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

• 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
• 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

 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（由适用提供）：癫痫是一种主要的神经系统疾病，具有重大的经济和人类伯伦斯。最常见的形式之一是介体临时叶癫痫（TLE）。不幸的是，在许多情况下，TLE的医疗治疗失败了，留下了巨大的未满足的临床需求。因此，对参与癫痫发作和传播涉及的神经元电路的透彻理解将推动新疗法的发展。许多患者的介体临时爱癫痫的标志是海马硬化。海马特别容易受到兴奋性毒性。神经元死亡的关键部位是牙齿回，许多抑制性GABA能中间神经元丢失的。复发性癫痫发作会导致神经发生和剩余神经元的发展增加。对于齿状回的反应，其反应包括：新颗粒细胞的出生和迁移，新型基本树突的出现以及包括兴奋剂（兴奋剂）的增加的出现，将其归结为相邻的颗粒细胞（苔藓纤维发芽）。所有这些反应中的哪个最负责赞助地震的发展？该提案将检验以下假设：抑制性中间神经元的活性减少是关键驱动癫痫发生。这一假设的发展是为了解释一个偶然的发现，即在大鼠齿状肺门神经元中修饰的叶子K+通道（TREK-M）的表达触发了与TLE患者中发生的癫痫发作相似的边缘性癫痫发作。该研究将基于Trek-M的腺相关病毒递送的新化学生殖方法，其表达取决于CRE重组酶的作用并受强力霉素的调节。这使我们能够利用由于NIH神经科学蓝图而开发的Cre-Driver小鼠。首先在所有GABA能中间神经元中表达CRE的小鼠中测试GABA能神经元的化学生成沉默的能力。第一个目标将验证输送，记录癫痫发作活动并检查结果的病理，重点是苔藓纤维发芽。第二个目标将开始剖析许多GABA能亚型中的哪种对于癫痫发作至关重要。这种创新的化学生成方法可能会对神经科学领域产生重大影响，因为它为探测复杂行为的时间尺度比光遗传学所能提供的更长。这些研究还可以提供第一个没有神经元死亡的赞助复发性癫痫发作的动物模型，这会模仿不显示海马硬化症的人类TLE患者。