spinal sensory processing and pain control. Physiol Rev 2012; 92:193-235. [PMID: 22298656 DOI: 10.1152/physrev.00043.2010] [Citation(s) in RCA: 262] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The two amino acids GABA and glycine mediate fast inhibitory neurotransmission in different CNS areas and serve pivotal roles in the spinal sensory processing. Under healthy conditions, they limit the excitability of spinal terminals of primary sensory nerve fibers and of intrinsic dorsal horn neurons through pre- and postsynaptic mechanisms, and thereby facilitate the spatial and temporal discrimination of sensory stimuli. Removal of fast inhibition not only reduces the fidelity of normal sensory processing but also provokes symptoms very much reminiscent of pathological and chronic pain syndromes. This review summarizes our knowledge of the molecular bases of spinal inhibitory neurotransmission and its organization in dorsal horn sensory circuits. Particular emphasis is placed on the role and mechanisms of spinal inhibitory malfunction in inflammatory and neuropathic chronic pain syndromes.
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Bulk loading of calcium indicator dyes to study astrocyte physiology: key limitations and improvements using morphological maps. J Neurosci 2011; 31:9353-8. [PMID: 21697385 DOI: 10.1523/jneurosci.0127-11.2011] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Calcium signaling has been studied in astrocyte cell bodies using bulk loading of calcium indicator dyes, and astrocytes are known to display intracellular calcium transients. An assumption in recent data on the neuronal impact of somatic astrocyte calcium transients has been that bulk loading reflects signaling in relevant astrocyte compartments such as processes. We assessed bulk loading using Sholl analysis (Sholl, 1953) of astrocytes loaded with common calcium indicator dyes and compared these data with Sholl analysis of astrocyte morphology. In the CA1 region of the hippocampus from rats, we found that bulk loading of calcium indicator dyes only reports on calcium signals within the soma and in the most proximal processes, leaving ∼90% of the area of an astrocyte and its extensive processes unsampled. By using morphological reconstructions as "maps" after the imaging session, we present simple procedures that remedy these shortfalls and permit reliable detection of calcium transients in distal astrocyte processes. The data thus reveal limitations in the interpretation of astrocyte calcium imaging data gathered with bulk loading and provide refinements to minimize these shortcomings.
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Wu SX, Wang W, Li H, Wang YY, Feng YP, Li YQ. The synaptic connectivity that underlies the noxious transmission and modulation within the superficial dorsal horn of the spinal cord. Prog Neurobiol 2010; 91:38-54. [DOI: 10.1016/j.pneurobio.2010.01.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 12/10/2009] [Accepted: 01/14/2010] [Indexed: 01/27/2023]
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Milosević NT, Ristanović D, Marić DL, Gudović R, Krstonosić B. Quantitative analysis of dendritic branching pattern of large neurons in human cerebellum. VOJNOSANIT PREGL 2010; 67:712-6. [DOI: 10.2298/vsp1009712m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Background/Aim. Dentate nucleus (nucleus dentatus) is the most distant of the cerebellar nuclei and the major system for information transfer in the cerebellum. So far, dendritic branches of four different kinds of large neurons of dentate nucleus, have been considered mainly qualitatively with no quantification of their morphological features. The aim of the study was to test the qualitative hypothesis that the human dentate nucleus is composed of various types of the large neurons by quantitative analysis of their dendritic branching patterns. Methods. Series of horizontal sections of the dentate nuclei were taken from 15 adult human brains, free of diagnosed neurological disorders. The 189 Golgi-impregnated images of large neurons were recorded by a digital camera connected to a light microscope. Dendritic branching patterns of digitized neuronal images were analyzed by modified Sholl and fractal analyses. Results. The number of intersections (Nm), critical radius (rc) and fractal dimension (D) of dendritic branching pattern for four types of the large neurons were calculated, statistically evaluated and analyzed. The results show that there is a significant difference between four neuronal types in one morphometric parameter at least. Conclusion. The present study is the first attempt to analyze quantitatively the dendritic branching pattern of neurons from the dentate nucleus in the human. The hypothesis that the four types of the large neurons exist in this part of human cerebellum is successfully supported.
