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Marasco A, Spera E, De Falco V, Iuorio A, Lupascu CA, Solinas S, Migliore M. An Adaptive Generalized Leaky Integrate-and-Fire Model for Hippocampal CA1 Pyramidal Neurons and Interneurons. Bull Math Biol 2023; 85:109. [PMID: 37792146 PMCID: PMC10550887 DOI: 10.1007/s11538-023-01206-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 08/24/2023] [Indexed: 10/05/2023]
Abstract
Full-scale morphologically and biophysically realistic model networks, aiming at modeling multiple brain areas, provide an invaluable tool to make significant scientific advances from in-silico experiments on cognitive functions to digital twin implementations. Due to the current technical limitations of supercomputer systems in terms of computational power and memory requirements, these networks must be implemented using (at least) simplified neurons. A class of models which achieve a reasonable compromise between accuracy and computational efficiency is given by generalized leaky integrate-and fire models complemented by suitable initial and update conditions. However, we found that these models cannot reproduce the complex and highly variable firing dynamics exhibited by neurons in several brain regions, such as the hippocampus. In this work, we propose an adaptive generalized leaky integrate-and-fire model for hippocampal CA1 neurons and interneurons, in which the nonlinear nature of the firing dynamics is successfully reproduced by linear ordinary differential equations equipped with nonlinear and more realistic initial and update conditions after each spike event, which strictly depends on the external stimulation current. A mathematical analysis of the equilibria stability as well as the monotonicity properties of the analytical solution for the membrane potential allowed (i) to determine general constraints on model parameters, reducing the computational cost of an optimization procedure based on spike times in response to a set of constant currents injections; (ii) to identify additional constraints to quantitatively reproduce and predict the experimental traces from 85 neurons and interneurons in response to any stimulation protocol using constant and piecewise constant current injections. Finally, this approach allows to easily implement a procedure to create infinite copies of neurons with mathematically controlled firing properties, statistically indistinguishable from experiments, to better reproduce the full range and variability of the firing scenarios observed in a real network.
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Affiliation(s)
- Addolorata Marasco
- Department of Mathematics and Applications, University of Naples Federico II, Via Cintia ed. 5A, 80126 Naples, Italy
- Institute of Biophysics, National Research Council, Via Ugo La Malfa 153, 90146 Palermo, Italy
| | - Emiliano Spera
- Institute of Biophysics, National Research Council, Via Ugo La Malfa 153, 90146 Palermo, Italy
| | - Vittorio De Falco
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138 Naples, Napoli Italy
- Istituto Nazionale di Fisica Nucleare di Napoli, Via Cintia ed. 6, 80126 Naples, Napoli Italy
| | - Annalisa Iuorio
- Faculty of Mathematics, University of Vienna, Oskar-Morgenstern-Platz 1, 1090 Vienna, Austria
- Department of Engineering, Parthenope University of Naples, Centro Direzionale - Isola C4, 80143 Naples, Italy
| | - Carmen Alina Lupascu
- Institute of Biophysics, National Research Council, Via Ugo La Malfa 153, 90146 Palermo, Italy
| | - Sergio Solinas
- Department of Biomedical Science, University of Sassari, Viale San Pietro 23, 07100 Sassari, Italy
| | - Michele Migliore
- Institute of Biophysics, National Research Council, Via Ugo La Malfa 153, 90146 Palermo, Italy
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Büchel J, Zendrikov D, Solinas S, Indiveri G, Muir DR. Supervised training of spiking neural networks for robust deployment on mixed-signal neuromorphic processors. Sci Rep 2021; 11:23376. [PMID: 34862429 PMCID: PMC8642544 DOI: 10.1038/s41598-021-02779-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/22/2021] [Indexed: 11/14/2022] Open
Abstract
Mixed-signal analog/digital circuits emulate spiking neurons and synapses with extremely high energy efficiency, an approach known as "neuromorphic engineering". However, analog circuits are sensitive to process-induced variation among transistors in a chip ("device mismatch"). For neuromorphic implementation of Spiking Neural Networks (SNNs), mismatch causes parameter variation between identically-configured neurons and synapses. Each chip exhibits a different distribution of neural parameters, causing deployed networks to respond differently between chips. Current solutions to mitigate mismatch based on per-chip calibration or on-chip learning entail increased design complexity, area and cost, making deployment of neuromorphic devices expensive and difficult. Here we present a supervised learning approach that produces SNNs with high robustness to mismatch and other common sources of noise. Our method trains SNNs to perform temporal classification tasks by mimicking a pre-trained dynamical system, using a local learning rule from non-linear control theory. We demonstrate our method on two tasks requiring temporal memory, and measure the robustness of our approach to several forms of noise and mismatch. We show that our approach is more robust than common alternatives for training SNNs. Our method provides robust deployment of pre-trained networks on mixed-signal neuromorphic hardware, without requiring per-device training or calibration.
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Affiliation(s)
- Julian Büchel
- SynSense, Thurgauerstrasse 40, 8050, Zurich, Switzerland
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Dmitrii Zendrikov
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Sergio Solinas
- Department of Biomedical Science, University of Sassari, Piazza Università, 21, 07100, Sassari, Sardegna, Italy
| | - Giacomo Indiveri
- SynSense, Thurgauerstrasse 40, 8050, Zurich, Switzerland
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Dylan R Muir
- SynSense, Thurgauerstrasse 40, 8050, Zurich, Switzerland.
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Risi N, Aimar A, Donati E, Solinas S, Indiveri G. A Spike-Based Neuromorphic Architecture of Stereo Vision. Front Neurorobot 2020; 14:568283. [PMID: 33304262 PMCID: PMC7693562 DOI: 10.3389/fnbot.2020.568283] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 10/09/2020] [Indexed: 11/13/2022] Open
Abstract
The problem of finding stereo correspondences in binocular vision is solved effortlessly in nature and yet it is still a critical bottleneck for artificial machine vision systems. As temporal information is a crucial feature in this process, the advent of event-based vision sensors and dedicated event-based processors promises to offer an effective approach to solving the stereo matching problem. Indeed, event-based neuromorphic hardware provides an optimal substrate for fast, asynchronous computation, that can make explicit use of precise temporal coincidences. However, although several biologically-inspired solutions have already been proposed, the performance benefits of combining event-based sensing with asynchronous and parallel computation are yet to be explored. Here we present a hardware spike-based stereo-vision system that leverages the advantages of brain-inspired neuromorphic computing by interfacing two event-based vision sensors to an event-based mixed-signal analog/digital neuromorphic processor. We describe a prototype interface designed to enable the emulation of a stereo-vision system on neuromorphic hardware and we quantify the stereo matching performance with two datasets. Our results provide a path toward the realization of low-latency, end-to-end event-based, neuromorphic architectures for stereo vision.
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Affiliation(s)
- Nicoletta Risi
- Institute of Neuroinformatics, University of Zurich, Eidgenössische Technische Hochschule Zurich, Zurich, Switzerland
| | - Alessandro Aimar
- Institute of Neuroinformatics, University of Zurich, Eidgenössische Technische Hochschule Zurich, Zurich, Switzerland
| | - Elisa Donati
- Institute of Neuroinformatics, University of Zurich, Eidgenössische Technische Hochschule Zurich, Zurich, Switzerland
| | - Sergio Solinas
- Institute of Neuroinformatics, University of Zurich, Eidgenössische Technische Hochschule Zurich, Zurich, Switzerland
| | - Giacomo Indiveri
- Institute of Neuroinformatics, University of Zurich, Eidgenössische Technische Hochschule Zurich, Zurich, Switzerland
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4
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Park DS, Shekhar A, Santucci J, Redel-Traub G, Solinas S, Mintz S, Lin X, Chang EW, Narke D, Xia Y, Goldfarb M, Fishman GI. Ionic Mechanisms of Impulse Propagation Failure in the FHF2-Deficient Heart. Circ Res 2020; 127:1536-1548. [PMID: 32962518 DOI: 10.1161/circresaha.120.317349] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE FHFs (fibroblast growth factor homologous factors) are key regulators of sodium channel (NaV) inactivation. Mutations in these critical proteins have been implicated in human diseases including Brugada syndrome, idiopathic ventricular arrhythmias, and epileptic encephalopathy. The underlying ionic mechanisms by which reduced Nav availability in Fhf2 knockout (Fhf2KO) mice predisposes to abnormal excitability at the tissue level are not well defined. OBJECTIVE Using animal models and theoretical multicellular linear strands, we examined how FHF2 orchestrates the interdependency of sodium, calcium, and gap junctional conductances to safeguard cardiac conduction. METHODS AND RESULTS Fhf2KO mice were challenged by reducing calcium conductance (gCaV) using verapamil or by reducing gap junctional conductance (Gj) using carbenoxolone or by backcrossing into a cardiomyocyte-specific Cx43 (connexin 43) heterozygous background. All conditions produced conduction block in Fhf2KO mice, with Fhf2 wild-type (Fhf2WT) mice showing normal impulse propagation. To explore the ionic mechanisms of block in Fhf2KO hearts, multicellular linear strand models incorporating FHF2-deficient Nav inactivation properties were constructed and faithfully recapitulated conduction abnormalities seen in mutant hearts. The mechanisms of conduction block in mutant strands with reduced gCaV or diminished Gj are very different. Enhanced Nav inactivation due to FHF2 deficiency shifts dependence onto calcium current (ICa) to sustain electrotonic driving force, axial current flow, and action potential (AP) generation from cell-to-cell. In the setting of diminished Gj, slower charging time from upstream cells conspires with accelerated Nav inactivation in mutant strands to prevent sufficient downstream cell charging for AP propagation. CONCLUSIONS FHF2-dependent effects on Nav inactivation ensure adequate sodium current (INa) reserve to safeguard against numerous threats to reliable cardiac impulse propagation.
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Affiliation(s)
- David S Park
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine
| | - Akshay Shekhar
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine.,Regeneron Pharmaceuticals, Tarrytown, NY (A.S.)
| | - John Santucci
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine
| | - Gabriel Redel-Traub
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine
| | - Sergio Solinas
- University of Zurich, Institute of Neuroinformatics, Switzerland (S.S.).,Hunter College of City University, Department of Biological Sciences, New York (S.S., M.G.)
| | - Shana Mintz
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine
| | - Xianming Lin
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine
| | - Ernest Whanwook Chang
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine
| | - Deven Narke
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine
| | - Yuhe Xia
- Department of Population Health (Y.X.), New York University School of Medicine
| | - Mitchell Goldfarb
- Hunter College of City University, Department of Biological Sciences, New York (S.S., M.G.)
| | - Glenn I Fishman
- The Leon H. Charney Division of Cardiology (D.S.P., A.S., J.S., G.R.-T., S.M., X.L., E.W.C., D.N., G.I.F.), New York University School of Medicine
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Gleeson P, Cantarelli M, Marin B, Quintana A, Earnshaw M, Sadeh S, Piasini E, Birgiolas J, Cannon RC, Cayco-Gajic NA, Crook S, Davison AP, Dura-Bernal S, Ecker A, Hines ML, Idili G, Lanore F, Larson SD, Lytton WW, Majumdar A, McDougal RA, Sivagnanam S, Solinas S, Stanislovas R, van Albada SJ, van Geit W, Silver RA. Open Source Brain: A Collaborative Resource for Visualizing, Analyzing, Simulating, and Developing Standardized Models of Neurons and Circuits. Neuron 2019; 103:395-411.e5. [PMID: 31201122 PMCID: PMC6693896 DOI: 10.1016/j.neuron.2019.05.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 03/04/2019] [Accepted: 05/09/2019] [Indexed: 02/07/2023]
Abstract
Computational models are powerful tools for exploring the properties of complex biological systems. In neuroscience, data-driven models of neural circuits that span multiple scales are increasingly being used to understand brain function in health and disease. But their adoption and reuse has been limited by the specialist knowledge required to evaluate and use them. To address this, we have developed Open Source Brain, a platform for sharing, viewing, analyzing, and simulating standardized models from different brain regions and species. Model structure and parameters can be automatically visualized and their dynamical properties explored through browser-based simulations. Infrastructure and tools for collaborative interaction, development, and testing are also provided. We demonstrate how existing components can be reused by constructing new models of inhibition-stabilized cortical networks that match recent experimental results. These features of Open Source Brain improve the accessibility, transparency, and reproducibility of models and facilitate their reuse by the wider community.
