DEFINING THE ROLE OF CAMKII IN SYNAPTIC PLASTICITY

脊椎动物突触可塑性的一个有希望的和广泛研究的例子 是长时程增强（LTP）， 在短暂的强烈突触活动之后细胞和 LTP潜在的分子机制可以阐明几种生理学机制， 和病理过程，包括学习、记忆、发育 突触特异性、疼痛、神经元死亡、癫痫和痴呆。的 已经研究了负责产生LTP的细胞信号传导 广泛地。被认为在LTP中起重要作用的分子是 Ca++/钙调蛋白依赖性蛋白激酶II（CaMKII）。在这个项目中，我 将检验突触后CaMKII活性的增加 足以产生LTP。该项目的具体目标是测试 通过回答以下问题来验证这一假设： 1.急性表达的组成型活性CaMKII酶是否 突触后神经元模仿并阻断LTP？即，它是否增强 传输和使用LTP过程？ 2.突触后神经元中野生型CamKII酶的急性表达 细胞拯救LTP在从小鼠制备的切片中，其中CaMKII已被 基因上被“淘汰”了 这些问题将使用一种新的病毒感染技术来解决 其允许感兴趣的基因在细胞的靶向区域中的急性表达， 海马切片。大量的数据显示了这项技术的有效性 初步数据表明，组成型活性蛋白的表达 突触后海马脑片神经元中CaMK Ⅱ增强突触的作用 传输并防止更多的LTP。拟议的实验将联合收割机 这种新的方法与现代电生理学测定的突触 传输 我的实验室的广泛的长期目标是描绘 活动依赖性的生化和生物物理机制 突触可塑性的研究该项目将作为一个基础， 找出LTP难题的核心部分一般来说，我们将 继续开发适用于大范围信号的方法 中枢神经系统中的信号转导问题。此外， 这种病毒策略将很快用于中枢神经系统的基因治疗 病理学重要的是要继续发展这些 实验系统，以测试病毒感染的影响， 重组表达对突触传递和可塑性的影响。 急性 在海马切片中表达重组产物提供了许多 由于许多生理和病理过程 在这篇文章中，我们仔细研究了。

A promising and widely studied example of vertebrate synaptic plasticity is long-term potentiation (LTP), the persistent synaptic enhancement seen following a brief period of intense synaptic activity. The cellular and molecular mechanisms underlying LTP may elucidate several physiological and pathological processes, including learning, memory, developmental synapse specificity, pain, neuronal death, epilepsy and dementia. The cellular signaling responsible for generating LTP has been studied extensively. A molecule thought to play an important role in LTP is the Ca++/calmodulin-dependent protein kinase II (CaMKII). In this project I will test the hypothesis that an increase in postsynaptic CaMKII activity is sufficient to produce LTP. The specific aim of this project is to test this hypothesis by answering the following: 1. Does acute expression of a constitutively active CaMKII enzyme in postsynaptic neurons mimic and occlude LTP? i.e. does it enhance transmission and use up the LTP process? 2. Does acute expression of the wild type CamKII enzyme in postsynaptic cells rescue LTP in slices prepared from mice in which CaMKII has been genetically "knocked out"? These questions will be addressed using a novel viral infection technique that allows acute expression of a gene of interest in targeted regions of hippocampal slices. Extensive data shows the efficacy of this technique and preliminary data indicates that expression of a constitutively active CaMKII in postsynaptic hippocampal slice neurons enhances synaptic transmission and prevents more LTP. The proposed experiments will combine this new method with modern electrophysiological assays of synaptic transmission. The broad long-term objectives of my laboratory are to delineate the biochemical and biophysical mechanisms underlying activity-dependent synaptic plasticity in the CNS. This project will serve as a foundation by identifying a central piece in the puzzle of LTP. More generally we will continue to develop a methodology applicable to a large range of signal transduction problems in the CNS. Furthermore, it is not unreasonable that such viral strategies will soon be used in gene therapy for CNS pathologies. It will be important to continue to develop these experimental systems, to test the effect of viral infection and recombinant expression on synaptic transmission and plasticity. Acute expression of recombinant products in the hippocampal slice offers many advantages since numerous physiological and pathological processes have been carefully studied in this preparation.