Multiple influences on the migration of precerebellar neurons in the caudal medulla.
Multiple influences on the migration of precerebellar neurons in the caudal medulla.
复制标题
对尾髓质小脑前神经元迁移的多重影响。
作者：
I. D. Diego;K. Kyriakopoulou;Domna Karagogeos;M. Wassef
注定形成几个小脑前核的神经元在后脑尾部的背侧神经上皮（菱形唇）中产生。它们形成两条腹向迁移流，其行为不同。而在浅层迁移的神经元迁移在软膜下的位置和跨越中线，以解决到对侧后脑，在橄榄迁移的神经元旅行更深的实质和停止同侧对底板。在本研究中，我们比较了两个神经元群体在器官型培养系统中的行为，该系统保留了其体内环境的几个方面。这两个迁移发生在小鼠后脑外植体解剖在E11.5，即使当底板被消融在文化时期的开始，表明他们可以依靠已经分布在神经管的背腹线索。然而，表面迁移所需的当地限制比橄榄迁移更具体。不同的化学吸引和化学反应信号被发现对迁移起作用。底板表现出强烈的化学吸引力的影响，这两个迁移，偏离其正常路径的异位底板碎片的方向。还发现它会产生短程停止信号并诱导劣质橄榄聚集。腹侧神经管也能抑制或减缓橄榄核神经元的迁移。有趣的是，虽然异位来源netrin被发现影响两个迁移，这种效果是局部调制和影响差异的连续阶段的迁移。与这一观察结果一致，而在浅表迁移的神经元表达Dcc-netrin受体，迁移的橄榄神经元不表达Dcc之前，他们到达中线。我们的观察提供了一个更清晰的图片层次的环境线索，影响这些小脑前核的形态发生。
Neurons destined to form several precerebellar nuclei are generated in the dorsal neuroepithelium (rhombic lip) of caudal hindbrain. They form two ventrally directed migratory streams, which behave differently. While neurons in the superficial migration migrate in a subpial position and cross the midline to settle into the contralateral hindbrain, neurons in the olivary migration travel deeper in the parenchyma and stop ipsilaterally against the floor plate. In the present study, we compared the behavior of the two neuronal populations in an organotypic culture system that preserves several aspects of their in vivo environment. Both migrations occurred in mouse hindbrain explants dissected at E11.5 even when the floor plate was ablated at the onset of the culture period, indicating that they could rely on dorsoventral cues already distributed in the neural tube. Nevertheless, the local constraints necessary for the superficial migration were more specific than for the olivary migration. Distinct chemoattractive and chemorespulsive signal were found to operate on the migrations. The floor plate exhibited a strong chemoattractive influence on both migrations, which deviated from their normal path in the direction of ectopic floor plate fragments. It was also found to produce a short-range stop signal and to induce inferior olive aggregation. The ventral neural tube was also found to inhibit or slow down the migration of olivary neurons. Interestingly, while ectopic sources of netrin were found to influence both migrations, this effect was locally modulated and affected differentially the successive phases of migration. Consistent with this observation, while neurons in the superficial migration expressed the Dcc-netrin receptor, the migrating olivary neurons did not express Dcc before they reached the midline. Our observations provide a clearer picture of the hierarchy of environmental cues that influence the morphogenesis of these precerebellar nuclei.
体外连合轴突的方向响应底板衍生的化学引诱剂。
DOI：
10.1242/dev.110.1.19
发表时间：
1990
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Placzek,M;Tessier-Lavigne,M;Jessell,T;Dodd,J
通讯作者：
Dodd,J
DOI：
10.1073/pnas.95.16.9602
发表时间：
1998-08-04
影响因子：
11.1
作者：
Waschek, JA;Casillas, RA;Rodriguez, WI
通讯作者：
Rodriguez, WI