Lateral motor column axons execute a ternary trajectory choice between limb and body tissues.
Lateral motor column axons execute a ternary trajectory choice between limb and body tissues.
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DOI：
10.1186/1749-8104-2-13
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发表时间：
2007-07-02
影响因子：
3.6
通讯作者：
Laufer, Ed
中科院分区：
文献类型：
--
作者：
Luria, Victor;Laufer, Ed
神经元地形图的形成需要在靶神经支配之前在中间选择点处适当地选择轴突轨迹。脊髓外侧运动柱(LMC)神经元的轴突被认为是专门支配肢体靶组织的，由转录因子密码定义。内侧和外侧LMC分支的轴突似乎在肢体底部执行二元决定，当它们在腹侧和背侧肢体轨迹之间进行选择时。引导运动轴突轨迹选择进入非肢体组织(如腹侧)的细胞逻辑仍不清楚。我们确定了支配后肢水平腹侧组织的运动神经的脊髓运动柱起源。我们意外地发现，LMC内侧轴突的一部分在后肢水平支配腹侧非肢体间充质，而不是进入腹侧肢体间充质。我们还发现，在一个条件BmprIa突变体中，所有腹侧后肢间充质都被转换为背侧身份，所有内侧LMC轴突被重定向到腹侧，而外侧LMC轴突支配双背肢。我们发现内侧LMC神经元同时支配腹侧和肢体靶点。虽然正常情况下只有内侧LMC轴突的一部分支配侧翼，但所有的轴突都有这样的能力。此外，LMC轴突在肢体底部执行腹侧、腹侧和背侧三种轨迹的选择。在做出这一选择时，内侧和外侧LMC轴突对这三种轨迹表现出不同的和不对称的相对偏好。这些数据将LMC重新定义为支配肢体和身体组织的运动柱。
Neuronal topographic map formation requires appropriate selection of axonal trajectories at intermediate choice points prior to target innervation. Axons of neurons in the spinal cord lateral motor column (LMC), as defined by a transcription factor code, are thought to innervate limb target tissues exclusively. Axons of the medial and lateral LMC divisions appear to execute a binary decision at the base of the limb as they choose between ventral and dorsal limb trajectories. The cellular logic that guides motor axon trajectory choices into non-limb tissues such as the ventral flank remains unclear. We determined the spinal cord motor column origin of motor nerves that innervate ventral flank tissues at hindlimb level. We found unexpectedly that a subset of medial LMC axons innervates ventral non-limb mesenchyme at hindlimb level, rather than entering ventral limb mesenchyme. We also found that in a conditional BmprIa mutant where all ventral hindlimb mesenchyme is converted to a dorsal identity, all medial LMC axons are redirected into the ventral flank, while lateral LMC axons innervate the bidorsal limb. We have found that medial LMC neurons innervate both ventral flank and limb targets. While normally only a subset of medial LMC axons innervate the flank, all are capable of doing so. Furthermore, LMC axons execute a ternary, rather than binary, choice at the base of the limb between ventral flank, ventral limb and dorsal limb trajectories. When making this choice, medial and lateral LMC axons exhibit different and asymmetric relative preferences for these three trajectories. These data redefine the LMC as a motor column that innervates both limb and body tissues.
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影响因子：
2.7
作者：
Eberhart, J;Swartz, ME;Krull, CD
通讯作者：
Krull, CD
影响因子：
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deLapeyrière, O
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Niswander, L
影响因子：
64.5
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通讯作者：
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