Calcium Feedback to cGMP Synthesis Strongly Attenuates Single-Photon Responses Driven by Long Rhodopsin Lifetimes

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Rod photoreceptors generate amplified, reproducible responses to single photons via a G protein signaling cascade. Surprisingly, genetic perturbations that dramatically alter the deactivation of the principal signal amplifier, the GPCR rhodopsin (R&z.ast;), do not much alter the amplitude of single-photon responses (SPRs). These same perturbations, when crossed into a line lacking calcium feedback regulation of cGMP synthesis, produced much larger alterations in SPR amplitudes. Analysis of SPRs from rods with and without feedback reveal that the consequences of trial-to-trial fluctuations in R&z.ast; lifetime in normal rods are also dampened by feedback regulation of cGMP synthesis. Thus, calcium feedback trumps the mechanisms of R&z.ast; deactivation in determining the SPR amplitude, attenuating responses arising from longer R&z.ast; lifetimes to a greater extent than those arising from shorter ones. As a result, rod SPRs achieve a more stereotyped amplitude, a characteristic considered important for reliable transmission through the visual system.

Original languageEnglish (US)
Pages (from-to)370-382
Number of pages13
JournalNeuron
Volume76
Issue number2
DOIs
StatePublished - Oct 18 2012

Fingerprint

Rhodopsin
Photons
Calcium
Retinal Rod Photoreceptor Cells
GTP-Binding Proteins

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Calcium Feedback to cGMP Synthesis Strongly Attenuates Single-Photon Responses Driven by Long Rhodopsin Lifetimes. / Gross, Owen P.; Pugh Jr, Edward N; Burns, Marie E.

In: Neuron, Vol. 76, No. 2, 18.10.2012, p. 370-382.

Research output: Contribution to journalArticle

@article{33b7b7ec0f484935ab9e6a46121aef50,
title = "Calcium Feedback to cGMP Synthesis Strongly Attenuates Single-Photon Responses Driven by Long Rhodopsin Lifetimes",
abstract = "Rod photoreceptors generate amplified, reproducible responses to single photons via a G protein signaling cascade. Surprisingly, genetic perturbations that dramatically alter the deactivation of the principal signal amplifier, the GPCR rhodopsin (R&z.ast;), do not much alter the amplitude of single-photon responses (SPRs). These same perturbations, when crossed into a line lacking calcium feedback regulation of cGMP synthesis, produced much larger alterations in SPR amplitudes. Analysis of SPRs from rods with and without feedback reveal that the consequences of trial-to-trial fluctuations in R&z.ast; lifetime in normal rods are also dampened by feedback regulation of cGMP synthesis. Thus, calcium feedback trumps the mechanisms of R&z.ast; deactivation in determining the SPR amplitude, attenuating responses arising from longer R&z.ast; lifetimes to a greater extent than those arising from shorter ones. As a result, rod SPRs achieve a more stereotyped amplitude, a characteristic considered important for reliable transmission through the visual system.",
author = "Gross, {Owen P.} and {Pugh Jr}, {Edward N} and Burns, {Marie E}",
year = "2012",
month = "10",
day = "18",
doi = "10.1016/j.neuron.2012.07.029",
language = "English (US)",
volume = "76",
pages = "370--382",
journal = "Neuron",
issn = "0896-6273",
publisher = "Cell Press",
number = "2",

}

TY - JOUR

T1 - Calcium Feedback to cGMP Synthesis Strongly Attenuates Single-Photon Responses Driven by Long Rhodopsin Lifetimes

AU - Gross, Owen P.

AU - Pugh Jr, Edward N

AU - Burns, Marie E

PY - 2012/10/18

Y1 - 2012/10/18

N2 - Rod photoreceptors generate amplified, reproducible responses to single photons via a G protein signaling cascade. Surprisingly, genetic perturbations that dramatically alter the deactivation of the principal signal amplifier, the GPCR rhodopsin (R&z.ast;), do not much alter the amplitude of single-photon responses (SPRs). These same perturbations, when crossed into a line lacking calcium feedback regulation of cGMP synthesis, produced much larger alterations in SPR amplitudes. Analysis of SPRs from rods with and without feedback reveal that the consequences of trial-to-trial fluctuations in R&z.ast; lifetime in normal rods are also dampened by feedback regulation of cGMP synthesis. Thus, calcium feedback trumps the mechanisms of R&z.ast; deactivation in determining the SPR amplitude, attenuating responses arising from longer R&z.ast; lifetimes to a greater extent than those arising from shorter ones. As a result, rod SPRs achieve a more stereotyped amplitude, a characteristic considered important for reliable transmission through the visual system.

AB - Rod photoreceptors generate amplified, reproducible responses to single photons via a G protein signaling cascade. Surprisingly, genetic perturbations that dramatically alter the deactivation of the principal signal amplifier, the GPCR rhodopsin (R&z.ast;), do not much alter the amplitude of single-photon responses (SPRs). These same perturbations, when crossed into a line lacking calcium feedback regulation of cGMP synthesis, produced much larger alterations in SPR amplitudes. Analysis of SPRs from rods with and without feedback reveal that the consequences of trial-to-trial fluctuations in R&z.ast; lifetime in normal rods are also dampened by feedback regulation of cGMP synthesis. Thus, calcium feedback trumps the mechanisms of R&z.ast; deactivation in determining the SPR amplitude, attenuating responses arising from longer R&z.ast; lifetimes to a greater extent than those arising from shorter ones. As a result, rod SPRs achieve a more stereotyped amplitude, a characteristic considered important for reliable transmission through the visual system.

UR - http://www.scopus.com/inward/record.url?scp=84867725368&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84867725368&partnerID=8YFLogxK

U2 - 10.1016/j.neuron.2012.07.029

DO - 10.1016/j.neuron.2012.07.029

M3 - Article

VL - 76

SP - 370

EP - 382

JO - Neuron

JF - Neuron

SN - 0896-6273

IS - 2

ER -