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Affiliation(s)
- Nebojsa T Milosević
- Univerzitet u Beogradu, Medicinski fakultet, Institut za biofiziku, Beograd, Srbija.
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Ristanović D, Milosević NT, Stefanović IB, Marić D, Popov I. Cell image area as a tool for neuronal classification. J Neurosci Methods 2009; 182:272-8. [PMID: 19524614 DOI: 10.1016/j.jneumeth.2009.06.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 05/18/2009] [Accepted: 06/03/2009] [Indexed: 11/15/2022]
Abstract
The measurement of the area of a shapeless plane region is one of the basic problems in traditional calculus. In order to calculate the 'true' area of such a region, we have superimposed a net of identical squares on this region, counted the squares containing at least one point of the region, and calculated the sum of the areas of said squares. This sum represents an approximation of the region's area. By mathematical modelling and computational techniques we have investigated the law governing the decrease of these areas with the decrease of the length of the square's side. In theory, the prediction of the 'true' area could then be performed if the side of the net's squares tend to zero. Of course, the accuracy of the calculated area strongly depends on the computational potential and the statistical possibilities. Several morphometric parameters are currently in use for the quantitative analysis of the morphology of neuronal cell images. The cell image area has not yet been used and evaluated as a classification parameter - but it has the potential to be chosen over some other alternatives due to the high mathematical accuracy at which it is defined. By adopting mathematical modelling and computational techniques we show that this parameter can lead to successful distinction between 2 types of morphologically very similar cells (large boundary neuron and large asymmetrical neuron) in the dentate nucleus of the rhesus monkey (Macaca mulatta), while some other parameters failed to achieve positive results.
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Affiliation(s)
- Dusan Ristanović
- Department of Biophysics, School of Medicine, University of Belgrade, Visegradska 26, 11000 Belgrade, Serbia.
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Ristanović D, Milosević NT, Jelinek HF, Stefanović IB. Mathematical modelling of neuronal dendritic branching patterns in two dimensions: application to retinal ganglion cells in the cat and rat. BIOLOGICAL CYBERNETICS 2009; 100:97-108. [PMID: 18985379 DOI: 10.1007/s00422-008-0271-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 10/03/2008] [Indexed: 05/27/2023]
Abstract
Sholl's analysis has been used for about 50 years to study neuron branching characteristics based on a linear, semi-log or log-log method. Using the linear two- dimensional Sholl's method, we call attention to a relationship between the number of intersections of neuronal dendrites with a circle and the numbers of branching points and terminal tips encompassed by the circle, with respect to the circle radius. For that purpose, we present a mathematical model, which incorporates a supposition that the number of dendritic intersections with a circle can be resolved into two components: the number of branching points and the number of terminal tips within the annulus of two adjoining circles. The numbers of intersections and last two sets of data are also presented as cumulative frequency plots and analysed using a logistic model (Boltzmann's function). Such approaches give rise to several new morphometric parameters, such as, the critical, maximal and mean values of the numbers of intersections, branching points and terminal tips, as well as the abscissas of the inflection points of the corresponding sigmoid plots, with respect to the radius. We discuss these parameters as an additional tool for further morphological classification schemes of vertebrate retinal ganglion cells. To test the models, we apply them first to three groups of morphologically different cat's retinal ganglion cells (the alpha, gamma and epsilon cells). After that, in order to quantitatively support the classification of the rat's alpha cells into the inner and outer cells, we apply our models to two subgroups of these cells grouped according to their stratification levels in the inner plexiform layer. We show that differences between most of our parameters calculated for these subgroups are statistically significant. We believe that these models have the potential to aid in the classification of biological images.
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Affiliation(s)
- Dusan Ristanović
- Department of Biophysics, School of Medicine, University of Belgrade, 11000 Belgrade, Serbia.
