PLCbeta2-independent behavioral avoidance of prototypical bitter-tasting ligands.
Using a brief-access taste assay, we show in the present report that although phospholipase C beta2 knockout (PLCbeta2 KO) mice are unresponsive to low- and midrange concentrations of quinine and denatonium, they do significantly avoid licking higher concentrations of these aversive compounds. PLCbeta2 KO mice displayed no concentration-dependent licking of the prototypical sweetener sucrose but were similar to wild-type mice in their responses to citric acid and NaCl, notwithstanding some interesting exceptions. Although these findings confirm an essential role for PLCbeta2 in taste responsiveness to sucrose and to low- to midrange concentrations of quinine and denatonium in mice as previously reported, they importantly suggest that higher concentrations of the latter two compounds, which are bitter to humans, can engage a PLCbeta2-independent taste transduction pathway.
Dotson
Cedrick D
CD
Department of Psychology, University of Florida, PO Box 112250, Gainesville, FL 32611-2250, USA.
Roper
Stephen D
SD
Spector
Alan C
AC
D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D008024:Ligands; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000502:physiology*; D054801:Phosphoinositide Phospholipase C; D000644:Quaternary Ammonium Compounds / Q000008:administration & dosage; D011803:Quinine / Q000008:administration & dosage; D012684:Sensory Thresholds; D015398:Signal Transduction; D013268:Stimulation, Chemical; D013395:Sucrose / Q000008:administration & dosage; D013649:Taste; D010738:Type C Phospholipases / Q000172:deficiency / Q000502:physiology*
D008024:Ligands; D009419:Nerve Tissue Proteins; D054801:Phosphoinositide Phospholipase C; D000644:Quaternary Ammonium Compounds; D011803:Quinine; D013395:Sucrose; D010738:Type C Phospholipases; C503884:Plch2 protein, mouse; C043414:denatonium