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Affiliation(s)
- Padraig Gleeson
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Matteo Cantarelli
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK; MetaCell Limited, Oxford, UK
| | - Boris Marin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK; Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, Santo André, Brazil
| | - Adrian Quintana
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Matt Earnshaw
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Sadra Sadeh
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Eugenio Piasini
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK; Computational Neuroscience Initiative and Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Justas Birgiolas
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | | | - N Alex Cayco-Gajic
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Sharon Crook
- School of Life Sciences, Arizona State University, Tempe, AZ, USA; School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, USA
| | - Andrew P Davison
- Unité de Neuroscience, Information et Complexité, Centre National de la Recherche Scientifique, Paris, France
| | | | - András Ecker
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK; Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Michael L Hines
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | | | - Frederic Lanore
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | | | - William W Lytton
- SUNY Downstate Medical Center and Kings County Hospital, Brooklyn, NY, USA
| | | | - Robert A McDougal
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA; Center for Medical Informatics, Yale University, New Haven, CT, USA
| | | | - Sergio Solinas
- Department of Biomedical Science, University of Sassari, Sassari, Italy; Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Rokas Stanislovas
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Sacha J van Albada
- Institute of Neuroscience and Medicine (INM-6), Institute for Advanced Simulation (IAS-6) and JARA-Institut Brain Structure-Function Relationships (INM-10), Jülich Research Centre, Jülich, Germany
| | - Werner van Geit
- Blue Brain Project, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - R Angus Silver
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
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Mariani G, Solinas S, Pasqualetti D, Ghirardini A, Verani P, Buttó S, Lopez M, Moretti T. Induction of Immunotolerance in Hemophilia for High Titre Inhibitor Eradication: A Long-Term Follow-Up. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1651013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThree hemophiliacs with high titre inhibitor were treated with a medium-high FVIII dose schedule (100 IU/kg bw daily) with the aim of inducing the immunotolerance. These patients were followed-up extensively concerning their immunological status and HIV serology. In all of them the inhibitor disappeared and normal FVIII kinetics were obtained after 22, 15 and 29 months. After eradication of the inhibitor, no recurrence took place in any of the patients. All the patients were HIV Ab positive before the beginning of the treatment. In one of them CD4+ cells fell progessively 32 months after the treatment was started, a fullblown AIDS showed up, and the patient died 5½ years after the beginning of the treatment. In the second and third patient the CD4+ cells varied widely but remained >400/μl during the whole immunotolerance treatment. The latter two patients are AIDS and ARC free so far, but patient No. 2 developed a mild-to-severe thrombocytopenia.Considering the high cost of the treatment and the possibility that such an intensive administration of FVIII concentrates might worsen the immunological status of patients, this therapeutic procedure should only be applied with caution.
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Affiliation(s)
- G Mariani
- Dipartimento di Biopatologia Umana, Sezione di Ematologia Universita' di Roma “La Sapienza”, Roma, Italy
| | - S Solinas
- Dipartimento di Biopatologia Umana, Sezione di Ematologia Universita' di Roma “La Sapienza”, Roma, Italy
| | - D Pasqualetti
- Dipartimento di Biopatologia Umana, Sezione di Ematologia Universita' di Roma “La Sapienza”, Roma, Italy
| | - A Ghirardini
- Dipartimento di Biopatologia Umana, Sezione di Ematologia Universita' di Roma “La Sapienza”, Roma, Italy
| | - P Verani
- Laboratorio di Virologia, Instituto Superiore di Sanita' Roma, Italy
| | - S Buttó
- Laboratorio di Virologia, Instituto Superiore di Sanita' Roma, Italy
| | - M Lopez
- Dipartimento di Biopatologia Umana, Sezione di Ematologia Universita' di Roma “La Sapienza”, Roma, Italy
| | - T Moretti
- Dipartimento di Biopatologia Umana, Sezione di Ematologia Universita' di Roma “La Sapienza”, Roma, Italy
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Ghirardini A, Mariani G, lacopino G, Tirindelli MC, Solinas S, Moretti T. Concentrated DDAVP: Further Improvement in the Management of Mild Factor VIII Deficiencies. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1646011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThis study was carried out to evaluate the pharmacological efficacy of a new concentrated 1 Deamino - (8-D-arginine) - vasopressin (DDAVP) preparation. Concentrated DDAVP (C- DDAVP), (40 μg/mL) was given subcutaneously (s.c.) in hemophilia and von Willebrand Disease (vWD), and the response was evaluated in terms of factor VIII/vWF (VUI/von Willebrand Factor) complex response. This response was also compared to that obtained using the currently available commercial preparation (4 μg/mL) given either s.c. or intravenously (i. v.). The maximal f. VIII response after s.c. C-DDAVP was reached one hour after the injection (x:3.6 times the resting values) with an average decline of 15% at two hours. The response to s.c. C- DDAVP in patients with hemophilia was slightly better than thut obtained with the diluted brand, but the difference did not reach any statistical significance even when the schedules were compared in the same patients. In type I (placed normal subtype) vWD, a higher response in terms of factor VIII :C increase in comparison with hemophiliacs was obtained. Doth Ristocetin cofactor activity (RiCof) and bleeding time responded to this vasopressin analogue, when administered subcutaneously.
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Affiliation(s)
- A Ghirardini
- The Department of Human Biopathology, Section of Hematology, University of Roma “La Sapienza”, Rome, Italy
| | - G Mariani
- The Department of Human Biopathology, Section of Hematology, University of Roma “La Sapienza”, Rome, Italy
| | - G lacopino
- The Department of Human Biopathology, Section of Hematology, University of Roma “La Sapienza”, Rome, Italy
| | - M C Tirindelli
- The Department of Human Biopathology, Section of Hematology, University of Roma “La Sapienza”, Rome, Italy
| | - S Solinas
- The Department of Human Biopathology, Section of Hematology, University of Roma “La Sapienza”, Rome, Italy
| | - T Moretti
- The Department of Human Biopathology, Section of Hematology, University of Roma “La Sapienza”, Rome, Italy
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Newton AJH, Seidenstein AH, McDougal RA, Pérez-Cervera A, Huguet G, M-Seara T, Haimerl C, Angulo-Garcia D, Torcini A, Cossart R, Malvache A, Skiker K, Maouene M, Ragognetti G, Lorusso L, Viggiano A, Marcelli A, Senatore R, Parziale A, Stramaglia S, Pellicoro M, Angelini L, Amico E, Aerts H, Cortés J, Laureys S, Marinazzo D, Stramaglia S, Bassez I, Faes L, Almgren H, Razi A, Van de Steen F, Krebs R, Aerts H, Kanari L, Dlotko P, Scolamiero M, Levi R, Shillcock J, de Kock CP, Hess K, Markram H, Ly C, Marsat G, Gillespie T, Sandström M, Abrams M, Grethe JS, Martone M, De Gernier R, Solinas S, Rössert C, Haelterman M, Massar S, Pasquale V, Pastore VP, Martinoia S, Massobrio P, Capone C, Tort-Colet N, Sanchez-Vives MV, Mattia M, Almasi A, Cloherty SL, Grayden DB, Wong YT, Ibbotson MR, Meffin H, Prince LY, Tsaneva-Atanasova K, Mellor JR, Mazzoni A, Rosa M, Carpaneto J, Romito LM, Priori A, Micera S, Migliore R, Lupascu CA, Franchina F, Bologna LL, Romani A, Saray S, Van Geit W, Káli S, Thomson A, Mercer A, Lange S, Falck J, Muller E, Schürmann F, Todorov D, Capps R, Barnett W, Molkov Y, Devalle F, Pazó D, Montbrió E, Mochol G, Azab H, Hayden BY, Moreno-Bote R, Balasubramani PP, Chakravarthy SV, Muddapu VR, Gheorghiu MD, Mimica B, Withlock J, Mureșan RC, Zick JL, Schultz K, Blackman RK, Chafee MV, Netoff TI, Roberts N, Nagaraj V, Lamperski A, Netoff TI, Grado LL, Johnson MD, Darrow DP, Lonardoni D, Amin H, Di Marco S, Maccione A, Berdondini L, Nieus T, Stimberg M, Goodman DFM, Nowotny T, Koren V, Dragoi V, Obermayer K, Castro S, Fernandez M, El-Deredy W, Xu K, Maidana JP, Orio P, Chen W, Hepburn I, Casalegno F, Devresse A, Ovcharenko A, Pereira F, Delalondre F, De Schutter E, Bratby P, Gallimore AR, Klingbeil G, Zamora C, Zang Y, Crotty P, Palmerduca E, Antonietti A, Casellato C, Erö C, D’Angelo E, Gewaltig MO, Pedrocchi A, Bytschok I, Dold D, Schemmel J, Meier K, Petrovici MA, Shen HA, Surace SC, Pfister JP, Lefebvre B, Marre O, Yger P, Papoutsi A, Park J, Ash R, Smirnakis S, Poirazi P, Felix RA, Dimitrov AG, Portfors C, Daun S, Toth TI, Jędrzejewska-Szmek J, Kabbani N, Blackwel KT, Moezzi B, Schaworonkow N, Plogmacher L, Goldsworthy MR, Hordacre B, McDonnell MD, Iannella N, Ridding MC, Triesch J, Maex R, Safaryan K, Steuber V, Tang R, Tang YY, Verveyko DV, Brazhe AR, Verisokin AY, Postnov DE, Günay C, Panuccio G, Giugliano M, Prinz AA, Varona P, Rabinovich MI, Denham J, Ranner T, Cohen N, Reva M, Rebola N, Kirizs T, Nusser Z, DiGregorio D, Mavritsaki E, Rentzelas P, Ukani NH, Tomkins A, Yeh CH, Bruning W, Fenichel AL, Zhou Y, Huang YC, Florescu D, Ortiz CL, Richmond P, Lo