The Journal of General Physiology
CrossRef
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 109K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JGP
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Matthews, H.R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Matthews, H.R.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?
© The Rockefeller University Press, 0022-1295/1997//141/ $5.00
Journal of General Physiology, Volume 109, Number 2, 1997

Article

Actions of Ca2+ on an Early Stage in Phototransduction Revealed by the Dynamic Fall in Ca2+ Concentration during the Bright Flash Response

H.R. Matthews

From the Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, United Kingdom

To study the actions of Ca2+ on "early" stages of the transduction cascade, changes in cytoplasmic calcium concentration (Ca2+i) were opposed by manipulating Ca2+ fluxes across the rod outer segment membrane immediately following a bright flash. If the outer segment was exposed to 0 Ca2+/0 Na+ solution for a brief period immediately after the flash, then the period of response saturation was prolonged in comparison with that in Ringer solution. But if the exposure to 0 Ca2+/0 Na+ solution instead came before or was delayed until 1 s after the flash then it had little effect. The degree of response prolongation increased with the duration of the exposure to 0 Ca2+/0 Na+ solution, revealing a time constant of 0.49 ± 0.03 s. By the time the response begins to recover from saturation, Ca2+i seems likely to have fallen to a similar level in each case. Therefore the prolongation of the response when Ca2+i was prevented from changing immediately after the flash seems likely to reflect the abolition of actions of the usual dynamic fall in Ca2+i on an early stage in the transduction cascade at a site which is available for only a brief period after the flash. One possibility is that the observed time constant corresponds to the phosphorylation of photoisomerized rhodopsin.

Key Words: photoreceptor • retinal rod • light adaptation • calcium • rhodopsin

Address correspondence to Dr. H.R. Matthews, Physiological Laboratory, University of Cambridge, Downing Street, Cambridge CB2 3EG, United Kingdom. Fax: 01223-333840; E-mail: hrm1{at}cam.ac.uk

Abbreviations: Rh*, photoisomerized rhodopsin


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
 JGPHome page
L. A. Astakhova, M. L. Firsov, and V. I. Govardovskii
Kinetics of Turn-offs of Frog Rod Phototransduction Cascade
J. Gen. Physiol., November 1, 2008; 132(5): 587 - 604.
[Abstract] [Full Text] [PDF]

Home page
 JGPHome page
C. L. Makino, R.L. Dodd, J. Chen, M.E. Burns, A. Roca, M.I. Simon, and D.A. Baylor
Recoverin Regulates Light-dependent Phosphodiesterase Activity in Retinal Rods
J. Gen. Physiol., June 1, 2004; 123(6): 729 - 741.
[Abstract] [Full Text] [PDF]

Home page
 JGPHome page
C. M. Krispel, C.-K. Chen, M. I. Simon, and M. E. Burns
Novel Form of Adaptation in Mouse Retinal Rods Speeds Recovery of Phototransduction
J. Gen. Physiol., November 24, 2003; 122(6): 703 - 712.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
C. M. Krispel, C.-K. Chen, M. I. Simon, and M. E. Burns
Prolonged Photoresponses and Defective Adaptation in Rods of G{beta}5-/- Mice
J. Neurosci., August 6, 2003; 23(18): 6965 - 6971.
[Abstract] [Full Text] [PDF]

Home page
 JGPHome page
H. R. Matthews, M.C. Cornwall, and R.K. Crouch
Prolongation of Actions of Ca2+ Early in Phototransduction by 9-Demethylretinal
J. Gen. Physiol., October 1, 2001; 118(4): 377 - 390.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
G. L. Fain, H. R. Matthews, M. C. Cornwall, and Y. Koutalos
Adaptation in Vertebrate Photoreceptors
Physiol Rev, January 1, 2001; 81(1): 117 - 151.
[Abstract] [Full Text] [PDF]

Home page
 JGPHome page
S. Nikonov, T.D. Lamb, and E.N. Pugh Jr.
The Role of Steady Phosphodiesterase Activity in the Kinetics and Sensitivity of the Light-Adapted Salamander Rod Photoresponse
J. Gen. Physiol., December 1, 2000; 116(6): 795 - 824.
[Abstract] [Full Text] [PDF]

Home page
 JGPHome page
T. I. Rebrik, E. A. Kotelnikova, and J. I. Korenbrot
Time Course and Ca2+ Dependence of Sensitivity Modulation in Cyclic Gmp-Gated Currents of Intact Cone Photoreceptors
J. Gen. Physiol., October 1, 2000; 116(4): 521 - 534.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
M. A. Erickson, L. Lagnado, S. Zozulya, T. A. Neubert, L. Stryer, and D. A. Baylor
The effect of recombinant recoverin on the photoresponse of truncated rod photoreceptors
PNAS, May 26, 1998; 95(11): 6474 - 6479.
[Abstract] [Full Text] [PDF]

Home page
 JGPHome page
S. Nikonov, N. Engheta, and E.N. Pugh Jr.
Kinetics of Recovery of the Dark-adapted Salamander Rod Photoresponse
J. Gen. Physiol., January 1, 1998; 111(1): 7 - 37.
[Abstract] [Full Text] [PDF]


  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents