Title

cGMP signaling in vertebrate retinal photoreceptor cells

Abstract

The visual transduction pathway in vertebrate photoreceptors transforms a light stimulus entering the photoreceptor outer segments into an electrical response at the synapses of rod and cone photoreceptor cells. This process is mediated by complex biochemical pathways that precisely regulate cGMP levels, thereby controlling the extent, duration, and adaptation of the photoreceptor to the light stimulus. This review first summarizes the major mechanisms of regulating cytoplasmic cGMP levels (synthesis, degradation, buffering, and efflux) as well as the primary targets of action of cGMP (cyclic nucleotide-gated ion channels, cGMP-dependent protein kinase, and cGMP-regulated phosphodiesterases). This information is applied to our current understanding of how these processes operate in the signal-transducing outer segment of rod and cone photoreceptors to carry out visual excitation, recovery, and adaptation in response to light stimulation.

Publication Date

5-1-2005

Journal Title

Frontiers in Bioscience

Publisher

Frontiers in Bioscience

Digital Object Identifier (DOI)

10.2741/1612

Scientific Contribution Number

2252

Document Type

Article

Rights

© Frontiers in Bioscience.