Glia–Neuron Interactions in Nervous System Function and Development
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Chapter 2 Test Review
Unit III, Modules 9-13 Test Review • See also the Unit III notes and pages 76-122 • About 45 m.c., plus two essays; one on brain functioning, the other review concepts from previous units. • Some practice questions are embedded in this presentation • Other practice questions are available at the textbook website and in the textbook after each module. Neuron Order of a transmission: dendrite, cell body, axon, synapse (see arrow below) Neural Communication Neurons, 80 Neural Communication • (a)Dendrite – the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the (b)cell body • (c)Axon – the extension of a neuron, ending in branching terminal fibers, through which messages are sent to other neurons or to muscles or glands • Myelin [MY-uh-lin] Sheath – a layer of fatty cells segmentally encasing the fibers of many neurons – makes possible vastly greater transmission speed of neutral impulses, – Damage to can lead to Multiple sclerosis Neural Communication • Action Potential – a neural impulse; a brief electrical charge that travels down an axon; DEPOLARIZED – generated by the movement of positively charges atoms in and out of channels in the axon’s membrane • Threshold – the level of stimulation required to trigger a neural impulse Action Potential A neural impulse. A brief electrical charge that travels down an axon and is generated by the movement of positively charged atoms in and out of channels in the axon’s membrane. Practice question • Multiple sclerosis is a disease that is most directly associated with the degeneration of: a. the myelin sheath. b. the pituitary gland. -
Crayfish Escape Behavior and Central Synapses
Crayfish Escape Behavior and Central Synapses. III. Electrical Junctions and Dendrite Spikes in Fast Flexor Motoneurons ROBERT S. ZUCKER Department of Biological Sciences and Program in the Neurological Sciences, Stanford University, Stanford, California 94305 THE LATERAL giant fiber is the decision fiber and fast flexor motoneurons are located in for a behavioral response in crayfish in- the dorsal neuropil of each abdominal gan- volving rapid tail flexion in response to glion. Dye injections and anatomical recon- abdominal tactile stimulation (27). Each structions of ‘identified motoneurons reveal lateral giant impulse is followed by a rapid that only those motoneurons which have tail flexion or tail flip, and when the giant dentritic branches in contact with a giant fiber does not fire in response to such stim- fiber are activated by that giant fiber (12, uli, the movement does not occur. 21). All of tl ie fast flexor motoneurons are The afferent limb of the reflex exciting excited by the ipsilateral giant; all but F4, the lateral giant has been described (28), F5 and F7 are also excited by the contra- and the habituation of the behavior has latkral giant (21 a). been explained in terms of the properties The excitation of these motoneurons, of this part of the neural circuit (29). seen as depolarizing potentials in their The properties of the neuromuscular somata, does not always reach threshold for junctions between the fast flexor motoneu- generating a spike which propagates out the rons and the phasic flexor muscles have also axon to the periphery (14). Indeed, only t,he been described (13). -
Signaling by Sensory Receptors
Signaling by Sensory Receptors David Julius1 and Jeremy Nathans2 1Department of Physiology, University of California School of Medicine, San Francisco, California 94158 2Department of Molecular Biology and Genetics, Johns Hopkins Medical School, Baltimore, Maryland 21205 Correspondence: [email protected] and [email protected] SUMMARY Sensory systems detect small molecules, mechanical perturbations, or radiation via the activa- tion of receptor proteins and downstream signaling cascades in specialized sensory cells. In vertebrates, the two principal categories of sensory receptors are ion channels, which mediate mechanosensation, thermosensation, and acid and salt taste; and G-protein-coupled recep- tors (GPCRs), which mediate vision, olfaction, and sweet, bitter, and umami tastes. GPCR- based signaling in rods and cones illustrates the fundamental principles of rapid activation and inactivation, signal amplification, and gain