CC, Coca D, Chiang AS, Lazar AA, Moezzi B, Creaser JL, Lin C, Ashwin P, Brown JT, Ridler T, Levenstein D, Watson BO, Buzsáki G, Rinzel J, Curtu R, Nguyen A, Assadzadeh S, Robinson PA, Sanz-Leon P, Forlim CG, de Almeida LOB, Pinto RD, Rodríguez FB, Lareo Á, Forlim CG, Rodríguez FB, Montero A, Mosqueiro T, Huerta R, Rodriguez FB, Changoluisa V, Rodriguez FB, Cordeiro VL, Ceballos CC, Kamiji NL, Roque AC, Lytton WW, Knox A, Rosenthal JJC, Daun S, Popovych S, Liu L, Wang BA, Tóth TI, Grefkes C, Fink GR, Rosjat N, Perez-Trujillo A, Espinal A, Sotelo-Figueroa MA, Cruz-Aceves I, Rostro-Gonzalez H, Zapotocky M, Hoskovcová M, Kopecká J, Ulmanová O, Růžička E, Gärtner M, Duvarci S, Roeper J, Schneider G, Albert S, Schmack K, Remme M, Schreiber S, Migliore M, Lupascu CA, Bologna LL, Antonel SM, Courcol JD, Schürmann F, Çelikok SU, Navarro-López EM, Şengör NS, Elibol R, Sengor NS, Özdemir MY, Li T, Arleo A, Sheynikhovich D, Nakamura A, Shimono M, Song Y, Park S, Choi I, Jeong J, Shin HS, Sadeh S, Gleeson P, Angus Silver R, Chatzikalymniou AP, Skinner FK, Sanchez-Rodriguez LM, Sotero RC, Hertäg L, Mackwood O, Sprekeler H, Puhlmann S, Weber SN, Higgins D, Naumann LB, Weber SN, Iyer R, Mihalas S, Ticcinelli V, Stankovski T, McClintock PVE, Stefanovska A, Janjić P, Solev D, Seifert G, Kocarev L, Steinhäuser C, Salmasi M, Glasauer S, Stemmler M, Zhang D, Zhang C, Stepanyants A, Goncharenko J, Kros L, Davey N, de Zeeuw C, Hoebeek F, Sinha A, Adams R, Schmuker M, Psarrou M, Schilstra M, Torben-Nielsen B, Metzner C, Schweikard A, Mäki-Marttunen T, Zurowski B, Marinazzo D, Faes L, Stramaglia S, Jordan HOC, Stringer SM, Gajewska-Dendek E, Suffczyński P, Tam N, Zouridakis G, Pollonini L, Tang YY, Asl MM, Valizadeh A, Tass PA, Nold A, Fan W, Konrad S, Endle H, Vogt J, Tchumatchenko T, Herpich J, Tetzlaff C, Luboeinski J, Nachstedt T, Ciba M, Bahmer A, Thielemann C, Kuebler ES, Tauskela JS, Thivierge JP, Bakker R, García-Amado M, Evangelio M, Clascá F, Tiesinga P, Buckley CL, Toyoizumi T, Dubreuil AM, Monasson R, Treves A, Spalla D, Rosay S, Kleberg FI, Wong W, de Oliveira Floriano B, Matsuo T, Uchida T, Dibenedetto D, Uludağ K, Goodarzinick A, Schmidt M, Hilgetag CC, Diesmann M, van Albada SJ, Fauth M, van Rossum M, Reyes-Sánchez M, Amaducci R, Muñiz C, Varona P, Elices I, Arroyo D, Levi R, Cohen B, Chow C, Vattikuti S, Bertolotti E, Burioni R, di Volo M, Vezzani A, Menzat B, Vogels TP, Wagatsuma N, Saha S, Kapoor R, Kerr R, Wagner J, del Molino LCG, Yang GR, Mejias JF, Wang XJ, Song H, Goodliffe J, Luebke J, Weaver CM, Thomas J, Sinha N, Shaju N, Maszczyk T, Jin J, Cash SS, Dauwels J, Brandon Westover M, Karimian M, Moerel M, De Weerd P, Burwick T, Westra RL, Abeysuriya R, Hadida J, Sotiropoulos S, Jbabdi S, Woolrich M, Bensmail C, Wrobel B, Zhou X, Ji Z, Liu X, Xia Y, Wu S, Wang X, Zhang M, Wu S, Ofer N, Shefi O, Yaari G, Carnevale T, Majumdar A, Sivagnanam S, Yoshimoto K, Smirnova EY, Amakhin DV, Malkin SL, Zaitsev AV, Chizhov AV, Zaleshina M, Zaleshin A, Barranca VJ, Zhu G, Skilling QM, Maruyama D, Ognjanovski N, Aton SJ, Zochowski M, Wu J, Aton S, Rich S, Booth V, Budak M, Dura-Bernal S, Neymotin SA, Suter BA, Shepherd GMG, Felton MA, Yu AB, Boothe DL, Oie KS, Franaszczuk PJ, Shuvaev SA, Başerdem B, Zador A, Koulakov AA, López-Madrona VJ, Pereda E, Mirasso CR, Canals S, Masoli S, Rongala UB, Mazzoni A, Spanne A, Jorntell H, Oddo CM, Vartanov AV, Neklyudova AK, Kozlovskiy SA, Kiselnikov AA, Marakshina JA, Teleńczuk M, Teleńczuk B, Destexhe A, Kuokkanen PT, Kraemer A, McColgan T, Carr CE, Kempter R. 26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3. BMC Neurosci 2017. [PMCID: PMC5592441 DOI: 10.1186/s12868-017-0372-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Dover K, Marra C, Solinas S, Popovic M, Subramaniyam S, Zecevic D, D'Angelo E, Goldfarb M. FHF-independent conduction of action potentials along the leak-resistant cerebellar granule cell axon. Nat Commun 2016; 7:12895. [PMID: 27666389 PMCID: PMC5052690 DOI: 10.1038/ncomms12895] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 08/11/2016] [Indexed: 12/31/2022] Open
Abstract
Neurons in vertebrate central nervous systems initiate and conduct sodium action potentials in distinct subcellular compartments that differ architecturally and electrically. Here, we report several unanticipated passive and active properties of the cerebellar granule cell's unmyelinated axon. Whereas spike initiation at the axon initial segment relies on sodium channel (Nav)-associated fibroblast growth factor homologous factor (FHF) proteins to delay Nav inactivation, distal axonal Navs show little FHF association or FHF requirement for high-frequency transmission, velocity and waveforms of conducting action potentials. In addition, leak conductance density along the distal axon is estimated as <1% that of somatodendritic membrane. The faster inactivation rate of FHF-free Navs together with very low axonal leak conductance serves to minimize ionic fluxes and energetic demand during repetitive spike conduction and at rest. The absence of FHFs from Navs at nodes of Ranvier in the central nervous system suggests a similar mechanism of current flux minimization along myelinated axons. FHFs are known to regulate voltage-gated sodium channels (NaVs). Here, the authors compare the role of FHFs in cerebellar granule cell propagation, and find NaVs in the distal axon function independently of FHFs, allowing for faster inactivation rates and reducing energy demands during repetitive spiking.
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Affiliation(s)
- Katarzyna Dover
- Department of Biological Sciences, Hunter College of City University, 695 Park Avenue, New York, New York 10065, USA.,Graduate Center of City University, Molecular, Cellular and Developmental Biology Subprogram, 365 Fifth Avenue, New York, New York 10016, USA
| | - Christopher Marra
- Department of Biological Sciences, Hunter College of City University, 695 Park Avenue, New York, New York 10065, USA.,Graduate Center of City University, Neuroscience Subprogram, 365 Fifth Avenue, New York, New York 10016, USA
| | - Sergio Solinas
- Brain Connectivity Center, C. Mondino National Neurological Institute, Via Forlanini 6, Pavia 27100, Italy
| | - Marko Popovic
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA
| | - Sathyaa Subramaniyam
- Department of Brain and Behavioral Science, University of Pavia, Via Forlanini 6, Pavia 27100, Italy
| | - Dejan Zecevic
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut 06510, USA
| | - Egidio D'Angelo
- Brain Connectivity Center, C. Mondino National Neurological Institute, Via Forlanini 6, Pavia 27100, Italy.,Department of Brain and Behavioral Science, University of Pavia, Via Forlanini 6, Pavia 27100, Italy
| | - Mitchell Goldfarb
- Department of Biological Sciences, Hunter College of City University, 695 Park Avenue, New York, New York 10065, USA.,Graduate Center of City University, Neuroscience Subprogram, 365 Fifth Avenue, New York, New York 10016, USA
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Cattani A, Solinas S, Canuto C. A Hybrid Model for the Computationally-Efficient Simulation of the Cerebellar Granular Layer. Front Comput Neurosci 2016; 10:30. [PMID: 27148027 PMCID: PMC4837690 DOI: 10.3389/fncom.2016.00030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 03/24/2016] [Indexed: 11/13/2022] Open
Abstract
The aim of the present paper is to efficiently describe the membrane potential dynamics of neural populations formed by species having a high density difference in specific brain areas. We propose a hybrid model whose main ingredients are a conductance-based model (ODE system) and its continuous counterpart (PDE system) obtained through a limit process in which the number of neurons confined in a bounded region of the brain tissue is sent to infinity. Specifically, in the discrete model, each cell is described by a set of time-dependent variables, whereas in the continuum model, cells are grouped into populations that are described by a set of continuous variables. Communications between populations, which translate into interactions among the discrete and the continuous models, are the essence of the hybrid model we present here. The cerebellum and cerebellum-like structures show in their granular layer a large difference in the relative density of neuronal species making them a natural testing ground for our hybrid model. By reconstructing the ensemble activity of the cerebellar granular layer network and by comparing our results to a more realistic computational network, we demonstrate that our description of the network activity, even though it is not biophysically detailed, is still capable of reproducing salient features of neural network dynamics. Our modeling approach yields a significant computational cost reduction by increasing the simulation speed at least 270 times. The hybrid model reproduces interesting dynamics such as local microcircuit synchronization, traveling waves, center-surround, and time-windowing.
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Affiliation(s)
- Anna Cattani
- Laboratory of Neural Computation, Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia Rovereto, Italy
| | - Sergio Solinas
- Department of Brain and Behavioural Science, University of Pavia Pavia, Italy
| | - Claudio Canuto
- Department of Mathematical Sciences, Polytechnic University of Turin Torino, Italy
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Mapelli L, Solinas S, D'Angelo E. Corrigendum: Integration and regulation of glomerular inhibition in the cerebellar granular layer circuit. Front Cell Neurosci 2016; 10:31. [PMID: 26909024 PMCID: PMC4754449 DOI: 10.3389/fncel.2016.00031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 01/29/2016] [Indexed: 11/13/2022] Open
Abstract
[This corrects the article on p. 55 in vol. 8, PMID: 24616663.].