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Sarikcioglu L, Ozsoy U. Bror Rexed (1914–2002). J Neurol 2008; 255:1988-9. [DOI: 10.1007/s00415-008-0927-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Revised: 01/30/2008] [Accepted: 03/05/2008] [Indexed: 11/28/2022]
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Polgár E, Thomson S, Maxwell DJ, Al-Khater K, Todd AJ. A population of large neurons in laminae III and IV of the rat spinal cord that have long dorsal dendrites and lack the neurokinin 1 receptor. Eur J Neurosci 2007; 26:1587-98. [PMID: 17880393 PMCID: PMC2635481 DOI: 10.1111/j.1460-9568.2007.05793.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dorsal horn of the rat spinal cord contains a population of large neurons with cell bodies in laminae III or IV, that express the neurokinin 1 receptor (NK1r) and have long dorsal dendrites that branch extensively within the superficial laminae. In this study, we have identified a separate population of neurons that have similar dendritic morphology, but lack the NK1r. These cells also differ from the NK1r-expressing neurons in that they have significantly fewer contacts from substance P-containing axons and are not retrogradely labelled following injection of tracer into the caudal ventrolateral medulla. We also provide evidence that these cells do not belong to the postsynaptic dorsal column pathway or the spinothalamic tract. It is therefore likely that these cells do not have supraspinal projections. They may provide a route through which information transmitted by C fibres that lack neuropeptides is conveyed to deeper laminae. The present findings demonstrate the need for caution when attempting to classify neurons solely on the basis of somatodendritic morphology.
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Affiliation(s)
- Erika Polgár
- Spinal Cord Group, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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Milosević NT, Ristanović D, Gudović R, Rajković K, Marić D. Application of fractal analysis to neuronal dendritic arborisation patterns of the monkey dentate nucleus. Neurosci Lett 2007; 425:23-7. [PMID: 17723278 DOI: 10.1016/j.neulet.2007.08.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2007] [Revised: 07/12/2007] [Accepted: 08/04/2007] [Indexed: 11/19/2022]
Abstract
The deep nuclei of the cerebellar cortex have not yet received adequate exploratory attention. An exception is represented by the pioneering work of Chan-Palay, published in 1977, on the dentate nucleus morphology. She has classified each individual cell in the dentatus of the monkey into one of six types. Although fractal analysis is presently the most prominent quantitative method for morphometric neuronal studies, no article referring to applications of this method to the analysis of cell types of the dentate nucleus has so far been published. In the present study we apply fractal analysis to this unsolved problem and calculate the fractal dimension for each dendritic arbour of a neuron. We will hereby prove that by application of fractal analysis to the dendritic arbours of these cells whilst ignoring other neuronal attributes allows for clear discrimination of only three cell types.
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Affiliation(s)
- Nebojsa T Milosević
- Department of Biophysics, School of Medicine, University of Belgrade, Belgrade, Serbia.
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50
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Maxwell DJ, Belle MD, Cheunsuang O, Stewart A, Morris R. Morphology of inhibitory and excitatory interneurons in superficial laminae of the rat dorsal horn. J Physiol 2007; 584:521-33. [PMID: 17717012 PMCID: PMC2277171 DOI: 10.1113/jphysiol.2007.140996] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
If we are to stand any chance of understanding the circuitry of the superficial dorsal horn, it is imperative that we can identify which classes of interneuron are excitatory and which are inhibitory. Our aim was to test the hypothesis that there is a correlation between the morphology of an interneuron and its postsynaptic action. We used in vitro slice preparations of the rat spinal cord to characterize and label interneurons in laminae I-III with Neurobiotin. Labelled cells (n = 19) were reconstructed in 3D with Neurolucida and classified according to the scheme proposed by Grudt & Perl (2002). We determined if cells were inhibitory or excitatory by reacting their axon terminals with antibodies to reveal glutamate decrboxylase (for GABAergic cells) or the vesicular glutamate transporter 2 (for glutamatergic cells). All five islet cells retrieved were inhibitory. Of the six vertical (stalked) cells analysed, four were excitatory and, surprisingly, two were inhibitory. It was noted that these inhibitory cells had axonal projections confined to lamina II whereas excitatory vertical cells projected to lamina I and II. Of the remaining neurons, three were radial cells (2 inhibitory, 1 excitatory), two were antennae cells (1 inhibitory, 1 excitatory), one was an inhibitory central cell and the remaining two were unclassifiable excitatory cells. Our hypothesis appears to be correct only for islet cells. Other classes of cells have mixed actions, and in the case of vertical cells, the axonal projection appears to be a more important determinant of postsynaptic action.
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Affiliation(s)
- David J Maxwell
- Spinal Cord Group, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
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