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Dang R, Liu A, Zhou Y, Li X, Wu M, Cao K, Meng Y, Zhang H, Gan G, Xie W, Jia Z. Astrocytic neuroligin 3 regulates social memory and synaptic plasticity through adenosine signaling in male mice. Nat Commun 2024; 15:8639. [PMID: 39366972 PMCID: PMC11452673 DOI: 10.1038/s41467-024-52974-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 09/27/2024] [Indexed: 10/06/2024] Open
Abstract
Social memory impairment is a key symptom of many brain disorders, but its underlying mechanisms remain unclear. Neuroligins (NLGs) are a family of cell adhesion molecules essential for synapse development and function and their dysfunctions are linked to neurodevelopmental and neuropsychiatric disorders, including autism and schizophrenia. Although NLGs are extensively studied in neurons, their role in glial cells is poorly understood. Here we show that astrocytic deletion of NLG3 in the ventral hippocampus of adult male mice impairs social memory, attenuates astrocytic Ca2+ signals, enhances the expression of EAAT2 and prevents long-term potentiation, and these impairments are rescued by increasing astrocyte activity, reducing EAAT2 function or enhancing adenosine/A2a receptor signaling. This study has revealed an important role of NLG3 in astrocyte function, glutamate homeostasis and social memory and identified the glutamate transporter and adenosine signaling pathway as potential therapeutic strategies to treat brain disorders.
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Affiliation(s)
- Rui Dang
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, The School of Life Science and Technology, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
- Institute for Brain and Intelligence, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
- Shenzhen Research Institute, Southeast University, 19 Gaoxin South 4th Road, Shenzhen, 518063, China
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08854, USA
| | - An Liu
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, The School of Life Science and Technology, Southeast University, 2 Sipailou Road, Nanjing, 210096, China.
- Institute for Brain and Intelligence, Southeast University, 2 Sipailou Road, Nanjing, 210096, China.
- Shenzhen Research Institute, Southeast University, 19 Gaoxin South 4th Road, Shenzhen, 518063, China.
- Neurosciences & Mental Health, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada.
| | - Yu Zhou
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, The School of Life Science and Technology, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
- Institute for Brain and Intelligence, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
- Shenzhen Research Institute, Southeast University, 19 Gaoxin South 4th Road, Shenzhen, 518063, China
| | - Xingcan Li
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, The School of Life Science and Technology, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
- Institute for Brain and Intelligence, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
| | - Miao Wu
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, The School of Life Science and Technology, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
- Institute for Brain and Intelligence, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
| | - Kun Cao
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, The School of Life Science and Technology, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
- Institute for Brain and Intelligence, Southeast University, 2 Sipailou Road, Nanjing, 210096, China
| | - Yanghong Meng
- Neurosciences & Mental Health, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Haiwang Zhang
- Neurosciences & Mental Health, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Guangming Gan
- School of Medicine, Southeast University, Nanjing, Jiangsu, 210009, China
| | - Wei Xie
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, The School of Life Science and Technology, Southeast University, 2 Sipailou Road, Nanjing, 210096, China.
- Institute for Brain and Intelligence, Southeast University, 2 Sipailou Road, Nanjing, 210096, China.
- Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, 2 Sipailou Road, Nanjing, 210096, China.
| | - Zhengping Jia
- Neurosciences & Mental Health, The Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada.
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada.
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Gebicke-Haerter PJ. The computational power of the human brain. Front Cell Neurosci 2023; 17:1220030. [PMID: 37608987 PMCID: PMC10441807 DOI: 10.3389/fncel.2023.1220030] [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: 05/19/2023] [Accepted: 07/05/2023] [Indexed: 08/24/2023] Open
Abstract
At the end of the 20th century, analog systems in computer science have been widely replaced by digital systems due to their higher computing power. Nevertheless, the question keeps being intriguing until now: is the brain analog or digital? Initially, the latter has been favored, considering it as a Turing machine that works like a digital computer. However, more recently, digital and analog processes have been combined to implant human behavior in robots, endowing them with artificial intelligence (AI). Therefore, we think it is timely to compare mathematical models with the biology of computation in the brain. To this end, digital and analog processes clearly identified in cellular and molecular interactions in the Central Nervous System are highlighted. But above that, we try to pinpoint reasons distinguishing in silico computation from salient features of biological computation. First, genuinely analog information processing has been observed in electrical synapses and through gap junctions, the latter both in neurons and astrocytes. Apparently opposed to that, neuronal action potentials (APs) or spikes represent clearly digital events, like the yes/no or 1/0 of a Turing machine. However, spikes are rarely uniform, but can vary in amplitude and widths, which has significant, differential effects on transmitter release at the presynaptic terminal, where notwithstanding the quantal (vesicular) release itself is digital. Conversely, at the dendritic site of the postsynaptic neuron, there are numerous analog events of computation. Moreover, synaptic transmission of information is not only neuronal, but heavily influenced by astrocytes tightly ensheathing the majority of synapses in brain (tripartite synapse). At least at this point, LTP and LTD modifying synaptic plasticity and believed to induce short and long-term memory processes including consolidation (equivalent to RAM and ROM in electronic devices) have to be discussed. The present knowledge of how the brain stores and retrieves memories includes a variety of options (e.g., neuronal network oscillations, engram cells, astrocytic syncytium). Also epigenetic features play crucial roles in memory formation and its consolidation, which necessarily guides to molecular events like gene transcription and translation. In conclusion, brain computation is not only digital or analog, or a combination of both, but encompasses features in parallel, and of higher orders of complexity.
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Affiliation(s)
- Peter J. Gebicke-Haerter
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine, University of Heidelberg, Mannheim, Germany
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Calvin-Cejudo L, Martin F, Mendez LR, Coya R, Castañeda-Sampedro A, Gomez-Diaz C, Alcorta E. Neuron-glia interaction at the receptor level affects olfactory perception in adult Drosophila. iScience 2022; 26:105837. [PMID: 36624835 PMCID: PMC9823236 DOI: 10.1016/j.isci.2022.105837] [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: 08/09/2022] [Revised: 11/17/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022] Open
Abstract
Some types of glia play an active role in neuronal signaling by modifying their activity although little is known about their role in sensory information signaling at the receptor level. In this research, we report a functional role for the glia that surround the soma of the olfactory receptor neurons (OSNs) in adult Drosophila. Specific genetic modifications have been targeted to this cell type to obtain live individuals who are tested for olfactory preference and display changes both increasing and reducing sensitivity. A closer look at the antenna by Ca2+ imaging shows that odor activates the OSNs, which subsequently produce an opposite and smaller effect in the glia that partially counterbalances neuronal activation. Therefore, these glia may play a dual role in preventing excessive activation of the OSNs at high odorant concentrations and tuning the chemosensory window for the individual according to the network structure in the receptor organ.
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Affiliation(s)
- Laura Calvin-Cejudo
- Group of Neurobiology of the Sensory Systems (NEUROSEN), Department of Functional Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Fernando Martin
- Group of Neurobiology of the Sensory Systems (NEUROSEN), Department of Functional Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Luis R. Mendez
- Group of Neurobiology of the Sensory Systems (NEUROSEN), Department of Functional Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Ruth Coya
- Group of Neurobiology of the Sensory Systems (NEUROSEN), Department of Functional Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Ana Castañeda-Sampedro
- Group of Neurobiology of the Sensory Systems (NEUROSEN), Department of Functional Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Carolina Gomez-Diaz
- Group of Neurobiology of the Sensory Systems (NEUROSEN), Department of Functional Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
| | - Esther Alcorta
- Group of Neurobiology of the Sensory Systems (NEUROSEN), Department of Functional Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Corresponding author
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Article Type: Original Article Title: Linalyl Acetate Ameliorates Mechanical Hyperalgesia Through Suppressing Inflammation by TSLP/IL-33 Signaling. Neurochem Res 2022; 47:3805-3816. [DOI: 10.1007/s11064-022-03763-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 09/15/2022] [Accepted: 09/20/2022] [Indexed: 10/31/2022]
Abstract
AbstractNeuropathic pain is a debilitating chronic disorder, significantly causing personal and social burdens, in which activated neuroinflammation is one major contributor. Thymic stromal lymphopoietin (TSLP) and interleukin (IL)-33 is important for chronic inflammation. Linalyl acetate (LA) is main component of lavender oil with an anti-inflammatory property through TSLP signaling. The aim of the study is to investigate how LA regulates mechanical hyperalgesia after sciatic nerve injury (SNI). Adult Sprague-Dawley male rats were separated into 3 groups: control group, SNI group and SNI with LA group. LA was administrated intraperitoneally one day before SNI. Pain behavior test was evaluated through calibration forceps testing. Ipsilateral sciatic nerves (SNs), dorsal root ganglions (DRGs) and spinal cord were collected for immunofluorescence staining and Western blotting analyses. SNI rats were more sensitive to hyperalgesia response to mechanical stimulus since operation, which was accompanied by spinal cord glial cells reactions and DRG neuro-glial interaction. LA could relieve the pain sensation, proinflammatory cytokines and decrease the expression of TSLP/TSLPR complex. Also, LA could reduce inflammation through reducing IL-33 signaling. This study is the first to indicate that LA can modulate pain through TSLP/TSLPR and IL-33 signaling after nerve injury.
