Nirupa Chaudhari

..We utilized RT-PCR, immunocytochemistry and single-cell gene expression profiling to examine the expression of the Galphaq family (q, 11, 14) in mouse taste buds...

..This review discusses the functional classes of taste cells, their cell biology, and current thinking on how taste information is transmitted to the brain...

..Collectively, these data demonstrate cross-talk between cAMP and Ca(2+) signalling in a subclass of taste cells that form synapses with gustatory fibres and may integrate tastant-evoked signals...

..Importantly, we find that P2X2 is expressed in WT taste buds and appears to function as an autocrine, positive feedback signal to amplify taste-evoked ATP secretion...

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..Mutant mice lacking OXT (OXT knockout) overconsume salty and sweet (i.e. sucrose, saccharin) solutions. We asked if OXT might also act on taste buds via its receptor, OXTR...

..Our findings suggest that ATP released during taste reception is degraded to adenosine to exert positive modulation particularly on sweet taste...

..These PLCbeta2 promoter-GFP transgenic lines promise to be useful for studying taste transduction, sensory signal processing, and taste bud development...

..Furthermore, umami responses were still observed in mutant mice lacking T1R3. A full explanation of umami taste transduction may involve novel combinations of the proposed receptors and/or as-yet-undiscovered taste receptors...

..We conclude that GABA is an inhibitory transmitter released during taste stimulation and possibly also during growth and differentiation of taste buds...

..These data demonstrate the existence of at least two molecularly distinct functional classes of taste cells: receptor cells and synapse-forming cells...

..They also indicate a route for cell-cell communication and signal processing within the taste bud...

..We propose that in taste buds, ROMK in type I/glial-like cells may serve a homeostatic function, excreting excess K(+) through the apical pore, and allowing excitable taste cells to maintain a hyperpolarized resting membrane potential...

..J. Comp. Neurol. 517:1-14, 2009. (c) 2009 Wiley-Liss, Inc...

..e. in their native physiological context. Reporter expression in other tissues (such as the heart) where cAMP plays a critical regulatory role, will permit novel biomedical approaches...

..In summary, we postulate that aminergic presynaptic taste cells synthesize only 5-HT, whereas NE (perhaps secreted by sympathetic fibers) may be concentrated and repackaged for secretion...

..This receptor diversity may underlie the complex perception of umami, with different mixtures of amino acids, peptides, and nucleotides yielding subtly distinct taste qualities...

..Our results suggest that tastant-evoked cAMP signals are not simply a secondary consequence of calcium modulation. Instead, cAMP and released Ca2+ may represent independent second messenger signals downstream of taste receptors...

..However, our results do not unambiguously identify any one channel as the acid taste transducer...

..These studies should permit ex vivo strategies for studying development and cellular function in taste cells...

..Our results indicate that ASIC2 is not required for acid taste in mice, and that if a universal mammalian acid taste transduction mechanism exists, it likely uses other acid-sensitive receptors or ion channels...

..The following paragraphs summarize current thinking about how taste signals generally, and umami taste in particular, are processed in taste buds...

..A small number of slow-cycling cells may also exist within the perimeter of the taste bud. Based on their incidence, we hypothesize that these may be progenitors for Type III cells...

..Whether AC8 is directly involved in signal transduction of umami taste remains to be established...

..Through these aims, we hope to gain a novel perspective on voltage-gated calcium channels, which play critical roles in all neuronal systems, but have been minimally studied in taste cells to date. ..

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..Because the proteins responsible for regulation are in an accessible location, understanding these mechanisms introduces the possibility of pharmacological manipulation of aversive and appetitive taste sensations. ..

..Differential library screening will then allow us to begin defining the functional relationship between receptor and output cells. ..

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..Differential library screening will then allow us to begin defining the functional relationship between receptor and output cells. ..