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

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal 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 Google Scholar Google Scholar Articles by Art, J J Articles by Fettiplace, R Search for Related Content PubMed PubMed Citation Articles by Art, J J Articles by Fettiplace, R

Physiological Laboratory, University of Cambridge.

1. Hair cells were enzymatically isolated from identified regions of the turtle basilar papilla and studied with the patch-electrode technique. The experimental aim was to relate the resonance properties seen during current injection to the membrane currents measured in the same cell under whole-cell voltage clamp. 2. Solitary hair cells had resting potentials of about -50 mV, and produced a damped oscillation in membrane potential at the onset and termination of a small current step; the resonant frequency varied from 9 to 350 Hz between cells, and was correlated with the region of papilla from which a cell had been isolated. The inferred frequency map was consistent with the tonotopic arrangement described previously in the intact papilla. 3. Depolarizations from the resting potential under voltage clamp activated a large net outward current with a steep voltage dependence, and the steady-state current-voltage relationship was strongly rectified about the resting potential. Input resistances tended to be smaller in cells with higher resonant frequencies, although there was no concurrent variation in membrane area as inferred from the cell capacitance. 4. The kinetics of the outward current evoked by a small depolarizing step depended upon the resonant frequency, fo, of the hair cell, and were slower in low-frequency cells. On repolarization to the resting potential the current decayed exponentially with a time constant that changed from 150 ms in the lowest-frequency cell to less than 1 ms in the highest-frequency one. The time constant was approximately proportional to 1/f0(2). 5. Following repolarization to different membrane potentials, the tail current was found to reverse around -80 mV, indicating that the outward current was due mainly to K+. 6. The outward current was abolished by extracellular application of 25 mM-tetraethylammonium chloride (TEA), or on exchange of Cs+ for K+ in the intracellular medium filling the recording electrode, each experiment supporting the contention that K+ is the major current carrier. Such treatments also removed the oscillations in membrane potential evoked by imposed current steps. 7. Addition of TEA or intracellular perfusion with Cs+ also revealed a fast inward current with an ionic sensitivity consistent with its being carried by Ca2+. Like the K+ current, the Ca2+ current was activated by small depolarization from the resting potential, and over this voltage range it was about five to ten times smaller than the K+ current. Its activation was more rapid than the fastest outward currents in high-frequency cells.(ABSTRACT TRUNCATED AT 400 WORDS)

This article has been cited by other articles:

				L. Nie, J. Zhu, M. A. Gratton, A. Liao, K. J. Mu, W. Nonner, G. P. Richardson, and E. N. Yamoah Molecular Identity and Functional Properties of a Novel T-Type Ca2+ Channel Cloned From the Sensory Epithelia of the Mouse Inner Ear J Neurophysiol, October 1, 2008; 100(4): 2287 - 2299. [Abstract] [Full Text] [PDF]

				W. M. Roberts and M. A. Rutherford Linear and nonlinear processing in hair cells J. Exp. Biol., June 1, 2008; 211(11): 1775 - 1780. [Abstract] [Full Text] [PDF]

				G. Schwartz and M. J. Berry 2nd Sophisticated Temporal Pattern Recognition in Retinal Ganglion Cells J Neurophysiol, April 1, 2008; 99(4): 1787 - 1798. [Abstract] [Full Text] [PDF]

				S. L. Johnson and W. Marcotti Biophysical properties of CaV1.3 calcium channels in gerbil inner hair cells J. Physiol., February 15, 2008; 586(4): 1029 - 1042. [Abstract] [Full Text] [PDF]

				T. A. Ghanem, K. D. Breneman, R. D. Rabbitt, and H. M. Brown Ionic Composition of Endolymph and Perilymph in the Inner Ear of the Oyster Toadfish, Opsanus tau Biol. Bull., February 1, 2008; 214(1): 83 - 90. [Abstract] [Full Text] [PDF]

				S. Lee, O. Briklin, H. Hiel, and P. Fuchs Calcium-dependent inactivation of calcium channels in cochlear hair cells of the chicken J. Physiol., September 15, 2007; 583(3): 909 - 922. [Abstract] [Full Text] [PDF]

