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

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, March 5, 2008, 28(10):2659-2666; doi:10.1523/JNEUROSCI.4670-07.2008

This Article Full Text Full Text (PDF) Supplemental Data 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 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 Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Rospars, J.-P. Articles by Duchamp-Viret, P. Search for Related Content PubMed PubMed Citation Articles by Rospars, J.-P. Articles by Duchamp-Viret, P.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Competitive and Noncompetitive Odorant Interactions in the Early Neural Coding of Odorant Mixtures

Jean-Pierre Rospars,¹ Petr Lansky,² Michel Chaput,³ and Patricia Duchamp-Viret³

¹Institut National de la Recherche Agronomique, Unité Mixte de Recherche (UMR) 1272, Physiologie de l'Insecte and Unité Mathématiques et Informatique Appliquées, F-78000 Versailles, France, ²Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, CZ-142 20 Prague 4, Czech Republic, and ³Laboratoire de Neurosciences Sensorielles, Comportement, Cognition, Centre National de la Recherche Scientifique, UMR 5020, Université de Lyon–Lyon 1, F-69366 Lyon Cedex 07, France

Correspondence should be addressed to Dr. Jean-Pierre Rospars, Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1272, Physiologie de l'Insecte, F-78000 Versailles, France. Email: rospars{at}versailles.inra.fr

Most olfactory receptor neurons (ORNs) express a single type of olfactory receptor that is differentially sensitive to a wide variety of odorant molecules. The diversity of possible odorant-receptor interactions raises challenging problems for the coding of complex mixtures of many odorants, which make up the vast majority of real world odors. Pure competition, the simplest kind of interaction, arises when two or more agonists can bind to the main receptor site, which triggers receptor activation, although only one can be bound at a time. Noncompetitive effects may result from various mechanisms, including agonist binding to another site, which modifies the receptor properties at the main binding site. Here, we investigated the electrophysiological responses of rat ORNs in vivo to odorant agonists and their binary mixtures and interpreted them in the framework of a quantitative model of competitive interaction between odorants. We found that this model accounts for all concentration-response curves obtained with single odorants and for about half of those obtained with binary mixtures. In the other half, the shifts of curves along the concentration axis and the changes of maximal responses with respect to model predictions, indicate that noncompetitive interactions occur and can modulate olfactory receptors. We conclude that, because of their high frequency, the noncompetitive interactions play a major role in the neural coding of natural odorant mixtures. This finding implies that the CNS activity caused by mixtures will not be easily analyzed into components, and that mixture responses will be difficult to generalize across concentration.

Key words: sensory coding; olfactory receptor neuron; in vivo; signal transduction; allostery; mixture interaction

---

Received July 30, 2007; revised Dec. 17, 2007; accepted Jan. 20, 2008.

Correspondence should be addressed to Dr. Jean-Pierre Rospars, Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1272, Physiologie de l'Insecte, F-78000 Versailles, France. Email: rospars{at}versailles.inra.fr

This article has been cited by other articles:

				T. Miyazawa, M. Gallagher, G. Preti, and P. M. Wise Psychometric Functions for Ternary Odor Mixtures and Their Unmixed Components Chem Senses, November 1, 2009; 34(9): 753 - 761. [Abstract] [Full Text] [PDF]

				J. Reisert and D. Restrepo Molecular Tuning of Odorant Receptors and Its Implication for Odor Signal Processing Chem Senses, September 1, 2009; 34(7): 535 - 545. [Abstract] [Full Text] [PDF]

				K. R. Gamble and D. W. Smith Discrimination of "Odorless" Mineral Oils Alone and as Diluents by Behaviorally Trained Mice Chem Senses, September 1, 2009; 34(7): 559 - 563. [Abstract] [Full Text] [PDF]

				M. Brodin, M. Laska, and M. J. Olsson Odor Interaction between Bourgeonal and Its Antagonist Undecanal Chem Senses, September 1, 2009; 34(7): 625 - 630. [Abstract] [Full Text] [PDF]

				R. M. Carey, J. V. Verhagen, D. W. Wesson, N. Pirez, and M. Wachowiak Temporal Structure of Receptor Neuron Input to the Olfactory Bulb Imaged in Behaving Rats J Neurophysiol, February 1, 2009; 101(2): 1073 - 1088. [Abstract] [Full Text] [PDF]

				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]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help