Physiological Reviews, Vol 66, 772-818, Copyright © 1986 by American Physiological Society

JOURNAL ARTICLE

Functional properties of vertebrate olfactory receptor neurons

T. V. Getchell

The interaction of an odorant with the chemosensitive membrane of olfactory receptor neurons initiates a sequence of molecular and membrane events leading to sensory transduction, impulse initiation, and the transmission of sensory information to the brain. The main steps in this sequence are summarized in Figure 6. Several lines of evidence support the hypothesis that the initial molecular events and subsequent stages of transduction are mediated by odorant receptor sites and associated ion channels located in the membrane of the cilia and apical dendritic knob of the olfactory receptor neuron. Similarly, the membrane events associated with impulse initiation and propagation are mediated by voltage-gated channels located in the initial axonal segment and the axolemma. The ionic and electrical events associated with the proposed sequence have been characterized in general using a variety of experimental techniques. The identification, localization, and sequence of membrane events are consistent with the neurophysiological properties observed in specific regions of the bipolar receptor neuron. The influence of other cells in the primary olfactory pathway such as the sustentacular cells in the olfactory epithelium, the Schwann cells in the olfactory nerve, and the astrocytes in the olfactory nerve layer in the olfactory bulb on the physiological activity of the olfactory receptor neuron is an emerging area of research interests. The general principles derived from the experimental results described in this review provide only a framework that is both incomplete and of necessity somewhat speculative. As noted in the Introduction, the multidisciplinary study of the primary olfactory pathway is undergoing a renaissance of research interest. The application of modern biophysical, cell, and molecular biological techniques to the basic issues of odorant recognition and membrane excitability will clarify the speculations and lead to the establishment of new hypotheses. Three broad areas of research will benefit from such studies. First, the application of biophysical techniques will lead to a detailed characterization of the membrane properties and associated ion conductance mechanisms. Second, the isolation and biochemical characterization of intrinsic membrane and cytosolic proteins associated with odorant recognition, sensory transduction, and the subsequent electrical events will result from the utilization of cell and molecular biological techniques.(ABSTRACT TRUNCATED AT 400 WORDS)

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]

				P.-M. Lledo, G. Gheusi, and J.-D. Vincent Information Processing in the Mammalian Olfactory System Physiol Rev, January 1, 2005; 85(1): 281 - 317. [Abstract] [Full Text] [PDF]

				R. W. Friedrich and G. Laurent Dynamics of Olfactory Bulb Input and Output Activity During Odor Stimulation in Zebrafish J Neurophysiol, June 1, 2004; 91(6): 2658 - 2669. [Abstract] [Full Text] [PDF]

				C. C. Hegg, D. Greenwood, W. Huang, P. Han, and M. T. Lucero Activation of Purinergic Receptor Subtypes Modulates Odor Sensitivity J. Neurosci., September 10, 2003; 23(23): 8291 - 8301. [Abstract] [Full Text] [PDF]

				R. Delgado, M. V. Saavedra, O. Schmachtenberg, J. Sierralta, and J. Bacigalupo Presence of Ca2+-Dependent K+ Channels in Chemosensory Cilia Support a Role in Odor Transduction J Neurophysiol, September 1, 2003; 90(3): 2022 - 2028. [Abstract] [Full Text] [PDF]

				H. Yamada and K. Nakatani Odorant-induced Hyperpolarization and Suppression of cAMP-activated Current in Newt Olfactory Receptor Neurons Chem Senses, January 1, 2001; 26(1): 25 - 34. [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]

				K. M. Dorries and J. S. Kauer Relationships Between Odor-Elicited Oscillations in the Salamander Olfactory Epithelium and Olfactory Bulb J Neurophysiol, February 1, 2000; 83(2): 754 - 765. [Abstract] [Full Text] [PDF]

				J. Hosler and B. Smith Blocking and the detection of odor components in blends J. Exp. Biol., January 9, 2000; 203(18): 2797 - 2806. [Abstract] [PDF]

				G. Laurent A Systems Perspective on Early Olfactory Coding Science, October 22, 1999; 286(5440): 723 - 728. [Abstract] [Full Text]

				T. A. Cleland and C. Linster Concentration Tuning Mediated by Spare Receptor Capacity in Olfactory Sensory Neurons: A Theoretical Study Neural Comput., October 1, 1999; 11(7): 1673 - 1690. [Abstract] [Full Text]

				C Vogler and D Schild Inhibitory and excitatory responses of olfactory receptor neurons of xenopus laevis tadpoles to stimulation with amino acids J. Exp. Biol., January 4, 1999; 202(8): 997 - 1003. [Abstract] [PDF]

				F. Zufall and T. Leinders-Zufall Identification of a Long-Lasting Form of Odor Adaptation that Depends on the Carbon Monoxide/cGMP SecondMessenger System J. Neurosci., April 15, 1997; 17(8): 2703 - 2712. [Abstract] [Full Text] [PDF]

				D Restrepo, T Miyamoto, B. Bryant, and J. Teeter Odor stimuli trigger influx of calcium into olfactory neurons of the channel catfish Science, September 7, 1990; 249(4973): 1166 - 1168. [Abstract] [PDF]