Letourneau P C, Wire J P
Department of Cell Biology and Neuroanatomy, University of Minnesota, Minneapolis 55455, USA.
J Neurocytol. 1995 Mar;24(3):207-23. doi: 10.1007/BF01181535.
Microtubules play a role important in regulating cell shape and in mediating organelle movements. These functions are especially important in elaborately branched neurons, which have many stable microtubules that are resistant to cold and to microtubule depolymerizing drugs. We examined the three-dimensional organization of microtubules in cell bodies of cultured chick embryo sensory neurons, using confocal laser scanning microscopy. Microtubules were visualized with antibodies against alpha-tubulin and post-translationally modified forms of alpha-tubulin that accumulate in older microtubules. Optical sections were collected through neuronal somata, and the images were reconstructed in three dimensions. In neuronal perikarya a dense network of older microtubules is co-localized with the Golgi apparatus. This complex of the Golgi and older microtubules usually lies beneath the cell nucleus and is oriented toward the substratum. From this region, older microtubules extend into each neurite. A cage of older microtubules extends around the nucleus to the top of the perikaryon. The stability of these microtubules was confirmed by their resistance to the depolymerizing drug, nocodazole. This arrangement of stable microtubules in a developing neuron provides a supporting cytoskeleton and a transport pathway for movement of cytoplasmic components between the Golgi apparatus, the perikaryon and developing neurites.
微管在调节细胞形状和介导细胞器运动方面发挥着重要作用。这些功能在高度分支的神经元中尤为重要，这类神经元有许多对低温和微管解聚药物具有抗性的稳定微管。我们使用共聚焦激光扫描显微镜检查了培养的鸡胚感觉神经元细胞体中微管的三维组织。用针对α-微管蛋白以及在较老微管中积累的α-微管蛋白翻译后修饰形式的抗体使微管可视化。通过神经元胞体收集光学切片，并对图像进行三维重建。在神经元胞核周围，较老微管的致密网络与高尔基体共定位。高尔基体和较老微管的这个复合体通常位于细胞核下方并朝向基质。从这个区域，较老微管延伸到每个神经突中。一个由较老微管构成的笼子围绕细胞核延伸至胞核周围体的顶部。这些微管对解聚药物诺考达唑的抗性证实了它们的稳定性。发育中的神经元中这种稳定微管的排列为高尔基体、胞核周围体和发育中的神经突之间的细胞质成分运动提供了一个支持性细胞骨架和一条运输途径。
