G Protein Signaling Mechanisms in the Retina, 2014 Springer Series in Vision Research Series, Vol. 3

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.

1. Introduction: G-protein Signaling in the Retina.- Part One- Phototransduction in Rods and Cones.- 2. G-protein Deactivation Mechanisms in Vertebrate Phototransduction.- 3. Signaling by Rod and Cone Photoreceptors: Opsin Properties, G-protein Assembly and Mechanisms of Activation.- 4. G-protein–effector Coupling in the Vertebrate Phototransduction Cascade.- Part II- Inner Retinal GPCR Signaling Pathways.- 5. Interdependence among Members of the mGluR6 G-protein Mediated Signalplex of Retinal Depolarizing Bipolar Cells.- 6. Mechanistic Basis for G-protein Function in ON Bipolar Cells.- 7. Modulation of Trpm1 and the mGluR6 cascade in ON Bipolar Cells.- 8. The Role of Dopamine in Fine-tuning Cone- and Rod-driven Vision.- 9. Regulation of Electrical Synaptic Plasticity in the Retina by G-protein Coupled Receptors.- Part III- Signaling by Photosensitive Ganglion Cells.- 10. The Functional Properties of the G-protein-coupled Receptor melanopsin in Intrinsically Photosensitive Retinal Ganglion Cells.

Includes descriptions of all GPCR-mediated signaling pathways in the retina that contribute to visual and circadian function Brings together the most prominent experts in retinal biology, and it challenges them to generate a thoughtful discussion interconnected among the chapters Organized to allow readers, particularly those outside the field, to understand how light-evoked signals in the retina are generated Includes supplementary material: sn.pub/extras