9317720 Mierson Several functional properties of receptor cells for taste in mammals are unknown. Although most of our knowledge of taste behavior, central anatomy, and nerve physiology comes from mammalian studies, amphibian taste receptor properties are far better known because these cells are much larger than those in mammals, and so are more accessible to microelectrodes. This SGER project develops a new method for measuring the intracellular voltages and ion concentrations in mammalian taste cells, to explore these unknown properties. An approach from the basal side of the taste bud makes it possible to visually identify taste bud cells, and to chemically and electrically manipulate the tissue from both the basal side facing the nerves, and the apical side facing the tastant stimuli. Results allow testing a mathematical model of the biophysics and mechanisms of adaptation in taste receptors. The technological difficulty of the new approach presents risks, but allows testing the novel hypothesis that sensory adaptation in mammalian taste occurs within these receptor cells, rather than in the nerve. The impact of this work extends beyond taste and chemosensory neurophysiology, to the field of epithelial physiology where the relation of intracellular to trans-epithelial currents is important, and to computational modeling in biology. ***
