Perception and modulation of umami taste in humans

Lucy F Donaldson
University of Bristol, UK.
 Lucy.Donaldson@bris.ac.uk

Several molecules have been suggested as receptors for umami taste over the last 10 years. The candidate umami receptors all belong to the class C family of G-protein coupled receptors and the two favoured receptors are the taste-mGluR4 receptor and the T1R1:T1R3 heterodimeric receptor. A truncated mGluR1 receptor has also been localised to taste cells. An overview of the different umami receptors will be presented.

Taste detection in humans is genetically determined, but can also be affected by mood, hunger and other environmental conditions. We have investigated the modulation of human taste by mood and by drugs that alter neurotransmitter effects, in an attempt to understand the processing of gustatory information in humans.

By disturbing serotoninergic, noradrenergic and adenosinergic systems, we have shown that different taste thresholds can be modulated, in different ways, implicating these neurotransmitters in gustatory processing. Although the current models assume that processing of umami stimuli is similar to that of bitter and sweet stimuli, our results suggest that the neurotransmitters involved in the processing of umami taste are significantly different from either bitter or sweet.