Zhu Yan, Yu Tao, Rao Yi
Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Dev Biol. 2004 Mar 1;267(1):153-64. doi: 10.1016/j.ydbio.2003.10.037.
We have studied the temporal and spatial control of cell migration from the external germinal layer (EGL) in the mammalian cerebellum as a model for cortical migration. Our results have demonstrated that embryonic EGL cells do not migrate into internal layers because they respond to a diffusible attractant in the meninges, the nonneural tissues covering the nervous system, and to a repellent in the neuroepithelium. Two developmental changes are important for postnatal EGL migration: the disappearance of the repellent in the inner layers and a switch in cellular responsiveness of EGL cells so that the postnatal EGL cells respond to the repellent, but not the attractant in the meninges. Besides revealing the signaling role of meninges in cortical development, our study suggests that an active mechanism is required to prevent cell migration, and that mechanisms of cell migration should be studied even in the absence of apparent changes in cell positions. We propose a model for the developmental control of neuronal migration in the cerebellar cortex.
我们以哺乳动物小脑外颗粒层（EGL）细胞迁移的时空控制为皮质迁移模型进行了研究。我们的结果表明，胚胎期的EGL细胞不会迁移到内层，因为它们对脑膜（覆盖神经系统的非神经组织）中的一种可扩散吸引剂以及神经上皮中的一种排斥剂产生反应。对于出生后EGL的迁移，有两个发育变化很重要：内层排斥剂的消失以及EGL细胞细胞反应性的转变，使得出生后的EGL细胞对排斥剂产生反应，但对脑膜中的吸引剂不产生反应。除了揭示脑膜在皮质发育中的信号作用外，我们的研究还表明，需要一种主动机制来阻止细胞迁移，并且即使在细胞位置没有明显变化的情况下，也应该研究细胞迁移机制。我们提出了一个小脑皮质神经元迁移发育控制的模型。
