Photochemical regulation of calcium in cell physiology

描述(申请人提供)：钙是哺乳动物细胞中最重要的单一信使分子。其浓度的波动控制着从基因表达到伤口愈合的无数过程。这项提议的目标是化学合成基于光化学的探针，用于控制活体动物的钙浓度。新的激光和显微镜技术现在可以在体内对单个小突触的结构进行成像。我们希望使用这项技术(双光子显微镜)不仅仅是细胞功能的被动观察者。我们建议制造化学探针，使我们能够积极干预体内单个细胞的钙动力学。为了做到这一点，我们将利用我们最近制造的一个新的发色团(称为“NDBF”)，它对双光子激发特别敏感。我们将开发通过双光子光解以光化学方式释放的IPS或钙受体激动剂的功能性惰性(或笼子)衍生物。这些新的探针将与其他科学家合作，研究基本的钙调节过程如何在单个突触水平上编码记忆。它们还将与钙的双光子成像结合使用，以探索癫痫和阿尔茨海默病等疾病状态的小鼠模型以及尼古丁成瘾期间钙信号的动力学。钙信号明显受到这些状态的干扰。我们计划开发的光化学探针将使我们能够第一次检查活动物的这些变化。

DESCRIPTION (provided by applicant): Calcium is the single most important messenger molecule in mammalian cells. Fluctuations in its concentration control a myriad of processes from gene expression to wound healing. The goal of this proposal is the chemical synthesis of photochemically based probes that will be used to control calcium concentration in living animals. New laser and microscope technologies now permit the imaging of structures as small single synapses in vivo. We wish to use this technology (the two-photon microscope) to be more than passive observers of cell function. We propose to make chemical probes that will allow us to actively intervene in the calcium dynamics of individual cells in vivo. To do this we will take advantage of a new chromophore we have recently made (called "NDBF"), that is uniquely sensitive to two-photon excitation. We will develop functionally inert (or "caged") derivatives of IPS or calcium receptor agonists that are photochemically liberated by two-photon photolysis. These new probes will be used in collaboration with other scientists to study how basic calcium-regulated processes encode memory at the level of single synapses. They will also be used, in concert with two-photon imaging of calcium, to probe the dynamics of calcium signaling in mouse models of disease states such epilepsy and Alzheimer's, as well as during nicotine addiction. Calcium signaling is significantly perturbed by these states. The photochemical probes we propose to develop will enable us to examine these changes in living animals for the first time.