CRCNS: PKMzeta-Dependent Protein Synthesis Maintains Synaptic Plasticity

CRCNS：PKMzeta 依赖性蛋白质合成维持突触可塑性

• 批准号: 8840208
• 负责人: HAREL Zeev SHOUVAL
• 金额: $ 28.32万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8840208
• 关键词: Accounting; Address; Age; Back; Behavioral; Binding; Biochemical; Biological Sciences; Biology; Brain; Calcium; Calmodulin; Chemosensitization; Clinical; Collaborations; Communities; Computational Biology; Computer Simulation; Dependence; Diffuse; Diffusion; Disadvantaged; Drug abuse; Education; Feedback; Goals; Grant; High School Student; Hippocampus (Brain); Hour; Housing; Human; In Vitro; Information Storage; Instruction; Kinetics; Knowledge; Learning; Life; Long-Term Potentiation; Maintenance; Mediating; Memory; Mental disorders; Mentors; Methodology; Modeling; Molecular; Molecular Conformation; Neurosciences; New York; Pathway interactions; Pharmaceutical Preparations; Phase; Phosphorylation; Phosphotransferases; Play; Post-Traumatic Stress Disorders; Property; Protein Biosynthesis; Protein Isoforms; Protein Kinase; Protein Kinase C; Protein Synthesis Inhibitors; Proteins; Qualifying; Recording of previous events; Regulation; Research; Rice; Role; Science; Scientist; Site; Slice; Solid; Solutions; Students; Synapses; Synaptic Transmission; Synaptic plasticity; System; Techniques; Testing; Theoretical model; Time; Toxic effect; Training; Translations; Work; Youth; abstracting; addiction; base; biophysical model; drug reward; drug seeking behavior; experience; in vivo; inhibitor/antagonist; interest; link protein; long term memory; mathematical model; nervous system disorder; neuronal circuitry; novel; outreach; painful neuropathy; programs; protein degradation; research study; response; simulation; theories

DESCRIPTION (provided by applicant): We all have memories that date back to our youth; we remember the house we lived in at age 4; we remember a favorite schoolteacher. The mechanism for storing these memories is believed to be the long-term plasticity of synaptic connections within specific neuronal circuits. However, this putative cellular basis of memory relies on proteins that typically have lifetimes far shorter than the memory. Here exactly lies a fundamental problem of long-term memory and synaptic plasticity: How can memories be stored for a human lifetime on the basis of proteins that are continuously degrading? Recently, it was shown that the brain-specific PKC isoform, protein kinase Mζ(PKMζ), plays a unique role in maintaining both late long-term potentiation (L-LTP) of synapses and long-term memory. This crucial observation, however, does not explain how PKMζcan overcome the natural degrading effect of protein turnover and diffusion. The central hypothesis of this proposal is that PKMζ, through its control of its own synthesis, can form a bi-stable system, which can account for the maintenance of synapse specific long-term plasticity and memory. Here we propose to mathematically formulate this hypothesis within a biophysical model, and to analyze this model so as to propose testable experimental predictions. We then will directly test these predictions on PKMζ-mediated persistent synaptic potentiation, using novel techniques tailored for testing the theory. Intellectual Merit: The finding that PKMζ is both necessary and sufficient for the maintenance of synaptic plasticity and long-term memory has fundamentally changed the field of learning and memory, but much needs to be learned about the mechanisms that can actually accomplish the persistence of long-term plasticity and memory. This proposal addresses these questions using a combined theoretical and experimental approach. Such a theory in which bi-stability depends on regulation of translation is novel not only for neuroscience but also for biology in general. Our collaboration is uniquely qualified to carry out the proposed work because the Shouval lab has ample experience in modeling synaptic plasticity in collaboration with experimental groups, and the Sacktor lab has pioneered the science of PKM??and has ample experience with the proposed techniques. The experimental techniques include two new methodologies necessary for testing the predictions. First, we propose to test the model's predictions on protein translation in L-LTP, not by general protein synthesis inhibitors that may have issues of toxicity and indirect effects, but by use of antisense oligodeoxynucleotides directed to the translation start site of PKMζmRNA to specifically block PKMζ synthesis in induction and maintenance. Second, because PKMζ-mediated potentiation is both highly stable and yet rapidly reversible, we will use a fast-flow hippocampal slice chamber optimized for the study of the maintenance of L-LTP to test key predictions of the model. The proposed stochastic simulations of translation-dependent bi-stability are also novel in computational biology. Broader Impact: As the first demonstrated molecular mechanism of experience-dependent, long-term information storage in the brain, PKMζ has significant clinical implications, and within the last year has been shown to contribute to in the biology of a variety of neurological and psychiatric diseases, including post-traumatic stress disorder, central neuropathic pain, and drug abuse. In order to assist the rapidly growing interest in PKMζ in many labs, we will make our model accessible to the larger community, allowing for other scientists to test, modify, and incorporate their findings into the model, thus accelerating the pace of scientific discovery. Because an important goal for NSF is to integrate research and education, we will train a diverse pool of students. Our labs already train undergraduates, the Shouval lab takes undergraduates each summer through an REU program (PI S. Cox, Rice), and a UT system grant (PI H. Shouval), and local undergraduates throughout the year, and the Sacktor lab has had a long history of mentoring local disadvantaged high school students (e.g., through the Intel program). Both labs are dedicated to public outreach; for example, an article on PKMζ and memory was on the front page of The New York Times. We are eager to extend this type of outreach to the domain of the interaction between theory and experiment in biological sciences.

