Scanning Blockface EM of Murine and Human Taste Buds

 描述(申请人提供)：味蕾是复杂的多细胞内脏，对味觉的检测是必不可少的。味蕾的细胞区分营养和潜在的有毒物质，并将这一信息传递给支配它们的味觉神经。尽管最近在理解味觉转导的分子信号转导方面取得了进展，但对细胞-细胞相互作用和信息向外周神经系统的传递缺乏完整的了解。我们建议使用一种新发明的技术--连续区块脸扫描EM--从小鼠和人类身上生成味蕾结构的完整3D图像，以测试味觉信息是否沿着专门针对个体味觉质量的专用“标记线”传输，或者大脑是否从味蕾接收到更复杂的信号。新的EM技术将允许对味蕾连接体进行详细的3D重建，从而可以分析关键特征，包括：1)单个神经纤维是否与一个味蕾中的多种细胞类型进行功能性接触，以及2)胶质样I型细胞是否完全分离其他类型的细胞，或者编码不同味觉品质的受体细胞之间是否存在功能相互作用的可能性。对味蕾详细结构的进一步了解将有助于研究人员就不同细胞元素之间的功能相互作用制定基于数据的假说，并更清楚地了解味蕾如何将味觉信息传递到大脑。 相关性：味蕾是复杂的感官内脏，对营养物质和毒素的检测至关重要。虽然在过去的十年里，味觉的许多分子机制已经被阐明，但我们仍然不清楚味蕾中不同细胞之间的功能组织和相互关系。这项提案中的研究将依靠新技术--连续区块面EM--来生成详细的味蕾三维图像，以解决味蕾向大脑传递味觉信息过程中的神经连接和细胞-细胞相互作用问题。

 DESCRIPTION (provided by applicant): Taste buds are complex multicellular endorgans essential for detection of taste. The cells of a taste bud distinguish between the nutritious and the potentially toxic, and communicate this information to the taste nerves innervating them. Despite recent advances in understanding the molecular signaling underlying taste transduction, a complete understanding of cell-cell interactions and transmission of information to the peripheral nervous system is lacking. We propose to use a newly invented technology, serial blockface scanning EM, to generate a complete 3D picture of taste bud structure from both mice and humans in order to test whether taste information is transmitted along dedicated "labeled lines" dedicated to an individual taste quality, or whether the brain receives a more complex signal from the taste buds. The novel EM technology will permit detailed 3D reconstruction of the taste bud connectome allowing for analysis of key features including: 1) whether individual nerve fibers make functional contact with more than one cell type in a bud, and 2) whether the glial-like Type I cells fully separate the other cell types or whether there is potential for functonal interactions between receptor cells encoding the different taste qualities. This greater understanding of the detailed structure of taste buds will help investigators formulate data-based hypotheses regarding functional interactions between the different cellular elements and a more clear understanding of how taste information is transmitted from taste buds to brain. RELEVANCE: Taste buds are complex sensory endorgans crucial for detection of both nutrients and toxins. While many of the molecular mechanisms underlying taste have been elucidated during the last decade, we still do not understand the functional organization and interrelationships between the diverse cells of a taste bud. Investigations in this proposal will rely on new technology, serial blockface EM, to generate detailed 3- dimensional images of taste buds to resolve questions about neural connectivity and cell-cell interactions in transmission of taste information from taste bud to brain.