G Protein Signaling Mechanisms in the Retina


Book Description

The main purpose of this volume is to provide a focused analysis of the function of the G protein-coupled signaling pathways that operate in the interconnected network of retinal neurons as they detect and encode the information carried by light. The organization of this volume will generally follow the path of signal flow in the retina. First we will describe recent advances in understanding the phototransduction cascade of rod and cone photoreceptors, which use signaling cascade based on the GPCR rhodopsin to transduce incident light into neural activity. Chapters will be devoted to unique specializations of the two major types of photosensitive cells that comprise the predominant input for our spatial and color vision. Subsequently, the mechanisms of synaptic information encoding by retinal ON bipolar cells will be described, where the GPCR mGluR6 plays a fundamental role. Chapters in this section will examine macromolecular organization of the mGluR6 signaling pathway as well as current understanding of its function. The functional characteristics of this signaling mechanism will be explored in detail. Additionally, this section will cover the role of dopamine receptors in modulating signal transmission between photoreceptors and ON-bipolar cells. Finally, chapters will be focused on the output neurons of the inner retina, ganglion cells, where the components of the emerging GPCR melanopsin cascade in intrinsically photosensitive ganglion cells will be detailed. Collectively these mechanisms allow the retina to represent visual space over a wide range of light intensities.




Webvision


Book Description




Signal Transduction in the Retina


Book Description

In the twenty-first century, we are just beginning to understand more clearly the enormous diversity and complexity of signaling processes in the retina. Integrating advances in the biochemistry, cell biology, physiology, and physics of phototransduction, Signal Transduction in the Retina presents the methodologies and experimental approache




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.




Adaptive Mechanisms in the Ecology of Vision


Book Description

John Lythgoe was one of the pioneers of the 'Ecology of Vision', a subject that he ably delineated in his classic and inspirational book published some 20 years ago [1]. At heart, the original book aimed generally to identify inter-relationships between vision, animal behaviour and the environment. John Lythgoe excelled at identifying the interesting 'questions' in the ecology of an animal that fitted the 'answers' presented by an analysis of the visual system. Over the last twenty years, however, since Lythgoe's landmark publication, much progress has been made and the field has broadened considerably. In particular, our understanding of the 'adaptive mechanisms' underlying the ecology of vision has reached considerable depths, extending to the molecular dimension, partly as a result of development and application of new techniques. This complements the advances made in parallel in clinically oriented vision research [2]. The current book endeavours to review the progress made in the ecology of vision field by bringing together many of the major researchers presently active in the expanded subject area. The contents deal with theoretical and physical considerations of light and photoreception, present examples of visual system structure and function, and delve into aspects of visual behaviour and communi cation. Throughout the book, we have tried to emphasise one of the major themes to emerge within the ecology of vision: the high degree of adaptability that visual mechanisms are capable of undergoing in response to diverse, and dynamic, environments and behaviours.




Drosophila Eye Development


Book Description

1 Kevin Moses It is now 25 years since the study of the development of the compound eye in Drosophila really began with a classic paper (Ready et al. 1976). In 1864, August Weismann published a monograph on the development of Diptera and included some beautiful drawings of the developing imaginal discs (Weismann 1864). One of these is the first description of the third instar eye disc in which Weismann drew a vertical line separating a posterior domain that included a regular pattern of clustered cells from an anterior domain without such a pattern. Weismann suggested that these clusters were the precursors of the adult ommatidia and that the line marks the anterior edge of the eye. In his first suggestion he was absolutely correct - in his second he was wrong. The vertical line shown was not the anterior edge of the eye, but the anterior edge of a moving wave of patterning and cell type specification that 112 years later (1976) Ready, Hansen and Benzer would name the "morphogenetic furrow". While it is too late to hear from August Weismann, it is a particular pleasure to be able to include a chapter in this Volume from the first author of that 1976 paper: Don Ready! These past 25 years have seen an astonishing explosion in the study of the fly eye (see Fig.




The Retina


Book Description




Photoreceptor Cell Biology and Inherited Retinal Degenerations


Book Description

This important book presents review articles on the cell biology of photoreceptor and RPE cells, as well as the relationship between this cell biology and inherited photoreceptor degeneration. The chapters have been written by leaders in the field. The vision scientist will see this book as a review of photoreceptor and RPE cell biology, and known molecular bases of many forms of retinitis pigmentosa and related retinal degeneration.




Photoreceptors and Calcium


Book Description

Text reviews the understanding of the role of calcium in phototransduction, dark-and light-adaptation, recovery from bleaching and return from the dark state, and synaptic signaling of photoreceptors and their second-order neurons. Includes color plates.