Department of Oral Health and Diagnostic Sciences, Division of Periodontology, Center for Chemosensory Sciences, School of Dental Medicine, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-1715, USA.
Chem Senses. 2012 Sep;37(7):603-12. doi: 10.1093/chemse/bjs042. Epub 2012 Mar 26.
Component signaling in taste mixtures containing both beneficial and dangerous chemicals depends on peripheral processing. Unidirectional mixture suppression of chorda tympani (CT) nerve responses to sucrose by quinine and acid is documented for golden hamsters (Mesocricetus auratus). To investigate mixtures of NaCl and acids, we recorded multifiber responses to 50 mM NaCl, 1 and 3 mM citric acid and acetic acid, 250 μM citric acid, 20 mM acetic acid, and all binary combinations of each acid with NaCl (with and without 30 μM amiloride added). By blocking epithelial Na(+) channels, amiloride treatment separated amiloride-sensitive NaCl-specific responses from amiloride-insensitive electrolyte-generalist responses, which encompass all of the CT response to the acids as well as responses to NaCl. Like CT sucrose responses, the amiloride-sensitive NaCl responses were suppressed by as much as 50% by citric acid (P = 0.001). The amiloride-insensitive electrolyte-generalist responses to NaCl + acid mixtures approximated the sum of NaCl and acid component responses. Thus, although NaCl-specific responses to NaCl were weakened in NaCl-acid mixtures, electrolyte-generalist responses to acid and NaCl, which tastes KCl-like, were transmitted undiminished in intensity to the central nervous system. The 2 distinct CT pathways are consistent with known rodent behavioral discriminations.
味觉混合物中有益和有害化学物质的成分信号取决于外围处理。金黄仓鼠的鼓索神经（CT）对蔗糖的单向混合物抑制作用被奎宁和酸证实。为了研究 NaCl 和酸的混合物，我们记录了对 50mM NaCl、1 和 3mM 柠檬酸和乙酸、250μM 柠檬酸、20mM 乙酸以及每种酸与 NaCl 的所有二元组合（添加和不添加 30μM 阿米洛利）的多纤维反应。通过阻断上皮 Na(+)通道，阿米洛利处理将阿米洛利敏感的 NaCl 特异性反应与阿米洛利不敏感的电解质通用反应分离，后者包含了 CT 对所有酸以及对 NaCl 的反应。与 CT 蔗糖反应一样，柠檬酸对阿米洛利敏感的 NaCl 反应的抑制作用高达 50%（P=0.001）。阿米洛利不敏感的电解质通用反应对 NaCl+酸混合物的反应接近 NaCl 和酸成分反应的总和。因此，尽管 NaCl 对 NaCl 的特异性反应在 NaCl-酸混合物中减弱，但对酸和 NaCl（味道类似于 KCl）的电解质通用反应仍会强度不减地传递到中枢神经系统。这两个不同的 CT 途径与已知的啮齿动物行为辨别一致。
