Download or read book Physiological Properties of Low density Ganglion Cells in the Primate Retina written by Colleen Elizabeth Rhoades and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The retina provides the sole source of visual information to the brain, yet the signal from the retina is only partially understood. In primates, there are ~20 types of output cells of the retina, called retinal ganglion cells, with each type extracting specific information about the visual scene and projecting to distinct targets in the brain. The five numerically dominant retinal ganglion cell types have been extensively studied, but much less is known about the computations of the remaining ganglion cell types. To understand the visual function of the retina in health and in disease, it is necessary to understand how distinctive signals in the diverse retinal ganglion cell types emerge within retinal circuits, and how they collectively encode visual inputs. This thesis explores the physiological properties of the low-density ganglion cell types. In total, large-scale multi-electrode recordings revealed the responses of 12 retinal ganglion cell types, each with distinctive spatial, temporal, and chromatic properties. Focusing on the ON and OFF smooth monostratified cell types, strikingly irregular receptive field structure composed of spatially segregated hotspots were observed, quite different from the classical view of retinal receptive fields. Direct visual stimulation and computational inference demonstrate strong nonlinearities in the retinal circuit which contribute to receptive field hotspots. Surprisingly, visual stimulation of different hotspots produced subtly different extracellular spike waveforms in the same cell, consistent with a dendritic contribution to hotspot structure. These findings suggest a unique visual computation and spike generation mechanism in the signals carried by smooth monostratified cells to the brain.
Download or read book Webvision written by Helga Kolb and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neurophysiological Aspects of Color Vision in Primates written by E. Zrenner and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: "To explain all nature is too difficult a task for anyone man or even for anyone age. Tis much better to do a little with certainty, and leave the rest for others that come after you, than to explain all things ... " Sir Isaac Newton (1642-1727) This book describes and discusses some new aspects of col or vision in primates which have emerged from a series of experiments conducted over the past 8 years both on single ganglion cells in monkey retina and on the visually evoked cortical potential in man: corresponding psychophysical mechanisms of human perception will be considered as well. An attempt will be made to better understand the basic mechanisms of color vision using a more comprehensive approach which takes into account new mechanisms found in single cells and relates them to those found valid for the entire visual system. The processing of color signals was followed up from the retina to the visual cortex and to the percepq.tal centers, as far as the available techniques permitted.
Download or read book Parallel Processing in the Visual System written by Jonathan Stone and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the mid-sixties, John Robson and Christina Enroth-Cugell, without realizing what they were doing, set off a virtual revolution in the study of the visual system. They were trying to apply the methods of linear systems analysis (which were already being used to describe the optics of the eye and the psychophysical performance of the human visual system) to the properties of retinal ganglion cells in the cat. Their idea was to stimulate the retina with patterns of stripes and to look at the way that the signals from the center and the antagonistic surround of the respective field of each ganglion cell (first described by Stephen Kuffier) interact to generate the cell's responses. Many of the ganglion cells behaved themselves very nicely and John and Christina got into the habit (they now say) of calling them I (interesting) cells. However. to their annoyance, the majority of neurons they recorded had nasty, nonlinear properties that couldn't be predicted on the basis of simple summ4tion of light within the center and the surround. These uncoop erative ganglion cells, which Enroth-Cugell and Robson at first called D (dull) cells, produced transient bursts of impulses every time the distribution of light falling on the receptive field was changed, even if the total light flux was unaltered.
Download or read book Physiological Classification of Retinal Ganglion Cells in the Salamander Retina written by Fernando Ohlweiler Rozenblit and published by . This book was released on 2015 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: The retina is a complex neural network, responsible for breaking down the visual scene into its distinctive features such as local contrast, motion and color. The retinal ganglion cells form the output layer of this network, and a typical vertebrate retina may contain more than 10 different ganglion cell types. These cells can be separated based on their anatomical or physiological properties, and each type is expected to relay information about distinct visual features to specific areas in the brain. Separating these channels of information is crucial for understanding how the visual scene...
