Fritzsch B
Department of Biomedical Sciences, Creighton University, Omaha, Nebraska 68178, USA.
Ann N Y Acad Sci. 1996 Jun 19;781:21-33. doi: 10.1111/j.1749-6632.1996.tb15690.x.
The data presented here show that labyrinthine and facial branchiomotor efferent cells in the chicken and the mouse become postmitotic overlappingly, both spatially and temporally. Differential migration of labyrinthine efferents and facial motoneurons leads to the already described distinct distribution of labyrinthine efferents and facial motoneurons in adult brains. Differences exist between the chicken and the mouse with respect to the origin of labyrinthine efferents (rhombomere 4 and 5 for the chicken; rhombomere 4 alone for the mouse) and the way contralateral labyrinthine efferents form (migration across the floor plate in the chicken; extension of an axon across the floor plate in the mouse). The different routes taken by migrating motoneurons may all be mediated by substances released from the floor plate, some of which were recently characterized. Labyrinthine efferent axons and facial motoneuron axons segregate at distinctly different areas in the chicken and mouse: outside the brain in the former and inside the brain in the latter. Examination of the possible basis for pathway selection tends to support the idea that efferents use intact afferent fibers as highways for their navigation to distinct sensory epithelia.
此处呈现的数据表明，鸡和小鼠的迷路及面神经分支运动传出细胞在空间和时间上均重叠地进入有丝分裂后期。迷路传出神经元和面神经运动神经元的差异迁移导致成年大脑中迷路传出神经元和面神经运动神经元呈现出已描述的不同分布。鸡和小鼠在迷路传出神经元的起源（鸡为菱脑节4和5；小鼠仅为菱脑节4）以及对侧迷路传出神经元的形成方式（鸡中穿过底板迁移；小鼠中轴突延伸穿过底板）方面存在差异。迁移的运动神经元所采用的不同路径可能均由底板释放的物质介导，其中一些物质最近已得到表征。迷路传出轴突和面神经运动神经元轴突在鸡和小鼠中于截然不同的区域分离：在鸡中于脑外分离，在小鼠中于脑内分离。对通路选择可能基础的研究倾向于支持这样一种观点，即传出神经元利用完整的传入纤维作为其导航至不同感觉上皮的通道。
