Inhibitory Mechanism by Polysialic Acid for Lamina-Specific Branch Formation of Thalamocortical Axons
Inhibitory Mechanism by Polysialic Acid for Lamina-Specific Branch Formation of Thalamocortical Axons
复制标题
聚唾液酸对丘脑皮质轴突层特异性分支形成的抑制机制
DOI：
10.1523/jneurosci.20-24-09145.2000
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
T. Seki
中科院分区：
文献类型：
--
作者：
N. Yamamoto;Kayo Inui;Yuki Matsuyama;A. Harada;K. Hanamura;F. Murakami;E. S. Ruthazer;U. Rutishauser;T. Seki
在发育过程中，丘脑皮质轴突主要在新皮质的第四层形成乔木。在化学固定的皮质切片旁边生长的大鼠丘脑外植体的培养中，研究了这种特定的椎板分支形成。在体外培养一周后，丘脑轴突在固定的皮质切片的靶层形成分支，而与内生的方向无关。这一体外系统可以直接评估膜相关分子对丘脑轴突分支形成的贡献。为此，本研究使用了三种酶的扰动：软骨素酶、磷脂酰肌醇磷脂酶C或多唾液酸(PSA)特异的内尿氨酸酶(Endo N)。皮层经Endo-N处理后，分支点数量显著增加，而分枝尖端长度明显缩短。此外，分支点到目标层的局部化程度也大大减弱。除了软骨素酶处理使枝条尖端缩短的程度与Endo-N处理相同外，其他两种酶处理并未改变枝条形成的这些特征。这些结果表明，膜结合成分参与了丘脑皮质轴突的板层特异性分支的形成，特别是PSA部分通过抑制不适当层中的分支出现来促进板层的特异性。
During development, thalamocortical axons form arbors primarily in layer 4 of the neocortex. This lamina-specific branch formation was studied in cultures of rat thalamic explants grown next to chemically fixed cortical slices. After a week in vitro, thalamic axons formed branches specifically in the target layer of fixed cortical slices, regardless of the orientation of the ingrowth. Thisin vitro system permits a direct assessment of contributions of membrane-associated molecules to thalamic axon branch formation. To this end, the present study uses three enzymatic perturbations: chondroitinase, phosphatidylinositol phospholipase C, or the polysialic acid (PSA)-specific endoneuraminidase (endo N). With endo N pretreatment of cortex, the number of branch points was increased significantly, whereas branch tip length was decreased. In addition, the localization of branch points to the target layer was weakened considerably. These features of branch formation were not altered by the other two enzymatic treatments, except that branch tips were shortened by chondroitinase treatment to the same extent as in endo N treatment. These results suggest that membrane-bound components are involved in lamina-specific branch formation of thalamocortical axons, and in particular that PSA moieties contribute to laminar specificity by inhibiting branch emergence in inappropriate layers.
通过抑制性膜结合分子控制地形视网膜轴突分支。
DOI：
10.1126/science.8047886
发表时间：
1994
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Roskies,AL;O'Leary,DD
通讯作者：
O'Leary,DD
影响因子：
4.6
作者：
X. Yin;M. Watanabe;U. Rutishauser
通讯作者：
X. Yin;M. Watanabe;U. Rutishauser