DEFINING THE ROLE OF CAMKII IN SYNAPTIC PLASTICITY

脊椎动物突触可塑性的一个有前途的和被广泛研究的例子 是长时程增强(LTP)，即持续性突触增强 在短暂的突触剧烈活动之后。蜂窝和 LTP背后的分子机制可能解释几个生理问题 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。这个 负责产生LTP的细胞信号已经被研究过了 广泛地。一种被认为在LTP中发挥重要作用的分子是 钙/钙调蛋白依赖的蛋白激酶II(CaMKII)。在这个项目中，我 将检验突触后CaMKII活性增加的假设 足以产生LTP。这个项目的具体目标是测试 这一假设回答了以下几个问题： 1.细胞内CaMKII活性酶的急性表达 突触后神经元模拟和阻断LTP？即，它是否增强了 传输和耗尽LTP过程？ 2.突触后突触中野生型CaMKII酶的急性表达 细胞从CaMKII已被抑制的小鼠脑片中拯救LTP 基因“被淘汰”了吗？ 这些问题将通过一种新的病毒感染技术来解决 这使得感兴趣的基因在靶向区域的快速表达 海马片。大量的数据显示了这种技术的有效性。 初步数据表明，一种结构性活性基因的表达 突触后海马片神经元中的CaMKII增强突触 传输并防止更多的LTP。拟议中的实验将结合 这一新方法与现代突触电生理检测相结合 变速箱。 我的实验室的长期目标是勾勒出 活动依赖的生化和生物物理机制 中枢神经系统中的突触可塑性。该项目将作为一个基础 找出LTP拼图中的核心部分。更广泛地说，我们会 继续开发适用于大范围信号的方法 中枢神经系统的信号转导问题。此外，这并不是不合理的 这样的病毒策略将很快用于中枢神经系统的基因治疗 病理学。继续发展这些将是很重要的 实验系统，以测试病毒感染和 突触传递和可塑性的重组表达。急性 重组产物在海马片中的表达提供了许多 优势，因为许多生理和病理过程 在这一准备过程中进行了仔细的研究。

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.