National Health Commission, Key Laboratory of Birth Defect Prevention, Henan Scientific and Technical Institute of Reproductive Health, Zhengzhou, China.
School of Nursing and Health, Henan University, Kaifeng, China.
Int J Dev Neurosci. 2021 Apr;81(2):209-219. doi: 10.1002/jdn.10091. Epub 2021 Jan 24.
In order to understand the relationships between neocortical lamination and cell cycle, various cells, such as neural stem cell, migrating postmitotic neuron, Cajal-Retzius (CR) cell, and mature pyramidal cell in various cell phases were investigated in mouse cortices.
With mouse neocortex and hippocampus, the immunofluorescent labeling, BrdU assay, and DiI tracing technique were implemented in the study.
(1) During mouse development, the neocortex expressed different proteins, such as FOXP2, CDP, and Nestin, which could be used as the markers for cortical lamination. (2) The neural stem cells were mainly located in the subventricular zone, with the expressions of Nestin, Cyclin A2, Cyclin E1, and CDT1, suggesting that they were in the repeated cell cycle. Furthermore, the migrating neurons in the neocortex were Cyclin D1- (G1 phase-specific marker) positive, suggesting that they were in the G1 phase. However, Pyramidal cells that developed from postmitotic migrating neurons and settled in the cortical plate were Cyclin D1- negative, suggesting that they were in the G0 phase. (3) Reelin positive CR cells appeared in the molecular layer of the neocortex in early embryonic day (E10), which could express Cyclin A2, Cyclin E1, and CDT1 as pyramidal cells, but not Cyclin D1, suggesting that they may have exited the cell cycle and entered the G0 phase.
The neural migration, neural proliferation, and cell cycle alterations play an important role during cortical lamination. During the cortical development and lamination, the neural stem cells and migrating postmitotic neurons are in different cell cycle phases, but pyramidal cells and CR cells have exited the cell cycle.
为了了解新皮质分层与细胞周期之间的关系，研究人员调查了各种细胞，如神经干细胞、有丝分裂后迁移的神经元、Cajal-Retzius (CR) 细胞和处于不同细胞阶段的成熟锥体神经元。
在这项研究中，使用了小鼠大脑皮质和海马组织，实施了免疫荧光标记、BrdU 测定和 DiI 示踪技术。
(1) 在小鼠发育过程中，新皮质表达了不同的蛋白质，如 FOXP2、CDP 和 Nestin，可作为皮质分层的标志物。(2) 神经干细胞主要位于侧脑室下区，表达 Nestin、Cyclin A2、Cyclin E1 和 CDT1，表明它们处于反复的细胞周期中。此外，位于新皮质的迁移神经元呈 Cyclin D1 阳性（G1 期特异性标志物），表明它们处于 G1 期。然而，由有丝分裂后迁移神经元发育而来并定居在皮质板中的锥体神经元 Cyclin D1 阴性，表明它们处于 G0 期。(3) 早期胚胎 (E10) 期，新皮质的分子层出现 Reelin 阳性的 CR 细胞，它们可以表达与锥体神经元相同的 Cyclin A2、Cyclin E1 和 CDT1，但不表达 Cyclin D1，表明它们可能已经退出细胞周期并进入 G0 期。
神经迁移、神经增殖和细胞周期改变在皮质分层过程中起着重要作用。在皮质发育和分层过程中，神经干细胞和有丝分裂后迁移的神经元处于不同的细胞周期阶段，但锥体神经元和 CR 细胞已经退出细胞周期。
