Advancing the functional maturity of brain organoids by synthetic afferentation.

项目概要 人类多能干细胞 (hiPSC) 是了解控制细胞的原理的强大工具。 人类大脑的发育和神经系统疾病的建模。最近一件重要的事 该技术的应用是生成三维（3D）脑细胞培养物或“类器官”。大脑 直到中晚期，类器官已被证明在结构、转录和功能方面具有相似性 妊娠期人类大脑与早产儿脑电图记录和人类转录组图谱进行比较。 目前，它们代表了与现有人类大脑组织最接近的细胞模型。虽然实力强大 产前发育机制探索系统试图促进大脑的成熟状态 类器官已被证明是增量的、不确定的或复制性差的。结果，大脑类器官系统 在很大程度上仍然不适合对产后大脑进行建模。迫切需要开发一种新的 生成适合研究后期发育阶段的大脑类器官模型。这个 该提案的重点是了解生理输入作为更强大的必要驱动因素的作用， 大脑类器官的可重复且成熟的生理活动状态。该项目将制定方法 用于引入与发育相关的输入并读出人脑类器官中的神经元活动。 其他系统的大量工作已经证实传入网络活动有助于建立、维持、 并完善活跃的功能性大脑回路。在这里，我们将测试一系列创新策略来替代或模仿 通过对人脑类器官的长时间模式刺激而丢失外部输入。然后我们将观察 由此对网络活动和基因表达产生影响。我们将把这些观察结果与现有数据进行基准比较 来自人类皮质类器官以及人类和啮齿动物大脑的集合。已建立的工具和方法 这里的目的是很容易适应其他器官系统的细胞培养模型，其中神经元输入 很重要。如果成功，该项目将建立一个新颖的平台来询问活动依赖性 成熟并将使人类进入更高级的大脑发育阶段和人类 神经系统和神经精神疾病状态。

PROJECT SUMMARY Human pluripotent stem cells (hiPSCs) are a powerful tool for understanding the principles that govern the development of the human brain and for modeling diseases of the nervous system. One important recent application of this technology is the generation of tri-dimensional (3D) brain cell cultures or "organoids." Brain organoids have been shown to develop structural, transcriptional, and functional similarities up to the mid-to-late gestation human brain as compared to preterm human EEG recordings and human transcriptome profiles. Currently they represent the closest cellular model to native human brain tissue available. While a powerful system for probing mechanisms of prenatal development attempts to advance the maturation state of brain organoids have proved to be incremental, inconclusive, or poorly reproduced. As a result, brain organoid systems remain largely inappropriate for modeling the postnatal brain. There is a significant need to develop a new generation of brain organoid models that are appropriate for interrogating later developmental stages. This proposal focuses on understanding the role of physiological inputs as a necessary driver of more robust, reproducible, and mature physiological states of activity in brain organoids. This project will develop approaches for introducing developmentally-relevant inputs and for reading out neuronal activity in human brain organoids. Extensive work from other systems has established that afferent network activity serves to establish, maintain, and refine active functional brain circuits. Here, we will test a series of innovative strategies to replace or mimic missing external inputs via prolonged patterned stimulation of human brain organoids. We will then observe the resulting effects on network activity and gene expression. We will benchmark these observations to existing data sets from human cortical organoids as well as the human and rodent brain. The tools and approaches established here are intended to be readily adapted to cell culture models of other organ systems for which neuronal inputs are important. If successful, this project will establish a novel platform for interrogating activity-dependent maturation and will enable access to more advanced stages of human brain development and human neurological and neuropsychiatric disease states.