Human Salt Taste and the Lingual Surface Potential Correlate

• Published in: Chemical senses 2009-06, Vol.34 (5), p.373-382
• Main Authors: Feldman, George M., Heck, Gerard L., Smith, Nancy L.
• Format: Article
• Language: English
• Subjects: Adult; amiloride; Amiloride - pharmacology; Biological and medical sciences; Electrodes; electrophysiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Membrane Potentials - drug effects; Middle Aged; Olfaction. Taste; Perception; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; salt taste; Signal Transduction; Sodium Channel Blockers - pharmacology; Sodium Channels - metabolism; Sodium Chloride - chemistry; Sodium Chloride - pharmacology; Taste - physiology; Tongue - physiology
• ISSN: 0379-864X; 1464-3553
• DOI: 10.1093/chemse/bjp009

We have demonstrated in humans that Na+ evokes changes in the lingual surface potential (LSP) using a custom chamber. To assess whether a relationship exists between the Na+-evoked changes in the LSP and the intensity of salt taste, we measured the LSP and the intensity of salt taste simultaneously in 7 subjects using test solutions (50, 100, 300, and 1000 mM NaCl) presented in random order. The evoked LSPs and intensity scores correlated with one another well (r2 = 0.992, P < 0.01). We then screened 14 subjects for their ability to discriminate between 100 and 300 mM NaCl using the chamber. Three subjects were consistently capable of distinguishing the salt concentrations. In these 3 subjects, an inhibitor of the epithelial sodium channel, amiloride (10 μM), blocked the ability to distinguish salt concentrations and affected the LSP. These data suggest that the LSP may be a component of the signal transduction system involved in human salt taste. In adept salt tasters, an amiloride-sensitive mechanism appears to have a role in distinguishing salt concentrations.