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Schmithorst VJ, Adams PS, Badaly D, Lee VK, Wallace J, Beluk N, Votava-Smith JK, Weinberg JG, Beers SR, Detterich J, Wood JC, Lo CW, Panigrahy A. Impaired Neurovascular Function Underlies Poor Neurocognitive Outcomes and Is Associated with Nitric Oxide Bioavailability in Congenital Heart Disease. Metabolites 2022; 12:metabo12090882. [PMID: 36144286 PMCID: PMC9504090 DOI: 10.3390/metabo12090882] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 12/03/2022] Open
Abstract
We use a non-invasive MRI proxy of neurovascular function (pnvf) to assess the ability of the vasculature to supply baseline metabolic demand, to compare pediatric and young adult congenital heart disease (CHD) patients to normal referents and relate the proxy to neurocognitive outcomes and nitric oxide bioavailability. In a prospective single-center study, resting-state blood-oxygen-level-dependent (BOLD) and arterial spin labeling (ASL) MRI scans were successfully obtained from 24 CHD patients (age = 15.4 ± 4.06 years) and 63 normal referents (age = 14.1 ± 3.49) years. Pnvf was computed on a voxelwise basis as the negative of the ratio of functional connectivity strength (FCS) estimated from the resting-state BOLD acquisition to regional cerebral blood flow (rCBF) as estimated from the ASL acquisition. Pnvf was used to predict end-tidal CO2 (PETCO2) levels and compared to those estimated from the BOLD data. Nitric oxide availability was obtained via nasal measurements (nNO). Pnvf was compared on a voxelwise basis between CHD patients and normal referents and correlated with nitric oxide availability and neurocognitive outcomes as assessed via the NIH Toolbox. Pnvf was shown as highly predictive of PETCO2 using theoretical modeling. Pnvf was found to be significantly reduced in CHD patients in default mode network (DMN, comprising the ventromedial prefrontal cortex and posterior cingulate/precuneus), salience network (SN, comprising the insula and dorsal anterior cingulate), and central executive network (CEN, comprising posterior parietal and dorsolateral prefrontal cortex) regions with similar findings noted in single cardiac ventricle patients. Positive correlations of Pnvf in these brain regions, as well as the hippocampus, were found with neurocognitive outcomes. Similarly, positive correlations between Pnvf and nitric oxide availability were found in frontal DMN and CEN regions, with particularly strong correlations in subcortical regions (putamen). Reduced Pnvf in CHD patients was found to be mediated by nNO. Mediation analyses further supported that reduced Pnvf in these regions underlies worse neurocognitive outcome in CHD patients and is associated with nitric oxide bioavailability. Impaired neuro-vascular function, which may be non-invasively estimated via combined arterial-spin label and BOLD MR imaging, is a nitric oxide bioavailability dependent factor implicated in adverse neurocognitive outcomes in pediatric and young adult CHD.
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Affiliation(s)
| | - Phillip S. Adams
- Department of Pediatric Anesthesiology, UPMC Children’s Hospital, Pittsburgh, PA 15224, USA
| | - Daryaneh Badaly
- Learning and Development Center, Child Mind Institute, New York, NY 10022, USA
| | - Vincent K. Lee
- Department of Pediatric Radiology, UPMC Children’s Hospital, Pittsburgh, PA 15224, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Julia Wallace
- Department of Pediatric Radiology, UPMC Children’s Hospital, Pittsburgh, PA 15224, USA
| | - Nancy Beluk
- Department of Pediatric Radiology, UPMC Children’s Hospital, Pittsburgh, PA 15224, USA
| | | | | | - Sue R. Beers
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Jon Detterich
- Heart Institute, Children’s Hospital Los Angeles, Los Angeles, CA 90027, USA
| | - John C. Wood
- Heart Institute, Children’s Hospital Los Angeles, Los Angeles, CA 90027, USA
| | - Cecilia W. Lo
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ashok Panigrahy
- Department of Pediatric Radiology, UPMC Children’s Hospital, Pittsburgh, PA 15224, USA
- Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
- Correspondence: ; Tel.: +1-412-692-5510; Fax: +1-412-692-6929
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6
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Oheim M, Schmidt E, Hirrlinger J. Local energy on demand: Are 'spontaneous' astrocytic Ca 2+-microdomains the regulatory unit for astrocyte-neuron metabolic cooperation? Brain Res Bull 2017; 136:54-64. [PMID: 28450076 DOI: 10.1016/j.brainresbull.2017.04.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/18/2017] [Accepted: 04/21/2017] [Indexed: 12/21/2022]
Abstract
Astrocytes are a neural cell type critically involved in maintaining brain energy homeostasis as well as signaling. Like neurons, astrocytes are a heterogeneous cell population. Cortical astrocytes show a complex morphology with a highly branched aborization and numerous fine processes ensheathing the synapses of neighboring neurons, and typically extend one process connecting to blood vessels. Recent studies employing genetically encoded fluorescent calcium (Ca2+) indicators have described 'spontaneous' localized Ca2+-transients in the astrocyte periphery that occur asynchronously, independently of signals in other parts of the cells, and that do not involve somatic Ca2+ transients; however, neither it is known whether these Ca2+-microdomains occur at or near neuronal synapses nor have their molecular basis nor downstream effector(s) been identified. In addition to Ca2+ microdomains, sodium (Na+) transients occur in astrocyte subdomains, too, most likely as a consequence of Na+ co-transport with the neurotransmitter glutamate, which also regulates mitochondrial movements locally - as do cytoplasmic Ca2+ levels. In this review, we cover various aspects of these local signaling events and discuss how structural and biophysical properties of astrocytes might foster such compartmentation. Astrocytes metabolically interact with neurons by providing energy substrates to active neurons. As a single astrocyte branch covers hundreds to thousands of synapses, it is tempting to speculate that these metabolic interactions could occur localized to specific subdomains of astrocytes, perhaps even at the level of small groups of synapses. We discuss how astrocytic metabolism might be regulated at this scale and which signals might contribute to its regulation. We speculate that the astrocytic structures that light up transiently as Ca2+-microdomains might be the functional units of astrocytes linking signaling and metabolic processes to adapt astrocytic function to local energy demands. The understanding of these local regulatory and metabolic interactions will be fundamental to fully appreciate the complexity of brain energy homeostasis as well as its failure in disease and may shed new light on the controversy about neuron-glia bi-directional signaling at the tripartite synapse.
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Affiliation(s)
- Martin Oheim
- CNRS UMR 8118, Brain Physiology Laboratory, F-75006 Paris, France; Fédération de Recherche en Neurosciences FR3636, Faculté de Sciences Fondamentales et Biomédicales, Université Paris Descartes, PRES Université Sorbonne Paris Cité (USPC), F-75006 Paris, France.
| | - Elke Schmidt
- CNRS UMR 8118, Brain Physiology Laboratory, F-75006 Paris, France; Fédération de Recherche en Neurosciences FR3636, Faculté de Sciences Fondamentales et Biomédicales, Université Paris Descartes, PRES Université Sorbonne Paris Cité (USPC), F-75006 Paris, France
| | - Johannes Hirrlinger
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University of Leipzig, D-04103 Leipzig, Germany; Dept. of Neurogenetics, Max-Planck-Institute for Experimental Medicine, D-37075 Göttingen, Germany.