control. Channel-based sensory systems illus- trate the integration of diverse modulatory signals at the receptor, as seen in the thermosen- sory/pain system, and the rapid response kinetics that are possible with direct mechanical gating of a channel. Comparisons of sensory receptor gene sequences reveal numerous exam- ples in which gene duplication and sequence divergence have created novel sensory specific- ities. This is the evolutionary basis for the observed diversity in temperature- and ligand- dependent gating among thermosensory channels, spectral tuning among visual pigments, and odorant binding among olfactory receptors. The coding of complex external stimuli by a limited number of sensory receptor types has led to the evolution of modality-specific and species-specific patterns of retention or loss of sensory information, a filtering operation that selectively emphasizes features in the stimulus that enhance survival in a particular ecological niche. -
Long-Term Adult Human Brain Slice Cultures As a Model System to Study
TOOLS AND RESOURCES Long-term adult human brain slice cultures as a model system to study human CNS circuitry and disease Niklas Schwarz1, Betu¨ l Uysal1, Marc Welzer2,3, Jacqueline C Bahr1, Nikolas Layer1, Heidi Lo¨ ffler1, Kornelijus Stanaitis1, Harshad PA1, Yvonne G Weber1,4, Ulrike BS Hedrich1, Ju¨ rgen B Honegger4, Angelos Skodras2,3, Albert J Becker5, Thomas V Wuttke1,4†*, Henner Koch1†* 1Department of Neurology and Epileptology, Hertie-Institute for Clinical Brain Research, University of Tu¨ bingen, Tu¨ bingen, Germany; 2Department of Cellular Neurology, Hertie-Institute for Clinical Brain Research, University of Tu¨ bingen, Tu¨ bingen, Germany; 3German Center for Neurodegenerative Diseases (DZNE), Tu¨ bingen, Germany; 4Department of Neurosurgery, University of Tu¨ bingen, Tu¨ bingen, Germany; 5Department of Neuropathology, Section for Translational Epilepsy Research, University Bonn Medical Center, Bonn, Germany Abstract Most of our knowledge on human CNS circuitry and related disorders originates from model organisms. How well such data translate to the human CNS remains largely to be determined. Human brain slice cultures derived from neurosurgical resections may offer novel avenues to approach this translational gap. We now demonstrate robust preservation of the complex neuronal cytoarchitecture and electrophysiological properties of human pyramidal neurons *For correspondence: in long-term brain slice cultures. Further experiments delineate the optimal conditions for efficient [email protected] viral transduction of cultures, enabling ‘high throughput’ fluorescence-mediated 3D reconstruction tuebingen.de (TVW); of genetically targeted neurons at comparable quality to state-of-the-art biocytin fillings, and [email protected] demonstrate feasibility of long term live cell imaging of human cells in vitro. -
Beth Stevens: Casting Immune Cells As Brain Sculptors
Spectrum | Autism Research News https://www.spectrumnews.org PROFILES Beth Stevens: Casting immune cells as brain sculptors BY NICHOLETTE ZELIADT 24 SEPTEMBER 2015 Shortly after Beth Stevens launched her lab at Boston Children’s Hospital in 2008, she invited students from the Newton Montessori School, in a nearby suburb, to come for a visit. The children peered at mouse and rat brains bobbing in fluid-filled jars. They also learned how to position delicate slices of brain tissue on glass slides and inspect them with a microscope. This visit sparked a running relationship with the school, with a steady stream of students visiting the growing lab each year. Soon it became too complicated to bring so many children to the lab, so Stevens decided to take her neuroscience lessons on the road, visiting a number of local elementary schools each year. Last year, she dropped in on the classrooms of her 5- and 8-year- old daughters, Zoe and Riley. “The kids got really excited,” Stevens says. “It’s become such a thing that the principal wants me to come back for the whole school.” Stevens’ enthusiasm for science has left a lasting impression on researchers, too. Her pioneering work points to a surprise role in brain development for microglia, a type of cell once considered to simply be the brain’s immune defense system, cleaning up cellular debris, damaged tissue and pathogens. But thanks to Stevens, researchers now appreciate that these non-neuronal cells also play a critical role in shaping brain circuits. In a 2012 discovery that created a buzz among autism researchers, Stevens and her colleagues discovered that microglia prune neuronal connections, called synapses, in the developing mouse brain. -
