Polarized secretory trafficking directs cargo for asymmetric dendrite growth and morphogenesis
Polarized secretory trafficking directs cargo for asymmetric dendrite growth and morphogenesis
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DOI：
10.1016/j.neuron.2005.11.005
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发表时间：
2005-12-08
期刊：
影响因子：
16.2
通讯作者：
Ehlers, MD
中科院分区：
文献类型：
--
作者：
Horton, AC;Rácz, B;Ehlers, MD
树突的正常生长对神经元回路的形成至关重要，但是指导膜成分的添加以产生树突结构的细胞机制仍然不清楚。在这里，我们表明，后高尔基膜贩运是极化向较长的树突海马锥体神经元在体外和对顶端树突在体内。小高尔基前哨分区选择性地进入较长的树突，并排除轴突。在树突中，高尔基体前哨集中在分支点，在那里它们参与高尔基体后的运输。在细胞体内，高尔基体朝向最长的树突，这种高尔基体极性先于不对称的树突生长。选择性阻断后高尔基体运输的操作停止发育中的神经元中的树突生长，并导致成熟的锥体神经元中的树突收缩。此外，破坏高尔基体极性产生的神经元与对称的树突乔木缺乏一个单一的最长的主树突。这些结果定义了一种新的极化组织的神经元分泌贩运和定向膜贩运和不对称树突生长之间的机械联系。
Proper growth of dendrites is critical to the formation of neuronal circuits, but the cellular machinery that directs the addition of membrane components to generate dendritic architecture remains obscure. Here, we demonstrate that post-Golgi membrane trafficking is polarized toward longer dendrites of hippocampal pyramidal neurons in vitro and toward apical dendrites in vivo. Small Golgi outposts partition selectively into longer dendrites and are excluded from axons. In dendrites, Golgi outposts concentrate at branchpoints where they engage in post-Golgi trafficking. Within the cell body, the Golgi apparatus orients toward the longest dendrite, and this Golgi polarity precedes asymmetric dendrite growth. Manipulations that selectively block post-Golgi trafficking halt dendrite growth in developing neurons and cause a shrinkage of dendrites in mature pyramidal neurons. Further, disruption of Golgi polarity produces neurons with symmetric dendritic arbors lacking a single longest principal dendrite. These results define a novel polarized organization of neuronal secretory trafficking and demonstrate a mechanistic link between directed membrane trafficking and asymmetric dendrite growth.