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Li SJ, Luo YN, Li Y, Chen JW, Mo YH, Yuan ZX, Ou SY, Ou CY, Jiang YM, Deng XF. Sodium para-aminosalicylate protected cultured basal ganglia astrocytes from manganese-induced DNA damages and alteration of amino acid neurotransmitter levels. J Toxicol Sci 2017; 41:573-81. [PMID: 27665767 DOI: 10.2131/jts.41.573] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Sodium para-aminosalicylate (PAS-Na) was first applied successfully in clinical treatment of two manganism patients with good prognosis. However, the mechanism of how PAS-Na protects against Mn-induced neurotoxicity is still elusive. The current study was conducted to explore the effects of PAS-Na on Mn-induced basal ganglia astrocyte injury, and the involvement of amino acid neurotransmitter in vitro. Basal ganglia astrocytes were exposed to 500 μM manganese chloride (MnCl2) for 24 hr, following by 50, 150, or 450 μM PAS-Na treatment for another 24 hr. MnCl2 significantly decreased viability of astrocytes and induced DNA damages via increasing the percentage of tail DNA and Olive tail moment of DNA. Moreover, Mn interrupted amino acid neurotransmitters by decreasing Gln levels and increasing Glu, Gly levels. In contrast, PAS-Na treatment reversed the aforementioned Mn-induced toxic effects on basal ganglia astrocytes. Taken together, our results demonstrated that excessive Mn exposure may induce toxic effects on basal ganglia astrocytes, while PAS-Na could protect basal ganglia astrocytes from Mn-induced neurotoxicity.
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Affiliation(s)
- Shao-Jun Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, China
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Vignoli B, Canossa M. Glioactive ATP controls BDNF recycling in cortical astrocytes. Commun Integr Biol 2017; 10:e1277296. [PMID: 28289489 PMCID: PMC5333523 DOI: 10.1080/19420889.2016.1277296] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 12/21/2016] [Accepted: 12/21/2016] [Indexed: 11/30/2022] Open
Abstract
We have recently reported that long-term memory retention requires synaptic glia for proBDNF uptake and recycling. Through the recycling course, glial cells release endocytic BDNF, a mechanism that is activated in response to glutamate via AMPA and mGluRI/II receptors. Cortical astrocytes express receptors for many different transmitters suggesting for a complex signaling controlling endocytic BDNF secretion. Here, we demonstrated that the extracellular nucleotide ATP, activating P2X and P2Y receptors, regulates endocytic BDNF secretion in cultured astrocytes. Our data indicate that distinct glioactive molecules can participate in BDNF glial recycling and suggest that cortical astrocytes contributing to neuronal plasticity can be influenced by neurotransmitters in tune with synaptic needs.
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Affiliation(s)
- Beatrice Vignoli
- Centre for Integrative Biology (CIBIO), University of Trento , Povo (TN), Italy
| | - Marco Canossa
- Centre for Integrative Biology (CIBIO), University of Trento, Povo (TN), Italy; European Brain Research Institute (EBRI)-Rita Levi-Montalcini, Rome, Italy
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Seyedhassantehrani N, Li Y, Yao L. Dynamic behaviors of astrocytes in chemically modified fibrin and collagen hydrogels. Integr Biol (Camb) 2016; 8:624-34. [PMID: 27079938 PMCID: PMC4868780 DOI: 10.1039/c6ib00003g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Astrocytes play a critical role in supporting the normal physiological function of neurons in the central nervous system (CNS). Astrocyte transplantation can potentially promote axonal regeneration and functional recovery after spinal cord injury (SCI). Fibrin and collagen hydrogels provide growth-permissive substrates and serve as carriers for therapeutic cell transplantation into an injured spinal cord. However, the application of fibrin and collagen hydrogels may be limited due to their relatively rapid degradation rate in vivo. In this study, immature astrocytes isolated from neonatal rats were grown in fibrin hydrogels containing aprotinin and collagen hydrogels crosslinked with poly(ethylene glycol) ether tetrasuccinimidyl glutarate (4S-StarPEG), and the cell behavior in these hydrogels was studied. The cell viability of astrocytes in the hydrogels was tested using the LIVE/DEAD® assay and the AlamarBlue® assay, and this study showed that astrocytes maintained good viability in these hydrogels. The cell migration study showed that astrocytes migrated in the fibrin and collagen hydrogels, and the migration speed is similar in these hydrogels. The crosslinking of collagen hydrogels with 4S-StarPEG did not change the astrocyte migration speed. However, the addition of aprotinin in the fibrin hydrogel inhibited astrocyte migration. The expression of chondroitin sulfate proteoglycan (CSPG), including NG2, neurocan, and versican, by astrocytes grown in the hydrogels was analyzed by quantitative RT-PCR. The expression of NG2, neurocan, and versican by the cells in these hydrogels was not significantly different.
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Affiliation(s)
- Negar Seyedhassantehrani
- Department of Biological Sciences, Wichita State University, Fairmount 1845, Wichita, KS 67260, USA.
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Irizarry-Valle Y, Parker AC. An astrocyte neuromorphic circuit that influences neuronal phase synchrony. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2015; 9:175-187. [PMID: 25934997 DOI: 10.1109/tbcas.2015.2417580] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Neuromorphic circuits are designed and simulated to emulate the role of astrocytes in phase synchronization of neuronal activity. We emulate, to a first order, the ability of slow inward currents (SICs) evoked by the astrocyte, acting on extrasynaptic N-methyl-D-aspartate receptors (NMDAR) of adjacent neurons, as a mechanism for phase synchronization. We run a simulation test incorporating two small networks of neurons interacting with astrocytic microdomains. These microdomains are designed using a resistive and capacitive ladder network and their interactions occur through pass transistors. Upon enough synaptic activity, the astrocytic microdomains interact with each other, generating SIC events on synapses of adjacent neurons. Since the amplitude of SICs is several orders of magnitude larger compared to synaptic currents, a SIC event drastically enhances the excitatory postsynaptic potential (EPSP) on adjacent neurons simultaneously. This causes neurons to fire synchronously in phase. Phase synchrony holds for a duration of time proportional to the time constant of the SIC decay. Once the SIC decay has completed, the neurons are able to go back to their natural phase difference, inducing desynchronization of their firing of spikes. This paper incorporates some biological aspects observed by recent experiments showing astrocytic influence on neuronal synchronization, and intends to offer a circuit view on the hypothesis of astrocytic role on synchronous activity that could potentially lead to the binding of neuronal information.
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Ostroff LE, Manzur MK, Cain CK, Ledoux JE. Synapses lacking astrocyte appear in the amygdala during consolidation of Pavlovian threat conditioning. J Comp Neurol 2015; 522:2152-63. [PMID: 24338694 DOI: 10.1002/cne.23523] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 11/29/2013] [Accepted: 12/09/2013] [Indexed: 01/02/2023]
Abstract
There is growing evidence that astrocytes, long held to merely provide metabolic support in the adult brain, participate in both synaptic plasticity and learning and memory. Astrocytic processes are sometimes present at the synaptic cleft, suggesting that they might act directly at individual synapses. Associative learning induces synaptic plasticity and morphological changes at synapses in the lateral amygdala (LA). To determine whether astrocytic contacts are involved in these changes, we examined LA synapses after either threat conditioning (also called fear conditioning) or conditioned inhibition in adult rats by using serial section transmission electron microscopy (ssTEM) reconstructions. There was a transient increase in the density of synapses with no astrocytic contact after threat conditioning, especially on enlarged spines containing both polyribosomes and a spine apparatus. In contrast, synapses with astrocytic contacts were smaller after conditioned inhibition. This suggests that during memory consolidation astrocytic processes are absent if synapses are enlarging but present if they are shrinking. We measured the perimeter of each synapse and its degree of astrocyte coverage, and found that only about 20-30% of each synapse was ensheathed. The amount of synapse perimeter surrounded by astrocyte did not scale with synapse size, giving large synapses a disproportionately long astrocyte-free perimeter and resulting in a net increase in astrocyte-free perimeter after threat conditioning. Thus astrocytic processes do not mechanically isolate LA synapses, but may instead interact through local signaling, possibly via cell-surface receptors. Our results suggest that contact with astrocytic processes opposes synapse growth during memory consolidation.