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Affiliation(s)
- Lisa Mapelli
- Brain and Behavioral Sciences, Neurophysiology Unit, University of Pavia Pavia, Italy
| | - Sergio Solinas
- Brain and Behavioral Sciences, Neurophysiology Unit, University of Pavia Pavia, Italy
| | - Egidio D'Angelo
- Brain and Behavioral Sciences, Neurophysiology Unit, University of PaviaPavia, Italy; Brain Connectivity Center, C. Mondino National Neurological InstitutePavia, Italy
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Masoli S, Solinas S, D'Angelo E. Action potential processing in a detailed Purkinje cell model reveals a critical role for axonal compartmentalization. Front Cell Neurosci 2015; 9:47. [PMID: 25759640 PMCID: PMC4338753 DOI: 10.3389/fncel.2015.00047] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/30/2015] [Indexed: 12/02/2022] Open
Abstract
The Purkinje cell (PC) is among the most complex neurons in the brain and plays a critical role for cerebellar functioning. PCs operate as fast pacemakers modulated by synaptic inputs but can switch from simple spikes to complex bursts and, in some conditions, show bistability. In contrast to original works emphasizing dendritic Ca-dependent mechanisms, recent experiments have supported a primary role for axonal Na-dependent processing, which could effectively regulate spike generation and transmission to deep cerebellar nuclei (DCN). In order to account for the numerous ionic mechanisms involved (at present including Nav1.6, Cav2.1, Cav3.1, Cav3.2, Cav3.3, Kv1.1, Kv1.5, Kv3.3, Kv3.4, Kv4.3, KCa1.1, KCa2.2, KCa3.1, Kir2.x, HCN1), we have elaborated a multicompartmental model incorporating available knowledge on localization and gating of PC ionic channels. The axon, including initial segment (AIS) and Ranvier nodes (RNs), proved critical to obtain appropriate pacemaking and firing frequency modulation. Simple spikes initiated in the AIS and protracted discharges were stabilized in the soma through Na-dependent mechanisms, while somato-dendritic Ca channels contributed to sustain pacemaking and to generate complex bursting at high discharge regimes. Bistability occurred only following Na and Ca channel down-regulation. In addition, specific properties in RNs K currents were required to limit spike transmission frequency along the axon. The model showed how organized electroresponsive functions could emerge from the molecular complexity of PCs and showed that the axon is fundamental to complement ionic channel compartmentalization enabling action potential processing and transmission of specific spike patterns to DCN.
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Affiliation(s)
- Stefano Masoli
- Department of Brain and Behavioral Science, University of Pavia Pavia, Italy
| | - Sergio Solinas
- Brain Connectivity Center, Istituto Neurologico IRCCS C. Mondino Pavia, Italy
| | - Egidio D'Angelo
- Department of Brain and Behavioral Science, University of Pavia Pavia, Italy ; Brain Connectivity Center, Istituto Neurologico IRCCS C. Mondino Pavia, Italy
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Mapelli L, Solinas S, D'Angelo E. Corrigendum: Integration and regulation of glomerular inhibition in the cerebellar granular layer circuit. Front Cell Neurosci 2014. [PMCID: PMC4202706 DOI: 10.3389/fncel.2014.00342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Lisa Mapelli
- Brain Connectivity Center, C. Mondino National Neurological InstitutePavia, Italy
- Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy
| | - Sergio Solinas
- Brain Connectivity Center, C. Mondino National Neurological InstitutePavia, Italy
- *Correspondence:
| | - Egidio D'Angelo
- Brain Connectivity Center, C. Mondino National Neurological InstitutePavia, Italy
- Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy
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Rössert C, Solinas S, D'Angelo E, Dean P, Porrill J. Model cerebellar granule cells can faithfully transmit modulated firing rate signals. Front Cell Neurosci 2014; 8:304. [PMID: 25352777 PMCID: PMC4195316 DOI: 10.3389/fncel.2014.00304] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 09/09/2014] [Indexed: 12/02/2022] Open
Abstract
A crucial assumption of many high-level system models of the cerebellum is that information in the granular layer is encoded in a linear manner. However, granule cells are known for their non-linear and resonant synaptic and intrinsic properties that could potentially impede linear signal transmission. In this modeling study we analyse how electrophysiological granule cell properties and spike sampling influence information coded by firing rate modulation, assuming no signal-related, i.e., uncorrelated inhibitory feedback (open-loop mode). A detailed one-compartment granule cell model was excited in simulation by either direct current or mossy-fiber synaptic inputs. Vestibular signals were represented as tonic inputs to the flocculus modulated at frequencies up to 20 Hz (approximate upper frequency limit of vestibular-ocular reflex, VOR). Model outputs were assessed using estimates of both the transfer function, and the fidelity of input-signal reconstruction measured as variance-accounted-for. The detailed granule cell model with realistic mossy-fiber synaptic inputs could transmit information faithfully and linearly in the frequency range of the vestibular-ocular reflex. This was achieved most simply if the model neurons had a firing rate at least twice the highest required frequency of modulation, but lower rates were also adequate provided a population of neurons was utilized, especially in combination with push-pull coding. The exact number of neurons required for faithful transmission depended on the precise values of firing rate and noise. The model neurons were also able to combine excitatory and inhibitory signals linearly, and could be replaced by a simpler (modified) integrate-and-fire neuron in the case of high tonic firing rates. These findings suggest that granule cells can in principle code modulated firing-rate inputs in a linear manner, and are thus consistent with the high-level adaptive-filter model of the cerebellar microcircuit.
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Affiliation(s)
| | - Sergio Solinas
- Brain Connectivity Center, Istituto Neurologico Istituto di Ricovero e Cura a Carattere Scientifico C. Mondino Pavia, Italy
| | - Egidio D'Angelo
- Brain Connectivity Center, Istituto Neurologico Istituto di Ricovero e Cura a Carattere Scientifico C. Mondino Pavia, Italy ; Laboratory of Neurophysiology, Department of Brain and Behavioural Sciences, University of Pavia Pavia, Italy
| | - Paul Dean
- Department of Psychology, University of Sheffield Sheffield, UK
| | - John Porrill
- Department of Psychology, University of Sheffield Sheffield, UK
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Subramaniyam S, Solinas S, Perin P, Locatelli F, Masetto S, D'Angelo E. Computational modeling predicts the ionic mechanism of late-onset responses in unipolar brush cells. Front Cell Neurosci 2014; 8:237. [PMID: 25191224 PMCID: PMC4138490 DOI: 10.3389/fncel.2014.00237] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 07/27/2014] [Indexed: 11/29/2022] Open
Abstract
Unipolar Brush Cells (UBCs) have been suggested to play a critical role in cerebellar functioning, yet the corresponding cellular mechanisms remain poorly understood. UBCs have recently been reported to generate, in addition to early-onset glutamate receptor-dependent synaptic responses, a late-onset response (LOR) composed of a slow depolarizing ramp followed by a spike burst (Locatelli et al., 2013). The LOR activates as a consequence of synaptic activity and involves an intracellular cascade modulating H- and TRP-current gating. In order to assess the LOR mechanisms, we have developed a UBC multi-compartmental model (including soma, dendrite, initial segment, and axon) incorporating biologically realistic representations of ionic currents and a cytoplasmic coupling mechanism regulating TRP and H channel gating. The model finely reproduced UBC responses to current injection, including a burst triggered by a low-threshold spike (LTS) sustained by CaLVA currents, a persistent discharge sustained by CaHVA currents, and a rebound burst following hyperpolarization sustained by H- and CaLVA-currents. Moreover, the model predicted that H- and TRP-current regulation was necessary and sufficient to generate the LOR and its dependence on the intensity and duration of mossy fiber activity. Therefore, the model showed that, using a basic set of ionic channels, UBCs generate a rich repertoire of bursts, which could effectively implement tunable delay-lines in the local microcircuit.
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Affiliation(s)
- Sathyaa Subramaniyam
- Neurophysiology Unit, Department of Brain and Behavioral Science, University of Pavia Pavia, Italy ; Consorzio Interuniversitario per le Scienze Fisiche della Materia (CNISM) Pavia, Italy
| | - Sergio Solinas
- Neurophysiology Unit, Brain Connectivity Center, Istituto Neurologico IRCCS C. Mondino Pavia, Italy
| | - Paola Perin
- Neurophysiology Unit, Department of Brain and Behavioral Science, University of Pavia Pavia, Italy
| | - Francesca Locatelli
- Neurophysiology Unit, Department of Brain and Behavioral Science, University of Pavia Pavia, Italy
| | - Sergio Masetto
- Neurophysiology Unit, Department of Brain and Behavioral Science, University of Pavia Pavia, Italy
| | - Egidio D'Angelo
- Neurophysiology Unit, Department of Brain and Behavioral Science, University of Pavia Pavia, Italy ; Neurophysiology Unit, Brain Connectivity Center, Istituto Neurologico IRCCS C. Mondino Pavia, Italy
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D'Angelo E, Solinas S, Garrido J, Casellato C, Pedrocchi A, Mapelli J, Gandolfi D, Prestori F. Realistic modeling of neurons and networks: towards brain simulation. Funct Neurol 2014; 28:153-66. [PMID: 24139652 DOI: 10.11138/fneur/2013.28.3.153] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Realistic modeling is a new advanced methodology for investigating brain functions. Realistic modeling is based on a detailed biophysical description of neurons and synapses, which can be integrated into microcircuits. The latter can, in turn, be further integrated to form large-scale brain networks and eventually to reconstruct complex brain systems. Here we provide a review of the realistic simulation strategy and use the cerebellar network as an example. This network has been carefully investigated at molecular and cellular level and has been the object of intense theoretical investigation. The cerebellum is thought to lie at the core of the forward controller operations of the brain and to implement timing and sensory prediction functions. The cerebellum is well described and provides a challenging field in which one of the most advanced realistic microcircuit models has been generated. We illustrate how these models can be elaborated and embedded into robotic control systems to gain insight into how the cellular properties of cerebellar neurons emerge in integrated behaviors. Realistic network modeling opens up new perspectives for the investigation of brain pathologies and for the neurorobotic field.
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Mapelli L, Solinas S, D'Angelo E. Integration and regulation of glomerular inhibition in the cerebellar granular layer circuit. Front Cell Neurosci 2014; 8:55. [PMID: 24616663 PMCID: PMC3933946 DOI: 10.3389/fncel.2014.00055] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/06/2014] [Indexed: 11/26/2022] Open
Abstract
Inhibitory synapses can be organized in different ways and be regulated by a multitude of mechanisms. One of the best known examples is provided by the inhibitory synapses formed by Golgi cells onto granule cells in the cerebellar glomeruli. These synapses are GABAergic and inhibit granule cells through two main mechanisms, phasic and tonic. The former is based on vesicular neurotransmitter release, the latter on the establishment of tonic γ-aminobutyric acid (GABA) levels determined by spillover and regulation of GABA uptake. The mechanisms of post-synaptic integration have been clarified to a considerable extent and have been shown to differentially involve α1 and α6 subunit-containing GABA-A receptors. Here, after reviewing the basic mechanisms of GABAergic transmission in the cerebellar glomeruli, we examine how inhibition controls signal transfer at the mossy fiber-granule cell relay. First of all, we consider how vesicular release impacts on signal timing and how tonic GABA levels control neurotransmission gain. Then, we analyze the integration of these inhibitory mechanisms within the granular layer network. Interestingly, it turns out that glomerular inhibition is just one element in a large integrated signaling system controlled at various levels by metabotropic receptors. GABA-B receptor activation by ambient GABA regulates glutamate release from mossy fibers through a pre-synaptic cross-talk mechanisms, GABA release through pre-synaptic auto-receptors, and granule cell input resistance through post-synaptic receptor activation and inhibition of a K inward-rectifier current. Metabotropic glutamate receptors (mGluRs) control GABA release from Golgi cell terminals and Golgi cell input resistance and autorhythmic firing. This complex set of mechanisms implements both homeostatic and winner-take-all processes, providing the basis for fine-tuning inhibitory neurotransmission and for optimizing signal transfer through the cerebellar cortex.
