MORPHOCHEMISTRY OF CEREBELLAR BRAINSTEM NEURONS AND CIRCUITS

小脑脑干神经元和电路的形态化学

• 批准号: 6273631
• 负责人: DEAN E HILLMAN
• 金额: $ 29.91万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-12-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6273631
• 关键词: brain stem; calcineurin; calcium binding protein; calcium channel; calcium transporting ATPase; calmodulin; carbohydrate receptor; cell membrane; cerebellar Purkinje cell; cerebellum; endoplasmic reticulum; granule cell; immunoelectron microscopy; inositol phosphates; laboratory rat; neurons; potassium channel; synapses

The overall goal of this project is to define the morphological basis for the spatial and temporal properties of calcium signaling in cerebellar neurons. The proposed experiments will focus on P-type calcium channels, plasmalemmal calcium pumps, and calcium concentration management molecules. The hypotheses to be tested and specific aims fall into two categories: 1) For the P-type calcium channel signaling and management system we propose that: i) P-type calcium channels are localized at synaptic junctions on the dendritic tree and somata of Purkinje, granule, and cerebellar nuclear neurons and that this localization relates to neuronal integration and second messenger signaling. ii) In order to restrict calcium concentration levels, calcium pumps (ATPases) are distributed at punctate sites over the dendritic arbor of Purkinje cells with the highest concentrations occurring distally on dendrites and spines in close association with P channels. iii) P-type calcium channels and plasmalemmal calcium pumps are co-localized and associated with mobile and bound calcium-buffering molecules, such calmodulin and calcineurin, which further increase the [Ca2+]i regulation abilities of these neurons. 2) For the IP3 intracellular calcium signaling and management system we propose that the endoplasmic reticulum, in association with IP3 receptor-related calcium channels and smooth ER calcium pumps, form a framework which establishes functional microdomains of intracellular calcium signaling and management. The studies will be carried out in the cerebellum of the rat using immunocytochemical techniques at both the light and electron microscopic levels. Ultrastructural studies will take advantage of recent advances in the high resolution localization of protein macromolecules, improved methods we have developed to pre-treat tissue sections, and the recent generation of specific antibodies against the P channel. An understanding of the morphological basis of both the plasmalemmal and the endomembrane calcium concentration management systems, and the relationship between these systems in controlling the cytosolic calcium concentration and in providing a mechanism for extruding calcium from neurons are critical elements in understanding neuronal function.

这个项目的总体目标是确定的形态基础， 小脑钙信号的时空特性 神经元 拟议的实验将集中在P型钙通道， 质膜钙泵和钙浓度管理 分子。 待检验的假设和具体目标分为两类 类别：1）用于P型钙通道的信号传导和管理 系统，我们提出：i）P型钙通道定位于 树突树和浦肯野胞体上的突触连接，颗粒， 和小脑核神经元，这种定位与 神经元整合和第二信使信号传导。（二）为了 限制钙浓度水平，钙泵（ATP酶）是 分布在浦肯野细胞树枝状结构上的点状部位 浓度最高的出现在远端的树突和棘上 与P通道密切相关。iii）P-型钙通道和 质膜钙泵与移动的和 结合钙缓冲分子，如钙调蛋白和钙调神经磷酸酶， 进一步增强这些神经元的[Ca~（2+）] i调节能力。2)为 我们提出的IP3细胞内钙信号和管理系统 内质网与IP3受体相关， 钙通道和平滑的ER钙泵，形成一个框架， 建立细胞内钙信号传导的功能微区， 管理 研究将在大鼠小脑中进行 利用免疫细胞化学技术， 微观层面。 超微结构研究将利用最近的 蛋白质大分子的高分辨率定位的进展， 我们已经开发了改进的方法来预处理组织切片， 新一代针对P通道的特异性抗体。 一个 了解质膜和质膜的形态学基础 内膜钙浓度管理系统， 这些系统之间的关系在控制胞浆钙 浓度，并提供了一种机制， 神经元是理解神经元功能的关键要素。