Download or read book Retinal Ganglion Cells written by Raymond Chi Shing Wong and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The retina is responsible for encoding different aspects of the visual world. Light enters the eyes and is converted by the photoreceptors into electrochemical signals. These signals are processed by the retinal network and proceed afferently to the brain via the axons of the retinal ganglion cells (RGCs). The RGCs outputs are in the form of action potentials (spikes), which encrypt the visual information in terms of spike shape, firing frequencies, and the firing patterns. When the photoreceptors are gone due to disease, vision is lost. The idea of a retinal prosthesis is to activate the surviving RGCs by electrical stimulation in order to recreate vision. In this thesis, I have studied the physiological properties of the RGCs, and reconstructed natural RGC spike trains by electrical stimulation. Chapter 1 introduces the anatomy of the retina and the retinal neurons. How the RGCs respond to light. Electrical stimulation is also discussed. A brief historical summary of the receptive field properties and cell physiology is also presented. Chapter 2 characterizes the intrinsic properties of 16 morphologically defined types of rat RGCs. The intrinsic properties include the biophysical properties due to morphology and dendritic stratification, in addition to physiological properties such as firing behaviours. These properties are also compared with the cat RGC intrinsic properties in order to investigate the variations between the morphologically similar RGCs of the two species. The results suggest that the RGCs among species, even with similar morphologies, do not have conservative intrinsic properties. Chapter 3 examines the details of the spiking properties of the different rat RGC types. Spikes are initiated at the axonal initial segment. A 'single' spike recorded at the soma consists of an axonal spike and a somatic spike. The existence of the two spikes can be recognized by two humps in the phase plot, and further revealed in the higher derivatives of the membrane potential. A principal component analysis shows that the parameters extracted from the phase plots are very useful for a model-independent rat RGC classification. Chapter 4 establishes the foundations for electrical stimulation of the retina. The question is to what extent optimum placement of the stimulating and reference electrodes might be affected by anatomical location. Here we placed the stimulating electrode above or below the retinal inner limiting membrane and found no statistical difference between the thresholds. In addition, reflective axonal spikes from the cut end are discussed. Chapter 5 combines the knowledge obtained in the previous chapters for the sole purpose of reproducing natural RGC outputs when using electrical stimulation. The light responses of the eye under saccadic movements were recorded and used to form the stimulus patterns. The reconstructions were performed on the brisk-transient (BT) and the brisk-sustained (BS) RGCs. Our results suggested that BT RGCs are more capable of following the stimulated stimulus patterns over a wide range of frequencies than the BS RGCs. Chapter 6 concludes the whole thesis.
Download or read book Primate Retina and Choroid written by Wolf Krebs and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents Introduction .......................................... . 1 The Primate Eye ...................................... . 2 Embryology of Retina and Choroid ....................... . 4 Microscopic Anatomy .................................. . 4 Retina ............................................ . 4 Choroid ........................................... . 8 Material and Methods .................................. . 10 Fine Structure of the Retina 14 RetinaI Pigment Epithelium ............................. . 16 Photoreceptor Cells ................................... . 30 Outer Plexiform Layer and Horizontal Cells .................. . 64 Bipolar, Radial Clial, and Amacrine Cells .................... . 76 Canglion Cells and InternaI Limiting Membrane ............... . 98 Spatial Density of RetinaI Cells .......................... . 112 Fine Structure of the Choroid ........................... . 116 Choroidocapillaris and Its Fiber System ..................... . 118 Arteries, Veins, and Lymphatic Spaces ...................... . 134 Choroidal Nerves .................................... . 142 Cells of Choroidal Connective Tissue ....................... . 148 References ........................................... . 153 Index ................................................ . 157 vii This volume describes the morphology of the primate re tina as seen with the electron microscope. As it is an atlas, the electron micrographs are its most In trad lietian important part. The text accompanies the figures, highlighting selected topics either to explain structures or to point out structure-function relation ships. A scholarly review of the whole spectrum of research on the re tina and choroid is not feasible in a single volume. Thus, whenever available, review artides or monographs, rather than original work, are cited for reference.
