A psychophysical and electrophysiological analysis of salt taste in Trpv1 null mice

Yada Treesukosol, Vijay Lyall, Gerard L. Heck, John A. DeSimone, Alan C. Spector

Research output: Contribution to journalArticle

Abstract

Current evidence suggests salt taste transduction involves at least two mechanisms, one that is amiloride sensitive and appears to use apically located epithelial sodium channels relatively selective for Na+ and a second that is amiloride insensitive and uses a variant of the transient receptor potential vanilloid receptor 1 (TRPV1) that serves as a nonspecific cation channel. To provide a functional context for these findings, we trained Trpv1 knockout (KO) and wild-type (WT) C57BL/6J mice (n = 9 or 10/group) in a two-response operant discrimination procedure and measured detection thresholds to NaCl and KCl with and without amiloride. The KO and WT mice had similar detection thresholds for NaCl and KCl. Amiloride shifted the NaCl sensitivity curve to the same degree in both groups and had virtually no effect on KCl thresholds. In addition, a more detailed analysis of chorda tympani nerve (CT) responses to NaCl, with and without benzamil (Bz, an amiloride analog) treatment revealed that the tonic portion of the CT response of KO mice to NaCl + Bz was absent, but both KO and WT mice displayed some degree of a phasic response to NaCl with and without Bz. Because these transients constitute the entire CT response to NaCl + Bz in Trpv1 KO mice, it is possible that these signals are sufficient to maintain normal NaCl detectabilty in the behavioral task used here. Additionally, there may be other amiloride-insensitive salt transduction mechanisms in taste receptor fields other than the anterior tongue that maintain normal salt detection performance in the KO mice.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume292
Issue number5
DOIs
StatePublished - May 2007
Externally publishedYes

Fingerprint

Amiloride
Knockout Mice
Chorda Tympani Nerve
Salts
Epithelial Sodium Channels
Inbred C57BL Mouse
Tongue
Cations

Keywords

  • C57BL/6 mice
  • Chorda tympani nerve
  • Gustatory system
  • Taste ion channels
  • Vanilloid receptors

ASJC Scopus subject areas

  • Physiology

Cite this

A psychophysical and electrophysiological analysis of salt taste in Trpv1 null mice. / Treesukosol, Yada; Lyall, Vijay; Heck, Gerard L.; DeSimone, John A.; Spector, Alan C.

In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 292, No. 5, 05.2007.

Research output: Contribution to journalArticle

Treesukosol, Yada ; Lyall, Vijay ; Heck, Gerard L. ; DeSimone, John A. ; Spector, Alan C. / A psychophysical and electrophysiological analysis of salt taste in Trpv1 null mice. In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology. 2007 ; Vol. 292, No. 5.
@article{82aa796501784cf89cc823f1f2de5ae2,
title = "A psychophysical and electrophysiological analysis of salt taste in Trpv1 null mice",
abstract = "Current evidence suggests salt taste transduction involves at least two mechanisms, one that is amiloride sensitive and appears to use apically located epithelial sodium channels relatively selective for Na+ and a second that is amiloride insensitive and uses a variant of the transient receptor potential vanilloid receptor 1 (TRPV1) that serves as a nonspecific cation channel. To provide a functional context for these findings, we trained Trpv1 knockout (KO) and wild-type (WT) C57BL/6J mice (n = 9 or 10/group) in a two-response operant discrimination procedure and measured detection thresholds to NaCl and KCl with and without amiloride. The KO and WT mice had similar detection thresholds for NaCl and KCl. Amiloride shifted the NaCl sensitivity curve to the same degree in both groups and had virtually no effect on KCl thresholds. In addition, a more detailed analysis of chorda tympani nerve (CT) responses to NaCl, with and without benzamil (Bz, an amiloride analog) treatment revealed that the tonic portion of the CT response of KO mice to NaCl + Bz was absent, but both KO and WT mice displayed some degree of a phasic response to NaCl with and without Bz. Because these transients constitute the entire CT response to NaCl + Bz in Trpv1 KO mice, it is possible that these signals are sufficient to maintain normal NaCl detectabilty in the behavioral task used here. Additionally, there may be other amiloride-insensitive salt transduction mechanisms in taste receptor fields other than the anterior tongue that maintain normal salt detection performance in the KO mice.",
keywords = "C57BL/6 mice, Chorda tympani nerve, Gustatory system, Taste ion channels, Vanilloid receptors",
author = "Yada Treesukosol and Vijay Lyall and Heck, {Gerard L.} and DeSimone, {John A.} and Spector, {Alan C.}",
year = "2007",
month = "5",
doi = "10.1152/ajpregu.00587.2006",
language = "English (US)",
volume = "292",
journal = "American Journal of Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "5",

