Physiology of Photoreceptor Organs

Physiology of Photoreceptor Organs PDF Author: Michelangelo G.F. Fuortes
Publisher: Springer Science & Business Media
ISBN: 3642653405
Category : Medical
Languages : en
Pages : 784

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Book Description
This volume is a collection of essays which attempts to summarize the recent progress in the field of photoreceptor and retinal physiology. Reflecting the way in which research is organized, each author reports on the studies performed with the techniques with which he is most familiar: morpholo gical, chemical or physiological. The first chapters describe the structure of visual cells and the histological architecture of the retina. Next comes a summary of the laws governing photochemical reactions and a report on the biochemistry of photopigments. Four articles cover the optical properties of invertebrate eyes and the electrophysiology and the interactions of their photoreceptors. These are followed by a discussion of the properties of vertebrate eyes, including chapters on optics, on the electrical responses of rods and cones and on the functional organization of the retina. The final chapter provides an extensive review of retinal biochemistry and metabolism. Even though the experimental approach differs, all studies are directed toward the solution of two basic problems: transduction in the photoreceptors and orga nization (often called "information processing") in the retina. The central problem of photoreceptor cells is to determine how light produces a response. We know that illumination evokes electrical changes and we have recently learned a great deal about the features of these changes. The evidence indicates however that elaborate processes must be interposed between the ab sorption of photons by the pigment and the production of electric currents through the membrane. These intermediary cvents remain to be unraveled.

Physiology of Photoreceptor Organs

Physiology of Photoreceptor Organs PDF Author: Michelangelo G.F. Fuortes
Publisher: Springer Science & Business Media
ISBN: 3642653405
Category : Medical
Languages : en
Pages : 784

Get Book Here

Book Description
This volume is a collection of essays which attempts to summarize the recent progress in the field of photoreceptor and retinal physiology. Reflecting the way in which research is organized, each author reports on the studies performed with the techniques with which he is most familiar: morpholo gical, chemical or physiological. The first chapters describe the structure of visual cells and the histological architecture of the retina. Next comes a summary of the laws governing photochemical reactions and a report on the biochemistry of photopigments. Four articles cover the optical properties of invertebrate eyes and the electrophysiology and the interactions of their photoreceptors. These are followed by a discussion of the properties of vertebrate eyes, including chapters on optics, on the electrical responses of rods and cones and on the functional organization of the retina. The final chapter provides an extensive review of retinal biochemistry and metabolism. Even though the experimental approach differs, all studies are directed toward the solution of two basic problems: transduction in the photoreceptors and orga nization (often called "information processing") in the retina. The central problem of photoreceptor cells is to determine how light produces a response. We know that illumination evokes electrical changes and we have recently learned a great deal about the features of these changes. The evidence indicates however that elaborate processes must be interposed between the ab sorption of photons by the pigment and the production of electric currents through the membrane. These intermediary cvents remain to be unraveled.

Physiology of Photoreceptor Organs

Physiology of Photoreceptor Organs PDF Author: Israel Abramov
Publisher: Springer
ISBN:
Category : Medical
Languages : en
Pages : 808

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Webvision

Webvision PDF Author: Helga Kolb
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Physiology of Photoreceptor Organs

Physiology of Photoreceptor Organs PDF Author: Michelangelo G. F. Fuortes
Publisher:
ISBN: 9783642653414
Category :
Languages : en
Pages : 820

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Anatomy and Physiology

Anatomy and Physiology PDF Author: J. Gordon Betts
Publisher:
ISBN: 9781947172807
Category :
Languages : en
Pages : 0

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Vertebrate Photoreceptors

Vertebrate Photoreceptors PDF Author: Takahisa Furukawa
Publisher: Springer
ISBN: 9784431563358
Category : Medical
Languages : en
Pages : 0

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Book Description
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.

