Mapping gustatory neuron types.

项目总结 支配味蕾的传入感觉神经元在分子上还没有得到定义。 直到最近的水平。具体地说，目前还不清楚是否有不同类别的神经元 支配味蕾中成熟的感受器细胞类型。它也一直不清楚 是否有连接外周感受器细胞的专用神经回路，传入 脑干孤束核中的感觉神经元和第一中继神经元。 由于缺乏区分味觉神经元的分子标记，进展受到阻碍 单元类型。我们最近完成了膝状神经节单细胞RNA序列的研究 神经元。我们详细的生物信息学分析是公开的，揭示了神经元 基于其转录组图谱中的深度分离的亚型。我们的研究也得出了 允许我们区分味觉神经元类别的标记。我们建议 通过几种方式检查三个主要类别：T1、T2和T3。我们将评估每个人是否 一类神经元与特定感受野中的味蕾有关，或与特定味蕾有关 细胞类型。我们还将检查每一类神经元的中央投射以获得洞察力 它们在味觉中的潜在作用。第二，我们将评估味觉神经元 类型优先传达关于特定口味品质的信息。最后，我们将检查 我们最近发现的新型混合味觉-机械感觉神经元型的意义 报道称，在表达钙离子指示剂的转基因小鼠中，使用体内共聚焦钙离子成像， GCaMP。总而言之，这些分析将是第一次评估 味觉亚型的外周和中枢连通性及功能特性 神经元。

PROJECT SUMMARY The afferent sensory neurons that innervate taste buds have eluded definition at the molecular level until very recently. Specifically, it has been unclear if separate classes of neurons innervate the well-established receptor cell types in the taste bud. It has also been unclear whether there are dedicated neuronal circuits that connect peripheral receptor cells, afferent sensory neurons and the first relay neurons in the Nucleus of the Solitary Tract in the brainstem. Progress has been impeded by the lack of molecular markers to distinguish gustatory neuronal cell types. We have recently completed a study on single-cell RNAseq of geniculate ganglion neurons. Our detailed bioinformatics analyses, which are publicly accessible, revealed neuronal subtypes based on deep separations in their transcriptome profiles. Our study also yielded markers which permit us to distinguish the classes of gustatory neurons. We propose to examine the three main classes, T1, T2 and T3, in several ways. We will assess whether each class of neurons associates with taste buds in a given receptive field, or with particular taste bud cells types. We will also examine the central projections of neurons of each class for insights into their potential roles in gustation. Second, we will evaluate whether the gustatory neuron types preferentially convey information on particular taste qualities. And finally, we will examine the significance of the novel hybrid gustatory-mechanosensory neuron type that we recently reported, using in vivo confocal Ca2+ imaging in transgenic mice expressing the Ca2+ indicator, GCaMP. Together, these analyses will be the first to assess the extent of heterogeneity in the peripheral and central connectivity and functional properties of defined subtypes of gustatory neurons.