Extracellular protons activate K+ current in a subpopulation of frog taste receptor cells.
Based on morphological and electrophysiological criteria, two distinct subpopulations (group A and group B) taste receptor cells (TRCs) isolated from frog (Rana temporaria) taste disks were identified. TRCs from the group A were depolarized by acid stimuli which, in contrast, caused hyperpolarizing responses in group B TRCs. By using patch clamp technique we explored ion mechanisms mediating the pH dependent TRC hyperpolarization, and found that K+ conductance of TRCs from the group B increased as bath solution pH reduced. Our findings provide rationale to hypothesize that TRC from the group B express H+ gated K+ channels.
D000818:Animals; D004553:Electric Conductivity; D005110:Extracellular Space / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology*; D011522:Protons; D011896:Rana temporaria; D011984:Sensory Receptor Cells / Q000502:physiology*; D013649:Taste / Q000502:physiology*