}

TY - JOUR

T1 - A psychophysical and electrophysiological analysis of salt taste in Trpv1 null mice

AU - Treesukosol, Yada

AU - Lyall, Vijay

AU - Heck, Gerard L.

AU - DeSimone, John A.

AU - Spector, Alan C.

PY - 2007/5

Y1 - 2007/5

N2 - Current evidence suggests salt taste transduction involves at least two mechanisms, one that is amiloride sensitive and appears to use apically located epithelial sodium channels relatively selective for Na+ and a second that is amiloride insensitive and uses a variant of the transient receptor potential vanilloid receptor 1 (TRPV1) that serves as a nonspecific cation channel. To provide a functional context for these findings, we trained Trpv1 knockout (KO) and wild-type (WT) C57BL/6J mice (n = 9 or 10/group) in a two-response operant discrimination procedure and measured detection thresholds to NaCl and KCl with and without amiloride. The KO and WT mice had similar detection thresholds for NaCl and KCl. Amiloride shifted the NaCl sensitivity curve to the same degree in both groups and had virtually no effect on KCl thresholds. In addition, a more detailed analysis of chorda tympani nerve (CT) responses to NaCl, with and without benzamil (Bz, an amiloride analog) treatment revealed that the tonic portion of the CT response of KO mice to NaCl + Bz was absent, but both KO and WT mice displayed some degree of a phasic response to NaCl with and without Bz. Because these transients constitute the entire CT response to NaCl + Bz in Trpv1 KO mice, it is possible that these signals are sufficient to maintain normal NaCl detectabilty in the behavioral task used here. Additionally, there may be other amiloride-insensitive salt transduction mechanisms in taste receptor fields other than the anterior tongue that maintain normal salt detection performance in the KO mice.

AB - Current evidence suggests salt taste transduction involves at least two mechanisms, one that is amiloride sensitive and appears to use apically located epithelial sodium channels relatively selective for Na+ and a second that is amiloride insensitive and uses a variant of the transient receptor potential vanilloid receptor 1 (TRPV1) that serves as a nonspecific cation channel. To provide a functional context for these findings, we trained Trpv1 knockout (KO) and wild-type (WT) C57BL/6J mice (n = 9 or 10/group) in a two-response operant discrimination procedure and measured detection thresholds to NaCl and KCl with and without amiloride. The KO and WT mice had similar detection thresholds for NaCl and KCl. Amiloride shifted the NaCl sensitivity curve to the same degree in both groups and had virtually no effect on KCl thresholds. In addition, a more detailed analysis of chorda tympani nerve (CT) responses to NaCl, with and without benzamil (Bz, an amiloride analog) treatment revealed that the tonic portion of the CT response of KO mice to NaCl + Bz was absent, but both KO and WT mice displayed some degree of a phasic response to NaCl with and without Bz. Because these transients constitute the entire CT response to NaCl + Bz in Trpv1 KO mice, it is possible that these signals are sufficient to maintain normal NaCl detectabilty in the behavioral task used here. Additionally, there may be other amiloride-insensitive salt transduction mechanisms in taste receptor fields other than the anterior tongue that maintain normal salt detection performance in the KO mice.

KW - C57BL/6 mice

KW - Chorda tympani nerve

KW - Gustatory system

KW - Taste ion channels

KW - Vanilloid receptors

UR - http://www.scopus.com/inward/record.url?scp=34248170131&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34248170131&partnerID=8YFLogxK

U2 - 10.1152/ajpregu.00587.2006

DO - 10.1152/ajpregu.00587.2006

M3 - Article

C2 - 17234959

AN - SCOPUS:34248170131

VL - 292

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6135

IS - 5

ER -