|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Oral Biology, Ohio State University, Columbus, Ohio, United States
* To whom correspondence should be addressed. E-mail: travers.3{at}osu.edu.
Molecular data suggest that receptors for all bitter ligands are coexpressed in the same taste receptor cells (TRCs) while physiological results indicate that individual TRCs respond only to a subset of bitter stimuli. It is also unclear to what extent bitter-responsive neurons are stimulated by non-bitter stimuli. To explore these issues, single neuron responses were recorded from the rat nucleus of the solitary tract (NST) during whole-mouth stimulation with a variety of bitter compounds: 10 µM cycloheximide, 7 mM propylthiouracil, 10mM denatonium benzoate, and 3mM quinine hydrochloride at intensities matched for behavioral effectiveness. Stimuli representing the remaining putative taste qualities were also tested. Particular emphasis was given to activating taste receptors in the foliate papillae innervated by the quinine-sensitive glossopharyngeal nerve. This method revealed a novel population of bitter-best (B-best) cells with foliate receptive fields and significant selectivity for bitter tastants. Across all neurons, multidimensional scaling depicted bitter stimuli as loosely clustered yet clearly distinct from non-bitter tastants. When neurons with posterior receptive fields were analyzed alone, bitter stimuli formed a tighter cluster. Nevertheless, responses to bitter stimuli were variable across B-best neurons, with cycloheximide the most, and quinine the least frequent optimal stimulus. These results indicate heterogeneity for the processing of ionic and non-ionic bitter tastants, which is dependent on receptive field. Further, they suggest that neurons selective for bitter substances could contribute to taste coding.
This article has been cited by other articles:
![]() |
M.-F. Wang, L. E. Marks, and M. E. Frank Taste Coding after Selective Inhibition by Chlorhexidine Chem Senses, October 1, 2009; 34(8): 653 - 666. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. H. Lemon and R. F. Margolskee Contribution of the T1r3 Taste Receptor to the Response Properties of Central Gustatory Neurons J Neurophysiol, May 1, 2009; 101(5): 2459 - 2471. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. C. Geran and S. P. Travers Bitter-Responsive Gustatory Neurons in the Rat Parabrachial Nucleus J Neurophysiol, March 1, 2009; 101(3): 1598 - 1612. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Nasse, D. Terman, S. Venugopal, G. Hermann, R. Rogers, and J. B. Travers Local circuit input to the medullary reticular formation from the rostral nucleus of the solitary tract Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2008; 295(5): R1391 - R1408. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. K. Cho and C.-S. Li Gustatory Neural Circuitry in the Hamster Brain Stem J Neurophysiol, August 1, 2008; 100(2): 1007 - 1019. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. R. Kinzeler and S. P. Travers Licking and gaping elicited by microstimulation of the nucleus of the solitary tract Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2008; 295(2): R436 - R448. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Grover and M. E. Frank Regional Specificity of Chlorhexidine Effects on Taste Perception Chem Senses, April 1, 2008; 33(4): 311 - 318. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Behrens, S. Foerster, F. Staehler, J.-D. Raguse, and W. Meyerhof Gustatory Expression Pattern of the Human TAS2R Bitter Receptor Gene Family Reveals a Heterogenous Population of Bitter Responsive Taste Receptor Cells J. Neurosci., November 14, 2007; 27(46): 12630 - 12640. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. D. Dotson and A. C. Spector Behavioral Discrimination between Sucrose and Other Natural Sweeteners in Mice: Implications for the Neural Coding of T1R Ligands J. Neurosci., October 17, 2007; 27(42): 11242 - 11253. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |