While psychophysical and neurophysiological assessments of taste sensitivity to single chemical compounds have revealed some fundamental properties of gustatory processing, taste stimuli are rarely ingested in isolation. Arguably, the gustatory system was adapted to identify and report the presence of numerous chemicals ingested concurrently. To begin systematically exploring the detectability of a target stimulus in a background in rodents, we used a gustometer to train rats in a 2-response operant task to detect either NaCl (n = 8) or sucrose (n = 8) dissolved in water, and then tested the sensitivity of rats to the trained NaCl stimulus dissolved in a sucrose masker (0.3, 0.6, or 1.0 M, tested consecutively) versus sucrose, or the trained sucrose stimulus dissolved in a NaCl masker (0.04, 0.2, or 0.4 M) versus NaCl. Detection thresholds (EC₅₀ values) were determined for the target stimulus dissolved in each concentration of the masker. Except for 0.04 M NaCl, all masker concentrations tested increased the target stimulus EC₅₀. Target stimulus detectability decreased systematically as masker concentrations increased. The shift in liminal sensitivity for either target was similar when the threshold for the masker was considered. At least for these prototypical stimuli, it appears that the attenuating impact of a masker on the detection of a target stimulus depends on sensitivity to the masking stimulus. Further study will be required to generalize these results and extend them to more complex maskers, and to discern neural circuits involved in the detection of specific taste signals in the context of noisy backgrounds.

中文翻译：

---

掩盖了大鼠味觉刺激的检测：NaCl和蔗糖。

尽管对单个化合物的味觉敏感性的心理和神经生理学评估揭示了味觉加工的一些基本特性，但很少单独摄取味觉刺激。可以说，味觉系统适用于识别和报告同时摄入的多种化学物质的存在。为了开始系统地探索啮齿类动物在背景中的目标刺激的可检测性，我们使用了气压计训练大鼠进行2响应操作任务，以检测NaCl（n = 8）或蔗糖（n= 8）溶于水，然后测试大鼠对溶解于蔗糖掩蔽剂（0.3、0.6或1.0 M，连续测试）中的经过训练的NaCl刺激与蔗糖或溶解于NaCl掩蔽剂中的受训练的蔗糖刺激（ 0.04、0.2或0.4 M）相对于NaCl。确定溶解在每种掩蔽剂浓度中的目标刺激的检测阈值（EC ₅₀值）。除0.04 M NaCl外，所有测试的掩蔽剂浓度均增加了目标刺激EC ₅₀。随着掩蔽剂浓度的增加，目标刺激的可检测性逐渐降低。当考虑掩蔽物的阈值时，任一目标的门限灵敏度变化相似。至少对于这些原型刺激，似乎掩蔽剂对目标刺激的检测的衰减影响取决于对掩蔽刺激的敏感性。将需要进一步研究以概括这些结果，并将其扩展到更复杂的掩盖器，并辨别在嘈杂背景下检测特定味觉信号所涉及的神经回路。