Imaging Molecules and Circuits in Peripheral Taste Pathways

描述（由申请人提供）：我们开发了一种创新的方法来记录味觉传入神经元中的味觉诱发活动，具有良好的细胞和时间分辨率。该方法使用共聚焦功能性钙成像和在感觉神经元中表达GCaMP 3的转基因小鼠。通过仔细暴露膝状神经节在生活中，麻醉GCaMP 3-小鼠和应用味觉刺激口腔，我们现在可以记录强大的和可靠的反应，以辨别背后的味觉诱发信号的传输原则从味蕾到后脑。这些数据将大大扩展鼓索和岩浅大神经或膝状体神经节细胞的单单位电记录。我们能够同时记录大量的神经元。我们还设计了一个强大的策略，将单个膝状体神经节神经元的功能反应谱与其基因表达模式联系起来，并为不同功能类别的神经元建立强大的分子标记。 在两个完善的实验室的共同努力下，我们现在提出了一个多PI项目来开发这种新型制剂，并回答有关味道的关键问题。我们的新方法将极大地扩展我们对味觉外周感觉加工的认识。我们的初步数据证明了所有4个紧密关注的具体目标的可行性：目标1：味觉感觉传入细胞如何对甜，咸，苦，酸，鲜味和脂肪作出反应？目的2：味觉刺激的混合物是否增强味觉感觉传入神经元的反应？目的3：表达某些递质受体的神经节神经元是否支配特定的味觉细胞？目标4：是否有专门的神经元检测每一种味觉刺激，如果是这样，可以确定特定的分子标记物，与味觉传入神经元的反应，每一种口味的质量？

DESCRIPTION (provided by applicant): We have developed an innovative method to record taste-evoked activity in gustatory afferent neurons with good cellular and temporal resolution. The method uses confocal functional calcium imaging and transgenic mice that express GCaMP3 in sensory neurons. By carefully exposing geniculate ganglia in living, anesthetized GCaMP3-mice and applying taste stimuli to the oral cavity, we can now record robust and reliable responses to discern the principles behind the transmission of gustatory evoked signals from taste buds to the hindbrain. These data will considerably extend single unit electrical recordings from the chorda tympani and greater superficial petrosal nerves or from geniculate ganglion cells. We are able to recording simultaneously from large ensembles of neurons. We have also designed a powerful strategy to relate the functional response profiles of individual geniculate ganglion neurons to their patterns of gene expression and establish robust molecular markers for separate functional classes of neurons. In a concerted effort from two well-established laboratories, we now propose a multi-PI project to exploit this novel preparation and to answer key questions regarding taste. Our new approach will tremendously expand our knowledge of peripheral sensory processing in taste. Our preliminary data demonstrate the feasibility of all 4 tightly-focused Specific Aims: Aim 1: How do gustatory sensory afferent cells respond to sweet, salty, bitter, sour, umami tastes and fats? Aim 2: Do mixtures of taste stimuli enhance responses from gustatory sensory afferent neurons? Aim 3: Do ganglion neurons that express certain transmitter receptors innervate specific taste cells? Aim 4: Are there dedicated neurons that detect each taste stimulus, and if so, can specific molecular markers be identified that associate with gustatory afferent neuron responses for each taste quality?