大脑皮层神经元放射状迁移导向机制的新发现  

New Mechanism of Guiding Radial Migration of Cortical Neurons

作　　者：陈罡[1] Jian Sima 金明[1] 王开宇[1] 薛晓静[1] 郑望[1] 丁玉强[1] 袁小兵[1] 

机构地区：[1]中科院上海生命科学研究院神经科学研究所神经科学国家重点实验室

出　　处：《中国基础科学》2008年第2期25-26,共2页China Basic Science

基　　金：国家重点基础研究发展计划项目(2006CB806600;2006CB943903);国家自然科学基金(30300103;30721004);上海启明星计划项目(06QH14017)

摘　　要：Postmitotic neurons in the developing cortex migrate along radial glial fibers to their proper location in the cortical plate and form the layered structure.Here we report that the radial migration of rat layer II/III cortical neurons requires guidance by the extracellular diffusible factor Semaphorin-3A(Sema3A).This factor is expressed in a descending gradient across the cortical layers,whereas its receptor neuropilin-1(NP1)is highly expressed in migrating neurons.Downregulation or conditional knockout of NP1 in newborn cortical neurons impedes their radial migration by disrupting their radial orientation during migration without altering their cell fate.Studies in cultured cortical slices further show that the endogenous gradient of Sema3A is required for the proper migration of newborn neurons.In addition,transwell chemotaxis assays show that isolated newborn neurons are attracted by Sema3A.Thus,Sema3A may function as a chemoattractive guidance signal for the radial migration of newborn cortical neurons toward upper layers.Postmitotic neurons in the developing cortex mi- grate along radial glial fibers to their proper location in the cortical plate and form the layered structure. Here we report that the radial migration of rat layer Ⅱ/Ⅲ cortical neurons requires guidance by the extracellular diffusible factor Semaphorin-3A （Sema3A）. This factor is expressed in a descending gradient across the cortical layers, whereas its receptor neuropilin-1 （ NP1 ） is highly expressed in migrating neurons. Downregulation or conditional knockout of NP1 in newborn cortical neurons impedes their radial migration by disrupting their radial orientation during migration without altering their cell fate. Studies in cultured cortical slices further show that the endogenous gradient of Sema3A is required for the proper migration of newborn neurons. In addition,transwell chemotaxis assays show that isolated newborn neurons are attracted by Sema3A. Thus, Sema3A may function as a chemoattractive guidance signal for the radial migration of newborn cortical neurons toward upper layers.

关 键 词：大脑皮层 神经系统 哺乳动物 脑结构 

分 类 号：Q426[生物学—神经生物学] Q42[生物学—生理学]