Vallate papillae

FIGURE 50-7 Rattongue, taste papillae and taste buds. (A) Surface of the rat tongue showing location of the taste papillae. (B) Cross-section of the three main types of taste papillae fungiform, foliate and vallate. (C) The taste bud contains 50-100 taste cells, including receptor cells and basal cells. 

Sour taste detects acids, i.e., protons. Several different sour taste receptor candidates such as acid-sensing ion channels (ASICs) (57), hyperpolarization-activated cyclic nucleotide-gated channels (HCNs) (58), and two pore domain potassium channels (K2PS) (59, 60) have been described in the past. In addition, recent research identified two members of the polycystic kidney disease (PKD) family of the transient receptor potential superfamily (TRP) as strong sour taste receptor candidates or as part thereof. Immunohistochemistry and in situ hybridization revealed the presence of the polycystic-kidney-disease-like ion channel PKD2L1 in subsets of taste receptor cells of mouse fungiform, vallate, and foliate papillae. These cells differ from... 

San Gabriel A, Uneyama H, Yoshie S, Torii K. Cloning and characterization of a novel mGluRl variant from vallate papillae that functions as a receptor for L-glutamate stimuli. Chem. Senses 2005 30 i2-i26. 

Fukuwatari T, Kawada T, Tsuruta M, Hiraoka T, Iwanaga T, Sugimoto E, Fushiki T (1997) Expression of the putative membrane fatty acid transporter (FAT) in taste buds of the circum-vallate papillae in rats. FEBS Lett 414 461-464... 

They tested the effect of gambierol on taste buds from mouse vallate papilla by using the patch-clamp technique to monitor membrane ion currents. These excitable cells are believed to be sensory cells able to detect food chemicals, so alterations on the ionic currents produced by the toxin could affect the signal transduction and processing. 

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