				Y. Shen, D. Yu, H. Hiel, P. Liao, D. T. Yue, P. A. Fuchs, and T. W. Soong Alternative Splicing of the CaV1.3 Channel IQ Domain, a Molecular Switch for Ca2+-Dependent Inactivation within Auditory Hair Cells. J. Neurosci., October 18, 2006; 26(42): 10690 - 10699. [Abstract] [Full Text] [PDF]

				C. J. Kros and M. G. Evans Tuning in to cochlear hair cells J. Physiol., October 1, 2006; 576(1): 7 - 9. [Full Text] [PDF]

				D. Oliver, A. M. Taberner, H. Thurm, M. Sausbier, C. Arntz, P. Ruth, B. Fakler, and M. C. Liberman The role of BKCa channels in electrical signal encoding in the mammalian auditory periphery. J. Neurosci., June 7, 2006; 26(23): 6181 - 6189. [Abstract] [Full Text] [PDF]

				M. J. Palmer Modulation of Ca2+-activated K+ currents and Ca2+-dependent action potentials by exocytosis in goldfish bipolar cell terminals J. Physiol., May 1, 2006; 572(3): 747 - 762. [Abstract] [Full Text] [PDF]

				H. Thurm, B. Fakler, and D. Oliver Ca2+-independent activation of BKCa channels at negative potentials in mammalian inner hair cells J. Physiol., November 15, 2005; 569(1): 137 - 151. [Abstract] [Full Text] [PDF]

				H. Samaranayake, J. C Saunders, M. I Greene, and D. S Navaratnam Ca2+ and K+ (BK) channels in chick hair cells are clustered and colocalized with apical-basal and tonotopic gradients J. Physiol., October 1, 2004; 560(1): 13 - 20. [Abstract] [Full Text] [PDF]

				K. Nakajo and Y. Okamura Development of Transient Outward Currents Coupled With Ca2+-Induced Ca2+ Release Mediates Oscillatory Membrane Potential in Ascidian Muscle Cells J Neurophysiol, August 1, 2004; 92(2): 1056 - 1066. [Abstract] [Full Text] [PDF]

				W. Marcotti, S. L. Johnson, and C. J. Kros Effects of intracellular stores and extracellular Ca2+ on Ca2+-activated K+ currents in mature mouse inner hair cells J. Physiol., June 1, 2004; 557(2): 613 - 633. [Abstract] [Full Text] [PDF]

				A. Brandt, J. Striessnig, and T. Moser CaV1.3 Channels Are Essential for Development and Presynaptic Activity of Cochlear Inner Hair Cells J. Neurosci., November 26, 2003; 23(34): 10832 - 10840. [Abstract] [Full Text] [PDF]

				S. Masetto, M. Bosica, M. J. Correia, O. P. Ottersen, G. Zucca, P. Perin, and P. Valli Na+ Currents in Vestibular Type I and Type II Hair Cells of the Embryo and Adult Chicken J Neurophysiol, August 1, 2003; 90(2): 1266 - 1278. [Abstract] [Full Text] [PDF]

				H. Bao, W. H. Wong, J. M. Goldberg, and R. A. Eatock Voltage-Gated Calcium Channel Currents in Type I and Type II Hair Cells Isolated From the Rat Crista J Neurophysiol, July 1, 2003; 90(1): 155 - 164. [Abstract] [Full Text] [PDF]

				C. M. Hackney, S. Mahendrasingam, E. M. C. Jones, and R. Fettiplace The Distribution of Calcium Buffering Proteins in the Turtle Cochlea J. Neurosci., June 1, 2003; 23(11): 4577 - 4589. [Abstract] [Full Text] [PDF]

				A. Rodriguez-Contreras and E. N. Yamoah Effects of Permeant Ion Concentrations on the Gating of L-Type Ca2+ Channels in Hair Cells Biophys. J., May 1, 2003; 84(5): 3457 - 3469. [Abstract] [Full Text] [PDF]

				J. M. Goldberg and A. M. Brichta Functional Analysis of Whole Cell Currents From Hair Cells of the Turtle Posterior Crista J Neurophysiol, December 1, 2002; 88(6): 3279 - 3292. [Abstract] [Full Text] [PDF]

