ELECTROPHYSIOLOGY OF TASTE TRANSDUCTION

味觉传导的电生理学

• 批准号: 2125983
• 负责人: Sue C. Kinnamon
• 金额: $ 18.45万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2125983
• 关键词: G protein; Urodela; alternatives to animals in research; apical membrane; cell type; chemoreceptors; electron microscopy; electrophysiology; fresh water environment; membrane channels; membrane permeability; potassium channel; second messengers; stimulus /response; taste; voltage /patch clamp; G protein; Urodela; alternatives to animals in research; apical membrane; cell type; chemoreceptors; electron microscopy; electrophysiology; fresh water environment; membrane channels; membrane permeability; potassium channel; second messengers; stimulus /response; taste; voltage /patch clamp

The long-term goal of this project is to determine the cellular mechanisms involved in the detection and discrimination of taste stimuli by receptor cells. Using various configurations of the patch-clamp recording technique and electron microscopy combined with electrophysiological recording, the following specific aims will be addressed: 1. TO CHARACTERIZE THE EFFECT OF DIFFERENT TASTE STIMULI ON WHOLE-CELL CONDUCTANCES. The cellular mechanisms used by taste cells to detect bitter compounds, amino acids, glutathione and various salts will be determined by using giga-seal whole-cell recording. For each tastant it will be determined if ionic conductance changes are involved, if taste stimuli activate or modulate the conductance and if the effects of taste stimuli are direct, or involve G proteins and 2nd messengers. 2. TO DETERMINE THE SUBCELLULAR LOCALIZATION OF RECEPTORS AND CHANNELS INVOLVED IN TASTE TRANSDUCTION. Diverse types of proteins can serve receptive functions in taste cells, such as the voltage-sensitive K+ channels which we have shown to be restricted to the apical membrane. Are other types of taste "receptors" similarly restricted to the apical membrane of the taste cells? Loose-patch and whole-cell recording techniques will be used to map the distribution of (1) ligand-gated channels with receptors for taste stimuli, (2) taste receptors coupled to second messenger transduction mechanisms and (3) other channels involved in taste transduction. 3. TO CHARACTERIZE THE EFFECT OF DIFFERENT TASTE STIMULI ON SINGLE CHANNELS. The cellular mechanisms used by taste cells to detect taste stimuli will be characterized further using single-channel recording techniques to determine (1) the specific ion channels that are activated or modulated during taste transduction and (2) the role of G proteins and 2nd messengers. Together with Specific Aim #1, these experiments will establish the mechanism of transduction for different taste modalities.l 4. TO DETERMINE IF TASTE DISCRIMINATION OCCURS AT THE LEVEL OF THE RECEPTOR CELL. Taste cells will be studied with electron microscopy following whole-cell recording to determine (1) if the differences in membrane properties observed in taste cells can be attributed to morphologically-identifiable criteria, such as taste cell type, and (2) if specific cell types respond differentially to taste stimuli. Taken together, these studies will establish the whole-cell response to different categories of taste stimuli, the mechanisms of these responses, and the identity and localization of the receptors and channels involved. Additionally, these studies will determine whether taste discrimination involves distinct types of taste cells responding differentially to taste stimuli. Such information will not only enhance understanding of chemosensory transduction, but also provide clues to basic mechanisms involved in signal transduction.

该项目的长期目标是确定细胞机制 参与受体对味觉刺激的检测和区分 细胞。 使用Patch-Clamp记录技术的各种配置 和电子显微镜结合电生理记录， 以下特定目标将被解决： 1。表征不同味道刺激对全细胞的影响 电导。 味道细胞用于检测苦的细胞机制 化合物，氨基酸，谷胱甘肽和各种盐将由 使用Giga-Seal全细胞录制。 对于每个味道素 确定离子电导是否涉及变化，如果口味刺激 激活或调节电导以及味觉刺激的影响 是直接的，或涉及G蛋白和第二信使。 2。确定受体和通道的亚细胞定位 参与味觉转导。 多种类型的蛋白质可以服务 在味觉细胞中的接受功能，例如电压敏感的K+ 我们已证明仅限于顶膜的通道。 是 其他类型的味道“受体”类似地限制在顶端 味道细胞的膜？ 松散的点和全细胞记录 技术将用于绘制（1）配体门控的分布 带有味觉刺激受体的通道，（2）味道受体耦合到 第二信使转导机制和（3）涉及的其他渠道 口味转导。 3。表征不同味道刺激对单个的影响 频道。 味道细胞用于检测味道的细胞机制 刺激将使用单通道记录进一步表征 确定（1）激活或 在味道转导期间调节，（2）G蛋白和第二 使者。 与特定的目标＃1一起，这些实验将 建立不同味道模态转导的机制。L 4。确定味觉歧视是否发生在 受体细胞。 将使用电子显微镜研究味道细胞 按照全细胞记录，以确定（1）如果差异 在味觉细胞中观察到的膜特性可以归因于 形态学上可识别的标准，例如味道细胞类型，（2） 特定的细胞类型对味觉刺激的反应差异。 综上所述，这些研究将确定对 不同类别的口味刺激，这些反应的机制， 以及所涉及的受体和渠道的身份和定位。 此外，这些研究将确定味觉歧视 涉及不同类型的味觉细胞对味道的反应 刺激。 这些信息不仅会增强对 化学感应转导，但也为基本机制提供了线索 参与信号转导。