Multipopulation voltage imaging for network insights in temporal lobe epilepsy

多人电压成像用于颞叶癫痫的网络洞察

• 批准号: 10823933
• 负责人: Madhuvanthi Kannan
• 金额: $ 42.63万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-18 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10823933
• 关键词: Address; Animals; Brain region; Cells; Chronic; Communities; Control Animal; Data; Data Set; Detection; Development; Disease; Dissection; Elements; Enhancers; Ensure; Epilepsy; Event; Exploratory/Developmental Grant; Future; Generations; Genetic Enhancer Element; Hippocampus; Image; Individual; Interneurons; Investigation; Kinetics; Medial; Membrane Potentials; Methods; Modeling; Modernization; Monitor; Neurons; Nuclear; Parvalbumins; Pattern; Photons; Population; Population Projection; Positioning Attribute; Prefrontal Cortex; Pyramidal Cells; Resolution; Seizures; Specific qualifier value; Structure; Synaptic Potentials; Temporal Lobe Epilepsy; Testing; Time; Training; Viral Vector; Work; awake; cell type; comorbidity; entorhinal cortex; epileptiform; experimental study; hippocampal pyramidal neuron; imaging modality; in vivo; inhibitory neuron; insight; kainate; millisecond; mouse model; neuronal patterning; neuroregulation; novel; optogenetics; postsynaptic; protein expression; red fluorescent protein; restraint; selective expression; technology development; tool; voltage

PROJECT ABSTRACT The hippocampus is a critical structure in mesial temporal lobe epilepsy (TLE), and is comprised of different cell types and subcircuits. How these circuit elements behave and importantly how they interact may provide key insights into epilepsy, including ictogenesis. Epilepsy is recognized as a “network disorder”; a proper understanding of network interactions in epilepsy is crucial to a full understanding of the disorder and consequently the development of novel treatment options. A new suite of voltage indicators allows unparalleled and simultaneous investigation of such circuit elements. We will therefore apply these cutting-edge methods in vivo, in awake, chronically epileptic animals, allowing us to answer questions not currently addressable with other methods – examining features including subthreshold membrane potential changes and resolving individual spikes even during high levels of activity. Using a mouse model of chronic TLE, we will image during periods free of overt epileptiform activity, during interictal spikes, during preictal periods, and throughout ictal activity, as well as postictal periods – providing us will a full picture of activity patterns across different ictal states. In this initial work, we focus on CA1 pyramidal neurons that project to the medial prefrontal cortex (PCmPFC) and CA1 pyramidal neurons that project to the medial entorhinal cortex (PCMEC), in addition to inhibitory neurons, including PV neurons specifically. These circuit elements were chosen due to their known and distinct interactions. Specifically, PCmPFC provide strong excitation to local PV neurons, but receive little inhibition from PV neurons. Conversely, PCMEC receive strong inhibition from local PV neurons but provide relatively limited excitation to PV neurons. We will therefore be able to examine, for the first time, how these circuit elements’ activity patterns relate to one another in vivo and how this changes in epileptic animals across the ictal spectrum. We predict that PV interneurons’ activity will be associated with reduced PCMEC but not PCmPFC pyramidal neuron activity in epileptiform-free states. During interictal spiking, we hypothesize that interneurons broadly are activated and that inhibition will constrain activity in both populations of pyramidal neurons during these events. We further predict that, unlike during interictal spikes, during ictal events, inhibitory neuronal firing will not be sufficient to restrain pyramidal cells, and they will be engaged even early during electrographic seizures. With continued ictal activity, we hypothesize that there will be a further breakdown in inhibitory restraint due to depolarization block in PV cells (but not other interneurons), resulting in a further increase in activity specifically in PCMEC neurons. If our hypotheses are incorrect, we gain equally valuable information about the activity patterns of these neuronal populations in chronic epilepsy. Additionally, this represents a fraction of the hypotheses testable with our data set and with future application of these methods to questions in epilepsy. We are committed to ensuring that the epilepsy community can implement these methods to address a wide range of important questions.

项目摘要 海马区是内侧颞叶癫痫(TLE)的关键结构，由不同的脑区组成。 单元类型和子电路。这些电路元件如何运行以及重要的是它们如何相互作用可以提供 对癫痫的关键见解，包括细胞发生。癫痫被认为是一种“网络障碍”；适当的 了解癫痫中的网络相互作用对于全面了解这种疾病和 因此，开发了新的治疗方案。一套新的电压指示器可以实现无与伦比的 并同时对这些电路元件进行研究。因此，我们将把这些尖端方法应用于 在清醒的慢性癫痫动物体内，允许我们回答目前无法解决的问题 其他方法-检查包括阈值下膜电位变化和分辨率在内的特征 即使在高水平的活动中，个体也会出现尖峰。使用慢性TLE的小鼠模型，我们将在 发作间期、发作前和整个发作期间无明显癫痫样活动的时期 活动，以及死后时期--为我们提供了不同发作期的活动模式的全貌 各州。在这项初步工作中，我们重点研究了投射到内侧前额叶皮质的CA1锥体神经元 (PCmPFC)和CA1锥体神经元投射到内侧内嗅皮质(PCMEC)。 抑制性神经元，特别是PV神经元。选择这些电路元件是因为它们的已知 和截然不同的互动。具体地说，PCmPFC给局部PV神经元提供了强烈的兴奋，但收到的信息很少 来自PV神经元的抑制。相反，PC微血管内皮细胞受到局部PV神经元的强烈抑制，但提供 对PV神经元的兴奋相对有限。因此，我们将能够第一次审查这些 体内电路元件的活动模式相互关联，以及在癫痫动物体内这种关系是如何变化的 发作期频谱。我们预测PV中间神经元的活动将与PC-微血管内皮细胞减少有关，但与此无关 无癫痫样状态下PC-的mPFC锥体神经元活性。在发作间歇期，我们假设 中间神经元被广泛激活，这种抑制将限制两组锥体细胞的活动 在这些事件中的神经元。我们进一步预测，与发作间歇期不同，在发作间歇期， 抑制神经元的放电将不足以抑制锥体细胞，它们甚至会很早就被激活。 在脑电抽搐的过程中。随着持续的发作活动，我们假设将会有更多的 由于去极化阻断PV细胞(但不是其他中间神经元)，导致抑制抑制的破坏，导致 PC-微血管内皮细胞活性进一步增强。如果我们的假设是错误的，我们就会平等地获益 关于慢性癫痫中这些神经元群体的活动模式的有价值的信息。另外， 这代表了可用我们的数据集和这些数据的未来应用验证的假设的一小部分 方法对癫痫患者的问题进行解答。我们致力于确保癫痫社区能够执行 这些方法解决了广泛的重要问题。