Invertebrate Photoreceptors


Book Description

Invertebrate Photoreceptors: A Comparative Analysis covers the structure and pigment chemistry of invertebrate photoreceptors. The book discusses the photobehavior and photoreceptor systems of invertebrate animals; the protozoan photoreceptor; and the compound eye. The text also describes the crustacean and mollusc eyes; the vertebrate retinal photoreceptors; and the invertebrate eye and its visual pigments. The book concludes with discussions on primitive photoreceptors; spectral sensitivity, pigments, and color vision; and polarized light analysis. Biologists and people involved in the study of invertebrate photobiology will find the text invaluable.




Comparative Physiology and Evolution of Vision in Invertebrates


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.




Invertebrate Vision


Book Description

Publisher description




Photoreception and Vision in Invertebrates


Book Description

I see a man's life is a tedious one. Cymbeline, Act III, Sc. 6. It is well known that the best way to learn a subject is to teach it! Along the same lines one might also say that a pleasant way of learning a subject and at the same time getting to know quite a few of the workers active in it, is to arrange and to attend an Advanced Study Institute (ASI) or a workshop lasting about two weeks. This was and is the wisdom behind the NA TO-ASI programme and much as people fear that a fortnight may be too long, before it is over everyone feels that it was too short, especially if the weather had cooperated. Organising this ASI which resulted in this volume has been a very good learning experience. I started my career in research with invertebrates and retained an interest in them over the years due to my teaching a course and working sporadically on various aspects of photoreception in Polychaetes, Crustaceans and Insects. Thus, the thought of organising an ASI on photoreception and vision in invertebrates had been brewing in my mind for the past half a dozen years or so. It was felt that it will be desirable to do a bit of stock taking and discuss possible new approaches to the study of this matter.




Comparative Physiology and Evolution of Vision in Invertebrates


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.




Photoreceptors


Book Description

The mechanism by which photoreceptor cells in the eyes of higher animals absorb light, giving rise to receptor potentials that initiate the visual process, is a subject of active research in biophysics today. The pace of this research and its multidisciplinary nature have made it difficult for the nonexpert to keep abreast of new discoveries. This book aims to provide a more coherent, compact summary of our knowledge about the field that has been available, serving as an up-to-date introduction to the role of photoreceptors in vision. The book is a self-contained, concise handbook for the reader who has at least a college level knowledge if cell biology, biochemistry, physical chemistry, neurobiology and physics. The authors describe the physical parameters of light and proceed to describe the mechanisms by which photoreceptors extract information about each parameter. The discussion of mechanisms is organized by discipline, following the general sequence of cellular morphology, visual pigment chemistery, and receptor physiology. Photoreceptors: their role in vision is an integrated sourcebook which will serve the novice as a 'stepping stone' to the vast and exciting scientific literature of the field.




Signal Transduction in Photoreceptor Cells


Book Description

This book deals with the mechanism of signal transduction in vertebrate and invertebrate photoreceptors. It contains contributions on the structure and function of rhodopsin or other G-coupled receptors, on the regulation of second messengers by enzyme cascade, the role of Ca2+ in light adaptation, control of ionic channels in photoreceptor cells.




Vertebrate Photoreceptors


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.




Biophysics Of Photoreception: Molecular And Phototransductive Events


Book Description

This is the first volume of new book series on biophysics and biocybernetics, initiated by the Istituto Italiano per gli Studi Filosofici.A main problem in biophysics is the interaction of light information with functional living structures, in order to shape the organism's behaviour. Although the processes of photoreception and phototransduction are articulated in various ways in different living beings — as it is seen in the subdivision of the topics in this volume on microorganisms, invertebrates, and vertebrates — general ways of light signal reception and transduction through light energy, i.e., photosensitive molecule interactions, could be observed. Highly sophisticated advanced techniques are employed in this research field.




Photoprocesses, Photoreceptors, and Evolution


Book Description

Photoprocesses, Photoreceptors, and Evolution discusses the important role that visible radiation has played in the development of photoreceptor systems, hence, in the evolution of life on earth. The book examines the spectrum of energies that impinge on the Earth, what kinds of molecules absorb these energies, and how they are structured within the cell to function as a photoreceptor system. The text describes the molecular structure of the cell membrane; the various kinds of pigment molecules; and the structures associated with photobiological phenomena. The relationship between the photoreceptor system and behavior, i.e. phototropism and phototaxis, photosynthesis, and vision, is also considered. The book further tackles the photoprocesses which function in photoperiodic phenomena - the "biological clocks, aging, memory, and bioluminescence. The text then demonstrates the structure of the invertebrate and vertebrate photoreceptors; and the intervebrate and vertebrate visual pigments and their photochemistry. Photobiologists will find the book invaluable.