QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (18) Citing Articles via Google Scholar Google Scholar Articles by Oberwinkler, J. Articles by Stavenga, D. G. Search for Related Content PubMed PubMed Citation Articles by Oberwinkler, J. Articles by Stavenga, D. G.

 Previous Article  |  Next Article 

The Journal of Neuroscience, March 1, 2000, 20(5):1701-1709

Calcium Transients in the Rhabdomeres of Dark- and Light-Adapted Fly Photoreceptor Cells

Johannes Oberwinkler and Doekele G. Stavenga

Department of Neurobiophysics, University of Groningen, NL-9747 AG Groningen, The Netherlands

The light response of fly photoreceptor cells is modulated by changes in free Ca²⁺ concentration. Fly phototransduction and most processes regulating it take place in or very close to the rhabdomere. We therefore measured the kinetics and the absolute values of the free Ca²⁺ concentration in the rhabdomere of fly photoreceptor cells in vivo by making use of the natural optics of the fly's eye. We show that Ca²⁺ flowing into the rhabdomere after light stimulation of dark-adapted cells causes fast Ca²⁺ transients that reach peak values higher than 200 µM in <20 msec. Approximately 500 msec later, the free Ca²⁺ concentration has declined again to ~20 µM. The duration of the Ca²⁺ transients becomes still shorter, and their size reduced, when the photoreceptor cell is light-adapted. This reduction in duration and size of the Ca²⁺ transients is graded with the intensity of the adapting light. The kinetics and absolute values of the free calcium concentration found to occur in the rhabdomere are suitable to mediate the fast feedback signals known to act on the fly phototransduction cascade.

Key words: phototransduction; light adaptation; Ca²⁺ transients; local Ca²⁺ signaling; Ca²⁺ feedback; fluorescent Ca²⁺ indicators

---

Copyright © 2000 Society for Neuroscience  0270-6474/00/2051701-09$05.00/0

This article has been cited by other articles:

				A. Pumir, J. Graves, R. Ranganathan, and B. I. Shraiman Systems analysis of the single photon response in invertebrate photoreceptors PNAS, July 29, 2008; 105(30): 10354 - 10359. [Abstract] [Full Text] [PDF]

				J. E. Niven, M. Vahasoyrinki, M. Juusola, and A. S. French Interactions Between Light-Induced Currents, Voltage-Gated Currents, and Input Signal Properties in Drosophila Photoreceptors J Neurophysiol, June 1, 2004; 91(6): 2696 - 2706. [Abstract] [Full Text] [PDF]

				B. Minke and B. Cook TRP Channel Proteins and Signal Transduction Physiol Rev, April 1, 2002; 82(2): 429 - 472. [Abstract] [Full Text] [PDF]

				R. C. Hardie Phototransduction in Drosophila melanogaster J. Exp. Biol., March 12, 2002; 204(20): 3403 - 3409. [Abstract] [Full Text] [PDF]

				J. Oberwinkler and D. G. Stavenga Calcium imaging demonstrates colocalization of calcium influx and extrusion in fly photoreceptors PNAS, July 18, 2000; 97(15): 8578 - 8583. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help