Sensory attributes of complex tasting divalent salts are mediated by TRPM5 and TRPV1 channels.

Published

Journal Article

Complex tasting divalent salts (CTDS) are present in our daily diet, contributing to multiple poorly understood taste sensations. CTDS evoking metallic, bitter, salty, and astringent sensations include the divalent salts of iron, zinc, copper, and magnesium. To identify pathways involved with the complex perception of the above salts, taste preference tests (two bottles, brief access) were performed in wild-type (WT) mice and in mice lacking (1) the T1R3 receptor, (2) TRPV1, the capsaicin receptor, or (3) the TRPM5 channel, the latter being necessary for the perception of sweet, bitter, and umami tasting stimuli. At low concentrations, FeSO(4) and ZnSO(4) were perceived as pleasant stimuli by WT mice, and this effect was fully reversed in TRPM5 knock-out mice. In contrast, MgSO(4) and CuSO(4) were aversive to WT mice, but for MgSO(4) the aversion was abolished in TRPM5 knock-out animals, and for CuSO(4), aversion decreased in both TRPV1- and TRPM5-deficient animals. Behavioral tests revealed that the T1R3 subunit of the sweet and umami receptors is implicated in the hedonically positive perception of FeSO(4) and ZnSO(4). For high concentrations of CTDS, the omission of TRPV1 reduced aversion. Imaging studies on heterologously expressed TRPM5 and TRPV1 channels are consistent with the behavioral experiments. Together, these results rationalize the complexity of metallic taste by showing that at low concentrations, compounds such as FeSO(4) and ZnSO(4) stimulate the gustatory system through the hedonically positive T1R3-TRPM5 pathway, and at higher concentrations, their aversion is mediated, in part, by the activation of TRPV1.

Full Text

Duke Authors

Cited Authors

  • Riera, CE; Vogel, H; Simon, SA; Damak, S; le Coutre, J

Published Date

  • February 25, 2009

Published In

Volume / Issue

  • 29 / 8

Start / End Page

  • 2654 - 2662

PubMed ID

  • 19244541

Pubmed Central ID

  • 19244541

Electronic International Standard Serial Number (EISSN)

  • 1529-2401

Digital Object Identifier (DOI)

  • 10.1523/JNEUROSCI.4694-08.2009

Language

  • eng

Conference Location

  • United States