Exploring the role of oxytocin in the regulation of neuronal excitability

项目摘要 电压门控钠通道（VGSC）的功能障碍是导致几种形式的灾难性 儿童脑病已鉴定出VGSC SCN 1A中超过1000种功能丧失突变 在过去的二十年中，是Dravet综合征（DS）的主要原因，其特征是复发性早期- 终身热性惊厥（FS），严重的无热性癫痫，认知和行为缺陷，死亡率为15-20% 率最近在2012年发现了VGSC SCN 8A的突变，并且已经有超过200个功能获得性突变。 据报道，SCN 8A突变存在于具有一系列临床特征的患者中，包括灾难性的 难治性儿童癫痫、自闭症、智力残疾和发育迟缓。不幸的是， 大多数抗癫痫药物（AEDs）不能充分治疗广泛的严重癫痫发作和行为障碍， SCN 1A和SCN 8A衍生癫痫患者的表型。因此，尽管最近在 尽管药物治疗DS的效果不佳，但仍然需要开发更有效、更持久的治疗方法， 副作用更少。众所周知，在动物研究中，神经肽显示出很大的控制前景。 癫痫发作和改善行为异常;然而，它们不容易穿过血脑屏障 并且在全身给药时迅速代谢。因此，较差的大脑睡眠是一个关键的障碍， 这些有前途的治疗方法的临床应用。为了克服这一挑战，我们开发并验证了 基于神经肽在与狂犬病病毒糖蛋白缀合的纳米颗粒中的包封的方法 （RVG）。使用这种方法，我们发现鼻内递送纳米颗粒包封的催产素（NP-1）， OT）大大增加了大脑的清醒度和OT赋予大脑活力和持续增长的能力。 在SCN 1A和SCN 8A功能障碍的小鼠模型中对癫痫发作的抵抗。我们还扩展了我们的战略 包封神经肽Y（NP-NPY），并类似地观察到其赋予 抗癫痫在这项研究中，我们将建立NP-OT和NP-NPY改善 Scn 1a和Scn 8a小鼠突变体的自发性癫痫发作和行为异常（目的1）。虽然角色 OT在社会行为中的作用已得到充分研究，但对它调节癫痫发作的机制知之甚少 易感性因此，我们也将确定有助于能力的细胞和神经回路机制， OT增加Scn 1a和Scn 8a突变体的癫痫发作抗性（目的2）。我们的长期目标是发展 用于治疗癫痫和其他疾病的神经肽脑递送的安全有效的方法 神经系统疾病

PROJECT SUMMARY Dysfunction of voltage-gated sodium channels (VGSCs) is responsible for several forms of catastrophic childhood encephalopathies. Over 1000 loss-of-function mutations in the VGSC SCN1A have been identified during the last two decades and are the main cause of Dravet syndrome (DS), characterized by recurrent early- life febrile seizures (FSs), severe afebrile epilepsy, cognitive and behavioral deficits, and a 15-20% mortality rate. Mutations in the VGSC SCN8A were more recently identified in 2012, and already over 200 gain-of-function SCN8A mutations have been reported in patients with a range of clinical features including catastrophic treatment-resistant childhood epilepsy, autism, intellectual disability and developmental delay. Unfortunately, most anti-epileptic drugs (AEDs) fail to adequately treat the broad range of severe seizures and behavioral phenotypes in patients with SCN1A- and SCN8A-derived epilepsy. Thus, despite recent progress in pharmacological treatments for DS, there remains a need to develop more effective, longer lasting treatments with fewer side effects. Neuropeptides are well known in animal studies to show great promise for controlling seizures and ameliorating behavioral abnormalities; however, they do not readily cross the blood brain barrier and are rapidly metabolized when given systemically. Thus, poor brain penetrance is a critical barrier to the clinical application of these promising therapeutics. To overcome this challenge, we developed and validated an approach based on the encapsulation of neuropeptides in nanoparticles conjugated to rabies virus glycoprotein (RVG). Using this approach, we have found that intranasal delivery of nanoparticle-encapsulated oxytocin (NP- OT) greatly increases brain penetrance and the capacity of OT to confer robust and sustained increases in resistance to seizures in mouse models of SCN1A and SCN8A dysfunction. We have also extended our strategy to encapsulate neuropeptide Y (NP-NPY), and similarly observed a robust improvement in its ability to confer seizure resistance. In the proposed study, we will establish the ability of NP-OT and NP-NPY to ameliorate spontaneous seizures and behavioral abnormalities in Scn1a and Scn8a mouse mutants (Aim 1). While the role of OT in social behavior is well-studied, less is known about the mechanisms by which it modulates seizure susceptibility. Thus, we will also identify the cellular and neural circuit mechanisms that contribute to the ability of OT to increase seizure resistance in the Scn1a and Scn8a mutants (Aim 2). Our long-term goal is to develop safe and effective approaches for the brain delivery of neuropeptides for the treatment of epilepsy and other neurological disorders.