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Affiliation(s)
- Lisa Mapelli
- Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy
- Brain Connectivity Center, C. Mondino National Neurological InstitutePavia, Italy
| | - Sergio Solinas
- Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy
- Brain Connectivity Center, C. Mondino National Neurological InstitutePavia, Italy
| | - Egidio D'Angelo
- Department of Brain and Behavioral Sciences, University of PaviaPavia, Italy
- Brain Connectivity Center, C. Mondino National Neurological InstitutePavia, Italy
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Subramaniyam S, Perin P, Locatelli F, Masetto S, Solinas S, D'Angelo E. The mechanisms of late-onset synaptic responses in a realistic model of Unipolar Brush Cells. BMC Neurosci 2013. [PMCID: PMC3704851 DOI: 10.1186/1471-2202-14-s1-p79] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Masoli S, Solinas S, D'Angelo E. The intrinsic and synaptic responsiveness of a new realistic Purkinje cell model. BMC Neurosci 2013. [PMCID: PMC3704860 DOI: 10.1186/1471-2202-14-s1-p80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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D’Angelo E, Solinas S, Garrido J, Casellato C, Pedrocchi A, Mapelli J, Gandolfi D, Prestori F. Realistic modeling of neurons and networks: towards brain simulation. Funct Neurol 2013; 28:153-66. [PMID: 24139652 PMCID: PMC3812748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Realistic modeling is a new advanced methodology for investigating brain functions. Realistic modeling is based on a detailed biophysical description of neurons and synapses, which can be integrated into microcircuits. The latter can, in turn, be further integrated to form large-scale brain networks and eventually to reconstruct complex brain systems. Here we provide a review of the realistic simulation strategy and use the cerebellar network as an example. This network has been carefully investigated at molecular and cellular level and has been the object of intense theoretical investigation. The cerebellum is thought to lie at the core of the forward controller operations of the brain and to implement timing and sensory prediction functions. The cerebellum is well described and provides a challenging field in which one of the most advanced realistic microcircuit models has been generated. We illustrate how these models can be elaborated and embedded into robotic control systems to gain insight into how the cellular properties of cerebellar neurons emerge in integrated behaviors. Realistic network modeling opens up new perspectives for the investigation of brain pathologies and for the neurorobotic field.
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Affiliation(s)
- Egidio D’Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Italy
- Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy
| | - Sergio Solinas
- Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy
| | - Jesus Garrido
- Department of Brain and Behavioral Sciences, University of Pavia, Italy
- CNISM, National Interuniversity Consortium for the Physical Sciences of Matter, Pavia, Italy
| | - Claudia Casellato
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Alessandra Pedrocchi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Jonathan Mapelli
- Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Daniela Gandolfi
- Department of Brain and Behavioral Sciences, University of Pavia, Italy
- Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Francesca Prestori
- Department of Brain and Behavioral Sciences, University of Pavia, Italy
- Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy
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D'Angelo E, Solinas S, Mapelli J, Gandolfi D, Mapelli L, Prestori F. The cerebellar Golgi cell and spatiotemporal organization of granular layer activity. Front Neural Circuits 2013; 7:93. [PMID: 23730271 PMCID: PMC3656346 DOI: 10.3389/fncir.2013.00093] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 04/27/2013] [Indexed: 11/28/2022] Open
Abstract
The cerebellar granular layer has been suggested to perform a complex spatiotemporal reconfiguration of incoming mossy fiber signals. Central to this role is the inhibitory action exerted by Golgi cells over granule cells: Golgi cells inhibit granule cells through both feedforward and feedback inhibitory loops and generate a broad lateral inhibition that extends beyond the afferent synaptic field. This characteristic connectivity has recently been investigated in great detail and been correlated with specific functional properties of these neurons. These include theta-frequency pacemaking, network entrainment into coherent oscillations and phase resetting. Important advances have also been made in terms of determining the membrane and synaptic properties of the neuron, and clarifying the mechanisms of activation by input bursts. Moreover, voltage sensitive dye imaging and multi-electrode array (MEA) recordings, combined with mathematical simulations based on realistic computational models, have improved our understanding of the impact of Golgi cell activity on granular layer circuit computations. These investigations have highlighted the critical role of Golgi cells in: generating dense clusters of granule cell activity organized in center-surround structures, implementing combinatorial operations on multiple mossy fiber inputs, regulating transmission gain, and cut-off frequency, controlling spike timing and burst transmission, and determining the sign, intensity and duration of long-term synaptic plasticity at the mossy fiber-granule cell relay. This review considers recent advances in the field, highlighting the functional implications of Golgi cells for granular layer network computation and indicating new challenges for cerebellar research.
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Affiliation(s)
- Egidio D'Angelo
- Department of Neuroscience, University of PaviaPavia, Italy
- Brain Connectivity Center, IRCCS C. MondinoPavia, Italy
| | | | - Jonathan Mapelli
- Brain Connectivity Center, IRCCS C. MondinoPavia, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Daniela Gandolfi
- Brain Connectivity Center, IRCCS C. MondinoPavia, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio EmiliaModena, Italy
| | - Lisa Mapelli
- Department of Neuroscience, University of PaviaPavia, Italy
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Gandolfi D, Lombardo P, Mapelli J, Solinas S, D'Angelo E. θ-Frequency resonance at the cerebellum input stage improves spike timing on the millisecond time-scale. Front Neural Circuits 2013; 7:64. [PMID: 23596398 PMCID: PMC3622075 DOI: 10.3389/fncir.2013.00064] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 03/20/2013] [Indexed: 11/13/2022] Open
Abstract
The neuronal circuits of the brain are thought to use resonance and oscillations to improve communication over specific frequency bands (Llinas, 1988; Buzsaki, 2006). However, the properties and mechanism of these phenomena in brain circuits remain largely unknown. Here we show that, at the cerebellum input stage, the granular layer (GRL) generates its maximum response at 5-7 Hz both in vivo following tactile sensory stimulation of the whisker pad and in acute slices following mossy fiber bundle stimulation. The spatial analysis of GRL activity performed using voltage-sensitive dye (VSD) imaging revealed 5-7 Hz resonance covering large GRL areas. In single granule cells, resonance appeared as a reorganization of output spike bursts on the millisecond time-scale, such that the first spike occurred earlier and with higher temporal precision and the probability of spike generation increased. Resonance was independent from circuit inhibition, as it persisted with little variation in the presence of the GABAA receptor blocker, gabazine. However, circuit inhibition reduced the resonance area more markedly at 7 Hz. Simulations with detailed computational models suggested that resonance depended on intrinsic granule cells ionic mechanisms: specifically, K slow (M-like) and KA currents acted as resonators and the persistent Na current and NMDA current acted as amplifiers. This form of resonance may play an important role for enhancing coherent spike emission from the GRL when theta-frequency bursts are transmitted by the cerebral cortex and peripheral sensory structures during sensory-motor processing, cognition, and learning.
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Affiliation(s)
- Daniela Gandolfi
- Neurophysiology Unit, Department of Brain and Behavioral Sciences, University of Pavia Pavia, Italy ; Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia Modena, Italy
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Gleeson P, Piasini E, Crook S, Cannon R, Steuber V, Jaeger D, Solinas S, D’Angelo E, Silver RA. The Open Source Brain Initiative: enabling collaborative modelling in computational neuroscience. BMC Neurosci 2012. [PMCID: PMC3403499 DOI: 10.1186/1471-2202-13-s1-o7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Subramaniyam S, Perin P, Solinas S, D’Angelo E. Modeling UBC intrinsic excitability. BMC Neurosci 2011. [PMCID: PMC3240437 DOI: 10.1186/1471-2202-12-s1-p322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Diwakar S, Lombardo P, Solinas S, Naldi G, D'Angelo E. Local field potential modeling predicts dense activation in cerebellar granule cells clusters under LTP and LTD control. PLoS One 2011; 6:e21928. [PMID: 21818278 PMCID: PMC3139583 DOI: 10.1371/journal.pone.0021928] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 06/09/2011] [Indexed: 11/22/2022] Open
Abstract
Local field-potentials (LFPs) are generated by neuronal ensembles and contain information about the activity of single neurons. Here, the LFPs of the cerebellar granular layer and their changes during long-term synaptic plasticity (LTP and LTD) were recorded in response to punctate facial stimulation in the rat in vivo. The LFP comprised a trigeminal (T) and a cortical (C) wave. T and C, which derived from independent granule cell clusters, co-varied during LTP and LTD. To extract information about the underlying cellular activities, the LFP was reconstructed using a repetitive convolution (ReConv) of the extracellular potential generated by a detailed multicompartmental model of the granule cell. The mossy fiber input patterns were determined using a Blind Source Separation (BSS) algorithm. The major component of the LFP was generated by the granule cell spike Na+ current, which caused a powerful sink in the axon initial segment with the source located in the soma and dendrites. Reproducing the LFP changes observed during LTP and LTD required modifications in both release probability and intrinsic excitability at the mossy fiber-granule cells relay. Synaptic plasticity and Golgi cell feed-forward inhibition proved critical for controlling the percentage of active granule cells, which was 11% in standard conditions but ranged from 3% during LTD to 21% during LTP and raised over 50% when inhibition was reduced. The emerging picture is that of independent (but neighboring) trigeminal and cortical channels, in which synaptic plasticity and feed-forward inhibition effectively regulate the number of discharging granule cells and emitted spikes generating “dense” activity clusters in the cerebellar granular layer.
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Affiliation(s)
- Shyam Diwakar
- Department of Physiology, University of Pavia, Pavia, Italy
- Consorzio Interuniversitario per le Scienze Fisiche della Materia (CNISM), Pavia, Italy
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham (Amrita University), Kollam, Kerala, India
| | - Paola Lombardo
- Department of Physiology, University of Pavia, Pavia, Italy
| | - Sergio Solinas
- Brain Connectivity Center, Fondazione Istituto Neurologico Nazionale IRCCS C. Mondino, Pavia, Italy
| | | | - Egidio D'Angelo
- Department of Physiology, University of Pavia, Pavia, Italy
- Brain Connectivity Center, Fondazione Istituto Neurologico Nazionale IRCCS C. Mondino, Pavia, Italy
- * E-mail:
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D'Angelo E, Mazzarello P, Prestori F, Mapelli J, Solinas S, Lombardo P, Cesana E, Gandolfi D, Congi L. The cerebellar network: from structure to function and dynamics. ACTA ACUST UNITED AC 2010; 66:5-15. [PMID: 20950649 DOI: 10.1016/j.brainresrev.2010.10.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 10/04/2010] [Accepted: 10/06/2010] [Indexed: 10/19/2022]
Abstract
Since the discoveries of Camillo Golgi and Ramón y Cajal, the precise cellular organization of the cerebellum has inspired major computational theories, which have then influenced the scientific thought not only on the cerebellar function but also on the brain as a whole. However, six major issues revealing a discrepancy between morphologically inspired hypothesis and function have emerged. (1) The cerebellar granular layer does not simply operate a simple combinatorial decorrelation of the inputs but performs more complex non-linear spatio-temporal transformations and is endowed with synaptic plasticity. (2) Transmission along the ascending axon and parallel fibers does not lead to beam formation but rather to vertical columns of activation. (3) The olivo-cerebellar loop could perform complex timing operations rather than error detection and teaching. (4) Purkinje cell firing dynamics are much more complex than for a linear integrator and include pacemaking, burst-pause discharges, and bistable states in response to mossy and climbing fiber synaptic inputs. (5) Long-term synaptic plasticity is far more complex than traditional parallel fiber LTD and involves also other cerebellar synapses. (6) Oscillation and resonance could set up coherent cycles of activity designing a functional geometry that goes far beyond pre-wired anatomical circuits. These observations clearly show that structure is not sufficient to explain function and that a precise knowledge on dynamics is critical to understand how the cerebellar circuit operates.