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Affiliation(s)
- Linnaea E Ostroff
- Center for Neural Science, New York University, New York, New York, 10003
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12
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Gebicke-Haerter PJ. Engram formation in psychiatric disorders. Front Neurosci 2014; 8:118. [PMID: 24904262 PMCID: PMC4036307 DOI: 10.3389/fnins.2014.00118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 05/02/2014] [Indexed: 01/17/2023] Open
Abstract
Environmental factors substantially influence beginning and progression of mental illness, reinforcing or reducing the consequences of genetic vulnerability. Often initiated by early traumatic events, “engrams” or memories are formed that may give rise to a slow and subtle progression of psychiatric disorders. The large delay between beginning and time of onset (diagnosis) may be explained by efficient compensatory mechanisms observed in brain metabolism that use optional pathways in highly redundant molecular interactions. To this end, research has to deal with mechanisms of learning and long-term memory formation, which involves (a) epigenetic changes, (b) altered neuronal activities, and (c) changes in neuron-glia communication. On the epigenetic level, apparently DNA-methylations are more stable than histone modifications, although both closely interact. Neuronal activities basically deliver digital information, which clearly can serve as basis for memory formation (LTP). However, research in this respect has long time neglected the importance of glia. They are more actively involved in the control of neuronal activities than thought before. They can both reinforce and inhibit neuronal activities by transducing neuronal information from frequency-encoded to amplitude and frequency-modulated calcium wave patterns spreading in the glial syncytium by use of gap junctions. In this way, they serve integrative functions. In conclusion, we are dealing with two concepts of encoding information that mutually control each other and synergize: a digital (neuronal) and a wave-like (glial) computing, forming neuron-glia functional units with inbuilt feedback loops to maintain balance of excitation and inhibition. To better understand mental illness, we have to gain more insight into the dynamics of adverse environmental impact on those cellular and molecular systems. This report summarizes existing knowledge and draws some outline about further research in molecular psychiatry.
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Affiliation(s)
- Peter J Gebicke-Haerter
- Medical Faculty Mannheim, Central Institute of Mental Health, Institute of Psychopharmacology, Heidelberg University Mannheim, Germany ; Progrs. de Farmacología y Inmunología, Facultad de Medicina, Universidad de Chile Santiago, Chile
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Chu T, Zhou H, Li F, Wang T, Lu L, Feng S. Astrocyte transplantation for spinal cord injury: current status and perspective. Brain Res Bull 2014; 107:18-30. [PMID: 24878447 DOI: 10.1016/j.brainresbull.2014.05.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 05/17/2014] [Accepted: 05/19/2014] [Indexed: 02/07/2023]
Abstract
Spinal cord injury (SCI) often causes incurable neurological dysfunction because axonal regeneration in adult spinal cord is rare. Astrocytes are gradually recognized as being necessary for the regeneration after SCI as they promote axonal growth under both physiological and pathophysiological conditions. Heterogeneous populations of astrocytes have been explored for structural and functional restoration. The results range from the early variable and modest effects of immature astrocyte transplantation to the later significant, but controversial, outcomes of glial-restricted precursor (GRP)-derived astrocyte (GDA) transplantation. However, the traditional neuron-centric view and the concerns about the inhibitory roles of astrocytes after SCI, along with the sporadic studies and the lack of a comprehensive review, have led to some confusion over the usefulness of astrocytes in SCI. It is the purpose of the review to discuss the current status of astrocyte transplantation for SCI based on a dialectical view of the context-dependent manner of astrocyte behavior and the time-associated characteristics of glial scarring. Critical issues are then analyzed to reveal the potential direction of future research.
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Affiliation(s)
- Tianci Chu
- Department of Orthopaedics, Tianjin Medical University General Hospital, Anshan Road No. 154, Heping District, Tianjin 300052, PR China.
| | - Hengxing Zhou
- Department of Orthopaedics, Tianjin Medical University General Hospital, Anshan Road No. 154, Heping District, Tianjin 300052, PR China.
| | - Fuyuan Li
- Department of Orthopaedics, Tianjin Medical University General Hospital, Anshan Road No. 154, Heping District, Tianjin 300052, PR China.
| | - Tianyi Wang
- Department of Orthopaedics, Tianjin Medical University General Hospital, Anshan Road No. 154, Heping District, Tianjin 300052, PR China.
| | - Lu Lu
- Department of Orthopaedics, Tianjin Medical University General Hospital, Anshan Road No. 154, Heping District, Tianjin 300052, PR China.
| | - Shiqing Feng
- Department of Orthopaedics, Tianjin Medical University General Hospital, Anshan Road No. 154, Heping District, Tianjin 300052, PR China.
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Navarrete M, Araque A. The Cajal school and the physiological role of astrocytes: a way of thinking. Front Neuroanat 2014; 8:33. [PMID: 24904302 PMCID: PMC4032926 DOI: 10.3389/fnana.2014.00033] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 04/28/2014] [Indexed: 11/25/2022] Open
Abstract
Cajal is widely recognized by the scientific community for his important contributions to our knowledge of the neuronal organization of the nervous system. His studies on neuroglial cells are less recognized, yet they are no less relevant to our current understanding of the cellular bases of brain structure. Two pioneering studies published a century ago –“Something about the physiological significance of neuroglia” (Ramón y Cajal, 1897) and “A contribution to the understanding of neuroglia in the human brain” (Ramón y Cajal, 1913)—focused on glial cells and their role in brain physiology. Novel findings obtained using state-of-the-art and sophisticated technologies largely confirm many of the groundbreaking hypotheses proposed by Cajal related to the structural-functional properties of neuroglia. Here we propose to the reader a journey guided by the ideas of Cajal through the recent findings on the functional significance of astrocytes, the most abundant neuroglial cell type in the nervous system. Astrocyte–neuron interaction, which represents an emerging field in current neuroscience with important implications for our understanding of the cellular processes underlying brain function, has its roots in many of the original concepts proposed by Cajal.
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Affiliation(s)
- Marta Navarrete
- Functional and Systems Neurobiology, Instituto Cajal, CSIC Madrid, Spain
| | - Alfonso Araque
- Functional and Systems Neurobiology, Instituto Cajal, CSIC Madrid, Spain ; Department of Neuroscience, University of Minnesota Minneapolis, MN, USA
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Robertson JM. Astrocyte domains and the three-dimensional and seamless expression of consciousness and explicit memories. Med Hypotheses 2013; 81:1017-24. [DOI: 10.1016/j.mehy.2013.09.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 08/30/2013] [Accepted: 09/13/2013] [Indexed: 01/19/2023]
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Macdonald CL, Silva GA. A positive feedback cell signaling nucleation model of astrocyte dynamics. FRONTIERS IN NEUROENGINEERING 2013; 6:4. [PMID: 23847529 PMCID: PMC3706728 DOI: 10.3389/fneng.2013.00004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/10/2013] [Indexed: 11/13/2022]
Abstract
We constructed a model of calcium signaling in astrocyte neural glial cells that incorporates a positive feedback nucleation mechanism, whereby small microdomain increases in local calcium can stochastically produce global cellular and intercellular network scale dynamics. The model is able to simultaneously capture dynamic spatial and temporal heterogeneities associated with intracellular calcium transients in individual cells and intercellular calcium waves (ICW) in spatially realistic networks of astrocytes, i.e., networks where the positions of cells were taken from real in vitro experimental data of spontaneously forming sparse networks, as opposed to artificially constructed grid networks or other non-realistic geometries. This is the first work we are aware of where an intracellular model of calcium signaling that reproduces intracellular dynamics inherently accounts for intercellular network dynamics. These results suggest that a nucleation type mechanism should be further investigated experimentally in order to test its contribution to calcium signaling in astrocytes and in other cells more broadly. It may also be of interest in engineered neuromimetic network systems that attempt to emulate biological signaling and information processing properties in synthetic hardwired neuromorphometric circuits or coded algorithms.
