INTRACELLULAR SIGNALS FOR LONG TERM SYNAPTIC DEPRESSION

平行纤维（PF）和攀爬纤维（CF）的同时活动 神经突触支配小脑浦肯野细胞引起一个长期的 在PF突触处的传递抑制（LTD）。这种LTD是一种 突触可塑性可能是某些学习形式的基础， 在小脑中，被广泛研究作为一种实验上易于处理的 突触可塑性的例子。这件事的总目标是 项目是了解发生在突触后的分子事件， 浦肯野细胞产生有限公司的具体工作重点是研究 细胞内第二信使（如IP 3和Ca离子）在细胞内的作用 诱导LTD，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。拟议的实验 联合收割机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从惰性的“笼状”分子中释放将是一种有效的方法。 用来迅速提高这些信使的浓度， 浦肯野细胞的小区域。同时使用高速 激光共聚焦扫描显微镜将允许测量 这些操作的后果对钙浓度内 浦肯野细胞和膜片钳测量将确定是否这些 信使引起LTD或PF突触传递。这些实验将 定义IP3和Ca在LTD中的作用。 谷氨酸盐也将首次定义， 浦肯野细胞谷氨酸受体在有限责任公司。这一信息将 提供LTD最终表达的分子描述， 关于第二信使途径与谷氨酸耦合的进一步线索 受体。虽然这项工作主要是基础研究， 对神经元和突触的基本信号过程有了新的认识， 将有助于理解这些进程在 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.