Yoshinaga Satoshi, Shin Minkyung, Kitazawa Ayako, Ishii Kazuhiro, Tanuma Masato, Kasai Atsushi, Hashimoto Hitoshi, Kubo Ken-Ichiro, Nakajima Kazunori
Department of Anatomy, Keio University School of Medicine, Shinjuku, Tokyo 160-8582, Japan.
Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan.
iScience. 2021 Mar 6;24(4):102277. doi: 10.1016/j.isci.2021.102277. eCollection 2021 Apr 23.
In the mammalian cerebral neocortex, different regions have different cytoarchitecture, neuronal birthdates, and functions. In most regions, neuronal migratory profiles are speculated similar based on observations using thymidine analogs. Few reports have investigated regional migratory differences from mitosis at the ventricular surface. In this study, we applied FlashTag technology, in which dyes are injected intraventricularly, to describe migratory profiles. We revealed a mediolateral regional difference in the migratory profiles of neurons that is dependent on developmental stage; for example, neurons labeled at embryonic day 12.5-15.5 reached their destination earlier dorsomedially than dorsolaterally, even where there were underlying ventricular surfaces, reflecting sojourning below the subplate. This difference was hardly recapitulated by thymidine analogs, which visualize neurogenic gradients, suggesting a biological significance different from the neurogenic gradient. These observations advance our understanding of cortical development and the power of FlashTag in studying migration and are thus resources for future neurodevelopmental studies.
在哺乳动物的大脑新皮层中，不同区域具有不同的细胞结构、神经元出生日期和功能。在大多数区域，基于使用胸腺嘧啶类似物的观察结果推测神经元迁移模式相似。很少有报告研究从脑室表面有丝分裂开始的区域迁移差异。在本研究中，我们应用了FlashTag技术（即向脑室内注射染料）来描述迁移模式。我们揭示了神经元迁移模式存在内侧到外侧的区域差异，这种差异取决于发育阶段；例如，在胚胎第12.5 - 15.5天标记的神经元，即使在有潜在脑室表面的情况下，到达背内侧目的地的时间也比背外侧早，这反映了它们在板下层下方的停留。胸腺嘧啶类似物难以重现这种差异，胸腺嘧啶类似物可显示神经源性梯度，这表明其生物学意义不同于神经源性梯度。这些观察结果增进了我们对皮质发育的理解以及FlashTag在研究迁移方面的作用，因此可为未来的神经发育研究提供参考。