Vocabulario De Morfoloxía, Anatomía E Citoloxía Veterinaria
Vocabulario de Morfoloxía, anatomía e citoloxía veterinaria (galego-español-inglés) Servizo de Normalización Lingüística Universidade de Santiago de Compostela COLECCIÓN VOCABULARIOS TEMÁTICOS N.º 4 SERVIZO DE NORMALIZACIÓN LINGÜÍSTICA Vocabulario de Morfoloxía, anatomía e citoloxía veterinaria (galego-español-inglés) 2008 UNIVERSIDADE DE SANTIAGO DE COMPOSTELA VOCABULARIO de morfoloxía, anatomía e citoloxía veterinaria : (galego-español- inglés) / coordinador Xusto A. Rodríguez Río, Servizo de Normalización Lingüística ; autores Matilde Lombardero Fernández ... [et al.]. – Santiago de Compostela : Universidade de Santiago de Compostela, Servizo de Publicacións e Intercambio Científico, 2008. – 369 p. ; 21 cm. – (Vocabularios temáticos ; 4). - D.L. C 2458-2008. – ISBN 978-84-9887-018-3 1.Medicina �������������������������������������������������������������������������veterinaria-Diccionarios�������������������������������������������������. 2.Galego (Lingua)-Glosarios, vocabularios, etc. políglotas. I.Lombardero Fernández, Matilde. II.Rodríguez Rio, Xusto A. coord. III. Universidade de Santiago de Compostela. Servizo de Normalización Lingüística, coord. IV.Universidade de Santiago de Compostela. Servizo de Publicacións e Intercambio Científico, ed. V.Serie. 591.4(038)=699=60=20 Coordinador Xusto A. Rodríguez Río (Área de Terminoloxía. Servizo de Normalización Lingüística. Universidade de Santiago de Compostela) Autoras/res Matilde Lombardero Fernández (doutora en Veterinaria e profesora do Departamento de Anatomía e Produción Animal. -
Oligodendrocytes in Development, Myelin Generation and Beyond
cells Review Oligodendrocytes in Development, Myelin Generation and Beyond Sarah Kuhn y, Laura Gritti y, Daniel Crooks and Yvonne Dombrowski * Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast BT9 7BL, UK; [email protected] (S.K.); [email protected] (L.G.); [email protected] (D.C.) * Correspondence: [email protected]; Tel.: +0044-28-9097-6127 These authors contributed equally. y Received: 15 October 2019; Accepted: 7 November 2019; Published: 12 November 2019 Abstract: Oligodendrocytes are the myelinating cells of the central nervous system (CNS) that are generated from oligodendrocyte progenitor cells (OPC). OPC are distributed throughout the CNS and represent a pool of migratory and proliferative adult progenitor cells that can differentiate into oligodendrocytes. The central function of oligodendrocytes is to generate myelin, which is an extended membrane from the cell that wraps tightly around axons. Due to this energy consuming process and the associated high metabolic turnover oligodendrocytes are vulnerable to cytotoxic and excitotoxic factors. Oligodendrocyte pathology is therefore evident in a range of disorders including multiple sclerosis, schizophrenia and Alzheimer’s disease. Deceased oligodendrocytes can be replenished from the adult OPC pool and lost myelin can be regenerated during remyelination, which can prevent axonal degeneration and can restore function. Cell population studies have recently identified novel immunomodulatory functions of oligodendrocytes, the implications of which, e.g., for diseases with primary oligodendrocyte pathology, are not yet clear. Here, we review the journey of oligodendrocytes from the embryonic stage to their role in homeostasis and their fate in disease. We will also discuss the most common models used to study oligodendrocytes and describe newly discovered functions of oligodendrocytes. -
Neuregulin 1–Erbb2 Signaling Is Required for the Establishment of Radial Glia and Their Transformation Into Astrocytes in Cerebral Cortex
