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

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, September 8, 2004, 24(36):7814-7820; doi:10.1523/JNEUROSCI.2102-04.2004

This Article Full Text Full Text (PDF) 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 (32) Citing Articles via Google Scholar Google Scholar Articles by Katz, E. Articles by Glowatzki, E. Search for Related Content PubMed PubMed Citation Articles by Katz, E. Articles by Glowatzki, E.

 Previous Article  |  Next Article 

Cellular/Molecular
Developmental Regulation of Nicotinic Synapses on Cochlear Inner Hair Cells

Eleonora Katz,^1,2 Ana Belén Elgoyhen,¹ María E. Gómez-Casati,¹ Marlies Knipper,³ Douglas E. Vetter,⁴ Paul A. Fuchs,⁵ and Elisabeth Glowatzki⁵

¹Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires (UBA), ²Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, UBA, 1428 Buenos Aires, Argentina, ³Hearing Research Center Tübingen, 72076 Tübingen, Germany, ⁴Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, and ⁵Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland 21205-2195

In the mature cochlea, inner hair cells (IHCs) transduce acoustic signals into receptor potentials, communicating to the brain by synaptic contacts with afferent fibers. Before the onset of hearing, a transient efferent innervation is found on IHCs, mediated by a nicotinic cholinergic receptor that may contain both 9 and 10 subunits. Calcium influx through that receptor activates calcium-dependent (SK2-containing) potassium channels. This inhibitory synapse is thought to disappear after the onset of hearing [after postnatal day 12 (P12)]. We documented this developmental transition using whole-cell recordings from IHCs in apical turns of the rat organ of Corti. Acetylcholine elicited ionic currents in 88-100% of IHCs between P3 and P14, but in only 1 of 11 IHCs at P16-P22. Potassium depolarization of efferent terminals caused IPSCs in 67% of IHCs at P3, in 100% at P7-P9, in 93% at P10-P12, but in only 40% at P13-P14 and in none of the IHCs tested between P16 and P22. Earlier work had shown by in situ hybridization that 9 mRNA is expressed in adult IHCs but that10 mRNA disappears after the onset of hearing. In the present study, antibodies to10 and to the associated calcium-dependent (SK2) potassium channel showed a similar developmental loss. The correlated expression of these gene products with functional innervation suggests that Alpha10 and SK2, but not Alpha9, are regulated by synaptic activity. Furthermore, this developmental knock-out of 10, but not 9, supports the hypothesis that functional nicotinic acetylcholine receptors in hair cells are heteromers containing both these subunits.

Key words: IHC; mammalian cochlea; cholinergic; efferent innervation; 910 nAChR; transient synapse; Ca²⁺-activated K⁺ channel; neonatal development

---

Received Feb 10, 2004; revised July 20, 2004; accepted July 20, 2004.

This article has been cited by other articles:

				J. Neef, A. Gehrt, A. V. Bulankina, A. C. Meyer, D. Riedel, R. G. Gregg, N. Strenzke, and T. Moser The Ca2+ Channel Subunit {beta}2 Regulates Ca2+ Channel Abundance and Function in Inner Hair Cells and Is Required for Hearing J. Neurosci., August 26, 2009; 29(34): 10730 - 10740. [Abstract] [Full Text] [PDF]

				J.-H. Kong, J. P. Adelman, and P. A. Fuchs Expression of the SK2 calcium-activated potassium channel is required for cholinergic function in mouse cochlear hair cells J. Physiol., November 15, 2008; 586(22): 5471 - 5485. [Abstract] [Full Text] [PDF]

				D. E. Vetter, E. Katz, S. F. Maison, J. Taranda, S. Turcan, J. Ballestero, M. C. Liberman, A. B. Elgoyhen, and J. Boulter The {alpha}10 nicotinic acetylcholine receptor subunit is required for normal synaptic function and integrity of the olivocochlear system PNAS, December 18, 2007; 104(51): 20594 - 20599. [Abstract] [Full Text] [PDF]

				S. L. Johnson, J. P. Adelman, and W. Marcotti Genetic deletion of SK2 channels in mouse inner hair cells prevents the developmental linearization in the Ca2+ dependence of exocytosis J. Physiol., September 1, 2007; 583(2): 631 - 646. [Abstract] [Full Text] [PDF]

				G. Sendin, A. V. Bulankina, D. Riedel, and T. Moser Maturation of Ribbon Synapses in Hair Cells Is Driven by Thyroid Hormone J. Neurosci., March 21, 2007; 27(12): 3163 - 3173. [Abstract] [Full Text] [PDF]

				O. Akil, J. Chang, H. Hiel, J.-H. Kong, E. Yi, E. Glowatzki, and L. R. Lustig Progressive Deafness and Altered Cochlear Innervation in Knock-Out Mice Lacking Prosaposin J. Neurosci., December 13, 2006; 26(50): 13076 - 13088. [Abstract] [Full Text] [PDF]

				W. Marcotti, A. Erven, S. L. Johnson, K. P. Steel, and C. J. Kros Tmc1 is necessary for normal functional maturation and survival of inner and outer hair cells in the mouse cochlea J. Physiol., August 1, 2006; 574(3): 677 - 698. [Abstract] [Full Text] [PDF]

				P. V. Plazas, E. Katz, M. E. Gomez-Casati, C. Bouzat, and A. B. Elgoyhen Stoichiometry of the {alpha}9{alpha}10 Nicotinic Cholinergic Receptor J. Neurosci., November 23, 2005; 25(47): 10905 - 10912. [Abstract] [Full Text] [PDF]

				J. A. Ballestero, P. V. Plazas, S. Kracun, M. E. Gomez-Casati, J. Taranda, C. V. Rothlin, E. Katz, N. S. Millar, and A. B. Elgoyhen Effects of Quinine, Quinidine, and Chloroquine on {alpha}9{alpha}10 Nicotinic Cholinergic Receptors Mol. Pharmacol., September 1, 2005; 68(3): 822 - 829. [Abstract] [Full Text] [PDF]

				J. M. McIntosh, P. V. Plazas, M. Watkins, M. E. Gomez-Casati, B. M. Olivera, and A. B. Elgoyhen A Novel {alpha}-Conotoxin, PeIA, Cloned from Conus pergrandis, Discriminates between Rat {alpha}9{alpha}10 and {alpha}7 Nicotinic Cholinergic Receptors J. Biol. Chem., August 26, 2005; 280(34): 30107 - 30112. [Abstract] [Full Text] [PDF]

				J. D. Goutman, P. A. Fuchs, and E. Glowatzki Facilitating efferent inhibition of inner hair cells in the cochlea of the neonatal rat J. Physiol., July 1, 2005; 566(1): 49 - 59. [Abstract] [Full Text] [PDF]

				M. E. Gomez-Casati, P. A Fuchs, A. B. Elgoyhen, and E. Katz Biophysical and pharmacological characterization of nicotinic cholinergic receptors in rat cochlear inner hair cells J. Physiol., July 1, 2005; 566(1): 103 - 118. [Abstract] [Full Text] [PDF]

				R. Dawkins, S. L. Keller, and W. F. Sewell Pharmacology of Acetylcholine-Mediated Cell Signaling in the Lateral Line Organ Following Efferent Stimulation J Neurophysiol, May 1, 2005; 93(5): 2541 - 2551. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help