Netrin 1 provides a chemoattractive cue for the ventral migration of GnRH neurons in the chick forebrain
Netrin 1 provides a chemoattractive cue for the ventral migration of GnRH neurons in the chick forebrain
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DOI：
10.1002/cne.22319
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发表时间：
2010-06
影响因子：
2.5
通讯作者：
S. Murakami;H. Ohki‐Hamazaki;Keisuke Watanabe;K. Ikenaka;K. Ono
中科院分区：
文献类型：
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作者：
S. Murakami;H. Ohki‐Hamazaki;Keisuke Watanabe;K. Ikenaka;K. Ono
下丘脑促性腺激素释放激素（GnRH）神经元起源于嗅觉基板，并在胚胎发育过程中迁移到前脑。我们发现 GnRH 神经元在雏鸡内侧端脑中以两种不同的模式迁移：它们最初经历与嗅觉纤维子集相关的嗜轴迁移，沿背尾方向。随后是腹侧定向切向迁移至基底前脑。由于许多向腹侧迁移的 GnRH 神经元并不遵循不同的纤维束，因此有人提出，可扩散的引导分子在该迁移过程中发挥了作用。长程扩散因子 netrin 1 在连合板下部和大脑皮层下隔膜中表达，但不沿着 GnRH 神经元的嗜轴迁移路径表达。 GnRH 神经元向腹侧定向迁移的失败及其向背内侧前脑的错误路由是由靠近连合板顶部的隔膜背尾部分中 netrin 1 的错误表达引起的，这是 GnRH 神经元迁移到腹侧方向的地方。在这种情况下，一部分嗅觉纤维也会延伸，但异常纤维和错误路线的 GnRH 神经元之间不存在紧密接触。共培养实验表明，netrin 1 对迁移 GnRH 神经元具有吸引力。这些结果提供证据表明，netrin 1 对隔膜背尾部分迁移的 GnRH 神经元起化学引诱作用，并有可能调节 GnRH 神经元向腹侧隔膜和视前区的腹侧迁移。 J.Comp。内罗尔。 518:2019–2034, 2010。© 2010 Wiley-Liss, Inc.
Hypothalamic gonadotropin‐releasing hormone (GnRH) neurons originate in the olfactory placode and migrate to the forebrain during embryonic development. We found that GnRH neurons migrated in two different modes in the chick medial telencephalon: they initially underwent axophilic migration in association with a subset of olfactory fibers in a dorsocaudal direction. This was followed by ventrally directed tangential migration to the basal forebrain. Since many of the ventrally migrating GnRH neurons did not follow distinct fiber fascicles, it is proposed that diffusible guidance molecules played a role in this migratory process. A long‐range diffusible factor, netrin 1, was expressed in the lower part of the commissural plate and the subpallial septum, but not along the axophilic migratory route of GnRH neurons. Failure of ventrally directed migration of GnRH neurons and their misrouting to the dorsomedial forebrain was induced by misexpression of netrin 1 in the dorsocaudal part of the septum near the top of the commissural plate, which is where the migration of GnRH neurons changed to a ventral direction. In such cases, a subset of olfactory fibers also extended, but close contact between aberrant fibers and misrouted GnRH neurons did not exist. A coculture experiment demonstrated that netrin 1 exerts an attractive effect on migrating GnRH neurons. These results provide evidence that netrin 1 acts as chemoattractant to migrating GnRH neurons at the dorsocaudal part of the septum and has the potential to regulate the ventral migration of GnRH neurons to the ventral septum and the preoptic area. J. Comp. Neurol. 518:2019–2034, 2010. © 2010 Wiley‐Liss, Inc.