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Karimi-Abdolrezaee S, Billakanti R. Reactive astrogliosis after spinal cord injury-beneficial and detrimental effects. Mol Neurobiol 2012; 46:251-64. [PMID: 22684804 DOI: 10.1007/s12035-012-8287-4] [Citation(s) in RCA: 266] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 05/29/2012] [Indexed: 11/29/2022]
Abstract
Reactive astrogliosis is a pathologic hallmark of spinal cord injury (SCI). It is characterised by profound morphological, molecular, and functional changes in astrocytes that occur within hours of SCI and evolves as time elapses after injury. Astrogliosis is a defense mechanism to minimize and repair the initial damage but eventually leads to some detrimental effects. Reactive astrocytes secrete a plethora of both growth promoting and inhibitory factors after SCI. However, the production of inhibitory components surpasses the growth stimulating factors, thus, causing inhibitory effects. In severe cases of injury, astrogliosis results in the formation of irreversible glial scarring that acts as regeneration barrier due to the expression of inhibitory components such as chondroitin sulfate proteoglycans. Scar formation was therefore recognized from a negative perspective for many years. Accumulating evidence from pharmacological and genetic studies now signifies the importance of astrogliosis and its timing for spinal cord repair. These studies have advanced our knowledge regarding signaling pathways and molecular mediators, which trigger and modulate reactive astrocytes and scar formation. In this review, we discuss the recent advances in this field. We also review therapeutic strategies that have been developed to target astrocytes reactivity and glial scaring in the environment of SCI. Astrocytes play pivotal roles in governing SCI mechanisms, and it is therefore crucial to understand how their activities can be targeted efficiently to harness their potential for repair and regeneration after SCI.
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Affiliation(s)
- Soheila Karimi-Abdolrezaee
- Regenerative Medicine Program, Departments of Physiology and Biochemistry and Medical Genetics, the Spinal Cord Research Center, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
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Mostafeezur RM, Zakir HM, Yamada Y, Yamamura K, Iwata K, Sessle BJ, Kitagawa J. The effect of minocycline on the masticatory movements following the inferior alveolar nerve transection in freely moving rats. Mol Pain 2012; 8:27. [PMID: 22515433 PMCID: PMC3416740 DOI: 10.1186/1744-8069-8-27] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 04/20/2012] [Indexed: 01/25/2023] Open
Abstract
Background To determine the effects of inferior alveolar nerve transection (IAN-X) on masticatory movements in freely moving rats and to test if microglial cells in the trigeminal principal sensory nucleus (prV) or motor nucleus (motV) may be involved in modulation of mastication, the effects of microglial cell inhibitor minocycline (MC) on masticatory jaw movements, microglia (Iba1) immunohistochemistry and the masticatory jaw movements and related masticatory muscle EMG activities were studied in IAN-X rats. Results The number of Iba1-immunoreactive (IR) cells both in prV and motV was significantly larger in IAN-X rats compared with sham rats on day 3 after IAN-X. The intraperitoneal (i.p.) administration of MC caused a significant reduction of the number of Iba1-IR cells both in prV and motV that was evident on day 14 after IAN-X. Furthermore, a significant reduction of the number of Iba1-IR cells could be observed in motV but not in prV after microinjection (m.i.) of MC into the motV of IAN-X rats. The rats also exhibited a significant decrease in the head-withdrawal threshold on the side ipsilateral to the IAN-X compared to the threshold before IAN-X and it lasted to day 14. In addition, IAN-X markedly affected the ability to rat to carry out mastication. The number of complete masticatory sequences was significantly decreased. Furthermore, the total masticatory sequence time and food preparatory (PP) period duration was significantly elongated in compared to sham rats. Although IAN-X significantly affected the total number of chewing cycles within the RC period of a masticatory sequence, it had no effect on the duration of the chewing cycles. On the other hand, systemic administration of MC (both i.p. and m.i.) in IAN-X rats significantly improved decreased head-withdrawal threshold and the impaired masticatory jaw movements. Conclusions The present findings reveal that the strong modulation of masticatory jaw movements occurs following microglial cell activation after IAN-X, and the modulation recovers after inhibition of the microglial cell activation by MC, suggesting that microglial cell activation in the motV as well as in the prV has a pivotal role in modulating mastication following trigeminal nerve injury associated with orofacial neuropathic pain.
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Affiliation(s)
- Rahman Md Mostafeezur
- Division of Oral Physiology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, 2-5274, Gakkocho-dori, Niigata, 951-8514, Japan
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19
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Kim HSR, Seto-Ohshima A, Nishiyama H, Itohara S. Normal delay eyeblink conditioning in mice devoid of astrocytic S100B. Neurosci Lett 2010; 489:148-53. [PMID: 21146588 DOI: 10.1016/j.neulet.2010.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 11/30/2010] [Accepted: 12/01/2010] [Indexed: 10/18/2022]
Abstract
S100B is a small calcium binding protein synthesized and secreted mostly by astrocytes. Mice devoid of S100B (S100B-KO) develop without detectable anatomic abnormalities of the brain, but exhibit enhanced hippocampal long-term potentiation and enhanced performance in hippocampus-dependent learning and memory tasks, indicating that S100B has a crucial role in hippocampal neuronal plasticity. In the present study, we examined whether S100B has a similar role in the cerebellar regions, because Bergmann glia, a specialized subset of astrocytes in the cerebellar cortex, express a particularly large amount of S100B under physiologic conditions. Unlike in the hippocampus-dependent tasks, S100B-KO mice were indistinguishable from wild-type mice in both cerebellum-dependent motor coordination and delay eyeblink conditioning, a well-established paradigm for cerebellum-dependent learning and memory. These results suggest that S100B has differential roles in the hippocampus and cerebellum.
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Affiliation(s)
- Hye-Soo R Kim
- Laboratory for Behavioral Genetics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako 351-0198, Japan
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20
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Wade JJ, McDaid LJ, Santos JA, Sayers HM. SWAT: A Spiking Neural Network Training Algorithm for Classification Problems. ACTA ACUST UNITED AC 2010; 21:1817-30. [PMID: 20876015 DOI: 10.1109/tnn.2010.2074212] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- John J Wade
- Intelligent Systems Research Center, University of Ulster, School of Computing and Intelligent Systems, Derry, Northern Ireland, U.K.
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21
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Glia: the many ways to modulate synaptic plasticity. Neurochem Int 2010; 57:440-5. [PMID: 20193723 DOI: 10.1016/j.neuint.2010.02.013] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 02/15/2010] [Accepted: 02/19/2010] [Indexed: 11/21/2022]
Abstract
Synaptic plasticity consists in a change in synaptic strength that is believed to be the basis of learning and memory. Synaptic plasticity has been for a very long period of time a hallmark of neurons. Recent advances in physiology of glial cells indicate that astrocyte and microglia possess all the features to participate and modulate the various form of synaptic plasticity. Indeed beside their respective supportive and immune functions an increasing number of study demonstrate that astrocytes and microglia express receptors for most neurotransmitters and release neuroactive substances that have been shown to modulate neuronal activity and synaptic plasticity. Because glial cells are all around synapses and release a wide variety of neuroactive molecule during physiological and pathological conditions, glial cells have been reported to modulate synaptic plasticity in many different ways. From change in synaptic coverage, to release of chemokines and cytokines up to dedicated "glio" transmitters release, glia were reported to affect synaptic scaling, homeostatic plasticity, metaplasticity, long-term potentiation and long-term depression.
