Developmental Biology第三章神经系统的发育Developmental Biology问答题1. 试述原肠化过程中的细胞运动有哪些?2. 斑马鱼胚盾等的作用是什么?三个胚层的分化情况如何?Developmental Biology一、神经管的形成神经管(neuraltube)是中枢神经系统的原基，其形成称为 neumlation。其方式分primary neurulation和 secondary neumlation两种。1. Primary neurulation:由外胚层细胞增殖.内陷并最终离开外胚层表面而形!=成中空的神经管。绝大多数脊椎动物前部神经管的形成采 用此种方式。Developmental Biology外胚层细胞的命运：背部中线区的细胞将形成脑和脊髓；中线区 外侧的细胞将生成皮肤；上述二者相交处的细胞为神经靖细胞(neural crest),它们将迁移各处形成外周神经元、色素细胞、神经胶质细胞等。Figure 人2Nc-urdl izlKeuniljticrt in amphibians and amnintcs. (A) niaranimaiic rcpreeiitati precursory 吋 the neural cgt (black) or 恥 prvcuibors of the epidermis (cnlir). Tlie echtdrrm folds in at the most dorsal point, forming an outer epidermis and an inner neural lube connected by neural cnst cells. (B) Iwhutymicrographs of neurulation in a 2nldy hi Neural tube formation swn in transverse emss sFormslion of iieu 邑Qab occurs whITn presumpHue epQlqrmiLS-F move TnlE-y surd ? ceiU曾*fse cmbrvQ This Pre5umle cp&nsis p 伫hg -hmrurd- p&aEkkr = M K3 (m 歹子勺 mid-me co【ls2.5-e rlpcs 一 pluh? ?0 floo p-n-Qccus) PB.anchored-rQ he nohKhorct54? mnira- fohdg HrGri-cuared These mou巾 me2v- appearcbe 口 m=ced 孝 fhT:mwi2-=y mewing Epidermis drags 一h? ne仁昱一 prg wi?.FrcsE一5-gB-bhcCJpposEon of _h巾 mg 二okhn-二 1- llw Blve 王罟7專wh刁包jSLhinge poinb MHPLnd【he fwo dorsosrol hin芒 POS*OAS 二 he DLHPL rhm IwwrSLPM_e cheMlgE fhvir h*=Krhiind ?nsrict M h2.r&pk:es Developmei神经管形成的扫描电镜图Figure 7.8S；annng electron micrograph t nptir.il tube formal ion in the chick cmbrvn. (A) Xr.nal j;n)vr sur reminded !?v ineseiKhvinal ccll (L5) l longdkxivp;iln?liolIpriil il lubv U1Vvpl Vi ml *.rll aiv bi onht 1i thr midliiu* cl ihvvmbrvo. The Mill*cellbformn hinge at the bottom vf the tube, while thv neural pldk* cdls (ittacln*d k the baxii area of thv surkwc n todrnn form lhe dorsolatcRil liingv regionb-. 1 hesr lb ret* hinges tdn be sevi 1 as furroub. (C Nvu ral tube formation i、compk4ti. The tells that Ihid been lhe aeiirdl plRe arc ngr叩】z ctiurtev of K. W. Tincv.)Developmental Biology神经管与相邻外胚层细胞分离可能与细胞粘连分子有关Developmental BiologyDevelopmental BiologyCadhttrin tzpre&eidn during neural tube kumalicm h 1 Xmwws efrbrroDevelopmental BiologyDevelopmental BiologyFig. &.31 Expression ol cell adhstori molecules during neural tube formation in Xenopus The ccHs of lh& neural plale express N-cadherin and the adjacon? ectoderm CKprass&s E-cadheriil. II Ncadliftrri is rmsxpressfid in the ectoderm on one 勺tfc. Urtire is u failure dI Hie neural lune to曰1lhat site right panel).Developmental Bioneural foldmesenchymeneural groovenotochordmesodermhead fold神经管沿A P轴线依次 闭合，完成形 成过程。neural plateendodermneural toldneural grooveintermediate I mesoderm coekxn somatic mesoderm splanchnic ” mesoderm somiteneural dsHensen s nodemesodermprimitive groove primitive ridge primitive streakFig. 2.17 Development of the neural tube and mesoderm in the chick embryo. Once the notochord has formed neurulatio n begins .following notochord formation in an anterior to posterior direction. The figure shows a series of sections along the anteroposterior axis of a chick embryo. Neural tube formation is well advanced at the anterior end (top two sections), where the head fold has already separated the fuiure head from the rest of the blastoderm and the ventral body fold has brought endoderm from both sides of the body together to form the gut. During neurulation,