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)：翻译科学和具体的挑战主题，15-NS-104：早期治疗发展。拟议工作的主要目标是发展新的技术和理论手段，以了解颞叶癫痫(TLE)的潜在机制，并评估这种破坏性疾病的新的可能治疗类别。TLE通常很难用目前可用的方法治疗，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，这项工作侧重于神经胶质支持细胞(具体地说，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与癫痫功能障碍有关，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得不到充分重视和利用。其次，所提出的方法依赖于一种名为靶向路径扫描(TPS)的新成像技术，该技术可以同时记录多达100个细胞的神经元和神经胶质钙瞬变，具有单细胞的空间分辨率和出色的时间分辨率。TPS方法允许拟议的研究计划在相互作用的神经元和神经胶质网络中研究TLE的机制和假定的治疗方法，具有时空分辨率，允许在细胞和网络水平上同时进行分析。这项拟议的研究有两个具体目标。目的1研究TLE动物脑片中星形胶质细胞钙瞬变的性质是否发生改变。这些暂态将在潜伏期(在癫痫持续状态诱导之后但在自发发作之前)和在自发发作开始之后的动物切片中进行表征，并与年龄匹配的对照组的数据进行比较。需要研究的相关属性包括整个星形细胞网络的时间频率、幅度和空间范围。目的2重点研究星形胶质细胞钙瞬变和附近神经元尖峰驱动的钙瞬变之间的相互作用。在这一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在空间和/或时间上是否相关？如果是这样的话，在给定的区域中，哪种类型的细胞领先于另一种细胞类型？已知的抗癫痫药物如何影响星形胶质细胞的钙瞬变、神经元的钙瞬变以及两种细胞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分析来鉴定用于治疗耐药癫痫的新的抗癫痫分子？拟议的项目--一名药理学家/癫痫专家和一名生物工程师之间的开创性努力--在重点和意图上是翻译的。这项拟议工作的主要目标是开发新的理论和方法，这些理论和方法可能对发现治疗破坏性癫痫--颞叶癫痫--的新药物疗法具有非常宝贵的价值。 公共卫生相关性：颞叶癫痫是一种癫痫发作障碍，具有毁灭性的影响，特别是在目前治疗无效的大量患者中。这项拟议工作的目的是使用开创性的成像技术在神经细胞和神经胶质代谢支持细胞的相互作用网络中研究这种疾病。这项拟议工作的一个可能结果将是评估癫痫潜在药物疗法的全新方法。

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.