Differential axonal projection of mitral and tufted cells in the mouse main olfactory system
Differential axonal projection of mitral and tufted cells in the mouse main olfactory system
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DOI：
10.3389/fncir.2010.00120
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发表时间：
2010-09-23
影响因子：
3.5
通讯作者：
Chen, Wei R.
中科院分区：
文献类型：
--
作者：
Nagayama, Shin;Enerva, Allicia;Chen, Wei R.
在过去的十年中，关于嗅觉感觉神经元与嗅球（OB）肾小球轴突连接的功能组织已经得到了很多阐明。然而，OB 的投射神经元如何处理气味输入并将此信息发送到更高的大脑中枢的方式仍不清楚。在这里，我们报告使用双光子显微镜对 OB 神经元的轴突投影模式进行远程、大规模追踪。将示踪剂注射到单个肾小球中显示出在小鼠大脑的侧腹侧表面上广泛分布的二尖瓣/簇状细胞轴突投影，包括前/后梨状皮层（PC）和嗅结节（OT）。我们注意到两组不同的标记轴突：PC 定向轴突和 OT 定向轴突。每组都占据侧嗅道的不同部分。面向 PC 的轴突将轴突侧枝投射到 PC 的大片区域，但只有少数侧枝投射到 OT。 OT 定向轴突密集地将轴突侧枝主要投射到前外侧 OT (alOT)。将不同颜色的染料注射到 OB 外部丛状层的浅表和深层部分揭示了 PC 定向轴突群体起源于假定的二尖瓣细胞，而 OT 定向轴突起源于假定的簇状细胞。这些数据表明，尽管二尖瓣细胞和簇状细胞从共享的肾小球接收相似的气味信号，但它们以不同的方式处理气味信息，并通过 PC 和 alot 将其输出发送到不同的高级大脑中心。
In the past decade, much has been elucidated regarding the functional organization of the axonal connection of olfactory sensory neurons to olfactory bulb (OB) glomeruli. However, the manner in which projection neurons of the OB process odorant input and send this information to higher brain centers remains unclear. Here, we report long-range, large-scale tracing of the axonal projection patterns of OB neurons using two-photon microscopy. Tracer injection into a single glomerulus demonstrated widely distributed mitral/tufted cell axonal projections on the lateroventral surface of the mouse brain, including the anterior/posterior piriform cortex (PC) and olfactory tubercle (OT). We noted two distinct groups of labeled axons: PC-orienting axons and OT-orienting axons. Each group occupied distinct parts of the lateral olfactory tract. PC-orienting axons projected axon collaterals to a wide area of the PC but only a few collaterals to the OT. OT-orienting axons densely projected axon collaterals primarily to the anterolateral OT (alOT). Different colored dye injections into the superficial and deep portions of the OB external plexiform layer revealed that the PC-orienting axon populations originated in presumed mitral cells and the OT-orienting axons in presumed tufted cells. These data suggest that although mitral and tufted cells receive similar odor signals from a shared glomerulus, they process the odor information in different ways and send their output to different higher brain centers via the PC and alOT.