Brain-region-specific humanized cortical interneuron mice

摘要 GABA能皮层中间神经元在大脑活动的平衡、同步和门控中起着关键作用。 通过抑制其他神经元。他们的功能障碍，特别是内侧神经节隆起(MGE)导致的功能障碍 CINS与多种神经发育性大脑疾病有关，如精神分裂症(SCZ)和 自闭症谱系障碍(ASD)。考虑到人类大脑和啮齿动物之间的差异 大脑导致了许多在啮齿动物身上得到验证的中枢神经系统(CNS)疗法的失败 为了更好地理解这些与CIN相关的机制，研究人类神经元是至关重要的 大脑紊乱。人类胎儿脑组织不能用于机制研究，但我们已经开发出一种 一种从多能干细胞高效生成MGE型人CIN均一群体的方法 (PSCs)指健康或疾病受试者。我们广泛地描述了它们的特征，并展示了它们的 真实性和功能性，使得研究复杂的收敛函数后果成为可能 在真实患者神经元中的遗传学，由于缺乏保守性，无法在小鼠神经元中进行研究 非编码区，大多数风险基因座都在那里。然而，体外培养的神经元缺乏其他关键的 脑环境的组成部分，如星形胶质细胞、少突胶质细胞、小胶质细胞和血管， 这会显著影响它们的功能。人们一直在努力优化体外培养系统以 通过添加其他脑细胞成分来更好地概括体内的生理环境，但有 他们在模拟活体情况方面仍然存在局限性。为了解决这个问题，在我们以前的 在这项研究中，我们开创了人类神经元-小鼠脑嵌合体的先河，以研究人类SCZ神经元在 生理环境。尽管我们能够成功地确定SCZ CIN的内在连接性 对于小鼠大脑的缺陷，我们无法分析移植神经元对大脑回路和 在移植的小鼠中存在健康的小鼠神经元所致的行为。因此，在这项拟议的研究中，我们 将对NodScid Gamma(NSG)小鼠进行脑区特异性CIN消融，然后替换 切除宿主CIN和人类CIN以产生特定区域的人源化CIN嵌合体。基于以前的 包括我们在内的研究表明，通过移植人类成功地恢复了受损的小鼠抑制 CINS，这些小鼠将允许我们分析移植的人类CIN对大脑回路和 在生理活体环境中的行为。这个新的生理模型系统将帮助我们 复杂脑部疾病的细胞类型和脑区域特异性疾病机制，以及对发育的帮助 新的治疗方法。

Abstract GABAergic cortical interneurons (cINs) play critical roles in balancing, synchronizing, and gating brain activity by inhibiting other neurons. Their malfunction, especially those of medial ganglionic eminence (MGE)-derived cINs, has been associated with various neurodevelopmental brain disorders, such as schizophrenia (SCZ) and autism spectrum disorders (ASD). Considering the fact that the divergence between human brains and rodent brains has resulted in the failure of many central nervous system (CNS) therapeutics validated in rodent models, it is critical to study human neurons to better understand the mechanisms of these cIN-associated brain disorders. Human fetal brain tissues are not accessible for mechanistic studies, but we have developed a method to efficiently generate homogeneous populations of MGE-type human cINs from pluripotent stem cells (PSCs) of healthy or diseased subjects. We have extensively characterized them and demonstrated their authenticity and functionality, making it possible to study the converging functional consequences of complex genetics in real patient neurons, which cannot be studied in mouse neurons due to a lack of conservation of non-coding regions, where most of risk loci are present. However, in vitro cultured neurons lack other critical components of the brain environment, such as astrocytes, oligodendrocytes, microglia and blood vessels, which can significantly impact their function. There have been efforts to optimize in vitro culture systems to better recapitulate in vivo physiological environments by adding other brain cellular components, but there are still limitations as to how closely they can simulate in vivo situations. To resolve this issue, in our previous study, we pioneered human neuron-mouse brain chimeras to study the function of human SCZ neurons in physiological environments. Although we were able to successfully identify SCZ cIN-intrinsic connectivity deficits in mouse brains, we were not able to analyze the impacts of grafted neurons on brain circuits and behaviors due to the presence of healthy mouse neurons in the grafted mice. Thus, in this proposed study, we will perform brain-region-specific cIN-ablation in NodScid gamma (NSG) mice, followed by the replacement of ablated host cINs with human cINs to generate region-specific humanized cIN chimeras. Based on previous studies, including ours, that show successful restoration of compromised mouse inhibition by grafted human cINs, these mice will allow us to analyze the functional impacts of grafted human cINs on the brain circuits and behaviors in physiological in vivo environments. This novel physiological model system will help us tease apart cell-type- and brain-region-specific disease mechanisms for complex brain disorders, and aid in developing novel therapeutics.