Department of Neuroanatomy and Embryology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
Dev Dyn. 2023 Aug;252(8):1096-1112. doi: 10.1002/dvdy.572. Epub 2023 Mar 6.
The optic tectum is the main visual processor of nonmammalian vertebrates and relays visual information from the eye to the telencephalon via the tectofugal pathway. In the development of the avian optic tectum, while the multipolar neurons are arranged by tangential migration, the behavior of individual cells in tangential migration, neural differentiation, and cell fate remain unclear. Here, we pursued the transition of tangentially migrating cells and their involvement in visual circuit formation during chick development.
After tangential movement along the axons, the migrating cells relocated to the upper layers and turned back upon differentiation toward the multipolar neurons. The multipolar neurons are destined to differentiate into the stratum griseum central (SGC) neurons with the large dendritic field, which form the tectorotundal projection. Trans-synaptic virus labeling demonstrated that the tangentially migrating cells eventually participate in the tectofugal visual pathway.
These results indicate that tangential migration is a crucial process in the formation of the tectofugal visual pathway during the development of the optic tectum.
视顶盖是无脊椎动物的主要视觉处理器，通过顶盖出走途径将视觉信息从眼睛中继到端脑。在禽类视顶盖的发育过程中，虽然多极神经元通过切线迁移排列，但个别细胞在切线迁移、神经分化和细胞命运方面的行为仍不清楚。在这里，我们研究了小鸡发育过程中，切线迁移细胞的转变及其参与视觉回路形成的过程。
沿轴突进行切线运动后，迁移细胞重新定位到上皮层，并在向多极神经元分化时反转。多极神经元注定分化为具有大树突场的灰质层中央（SGC）神经元，形成顶盖回旋投射。跨突触病毒标记表明，切线迁移细胞最终参与了顶盖出走的视觉通路。
这些结果表明，切线迁移是视顶盖发育过程中顶盖出走视觉通路形成的关键过程。
