Saliva and other taste stimuli are important for gustatory processing of linoleic acid.
Saliva and other taste stimuli are important for gustatory processing of linoleic acid.
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唾液和其他味觉刺激对于亚油酸的味觉加工很重要。
DOI：
10.1152/ajpregu.00217.2009
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Contreras,RobertJ
中科院分区：
文献类型：
--
作者：
Stratford,JenniferM;Contreras,RobertJ
矛盾的是，双侧鼓索神经 (CTX) 的横断提高了游离脂肪酸、亚油酸 (LA) 的味觉辨别阈值，但鼓索神经 (CT) 对单独舌下应用 LA 没有反应。 LA 可能需要唾液背景来激活味觉细胞，因为 CTX 通过颌下和舌下唾液腺的去神经来减少唾液分泌。为了评估唾液的作用，我们测量了颌下和舌下唾液腺被切除的动物的 LA 味觉辨别阈值，并记录了对人工唾液中混合的 LA 的 CT 反应。部分脱唾液将 LA 辨别阈值从 5.5 至 11 μM 之间转变为 11 至 22 μM 之间。然而，这种效果并不像之前在 CTX 动物身上看到的那么明显。令人惊讶的是，CT 对 LA 与人工唾液混合没有反应，这表明人工唾液可能缺乏 LA 味道所需的成分。此外，脂肪可能主要增强其他味道。我们之前报道过 LA 会增加 CT 对谷氨酸钠 (MSG) 的反应。因此，我们还记录了麻醉大鼠对 LA 和氯化钠 (NaCl)、蔗糖 (SUC)、柠檬酸 (CA) 或盐酸奎宁 (QHCl) 味觉混合物的 CT 全神经反应。我们发现 LA 增加了 CT 对 NaCl 的反应，但没有改变 CT 对 SUC、CA 和 QHCl 的反应。因此，CT 记录要么缺乏检测 SUC、CA 和 QHCl 微小变化的灵敏度，要么 LA 可能仅影响 CT 对 MSG 和 NaCl 的反应，也许是通过专门调节 Na+ 的味觉处理。
Paradoxically, bilateral transection of the chorda tympani nerve (CTX) raises the taste discrimination threshold for the free fatty acid, linoleic acid (LA), yet the chorda tympani nerve (CT) is unresponsive to lingual application of LA alone. LA may require a background of saliva to activate taste cells, since CTX decreases saliva production through denervation of the submaxillary and sublingual salivary glands. To assess the role of saliva, we measured LA taste discrimination thresholds for animals whose submaxillary and sublingual salivary glands were removed and also recorded CT responses to LA mixed in artificial saliva. Partial desalivation shifted LA discrimination thresholds from between 5.5 and 11 μM to between 11 and 22 μM. However, this effect was not as pronounced as previously seen with CTX animals. Surprisingly, the CT was unresponsive to LA mixed with artificial saliva, suggesting that artificial saliva may lack components necessary for LA taste. Additionally, fats may primarily enhance other tastes. We previously reported that LA increases CT responses to monosodium glutamate (MSG). Thus we also recorded CT whole nerve responses to taste mixtures of LA and sodium chloride (NaCl), sucrose (SUC), citric acid (CA), or quinine hydrochloride (QHCl) in anesthetized rats. We found that LA increased CT responses to NaCl but did not alter CT responses to SUC, CA, and QHCl. Thus CT recordings either lack the sensitivity to detect small changes to SUC, CA, and QHCl or LA may affect CT responses to MSG and NaCl only, perhaps by specifically modulating gustatory processing of Na+.