Molecular genetic dissection of central amygdala microcircuitry underlying fear a

恐惧a背后的中央杏仁核微电路的分子遗传学解剖

• 批准号: 7871495
• 负责人: David J Anderson
• 金额: $ 40.5万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7871495
• 关键词: Adverse effects; Affect; Amygdaloid structure; Anatomy; Anterior; Anti-Anxiety Agents; Anxiety; Behavior; Behavioral; Behavioral Assay; Benzodiazepines; Brain; Brain Chemistry; Brain region; Buspirone; Capsaicin; Cell Nucleus; Cells; Central Lateral Nucleus; Chemicals; Chloride Channels; Complement; Cues; Data; Diagnosis; Disease; Dissection; Drug effect disorder; Emotional; Emotions; Extinction (Psychology); FOS gene; Figs - dietary; Freezing; Fright; Functional disorder; Generalized Anxiety Disorder; Generations; Genetic; Genetic Techniques; Glutamates; Infusion procedures; Interneurons; Ivermectin; Lateral; Learning; Light; Maps; Measures; Medial; Mediating; Mental Depression; Mental disorders; Methods; Molecular Genetics; Neurons; Output; Pharmaceutical Preparations; Play; Population; Post-Traumatic Stress Disorders; Prefrontal Cortex; Protein Kinase C; Public Health; Role; Schizophrenia; Serotonin Agents; Specificity; Stress; Structure; Synapses; System; Techniques; Testing; Therapeutic Intervention; base; behavior test; cellular targeting; cingulate cortex; conditioned fear; effective therapy; gain of function; improved; in vivo; loss of function; neural circuit; novel therapeutic intervention; public health relevance; research study; tool

DESCRIPTION (provided by applicant): Psychiatric disorders, such as PTSD, depression and generalized anxiety disorder, are increasingly being recognized as dysfunctions of specific brain circuits, rather than alterations in global "brain chemistry." In order to develop new therapeutic approaches based on an understanding of underlying disease mechanisms, it is necessary to understand the normal function of the affected circuits. In this application, we propose to apply new, genetically based, techniques for manipulating neuronal function and mapping neuronal connectivity, to dissect the microcircuitry that underlies conditioned fear and its extinction. Our focus is on understanding the function of subpopulations of interneurons located in the central nucleus of the amygdala (CeA), a brain region involved in emotion. One subset of these neurons is marked by expression of protein kinase C-4 (PKC-4). Our preliminary data indicate that genetically based inactivation of these neurons enhances conditioned freezing, suggesting that these neurons may normally act to gate output from CeA. Using a recently developed genetic system for neuronal silencing, based on an ivermectin (IVM)-gated chloride channel, and an "intersectional" strategy to target expression of this heteromeric channel exclusively to PKC-4 cells in CeA, we will test this hypothesis and investigate the functional role of these neurons in fear learning and fear extinction, as well as in unconditional fear and anxiety (Specific Aim I). In Specific Aim II, we will further investigate the role of these neurons using neuronal activation strategies based on light (channelrhodopsin-2) or chemical activation. These experiments will test the necessity and sufficiency, respectively, of PKC-4 neurons in emotional behaviors mediated by the amygdala. In Specific Aim III, we will map the inputs and outputs to and from these neurons, using genetically based neuronal tracing and electrophysiological techniques. Finally, in Specific Aim IV we will test the hypothesis that activation of PKC-4 neurons is required for the behavioral effects of anxiolytic drugs, such as benzodiazepines. These studies should begin to provide a functional dissection of the amygdala at the level of granularity of specific neuronal subtypes, and may identify new cellular targets for therapeutic intervention in psychiatric disorders. PUBLIC HEALTH RELEVANCE: Psychiatric disorders, such as depression, schizophrenia and post-traumatic stress disorder (PTSD), exact a significant toll on public health, yet current methods to diagnose and treat them are inadequate. In order to develop a new generation of more effective treatments for these illnesses, with fewer side-effects, it is necessary to identify the underlying brain circuits that are impaired, understand the normal function of these circuits in emotional behavior, and describe how this function is altered in a given disorder. The present proposal applies an arsenal of new, genetically based, tools for dissecting neural circuit function at a level of specificity that has not previously been achieved, to understand the 'gating' mechanisms that control the flow of information through the amygdala, a brain structure important in learning (and "unlearning") fear.

描述（由申请人提供）：PTSD，抑郁症和广义焦虑症等精神疾病越来越被认为是特定脑电路的功能障碍，而不是全球“脑化学”的改变。为了基于对潜在疾病机制的理解开发新的治疗方法，有必要了解受影响电路的正常功能。在此应用中，我们建议将基于遗传的新技术应用于操纵神经元功能和映射神经元连接性，以剖析构成条件恐惧及其灭绝的微电路。我们的重点是理解位于杏仁核中央核（CEA）的中间神经元的亚群的功能，杏仁核（CEA）是参与情感的大脑区域。这些神经元的一个子集以蛋白激酶C-4（PKC-4）的表达为特征。我们的初步数据表明，基于遗传学的这些神经元的失活会增强条件冻结，这表明这些神经元通常可以起作用CEA的门输出。 Using a recently developed genetic system for neuronal silencing, based on an ivermectin (IVM)-gated chloride channel, and an "intersectional" strategy to target expression of this heteromeric channel exclusively to PKC-4 cells in CeA, we will test this hypothesis and investigate the functional role of these neurons in fear learning and fear extinction, as well as in unconditional fear and anxiety (Specific Aim I).在特定的目标II中，我们将使用基于光（ChannelRhopopsin-2）或化学激活的神经元激活策略进一步研究这些神经元的作用。这些实验将分别测试由杏仁核介导的情绪行为中PKC-4神经元的必要性和充分性。在特定的目标III中，我们将使用基于遗传的神经元跟踪和电生理技术来绘制往返于这些神经元的输入和输出。最后，在特定的目标IV中，我们将检验以下假设：抗焦虑药（例如苯二氮卓类药物）的行为影响需要PKC-4神经元的激活。这些研究应开始在特定神经元亚型的粒度水平上提供杏仁核的功能解剖，并可以鉴定出针对精神疾病的治疗干预的新细胞靶标。公共卫生相关性：精神疾病，例如抑郁症，精神分裂症和创伤后应激障碍（PTSD），对公共卫生造成了重大伤害，但是当前的诊断和治疗方法是不足的。为了为这些疾病开发新一代的更有效的治疗方法，具有较少的副作用，有必要识别受损的潜在脑回路，了解这些电路在情感行为中的正常功能，并描述在给定疾病中该功能如何改变。本提案采用了新的，基于遗传的基于遗传的工具的武器，以在以前尚未达到的特异性水平上剖析神经回路功能，以了解控制信息通过杏仁核的“门控”机制，该机制通过杏仁核，这是一种大脑结构，这是一种对学习（和“学习”）的恐惧。