Journal Mobile Options
Table of Contents
Vol. 8, No. 6, 1999
Issue release date: November–December 1999
Biol Signals Recept 1999;8:360–365

Co-Localization of Epithelial Sodium Channels and Glutamate Receptors in Single Taste Cells

Lin W. · Kinnamon S.C.
aDepartment of Anatomy and Neurobiology, Colorado State University, Fort Collins, Colo., and bRocky Mountain Taste and Smell Center, University of Colorado Health Sciences Center, Denver, Colo., USA

Individual Users: Register with Karger Login Information

Please create your User ID & Password

Contact Information

I have read the Karger Terms and Conditions and agree.

To view the fulltext, please log in

To view the pdf, please log in


Umami taste is elicited by monosodium glutamate (MSG), a compound consisting of two potent taste stimuli, Na+ and glutamate. In rat fungiform taste cells, amiloride-sensitive epithelial sodium channels (ENaCs) mediate Na+ transduction, while glutamate is transduced by a combination of ionotropic and metabotropic glutamate receptors. We used giga-seal whole-cell recording to determine if responses to glutamate and Na+ occur in the same taste cells. Approximately 68% of the cells tested responded to amiloride, indicating that they express functional ENaCs. Responses to glutamate occurred in about 58% of the cells tested. Interestingly, responses to glutamate occurred in the subset of cells that also responded to amiloride, indicating that glutamate receptors are located preferentially in the same taste cells that also express ENaCs. Further experiments showed that amiloride did not suppress responses to glutamate under voltage-clamp conditions. Taken together, the data suggest that although ENaCs are not involved directly in glutamate transduction, their co-localization with glutamate receptors provides a substrate for the cellular integration of these independent pathways.

Copyright © 1999 S. Karger AG, Basel

Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.


  1. Li XJ, Blackshaw S, Snyder SH: Expression and localization of amiloride-sensitive sodium channel indicate a role for non-taste cells in taste perception. Proc Natl Acad Sci USA 1994;91:1814–1818.

    External Resources

  2. Kretz O, Barbry P, Bock R, Lindemann B: Differential expression of RNA and protein of the three pore-forming subunits of the amiloride-sensitive epithelial sodium channel in taste buds of the rat. J Histochem Cytochem 1999;47:1–14.
  3. Lin W, Finger TE, Rossier BC, Kinnamon SC: Epithelial Na+ channel subunits in rat taste cells: Localization and regulation by aldosterone. J Comp Neurol 1999;405:406–420.
  4. Heck GL, Mierson S, DeSimone JA: Salt taste transduction occurs through an amiloride-sensitive sodium transport pathway. Science 1984;233:403–405.
  5. Avenet P, Lindemann B: Amiloride-blockable sodium currents in isolated taste receptor cells. J Membr Biol 1988;105:245–255.
  6. Doolin RE, Gilbertson TA: Distribution and characterization of functional amiloride-sensitive sodium channels in rat tongue. J Gen Physiol 1996;107:545–554.
  7. Brand JG, Teeter JH, Kumazawa T, Huque T, Bayley DL: Transduction mechanisms for the taste of amino acids. Physiol Behav 1991;49:899–904.
  8. Chaudhari N, Yang H, Lamp C, Delay E, Cartford C, Than T, Roper SD: The taste of monosodium glutamate: Membrane receptors in taste buds. J Neurosci 1996;16:3817–3826.
  9. Hayashi Y, Zviman MM, Brand JG, Teeter JH, Restrepo D: Measurement of membrane potential and [Ca2+]i in cell ensembles: Application to the study of glutamate taste in mice. Biophys J 1996;71:1057–1070.
  10. Bigiani A, Delay RJ, Chaudhari N, Kinnamon SC, Roper SD: Responses to glutamate in rat taste cells. J Neurophysiol 1997;77:3048–3059.

    External Resources

  11. Lin W, Kinnamon SC: Monosodium glutamate and guanosine 5′-monophosphate responses in rat fungiform taste cells. Abstracts, Soc Neurosci 1996;22:1826.
  12. Lin W, Kinnamon SC: Responses to monosodium glutamate and guanosine 5′-monophosphate in rat fungiform taste cells. New York Acad Sci 1998;855:407–411.
  13. Ninomiya Y, Funakoshi M: Peripheral neural basis for behavioural discrimination between glutamate and the four basic taste substances in mice. Comp Biochem Physiol 1989;A92:371–376.
  14. Hellekant G, Ninomiya Y: On the taste of umami in chimpanzee. Physiol Behav 1991;49:927–934.
  15. Kumazawa T, Nakamura M, Kurihara K: Canine taste nerve responses to umami substances. Physiol Behav 1991;49:875–881.
  16. Nakamura M, Kurihara K: Canine taste nerve responses to monosodium glutamate and disodium guanylate: Differentiation between umami and salt components with amiloride. Brain Res 1991;541:21–28.
  17. Hellekant G, Danilova V, Ninomiya Y: Primate sense of taste: Behavioral and single chorda tympani and glossopharyngeal nerve fiber recordings in the rhesus monkey, Macaca mulatta. J Neurophysiol 1997;77:978–993.

    External Resources

  18. Yamamoto T, Matsuo R, Kiyomitsu Y, Kitamura R: Taste effects of ‘umami’ substances in hamsters as studied by electrophysiological and conditioned taste aversion techniques. Brain Res 1988;1993;451:147–162.
  19. Lin W, Ogura T, Kinnamon SC: Responses to monosodium glutamate and amiloride occur in single rat fungiform taste cells. Chem Senses 1996;21:632–633.
  20. Béhé P, DeSimone JA, Avenet P, Lindemann B: Membrane currents in taste cells of the rat fungiform papilla. Evidence for two types of Ca2+ currents and inhibition of K+ currents by saccharin. J Gen Physiol 1990;96:1061–1084.
  21. Kossel AH, McPheeters M, Lin W, Kinnamon SC: Development of membrane properties in taste cells of fungiform papillae: Functional evidence for early presence of amiloride-sensitive sodium channels. J Neurosci 1997;17:9634–9641.

    External Resources

  22. Hamill OP, Marty A, Neher E, Sakmann B, Sigworth FJ: Improved patch-clamp techniques for high- resolution current recording from cells and cell-free membrane patches. Pflügers Arch 1981;391:85–100.
  23. Ninomiya Y, Kurenuma S, Nomura T, Uebayashi H, Kawamura H: Taste synergism between monosodium glutamate and 5′-ribonucleotide in mice. Comp Biochem Physiol 1992;A101:97–102.
  24. Yamaguchi S, Kobori I: Humans and appreciation of the umami taste; in Kurihara K, Suzuki N, Ogawa H (eds): Olfaction and Taste XI. Springer, Tokyo, pp 353–356.
  25. Jain S, Roper SD: Immunocytochemistry of gamma-aminobutyric acid, glutamate, serotonin, and histamine in Necturus taste buds. J Comp Neurol 1991;307:675–682.

    External Resources

Pay-per-View Options
Direct payment This item at the regular price: USD 38.00
Payment from account With a Karger Pay-per-View account (down payment USD 150) you profit from a special rate for this and other single items.
This item at the discounted price: USD 26.50