Neuregulin 1–erbB2 signaling is required for the establishment of radial glia and their transformation into astrocytes in cerebral cortex Ralf S. Schmid*, Barbara McGrath*, Bridget E. Berechid†, Becky Boyles*, Mark Marchionni‡, Nenad Sˇ estan†, and Eva S. Anton*§ *University of North Carolina Neuroscience Center and Department of Cell and Molecular Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599; †Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510; and ‡CeNes Pharamceuticals, Inc., Norwood, MA 02062 Communicated by Pasko Rakic, Yale University School of Medicine, New Haven, CT, January 27, 2003 (received for review December 12, 2002) Radial glial cells and astrocytes function to support the construction mine whether NRG-1-mediated signaling is involved in radial and maintenance, respectively, of the cerebral cortex. However, the glial cell development and differentiation in the cerebral cortex. mechanisms that determine how radial glial cells are established, We show that NRG-1 signaling, involving erbB2, may act in maintained, and transformed into astrocytes in the cerebral cortex are concert with Notch signaling to exert a critical influence in the not well understood. Here, we show that neuregulin-1 (NRG-1) exerts establishment, maintenance, and appropriate transformation of a critical role in the establishment of radial glial cells. Radial glial cell radial glial cells in cerebral cortex. generation is significantly impaired in NRG mutants, and this defect can be rescued by exogenous NRG-1. Down-regulation of expression Materials and Methods and activity of erbB2, a member of the NRG-1 receptor complex, leads Clonal Analysis to Study NRG’s Role in the Initial Establishment of to the transformation of radial glial cells into astrocytes. -
Build a Neuron
Build a Neuron Objectives: 1. To understand what a neuron is and what it does 2. To understand the anatomy of a neuron in relation to function This activity is great for ALL ages-even college students!! Materials: pipe cleaners (2 full size, 1 cut into 3 for each student) pony beads (6/student Introduction: Little kids: ask them where their brain is (I point to my head and torso areas till they shake their head yes) Talk about legos being the building blocks for a tower and relate that to neurons being the building blocks for your brain and that neurons send messages to other parts of your brain and to and from all your body parts. Give examples: touch from body to brain, movement from brain to body. Neurons are the building blocks of the brain that send and receive messages. Neurons come in all different shapes. Experiment: 1. First build soma by twisting a pipe cleaner into a circle 2. Then put a 2nd pipe cleaner through the circle and bend it over and twist the two strands together to make it look like a lollipop (axon) 3. take 3 shorter pipe cleaners attach to cell body to make dendrites 4. add 6 beads on the axon making sure there is space between beads for the electricity to “jump” between them to send the signal super fast. (myelin sheath) 5. Twist the end of the axon to make it look like 2 feet for the axon terminal. 6. Make a brain by having all of the neurons “talk” to each other (have each student hold their neuron because they’ll just throw them on a table for you to do it.) messages come in through the dendrites and if its a strong enough electrical change, then the cell body sends the Build a Neuron message down it’s axon where a neurotransmitter is released. -
Primary Processes in Sensory Cells: Current Advances
J Comp Physiol A (2009) 195:1–19 DOI 10.1007/s00359-008-0389-0 REVIEW Primary processes in sensory cells: current advances Stephan Frings Received: 14 September 2008 / Revised: 25 October 2008 / Accepted: 25 October 2008 / Published online: 15 November 2008 © The Author(s) 2008. This article is published with open access at Springerlink.com Abstract In the course of evolution, the strong and unre- INAD Inactivation no after-potential D mitting selective pressure on sensory performance has MEC Mechanosensitive channel-related protein driven the acuity of sensory organs to its physical limits. As OHC Outer hair cell a consequence, the study of primary sensory processes ORN Olfactory receptor neuron illustrates impressively how far a physiological function PDE Phosphodiesterase can be improved if the survival of a species depends on it. PDZ Domain postsynaptic density/discs-large/zonula Sensory cells that detect single-photons, single molecules, occludens domain mechanical motions on a nanometer scale, or incredibly TRP Channel transient receptor potential channel small Xuctuations of electromagnetic Welds have fascinated VNO Vomeronasal organ physiologists for a long time. It is a great challenge to understand the primary sensory processes on a molecular level. This review points out some important recent develop- Introduction ments in the search for primary processes in sensory cells that mediate touch perception, hearing, vision, taste, olfac- Sensory cells provide the central nervous system with vital tion, as well as the analysis of light polarization and the ori- information about the body and its environment. Each sen- entation in the Earth’s magnetic Weld. The data are screened sory cell detects speciWc stimuli using highly specialized for common transduction strategies and common transduc- structures which operate as sensors for adequate stimuli. -
