Biochemistry And Physiology Of Visual Pigments

This book is a report of a four-day Symposium on the Biochemistry and Physiology of Visual Pigments, which took place immediately after the VIth International Congress on Photobiology, held in Bochum, Federal Republic of Germany, in August 1972. This meeting, which brought together about 50 investigators of various aspects of the visual process, was devoted to the visual cells of both vertebrates and invertebrates. Whereas the International Symposium on the Biochemistry of the Retina, held at Nij megen, The Netherlands, in 1968, had concentrated on vertebrate photoreceptors, this Symposium dealt with invertebrate photoreceptors as well, so that workers in each field could become acquainted with recent progress in the other area. The papers presented at the Symposium were divided into six main topics, to each of which a half-day session was devoted. The six parts of this book, following the intro ductory lecture, essentially correspond to these sessions. In addition to the invited con tributions, the volume contains a number of short communications by other partici pants and two contributions by invited participants, who were unable to attend. The volume closes, as did the Symposium, with a General Discussion, prepared and moderated by S. L. BONTING, in which an attempt was made to integrate various new findings, and to reconcile certain points of disagreement.

Brings together key new results of interdisciplinary collaborations among various research fields on rhodopsin including the photoreceptive mechanism of rhodopsins, the molecular mechanism of the visual transduction process, visual processes in the retina and other transduction processes in the retina and brain. The structures of the rhodopsin molecule are studied in the fields of protein chemistry, molecular biology, organic chemistry and structural biology; the ultra fast reactions of the retinal protein are studied in physics, biophysics, physical chemistry, organic chemistry and photobiology; the phototransduction in retinal proteins and visual cells are studied in biophysics, biochemistry, biophysical chemistry and photobiology; and the localization in the tissues is studied in anatomy and histochemistry. The diversity of visual systems in various animals is studied in zoology and comparative biochemistry.

The aim of the 5th International Conference on Retinal Proteins was to present the findings of the interdisciplinary fields where photochemical, biophysical, molecular biology and physiological aspects are intimately linked. This title covers nearly all the presentations given during this symposium.

Biochemistry of Vision provides information pertinent to vision biochemistry. This book discusses the biochemical information derived primarily from studies on nonocular tissues and describes the biochemical reactions related to the function of the retina and pigmented epithelium. Organized into 16 chapters, this book begins with an overview of the visual system and the structure of the vertebrate eye. The text then proceeds with a discussion of photoreceptor, which has a highly membranous structure. Other chapters cover a brief discussion of several topics, including biomembranes, photochemistry, spectral properties of retinal isomers, and the photochemical properties of the chromophore of rhodopsin. This book discusses as well the properties and intramembrane disposition of rhodopsin. The final chapter deals with the biochemistry of photoreceptor disorders and summarizes the basic knowledge on neurotransmitters and electrophysiology in the retina. This book is intended for ophthalmologists and medical students who are interested in the molecular aspects of photoreceptor diseases.

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.

This book deals with the cellular biology, biochemistry and physiology of photoreceptors and their interactions with the second-order neurons, bipolar and horizontal cells. The focus is upon the contributions made by these neurons to vision. Thus the basic neurobiology of the outer retina is related to the visual process, and visual defects that could arise from abnormalities in this part of the retina are highlighted in the first 16 chapters. Since all vertebrate retinas have the same basic structure and physiological plan, examples are given from a variety of species, with an emphasis upon mammals, extending to human vision. The last four chapters approach the problem from the other end. This part of the book covers a range of clinical conditions involving visual abnormalities that are due to cellular defects in the outer retina. Although the contents of this book do not represent the proceedings of a conference, the concept arose at an international symposium on 'Recent Advances in Retinal Research' which was held at the International Marine Centre in Oristano, Sardinia. We hope that the book will give a coherent, up to date review of the neurobiology and clinical aspects of the outer retina and encourage further integration of these areas. Retinal neurobiology has been an intense field of investigation for several decades. More recently, it has seen significant advances with the application of modern techniques of cell and molecular biology.