Dynamic Chemical Regulation of Voltage-gated Sodium Channels

电压门控钠通道(VGSCs)对动作电位的产生至关重要。电压的调节- 门控离子通道功能是调节神经元信号和脑功能的重要途径， G蛋白偶联受体(GPCRs)是内源性信号转导机制的重要组成部分 这是通过它发生的。然而，与其他离子通道不同，VGSCs被认为是相对 对GPCR信号的调节不敏感。我们最近发现了一种途径，它受 已知与GPCRCB1(大麻素受体)相互作用的药物。这条途径广泛存在，存在于 绝大多数新皮质神经元，并且足够强大，足以完全可逆地阻断VGSC电流 当最大限度地刺激时。这种新颖的、动态的信号通路被定位为实质上调制 神经元兴奋性和脑功能。对潜在机制的详细了解对以下方面至关重要 了解它的诸多影响。这些初步发现可能会从根本上改变我们对 内源性大麻素的作用机制。这项提案的目标是确定如何 内源性大麻素对VGSCs有调节作用。我们将通过使用PATCH研究VGSC的功能来完成这项任务- 急性分离后急性新皮质脑片中神经元的钳制方法和活细胞成像 在初级文化中。我们将采用老鼠模型。我们非常适合执行这个项目，因为我们的 初步数据和专业知识。这些具体目标的成功完成将成为该机制的特征 通过这一新途径抑制钠通道的作用，并表征了一种新的机制 内源性大麻素可以影响神经可塑性。我们的理论基础是，识别和表征一个 新颖而流行的受体(S)及其下游途径将有助于我们理解流行的和 潜在强大的神经生物信号通路。对该途径的阐明将提供详细的 一种可能与多种疾病相关的新药靶点的表征 不平衡的兴奋性。

Voltage-gated sodium channels (VGSCs) are essential for action potential generation. Regulation of voltage- gated ion channel function is an important pathway by which neuronal signaling and brain function is regulated, and G-protein coupled receptors (GPCRs) form a major element of the endogenous transduction mechanisms by which this occurs. However, unlike other ion channels, VGSCs have been believed to be relatively insensitive to modulation by GPCR signaling. We have recently identified a pathway that is modulated by agents known to interact with the GPCR CB1 (cannabinoid receptor). This pathway is widespread, present in the vast majority of neocortical neurons, and strong enough to completely and reversibly block VGSC currents when maximally stimulated. This novel, dynamic signaling pathway is positioned to substantially modulate neuronal excitability and brain function. Detailed knowledge about the underlying mechanisms is crucial to understand its many effects. These preliminary findings may fundamentally change our understanding of the mechanism of action of endocannabinoids. The objectives of this proposal are to determine how endocannabinoids regulate VGSCs. We will complete this undertaking by studying VGSC function using patch- clamp methods and live cell imaging in neurons in acute neocortical brain slices, following acute isolation, and in primary cultures. We will employ mouse models. We are ideally suited to perform this project because of our preliminary data and expertise. Successful completion of these specific aims will characterize the mechanism of action of inhibition of sodium channels by this novel pathway and characterize a new mechanism by which endocannabinoids can affect neuroplasticity. Our rationale is that the identification and characterization of a novel and prevalent receptor(s) and downstream pathway will facilitate our understanding of a prevalent and potentially powerful neurobiological signaling pathway. Elucidation of the pathway will provide a detailed characterization of a new drug target that may be relevant to a wide range of diseases characterized by unbalanced excitability.