				M. A. Ruggero and A. N. Temchin The roles of the external, middle, and inner ears in determining the bandwidth of hearing PNAS, October 1, 2002; 99(20): 13206 - 13210. [Abstract] [Full Text] [PDF]

				L. Robles and M. A. Ruggero Mechanics of the Mammalian Cochlea Physiol Rev, July 1, 2001; 81(3): 1305 - 1352. [Abstract] [Full Text] [PDF]

				C. Boyer, J. J. Art, C. J. Dechesne, J. Lehouelleur, J. Vautrin, and A. Sans Contribution of the Plasmalemma to Ca2+ Homeostasis in Hair Cells J. Neurosci., April 15, 2001; 21(8): 2640 - 2650. [Abstract] [Full Text] [PDF]

				M. A. Ruggero, S. S. Narayan, A. N. Temchin, and A. Recio Mechanical bases of frequency tuning and neural excitation at the base of the cochlea: Comparison of basilar-membrane vibrations and auditory-nerve-fiber responses in chinchilla PNAS, October 24, 2000; 97(22): 11744 - 11750. [Abstract] [Full Text] [PDF]

				S. Masetto, P. Perin, A. Malusa, G. Zucca, and P. Valli Membrane Properties of Chick Semicircular Canal Hair Cells In Situ During Embryonic Development J Neurophysiol, May 1, 2000; 83(5): 2740 - 2756. [Abstract] [Full Text] [PDF]

				K. Ramanathan, T. H. Michael, and P. A. Fuchs beta Subunits Modulate Alternatively Spliced, Large Conductance, Calcium-Activated Potassium Channels of Avian Hair Cells J. Neurosci., March 1, 2000; 20(5): 1675 - 1684. [Abstract] [Full Text] [PDF]

				M. S. Smotherman and P. M. Narins The Electrical Properties of Auditory Hair Cells in the Frog Amphibian Papilla J. Neurosci., July 1, 1999; 19(13): 5275 - 5292. [Abstract] [Full Text] [PDF]

				A. Meir, S. Ginsburg, A. Butkevich, S. G. Kachalsky, I. Kaiserman, R. Ahdut, S. Demirgoren, and R. Rahamimoff Ion Channels in Presynaptic Nerve Terminals and Control of Transmitter Release Physiol Rev, July 1, 1999; 79(3): 1019 - 1088. [Abstract] [Full Text] [PDF]

				S. S. Narayan, A. N. Temchin, A. Recio, and M. A. Ruggero Frequency Tuning of Basilar Membrane and Auditory Nerve Fibers in the Same Cochleae Science, December 4, 1998; 282(5395): 1882 - 1884. [Abstract] [Full Text]

				A. J. Ricci, Y-C. Wu, and R. Fettiplace The Endogenous Calcium Buffer and the Time Course of Transducer Adaptation in Auditory Hair Cells J. Neurosci., October 15, 1998; 18(20): 8261 - 8277. [Abstract] [Full Text] [PDF]

				C. E. Armstrong and W. M. Roberts Electrical Properties of Frog Saccular Hair Cells: Distortion by Enzymatic Dissociation J. Neurosci., April 15, 1998; 18(8): 2962 - 2973. [Abstract] [Full Text] [PDF]

				C. W. Morgans, O. El Far, A. Berntson, H. Wassle, and W. R. Taylor Calcium Extrusion from Mammalian Photoreceptor Terminals J. Neurosci., April 1, 1998; 18(7): 2467 - 2474. [Abstract] [Full Text] [PDF]

				M. S. Smotherman and P. M. Narins Effect of Temperature on Electrical Resonance in Leopard Frog Saccular Hair Cells J Neurophysiol, January 1, 1998; 79(1): 312 - 321. [Abstract] [Full Text] [PDF]

				C. Martinez-Dunst, R. L. Michaels, and P. A. Fuchs Release Sites and Calcium Channels in Hair Cells of the Chick's Cochlea J. Neurosci., December 1, 1997; 17(23): 9133 - 9144. [Abstract] [Full Text] [PDF]

				S. Masetto and M. J. Correia Electrophysiological Properties of Vestibular Sensory and Supporting Cells in the Labyrinth Slice Before and During Regeneration J Neurophysiol, October 1, 1997; 78(4): 1913 - 1927. [Abstract] [Full Text] [PDF]