Neuron types in the zebrafish optic tectum labeled by an id2b transgene
Neuron types in the zebrafish optic tectum labeled by an id2b transgene
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DOI：
10.1002/cne.24815
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发表时间：
2019-11-26
影响因子：
2.5
通讯作者：
Robles, Estuardo
中科院分区：
文献类型：
--
作者：
DeMarco, Elisabeth;Xu, Nina;Robles, Estuardo
斑马鱼幼虫的视顶盖已成为理解神经回路如何控制视觉引导行为的重要模型。该领域的进一步进展将需要工具来监测和操纵具有细胞类型特异性的顶盖神经元。在这里，我们表征了 id2b:gal4 转基因标记的顶盖神经元的形态和神经递质表型。稳定转基因 id2b:gal4 幼虫的全脑成像揭示了视顶盖、小脑和后脑的一部分神经元的标记。 id2b:gal4 表达模式中单个神经元的遗传镶嵌标记使我们能够表征具有不同形态和连接性的三种顶盖神经元类型。第一种是先前在其他硬骨鱼视顶盖中发现的神经元类型：顶盖锥体神经元（PyrN）。 PyrN 是局部中间神经元，在顶盖神经毡中形成两个分层树突轴和一个分层轴突轴。由 id2b:gal4 转基因标记的第二种顶盖神经元类型是投影神经元，它在顶盖神经毡中形成分层树突乔木，以及离开顶盖以形成纵向环面 (TL) 的地形投影的轴突。标记的第三种神经元类型是具有非分层树突轴和到被盖的下降轴突投射的投射神经元。这些发现确立了 id2b:gal4 转基因作为未来研究的有用工具，旨在阐明顶盖、TL 和被盖在视觉引导行为中的功能作用。
The larval zebrafish optic tectum has emerged as a prominent model for understanding how neural circuits control visually guided behaviors. Further advances in this area will require tools to monitor and manipulate tectal neurons with cell type specificity. Here, we characterize the morphology and neurotransmitter phenotype of tectal neurons labeled by an id2b:gal4 transgene. Whole-brain imaging of stable transgenic id2b:gal4 larvae revealed labeling in a subset of neurons in optic tectum, cerebellum, and hindbrain. Genetic mosaic labeling of single neurons within the id2b:gal4 expression pattern enabled us to characterize three tectal neuron types with distinct morphologies and connectivities. The first is a neuron type previously identified in the optic tectum of other teleost fish: the tectal pyramidal neuron (PyrN). PyrNs are local interneurons that form two stratified dendritic arbors and one stratified axonal arbor in the tectal neuropil. The second tectal neuron type labeled by the id2b:gal4 transgene is a projection neuron that forms a stratified dendritic arbor in the tectal neuropil and an axon that exits tectum to form a topographic projection to torus longitudinalis (TL). A third neuron type labeled is a projection neuron with a nonstratified dendritic arbor and a descending axonal projection to tegmentum. These findings establish the id2b:gal4 transgenic as a useful tool for future studies aimed at elucidating the functional role of tectum, TL, and tegmentum in visually guided behaviors.