Calcium Signaling in Astrocytes

描述（由申请人提供）：本申请涉及广泛的挑战领域（15）：转化科学和特定的挑战主题，15- NS-104：早期治疗发展。这项工作的主要目标是开发新的技术和理论手段来了解颞叶癫痫（TLE）的机制，并评估这种毁灭性疾病的新类型可能的治疗方法。利用现有的方法治疗TLE往往很困难，仅在美国每年就需要120亿美元的经济成本。拟议的工作在几个方面具有变革性。首先，这项工作的重点是胶质支持细胞（特别是星形胶质细胞）在TLE中的假定作用。尽管有令人信服的证据表明星形胶质细胞参与癫痫功能障碍，但这一证据尚未得到广泛接受，使得关注星形胶质细胞的方法未得到充分的重视和利用。其次，所提出的方法依赖于一种新的成像技术，称为靶向路径扫描（TPS），它可以同时记录多达100个细胞中的神经元和胶质钙瞬态，具有单细胞的空间分辨率和优异的时间分辨率。TPS方法允许提出的研究计划研究相互作用神经元和神经胶质网络中TLE的机制和假定治疗方法，具有时空分辨率，允许在细胞和网络水平上同时分析。拟议的研究有两个具体目的。目的1探讨了在受kainic酸（KA）模型的TLE动物的脑切片中星形细胞群钙瞬态的性质是否被改变。在潜伏期（诱导癫痫持续状态之后，自发发作之前）和自发发作开始之后的动物切片中，这些瞬态将被描述，并与年龄匹配的对照数据进行比较。需要研究的相关特性包括星形细胞网络的时间频率、大小和空间范围。目的2聚焦于星形细胞钙瞬态和附近神经元中峰驱动钙瞬态之间的相互作用。在这个目标中需要解决的具体问题包括：星形胶质细胞和神经元中的钙瞬变是否在空间和/或时间上相关？如果是这样，在给定区域中哪种细胞类型领先于另一种？已知的抗癫痫药物如何影响星形胶质细胞中的钙瞬态，神经元中的钙瞬态，以及两种细胞类型之间的潜在相互作用？最后，这项突破性的技术能否作为一种基于网络的检测方法，用于鉴定治疗药物耐药性癫痫的新型抗惊厥药物分子？拟议的项目是药理学家/癫痫学家和生物工程师之间的开创性努力，其重点和意图是可翻译的。这项工作的主要目标是发展新的理论和方法，这些理论和方法可能对发现新的药物治疗毁灭性的癫痫发作障碍，颞叶癫痫具有宝贵的价值。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (15): Translational Science and specific Challenge Topic, 15- NS-104: Early-Stage Therapy Development. The major goal of the proposed work is to develop novel technical and theoretical means to understand the mechanisms underlying temporal lobe epilepsy (TLE) and to assess new classes of possible treatments for this devastating disorder. TLE is often difficult to treat using currently available approaches and entails an economic cost of $12 billion dollars per year within the United States alone. The proposed work is transformative on several fronts. First, the work focuses on the putative role of glial support cells (specifically, astrocytes) in TLE. Although there is a convincing body of evidence that astrocytes are involved in epileptic dysfunction, this evidence has not yet gained wide acceptance, leaving approaches that focus on astrocytes underappreciated and underutilized. Second, the proposed approach depends on a novel imaging technique, called targeted path scanning (TPS), which allows recordings of neuronal and glial calcium transients in up to 100 cells simultaneously, with single-cell spatial resolution and excellent temporal resolution. The TPS approach allows the proposed research program to study mechanisms and putative treatments of TLE in interacting neuronal and glial networks, with spatiotemporal resolution that permits simultaneous analysis at both the cellular and network levels. The proposed study has two specific aims. Aim 1 addresses whether the properties of astrocytic population calcium transients are altered in brain slices derived from animals that have been subjected to the kainic acid (KA) model of TLE. These transients will be characterized, and compared with data from age-matched controls, in slices from animals during both the latent period (after induction of status epilepticus but before spontaneous seizures) and after spontaneous seizures have begun. Relevant properties to be studied include temporal frequency, magnitude, and spatial extent throughout the astrocytic network. Aim 2 focuses on interactions between astrocytic calcium transients and spike-driven calcium transients in nearby neurons. Specific questions to be addressed in this aim include: Are calcium transients in astrocytes and neurons spatially and/or temporally correlated? If so, which cell type in a given area leads the other? How do known anti-epileptic drugs affect calcium transients in astrocytes, calcium transients in neurons, and the potential interactions between the two cell types? Finally, can this ground-breaking technology be used as a network- based assay for the identification of novel anticonvulsant molecules for the treatment of pharmacoresistant epilepsy? The proposed project-a pioneering effort between a pharmacologist/epileptologist and a bioengineer-is translational in its focus and intent. The major goal of the proposed work is to develop new theories and approaches that could be invaluable in discovering new pharmacological treatments for the devastating seizure disorder, temporal lobe epilepsy. PUBLIC HEALTH RELEVANCE: Temporal lobe epilepsy is a seizure disorder with devastating effects, particularly in the large number of patients for whom current treatments are ineffective. The purpose of the proposed work is to use ground- breaking imaging technology to study this disease in interacting networks of both nerve cells and glial metabolic support cells. A likely outcome of the proposed work will be entirely new ways to assess potential pharmacological therapies for epilepsy.