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Affiliation(s)
- E D'Angelo
- Department of Physiology, University of Pavia, I-27100 Pavia, Italy.
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Dover K, Solinas S, D'Angelo E, Goldfarb M. Long-term inactivation particle for voltage-gated sodium channels. J Physiol 2010; 588:3695-711. [PMID: 20679355 PMCID: PMC2998221 DOI: 10.1113/jphysiol.2010.192559] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 07/28/2010] [Indexed: 12/18/2022] Open
Abstract
Action potential generation is governed by the opening, inactivation, and recovery of voltage-gated sodium channels. A channel's voltage-sensing and pore-forming α subunit bears an intrinsic fast inactivation particle that mediates both onset of inactivation upon membrane depolarization and rapid recovery upon repolarization. We describe here a novel inactivation particle housed within an accessory channel subunit (A-type FHF protein) that mediates rapid-onset, long-term inactivation of several sodium channels. The channel-intrinsic and tethered FHF-derived particles, both situated at the cytoplasmic face of the plasma membrane, compete for induction of inactivation, causing channels to progressively accumulate into the long-term refractory state during multiple cycles of membrane depolarization. Intracellular injection of a short peptide corresponding to the FHF particle can reproduce channel long-term inactivation in a dose-dependent manner and can inhibit repetitive firing of cerebellar granule neurons. We discuss potential structural mechanisms of long-term inactivation and potential roles of A-type FHFs in the modulation of action potential generation and conduction.
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Affiliation(s)
- Katarzyna Dover
- Department of Physiology,University of Pavia and Brain Connectivity Center, IRCCS C. Mondino, Via Mondino 2, I-27100 Pavia, Italy
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Solinas S, Nieus T, Crotta F, Masoli S, D’Angelo E. Realistic circuit modeling: large-scale simulations of the cerebellar granular layer. BMC Neurosci 2010. [PMCID: PMC3090818 DOI: 10.1186/1471-2202-11-s1-p117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Solinas S, Nieus T, D'Angelo E. A realistic large-scale model of the cerebellum granular layer predicts circuit spatio-temporal filtering properties. Front Cell Neurosci 2010; 4:12. [PMID: 20508743 PMCID: PMC2876868 DOI: 10.3389/fncel.2010.00012] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2009] [Accepted: 03/18/2010] [Indexed: 11/21/2022] Open
Abstract
The way the cerebellar granular layer transforms incoming mossy fiber signals into new spike patterns to be related to Purkinje cells is not yet clear. Here, a realistic computational model of the granular layer was developed and used to address four main functional hypotheses: center-surround organization, time-windowing, high-pass filtering in responses to spike bursts and coherent oscillations in response to diffuse random activity. The model network was activated using patterns inspired by those recorded in vivo. Burst stimulation of a small mossy fiber bundle resulted in granule cell bursts delimited in time (time windowing) and space (center-surround) by network inhibition. This burst–burst transmission showed marked frequency-dependence configuring a high-pass filter with cut-off frequency around 100 Hz. The contrast between center and surround properties was regulated by the excitatory–inhibitory balance. The stronger excitation made the center more responsive to 10–50 Hz input frequencies and enhanced the granule cell output (with spikes occurring earlier and with higher frequency and number) compared to the surround. Finally, over a certain level of mossy fiber background activity, the circuit generated coherent oscillations in the theta-frequency band. All these processes were fine-tuned by NMDA and GABA-A receptor activation and neurotransmitter vesicle cycling in the cerebellar glomeruli. This model shows that available knowledge on cellular mechanisms is sufficient to unify the main functional hypotheses on the cerebellum granular layer and suggests that this network can behave as an adaptable spatio-temporal filter coordinated by theta-frequency oscillations.
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Affiliation(s)
- Sergio Solinas
- Department of Physiology, University of Pavia and Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia Pavia, Italy
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Solinas S, Pauli U, Kuhnert P, Peterhans E, Fries R. Assignment of the porcine tumour necrosis factor alpha and beta genes to the chromosome region 7p11-q11 by in situ hybridization. Anim Genet 2009; 23:267-71. [PMID: 1503261 DOI: 10.1111/j.1365-2052.1992.tb00140.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The loci of the porcine tumour necrosis factor genes, alpha (TNFA) and beta (TNFB), have been chromosomally assigned by radioactive in situ hybridization. The genomic probes for TNFA and TNFB yielded signals above 7p11-q11, a region that has been shown earlier to carry the porcine major histocompatibility locus (SLA). These mapping data along with preliminary molecular studies suggest a genomic organization of the SLA that is similar to that of human and murine major histocompatibility complexes.
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Affiliation(s)
- S Solinas
- Institut für Nutztierwissenschaften, Gruppe Züchtungsbiologie, Zürich, Switzerland
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D'Angelo E, Koekkoek SKE, Lombardo P, Solinas S, Ros E, Garrido J, Schonewille M, De Zeeuw CI. Timing in the cerebellum: oscillations and resonance in the granular layer. Neuroscience 2009; 162:805-15. [PMID: 19409229 DOI: 10.1016/j.neuroscience.2009.01.048] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 01/21/2009] [Accepted: 01/24/2009] [Indexed: 11/16/2022]
Abstract
The brain generates many rhythmic activities, and the olivo-cerebellar system is not an exception. In recent years, the cerebellum has revealed activities ranging from low frequency to very high-frequency oscillations. These rhythms depend on the brain functional state and are typical of certain circuit sections or specific neurons. Interestingly, the granular layer, which gates sensorimotor and cognitive signals to the cerebellar cortex, can also sustain low frequency (7-25 Hz) and perhaps higher-frequency oscillations. In this review we have considered (i) how these oscillations are generated in the granular layer network depending on intrinsic electroresponsiveness and circuit connections, (ii) how these oscillations are correlated with those in other cerebellar circuit sections, and (iii) how the oscillating cerebellum communicates with extracerebellar structures. It is suggested that the granular layer can generate oscillations that integrate well with those generated in the inferior olive, in deep-cerebellar nuclei and in Purkinje cells. These rhythms, in turn, might play a role in cognition and memory consolidation by interacting with the mechanisms of long-term synaptic plasticity.
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Affiliation(s)
- E D'Angelo
- Department of Physiology, University of Pavia, CNISM (Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia), Via Forlanini 6, I-27100, Pavia, Italy.
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Mariana G, Ciavarella N, Mazzucconi MG, Antoncecchi S, Solinas S, Ranieri P, Pettini P, Agrestini F, Mandelli F. Evaluation of the effectiveness of DDAVP in surgery and in bleeding episodes in haemophilia and von Willebrand's disease. A study on 43 patients. Clin Lab Haematol 2008; 6:229-38. [PMID: 6440729 DOI: 10.1111/j.1365-2257.1984.tb00548.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
1-deamino-8-D-arginine-vasopressin (DDAVP), was used in a wide spectrum of clinical situations employing two different dosages (0.3 and 0.4 microgram/kg b.w.) for the management of 43 patients with factor VIII deficiencies--mild and moderate haemophilia A and von Willebrand's disease (vWD). In most instances, the drug was given in association with antifibrinolytics. Twenty-five dental extractions were carried out with two different protocols: one based upon a single infusion and the other based upon three infusions. Bleeding occurred in three patients regardless of the protocol used. The vasopressin analogue promptly stopped bleeding in 12 'spontaneous' open bleeds (haematuria, epistaxis, menometrorrhagia, gum bleeding) and it appears to be also effective in closed bleeds. DDAVP was used to minimize blood loss during surgical interventions and to avoid haemorrhage in the postoperative period. Nine surgical procedures were carried out in six vWD patients and three haemophiliacs. Bleeding occurred late in the postoperative period on one occasion only. No difference was demonstrated between the two doses of the drug either in terms of clinical benefit or rise of factor VIII coagulant activity. The efficacy of DDAVP and the absence of side-effects make this vasopressin analogue worthy of consideration as a reliable alternative to factor VIII concentrates in a wide variety of clinical situations.
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Solinas S, Forti L, Cesana E, Mapelli J, De Schutter E, D'Angelo E. Fast-reset of pacemaking and theta-frequency resonance patterns in cerebellar golgi cells: simulations of their impact in vivo. Front Cell Neurosci 2007; 1:4. [PMID: 18946522 PMCID: PMC2525929 DOI: 10.3389/neuro.03.004.2007] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Accepted: 12/07/2007] [Indexed: 11/24/2022] Open
Abstract
The Golgi cells are inhibitory interneurons of the cerebellar granular layer, which respond to afferent stimulation in vivo with a burst-pause sequence interrupting their irregular background low-frequency firing (Vos et al., 1999a. Eur. J. Neurosci. 11, 2621–2634). However, Golgi cells in vitro are regular pacemakers (Forti et al., 2006. J. Physiol. 574, 711–729), raising the question how their ionic mechanisms could impact on responses during physiological activity. Using patch-clamp recordings in cerebellar slices we show that the pacemaker cycle can be suddenly reset by spikes, making the cell highly sensitive to input variations. Moreover, the neuron resonates around the pacemaker frequency, making it specifically sensitive to patterned stimulation in the theta-frequency band. Computational analysis based on a model developed to reproduce Golgi cell pacemaking (Solinas et al., 2008Front. Neurosci., 2:2) predicted that phase-reset required spike-triggered activation of SK channels and that resonance was sustained by a slow voltage-dependent potassium current and amplified by a persistent sodium current. Adding balanced synaptic noise to mimic the irregular discharge observed in vivo, we found that pacemaking converts into spontaneous irregular discharge, that phase-reset plays an important role in generating the burst-pause pattern evoked by sensory stimulation, and that repetitive stimulation at theta-frequency enhances the time-precision of spike coding in the burst. These results suggest that Golgi cell intrinsic properties exert a profound impact on time-dependent signal processing in the cerebellar granular layer.