Download or read book Functional Imaging and Classification of Retinal Ganglion Cells in the Living Primate Eye written by Tyler Christian Godat and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The primate fovea is perhaps the most important location for vision in the retina, being specialized for high resolution spatial and chromatic vision, but it has been traditionally difficult to study in ex vivo electrophysiology and especially in vivo. The crucial visual properties conferred by the fovea are mediated by neurons called retinal ganglion cells, which exist in twenty or more distinct types that all tile the retina and are present from the far periphery up to the inner edge of the foveal slope. Microelectrode recordings of foveal retinal ganglion cells have been challenging due to their reduced size and the fragility of tissue survival in excised retina. Some of these difficulties in observing individual cells have been overcome in the in vivo retina by combining high resolution fluorescence adaptive optics ophthalmoscopy with calcium imaging to optically record functional responses in the living primate eye. The work in this thesis advances knowledge of functional properties of retinal ganglion cells at the primate fovea by studying their responses to various stimuli in the living primate (macaca fascicularis) eye. This includes measurements of retinal ganglion cells' chromatic tuning and cone weightings, made possible by silent substitution style uniform chromatic flicker stimuli, and measurements of cells' spatial transfer functions, made possible by monochromatic drifting gratings of various spatial frequencies. In particular, the most common type of retinal ganglion cell, the midget, is studied extensively to generate a broader understanding of the specialization and importance of the primate fovea. This work thus provides a closer look at the in situ spatial, chromatic, and temporal properties of these retinal ganglion cells than ever before possible. A novel stimulation delivery arm as part of a dual adaptive optics ophthalmoscope is also developed as part of this work to improve the resolution and breadth of stimuli used to interrogate the functional properties of retinal ganglion cells. These imaging and stimulation techniques provide a suite of tools for assessing and characterizing the functional properties of retinal ganglion cells in vivo which will inform the next generation of vision restoration strategies such as optogenetics and retinal prostheses."--Pages xi-xii.
Download or read book Morphological and Physiological Properties of Amacrine Cells Located in the Ganglion Cell Layer of the Ferret Retina written by Sally Wabba Aboelela and published by . This book was released on 2003 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Retinal Ganglion Cell Layer written by John M. Van Buren and published by . This book was released on 1963 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Primate Visual System written by Jon H. Kaas and published by CRC Press. This book was released on 2003-07-28 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last 20 years of research have been marked by exceptional progress in understanding the organization and functions of the primate visual system. This understanding has been based on the wide application of traditional and newly emerging methods for identifying the functionally significant subdivisions of the system, their interconnections, the
Download or read book Eye Retina and Visual System of the Mouse written by Leo M. Chalupa and published by MIT Press. This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive guide to current research captures the first wave of studies in the field, with fifty-nine chapters by leading scholars that demonstrate the usefulness of mouse models as a bridge between experimental and clinical research. The opening chapters introduce the mouse as a species and research model, discussing such topics as the mouse's evolutionary history and the mammalian visual system. Subsequent sections explore more specialized subjects, considering optics, psychophysics, and the visual behaviors of mice; the organization of the adult mouse eye and central visual system; the development of the mouse eye (including comparisons to human development); the development and plasticity of retinal projections and visuotopic maps; mouse models for human eye disease (including glaucoma and cataracts); and the application of advanced genomic technologies (including gene therapy and genetic knockouts) to the mouse visual system. Readers of this reference will see th.
