Genetic single-cell mosaic analysis implicates ephrinB2 reverse signaling in projections from the posterior tectum to the hindbrain in zebrafish
Genetic single-cell mosaic analysis implicates ephrinB2 reverse signaling in projections from the posterior tectum to the hindbrain in zebrafish
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DOI：
10.1523/jneurosci.0883-07.2007
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发表时间：
2007-05-16
影响因子：
5.3
通讯作者：
Okamoto, Hitoshi
中科院分区：
文献类型：
--
作者：
Sato, Tomomi;Hamaoka, Takanori;Okamoto, Hitoshi
视顶盖是脊椎动物的视觉中枢。它从视网膜的浅层接收按地形图顺序排列的视觉输入，然后将深层的运动输出发送到后脑的运动前网状脊髓系统。虽然视网膜顶盖投射的地形图模式是众所周知的，但还不清楚顶盖如何在顶盖球束投射到后脑。在斑马鱼稳定转基因品系Tg(brn3α-HSP70：GFP)中观察到了视网膜顶盖和顶盖的投射。用单神经元标记系统，结合cre/loxP和Gal4/UAS系统，我们发现投射到菱形核2和6的顶盖神经元沿前后轴有明显的分布模式。此外，我们还发现ewitinB2a在增加神经元通过反向信号机制投射到菱形核2的概率方面起着至关重要的作用。这些结果可能为顶盖运动指令图提供神经解剖学和分子基础。
The optic tectum is a visual center in vertebrates. It receives topographically ordered visual inputs from the retina in the superficial layers and then sends motor outputs from the deeper layers to the premotor reticulospinal system in the hindbrain. Although the topographic patterns of the retinotectal projection are well known, it is not yet well understood how tectal efferents in the tectobulbar tract project to the hindbrain. The retinotectal and the tectobulbar projections were visualized in a zebrafish stable transgenic line Tg(brn3 alpha-hsp70:GFP). Using a single-neuron labeling system in combination with the cre/loxP and Gal4/UAS systems, we showed that the tectal neurons that projected to rhombomeres 2 and 6 were distributed with distinctive patterns along the anterior-posterior axis. Furthermore, we found that ephrinB2a was critically involved in increasing the probability of neurons projecting to rhombomere 2 through a reverse signaling mechanism. These results may provide a neuroanatomical and molecular basis for the motor command map in the tectum.