Download or read book Formation of Space time Patterns at Ganglion Cell Layers in the Tiger Salamander Retina written by Erik Joseph Nemeth and published by . This book was released on 2000 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Formation of ON and OFF Ganglion Cell Mosaics in the Mammalian Retina written by Gayathri Jeyarasasingam and published by . This book was released on 1997 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Encoding Visual Features by Parallel Ganglion Cell Initiated Pathways in the Healthy Diseased and Artificial Retina written by Béla Völgyi and published by Frontiers Media SA. This book was released on 2019-10-16 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photons are sensed by retinal photoreceptors whose matrix-like distribution underlies the transformation of illumination patterns of the visual scene into photoreceptor activity patterns in a visuotopic fashion. Activity of neighboring photoreceptors then are compared by secondary bipolar cells to decipher information regarding luminosity- and color-contrast. Bipolar cells achieve this by comparing signals received directly from their center receptive field with those come from spatially offset surrounding receptive field areas mediated by inhibitory, sign-inverting horizontal cells. This information is ultimately sent to retinal ganglion cells, the output neurons of the retina. In addition to the excitatory bipolar cell inputs, spatial and temporal features of ganglion cell activation are robustly modified by inner retinal amacrine cells through inhibitory chemical and/or excitatory electrical synaptic inputs. Ganglion cells sample various bipolar cell subtypes in their dendritic field and utilize collected inputs to generate a spike output code on luminosity-contrast, color-contrast, object motion, background motion, motion direction, changes in background illumination in a subtype specific manner. Ganglion cells in each subtype cover the retinal surface economically, thus collective information across the population provide a feature pattern and through time a feature movie to the brain. Some of these movies are utilized for image perception, whereas others are sent to accessory visual brain centers to control eye-movement, pupil contraction or circadian entrainment. A large body of information has been revealed in the past decade regarding this field, however much of the details still remain unknown or even enigmatic, including: (i) the precise description of neural circuits that serve each ganglion cell subtype to generate a specific feature movie; (ii) the estimation of the number of various ganglion cell subtypes that partake in image forming and non-image forming signaling towards the brain; (iii) the description of changes in the inputs, morphology and signaling of retinal ganglion cells when the tissue is under stress or undergoes disease related degenerative processes; (iv) the comparison of ganglion cell classes with those of the human retina and finally, (v) the practical use of all the above information to establish retina inspired visual algorithms to suit computer, drone and/or robotic vision. Therefore, research articles in this issue were collected to touch upon each of these topics and highlight recent advances of the related field.
Download or read book A Functional Analysis of the Excitatory Synaptic Inputs to On off Ganglion Cells in the Aquatic Tiger Salamander Retina written by Birgit Werner and published by . This book was released on 2009 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The majority of ganglion cells in the salamander retina receive excitatory synaptic inputs from the ON and the OFF pathway, but little is known about the functional role of these cells. Previous studies suggest that they might be involved in the processing of complex visual features, however attempts to categorize cells into distinct groups of complex feature detectors have failed. This work focuses on the functional analysis of the excitatory synaptic inputs to ON-OFF ganglion cells recorded in the retinal slice preparation. Responses to stimulation with contrast steps and random luminance sequences were analyzed regarding their temporal dynamics and contrast processing. We found that cells lie along a continuum of varying relative contributions from the ON and the OFF pathway and show asymmetries regarding contrast processing and temporal dynamics in the OFF and ON inputs. We further investigated the use of a covariance based analysis to separate the ON and OFF components in current responses to white noise stimulation. Computer simulations were used to evaluate the performance of the analysis under different conditions. The analysis performs well in predicting the responses of simulated ON-OFF cells, however, caution needs to be applied in the physiological interpretation of the components of the estimated model, in particular if the assumption of contrast rectification is violated. Finally, we show how ON-OFF cells can account for complex temporal response patterns. We show how a simple ON-OFF model can produce spiking responses that seem to code for violations in periodic temporal patterns. The model is consistent with the results of patch clamp recordings of the excitatory current responses to periodic flash sequences. The model further demonstrates how relatively small changes in the static nonlinearities within the ON and the OFF pathway can produce a variety of seemingly complex response patterns in the spike output. In conclusion, ganglion cells in the salamander retina form a diverse group of cells varying along an ON-OFF continuum. The temporal asynchrony between the two pathways as well as variations in contrast rectification can account for complex response patterns observed in those cells and might play an important role in visual coding.
