Download or read book The Spatiotemporal Receptive Field Properties of Rat Retinal Ganglion Cells written by Walter Ferdinand Heine and published by . This book was released on 2011 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The function of the retina is to encode relevant features of the visual world in the form of neural spike trains. These are transmitted to higher visual centers in the brain by retinal ganglion cells (RGCs), which form the neural output of the retina. Little is known about the receptive field properties of these cells in the rat. In vivo recording techniques were used to record from RGC axons while visual stimuli were displayed on a cathode ray tube. Rats have a wide visual field and large receptive fields. In order to capture the majority of the visual field, the monitor was placed in close proximity to the eye of the animal. Visual stimulus patterns such as luminance gratings appear distorted at a close viewing distance. We therefore simulated a spherical screen with the eye at its center. Cells shared many properties with those of other species but also exhibited some notable differences. Some cells exhibited the characteristic linear and nonlinear spatial summation of cat X and Y cells and were therefore labeled as X and Y-like. More rarely encountered cell types included the suppressed by contrast and ON-OFF surround cells. In contrast to their counterparts in the cat, X and Y-like cells in the rat had similar receptive field sizes. In the temporal domain, X-like cells exhibited sustained response dynamics to square wave modulated spots. Y-like cells, on the other hand, displayed both sustained and transient response dynamics. Both cell types responded to full field stimuli by reducing their gain at low temporal frequencies and exhibiting a resonance at higher frequencies. These results question the commonly assigned roles of X-like cells in high acuity vision and Y-like cells in motion detection. Anatomical data on their morphological properties and projection pattern will provide additional insight into their possible functional roles. Photodynamic staining provides a means of targeting cells for electrophysiological recordings that display specific morphological and projection patterns. We found enhanced photodynamic staining in media supplemented with oxygen or hydrogen peroxide. This information will aid future experiments correlating the anatomical and electrophysiological properties of RGC types.

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 Maintained Discharge and Adaptation Properties of Rat Retinal Ganglion Cells written by Daniel Kenneth Freeman and published by . This book was released on 2009 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Visual information is relayed from the eye to the brain by retinal ganglion cells whose axons make up the optic nerve. An experimental system was developed to allow in vivo recordings of action potentials from rat retinal ganglion cell fibers in response to visual stimuli of interest. In the presence of a uniformly illuminated receptive field, ganglion cells fire an irregular pattern of action potentials referred to as the maintained discharge. We characterized the statistics of the maintained discharge using interval distributions and power spectral densities. While spike trains collected under ketaminexylazine anesthesia were generally stationary, spike trains under urethane anesthesia were unstable, producing slow, unpredictable, quasi-periodic fluctuations in firing rate. Under both anesthetic conditions, high frequency (28.9-41.4Hz) oscillations were present in the spike trains, as evidenced by multi-modal interspike interval distributions and a clear peak in the power spectral density. Oscillations were present in the dark, but at a slightly lower frequency, indicating that the oscillations were generated independent of light, but can be modulated by light level. An integrate-and-fire model with input current consisting of Gaussian noise plus a sinusoidal drive described the oscillations well. Next, the light adaptive properties of ganglion cells were studied. Ganglion cells are known to decrease their sensitivity in inverse proportion to the light input, but the contrast levels required to induce adaptation has been given little attention. This brings in to question the degree to which ganglion cells exhibit luminance adaptation as the eyes scan a typical natural scene. Using a probed-sinewave paradigm, we found that even low contrast (15%) stimuli can induce adaptation, yielding both increases and decreases of ganglion cell sensitivity relative to baseline. Ganglion cell firing rate does not appear to be the direct cause for the adaptation, as a given modulation depth can produce a large range of sensitivities. Adaptation is still seen when the frequency of the sinewave was increased from 0.25Hz to 1Hz, indicating the timescale of adaptation is in the range of

Download or read book Investigation of Cone and Rod mediated Receptive Field Properties of Cat X Retinal Ganglion Cells at Different Retinal Locations written by David Leigh Bohnsack and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Receptive Field Properties of Retinal Ganglion Cells in the Turtle P s e u d e m y s S c r i p t a E l e g a n s written by Jim E. Fulbrook and published by . This book was released on 1979 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Receptive Fields Sensitivity and Directional Selectivity of Frog Retinal Ganglion Cells and the Effects of Ethanol and Picrotoxin on These Properties written by Ann-Christine Bäckström and published by . This book was released on 1982 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Response of the Cat Retinal Ganglion Cell written by Lawrence Henry Pinto and published by . This book was released on 1970 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Functional Decomposition of Retinal Ganglion Cell Receptive Fields written by Sören Johannes Zapp and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The retina has the fascinating ability to extract various visual features from our surroundings. This feature detection is enabled by nonlinear operations in the retinal circuitry. The nonlinear processing is in part attributed to retinal ganglion cells and to their signal integration of the presynaptic circuitry. Of particular interest are nonlinear subunits in the receptive field of ganglion cells that are thought to correspond to the excitatory inputs of presynaptic bipolar cells. As the access to bipolar cells is experimentally limited, subunits are typically inferred computationally fr...

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 Circuitry Underlying Response Properties of Neurons in the Primary Visual Cortex Spatiotemporal Receptive Field of Synaptic Inputs written by Chenmei Jennie Chen and published by . This book was released on 2009 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Latencies of the Spatial Components of the Retinal Ganglion Cell Receptive Field written by Mary Lou Mallon and published by . This book was released on 1986 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Spatial Organisation of Receptive Fields in Mammalian Retinal Ganglion Cells written by Craig R. Vonhoff and published by . This book was released on 2012 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of the Visual System written by Retina Research Foundation (U.S.). Symposium and published by MIT Press. This book was released on 1991 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of the Visual System presents a selection of current studies that clearly illustrate principles of visual system development. These range from retinal development in fish and frogs to the effects of abnormal visual experience on the primary visual cortex of the cat. The book is unique in addressing four specific and fundamental aspects of development: cell lineage and cell fate, specificity and targeting of axons, specification of visual cortex, and correlates of the critical period. Encompassing technical advances in cellular and molecular biology and in video imaging and microscopy, contributions in each of these areas provide new information at the cellular and molecular levels to complement the now classic descriptions of visual development previously available at the level of neural systems.ContributorsKaren L. Allendoerfer, David M. Altshuler, Antonella Antonini, Seymour Benzer, Edward M. Callaway, Constance L. Cepko, Hollis T. Cline, Max S. Cynader, N. W. Daw, Scott E. Fraser, K. Fox, Eckhard Friauf, Anirvan Ghosh, R. W. Guillery, William A. Harris, Christine E. Holt, Lawrence C. Katz, Susan McConnell, Pamela A. Raymond, Thomas A. Reh, Carla J. Shatz, Michael P. Stryker, Claudia A. 0. Stuermer, Mriganka Sur, David L. Turner, T. N. Wiesel

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 Spatial Point Patterns written by Adrian Baddeley and published by CRC Press. This book was released on 2015-11-11 with total page 830 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern Statistical Methodology and Software for Analyzing Spatial Point PatternsSpatial Point Patterns: Methodology and Applications with R shows scientific researchers and applied statisticians from a wide range of fields how to analyze their spatial point pattern data. Making the techniques accessible to non-mathematicians, the authors draw on th