HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 93/4/1880    most recent 00303.2004v2 00303.2004v1 Alert me when this article is cited 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 (2) Citing Articles via Google Scholar Google Scholar Articles by Tomaru, A. Articles by Kurahashi, T. Search for Related Content PubMed PubMed Citation Articles by Tomaru, A. Articles by Kurahashi, T.

Mechanisms Determining the Dynamic Range of the Bullfrog Olfactory Receptor Cell

¹Department of Biophysical Engineering, Graduate School of Engineering Science; and ²Department of Frontier Biosciences, Osaka University, Toyonaka, Osaka, Japan

Submitted 5 April 2004; accepted in final form 9 November 2004

Spike discharges of single olfactory receptor cells (ORCs) were recorded with the whole cell patch-clamp method applied to slice preparation. In parallel, activities of transduction channels were measured under the voltage-clamp condition. When cells were stimulated by odorants, 54 out of 306 cells exhibited inward current responses (10 mM cineole in the puffer pipette). The amplitude of the inward current was dependent on the stimulus period, reflecting the time integration for the stimulus dose, and the relation could be fitted by the Hill equation. Under the current-clamp condition, current injection induced spike discharges. In cells showing repetitive firings, the firing frequency was dependent on the amount of injected current. The relation was fitted by the Michaelis-Menten equation showing saturation. When cells were responsive to the odorant and had abilities to discharge repetitive spikes, the depolarizing responses were accompanied by repetitive spikes. In those cells, the spike frequency was dose-dependent, expressing saturation similar to the result obtained by current injection. Since both transduction channel and spike generative steps expressed saturation in their dose dependences, we explored what step(s) actually determines saturation in ORC signaling processes. By examining dose-response relations of both the current and spikes in the same cells, saturating dose was found to be dependent largely on that of the transduction step. This suggests that the dynamic range is fundamentally determined by the transduction system. In addition, a simple model derived from the nonlinearity of the plasma membrane could explain that a critical level of dynamic range was, at least in part, modified by the membrane nonlinearity.

This article has been cited by other articles:

				S. J. Kleene The Electrochemical Basis of Odor Transduction in Vertebrate Olfactory Cilia Chem Senses, August 14, 2008; (2008) bjn048v1. [Abstract] [Full Text] [PDF]

				X. Grosmaitre, A. Vassalli, P. Mombaerts, G. M. Shepherd, and M. Ma From the Cover: Odorant responses of olfactory sensory neurons expressing the odorant receptor MOR23: A patch clamp analysis in gene-targeted mice PNAS, February 7, 2006; 103(6): 1970 - 1975. [Abstract] [Full Text] [PDF]