Intrinsic properties guide proximal abducens and oculomotor nerve outgrowth in avian embryos.
Intrinsic properties guide proximal abducens and oculomotor nerve outgrowth in avian embryos.
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内在特性指导禽类胚胎中近端外展神经和动眼神经的生长。
DOI：
10.1002/dneu.20948
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发表时间：
2012
影响因子：
3
通讯作者：
Sours,Emily
中科院分区：
文献类型：
--
作者：
Lance-Jones,Cynthia;Shah,Veeral;Noden,DrewM;Sours,Emily
脊椎动物眼睛的正确运动需要形成精确图案的轴突连接，将位于腹侧中脑和后脑特定位置的头体运动神经元与眼外肌连接起来。这项研究的目的是评估在禽类胚胎外展神经和动眼神经发育的早期阶段，内在的、群体特有的特性和外在的、特定于生长部位的线索的相对贡献。这是通过手术移位中脑和尾部后脑片段来完成的，这些片段已经通过电穿孔与EGFP构建物预先标记。移植物衍生的EGFP+动眼神经轴突进入后脑微环境，通常模仿外展神经的初始路径，并向颅侧走行。类似地，一些进入中脑微环境的EGFP+外展轴突模仿眼球运动的初始路径，并向腹侧运动。这些轴突中的许多(但不是全部)随后投射到它们通常不会神经支配的眼外肌。引人注目的是，EGFP+轴突的初始路径对于它们的新位置来说也是非典型的。当离开后脑位置时，大多数EGFP+动眼神经轴突实际上走到腹侧，并与宿主分支运动神经相连，这些神经与动眼神经具有共同的分子特征。类似地，当离开中脑位置时，一些EGFP+外展神经轴突转向尾部，平行于脑干延长，并接触到它们最初正确的目标--外直肌。这些数据揭示了动眼神经和外展神经群体特有的内在特性和共同的识别和响应外部定向线索的能力之间的相互作用。前者在最初的路径选择中起着突出的作用，而后者在随后的方向选择中似乎更具指导性。©2011 Wiley期刊，Inc.开发神经生物学72：167-185,2012
Proper movement of the vertebrate eye requires the formation of precisely patterned axonal connections linking cranial somatic motoneurons, located at defined positions in the ventral midbrain and hindbrain, with extraocular muscles. The aim of this research was to assess the relative contributions of intrinsic, population‐specific properties and extrinsic, outgrowth site‐specific cues during the early stages of abducens and oculomotor nerve development in avian embryos. This was accomplished by surgically transposing midbrain and caudal hindbrain segments, which had been pre‐labeled by electroporation with an EGFP construct. Graft‐derived EGFP+ oculomotor axons entering a hindbrain microenvironment often mimicked an abducens initial pathway and coursed cranially. Similarly, some EGFP+ abducens axons entering a midbrain microenvironment mimicked an oculomotor initial pathway and coursed ventrally. Many but not all of these axons subsequently projected to extraocular muscles that they would not normally innervate. Strikingly, EGFP+ axons also took initial paths atypical for their new location. Upon exiting from a hindbrain position, most EGFP+ oculomotor axons actually coursed ventrally and joined host branchiomotor nerves, whose neurons share molecular features with oculomotor neurons. Similarly, upon exiting from a midbrain position, some EGFP+ abducens axons turned caudally, elongated parallel to the brainstem, and contacted the lateral rectus muscle, their originally correct target. These data reveal an interplay between intrinsic properties that are unique to oculomotor and abducens populations and shared ability to recognize and respond to extrinsic directional cues. The former play a prominent role in initial pathway choices, whereas the latter appear more instructive during subsequent directional choices. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 72: 167–185, 2012