Anatomy & Physiology

Anatomy & Physiology PDF Author: Lindsay Biga
Publisher:
ISBN: 9781955101158
Category :
Languages : en
Pages :

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Book Description
A version of the OpenStax text

Principles of Regenerative Medicine

Principles of Regenerative Medicine PDF Author: Anthony Atala
Publisher: Academic Press
ISBN: 0123814235
Category : Science
Languages : en
Pages : 1203

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Book Description
Virtually any disease that results from malfunctioning, damaged, or failing tissues may be potentially cured through regenerative medicine therapies, by either regenerating the damaged tissues in vivo, or by growing the tissues and organs in vitro and implanting them into the patient. Principles of Regenerative Medicine discusses the latest advances in technology and medicine for replacing tissues and organs damaged by disease and of developing therapies for previously untreatable conditions, such as diabetes, heart disease, liver disease, and renal failure. - Key for all researchers and instituions in Stem Cell Biology, Bioengineering, and Developmental Biology - The first of its kind to offer an advanced understanding of the latest technologies in regenerative medicine - New discoveries from leading researchers on restoration of diseased tissues and organs

Comparative Physiology and Evolution of Vision in Invertebrates

Comparative Physiology and Evolution of Vision in Invertebrates PDF Author: H. Autrum
Publisher: Springer Science & Business Media
ISBN: 3642669999
Category : Science
Languages : en
Pages : 762

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Book Description
In the comparative physiology of photoreception by the Protista and the invertebrates two aspects are emphasized: (1) the diversity of visual processes in these groups and (2) their bearing upon general mechanisms of photoreception. Invertebrates have evolved a far greater variety of adaptations than vertebrates modifications aiding survival in the remarkably different biotopes they occupy. The number of species in itself suggests this multiformity; each of them has peculiarities of its own, in morphology as well as in physiology and behavior. But these special adaptations are variations on a few great themes. Although the catalogue of invertebrate species is immense, the literature concerning them nearly rivals it in extent-even if one considers only that fraction dealing with visual physiology. Taxonomy proceeds by grouping the species, categorizing them in genera, families, orders, and progressively larger units. Similarly, comparative physiology aims at an analogous, more or less compre hensive, classification. This Part A of Volume VII/6, like Part B that follows it, emphasizes the broad questions that concern groups larger than the individual species; in some cases these questions have general applicability. The middle course between approaches that are too specialized and those that are too general is often elusive, but here we attempt to follow it. The vast number of special adaptations-probably, as we have said, as large as the number of species-is beyond the range even of a handbook.

Photoreceptor Optics

Photoreceptor Optics PDF Author: A.W. Snyder
Publisher: Springer Science & Business Media
ISBN: 3642809340
Category : Science
Languages : en
Pages : 523

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Book Description
The above consideration indicates that at present many of the experi mental facts on PS in animals can be quantitatively explained within the limits of the "universal" photoreceptor membrane concept. Of course, existence of preferential orientation of the absorbing dipoles in the tubuli of the rhabdomeres can not be totally rejected. We hope that the concept of the "universal" photoreceptor membrane may serve as the useful instrument when dealing with newly discovered properties of visual cells so that true mechanisms of electrical and optical coupling will be searched for instead of assumptions being made on additional properties of the photoreceptor membrane in every new animal under study. 5. Absorption Spectrum of the Universal Photoreceptor Membrane and Spectral Sensitivity of the Photoreceptor 5. 1 Preliminary Notes It seems nearly self-evident that the absorption spectrum of the pho toreceptor membrane coincides exactly with that of the visual pigment it contains. Hence, the membrane must exhibit three bands of absorp tion - the principal band with its peak within the limits of visible spectrum (or a-peak); the secondary band between 340 and 380 nm (S peak); and the third, protein band, in the ultraviolet (UV) at 280 nm (COLLINS et al. , 1952). The main peak of absorption is located within the range 433-575 nm for retinol-based pigments and between 438 and 620 nm for 3-dehydroretinol-based pigments, the position of Amax de pending on many ecological factors.