The impact of alcohol addiction on circuit dynamics in the extended amygdala

描述(由申请人提供)：本提案涉及广泛的挑战领域(06)“使能技术”和具体的挑战主题06-AA-106“酒精相关神经电路分析的技术发展”。这项提案的申请者一直在成功地开展跨学科合作，以应对这一专题所引起注意的科学和技术挑战。显然，尽管在过去20年中积累了大量关于酒精影响的分子和细胞机制的数据，但用于分析与酒精相关的神经电路和动力学的先进技术一直没有得到充分利用。使用最先进的电生理学和计算技术研究酒精影响的神经回路将为更好地理解与成瘾和戒断的行为影响密切相关的回路和系统水平的机制提供机会。事实上，这是我们建议的主要目标。在这两个具体目标下描述的工作将包括开发和优化以前没有用于酒精相关神经电路研究的新技术。着眼于杏仁核，大脑动机/奖励系统中最重要的区域之一，我们提出了一系列复杂的电生理学方法的实验，将从系统神经科学的角度揭示酒精依赖和戒断的神经机制。在第一个特定目标中，我们将描述终纹囊床旁核(jcBNST，杏仁核延伸回路的中心元件)神经元的整合和动力学特性与它们在正常动物和依赖动物中的内在生物物理特性的关系。下一步，我们将描述已知在酒精依赖中发挥重要作用的神经调节输入如何改变jcBNST神经元的动态反应。在这里，我们将使用一种基于计算机的电生理技术，称为动态钳夹。这项技术将使我们能够以极高的精度和时间分辨率分析细胞动力学和电路相互作用，同时保持神经元处于高电导状态，与完整大脑中的状态相似。这种方法的新奇之处在于，动态钳制将展示它们如何在活跃的、时间复杂的突触环境中发挥作用，以及与酒精相关的内在特性变化如何影响它们的输出。我们还将能够检测和分析复杂形式的神经计算，例如细胞共振和模式选择性，以前没有详细研究过。在第二个特定目标中，我们将研究酒精在电路水平相互作用、可塑性以及多巴胺和促肾上腺皮质激素释放因子的调节作用。对于这些实验，我们将建立一个新的电生理系统，能够同时记录数十个神经元的尖峰活动，并将时空结构的刺激模式传送到神经回路。这个多电极系统将使我们能够观察到与酒精相关的突触连接、jcBNST内的信号转导及其对下行神经元群体的整体网络输出的变化。虽然在这个项目中，我们将专注于已知受酒精和药物滥用影响最大的特定大脑区域，但我们所使用的技术的广泛适用性将为研究与大脑其他功能相关的科学和健康问题打开可能性。这将加强我们研究的长期影响。除了科学上的好处，该项目还将通过创新和创造就业机会为地区和国家经济的发展做出贡献。未来的经济安全将通过立即雇用一名早期调查员(首席调查员)和两名博士后学者来促进。这项提案中描述的创新研究计划将为合作和更有干劲的年轻科学家的参与开辟更多的可能性。长期影响将是新知识的产生，为确定治疗与酒精成瘾有关的神经/行为障碍的治疗目标以及开发新的复发治疗目标作出重要贡献。拟议的研究还将有助于可能开发适用于生物系统的新的创新技术，以及超出当前项目范围的科学挑战。利用世邦魏理仕咨询公司在最近对加州大学圣迭戈分校对经济影响的评估中开发的方法，该项目估计将创造9个新的就业机会，并在加利福尼亚州产生约100万美元的总支出。考虑到分包机构与地方和国家经济的动态互动，斯克里普斯研究所也可以做出类似的估计。 公共卫生相关性：该项目旨在更好地了解酒精成瘾和戒断如何在单个神经元和神经回路水平上影响中枢神经系统的神经元通讯。具体地说，我们将开发和优化研究酒精相关神经回路功能障碍的技术，这将极大地有助于更好地了解酒精成瘾的发病机制。最终，该项目将有助于开发新的治疗概念，提供更多的社会经济利益。

DESCRIPTION (provided by applicant): This proposal addresses broad Challenge Area (06) 'Enabling Technologies' and specific Challenge Topic 06-AA-106, 'Technology Development for Analysis of Alcohol-Related Neural Circuits'. The applicants of this proposal have been conducting a successful interdisciplinary collaboration addressing the very scientific and technological challenges this Topic calls attention to. Clearly, advanced technologies for the analysis of alcohol-related neural circuits and dynamics have been underutilized in spite of the immense amount of data on the alcohol-affected molecular and cellular mechanisms that have been accumulated during the past two decades. Using state-of-the-art electrophysiological and computational techniques in the research of alcohol-impacted neural circuits would provide the opportunity for a better understanding of the circuit- and systemic level mechanisms that are closely related to the behavioral effects of addiction and withdrawal. In fact, this is the primary objective of our proposal. Work described under the two Specific Aims will include development and optimization of novel technologies previously not utilized in the research of alcohol-related neural circuits. Focusing on one the extended amygdala, one of the most important areas in the motivational/reward system of the brain, we propose a series of experiments with sophisticated electrophysiological methods that will shed light on the neural mechanisms of alcohol dependence and withdrawal from a systems neuroscience perspective. In the first Specific Aim we will characterize the integrative and dynamical properties of neurons in the juxtacapsular bed nucleus of stria terminalis (jcBNST, a central element of the extended amygdala circuits) in relation to their intrinsic biophysical properties both in normal and in dependent animals. Next we will characterize how neuromodulatory inputs known to play important roles in alcohol dependence change the dynamical responses of jcBNST neurons. Here, we will use a computer-based electrophysiological