A New Model System for Adult Neurogenesis

项目总结 在发育和动态平衡中，关键器官系统的祖细胞干细胞经常分裂 不对称的。记忆的形成涉及成年神经发生，其中祖细胞干细胞在 成人大脑不对称分裂以产生新生神经元。形成和回忆特定事物的能力 记忆对于我们的生存是不可或缺的。患有神经退行性疾病的患者 阿尔茨海默氏症表现出严重的学习和记忆障碍。因此，阐明发展的 记忆形成的机制基础对识别和预防过程至关重要 会导致脑部疾病。我们的长期目标是了解 在成人大脑中产生新的神经元。我们已经建立了一种新的模式生物来解决这个问题 问题是，这个问题结合了哺乳动物神经的复杂性和实验室培养和 一种昆虫的基因操作：蟋蟀双斑蟋蟀。在板球大脑中，神经母细胞 学习和记忆所必需的神经干细胞。我们发现，被保护的 转录因子CREB在动物的学习和记忆中起着核心作用，它调节 分子组织者Oskar，这两个基因都是长期记忆所必需的。我们假设 Oskar和CREB引导神经母细胞适当的不对称分裂成神经元，这使得长时间 待建立的学期记忆。我们将通过追求三个互补性来检验这一假设 明确的目标。在目标1中，我们将确定Oskar是否调节成人神经母细胞不对称细胞 组织。我们将使用CRISPR/Cas9和RNAi来废除Oskar表达，并确定这是如何 应用原位杂交、免疫组织化学和共聚焦技术影响细胞不对称分裂 显微镜。在目标2中，我们将确定Oskar在Gryllus神经母细胞中的相互作用伙伴。至 为此，我们将评估已知基因的神经表达和长期记忆功能 在其他类型的细胞中与奥斯卡互动。我们还将采取不偏不倚的方法来确定相关的 Oskar通过使用单细胞RNA-seq来确定神经母细胞的完整转录组。 在目标3中，我们将确定CREB在调节神经母细胞分裂中的作用。我们将减少CREB 并研究CREB缺失如何影响神经母细胞的不对称细胞分裂。 这些实验的结果将阐明调节记忆的细胞机制 形成，这可能导致新的方法来改善记忆相关的疾病。

PROJECT SUMMARY In development and homeostasis, progenitor stem cells of critical organ systems often divide asymmetrically. Memory formation involves adult neurogenesis, wherein progenitor stem cells in the adult brain divide asymmetrically to produce nascent neurons. The ability to form and recall specific memories is indispensable to our survival. Patients with neurodegenerative diseases such as Alzheimer’s exhibit drastic disruptions in learning and memory. As such, elucidating the developmental and mechanistic underpinnings of memory formation is critical to identifying and preventing processes that lead to brain disease. Our long-term objective is to understand the molecular mechanisms that generate new neurons in adult brains. We have established a new model organism for tackling this problem, one that combines the neural complexity of a mammal with the ease of laboratory culture and genetic manipulation of an insect: the cricket Gryllus bimaculatus. In the cricket brain, neuroblasts are neural stem cells necessary for learning and memory. We have discovered that the conserved transcription factor CREB, which plays a central role in animal learning and memory, regulates the molecular organizer oskar, and that both genes are required for long term memory. We hypothesize that Oskar and CREB direct proper asymmetric division of neuroblasts into neurons, which allows long term memories to be established. We will test this hypothesis through pursuit of three complementary Specific Aims. In Aim 1, we will determine whether oskar regulates adult neuroblast asymmetric cell division. We will use CRISPR/Cas9 and RNAi to abrogate oskar expression and determine how this affects asymmetric cell division using in situ hybridization, immunohistochemistry, and confocal microscopy. In Aim 2, we will identify the interacting partners of Oskar within Gryllus neuroblasts. To this end, we will assess the neural expression and long-term memory function of genes known to interact with oskar in other cell types. We will also take an unbiased approach to identifying relevant oskar interactors by using single cell RNA-seq to determine the complete transcriptome of neuroblasts. In Aim 3, we will define the role of CREB in regulating neuroblast division. We will reduce CREB expression in the adult brain and examine how CREB loss affects neuroblast asymmetric cell division. The results of these experiments will shed light on the cellular mechanisms that regulate memory formation, which could lead to novel approaches to ameliorate memory-related diseases.