The development of a simple scaffold of axon tracts in the brain of the embryonic zebrafish, Brachydanio rerio.
The development of a simple scaffold of axon tracts in the brain of the embryonic zebrafish, Brachydanio rerio.
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发表时间：
1990
期刊：
影响因子：
4.6
通讯作者：
Stephen W. Wilson;L. S. Ross;T. Parrett;S. Easter
中科院分区：
文献类型：
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作者：
Stephen W. Wilson;L. S. Ross;T. Parrett;S. Easter
我们研究了受精后1至2天内斑马鱼胚胎前脑和中脑的神经元分化和轴突束的形成。轴突可视化与三种技术;免疫细胞化学（使用HNK-1和抗乙酰化微管蛋白抗体）和辣根过氧化物酶（HRP）标记在整个安装的大脑，和透射电子显微镜。分化监测乙酰胆碱酯酶（AChE）的组织化学染色。这些独立的方法表明，一个简单的网格束和连合形成的最初轴突支架的大脑。在第1天，存在嗅神经、四个连合、它们的相关束和其他三个非连合束。到第2天，这些束和连合都大大扩大，此外，视神经和束，三个新的连合及其相关的束已经增加。HRP在不同部位的小应用揭示了这些最早期轴突的起源和投射。逆行标记的细胞体起源于AChE活性也呈阳性的区域。在第1天，HRP标记的轴突从嗅基板经嗅神经到达端脑背侧，从端脑进入前连合束并到达间脑后连合区，从后脑经中脑腹侧和间脑到达间脑后连合区，从中脑腹侧和间脑到达间脑后连合区。（4）从间脑背侧（在骨骺内或附近）到后连合束：（5）从中脑腹侧和头侧经后连合。在第2天发现了三个新的投射：（1）从视网膜通过视后连合到顶盖;（2）从端脑到对侧间脑;（3）从端脑到腹曲。这些结果表明，在第1天，斑马鱼的大脑是令人印象深刻的简单，有几个小的，分离良好的管道，但到第2天，大脑已经相当复杂。大多数额外的轴突被添加到预先存在的神经束上，而不是开创性的新轴突，这支持了其他轴突在早期中枢神经系统（CNS）轴突的引导中发挥关键作用的观点。
We have examined neuronal differentiation and the formation of axon tracts in the embryonic forebrain and midbrain of the zebrafish, between 1 and 2 days postfertilisation. Axons were visualised with three techniques; immunocytochemistry (using HNK-1 and antiacetylated tubulin antibodies) and horseradish peroxidase (HRP) labelling in whole-mounted brains, and transmission electron microscopy. Differentiation was monitored by histochemical staining for acetylcholinesterase (AChE). These independent methods demonstrated that a simple grid of tracts and commissures forms the initial axon scaffold of the brain. At 1 day, the olfactory nerve, four commissures, their associated tracts and three other non-commissural tracts are present. By 2 days, these tracts and commissures have all greatly enlarged and, in addition, the optic nerve and tract, and three new commissures and their associated tracts have been added. Small applications of HRP at various sites revealed the origins and projections of some of these earliest axons. Retrogradely labelled cell bodies originated from regions that were also positive for AChE activity. At 1 day, HRP-labelled axons were traced: (1) from the olfactory placode through the olfactory nerve to the dorsal telencephalon; (2) from the telencephalon into the tract of the anterior commissure and also to the postoptic region of the diencephalon; (3) from the hindbrain through the ventral midbrain and diencephalon to the postoptic commissure; (4) from the dorsal diencephalon (in or near the epiphysis) to the tract of the postoptic commissure; (5) from ventral and rostral midbrain through the posterior commissure. Three new projections were demonstrated at 2 days: (1) from the retina through the tract of the postoptic commissure to the tectum; (2) from the telencephalon to the contralateral diencephalon; and (3) from the telencephalon to the ventral flexure. These results show that at 1 day, the zebrafish brain is impressively simple, with a few small, well-separated tracts but by 2 days the brain is already considerably more complex. Most of the additional axons added onto pre-existent tracts rather than pioneered new ones supporting the notion that other axons play a crucial role in the guidance of early central nervous system (CNS) axons.