technique referred to as dynamic clamp. This technique will allow us to analyze cellular dynamics and circuit interactions with great accuracy and temporal resolution while maintaining the neurons in a high conductance state, smilar to that in the intact brain. The novelty of this approach is that the dynamic clamp will show how they function in an active, temporally complex synaptic environment and how alcohol-related changes in their intrinsic properties impact their output. We will also be able to detect and analyze sophisticated forms of neural computation, such as cellular resonance and pattern selectivity previously not investigated in details. In the second Specific Aim we will study the effects of alcohol at circuit-level interactions, plasticity and modulation by dopamine and corticotropin releasing factor. For these experiments we will build a new electrophysiological system capable of simultaneously recording the spike activity of tens of neurons and delivering spatiotemporally structured stimulus patterns into the neural circuit. This multielectrode system will allow us to observe alcohol-related changes in the synaptic connectivity, signal transduction within the jcBNST and its overall network output to downstrem neuron populations. While in this project we will focus on a specific brain area that is known to be among the most impacted by alcohol and drugs of abuse, the wide applicability of the techniques we utilize will open possibilities for research addressing scientific and health problems related to other functions of the brain. This will strengthen the long-term impact of our research. In addition to the scientific benefits, this project will contribute to the development of the regional and national economy through innovation and job creation. Future economic security will be promoted through the immediate employment of an early stage investigator (the principal investigator) and two postdoctoral scholars. The innovative research program described in this proposal will open further possibilities for collaborations and the involvement of more motivated young scientists. The long term impact will be the generation of new knowledge providing an important contribution to the identification of therapeutical targets for the treatment of neural/behavioral disorders associated with alcohol addiction as well as to the development of new therapeutical targets for relapse. The proposed research will also contribute to possible development of new, innovative technologies applicable to biological systems and scientific challenges beyond the scope of the current project. Using methodology recently developed by CBRE Consulting Inc. in a recent evaluation of the impact of UCSD on the economy, this project is estimated to create 9 new jobs and result in approximately $1 million in total spending in California. Considering the dynamic interaction of the subcontracting institution with the local and national economy, a similar estimation can be made for The Scripps Research Institute. PUBLIC HEALTH RELEVANCE: This project aims to achieve a better understanding of how alcohol addiction and withdrawal affects neuronal communication in the central nervous system at levels of single neurons and neural circuits. Specifically, we will develop and optimize technologies for the study of alcohol-related dysfunctions of neural circuits that will greatly contribute to a better understanding of the pathogenesis of alcohol addiction. Ultimately, this project will contribute to the development of novel therapeutical concepts providing additional socio-economic benefit.