Rapid changes in the distribution of GAP-43 correlate with the expression of neuronal polarity during normal development and under experimental conditions.
Rapid changes in the distribution of GAP-43 correlate with the expression of neuronal polarity during normal development and under experimental conditions.
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DOI：
10.1083/jcb.110.4.1319
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发表时间：
1990-04
影响因子：
7.8
通讯作者：
Banker, G
中科院分区：
文献类型：
--
作者：
Goslin, K;Banker, G
培养中生长的海马神经元最初延伸出几个短的小突起，这些突起有可能成为轴突或树突。当这些小突起中的一个开始迅速伸长，成为轴突时，极性的第一次表达发生。在轴突长出之前，生长相关蛋白GAP-43在小突起的生长锥中均匀分布;一旦极性已经建立，其优先集中在轴突生长锥中（Goslin，K.，D. Schreyer，J. Skene，and G.银行家1990.神经科学杂志10：588 - 602）。为了确定GAP-43的选择性分离何时开始，我们通过视频显微镜观察单个细胞，一旦轴突可以区分就将其固定，并通过免疫荧光显微镜定位GAP-43。个别的次要过程中获得轴突生长特性的一段时间内的30 - 60分钟，和GAP-43成为选择性地集中到这些过程的生长锥具有同样快速的时间过程。我们还研究了轴突横断后GAP-43分布的变化。在远离索马的轴突横切后，神经元极性保持不变，并且原始轴突几乎立即开始再生。在这种情况下，GAP-43在12 - 30分钟内选择性地集中在新的轴突生长锥中。相反，当轴突在靠近索马处被横切时，极性丧失;原始轴突很少再生，并且在新的轴突出现之前有显著的延迟。在这种情况下，GAP-43在新的生长锥中积累的速度要慢得多，这表明它正在进行的选择性轴突路由已被切断破坏。这些结果表明，GAP-43的选择性隔离的生长锥的一个单一的过程是密切相关的轴突生长特性的收购，因此，与极性的表达。
Hippocampal neurons growing in culture initially extend several, short minor processes that have the potential to become either axons or dendrites. The first expression of polarity occurs when one of these minor processes begins to elongate rapidly, becoming the axon. Before axonal outgrowth, the growth-associated protein GAP-43 is distributed equally among the growth cones of the minor processes; it is preferentially concentrated in the axonal growth cone once polarity has been established (Goslin, K., D. Schreyer, J. Skene, and G. Banker. 1990. J. Neurosci. 10:588-602). To determine when the selective segregation of GAP-43 begins, we followed individual cells by video microscopy, fixed them as soon as the axon could be distinguished, and localized GAP-43 by immunofluorescence microscopy. Individual minor processes acquired axonal growth characteristics within a period of 30- 60 min, and GAP-43 became selectively concentrated to the growth cones of these processes with an equally rapid time course. We also examined changes in the distribution of GAP-43 after transection of the axon. After an axonal transection that is distant from the soma, neuronal polarity is maintained, and the original axon begins to regrow almost immediately. In such cases, GAP-43 became selectively concentrated in the new axonal growth cone within 12-30 min. In contrast, when the axon is transected close to the soma, polarity is lost; the original axon rarely regrows, and there is a significant delay before a new axon emerges. Under these circumstances, GAP-43 accumulated in the new growth cone much more slowly, suggesting that its ongoing selective routing to the axon had been disrupted by the transection. These results demonstrate that the selective segregation of GAP-43 to the growth cone of a single process is closely correlated with the acquisition of axonal growth characteristics and, hence, with the expression of polarity.