LTD and spatio-temporal dynamics of IP_3 within cerebellar Purkinje cells

LTD 和小脑浦肯野细胞内 IP_3 的时空动态

• 批准号: 15390079
• 负责人: HIROSE Kenzo
• 金额: $ 9.73万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15390079/
• 关键词: cerebellum; Purkinje cell; Inositol trisphosphate; calcium; LTD

Long-term depression (LTD) at parallel fiber-Pukinje cell synapse is an elemental electrophysiological process underlying cerebellar motor learning. Although the understanding the mechanism of LTD is an important issue to be addressed, details of the molecular mechanism remain to be clarified. In this study, we hypothesized that the intracellular dynamics of inositol 1,4,5-trisphosphate (IP_3) within Purkinje cells regulates induction of LTD, and addressed the issue. We analyzed how presynaptic stimulations impact the IP_3 dynamics in Purkinje cells using GFP-PHD which we have previously developed for visualization of spatio-temporal dynamics of intracellular IP_3. Purkinje cells in cerebellar slice preparation transduced with GFP-PHD were imaged under the two-photon laser scanning microscope. With this configuration, allowing us to visualize changes in the concentration of IP_3 in the fine dendrites of Pukenje cells, we for the first time succeeded in direct observation of the raise in the concentration of IP_3 in response to parallel fiber stimulation. There are two types of glutamate receptors : ionotropic (iGluR) and metabotropic (mGluR) glutamate receptors. We discovered that not only mGluR but also iGluR participates in the production of IP_3 evoked by parallel fiber input. Taken together with the results of the additional experiments, we concluded that mGluR and iGluR, cooperatively work for IP_3 production through the G-protein and calcium influx dependent mechanisms, respectively. Theses research results thus greatly advances the understating of the spatio-temporal role of IP_3 in the regulation of LTD. We should also note that we have developed several new technologies including a method for RNAi library construction and a method for highly efficient knock down of IP_3 receptors in the course of this research. These technologies will greatly contribute to understanding of molecular mechanisms of LTD, as well as to the research in the related fields.

平行纤维普金野细胞突触的长期抑制（LTD）是小脑运动学习的基本电生理过程。尽管理解LTD的机制是一个有待解决的重要问题，但分子机制的细节仍有待阐明。在这项研究中，我们假设浦肯野细胞内肌醇 1,4,5-三磷酸 (IP_3) 的细胞内动力学调节 LTD 的诱导，并解决了这个问题。我们使用 GFP-PHD 分析了突触前刺激如何影响浦肯野细胞中的 IP_3 动态，我们之前开发了 GFP-PHD，用于可视化细胞内 IP_3 的时空动态。用 GFP-PHD 转导的小脑切片制剂中的浦肯野细胞在双光子激光扫描显微镜下成像。通过这种配置，我们能够可视化 Pukenje 细胞细树突中 IP_3 浓度的变化，我们首次成功地直接观察到平行纤维刺激响应中 IP_3 浓度的升高。谷氨酸受体有两种类型：离子型 (iGluR) 和代谢型 (mGluR) 谷氨酸受体。我们发现不仅 mGluR 而且 iGluR 也参与平行纤维输入诱发的 IP_3 的产生。结合其他实验的结果，我们得出结论，mGluR 和 iGluR 分别通过 G 蛋白和钙内流依赖性机制合作生产 IP_3。这些研究成果极大地推进了对IP_3在LTD调控中时空作用的认识。我们还应该注意到，在本研究过程中，我们开发了多项新技术，包括RNAi文库构建方法和高效敲低IP_3受体的方法。这些技术将极大地有助于理解LTD分子机制以及相关领域的研究。

项目成果

Cross talk between metabotropic and ionotropic glutamate receptor-mediated signaling in parallel fiber-induced inositol 1,4,5-trisphosphate production in cerebellar Purkinje cells

• DOI: 10.1523/jneurosci.1829-04.2004
• 发表时间: 2004-10-27
• 期刊: JOURNAL OF NEUROSCIENCE
• 影响因子: 5.3
• 作者: Okubo, Y;Kakizawa, S;Iino, M
• 通讯作者: Iino, M

Glucose metabolism and glutamate analog acutely alkalinize pH of insulin secretory vesicles of pancreatic β-cells.

葡萄糖代谢和谷氨酸类似物急剧碱化胰腺 β 细胞胰岛素分泌囊泡的 pH 值。

• 发表时间: 2003
• 期刊: Am.J Physiol.Endocrinol.Metab. 285
• 作者: Eto;K.;Yamashita;T.;Hirose;K.;Tsubamoto;Y.;Ainscow;EK.;Rutter;G.A.;Kimura;S.;Noda;M.;Iino;M.;Kadowaki;T.
• 通讯作者: T.

Spatiotemporal laser inactivation of inositol 1,4,5-trisphosphate receptors using synthetic small-molecule probes

• DOI: 10.1016/s1074-5521(03)00122-4
• 发表时间: 2003-06-01
• 期刊: CHEMISTRY & BIOLOGY
• 作者: Inoue, T;Kikuchi, K;Nagano, T
• 通讯作者: Nagano, T

Glucose metabolism and glutamate analog acutely alkalinize pH of insulin secretory vesicles of pancreatic beta-cells.

葡萄糖代谢和谷氨酸类似物使胰腺 β 细胞的胰岛素分泌囊泡的 pH 值急剧碱化。

• 发表时间: 2003
• 期刊: Am.J.Physiol.Endocrinol.Metab. 285
• 作者: Eto;K 他
• 通讯作者: K 他

冨田太一郎 他: "FAT functions as working memory of Ca^<2+> signals in decoding Ca^<2+> oscillation"EMBO.J.. 22. 3825-3832 (2003)

Taichiro Tomita 等：“FAT 在解码 Ca^<2+> 振荡中充当 Ca^<2+> 信号的工作存储器”EMBO.J.. 22. 3825-3832 (2003)