Neural Taste and Thermal Coding in Geniculate Ganglion

描述（申请人提供）：味觉是选择食物和摄入食物的关键感官系统。在目前的资助期内获得的结果提供了有趣的新发现，包括温度如何刺激特定类型的味觉神经元，钠剥夺如何增加盐摄入的显著性，以及对脂肪味道的行为反应。本研究的长期目标是：(1)外周味觉神经元的温度加工机制和行为研究中的味觉-温度相互作用；(2)醛固酮和体钠水平作为剥夺引起的盐味神经反应变化的介质的作用；(3)脂肪味觉的感官加工和脂肪对其他味觉刺激的调节。这些都是化学感觉研究领域中未解决的重要问题，从我们之前的工作中逻辑地遵循，并将通过为上述目的而明确开发的电生理和行为方法来解决。具体目的包括研究味觉和热刺激是否在特定类型的外周味觉神经元中具有加性效应，以及热刺激本身是否引起大鼠的味觉感觉。我们还将确定TRPM8通道是否是介导味觉神经元对冷却反应的机制。我们还建议研究短暂的饮食钠剥夺对味觉神经对盐刺激反应的影响，这种变化的机制，以及身体钠水平的补充是否能恢复味觉神经的反应性。最后，我们将探索味觉神经对脂肪单独和与其他味觉刺激结合的反应，并将开展研究来评估味觉神经对脂肪味觉检测和脂肪味觉介导行为的贡献。总体而言，该项目将使用单细胞和全神经记录来阐明外周味觉神经元中温度、盐和脂肪的信息处理，并使用行为方法来帮助解决这些重要刺激如何介导行为变化的谜团。

DESCRIPTION (provided by applicant): Taste is a critical sensory system for food selection and ingestion. Results obtained during the current funding period have provided intriguing new findings about how temperature is a stimulus for specific types of gustatory neurons, how sodium deprivation increase the salience of salt intake, and about behavioral responses to the taste of fat. The long-term objectives of this proposal are to investigate: (1) temperature- processing mechanisms in peripheral taste neurons and taste-temperature interaction in behavioral studies; (2) the role of aldosterone and body sodium levels as mediators for deprivation-induced changes in salt taste nerve responses; and (3) sensory processing of fat taste and the modulation of other taste stimuli by fat. These are significant unanswered questions in the field of chemosensory research that follow logically from our previous work and that will be addressed with electrophysiological and behavioral methodology developed explicitly for the purposes outlined above. The specific aims include investigating whether taste and thermal stimulation have additive effects in specific types of peripheral taste neurons and whether thermal stimulation itself elicits taste sensations in rats. We will also determine whether the TRPM8 channel is the mechanism that mediates responses to cooling in taste neurons. We also propose to investigate the effect of brief dietary sodium deprivation on taste nerve responsiveness to salt stimulation, the mechanism(s) that underlie such changes, and whether repletion of body sodium levels restores taste nerve responsiveness. Finally, we will explore taste nerve responses to fat alone and in combination with other taste stimuli, and will conduct studies to evaluate the contribution of gustatory nerves to the detection of fat taste and fat taste-mediated behaviors. Overall, this project will use single-cell and whole nerve recording to illuminate information processing of temperature, salt, and fat in peripheral taste neurons and behavioral methods to help solve the mystery of how these important stimuli mediate changes in behavior.