Heterologous expression of an invertebrate sodium channel for neuronal activation

描述（由申请人提供）：了解单个神经元亚型如何促进神经网络功能对于理解神经系统如何功能以及理解特定神经元亚型的功能障碍如何导致神经和精神疾病至关重要。然而，目前用于激活完整神经组织中的神经元或神经元过程的方法不允许对单个亚型神经元进行不加区分的激发。该提案计划开发一种技术，通过在特定类型的神经元中表达能够在激活蛋白受到刺激时仅使这些神经元去极化的蛋白质基因，从而允许选择性地激活单个神经元亚型。我们将使用的激活蛋白是蜗牛FMRFamide配体门控钠通道（FaNaC）。FaNaC是理想的，因为它在哺乳动物神经系统中没有发现，因此只允许选择性激活其表达的神经元。为了改进这项技术，我们将尝试合成一种光敏化合物，可以以毫秒级的精度激活表达FaNaC的神经元。此外，我们将使用快速激活FaNaC或其他异源表达蛋白来研究海马CA1中特定类型的抑制性中间神经元如何被特定类型的周围神经元控制。由于抑制性中间神经元在癫痫、焦虑、精神分裂症和痉挛等中枢神经系统疾病中发挥作用，因此从这些研究中获得的信息将有助于了解抑制性中间神经元功能障碍如何导致中枢神经系统功能异常。公共卫生相关性：本研究提出开发一种基于基因的工具，该工具将允许激活完整神经组织中特定类型的神经元。我们计划使用这个工具来检查抑制性中间神经元在控制海马网络活动中的功能。这些研究将为我们提供一个模型，以了解特定神经元在正常脑功能以及精神和神经疾病中的作用。

DESCRIPTION (provided by applicant): Understanding how individual neuronal subtypes contribute to neural network function is vital to understanding how the nervous system functions and in understanding how dysfunction of specific neuronal subtypes contributes to neurological and psychiatric diseases. However, current methods used to activate neurons or neuronal processes in intact nervous tissue have not permitted the indiscriminate excitation of an individual subtype of neuron. This proposal plans to develop a technique that will permit the selective activation of individual subtypes of neurons by expressing in specific types of neurons genes of proteins that are capable of depolarizing only those neurons when the activator protein is stimulated. The activator protein we will use is the snail FMRFamide ligand-gated sodium channel (FaNaC). FaNaC is ideal because it is not found in the mammalian nervous system thereby allowing selective activation of only the neurons in which it has been expressed. To improve this technique, we will attempt to synthesize a light-sensitive compound that can activate FaNaC expressing neurons with millisecond precision. Furthermore, we will use rapid activation of FaNaC or other heterologously-expressed proteins to study how specific types of inhibitory interneurons in hippocampal CA1 are controlled by specific types of surrounding neurons. Because inhibitory interneurons have roles in CNS diseases such as epilepsy, anxiety, schizophrenia and spasm, information obtained from these studies will be relevant to understanding how inhibitory interneuron dysfunction may contribute to abnormal CNS function. PUBLIC HEALTH RELEVANCE: This study proposes to develop a gene based tool that will permit the activation of specific types of neurons in intact nervous tissue. We plan to use this tool to examine the function of inhibitory interneurons in controlling hippocampal network activity. These studies will provide us with a model to understand the role of specific neurons in normal brain function and in psychiatric and neurological disorders.