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Astroglia in medullary dorsal horn (trigeminal spinal subnucleus caudalis) are involved in trigeminal neuropathic pain mechanisms. J Neurosci 2009; 29:11161-71. [PMID: 19741123 DOI: 10.1523/jneurosci.3365-09.2009] [Citation(s) in RCA: 165] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The aim of this study was to investigate whether astroglia in the medullary dorsal horn (trigeminal spinal subnucleus caudalis; Vc) may be involved in orofacial neuropathic pain following trigeminal nerve injury. The effects of intrathecal administration of the astroglial aconitase inhibitor sodium fluoroacetate (FA) were tested on Vc astroglial hyperactivity [as revealed by glial fibrillary acid protein (GFAP) labeling], nocifensive behavior, Vc extracellular signal-regulated kinase phosphorylation (pERK), and Vc neuronal activity in inferior alveolar nerve-transected (IANX) rats. Compared with sham-control rats, a significant increase occurred in GFAP-positive cells in ipsilateral Vc at postoperative day 7 in IANX rats, which was prevented following FA administration. FA significantly increased the reduced head withdrawal latency to high-intensity heat stimulation of the maxillary whisker pad skin in IANX rats, although it did not significantly affect the reduced escape threshold to low-intensity mechanical stimulation of the whisker skin in IANX rats. FA also significantly reduced the increased number of pERK-like immunoreactive cells in Vc and the enhanced Vc nociceptive neuronal responses following high-intensity skin stimulation that were documented in IANX rats, and glutamine administration restored the enhanced responses. These various findings provide the first documentation that astroglia is involved in the enhanced nociceptive responses of functionally identified Vc nociceptive neurons and in the associated orofacial hyperalgesia following trigeminal nerve injury.
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23
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Perea G, Navarrete M, Araque A. Tripartite synapses: astrocytes process and control synaptic information. Trends Neurosci 2009; 32:421-31. [DOI: 10.1016/j.tins.2009.05.001] [Citation(s) in RCA: 1201] [Impact Index Per Article: 75.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Revised: 05/07/2009] [Accepted: 05/08/2009] [Indexed: 11/26/2022]
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Härtel K, Schnell C, Hülsmann S. Astrocytic calcium signals induced by neuromodulators via functional metabotropic receptors in the ventral respiratory group of neonatal mice. Glia 2009; 57:815-27. [DOI: 10.1002/glia.20808] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Viola GG, Rodrigues L, Américo JC, Hansel G, Vargas RS, Biasibetti R, Swarowsky A, Gonçalves CA, Xavier LL, Achaval M, Souza DO, Amaral OB. Morphological changes in hippocampal astrocytes induced by environmental enrichment in mice. Brain Res 2009; 1274:47-54. [PMID: 19374889 DOI: 10.1016/j.brainres.2009.04.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 03/30/2009] [Accepted: 04/07/2009] [Indexed: 12/20/2022]
Abstract
Environmental enrichment is known to induce plastic changes in the brain, including morphological changes in hippocampal neurons, with increases in synaptic and spine densities. In recent years, the evidence for a role of astrocytes in regulating synaptic transmission and plasticity has increased, and it is likely that morphological and functional changes in astrocytes play an important role in brain plasticity. Our study was designed to evaluate changes in astrocytes induced by environmental enrichment in the CA1 region of the hippocampus, focusing on astrocytic density and on morphological changes in astrocytic processes. After 8 weeks of environmental enrichment starting at weaning, male CF-1 mice presented no significant changes in astrocyte number or in the density of glial fibrillary acidic protein (GFAP) immunoreactivity in the stratum radiatum. However, they did present changes in astrocytic morphology in the same region, as expressed by a significant increase in the ramification of astrocytic processes measured by the Sholl concentric circles method, as well as by an increase in the number and length of primary processes extending in a parallel orientation to CA1 nerve fibers. This led astrocytes to acquire a more stellate morphology, a fact which could be related to the increase in hippocampal synaptic density observed in previous studies. These findings corroborate the idea that structural changes in astrocytic networks are an integral part of plasticity processes occurring in the brain.
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Affiliation(s)
- Giordano G Viola
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil
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Abstract
Astrocytes were classically considered as simple supportive cells for neurons without a significant role in information processing by the nervous system. However, considerable amounts of evidence obtained by several groups during the past years demonstrated the existence of a bidirectional communication between astrocytes and neurons, which prompted a re-examination of the role of astrocytes in the physiology of the nervous system. While neurons base their excitability on electrical signals generated across the membrane, astrocytes base their cellular excitability on variations of the Ca2+ concentration in the cytosol. This article discusses our current knowledge of the properties of the synaptically evoked astrocyte Ca2+ signal, which reveals that astrocytes display integrative properties for synaptic information processing. Astrocytes respond selectively to different axon pathways, discriminate between the activity of different synapses and their Ca2+ signal is non-linearly modulated by the simultaneous activity of different synaptic inputs. Furthermore, this Ca2+ signal modulation depends on astrocyte cellular intrinsic properties and is bidirectionally regulated by the level of synaptic activity. Finally, astrocyte Ca2+ elevations can trigger the release of gliotransmitters, which modulate neuronal activity as well as synaptic transmission and plasticity, hence granting the bidirectional communication with neurons. Consequently, astrocytes can be considered as cellular elements involved in information processing by the nervous system.
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27
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Memory processing in the avian hippocampus involves interactions between beta-adrenoceptors, glutamate receptors, and metabolism. Neuropsychopharmacology 2008; 33:2831-46. [PMID: 18256591 DOI: 10.1038/npp.2008.5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Noradrenaline is known to modulate memory formation in the mammalian hippocampus. We have examined how noradrenaline and selective beta-adrenoceptor (AR) agonists affect memory consolidation and how antagonists inhibit memory consolidation in the avian hippocampus. Injection of selective beta-AR agonists and antagonists at specific times within 30 min of a weakly or strongly reinforced, single-trial, bead discrimination learning test in 1-day-old chicks allowed us to determine the pattern of beta-AR involvement in hippocampal memory processing. Different beta-AR subtypes were recruited in temporal sequence after learning in the order beta(1), beta(3), and beta(2.) We provide evidence that the effect of manipulation of beta(1)-ARs by selective agonists and antagonists within 2.5 min of training parallels the action of NMDA receptor agonists and antagonists. Activation of beta(3)- and beta(2)-ARs facilitated memory but utilized different mechanisms: beta(3)-ARs by stimulating glucose uptake and metabolism, and beta(2)-ARs by increasing the breakdown of glycogen--with both metabolic events occurring in astrocytes and affecting intermediate memory. The different receptors are activated at different times within the lifetime of labile memory and within 30 min of learning. We have defined separate roles for the three beta-ARs in memory and demonstrated that the avian hippocampus is involved in learning and memory in much the same way as the hippocampus in the mammalian brain.
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28
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Wei F, Guo W, Zou S, Ren K, Dubner R. Supraspinal glial-neuronal interactions contribute to descending pain facilitation. J Neurosci 2008; 28:10482-95. [PMID: 18923025 PMCID: PMC2660868 DOI: 10.1523/jneurosci.3593-08.2008] [Citation(s) in RCA: 244] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 09/02/2008] [Indexed: 01/13/2023] Open
Abstract
Spinal glial reaction and proinflammatory cytokine induction play an important role in the development of chronic pain states after tissue and nerve injury. The present study investigated the cellular and molecular mechanisms underlying descending facilitation of neuropathic pain with an emphasis on supraspinal glial-neuronal relationships. An early and transient reaction of microglia and prolonged reaction of astrocytes were found after chronic constriction injury (CCI) of the rat infraorbital nerve in the rostral ventromedial medulla (RVM), a major component of brainstem descending pain modulatory circuitry. There were prolonged elevations of cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) after CCI, and they were expressed in RVM astrocytes at 14 d after injury. Intra-RVM injection of microglial and astrocytic inhibitors attenuated mechanical hyperalgesia and allodynia at 3 and 14 d after CCI, respectively. Moreover, TNFR1 and IL-1R, receptors for TNF-alpha and IL-1beta, respectively, were expressed primarily in RVM neurons exhibiting immunoreactivity to the NMDA receptor (NMDAR) subunit NR1. CCI increased TNFR1 and IL-1R levels and NR1 phosphorylation in the RVM. Neutralization of endogenous TNF-alpha and IL-1beta in the RVM significantly reduced CCI-induced behavioral hypersensitivity and attenuated NR1 phosphorylation. Finally, intra-RVM administration of recombinant TNF-alpha or IL-1beta upregulated NR1 phosphorylation and caused a reversible and NMDAR-dependent allodynia in normal rats, further suggesting that TNF-alpha and IL-1beta couple glial hyperactivation with NMDAR function. These studies have addressed a novel contribution of supraspinal astrocytes and associated cytokines as well as central glial-neuronal interactions to the enhancement of descending facilitation of neuropathic pain.
