Taste Preference Synergy Between Glutamate Receptor Agonists and Inosine Monophosphate in Rats
Monosodium glutamate (MSG) elicits a taste called umami and interacts synergistically with nucleotide monophosphates such as 5′-inosine monophosphate (IMP) to potentiate this taste intensity. Indeed, the synergistic interaction of nucleotide monophosphates and MSG is a hallmark of umami. We examined...
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Published in | Chemical senses Vol. 25; no. 5; pp. 507 - 515 |
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Main Authors | , , , , , , |
Format | Journal Article Conference Proceeding |
Language | English |
Published |
Oxford
Oxford University Press
01.10.2000
Oxford Publishing Limited (England) |
Subjects | |
Online Access | Get full text |
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Summary: | Monosodium glutamate (MSG) elicits a taste called umami and interacts synergistically with nucleotide monophosphates such as 5′-inosine monophosphate (IMP) to potentiate this taste intensity. Indeed, the synergistic interaction of nucleotide monophosphates and MSG is a hallmark of umami. We examined interactions between MSG and other taste stimuli, including IMP, by measuring the lick rates of non-deprived rats during 30 s trials. To control for non-linear psychophysical functions, the concentration of one taste stimulus in a binary mixture was systematically increased while the concentration of the second taste stimulus was decreased (stimulus substitution method). Synergy between two stimuli was detected if the lick rate for a binary mixture exceeded that expected from the sum of the lick rates for each stimulus alone. In initial experiments, taste synergy was observed when rats were presented with mixtures of MSG and IMP but not with mixtures of MSG and sucrose. In subsequent experiments, glutamate receptor agonists other than MSG were presented with IMP to test for taste synergy. No evidence of synergy was seen when rats were presented with mixtures of IMP and kainic acid or IMP and N-methyl-d-aspartate. However, taste synergy between IMP and l-AP4, a potent agonist at mGluR4 receptors, was observed. These results suggest that a metabotropic glutamate receptor similar to mGluR4 may be involved in the taste synergy that characterizes umami. |
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Bibliography: | ark:/67375/HXZ-XL2HX8NK-2 Correspondence to be sent to: E.R. Delay, Department of Psychology, Regis University, 3333 Regis Boulevard, Denver, CO 80221, USA. e-mail: edelay@regis.edu local:0507.gml PII:1464-3553 istex:0EE9B2DC132542C1A9320D9A17E3A01A8FF15166 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0379-864X 1464-3553 1464-3553 |
DOI: | 10.1093/chemse/25.5.507 |