GABA Driven Depolarization in Early Human Cortical Development.

项目总结： 人多能干细胞为研究正常和多能干细胞提供了一个有吸引力的实验平台 人类神经网络发育异常。在体外，诱导的多能干细胞(IPSC)已经 用于研究早期发育机制和突触发生的初始阶段 赛道编队。IPSC还为研究人类神经回路提供了诱人但尚未实现的潜力 在试管中。我们在体外模拟人类大脑皮层环路发育的努力表明 差异化可以分为5个步骤，包括：1)构图 神经外胚层和早期神经发生-3周后明显；2)神经母细胞迁移和 初步分化为区域特异性神经元亚型-6周后明显；3)发育 自发电活动和早期突触发生--2-3个月后明显；4)初期 星形胶质细胞的出现和内部强烈而同步的振荡爆发的形成 大型集合-在3-5个月内明显；5)大型超同步神经元的分辨率 集合成更小的、谨慎地发射的子集合-偶尔在超过6点之后观察到 月份。体内出现少突胶质前体细胞和轴突髓鞘尚未见报道 被观察到或报告过。尽管令人欣慰的是证实了人类特有的发育 IPSC模型中的程序在时间上是完整的，漫长的时间线使其研究具有挑战性 发育机制迟缓或回路功能成熟。 这个项目的最终目标是开发方法来加速形成 具有成熟突触的高度相互连接的人类神经元。同步振荡神经元 活跃性似乎是神经系统发育过程中的一种基本的和必要的过渡性特征。 视网膜、大脑皮层和脊髓等结构中的年轻神经元经历时期 具有高度的连通性和强大的神经元活性，随后被提炼成特定的 突触连接和受调控的动作电位活动。体外发育的人类神经元 可能需要获得这些相同的特性才能成为功能性神经元 网络。我们的初步工作表明，这些专有财产是由 不同发育时期和/或不同区域产生的细胞类型的相互作用 发育中的大脑。这项提案中的实验集中在概括这些内容的新方法上 相互作用加速同步振荡爆发的获得并进一步促进 IPSC衍生的人类神经网络的成熟。

Project Summary: Human pluripotent stem cells provide an attractive experimental platform for studying the normal and abnormal development of human neural networks. In vitro, induced pluripotent stem cells (iPSC) have been used to study early developmental mechanisms and the initial stages of synaptogenesis and circuit formation. iPSC also offer the tantalizing but unrealized potential to study human neural circuits in vitro. Our efforts to model the development of human cortical circuits in vitro indicate that differentiation can be segmented into a 5-step progression involving: 1) patterning of the neuroectoderm and early neurogenesis - robustly evident after 3 weeks; 2) neuroblast migration and initial differentiation into regionally-specific neuronal subtypes - evident after 6 weeks; 3) development of spontaneous electrical activity and early synaptogenesis – evident after 2-3 months; 4) initial appearance of astrocytes and the formation of vigorous and synchronous oscillatory bursting within large ensembles – evident within 3-5 months; 5) resolution of large hypersynchronous neuronal ensembles into smaller, discreetly firing sub-ensembles – occasionally observed after more than 6 months. Appearance of oligodendrocyte progenitors and myelination of axons seen in vivo has not yet been observed or reported. Although it is comforting to confirm that human-specific developmental programs are temporally intact in iPSC models, the protracted timeline makes it challenging to study late developmental mechanisms or mature circuit function. The ultimate goal of this project is to develop methods to accelerate the formation of networks of highly interconnected human neurons with mature synapses. Synchronized and oscillatory neuronal activity appears to be a fundamental and obligate transitional property of developing nervous systems. Young neurons in structures as diverse as retina, cerebral cortex and spinal cord experience periods of high connectivity and robust neuronal activity that are subsequently refined to produce specific synaptic connections and regulated action potential activity. Human neurons developing in vitro presumably require the acquisition of these same properties in order to become functional neuronal networks. Our preliminary work suggests that these obligate properties are acquired by the interactions of cell types generated at different times in development and/or from different regions of the developing brain. Experiments in this proposal focus on novel methods that recapitulate these interactions to accelerate the acquisition of synchronous oscillatory bursting and promote the further maturation of iPSC-derived human neural networks.