前脑胆碱能神经元死亡是老年痴呆症患者的重要神经病理学特征。胆碱能神经元移植可望用于治疗老年痴呆症，但是目前尚缺乏有效手段获得可应用的前脑胆碱能神经元。多能干细胞具有分化为人体任何一种细胞的潜能，但其体外分化研究依赖发育生物学线索的指导。目前对胆碱能神经元发育的认识还非常有限，这直接制约了通过多能干细胞分化获得该神经元。申请人前期研究发现多能干细胞来源的前脑神经干细胞在Sonic Hedgehog诱导下可高效分化为腹侧前脑谷氨酰胺能神经元，但是几乎不产生胆碱能神经元；这提示胆碱能神经元分化依赖腹侧化信号之外其他调控信号的作用。本课题拟借助小分子和蛋白因子的组合筛选阐释促进胆碱能神经元分化的分子基础；实现在化学成分明确条件下人多能干细胞向胆碱能神经元的高效分化；并通过学习记忆障碍模型评价细胞移植后的功能。本课题将有助于深入认识胆碱能神经元的发育机制，并为老年痴呆症等疾病的细胞治疗提供细胞来源。

The death of forebrain cholinergic neurons is primary neuropathology feature of Alzheimer's disease (AD). Transplantation of cholinergic neurons could be promising strategy for AD treatment. However, the shortage of transplantable cholinergic neurons was one of the main bottlenecks of this treatment. Pluripotent stem cells can generate any cell types of adults. The in vitro differentiation of pluripotent stem cells relies on the developmental studies of lineage commitment. However, we currently know little about the development of cholinergic neurons, which represents a major hurdle in generating cholinergic neurons from human pluripotent stem cells. Previously, we found human pluripotent stem cell-derived forebrain neural stem cells can give rise to GABA neurons at very high efficiency under the patterning of Sonic Hedgehog. However, production of cholinergic neurons under same condition was very low. These results indicated other critical instructive signals are required for cholinergic neuron differentiation. In this project, we will carry out reiterative chemical/growth factor screening to probe the mechanism of cholinergic neuron differentiation and to develop efficient induction of cholinergic neurons from human pluripotent stem cells. Then, in vivo transplantation will be performed to test the potential of these cholinergic neurons in alleviating memory and learning disability in a mouse model. This project would provide useful information about cholinergic neuron development, and valuable cell source of cholinergic neurons for AD cell therapy.