Umami Taste Signaling from the Taste Bud to Cortex

Abstract

Umami is the meaty or savory taste elicited by monosodium glutamate and other amino acids. The presence of these amino acids in foods and beverages can alter dietary intake and nutritional balance and thus the health of human and nonhuman animals. Umami has been a major culinary influence in Eastern cultures for over a century and has gradually become an important factor in Western diets. Throughout its history, research on umami, especially the unique taste elicited by monosodium glutamate and its synergistic interaction with ribonucleotides such as inosine 5′-monophosphate, has played an important role in discovering peripheral taste receptors, cellular and molecular transduction mechanisms, and the neuroanatomy of the gustatory system. Umami taste has also been a focus of study to identify brain stem and cortical structures involved in sensory processing and generating food-directed behavior. This chapter provides a brief history of umami taste, a description of the molecular receptors and cellular transduction mechanisms for umami taste stimuli in chemosensory cells in the oral cavity and gut, and an overview of the brain systems involved in umami taste perception. An understanding of these aspects of umami taste is of fundamental importance for basic science and for healthcare professions working with patient populations with dietary challenges.