Download or read book The Structure of the Retina written by Santiago Ramón y Cajal and published by . This book was released on 1972 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Primate Retina and Choroid written by Wolf Krebs and published by Springer. This book was released on 1991 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Organization of the Retina written by Leo M. Chalupa and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development and Organization of the Retina offers an invaluable survey of contemporary research issues and methods dealing with the retina and retinal projections. The book's 19 chapters report on investigations into two areas: research into the organization of the mature retina and work on developmental issues. A sampling of chapter topics includes -- embryonic patterning of cone subtypes in the mammalian retina -- synaptic transmission between retinal neurons -- scaling the retina, macro and micro -- retinal ganglion cell axonal transport, and more.
Download or read book High Resolution Imaging in Microscopy and Ophthalmology written by Josef F. Bille and published by Springer. This book was released on 2019-08-13 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book provides a comprehensive overview of the application of the newest laser and microscope/ophthalmoscope technology in the field of high resolution imaging in microscopy and ophthalmology. Starting by describing High-Resolution 3D Light Microscopy with STED and RESOLFT, the book goes on to cover retinal and anterior segment imaging and image-guided treatment and also discusses the development of adaptive optics in vision science and ophthalmology. Using an interdisciplinary approach, the reader will learn about the latest developments and most up to date technology in the field and how these translate to a medical setting. High Resolution Imaging in Microscopy and Ophthalmology – New Frontiers in Biomedical Optics has been written by leading experts in the field and offers insights on engineering, biology, and medicine, thus being a valuable addition for scientists, engineers, and clinicians with technical and medical interest who would like to understand the equipment, the applications and the medical/biological background. Lastly, this book is dedicated to the memory of Dr. Gerhard Zinser, co-founder of Heidelberg Engineering GmbH, a scientist, a husband, a brother, a colleague, and a friend.
Download or read book Ryan s Retina E Book written by Charles P. Wilkinson and published by Elsevier Health Sciences. This book was released on 2017-04-17 with total page 2893 pages. Available in PDF, EPUB and Kindle. Book excerpt: The undisputed gold standard text in the field, Ryan's Retina is your award-winning choice for the most current, authoritative information on new technologies, surgical approaches, scientific advances and diagnostic and therapeutic options for retinal diseases and disorders. Packed with timely updates throughout, new illustrations, and a dedicated team of editors who extend Dr. Ryan’s legacy in retina, this outstanding 6th Edition is a must-have reference for retinal specialists, ophthalmologists, and fellows in training. Offers the most comprehensive content available on retina, balancing the latest scientific research and clinical correlations, covering everything you need to know on retinal diagnosis, treatment, development, structure, function, and pathophysiology. Provides a truly global perspective from five highly esteemed section editors and more than 350 other world authorities from across Europe, Asia, Australasia, and the Americas. Bullets Includes new chapters on widefield imaging, intraoperative OCT imaging, medical management of diabetes mellitus and age-related macular degeneration, and senile retinoschisis. Includes more than 1,150 brand-new illustrations, scans, and photographs throughout. Covers the explosion of new imaging options across optical coherence tomography (OCT), fundus imaging, and autofluorescence imaging, including a greatly expanded OCT imaging chapter that features crucial information on OCT-Angiography (OCT-A). Presents new pharmacotherapy data and the latest approaches in anti-VEGF therapy for age-related macular degeneration, diabetic retinopathy, and venous occlusive disease. Features an expanded online video library highlighting the latest surgical techniques and new coverage of complications of vitreoretinal surgery. Contains thorough content updates in every area of retina, including advanced imaging technologies, gene therapy, inflammation and immune responses, white dot syndromes, epigenetic mechanisms, transplantation frontiers to improve retinal function, macular hole, myopic eye disease, ocular trauma, drug delivery to the posterior segment, advances in macular surgery, vitrectomy and complex retinal detachment, tumors, and retinal genetics and biology. Expert ConsultTM eBook version included with purchase. This enhanced eBook experience allows you to search all of the text, figures, Q&As, and references from the book on a variety of devices.
