|
|
||||||||
The Journal of Neurophysiology Vol. 81 No. 6 June 1999, pp. 2675-2682
Copyright ©1999 by the American Physiological Society
Department of Cell Biology, Neurobiology, and Anatomy, University of Cincinnati, Cincinnati, Ohio 45267-0521
Kleene, Steven J.
Both External and Internal Calcium Reduce the Sensitivity of the
Olfactory Cyclic-Nucleotide-Gated Channel to CAMP. J. Neurophysiol. 81: 2675-2682, 1999.
Both external and internal calcium reduce the sensitivity of the
olfactory cyclic-nucleotide-gated channel to CAMP.
In vertebrate olfaction, odorous stimuli are first transduced into an
electrical signal in the cilia of olfactory receptor neurons. Many
odorants cause an increase in ciliary cAMP, which gates cationic
channels in the ciliary membrane. The resulting influx of
Ca2+ and Na+ produces a depolarizing receptor
current. Modulation of the cyclic-nucleotide-gated (CNG) channels is
one mechanism of adjusting olfactory sensitivity. Modulation of these
channels by divalent cations was studied by patch-clamp recording from
single cilia of frog olfactory receptor neurons. In accord with
previous reports, it was found that cytoplasmic Ca2+ above
1 µM made the channels less sensitive to cAMP. The effect of
cytoplasmic Ca2+ was eliminated by holding the cilium in a
divalent-free cytoplasmic solution and was restored by adding
calmodulin (CaM). An unexpected result was that external
Ca2+ could also greatly reduce the sensitivity of the
channels to cAMP. This reduction was seen when external
Ca2+ exceeded 30 µM and was not affected by the
divalent-free solution, by CaM, or by Ca2+ buffering. The
effects of cytoplasmic and external Ca2+ were additive.
Thus the effects of cytoplasmic and external Ca2+ are
apparently mediated by different mechanisms. There was no effect of CaM
on a Ca2+-activated Cl
current that
also contributes to the receptor current. Increases in
Ca2+ concentration on either side of the ciliary membrane
may influence olfactory adaptation.
This article has been cited by other articles:
![]() |
S. J. Kleene The Electrochemical Basis of Odor Transduction in Vertebrate Olfactory Cilia Chem Senses, November 1, 2008; 33(9): 839 - 859. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. D. Weeraratne, M. Valentine, M. Cusick, R. Delay, and J. L. Van Houten Plasma Membrane Calcium Pumps in Mouse Olfactory Sensory Neurons Chem Senses, October 1, 2006; 31(8): 725 - 730. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Zimmerman The Sweet Smell of Success: Conclusive Evidence that Cyclic AMP Hydrolysis Does Not Trigger Fast Adaptation in Olfactory Receptor Cells J. Gen. Physiol., July 31, 2006; 128(2): 149 - 151. [Full Text] [PDF] |
||||
![]() |
A. Boccaccio, L. Lagostena, V. Hagen, and A. Menini Fast Adaptation in Mouse Olfactory Sensory Neurons Does Not Require the Activity of Phosphodiesterase J. Gen. Physiol., July 31, 2006; 128(2): 171 - 184. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Gomez, F. W. Lischka, M. E. Haskins, and N. E. Rawson Evidence for Multiple Calcium Response Mechanisms in Mammalian Olfactory Receptor Neurons Chem Senses, May 1, 2005; 30(4): 317 - 326. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Reisert, P. J. Bauer, K.-W. Yau, and S. Frings The Ca-activated Cl Channel and its Control in Rat Olfactory Receptor Neurons J. Gen. Physiol., August 25, 2003; 122(3): 349 - 364. [Abstract] [Full Text] [PDF] |
||||
![]() |
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] |
||||
![]() |
P. Gavazzo, C. Picco, E. Eismann, U. B. Kaupp, and A. Menini A Point Mutation in the Pore Region Alters Gating, Ca2+Blockage, and Permeation of Olfactory Cyclic Nucleotide-Gated Channels J. Gen. Physiol., September 1, 2000; 116(3): 311 - 326. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Zufall and T. Leinders-Zufall The Cellular and Molecular Basis of Odor Adaptation Chem Senses, August 1, 2000; 25(4): 473 - 481. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Kawai and E.-i. Miyachi Enhancement by T-Type Ca2+ Currents of Odor Sensitivity in Olfactory Receptor Cells J. Neurosci., May 15, 2001; 21(10): RC144 - RC144. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |