Department of Biology and Howard Hughes Medical Institute, Stanford University, Stanford, United States.
Department of Bioengineering, Stanford University, Stanford, United States.
Elife. 2019 Oct 24;8:e49424. doi: 10.7554/eLife.49424.
Serotonin neurons of the dorsal and median raphe nuclei (DR, MR) collectively innervate the entire forebrain and midbrain, modulating diverse physiology and behavior. To gain a fundamental understanding of their molecular heterogeneity, we used plate-based single-cell RNA-sequencing to generate a comprehensive dataset comprising eleven transcriptomically distinct serotonin neuron clusters. Systematic in situ hybridization mapped specific clusters to the principal DR, caudal DR, or MR. These transcriptomic clusters differentially express a rich repertoire of neuropeptides, receptors, ion channels, and transcription factors. We generated novel intersectional viral-genetic tools to access specific subpopulations. Whole-brain axonal projection mapping revealed that DR serotonin neurons co-expressing vesicular glutamate transporter-3 preferentially innervate the cortex, whereas those co-expressing thyrotropin-releasing hormone innervate subcortical regions in particular the hypothalamus. Reconstruction of 50 individual DR serotonin neurons revealed diverse and segregated axonal projection patterns at the single-cell level. Together, these results provide a molecular foundation of the heterogenous serotonin neuronal phenotypes.
中缝背核和中缝核（DR、MR）的 5-羟色胺神经元共同支配整个前脑和中脑，调节多种生理和行为。为了深入了解它们的分子异质性，我们使用基于平板的单细胞 RNA 测序生成了一个包含 11 个转录上不同的 5-羟色胺神经元簇的综合数据集。系统的原位杂交将特定的簇映射到主要的 DR、尾侧 DR 或 MR。这些转录组簇差异表达丰富的神经肽、受体、离子通道和转录因子。我们生成了新的交又病毒遗传工具来访问特定的亚群。全脑轴突投射图谱显示，共表达囊泡谷氨酸转运体 3 的 DR 5-羟色胺神经元优先支配皮质，而共表达促甲状腺激素释放激素的神经元则特别支配皮质下区域，尤其是下丘脑。50 个单个 DR 5-羟色胺神经元的重建揭示了单细胞水平上的不同和分离的轴突投射模式。总的来说，这些结果为异质的 5-羟色胺神经元表型提供了分子基础。
