The human brain is characterized by an extraordinary complexity of neuronal and nonneuronal cell types, wired together into patterned neuronal circuits, which represent the anatomical substrates for the execution of high-order cognitive functions. Brain circuits' development and function is metabolically supported by an intricate network of selectively permeable blood vessels and finely tuned by short-range interactions with immune factors and immune cells. The coordinated cellular and molecular events governing the assembly of this unique and complex structure are at the core of intense investigation and pose legitimate questions about the best modeling strategies.Unceasing advancements in stem cell technologies coupled with recent demonstration of cell self-assembly capacity have enabled the exponential growth of brain organoid protocols in the past decade. This provides a compelling solution to investigate human brain development, a quest often halted by the inaccessibility of brain tissues and the lack of suitable models. We review the current state-of-the-art on the generation of brain organoids, describing the latest progresses in unguided, guided, and assembloids protocols, as well as organoid-on-a-chip strategies and xenograft approaches. High resolution genome wide sequencing technologies, both at the transcriptional and epigenomic level, enable the molecular comparative analysis of multiple brain organoid protocols, as well as to benchmark them against the human fetal brain. Coupling the molecular profiling with increasingly detailed analyses of the electrophysiological properties of several of these systems now allows a more accurate estimation of the protocol of choice for a given biological question. Thus, we summarize strengths and weaknesses of several brain organoid protocols and further speculate on some potential future endeavors to model human brain development, evolution and neurodevelopmental and neuropsychiatric diseases.

人类大脑的特点是神经元和非神经元细胞类型异常复杂，它们连接在一起形成图案化的神经元回路，这些神经元回路代表执行高阶认知功能的解剖学基础。大脑回路的发育和功能由复杂的选择性渗透血管网络提供代谢支持，并通过与免疫因子和免疫细胞的短程相互作用进行微调。控制这种独特而复杂结构组装的协调细胞和分子事件是深入研究的核心，并提出了关于最佳建模策略的合理问题。干细胞技术的不断进步，加上最近细胞自组装能力的证明，使大脑类器官协议在过去十年中呈指数级增长。这为研究人类大脑发育提供了一个令人信服的解决方案，但由于脑组织的不可接近性和缺乏合适的模型，这一探索经常被搁置。我们回顾了大脑类器官生成的当前最新技术，描述了非引导、引导和组装方案的最新进展，以及类器官芯片策略和异种移植方法。转录和表观基因组水平的高分辨率全基因组测序技术能够对多个大脑类器官协议进行分子比较分析，并将其与人类胎儿大脑进行基准测试。将分子分析与对其中几个系统的电生理特性的越来越详细的分析相结合，现在可以更准确地估计给定生物学问题的选择方案。因此，我们总结了几种大脑类器官协议的优缺点，并进一步推测了一些潜在的未来努力来模拟人类大脑发育、进化以及神经发育和神经精神疾病。