INTRACELLULAR SIGNALS FOR LONG TERM SYNAPTIC DEPRESSION

平行纤维(PF)和攀升纤维(CF)中的同时活动 支配小脑浦肯野细胞的突触导致长时间的 抑制(LTD)在PF突触的传递。本有限公司是一种 突触可塑性，可能是某些形式的学习的基础 在小脑中，被广泛研究为一种实验上易驯服的 长时间突触可塑性的例子。这样做的总体目标是 项目是了解突触后发生的分子事件 浦肯野细胞生产有限公司。这项工作的具体重点是研究 细胞内第二信使，如IP3和钙离子在细胞内的作用 并了解这些信使如何导致持久的 突触后谷氨酸受体的变化。拟议中的实验 结合电学和光学方法来研究这些信号通路。 光诱导的Ca和IP3从惰性“笼子”分子中租借 用来非常迅速地提高这些信使的浓度 浦肯野细胞的小区域。同时使用高速列车 共聚焦激光扫描显微镜将允许测量 这些操作对土壤中钙浓度的影响 浦肯野细胞和膜片钳的测量将决定这些 信使引起LTD或PF突触传递。这样的实验将 明确IP3和钙在LTD中的作用。局部光致释放 谷氨酸也将第一次定义发生在 浦肯野细胞谷氨酸受体。此信息将 提供LTD最终表达的分子描述，并给出 第二信使途径与谷氨酸偶联的进一步线索 感受器。虽然这项工作主要是基础研究，但它将产生 对神经元和突触的基本信号过程的新见解 将有助于理解这些过程在 由神经元缺陷引起的各种神经系统疾病 发信号。

Simultaneous activity in the parallel fiber (PF) and climbing fiber (CF) synapses innervating cerebellar Purkinje cells causes a long-lasting depression (LTD) of transmission at the PF synapse. This LTD is a form of synaptic plasticity that may underlie certain forms of learning that occur in the cerebellum and is widely studied as an experimentally tractable example of long-lasting synaptic plasticity. The general goal of this project is to understand the molecular events that occur in postsynaptic Purkinje cells to produce LTD. The specific focus of the work is to study the roles of intracellular second messengers, such as IP3 and Ca ions, in inducing LTD and to understand how such messengers cause long-lasting changes in postsynaptic glutamate receptors. The proposed experiments combine electrical and optical methods to study these signaling pathways. Light-induced lease of Ca and IP3 from inert "caged" molecules will be used to elevate the concentration of these messengers very rapidly within small regions of the Purkinje cell. Simultaneous use of a high-speed confocal laser-scanning microscope will permit measurement of the consequences of these manipulations upon Ca concentration within the Purkinje cell and patch-clamp measurements will determine whether these messengers cause a LTD or PF synaptic transmission. Such experiments will define the roles of IP3 and Ca in LTD. Localized light-induced release of glutamate will also define, for the first time, the changes that occur in Purkinje cell glutamate receptors during LTD. This information will provide a molecular description of the final expression of LTD and give further clues about the coupling of second messenger pathways to glutamate receptors. Although this work is primarily basic research, it will yield new insights into basic signaling processes of neurons and synapses and will be useful for understanding the roles of such processes in the various neurological diseases that arise from defective neuronal signaling.