The Interplay Between Neurons and Glia in Synapse Development And
Available online at www.sciencedirect.com ScienceDirect The interplay between neurons and glia in synapse development and plasticity Jeff A Stogsdill and Cagla Eroglu In the brain, the formation of complex neuronal networks and regulate distinct aspects of synaptic development and amenable to experience-dependent remodeling is complicated circuit connectivity. by the diversity of neurons and synapse types. The establishment of a functional brain depends not only on The intricate communication between neurons and glia neurons, but also non-neuronal glial cells. Glia are in and their cooperative roles in synapse formation are now continuous bi-directional communication with neurons to direct coming to light due in large part to advances in genetic the formation and refinement of synaptic connectivity. This and imaging tools. This article will examine the progress article reviews important findings, which uncovered cellular made in our understanding of the role of mammalian and molecular aspects of the neuron–glia cross-talk that perisynaptic glia (astrocytes and microglia) in synapse govern the formation and remodeling of synapses and circuits. development, maturation, and plasticity since the previ- In vivo evidence demonstrating the critical interplay between ous Current Opinion article [1]. An integration of past and neurons and glia will be the major focus. Additional attention new findings of glial control of synapse development and will be given to how aberrant communication between neurons plasticity is tabulated in Box 1. and glia may contribute to neural pathologies. Address Glia control the formation of synaptic circuits Department of Cell Biology, Duke University Medical Center, Durham, In the CNS, glial cells are in tight association with NC 27710, USA synapses in all brain regions [2]. -
October 2004
Myelin Repair Foundation Research Progress Summary October 2004 This summary outlines progress made by the Myelin Repair Foundation research team since June 2004 and includes findings from on-going research funded by other sources that members of the team found relevant to MRF research plan. Since the success of MRF is dependent on collaboration, rather than reporting on the progress of individual projects, this report describes progress towards MRF’s overall research goals and the contributions of various team members towards completing our understanding of critical aspects of myelination and how it is affected by the multiple sclerosis (MS) disease process. 1. Fundamental control of myelination: There are several MRF investigations focused on understanding the processes that control both myelination in development and remyelination after myelin loss due to inflammation and cell death: • Dr. Ben Barres’ lab has screened thousands of genes and identified 46 genes, specific to the myelination process, that show significantly higher or lower activity levels during developmental myelination than before or after the myelination process. In addition, Dr. Barres’ lab has demonstrated the timing of these changes during the developmental myelination process. The next step is to analyze the function of each of these 46 genes by artificially controlling its level of activity (expression) and observing the effect it has on myelin formation. Finding ways to artificially manipulate the expression of each gene is a formidable task. Although the functional analysis of each gene in this group is a significant project that may take several years to complete because of the large number of genes to be analyzed, the initial identification of these active genes is providing clues to other MRF researchers that will help prioritize which genes to evaluate first and which to ignore.