expressing cells are found in circumvallate papillae and foliate papillae near the back of the tongue and palate taste receptor cells in the roof of the mouth. These cells are shown to synapse upon the glossopharyngeal nerves to send their signals to the brain. TAS1R and TAS2R (bitter) channels are not expressed together in any taste buds. References Further reading External links TAS1R3 Gene TASTE RECEPTOR TYPE 1, MEMBER 3; TAS1R3 Human taste receptors