TRPC-mediated control of anxiety

TRPC 介导的焦虑控制

• 批准号: 8972208
• 负责人: VADIM BOLSHAKOV
• 金额: $ 51.9万
• 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/8972208
• 关键词: Ablation; Address; Affect; Amygdaloid structure; Anterodorsal nucleus of thalamus; Anti-Anxiety Agents; Anxiety; Anxiety Disorders; Area; Automobile Driving; Aversive Stimulus; Beds; Behavioral; Behavioral Genetics; Biological Neural Networks; Brain; Cell Nucleus; Cells; Cholecystokinin B Receptor; Development; Equilibrium; Exhibits; Fiber; Fright; Genes; Goals; Interneurons; Knock-out; Knockout Mice; Knowledge; Lateral; Lead; Learning; Mediating; Metabotropic Glutamate Receptors; Mus; Mutant Strains Mice; Neurons; Output; Pattern; Phobias; Process; Property; Proteins; Publishing; Regulation; Relative (related person); 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-like behavior; anxious; behavioral outcome; behavioral response; biophysical properties; feeding; functional outcomes; generalized anxiety; inhibitory neuron; link protein; member; neural circuit; neuronal circuitry; neurotransmission; novel therapeutics; optogenetics; patch clamp; public health relevance; receptor; receptor coupling; relating to nervous system; research study; 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了解。瞬时受体电位通道 (TRPC) 属于 TRPC1/4/5 亚家族，在涉及先天恐惧反应控制的大脑区域中含量丰富，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 CCK2 受体）来调节大脑特定神经回路内的信号流。然而，TRPC4 和 TRPC5 亚基（TRPC1/4/5 亚家族的成员）可以形成同聚通道或与 TRPC1 亚基异聚，从而形成具有不同生物物理和功能特性的异四聚 TRPC 通道。这些 TRPC 可以差异性地调节神经元功能，甚至可能调节焦虑状态，具体取决于它们的亚基组成。结合遗传、行为、电生理和光遗传学工具，我们将探索不同 TRPC 亚基及其组合在焦虑回路结构成分（杏仁核和 BNST）中的功能作用，以及它们对控制焦虑样行为反应的贡献。在我们的实验中，我们将重点关注缺乏 TRPC1、TRPC4 和 TRPC5（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 的细分区域被专门消除。在目标 1 中，我们将通过探测缺乏不同 TRPC 亚基组合的小鼠的焦虑水平，探讨 TRPC 通道的 TRPC1/4/5 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的神经元尖峰输出的影响。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（目标 2）。具体来说，我们将检查突变小鼠的神经元和中间神经元中杏仁核间投射的兴奋和抑制之间的平衡是否受到影响。最后（目标 3），我们将研究 TRPC 通道在 BNST 突触和神经元功能调节中的作用，重点关注其两个不同的亚区域，卵圆核和前背侧 BNST，已知它们对焦虑产生相反的作用。我们将使用光遗传学工具来实现 BLA 中产生并终止于 BNST 中的纤维的投影特异性激活。我们假设 TRPC1/4/5 亚基的消融可能会改变杏仁核-BNST 回路中的信号流，导致 adBNST 的激活增强，并导致焦虑样反应减少，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如何在相应大脑回路的相互作用成分的水平上受到调节。