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Affiliation(s)
- Sergio Solinas
- Department of Cellular and Molecular Physiological and Pharmacological Sciences, University of Pavia and CNISM Italy
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Solinas S, Forti L, Cesana E, Mapelli J, De Schutter E, D'Angelo E. Computational reconstruction of pacemaking and intrinsic electroresponsiveness in cerebellar Golgi cells. Front Cell Neurosci 2007; 1:2. [PMID: 18946520 PMCID: PMC2525930 DOI: 10.3389/neuro.03.002.2007] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Accepted: 12/07/2007] [Indexed: 11/17/2022] Open
Abstract
The Golgi cells have been recently shown to beat regularly in vitro (Forti et al., 2006. J. Physiol. 574, 711–729). Four main currents were shown to be involved, namely a persistent sodium current (INa-p), an h current (Ih), an SK-type calcium-dependent potassium current (IK-AHP), and a slow M-like potassium current (IK-slow). These ionic currents could take part, together with others, also to different aspects of neuronal excitability like responses to depolarizing and hyperpolarizing current injection. However, the ionic mechanisms and their interactions remained largely hypothetical. In this work, we have investigated the mechanisms of Golgi cell excitability by developing a computational model. The model predicts that pacemaking is sustained by subthreshold oscillations tightly coupled to spikes. INa-p and IK-slow emerged as the critical determinants of oscillations. Ih also played a role by setting the oscillatory mechanism into the appropriate membrane potential range. IK-AHP, though taking part to the oscillation, appeared primarily involved in regulating the ISI following spikes. The combination with other currents, in particular a resurgent sodium current (INa-r) and an A-current (IK-A), allowed a precise regulation of response frequency and delay. These results provide a coherent reconstruction of the ionic mechanisms determining Golgi cell intrinsic electroresponsiveness and suggests important implications for cerebellar signal processing, which will be fully developed in a companion paper (Solinas et al., 2008. Front. Neurosci. 2:4).
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Affiliation(s)
- Sergio Solinas
- Department of Cellular and Molecular Physiological and Pharmacological Sciences, University of Pavia and CNISM Italy
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Tosti ME, Solinas S, Prati D, Salvaneschi L, Manca M, Francesconi M, Ciuffreda M, Girelli G, Mele A. An estimate of the current risk of transmitting blood-borne infections through blood transfusion in Italy. Br J Haematol 2002; 117:215-9. [PMID: 11918558 DOI: 10.1046/j.1365-2141.2002.03334.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We conducted a retrospective cohort study to estimate the incidence of major blood-borne agents among Italian blood donors and calculated the risk of infection among blood recipients using the 'incidence/window period model'. The study was conducted among 46 180 blood donors enrolled in six blood centres between 1994 and 1999. During follow-up, seven new infections were confirmed: three donors seroconverted for anti-human immunodeficiency virus (HIV); two for anti-hepatitis C virus (HCV); and two showed hepatitis B surface antigen (HBsAg) reactivity; no cases of syphilis were observed. The incidence rates per 100 000 person/years were: 4.06 (95% CI: 0.82-11.85) for HIV; 2.41 (95% CI: 0.29-8.70) for HCV; and 2.70 (95% CI: 0.32-9.77) for HBsAg; the incidence for total hepatitis B virus (HBV) infection was 9.77 per 100 000 person/years (95% CI: 1.16-35.36). The estimated risk of an infectious blood unit not being detected was: 2.45 (95% CI: 0.13-12.33) per 1 million units for HIV; 4.35 (95% CI: 0.30-22.39) for HCV; and 15.78 (95% CI: 1.16-84.23) for HBV. Overall, an estimated 22.58 per 1 million units are infected. In Italy, the risk of transfusion-transmitted infections is low and is similar to that in other western countries. The introduction of new more sensitive screening tests could reduce the residual risk of transfusion-transmitted infection by 40-80%.
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Affiliation(s)
- M E Tosti
- Reparto di Epidemiologia Clinica, Istituto Superiore di Sanità, Servizio Trasfusionale e Immunoematologia, Università La Sapienza, Rome, Italy.
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37
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Celik I, Krack W, Zeiler T, Kretschmer V, Solinas S, Gajek H, Lorenz W. Plasma histamine levels during plasmapheresis: difficult interpretation of adverse reactions to plasma substitutes. Inflamm Res 2001; 50 Suppl 2:S65-7. [PMID: 11411607 DOI: 10.1007/pl00020784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- I Celik
- Institute of Theoretical Surgery, Philipps University, Marburg, Germany.
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38
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D'Amato A, Nigri G, Pronio A, Montesani C, Ferrazza G, Rusignolo A, Solinas S, Ribotta G. [The use of autotransfusion in general surgery]. Ann Ital Chir 2000; 71:643-7; discussion 647-8. [PMID: 11347315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Authors expose their experience with autotransfusion, made during several years in a general surgery university department. Discussion is made about ethic and economical aspect of the philosophy guiding the most general concept of blood sparing, and different methods of autotransfusion; attention is then focused on practical experience made during two years (1995-1997) when the program worked well. On the whole, in 94 patients, 172 blood units were collected plus 10 plasma units obtained by aferesis. No method-related complications are have been observed. Elements who corresponded to difficulties or obstacles to the fully application of the method have been critically analyzed. Authors propose finally guide-lines which want to be valid proposal to increase method use while respecting at the best ethics, economics, efficacy and efficiency that must guide our work.
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Affiliation(s)
- A D'Amato
- Clinica Chirurgica VI, Dipartimento di II Clinica Chirurgica, Università di Roma La Sapienza.
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D'Amato A, Ferrazza G, Solinas S, Pronio AM, Montesani C, Ribotta G. Use of autologous blood in general surgery. Hepatogastroenterology 2000; 47:1241-4. [PMID: 11100323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND/AIMS Autologous blood predonation is still not as widespread as it should be in general surgery practice, even if the method is well-known and has benefits established in international literature. Authors describe the impact of an autotransfusion program, in a general surgery university department, focusing on management and cost problems. METHODOLOGY A description of the efficacy of the program during a yearlong activity period is presented. An analysis has been made about the quantity of predonated blood/plasma units, the quantity actually transfused and use of homologous blood. The problems which occurred and the cost are discussed. RESULTS The most used autotransfusion method was preoperative predeposit of autologous blood. The analysis of results focused on some organizational problems that need to be avoided in order to show the methods maximum benefits. In a large number of cases (some 50%) predeposit was not made because of several managing/technical problems. In another large number of cases (38%) the quantity of units predonated did not fully supply the needs and several patients received homologous products. In another number of cases predonated blood units were not used at all (61/34%). CONCLUSIONS Predeposit, preoperative hemodilution and intraoperative recovery, are methods that should all be available in a general surgery department to manage in the best way the single patients blood/plasma needs, reducing post-transfusion complication. To optimize the program and minimize waste some guidelines must be established, with the aim of a rational and correct use of the procedure. Despite the value of the method, and the favor encountered by the patients, we must not forget that the use of autologous blood is not costless.
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Affiliation(s)
- A D'Amato
- Clinica Chirurgica VI, Università La Sapienza Rome, Italy.
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40
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Locasciulli A, Testa M, Valsecchi MG, Bacigalupo A, Solinas S, Tomas JF, Ljungman P, Alberti A. The role of hepatitis C and B virus infections as risk factors for severe liver complications following allogeneic BMT: a prospective study by the Infectious Disease Working Party of the European Blood and Marrow Transplantation Group. Transplantation 1999; 68:1486-91. [PMID: 10589944 DOI: 10.1097/00007890-199911270-00010] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Severe liver disease, including fulminant hepatic failure and venoocclusive disease can occur after bone marrow transplantation (BMT). The aim of our study was to assess risk factors for veno occlusive disease and severe liver disease occurring within 6 months from BMT. METHODS A total of 193 consecutive patients from 15 BMT Centers were prospectively enrolled between January and June 1995. Data on donors and recipients before and after transplant were collected and included age, gender, alanine aminotransferase (ALT), hepatitis B (HBV), and hepatitis C virus (HCV) markers, hematological disease, status and type of BMT, conditioning regimen and graft versus host disease prophylaxis. Statistical analysis included univariate descriptive and multivariate analysis based on logistic regression on major end-points. RESULTS Forty-three of 193 patients died during the study period, and liver disease was the main cause of death (13 of 43, 30%). Incidence of severe veno occlusive disease was 8%, fulminant hepatic failure 0.5% and 12% of cases had ALT >500 U/L (normal < or =42 U/L). A de novo HBV or HCV infection occurred in 3.2 and 7% of patients respectively. Predictive risk factors for life-threatening liver disease were: unrelated donors (relative risk=5.8, confidence interval=1.7-19.8) and abnormal BMT donor ALT (relative risk=6.3, confidence interval=1. 5- 25.5). CONCLUSIONS This study indicates that ongoing or previous infection with HBV or HCV in donor or recipient is not an absolute contraindication for BMT. However, abnormal ALT levels in BMT donors were a significant predictor of potentially lethal liver complications. The occurrence of de novo HBV or HCV infection did not correlate with severity of liver disease observed in the first 6 months posttransplant. These findings should be carefully evaluated before disregarding HBV or HCV positive siblings with normal transaminase levels in favor of unrelated donors.
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Affiliation(s)
- A Locasciulli
- Clinica Pediatrica Università di Milano, Ematologia Pediatrica, Ospedal San Gerardo, Monza (Milano), Itlay
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41
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Corrias A, Mountjoy G, Piccaluga G, Solinas S. An X-ray Absorption Spectroscopy Study of the Ni K Edge in NiO−SiO2 Nanocomposite Materials Prepared by the Sol−Gel Method. J Phys Chem B 1999. [DOI: 10.1021/jp9927911] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Corrias
- Dipartimento di Scienze Chimiche, Università di Cagliari, Cittadella Universitaria di Monserrato, Strada Provinciale per Sestu Km 0.70, 09042 Monserrato, Cagliari, Italy, and School of Physical Sciences, University of Kent, Canterbury, CT2 7NR, U.K
| | - G. Mountjoy
- Dipartimento di Scienze Chimiche, Università di Cagliari, Cittadella Universitaria di Monserrato, Strada Provinciale per Sestu Km 0.70, 09042 Monserrato, Cagliari, Italy, and School of Physical Sciences, University of Kent, Canterbury, CT2 7NR, U.K
| | - G. Piccaluga
- Dipartimento di Scienze Chimiche, Università di Cagliari, Cittadella Universitaria di Monserrato, Strada Provinciale per Sestu Km 0.70, 09042 Monserrato, Cagliari, Italy, and School of Physical Sciences, University of Kent, Canterbury, CT2 7NR, U.K
| | - S. Solinas
- Dipartimento di Scienze Chimiche, Università di Cagliari, Cittadella Universitaria di Monserrato, Strada Provinciale per Sestu Km 0.70, 09042 Monserrato, Cagliari, Italy, and School of Physical Sciences, University of Kent, Canterbury, CT2 7NR, U.K
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Devoti D, Affanni M, Ampollini A, D'Angelo G, Guasti D, Melissari M, Solinas S. An atypical case of osteoid osteoma. Chir Organi Mov 1997; 82:423-6. [PMID: 9618982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- D Devoti
- Divisione Ortopedica, Azienda Ospedaliera, Parma
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Popescu NC, Chen MC, Simpson S, Solinas S, DiPaolo JA. A Burkitt lymphoma cell line with integrated Epstein-Barr virus at a stable chromosome modification site. Virology 1993; 195:248-51. [PMID: 8391183 DOI: 10.1006/viro.1993.1367] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Fluorescence in situ hybridization (FISH), Southern, and slot blotting were used to detect Epstein-Barr virus (EBV) DNA and RNA sequences in a Burkitt's lymphoma (BL) cell line derived from a North American patient (NAB-2). FISH analysis after hybridization with a BamHI "V" region of EBV showed that NAB-2 cells have EBV genome integrated at a single site on the short arm of chromosome 2(p13). Single hybridization signals were detected at homologous sites on both chromatoids and nuclei. Furthermore, hybridization of intact nuclei without formamide denaturation and heat allowed the detection of single specific viral RNA transcripts visible as "tracks" or "traces." Southern blot analysis confirmed the integration of EBV genome into the host DNA. Quantification of slot blot hybridization revealed that NAB-2 cells have on average one copy of EBV per cell. Virus insertion into chromosomal DNA caused a stable modification site expressed as a distinctive achromatic region adjacent to the band 2p13. The chromatid lesion at the site of EBV integration involving a recombinogenic and fragile site may have contributed to the development of the NAB-2 BL.
