A method for in-situ tight-seal recordings from single taste bud cells of mice

In order to investigate taste transduction mechanisms, we developed a method to irrigate the receptor and basolateral membranes of mouse taste bud cells with different solutions under tight-seal recording conditions. A peeled tongue epithelium with taste bud cells was mounted on a recording platform designed to separate irrigating solutions for each membrane. The mucosal surface (receptor membrane side) of the peeled epithelium facing an inner chamber was always irrigated with deionized water or stimulating solutions, and the serosal surface (basolateral membrane side) was irrigated with a physiological saline solution. A recording electrode was placed on the basolateral membrane of a taste bud cell under an upright-microscope with a x 40-water-immersed objective. Investigated taste bud cells generated action potentials, and 1 M glucose, 200 mM NaCl, and 10 mM quinine elicited inward current. Irrigation with deionized water for more than 1 h had no effect. The resistance of the peeled tongue epithelium was 1570 +/- 343 omega cm2. These results show that the peeled tongue epithelium protects basolateral membranes from deionized water or stimulating solutions as the tongue epithelium does in situ and that this method is suitable to investigate the role of each membrane in taste transduction.