Identifying a Role for Vasoactive Intestinal Peptide Expressing Interneurons in a Mouse Model of Dravet Syndrome

鉴定血管活性肠肽表达中间神经元在 Dravet 综合征小鼠模型中的作用

• 批准号: 10062835
• 负责人: Kevin Goff
• 金额: $ 3.32万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2021-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10062835
• 关键词: Achievement; Action Potentials; Acute; Affect; Age; Attention; Axon; Behavior; Brain; Calcium; Cells; Childhood; Clinical; Code; Cognitive; Complex; Confocal Microscopy; Data; Development; Disease; Disease model; Disinhibition; Electrophysiology (science); Epilepsy; ErbB4 gene; Exhibits; Experimental Models; Fellowship; Foundations; Functional disorder; Future; Gene Expression; Generations; Genes; Genetic; Glutamates; Goals; Human; Image; Imaging Techniques; Immunohistochemistry; Impaired cognition; Impairment; In Vitro; Individual; Intellectual functioning disability; Interneurons; Intractable Epilepsy; Ion Channel; Ions; Learning; Link; Locomotion; Measures; Mediating; Methods; Modeling; Molecular Biology; Morphology; Motor Cortex; Mus; Mutation; National Research Service Awards; Neurodevelopmental Disorder; Neurologic; Neurons; Neurosciences Research; Parvalbumins; Pathogenesis; Pharmacology; Phenocopy; Phenotype; Physicians; Physiology; Positioning Attribute; Prognosis; Property; Pyramidal Cells; Research; Role; Running; Schizophrenia; Scientist; Seizures; Sensory; Slice; Sodium; Sodium Channel; Somatosensory Cortex; Somatostatin; Sudden Death; Synapses; Syndrome; Temperature; Testing; Therapeutic; Therapeutic Intervention; Training; Translating; Vasoactive Intestinal Peptide; Wakefulness; Whole-Cell Recordings; Work; autism spectrum disorder; autistic; awake; barrel cortex; base; career; cholinergic; design; doctoral student; dravet syndrome; effective therapy; experience; experimental study; functional disability; in vivo; in vivo calcium imaging; in vivo imaging; loss of function mutation; mouse model; neuroregulation; novel; optogenetics; pre-clinical; recruit; sensory integration; synaptogenesis; targeted treatment; translational neuroscience; two-photon; voltage

PROJECT SUMMARY: I am applying for this NRSA fellowship as an MD/PhD student with the long-term goal of becoming a successful physician scientist running my own translational neuroscience research lab. This project is designed to give me the training and experience required towards achievement of this goal. The goal of the project is to investigate the mechanisms of epilepsy and cognitive impairment in Dravet syndrome. Dravet syndrome is a severe neurodevelopmental disorder of childhood defined by epilepsy and autism that is currently without cure or disease-modifying therapy. This syndrome is caused by mutations in the gene SCN1A, which codes for the voltage gated sodium channel alpha subunit Nav1.1. Based on work in a mouse model of Dravet Syndrome, it is hypothesized that GABAergic interneurons – particularly the subsets marked by expression of parvalbumin (PV-INs) and somatostatin (SST-INs) – are selectively impaired, while excitatory glutamatergic neurons are not affected. Interneurons are classically considered to be inhibitory, so loss of Nav1.1 in interneurons is thought to cause decreased inhibition in the developing brain with resulting cognitive impairment and epilepsy. However, interneurons are incredibly diverse in terms of gene expression, morphology, electrophysiological properties, and synaptic connectivity. Interneurons marked by expression of vasoactive intestinal peptide (VIP-INs) constitute a third prominent subset of interneurons that form distinct disinhibitory circuits by primarily targeting other interneurons, and thereby regulate cognitive processing, attention, and learning, functions which are impaired in Dravet Syndrome. However, no previous study has investigated whether VIP-INs are impaired in this model. I show preliminary data indicating that VIP-INs do express Nav1.1 and have impaired excitability in a mouse model of Dravet Syndrome. I hypothesize that this leads to dysfunction of disinhibitory microcircuits that underlie sensory processing and brain state modulation. In Aim1, I use slice electrophysiology, immunohistochemistry, and pharmacology to show that VIP-INs in fact express Nav1.1 and are functionally impaired in Dravet syndrome mice. In Aim 2, I will investigate the effect of VIP interneuron dysfunction on the activity of a specific sensorimotor circuit in Dravet Syndrome mice using optogenetics and synaptic physiology. Finally, in Aim 3, I will use two-photon calcium imaging to study cortical dynamics that depend on VIP-IN activity in awake behaving DS mice in vivo. Results will implicate VIP-IN dysfunction in the pathogenesis of Dravet syndrome and suggest novel avenues for therapy.

项目总结： 我以医学博士研究生的身份申请NRSA奖学金，我的长期目标是成为一名成功的 经营着我自己的翻译神经科学研究实验室的内科科学家。这个项目是为了给我 为实现这一目标所需的培训和经验。 该项目的目标是研究德拉维癫痫和认知障碍的机制。 综合症。德拉韦综合征是一种严重的儿童神经发育障碍，其定义为癫痫和 目前没有治愈或疾病修正疗法的自闭症。这种综合征是由基因突变引起的 基因SCN1a，编码电压门控钠通道α亚基NAV1.1。基于工作中的 Dravet综合征小鼠模型的建立，推测GABA能中间神经元--尤其是亚群 以小白蛋白(PV-INS)和生长抑素(SST-INS)的表达为标志的-是选择性受损的，而 兴奋性谷氨酸能神经元不受影响。中间神经元被经典地认为是抑制性的，所以 中间神经元中Nav1.1的丢失被认为会导致发育中的大脑抑制作用减弱，从而导致 认知障碍和癫痫。然而，就基因表达而言，中间神经元的多样性令人难以置信， 形态、电生理特性和突触连接。标记的中间神经元 血管活性肠肽(VIP-INS)构成中间神经元的第三个重要亚群，形成不同的 通过主要针对其他中间神经元来解除抑制回路，从而调节认知过程， 注意力和学习功能在德拉韦氏综合症中受损。然而，之前没有一项研究表明 已调查VIP-INS在此模型中是否受损。我展示了初步数据，表明VIP-INS 表达Nav1.1，并在Dravet综合征小鼠模型中损害兴奋性。我假设这是 导致作为感觉处理和大脑状态调节基础的去抑制微电路功能障碍。在……里面 目的：利用切片电生理学、免疫组织化学和药理学的方法，证明VIP-ins实际上是 表达Nav1.1，并在Dravet综合征小鼠中功能受损。在目标2中，我将调查 血管活性肠肽中间神经元功能障碍对Dravet综合征小鼠特定感觉运动回路活动的影响 光遗传学和突触生理学。最后，在目标3中，我将使用双光子钙成像来研究大脑皮层 清醒的DS小鼠体内VIP-IN活性的动态变化。结果将牵涉到VIP-IN 德拉韦综合征发病机制中的功能障碍，并提出了新的治疗途径。