Shiga T, Oppenheim R W, Grumet M, Edelman G M
Department of Neurobiology and Anatomy, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27103.
Brain Res Dev Brain Res. 1990 Sep 1;55(2):209-17. doi: 10.1016/0165-3806(90)90202-a.
The pattern of expression of the neuron-glia cell adhesion molecule (Ng-CAM) among the presumptive intersegmental interneurons in the early chick embryo spinal cord (stage 14-19) was examined using whole-mount and cryostat preparations double-stained with anti-Ng-CAM antibody and a neuron-specific anti-beta-tubulin antibody. In brachial segments, primitive longitudinal cells (PL-cells), located in the ventrolateral region of the spinal cord, express Ng-CAM both on their cell bodies and longitudinally growing axons, beginning at Hamburger-Hamilton stage 15 (embryonic day (E) 2.5). Shortly thereafter, at stage 16, circumferential cells (C-cells), composed of associational and commissural interneurons in the dorsolateral and lateral region of the spinal cord begin to express Ng-CAM both on their cell bodies and their axons which project ventrally along the lateral surface of the spinal cord. In the following stages. PL-cells express Ng-CAM strongly and begin to fasciculate to form a longitudinal fascicle in the ventrolateral marginal region of the spinal cord. C-Cells either extend their Ng-CAM-positive axons ventrally without fasciculation to join the Ng-CAM positive ipsilateral longitudinal fascicle at stage 17 (which has already been formed by PL-cell axons), or they cross the midline to join the Ng-CAM positive contralateral longitudinal fascicle after growing through the floor plate at stage 19. By stage 19, cell bodies and proximal segments of the C-cell axons exhibit decreased Ng-CAM expression, whereas the distal segment of these axons, including growth cones, strongly express Ng-CAM. Many contacts were observed between Ng-CAM-positive growth cones and axons in the ventral region of the spinal cord, both within the longitudinal fascicle and the floor plate region, suggesting the involvement of Ng-CAM in neurite-neurite interactions.(ABSTRACT TRUNCATED AT 250 WORDS)
利用抗 Ng-CAM 抗体和神经元特异性抗β-微管蛋白抗体双重染色的整装标本和冰冻切片，研究了鸡胚早期（14-19 期）脊髓中假定的节间中间神经元之间神经元-胶质细胞黏附分子（Ng-CAM）的表达模式。在臂节中，位于脊髓腹外侧区域的原始纵向细胞（PL 细胞）从汉堡-汉密尔顿 15 期（胚胎第 2.5 天）开始，在其细胞体和纵向生长的轴突上均表达 Ng-CAM。此后不久，在 16 期，由脊髓背外侧和外侧区域的联合和连合中间神经元组成的圆周细胞（C 细胞）开始在其细胞体和沿脊髓外侧表面向腹侧投射的轴突上表达 Ng-CAM。在随后的阶段，PL 细胞强烈表达 Ng-CAM，并开始在脊髓腹外侧边缘区域成束形成纵向束。C 细胞要么在 17 期将其 Ng-CAM 阳性轴突无束状地向腹侧延伸，以加入已由 PL 细胞轴突形成的 Ng-CAM 阳性同侧纵向束，要么在 19 期穿过底板生长后穿过中线加入 Ng-CAM 阳性对侧纵向束。到 19 期，C 细胞轴突的细胞体和近端节段 Ng-CAM 表达降低，而这些轴突的远端节段，包括生长锥，强烈表达 Ng-CAM。在脊髓腹侧区域的纵向束和底板区域内，均观察到 Ng-CAM 阳性生长锥与轴突之间有许多接触，这表明 Ng-CAM 参与了神经突-神经突相互作用。（摘要截短于 250 字）
