TRPC-mediated control of anxiety

TRPC 介导的焦虑控制

• 批准号: 9240488
• 负责人: VADIM BOLSHAKOV
• 金额: $ 45.44万
• 依托单位: MCLEAN HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9240488
• 关键词: Ablation; Address; Affect; Amygdaloid structure; Anti-Anxiety Agents; Anxiety; Anxiety Disorders; Area; Automobile Driving; Aversive Stimulus; Beds; Behavioral; Biological Neural Networks; Biophysics; Brain; Cell Nucleus; Cells; Cholecystokinin B Receptor; Coupled; Development; Electrophysiology (science); Equilibrium; Exhibits; Fiber; Fright; Genes; Genetic; Goals; Interneurons; Knock-out; Knockout Mice; Knowledge; Lateral; Lead; LoxP-flanked allele; Mediating; Metabotropic Glutamate Receptors; Mus; Mutant Strains Mice; Neurons; Output; Pattern; Phobias; Process; Property; Proteins; Publishing; Regulation; Role; Signal Transduction; Slice; Specificity; Structure of terminal stria nuclei of preoptic region; Synapses; Synaptic Transmission; System; TRP channel; Translating; Whole-Cell Recordings; anxiety spectrum disorders; anxiety states; anxiety treatment; anxiety-like behavior; anxious; behavioral outcome; behavioral response; biophysical properties; experimental study; feeding; functional outcomes; generalized anxiety; link protein; member; neural circuit; neuronal circuitry; novel therapeutics; optogenetics; patch clamp; public health relevance; receptor; relating to nervous system; response; synaptic function; tool

 DESCRIPTION (provided by applicant): The synaptic, neuronal and neural network mechanisms driving anxiety-like behaviors are not completely understood. Transient Receptor Potential channels (TRPC), belonging to the TRPC1/4/5 subfamily, are abundant in the brain areas implicated in control of innate fear responses, including the amygdala and the bed nucleus of the stria terminalis (BNST). Consistent with this expression pattern, we found recently that specific TRPC subunits belonging to this subfamily may contribute to anxiety mechanisms, possibly modulating the signal flow within specific neural circuits in the brain through activation of Gaq/11 protein-coupled receptors (specifically, Group I mGluR and CCK2 receptors). However, TRPC4 and TRPC5 subunits (members of the TRPC1/4/5 subfamily) can either form homomeric channels or heteromerize with the TRPC1 subunit, resulting in heterotetrameric TRPC channels with distinct biophysical and functional properties. These TRPCs can differentially regulate neuronal functions and, possibly, anxiety states, depending on their subunit composition. Combining genetic, behavioral, electrophysiological and optogenetic tools, we will explore the functional roles of distinct TRPC subunits and their combinations in structural components of the anxiety circuitry-the amygdala and BNST-and their contribution to control of anxiety-like behavioral responses. In our experiments, we will focus on the behavioral and functional analysis of mice lacking TRPC1, TRPC4 and TRPC5 (and combinations thereof) subunits. We will also study TrpC floxed mice in which TRPC subunits will be ablated specifically in subdivisions of the amygdala or BNST. In Aim 1, we will explore the roles of TRPC1/4/5 subfamily of TRPC channels in anxiety-like behaviors by probing anxiety levels in mice lacking different combinations of TRPC subunits. We will also investigate the effect of different TRPCs' ablation on synaptic functions, Gaq/11 protein-mediated signaling and neuronal spike output in intra-amygdala projections. We will then explore the role of TRPC channels in the function of local neuronal circuits in the amygdala (Aim 2). Specifically, we will examine whether the balance between excitation and inhibition in interdivisional projections in the amygdala is affected in neurons and interneurons in mutant mice. Finally (Aim 3), we will investigate the role of TRPC channels in regulation of synaptic and neuronal functions in the BNST, focusing on its two different subregions, the oval nucleus and anterodorsal BNST, known to exert opposing effects on anxiety. We will use optogenetic tools to achieve projection-specific activation of the fibers arising in the BLA and terminating in the BNST. We hypothesize that the ablation of TRPC1/4/5 subunits may modify the signal flow in the amygdala-BNST circuits, leading to the enhanced activation of adBNST and resulting in diminished anxiety-like responses, as adBNST activation was shown to be anxiolytic. These studies, illuminating the role of TRPC channels in anxiety-related behavioral processes, may contribute to our better understanding of how anxiety is regulated at the level of interacting components of the corresponding brain circuits.

 描述（由申请人提供）：驱动焦虑样行为的突触、神经元和神经网络机制尚未完全理解。瞬时受体电位通道（TRPC）属于TRPC 1/4/5亚家族，在涉及控制先天性恐惧反应的脑区中丰富，包括杏仁核和终纹床核（BNST）。与这种表达模式一致，我们最近发现，属于该亚家族的特定TRPC亚基可能有助于焦虑机制，可能通过激活Gaq/11蛋白偶联受体（特别是I组mGluR和CCK 2受体）调节大脑中特定神经回路内的信号流。然而，TRPC 4和TRPC 5亚基（TRPC 1/4/5亚家族的成员）可以形成同源通道或与TRPC 1亚基异聚化，导致异源四聚体TRPC通道具有不同的生物物理和功能特性。这些TRPC可以差异调节神经元功能，并可能，焦虑状态，这取决于它们的亚基组成。结合遗传，行为，电生理和光遗传学的工具，我们将探讨不同的TRPC亚基和它们的组合在焦虑回路的结构组成部分杏仁核和BNST的功能作用，以及它们对控制焦虑样行为反应的贡献。在我们的实验中，我们将专注于缺乏TRPC 1，TRPC 4和TRPC 5（及其组合）亚基的小鼠的行为和功能分析。我们还将研究TrpC floxed小鼠，其中TRPC亚基将在杏仁核或BNST的亚区中特异性消除。目的1：通过检测TRPC亚基不同组合缺失小鼠的焦虑水平，探讨TRPC通道TRPC 1/4/5亚家族在焦虑样行为中的作用。我们还将研究不同TRPC的消融对突触功能、Gaq/11蛋白介导的信号传导和杏仁核内投射中神经元锋电位输出的影响。然后，我们将探讨TRPC通道在杏仁核局部神经元回路功能中的作用（目的2）。具体来说，我们将研究是否兴奋和抑制之间的平衡在杏仁核的分区间的预测是在突变小鼠的神经元和中间神经元的影响。最后（目的3），我们将研究TRPC通道在调节BNST中的突触和神经元功能中的作用，重点关注其两个不同的亚区，卵圆核和前背侧BNST，已知对焦虑产生相反的影响。我们将使用光遗传学工具来实现BLA中产生并终止于BNST的纤维的投射特异性激活。我们假设TRPC 1/4/5亚基的消融可能会改变杏仁核-BNST回路中的信号流，导致adBNST激活增强，并导致焦虑样反应减弱，因为adBNST激活被证明具有抗焦虑作用。这些研究阐明了TRPC通道在焦虑相关行为过程中的作用，可能有助于我们更好地理解焦虑是如何在相应脑回路的相互作用组件水平上进行调节的。