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Affiliation(s)
- Feng Wei
- Department of Neural and Pain Sciences, Dental School, Program in Neuroscience, University of Maryland, Baltimore, Maryland 21201, USA.
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29
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Kumaria A, Tolias CM, Burnstock G. ATP signalling in epilepsy. Purinergic Signal 2008; 4:339-46. [PMID: 18568425 PMCID: PMC2583203 DOI: 10.1007/s11302-008-9115-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Accepted: 05/12/2008] [Indexed: 01/23/2023] Open
Abstract
This paper focuses on a role for ATP neurotransmission and gliotransmission in the pathophysiology of epileptic seizures. ATP along with gap junctions propagates the glial calcium wave, which is an extraneuronal signalling pathway in the central nervous system. Recently astrocyte intercellular calcium waves have been shown to underlie seizures, and conventional antiepileptic drugs have been shown to attenuate these calcium waves. Blocking ATP-mediated gliotransmission, therefore, represents a potential target for antiepileptic drugs. Furthermore, while knowledge of an antiepileptic role for adenosine is not new, a recent study showed that adenosine accumulates from the hydrolysis of accumulated ATP released by astrocytes and is believed to inhibit distant synapses by acting on adenosine receptors. Such a mechanism is consistent with a surround-inhibitory mechanism whose failure would predispose to seizures. Other potential roles for ATP signalling in the initiation and spread of epileptiform discharges may involve synaptic plasticity and coordination of synaptic networks. We conclude by making speculations about future developments.
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Affiliation(s)
- Ashwin Kumaria
- Department of Neurosurgery, King's College Hospital, London, UK,
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Yin Z, Aschner JL, Santos APD, Aschner M. Mitochondrial-dependent manganese neurotoxicity in rat primary astrocyte cultures. Brain Res 2008; 1203:1-11. [PMID: 18313649 PMCID: PMC2327216 DOI: 10.1016/j.brainres.2008.01.079] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 12/13/2007] [Accepted: 01/22/2008] [Indexed: 12/15/2022]
Abstract
Chronic exposure to excessive levels of Mn results in a movement disorder termed manganism, which resembles Parkinson's disease (PD). The pathogenic mechanisms underlying this disorder are not fully understood. Several lines of evidence implicate astrocytes as an early target of Mn neurotoxicity. In the present study, we investigated the effects of Mn on mitochondrial function. Primary astrocyte cultures were prepared from cerebral cortices of one-day-old Sprague-Dawley rats. We have examined the cellular toxicity of Mn and its effects on the phosphorylation of extracellular signal-regulated kinase (ERK) and activation of the precursor protein of caspase-3. The potentiometric dye, tetramethyl rhodamine ethyl ester (TMRE), was used to assess the effect of Mn on astrocytic mitochondrial inner membrane potential (DeltaPsi(m)). Our studies show that, in a concentration-dependent manner, Mn induces significant (p<0.05) activation of astrocyte caspase-3 and phosphorylated extracellular signal-regulated kinase (p-ERK). Mn treatment (1 and 6 h) also significantly (p<0.01) dissipates the DeltaPsi(m) in astrocytes as evidenced by a decrease in mitochondrial TMRE fluorescence. These results suggest that activations of astrocytic caspase-3 and ERK are involved in Mn-induced neurotoxicity via mitochondrial-dependent pathways.
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Affiliation(s)
- Zhaoobao Yin
- Department of Pediatrics, Vanderbilt University Medical Center, TN, USA
- Kennedy Center for Research on Human Development , TN, USA
| | - Judy L. Aschner
- Department of Pediatrics, Vanderbilt University Medical Center, TN, USA
- Kennedy Center for Research on Human Development , TN, USA
| | | | - Michael Aschner
- Department of Pediatrics, Vanderbilt University Medical Center, TN, USA
- Department of Pharmacology, Vanderbilt University Medical Center, TN, USA
- Kennedy Center for Research on Human Development , TN, USA
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Howell GR, Libby RT, Jakobs TC, Smith RS, Phalan FC, Barter JW, Barbay JM, Marchant JK, Mahesh N, Porciatti V, Whitmore AV, Masland RH, John SWM. Axons of retinal ganglion cells are insulted in the optic nerve early in DBA/2J glaucoma. J Cell Biol 2007; 179:1523-37. [PMID: 18158332 PMCID: PMC2373494 DOI: 10.1083/jcb.200706181] [Citation(s) in RCA: 484] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Accepted: 11/19/2007] [Indexed: 01/21/2023] Open
Abstract
Here, we use a mouse model (DBA/2J) to readdress the location of insult(s) to retinal ganglion cells (RGCs) in glaucoma. We localize an early sign of axon damage to an astrocyte-rich region of the optic nerve just posterior to the retina, analogous to the lamina cribrosa. In this region, a network of astrocytes associates intimately with RGC axons. Using BAX-deficient DBA/2J mice, which retain all of their RGCs, we provide experimental evidence for an insult within or very close to the lamina in the optic nerve. We show that proximal axon segments attached to their cell bodies survive to the proximity of the lamina. In contrast, axon segments in the lamina and behind the eye degenerate. Finally, the Wld(s) allele, which is known to protect against insults to axons, strongly protects against DBA/2J glaucoma and preserves RGC activity as measured by pattern electroretinography. These experiments provide strong evidence for a local insult to axons in the optic nerve.
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García-Marín V, García-López P, Freire M. Cajal's contributions to glia research. Trends Neurosci 2007; 30:479-87. [PMID: 17765327 DOI: 10.1016/j.tins.2007.06.008] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 06/08/2007] [Accepted: 06/14/2007] [Indexed: 11/26/2022]
Abstract
In 1906, Santiago Ramón y Cajal was awarded the Nobel Prize in Physiology or Medicine in recognition of his work on the structure of neurons and their connections. What is less well known is that he also had a keen interest in glia and developed specific staining methods for their study. In addition to describing their morphology, he speculated on a role for glia in sleep and wakefulness and even in executive brain functions such as attention. In this article, we focus on Cajal's histological research into glial cells; this research includes original drawings of astrocytes, oligodendrocytes, microglia and radial glia, as well as his scientific writings. We aim to show that, concerning glia as well as neurons, Cajal was far ahead of his time.
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Affiliation(s)
- Virginia García-Marín
- Museum Ramón y Cajal, Instituto Cajal, CSIC Avda. Doctor Arce 37, Madrid 28002, Spain.
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Kimelberg HK. Supportive or information-processing functions of the mature protoplasmic astrocyte in the mammalian CNS? A critical appraisal. NEURON GLIA BIOLOGY 2007; 3:181-9. [PMID: 18545675 PMCID: PMC2423726 DOI: 10.1017/s1740925x08000094] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
It has been proposed that astrocytes should no longer be viewed purely as support cells for neurons, such as providing a constant environment and metabolic substrates, but that they should also be viewed as being involved in affecting synaptic activity in an active way and, therefore, an integral part of the information-processing properties of the brain. This essay discusses the possible differences between a support and an instructive role, and concludes that any distinction has to be blurred. In view of this, and a brief overview of the nature of the data, the new evidence seems insufficient to conclude that the physiological roles of mature astrocytes go beyond a general support role. I propose a model of mature protoplasmic astrocyte function that is drawn from the most recent data on their structure, the domain concept and their syncytial characteristics, of an independent rather than integrative functioning of the ends of each process where the activities that affect synaptic activity and blood vessel diameter will be concentrated.
