Graded expression of Semaphorin-1a cell-autonomously directs dendritic targeting of olfactory projection neurons
Graded expression of Semaphorin-1a cell-autonomously directs dendritic targeting of olfactory projection neurons
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DOI：
10.1016/j.cell.2006.12.028
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发表时间：
2007-01-26
期刊：
影响因子：
64.5
通讯作者：
Luo, Liqun
中科院分区：
文献类型：
--
作者：
Komiyama, Takaki;Sweeney, Lora B.;Luo, Liqun
轴突引导分子的梯度指导连续神经地图的形成，如脊椎动物视觉系统中的视网膜地图。在这里，我们展示了分子梯度也可以指导离散神经映射的形成。在苍蝇嗅觉系统中，50类嗅觉感受器神经元(ON)的轴突和50类投射神经元(PN)的树突在称为小球的离散单位上形成一对一的联系。我们提供了表达、功能丧失和功能获得的数据，以证明跨膜信号素-1a(SEMA-1a)的水平，作为受体或受体复合体的一部分，自主地作用于细胞，沿着触角叶腹内侧轴的背外侧引导三叉神经肽的树突状靶向。SEMA-1a还调节高级嗅觉中枢的PN轴突靶向。因此，Sema-1a的分级表达有助于从Ons到PNS再到高级大脑中枢的连接特异性，确保嗅觉信息在大脑中的正确表达。
Gradients of axon guidance molecules instruct the formation of continuous neural maps, such as the retinotopic map in the vertebrate visual system. Here we show that molecular gradients can also instruct the formation of a discrete neural map. In the fly olfactory system, axons of 50 classes of olfactory receptor neurons (ORNs) and dendrites of 50 classes of projection neurons (PNs) form one-to-one connections at discrete units called glomeruli. We provide expression, loss- and gain-of-function data to demonstrate that the levels of transmembrane Semaphorin-la (Sema-la), acting cell-autonomously as a receptor or part of a receptor complex, direct the dendritic targeting of PNs along the dorsolateral to ventromedial axis of the antennal lobe. Sema-1a also regulates PN axon targeting in higher olfactory centers. Thus, graded expression of Sema-1a contributes to connection specificity from ORNs to PNs and then to higher brain centers, ensuring proper representation of olfactory information in the brain.