Taste receptor cells that discriminate between bitter stimuli.
Recent studies showing that single taste bud cells express multiple bitter taste receptors have reignited a long-standing controversy over whether single gustatory receptor cells respond selectively or broadly to tastants. We examined calcium responses of rat taste receptor cells in situ to a panel of bitter compounds to determine whether individual cells distinguish between bitter stimuli. Most bitter-responsive taste cells were activated by only one out of five compounds tested. In taste cells that responded to multiple stimuli, there were no significant associations between any two stimuli. Bitter sensation does not appear to occur through the activation of a homogeneous population of broadly tuned bitter-sensitive taste cells. Instead, different bitter stimuli may activate different subpopulations of bitter-sensitive taste cells.
Department of Physiology and Biophysics, Program in Neuroscience, University of Miami School of Medicine, 1600 NW 10th Avenue, Miami, FL 33136, USA. acaicedo@chroma.med.miami.edu
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D000818:Animals; D002118:Calcium / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D004192:Discrimination, Psychological; D066298:In Vitro Techniques; D018613:Microscopy, Confocal; D010670:Phenylthiourea / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology; D011803:Quinine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013395:Sucrose / Q000031:analogs & derivatives / Q000494:pharmacology; D013649:Taste / Q000502:physiology*; D013650:Taste Buds / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D013652:Taste Threshold
D000644:Quaternary Ammonium Compounds; C026879:sucrose octaacetate; C043414:denatonium; D013395:Sucrose; D010670:Phenylthiourea; D003513:Cycloheximide; D011803:Quinine; D002118:Calcium