Probing epileptic circuits with novel Cre- and drug-regulated genetic approaches

用新型 Cre 和药物调节的遗传方法探索癫痫回路

基本信息

批准号：
8913446
负责人：
EDWARD PEREZ-REYES
金额：
$ 23.7万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-02-01 至 2017-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8913446
关键词：
Affect Aftercare American Animal Model Animals Appearance Back Behavior Birth Cells Cessation of life Cholecystokinin Clinical Complex Data Dendrites Dependovirus Development Disease Doxycycline Economics Electroencephalography Epilepsy Epileptogenesis Food Frequencies Functional disorder Future Generations Grant Hilar Hippocampus (Brain)Human Implant Injection of therapeutic agent Interneurons Left Measures Medical Medicine Methods Monitor Motor Seizures Mus Neurons Neurosciences Output Parvalbumins Pathology Patients Pharmaceutical Preparations Potassium Channel Publishing Pyramidal Cells Rattus Recurrence Replacement Therapy Research Rodent Sampling Science Sclerosis Seizures Serotyping Site Somatostatin Status Epilepticus Synapses Temporal Lobe Epilepsy Testing Time Transcriptional Activation Transplantation Tropism United States National Institutes of Health Viral Withdrawal base cell type critical period density dentate gyrus entorhinal cortex excitotoxicity genetic approach granule cell human FRAP1 protein innovation insight migration mimetics mossy fiber nervous system disorder neurogenesis neuronal circuitry neuropeptide Y neurotropic novel novel strategies optogenetics public health relevance recombinase research study response small molecule vesicular GABA transporter voltage

项目摘要

DESCRIPTION (provided by applicant): Epilepsy is a major neurological disorder with significant economic and human burdens. One of the most common forms is mesial temporal lobe epilepsy (TLE). Unfortunately, medical treatment of TLE fails in many cases, leaving a large unmet clinical need. Therefore, a thorough understanding of the neuronal circuits involved in seizure initiation and propagation will drive the development of novel therapies. A hallmark of mesial temporal lobe epilepsy for many patients is hippocampal sclerosis. The hippocampus is particularly susceptible to excitotoxicity. Key sites of neuronal death are the hilus of the dentat gyrus, where many inhibitory GABAergic interneurons are lost. Recurrent seizures trigger an increase in both neurogenesis and the development of remaining neurons. This is particularly true for the dentate gyrus, whose responses include: birth and migration of new granule cells, appearance of novel basal dendrites, and an increase in their axonal projections including excitatory collaterals back onto neighboring granule cells (mossy fiber sprouting). Which of all these responses is most responsible for the development of spontaneous seizures? This proposal will test the hypothesis that reduced activity of inhibitory interneurons is a key driver f epileptogenesis. This hypothesis was developed to explain the serendipitous finding that expression of a modified leak K+ channel (TREK-M) in rat dentate hilar neurons triggered limbic seizures similar to those that occur in TLE patients. The research will use a novel chemogenetic approach based on adeno-associated viral delivery of TREK-M whose expression is dependent on the action of Cre recombinase and regulated by doxycycline. This allows us to exploit Cre-driver mice that have been developed as a result of the NIH Neuroscience Blueprint. The ability of chemogenetic silencing of GABAergic neurons will be first tested in mice where Cre is expressed in all GABAergic interneurons. The first aim will validate delivery, record seizure activity, and examine the pathology that results, focusing on mossy fiber sprouting. The second aim will begin to dissect which of the many GABAergic subtypes are critical for seizure generation. This innovative chemogenetic approach will likely have a major impact on the field of neuroscience, as it provides a longer time scale to probe complex behaviors than is possible with optogenetics. The studies may also provide the first animal model of spontaneous recurrent seizures without neuronal death, which would mimic human TLE patients who do not show hippocampal sclerosis.

描述（由申请人提供）：癫痫是一种主要的神经系统疾病，具有重大的经济和人类负担，最常见的形式之一是内侧颞叶癫痫（TLE），不幸的是，在许多情况下，TLE 的药物治疗都失败了，留下了很大的空白。因此，对参与癫痫发作和传播的神经元回路的彻底了解将推动许多患者的内侧颞叶癫痫的新疗法的开发。海马硬化特别容易受到神经元死亡的影响，其中许多抑制性 GABA 能中间神经元的丢失会导致神经发生和剩余神经元的发育增加。对于齿状回来说也是如此，其反应包括：新颗粒细胞的诞生和迁移、新基底树突的出现以及轴突的增加包括兴奋性侧支细胞返回到邻近颗粒细胞（苔藓纤维发芽）的预测。所有这些反应中哪一个对自发性癫痫发作的发展最有影响？该提议将检验抑制性中间神经元活动减少是癫痫发生的关键驱动因素的假设。该研究的开发是为了解释一个偶然的发现，即大鼠齿状门门神经元中修饰的渗漏 K+ 通道 (TREK-M) 的表达引发了类似于 TLE 患者发生的边缘癫痫发作。研究将使用一种基于 TREK-M 的腺相关病毒传递的新型化学遗传学方法，TREK-M 的表达依赖于 Cre 重组酶的作用并受多西环素调节，这使我们能够利用因 TREK-M 而开发的 Cre 驱动小鼠。 NIH 神经科学蓝图将首先在所有 GABA 能中间神经元中表达 Cre 的小鼠中测试 GABA 能神经元的化学遗传学沉默的能力，第一个目标是验证传递、记录癫痫发作活动。研究由此产生的病理学，重点关注苔藓纤维发芽，剖析多种 GABA 亚型中哪些对癫痫发作至关重要，因为它提供了这种创新的化学遗传学方法可能会对神经科学领域产生重大影响。这些研究还可能提供第一个没有神经元死亡的自发性复发性癫痫发作的动物模型，该模型可以模仿没有表现出海马硬化的人类 TLE 患者。