Bitter-Induced Salivary Proteins Increase Detection Threshold of Quinine, But Not Sucrose
Autor: | Laura E. Martin, Ann-Marie Torregrossa, Kristen Kay |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
0301 basic medicine
Male Saliva medicine.medical_specialty Sucrose Physiology Stimulus (physiology) 03 medical and health sciences Behavioral Neuroscience chemistry.chemical_compound 0302 clinical medicine Physiology (medical) Internal medicine Tannic acid medicine Animals Rats Long-Evans Salivary Proteins and Peptides Quinine Behavior Animal Original Articles Sensory Systems Rats 030104 developmental biology Endocrinology chemistry Taste Salivary Proteins Licking 030217 neurology & neurosurgery Sucrose octaacetate medicine.drug |
Zdroj: | Chem Senses |
Popis: | Exposures to dietary tannic acid (TA, 3%) and quinine (0.375%) upregulate partially overlapping sets of salivary proteins which are concurrent with changes in taste-driven behaviors, such as rate of feeding and brief access licking to quinine. In addition, the presence of salivary proteins reduces chorda tympani responding to quinine. Together these data suggest that salivary proteins play a role in bitter taste. We hypothesized that salivary proteins altered orosensory feedback to bitter by decreasing sensitivity to the stimulus. To that end, we used diet exposure to alter salivary proteins, then assessed an animal’s ability to detect quinine, using a 2-response operant task. Rats were asked to discriminate descending concentrations of quinine from water in a modified forced-choice paradigm, before and after exposure to diets that alter salivary protein expression in a similar way (0.375% quinine or 3% TA), or 1 of 2 control diets. Control animals received either a bitter diet that does not upregulate salivary proteins (4% sucrose octaacetate), or a nonbitter diet. The rats exposed to salivary protein-inducing diets significantly decreased their performance (had higher detection thresholds) after diet exposure, whereas rats in the control conditions did not alter performance after diet exposure. A fifth group of animals were trained to detect sucrose before and after they were maintained on the 3% TA diet. There was no significant difference in performance, suggesting that these shifts in threshold are stimulus specific rather than task specific. Taken together, these results suggest that salivary proteins reduce sensitivity to quinine. |
Databáze: | OpenAIRE |
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