PHYSICOCHEMICAL INVESTIGATION OF TASTE

描述（改编自研究者摘要）： 酸度（pH值）的内部流体在一个狭窄的范围内是必不可少的所有 动物 味觉系统起着防止过量摄入的作用 食物和饮料中的酸，胃酸过多引起强烈的酸味 味，是一种天然的味道。 味觉感受器 细胞响应酸（酸味转导）将使用味觉研究 从啮齿类动物中分离出的味蕾和味觉细胞。 初步实验 表明细胞外pH值的变化（酸刺激）反映在 细胞内pH值成比例的变化，表明pH传感是一种 胞内突 此外，细胞内钙水平的变化 改变内部pH值，表明钙可能参与 酸敏感转导途径。 这一假设将使用pH值进行检验- 和钙敏感的荧光染料，以跟踪酸诱导的变化， 细胞内pH和细胞内钙的可能的后续变化。 将评估酸刺激期间膜电导的变化 使用膜片钳记录从分离的味觉细胞，以帮助建立 预测的质子运输途径的性质。 免费实验 将涉及允许记录鼓索味道的制剂 神经纤维，同时电压钳位受体上皮。 这个强大 技术将有助于确定是否酸敏感部分的 细胞是顶侧或基底侧的。 铵盐的味觉反应 共享酸传感系统的许多特性，并将进行检查 在一个单独的系列实验中使用类似的技术。 结果 这些研究将为酸（酸）味的接受提供新的见解， 它在pH平衡中起着重要作用。

DESCRIPTION (Adapted from the Investigator's Abstract): Regulation of the acidity (pH) of internal fluids within a narrow range is essential for all animals. The taste system plays a role in guarding against excessive intake of acid in foods and beverages with hyperacidity evoking an intense sour taste than is innately aversive. The mechanisms by which taste receptor cells respond to acid (sour taste transduction) will be studied using taste buds and taste cells isolated from rodents. Preliminary experiments indicate that changes in extracellular pH (acid stimulation) are mirrored by proportionate changes in intracellular pH, suggesting that pH-sensing is an intracellular process. In addition, changes in intracellular calcium levels alter internal pH, indicating that calcium may be involved in the acid-sensing transduction pathway. This hypothesis will be tested using pH- and calcium-sensitive fluorescent dyes to follow acid induced changes in intracellular pH and possible subsequent changes in intracellular calcium. Changes in membrane conductance during acid stimulation will be assessed using patch-clamp recording from isolated taste cells to help establish the nature of the predicted proton transport pathway. Complimentary experiments will involve a preparation which permits recording from chorda tympani taste nerve fibers while voltage-clamping the receptor epithelium. This powerful technique will be useful in determining whether the acid-sensing portions of the cells are apical or basolateral. Taste responses to ammonium salts share many of the properties of the acid sensing system and will be examined in a separate series of experiments using similar techniques. The results of these studies will provide new insights into sour (acid) taste reception, which plays an important role in pH balance.