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Affiliation(s)
- N C Popescu
- Laboratory of Biology, National Cancer Institute, Bethesda, Maryland 20892
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44
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Shamay A, Solinas S, Pursel VG, McKnight RA, Alexander L, Beattie C, Hennighausen L, Wall RJ. Production of the mouse whey acidic protein in transgenic pigs during lactation. J Anim Sci 1991; 69:4552-62. [PMID: 1721617 DOI: 10.2527/1991.69114552x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The mouse whey acidic protein (WAP) gene was introduced into the genome of pigs and its expression was analyzed in the mammary gland. Mouse WAP was detected in milk of lactating females from five lines at levels between .5 and 1.5 g/liter, thereby representing as much as 2% of the total milk proteins. The corresponding mRNA was expressed in mammary tissue at levels similar to those of pig beta-lactoglobulin and beta-casein. The pattern of WAP secretion in three pigs over a period of 6 wk was quantitatively similar to that of pig beta-lactoglobulin. From the eight transgenic pigs analyzed, three successfully completed one lactational period, but five pigs stopped lactating a few days after parturition. Our results show that it is possible to produce large quantities of a foreign protein in milk of pigs over a full lactational period. However, expression of WAP can compromise the mammary gland and render it nonfunctional.
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Affiliation(s)
- A Shamay
- Lab. of Biochem. and Metab., NIDDK, NIH, Bethesda, MD
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45
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Mazzucconi MG, Ferrari A, Solinas S, Vitale A, Chistolini A, Federici AB, Mandelli F. Studies of von Willebrand factor in essential thrombocythemia patients treated with alpha-2b recombinant interferon. Haemostasis 1991; 21:135-40. [PMID: 1773983 DOI: 10.1159/000216217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The crucial role of the von Willebrand Factor (vWF) and its interaction with platelets in myeloproliferative disorders (MPD) have emerged in recent years. Recently, many authors have reported the therapeutical efficacy of interferon (IFN) in MPD with thrombocytosis in decreasing platelet number. The purpose of our report is to study the modifications of vWF in a series of 20 patients affected by essential thrombocythemia (ET) or MPD with thrombocytosis, treated with alpha 2b recombinant IFN (alpha 2b-rIFN). Patients were studied before treatment and after complete or partial response: vWF-related properties, bleeding time (BT) and ristocetin-induced platelet aggregation (RIPA) were evaluated. Before treatment, we found prolonged BT in 5 patients (25%), abnormal RIPA in 8 (40%), reduced factor VIII coagulant activity (VIII:C) in 2 (10%), reduced vWF-related antigen (vWF:Ag) in 5 (25%) and low vWF:ristocetin cofactor (vWF:Ricof) in 5 (25%). Twelve subjects were evaluated after hematologic remission: in all patients, BT, VIII:C, vWF:Ag and vWF:Ricof were within normal range or upper normal limits. RIPA was abnormal in 7 subjects. Multimer patterns of vWF were performed in 3 patients before and after treatment: 2 of them showed loss of high-molecular-weight multimers that seemed to recover at remission. IFN seems to induce improvement of platelet number and their functions in MPD with thrombocytosis.
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Affiliation(s)
- M G Mazzucconi
- Department of Human Biopathology, University La Sapienza, Rome, Italy
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46
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Mariani G, Solinas S, Pasqualetti D, Ghirardini A, Verani P, Buttó S, Lopez M, Moretti T. Induction of immunotolerance in hemophilia for high titre inhibitor eradication: a long-term follow-up. Thromb Haemost 1989; 62:835-9. [PMID: 2512676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Three hemophiliacs with high titre inhibitor were treated with a medium-high FVIII dose schedule (100 IU/kg bw daily) with the aim of inducing the immunotolerance. These patients were followed-up extensively concerning their immunological status and HIV serology. In all of them the inhibitor disappeared and normal FVIII kinetics were obtained after 22, 15 and 29 months. After eradication of the inhibitor, no recurrence took place in any of the patients. All the patients were HIV Ab positive before the beginning of the treatment. In one of them CD4+ cells fell progressively 32 months after the treatment was started, a full-blown AIDS showed up, and the patient died 5 1/2 years after the beginning of the treatment. In the second and third patient the CD4+ cells varied widely but remained greater than 400/microliter during the whole immunotolerance treatment. The latter two patients are AIDS and ARC free so far, but patient No. 2 developed a mild-to-severe thrombocytopenia. Considering the high cost of the treatment and the possibility that such an intensive administration of FVIII concentrates might worsen the immunological status of patients, this therapeutic procedure should only be applied with caution.
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Affiliation(s)
- G Mariani
- Dipartimento di Biopatologia Umana, Università di Roma La Sapienza, Italy
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Ghirardini A, Mariani G, Iacopino G, Tirindelli MC, Solinas S, Moretti T. Concentrated DDAVP: further improvement in the management of mild factor VIII deficiencies. Thromb Haemost 1987; 58:896-8. [PMID: 3124287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This study was carried out to evaluate the pharmacological efficacy of a new concentrated 1 Deamino - (8-D-arginine)-vasopressin (DDAVP) preparation. Concentrated DDAVP (C-DDAVP), (40 micrograms/mL) was given subcutaneously (s.c.) in hemophilia and von Willebrand Disease (vWD), and the response was evaluated in terms of factor VIII/vWF (VIII/von Willebrand Factor) complex response. This response was also compared to that obtained using the currently available commercial preparation (4 micrograms/mL) given either s.c. or intravenously (i.v.). The maximal f. VIII response after s.c. C-DDAVP was reached one hour after the injection (means:3.5 times the resting values) with an average decline of 15% at two hours. The response to s.c. C-DDAVP in patients with hemophilia was slightly better than that obtained with the diluted brand, but the difference did not reach any statistical significance even when the schedules were compared in the same patients. In type I (platelet normal subtype) vWD, a higher response in terms of factor VIII:C increase in comparison with hemophiliacs was obtained. Both Ristocetin co-factor activity (RiCof) and bleeding time responded to this vasopressin analogue, when administered subcutaneously.
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Affiliation(s)
- A Ghirardini
- Department of Human Biopathology, Hematology, University of Roma, La Sapienza, Italy
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Mannucci PM, Lombardi R, Bader R, Vianello L, Federici AB, Solinas S, Mazzucconi MG, Mariani G. Heterogeneity of type I von Willebrand disease: evidence for a subgroup with an abnormal von Willebrand factor. Blood 1985; 66:796-802. [PMID: 3876122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Type I von Willebrand disease (vWD) is characterized by equally low plasma concentrations of von Willebrand factor antigen (vWF:Ag) and ristocetin cofactor (RiCof) and by the presence of all vWF multimers in sodium dodecyl sulfate (SDS)-agarose gel electrophoresis. For 17 patients (13 kindreds) diagnosed with these criteria, we have studied the platelet contents of vWF:Ag and RiCof and the changes of these in plasma after DDAVP infusion. Platelet vWF:Ag and RiCof were normal in four kindreds (called "platelet normal" subgroup); following 1-deamino-8-D-arginine vasopressin; plasma vWF:Ag, RiCof and the bleeding time (BT) became normal. In six kindreds, platelet vWF:Ag and RiCof were equally low (platelet low); after DDAVP, plasma vWF:Ag and RiCof remained low, and the BT was prolonged. In three additional kindreds, platelets contained normal concentrations of vWF:Ag, but RiCof was very low (platelet discordant); even though a complete set of multimers was found in plasma and platelets, there was a relatively small amount of large multimers. After DDAVP, plasma vWF:Ag became normal, but RiCof remained low and the BT was very prolonged. These findings demonstrated that there can be an abnormal vWF (RiCof less than vWF:Ag) even in type I vWD, coexisting with a complete set of vWF multimers (platelet discordant); that the abnormal vWF can be shown more clearly in platelets than in plasma or else in plasma after DDAVP infusion; and that DDAVP normalizes the BT only in those patients with normal platelet levels of both vWF:Ag and RiCof (platelet normal).
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Chistolini A, Mazzucconi MG, Motta M, Solinas S, Tirindelli MC, Mariani G. Evaluation of the clotting defect in a factor XII-deficient kindred. Ric Clin Lab 1985; 15:241-5. [PMID: 3853270 DOI: 10.1007/bf03029194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A family with factor XII severe congenital deficiency is described. Factor XII activity and factor XII antigen were both undetectable in the propositus plasma; levels of FXII:C and FXII:Ag were intermediate in heterozygotes. Plasma prekallikrein activity was low in the propositus, whereas normal levels of antigen could be found, suggesting a defect of kallikrein activation due to factor XII deficiency.
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Viganò S, Mannucci PM, Solinas S, Bottasso B, Mariani G. Decrease in protein C antigen and formation of an abnormal protein soon after starting oral anticoagulant therapy. Br J Haematol 1984; 57:213-20. [PMID: 6547348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Changes in protein C antigen (PC:Ag) have been compared with those in factor II, VII, IX and X antigens (II:Ag; VII:Ag; IX:Ag and X:Ag) in 10 patients starting on oral anticoagulant therapy with warfarin, monitored with thrombotest. Between days 0 and 3 of therapy, PC:Ag decreased at the same rate as VII:Ag, whilst IX:Ag, X:Ag and II:Ag decreased at progressively slower rates. On days 15 and 21, clotting proteins and PC:Ag did not differ significantly. Before and after warfarin, PC:Ag had the same mobility on crossed immunoelectrophoresis in Ca2+-free agarose gel; with Ca2+, a protein with faster anodal mobility appeared on day 1 and became maximal 5 d after warfarin was started. These findings indicate that the rate of PC decrease is closer to that of factor VII than those of factors IX, X and II, and that an abnormal PC with poor Ca2+-binding properties appears soon after treatment is started. The early decrease in the physiological inactivator (i.e. PC) might contribute to the poor antithrombotic efficacy of anticoagulant therapy during the first days.
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