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Affiliation(s)
- Harold K Kimelberg
- Neural and Vascular Biology, Ordway Research Institute, Inc., 150 New Scotland Ave, Albany, NY 12208, USA.
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Rodríguez-Santiago M, Mendoza-Torres M, Jiménez-Bremont JF, López-Revilla R. Knockout of the trcp3 gene causes a recessive neuromotor disease in mice. Biochem Biophys Res Commun 2007; 360:874-9. [PMID: 17624307 DOI: 10.1016/j.bbrc.2007.06.150] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Indexed: 10/23/2022]
Abstract
Delta202 mice carry a transgene encoding the SV40 T antigen. Mice homozygous for the transgene develop paralysis and atrophy starting at week 4 and die around week 12. To determine the molecular basis of the neurological syndrome, we identified the transgene insertion site by sequencing two successive nested PCR products amplified with reverse primers from circularized Delta202 mouse DNA fragments generated through XbaI digestion. From the cloned products a consensus 542 bp sequence was obtained, with 409 bp corresponding to the transgene ends surrounding a 133 bp sequence formed by a left 128 bp segment and a right 8 bp segment. The 128 bp sequence matched the chr3:36811347-364811421 sequence corresponding to the promoter region of the trpc3 gene between nucleotides -54 and -53 from the transcriptional start point (+1). Complementary DNA amplification from total brain RNA demonstrated a lack of TRPC3 transcripts in Delta202 mouse brain. The neurologic syndrome of Delta202 mice thus appears to be a monogenic recessive neuromotor disease caused by interruption of the trpc3 gene promoter due to the transgene insertion which in turn blocks the transcription and knocks out TRPC3 calcium channels leading to a failure in the postnatal development of the central nervous system.
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De Sampaio Schitine C, Cussa Kubrusly RC, De Melo Reis RA, Yamasaki EN, De Mello MCF, De Mello FG. GABA uptake by purified avian Müller glia cells in culture. Neurotox Res 2007; 12:145-53. [DOI: 10.1007/bf03033923] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Oheim M, Kirchhoff F, Stühmer W. Calcium microdomains in regulated exocytosis. Cell Calcium 2006; 40:423-39. [PMID: 17067670 DOI: 10.1016/j.ceca.2006.08.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Accepted: 08/23/2006] [Indexed: 11/19/2022]
Abstract
Katz and co-workers showed that Ca(2+) triggers exocytosis. The existence of sub-micrometer domains of greater than 100 microM [Ca(2+)](i) was postulated on theoretical grounds. Using a modified, low-affinity aequorin, Llinas et al. were the first to demonstrate the existence of Ca(2+) 'microdomains' in squid presynaptic terminals. Over the past several years, it has become clear that individual Ca(2+) nano- and microdomains forming around the mouth of voltage-gated Ca(2+) channels ascertain the tight coupling of fast synaptic vesicle release to membrane depolarization by action potentials. Recent work has established different geometric arrangements of vesicles and Ca(2+) channels at different central synapses and pointed out the role of Ca(2+) syntillas - localized, store operated Ca(2+) signals - in facilitation and spontaneous release. The coupling between Ca(2+) increase and evoked exocytosis is more sluggish in peripheral terminals and neuroendocrine cells, where channels are less clustered and Ca(2+) comes from different sources, including Ca(2+) influx via the plasma membrane and the mobilization of Ca(2+) from intracellular stores. Finally, also non- (electrically) excitable cells display highly localized Ca(2+) signaling domains. We discuss in particular the organization of structural microdomains of Bergmann glia, specialized astrocytes of the cerebellum that have only recently been considered as secretory cells. Glial microdomains are the spatial substrate for functionally segregated Ca(2+) signals upon metabotropic activation. Our review emphasizes the large diversity of different geometric arrangements of vesicles and Ca(2+) sources, leading to a wide spectrum of Ca(2+) signals triggering release.
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Affiliation(s)
- Martin Oheim
- Molecular and Cellular Biophysics of Synaptic Transmission, INSERM, U603, Paris, France.
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Kielar C, Maddox L, Bible E, Pontikis CC, Macauley SL, Griffey MA, Wong M, Sands MS, Cooper JD. Successive neuron loss in the thalamus and cortex in a mouse model of infantile neuronal ceroid lipofuscinosis. Neurobiol Dis 2006; 25:150-62. [PMID: 17046272 PMCID: PMC1866219 DOI: 10.1016/j.nbd.2006.09.001] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 08/29/2006] [Accepted: 09/03/2006] [Indexed: 11/16/2022] Open
Abstract
Infantile neuronal ceroid lipofuscinosis (INCL) is caused by deficiency of the lysosomal enzyme, palmitoyl protein thioesterase 1 (PPT1). We have investigated the onset and progression of pathological changes in Ppt1 deficient mice (Ppt1-/-) and the development of their seizure phenotype. Surprisingly, cortical atrophy and neuron loss occurred only late in disease progression but were preceded by localized astrocytosis within individual thalamic nuclei and the progressive loss of thalamic neurons that relay different sensory modalities to the cortex. This thalamic neuron loss occurred first within the visual system and only subsequently in auditory and somatosensory relay nuclei or the inhibitory reticular thalamic nucleus. The loss of granule neurons and GABAergic interneurons followed in each corresponding cortical region, before the onset of seizure activity. These findings provide novel evidence for successive neuron loss within the thalamus and cortex in Ppt1-/- mice, revealing the thalamus as an important early focus of INCL pathogenesis.
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Affiliation(s)
- Catherine Kielar
- Pediatric Storage Disorders Laboratory, Box P040, MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, De Crespigny Park, King's College London, London, SE5 8AF, UK
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Cooper JD, Russell C, Mitchison HM. Progress towards understanding disease mechanisms in small vertebrate models of neuronal ceroid lipofuscinosis. BIOCHIMICA ET BIOPHYSICA ACTA 2006; 1762:873-89. [PMID: 17023146 DOI: 10.1016/j.bbadis.2006.08.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Revised: 07/28/2006] [Accepted: 08/02/2006] [Indexed: 02/03/2023]
Abstract
Model systems provide an invaluable tool for investigating the molecular mechanisms underlying the NCLs, devastating neurodegenerative disorders that affect the relatively inaccessible tissues of the central nervous system. These models have enabled the assessment of behavioural, pathological, cellular, and molecular abnormalities, and also allow for development and evaluation of novel therapies. This review highlights the relative advantages of the two available small vertebrate species, the mouse and zebrafish, in modelling NCL disease, summarising how these have been useful in NCL research and their potential for the development and testing of prospective disease treatments. A panel of mouse mutants is available representing all the cloned NCL gene disorders (Cathepsin D, CLN1, CLN2, CLN3, CLN5, CLN6, CLN8). These NCL mice all have progressive neurodegenerative phenotypes that closely resemble the pathology of human NCL. The analysis of these models has highlighted several novel aspects underlying NCL pathogenesis including the selective nature of neurodegeneration, evidence for glial responses that precede neuronal loss and identification of the thalamus as an important pathological target early in disease progression. Studies in mice have also highlighted an unexpected heterogeneity underlying NCL phenotypes, and novel potential NCL-like mouse models have been described including mice with mutations in cathepsins, CLC chloride channels, and other lysosome-related genes. These new models are likely to provide significant new information on the spectrum of NCL disease. Information on NCL mice is available in the NCL Mouse Model Database (). There are homologs of most of the NCL genes in zebrafish, and NCL zebrafish models are currently in development. This model system provides additional advantages to those provided by NCL mouse models including high-throughput mutational, pharmacogenetic and therapeutic technique analyses. Mouse and zebrafish models are an important shared resource for NCL research, offering a unique possibility to dissect disease mechanisms and to develop therapeutic approaches.
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Affiliation(s)
- Jonathan D Cooper
- Pediatric Storage Disorders Laboratory, Department of Neuroscience, and Centre for the Cellular Basis of Behaviour, MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, De Crespigny Park, King's College London, London, UK
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