Calcium regulation in photoreceptors
- 1 January 2002
- journal article
- review article
- Published by IMR Press in Frontiers in Bioscience-Landmark
- Vol. 7 (4), d2023-2044
- https://doi.org/10.2741/a896
Abstract
In this review we describe some of the remarkable and intricate mechanisms through which the calcium ion (Ca2+) contributes to detection, transduction and synaptic transfer of light stimuli in rod and cone photoreceptors. The function of Ca2+ is highly compartmentalized. In the outer segment, Ca2+ controls photoreceptor light adaptation by independently adjusting the gain of phototransduction at several stages in the transduction chain. In the inner segment and synaptic terminal, Ca2+ regulates cells' metabolism, glutamate release, cytoskeletal dynamics, gene expression and cell death. We discuss the mechanisms of Ca2+ entry, buffering, sequestration, release from internal stores and Ca2+ extrusion from both outer and inner segments, showing that these two compartments have little in common with respect to Ca2+ homeostasis. We also investigate the various roles played by Ca2+ as an integrator of intracellular signaling pathways, and emphasize the central role played by Ca2+ as a second messenger in neuromodulation of photoreceptor signaling by extracellular ligands such as dopamine, adenosine and somatostatin. Finally, we review the intimate link between dysfunction in photoreceptor Ca2+ homeostasis and pathologies leading to retinal dysfunction and blindness.Keywords
This publication has 100 references indexed in Scilit:
- Estimates for the pool size of releasable quanta at a single central synapse and for the time required to refill the pool.Proceedings of the National Academy of Sciences, 1995
- Modulation of ion channels in rod photoreceptors by nitric oxideNeuron, 1994
- Activation of bovine rod outer segment phosphatidylinositol-4,5-bisphosphate phospholipase C by calmodulin antagonists does not depend on calmodulinBiochemistry, 1991
- Localization of the inositol 1,4,5-trisphosphate receptor in synaptic terminals in the vertebrate retinaNeuron, 1991
- Ionic channels of the inner segment of tiger salamander cone photoreceptors.The Journal of general physiology, 1989
- Light induces a rapid and transient increase in inositol-trisphosphate in toad rod outer segmentsBiochemical and Biophysical Research Communications, 1987
- Dopaminergic Regulation of Cone Retinomotor Movement in Isolated Teleost Retinas: I. Induction of Cone Contraction Is Mediated by D2 ReceptorsJournal of Neurochemistry, 1986
- Light-mediated breakdown of phosphatidylinositol-4,5-bisphosphate in isolated rod outer segments of frog photoreceptorBiochemical and Biophysical Research Communications, 1985
- Phosphatidylinositol 4,5-bisphosphate: Light-mediated breakdown in the vertebrate retinaBiochemical and Biophysical Research Communications, 1984
- Smooth endoplasmic reticulum and other agranular reticulum in frog retinal photoreceptorsJournal of Neurocytology, 1982