Taste receptor cells responding with action potentials to taste stimuli and their molecular expression of taste related genes.

Recent molecular biological studies have revealed many molecular aspects of taste transduction in receptor cells for each taste categories which are referred to as salty, sweet, sour, bitter and umami in human respectively. (Lindemann, 2001; Gilbertson and Boughter, 2003). For example, ion channels such as ENaC, ASIC and HCN mediate salty and sour taste and G-protein-coupled receptors such as T1Rs and T2Rs play a key role in sweet, bitter and umami taste. However, there is little evidence for involvements of these molecules in taste reception and transduction at the cellular level. It is necessary to examine both molecular and physiological properties in single taste receptor cell. In this study, by use of loose patch recording technique combined with single cell multiplex RT–PCR, we characterized single taste cells by their responses to four basic taste stimuli and expression of taste-related molecules.