Molecular mechanisms governing maintenance of neural identity

描述(由申请人提供)：准确的细胞身份是维持一个连贯的通信神经元网络所必需的。在人脑中，神经网络是以一种受控良好的方式构建的，然后经历多次强化和调制的迭代，从而形成一个能够进行成人认知的系统。这种改进在很大程度上发生在儿童和青春期，在与环境互动的背景下。在整个过程中，特定的细胞在网络中建立独特的身份；它们的角色取决于由早期发育程序定义的初始细胞类型，以及当它们作为一个整体整合到神经系统时发生的修改。如果神经元在适应周围发展的网络时不能保持其初始的、基本的特征，那么它在系统中的作用可能会被破坏。这项研究旨在研究神经元在不断变化的环境中保持其身份的关键方面的分子手段。由于对一个细胞的多个不确定的输入可能很难控制，它们的影响也可能很难跟踪，因此本研究利用了一个系统，其中刺激定义得很好，细胞身份的标记很容易跟踪。线虫体内的AWC嗅觉神经元检测到一组定义的挥发性化学物质，并可以通过一组特定的分子标记进行识别。本研究的目的是确定和表征在AWCs分化后，当神经元首次暴露于外部嗅觉刺激时，负责维持神经同一性的分子。具体地说，本研究旨在：(1)确定核蛋白NSY-7的作用机制，NSY-7是AWC神经元在分化后保持其某些特性所必需的；(2)表征NSY-7基因的表达和调控，以便更好地了解其功能；以及(3)确定NSY-7与AWC中负责感觉信号转导的分子通路之间的相互作用。对控制神经同一性维持的机制的研究可能有助于阐明某些精神障碍所涉及的因素，例如精神分裂症，这些疾病似乎部分受基因控制，但在青春期或青春期后首次显现。看似正常的大脑在发育后期未能获得稳定的原因在很大程度上仍未确定，但看似稳定的大脑偏离正常状态的疾病普遍存在。因此，阐明通常控制这一现象的基因及其在治疗和预防精神疾病方面的应用，将广泛有益于公众健康和社区。

DESCRIPTION (provided by applicant): Precise cellular identities are necessary to maintain a coherent network of communicating neurons. In the human brain, neural networks are constructed in a well-controlled manner and then subjected to multiple iterations of reinforcement and modulation, resulting in a system capable of adult cognition. Much of this refinement takes place during childhood and adolescence, in the context of interactions with the environment. Throughout this process, specific cells establish unique identities within the network; their roles are dependent both on the initial cell type, defined by an early developmental program, and on the modifications that occur as they become integrated into the nervous system as a whole. If a neuron cannot retain its initial, fundamental characteristics as it adapts itself to the network developing around it, its role in the system may be corrupted. This study aims to examine the molecular means by which a neuron maintains crucial aspects of its identity in a changing environment. Because multiple undefined inputs to a cell may be difficult to control and their effects may be difficult to track, this study makes use of a system in which stimuli are well defined, and markers of cell identity are easy to follow. The AWC olfactory neurons in the nematode C. elegans detect a defined set of volatile chemicals and can be identified by a specific set of molecular markers. The goal of this study is to identify and characterize molecules responsible for maintaining neural identity in the AWCs after differentiation, when the neurons are first exposed to external olfactory stimuli. Specifically, this study aims to: (1) determine the mechanism of action of the nuclear protein, NSY-7, which is required for one of the AWC neurons to retain aspects of its identity after differentiation; (2) characterize the expression and regulation of the nsy-7 gene in order to better understand its function, and (3) define interactions between nsy-7 and the molecular pathway responsible for sensory signal transduction in the AWCs. Examination of the mechanisms controlling maintenance of neural identity may serve to illuminate the factors involved in certain psychiatric disorders, such as schizophrenia, that appear to be partially under genetic control but that first manifest themselves at or after adolescence. The factors responsible for the failure of an apparently normal brain to attain stability late in development remain largely unidentified, but disorders in which an seemingly stable brain departs from its normal state are widespread. Elucidation of the genes that normally control this phenomenon, and their application in the treatment and prevention of psychiatric disease, would therefore be broadly beneficial to public health and to the community.