Aizawa Hidenori, Goto Midori, Sato Tomomi, Okamoto Hitoshi
Laboratory for Developmental Gene Regulation, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Dev Cell. 2007 Jan;12(1):87-98. doi: 10.1016/j.devcel.2006.10.004.
The habenular neurons on both sides of the zebrafish diencephalon show an asymmetric (laterotopic) axonal projection pattern into the interpeduncular nucleus. We previously revealed that the habenula could be subdivided into medial and lateral subnuclei, and a prominent left-right difference in the size ratio of these subnuclei accounts for the asymmetry in its neural connectivity. In the present study, birth date analysis showed that neural precursors for the lateral subnuclei were born at earlier stages than those for the medial subnuclei. More neurons for the early-born lateral subnuclei were generated on the left side, while more neurons for the late-born medial subnuclei were generated on the right side. Genetic hyperactivation and repression of Notch signaling revealed that differential timing determines both specificity and asymmetry in the neurogenesis of neural precursors for the habenular subnuclei.
斑马鱼间脑两侧的缰核神经元向脚间核投射轴突时呈现出不对称（异位）的模式。我们之前发现，缰核可分为内侧和外侧亚核，这些亚核大小比例上显著的左右差异导致了其神经连接的不对称性。在本研究中，出生日期分析表明，外侧亚核的神经前体细胞比内侧亚核的神经前体细胞更早出生。左侧产生了更多早出生的外侧亚核神经元，而右侧产生了更多晚出生的内侧亚核神经元。Notch信号通路的基因过度激活和抑制表明，不同的时间决定了缰核亚核神经前体细胞神经发生的特异性和不对称性。