描述(申请人提供)：我们都有可以追溯到年轻时的记忆；我们记得我们4岁时住过的房子；我们记得一位最喜欢的老师。储存这些记忆的机制被认为是特定神经元回路中突触连接的长期可塑性。然而，这种假定的记忆细胞基础依赖于蛋白质，这些蛋白质的寿命通常远远短于记忆。这正是长期记忆和突触可塑性的一个根本问题：如何在不断降解的蛋白质的基础上将记忆储存到人类的一生？最近的研究表明，脑特有的蛋白激酶Mζ(PKMζ)在维持突触的晚期长时程增强(LTP)和长时记忆中起着独特的作用。然而，这一关键的观察结果并没有解释PKMζ如何克服蛋白质周转和扩散的自然降解效应。该方案的中心假设是，PKMζ通过控制自身的合成，可以形成一个双稳定系统，该系统可以解释突触特定的长期可塑性和记忆的维持。在这里，我们建议在生物物理模型中对这一假设进行数学表述，并对该模型进行分析，以提出可验证的实验预测。然后，我们将使用为测试该理论量身定做的新技术，直接测试这些关于PKMζ介导的持久突触增强的预测。智力价值：PKMζ是维持突触可塑性和长期记忆的必要条件和充分条件，这一发现从根本上改变了学习和记忆领域，但对于真正实现长期可塑性和记忆持久性的机制，仍有许多需要了解。本提案采用理论和实验相结合的方法解决这些问题。这种双稳定依赖于翻译调节的理论不仅对神经科学，而且对整个生物学都是新颖的。我们的合作是唯一有资格执行拟议工作的，因为Shouval实验室在与实验小组合作建模突触可塑性方面拥有丰富的经验，而Sacktor实验室是PKM科学的先驱，并在拟议的技术方面拥有丰富的经验。实验技术包括检验预测所必需的两种新方法。首先，我们不是用可能存在毒性和间接作用的一般蛋白质合成抑制剂来验证该模型对L-LTP中蛋白质翻译的预测，而是通过使用针对ζζ翻译起始点的反义寡核苷酸来特异性地阻断PKM PKM mRNA的诱导和维持合成。其次，由于PKMζ介导的增强作用既高度稳定又快速可逆，我们将使用为研究L-LTP的维护而优化的快速海马片室来检验该模型的关键预测。所提出的平移相关双稳性的随机模拟在计算生物学中也是新颖的。更广泛的影响：作为第一个被证明在大脑中依赖经验的长期信息存储的分子机制，PKMζ具有重要的临床意义，在过去的一年中，已被证明在多种神经和精神疾病的生物学中起到了作用，包括创伤后应激障碍、中枢神经性疼痛和药物滥用。为了帮助许多实验室对PKMζ迅速增长的兴趣，我们将使我们的模型可供更大的社区访问，允许其他科学家测试、修改并将他们的发现纳入模型，从而加快科学发现的步伐。由于NSF的一个重要目标是将研究与教育相结合，我们将培养一批多样化的学生。我们的实验室已经培训了本科生，Shouval实验室每年夏天通过REU计划(Pi S.Cox，莱斯)和德克萨斯大学系统资助(Pi H.Shouval)招收本科生，而Sacktor实验室则全年招收当地本科生，Sacktor实验室在指导当地弱势高中生方面有着悠久的历史(例如，通过Intel计划)。这两个实验室都致力于公共宣传；例如，《纽约时报》的头版刊登了一篇关于PKMζ和Memory的文章。我们渴望将这种类型的扩展扩展到生物科学中理论和实验之间的相互作用领域。