Download or read book Input Organization of Tiger Salamander Retinal Ganglion Cells written by Daniel Franklin Wunk and published by . This book was released on 1977 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Formation of ON and OFF Pathways in the Developing Rat Retina written by Emine Gunhan-Agar and published by . This book was released on 2001 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Vertical Interactions Among Parallel Image Representations in the Rabbit Retina written by Botond Miklos Roska and published by . This book was released on 2002 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Intrinsically Photosensitive Ganglion Cells of the Tiger Salamander Retina written by Kaveri Rajaraman and published by . This book was released on 2009 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parallel Processing in the Visual System written by Jonathan Stone and published by Springer. This book was released on 2012-03-17 with total page 454 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 Cumulated Index Medicus written by and published by . This book was released on 1976 with total page 1492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigative Ophthalmology Visual Science written by and published by . This book was released on 1991 with total page 1488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Society for Neuroscience Abstracts written by Society for Neuroscience (U.S.). Annual Meeting and published by . This book was released on 1999 with total page 1368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Visual Behavior in Salamanders written by Gerhard Roth and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: Salamanders are subject to misconceptions even among vertebrate zoologists and physiologists. They are often said to exist only in northern temperate zones, being bound to aquatic or very moist cool habitats. In reality, more than half of all salamander species live in subtropical and tropical zones, ex clusively in the New World. Again, more than half of the salamand~r species have become totally independent of aquatic habitats following the loss of a free larval stage. Many of the subtropical and tropical salamanders have become adapted to rather high temperatures up to 26-28 DC. The brain and the sensory systems of salamanders are often considered to be primitive, and their behavior is thought to be simple and uninfluenced by learning. However, careful studies show that the salamander brain possesses virtually all the ana tomical and functional properties found in anurans, which are usually regarded as being much more evolved with respect to the guidance of comparable behavior. Most of the salamander species not only possess a highly efficient visual system, which is the topic of the present work, but can orient themselves almost as effectively by means of olfaction, vibration sense, and electroreception. Furthermore, it has recently been shown that at least part of their behavior, especially that concerned with feeding and prey preferences, is strongly influenced by individual experience.
Download or read book Vertebrate Photoreceptors written by Takahisa Furukawa and published by Springer. This book was released on 2016-08-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a series of comprehensive views on various important aspects of vertebrate photoreceptors. The vertebrate retina is a tissue that provides unique experimental advantages to neuroscientists. Photoreceptor neurons are abundant in this tissue and they are readily identifiable and easily isolated. These features make them an outstanding model for studying neuronal mechanisms of signal transduction, adaptation, synaptic transmission, development, differentiation, diseases and regeneration. Thanks to recent advances in genetic analysis, it also is possible to link biochemical and physiological investigations to understand the molecular mechanisms of vertebrate photoreceptors within a functioning retina in a living animal. Photoreceptors are the most deeply studied sensory receptor cells, but readers will find that many important questions remain. We still do not know how photoreceptors, visual pigments and their signaling pathways evolved, how they were generated and how they are maintained. This book will make clear what is known and what is not known. The chapters are selected from fields of studies that have contributed to a broad understanding of the birth, development, structure, function and death of photoreceptor neurons. The underlying common word in all of the chapters that is used to describe these mechanisms is “molecule”. Only with this word can we understand how these highly specific neurons function and survive. It is challenging for even the foremost researchers to cover all aspects of the subject. Understanding photoreceptors from several different points of view that share a molecular perspective will provide readers with a useful interdisciplinary perspective.
Download or read book CSA Neurosciences Abstracts written by and published by . This book was released on 1984 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monthly, with annual subject and author indexes. Worldwide coverage of journal articles, papers presented, and books focused primarily on basic research in vertebrate and invertebrate neurosciences. Arranged under broad topics, e.g., genetics, sleep, and neurophysiology, as well as miscellaneous topics, book notices, and proceedings. Author, subject indexes.
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.
