Regulation of Inhibitory Activity at Hippocampal Slices by Synapsin II and Rab3a

突触蛋白 II 和 Rab3a 对海马切片抑制活性的调节

• 批准号: 8785925
• 负责人: Pedro A. Feliciano-Ramos
• 金额: $ 3.18万
• 依托单位: UNIVERSIDAD CENTRAL DEL CARIBE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-30 至 2015-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8785925
• 关键词: Affect; Animals; Antiepileptogenic; Binding; Clinical Research; Complex; Data; Disease; Epilepsy; Equilibrium; Excitatory Synapse; Frequencies; Glutamates; Health; Hippocampus (Brain); Human; Inhibitory Synapse; Interneurons; Knock-out; Mus; Nervous System Physiology; Neurons; Phenotype; Physiological; Prevention; Proteins; Regulation; Research Priority; Role; Slice; Synapses; Synapsin I; Synapsin II; Synapsins; Synaptic Transmission; Testing; Therapeutic; Work; base; bindin; dentate gyrus; design; interest; nervous system disorder; neurotransmission; novel; novel strategies; public health relevance; research study; transmission process

DESCRIPTION (provided by applicant): Epilepsy is a complex and multifactorial neurological disorder, and now it is widely appreciated that changes in synaptic transmission often lie at the core of this disease. This has led to an increased interest in the role of synaptic proteins in thi disease. The best example of this are synaptic proteins synapsins, the main focus of this application. In mice, the deletion of synapsin I or synapsin II proteins results in a strong epilepic phenotype, and clinical studies demonstrated that synapsin deficiency is also associated with idiopathic epilepsy in humans. It was suggested that excitatory/inhibitory imbalance is one of the possible causes of the observed overexcitability. The applicant's recent study supports this hypothesis by directly demonstrating that synapsin II deletion differentially affects glutamatergic and GABAergic transmission at hippocampal slices and that epileptiform activity in SynII(-) slices is likely to result from impaired inhibition. Interestingly, deletion of the synapsin bindin partner Rab3a can suppress the epileptic phenotype observed in synapsin II deleted animals. This is obviously a potentially important observation that could help identify novel targets for th treatment of epilepsy. The experiments proposed in this application should help clarify the synaptic mechanisms that underlie the epileptogenic effects of synapsin II deletion as well as the physiological basis for the anti- epileptogenic effects of Rab3a deletion. The Specific Aim 1 proposes to investigate the role of synapsin II in the regulation of synchronous and asynchronous inhibitory transmission. Inhibitory asynchronous release following high-frequency discharges is thought to regulate epileptiform activity, and our preliminary data suggests that synapsin II deletion decreases the inhibitory asynchronous component in CA1 hippocampal interneurons. To elucidate the mechanism by which the deletion of synapsin II inhibits asynchronous release component, we will employ paired recordings of inhibitory transmission at hippocampal slices to rigorously examine synchronous and asynchronous quantal release at synapsin II deleted animals. The Specific Aim 2 proposes to understand how Rab3a deletion modifies the effect of Syn II deletion on synchronous and asynchronous inhibitory transmission. Since the deletion of Rab3a can neutralize synapsin-dependent epileptic seizures, we propose to investigate the asynchronous release component in the Rab3a(-) and in the SynII(-)/Rab3a(-) double knockout (DKO) neurons. Our preliminary data suggests that Rab3a deletion can restore the inhibitory asynchronous component reduced by the deletion of synapsin II. To understand by how Rab3a deletion can rescue the SynII(-) phenotype, we will investigate systematically synchronous and asynchronous release component at Rab3(-) and SynII(-)/Rabs3(-) DKO hippocampal slices and test whether the Rab3a incorporation into the SynII(-)/Rab3a(-) synapses can restore the SynII(-) phenotype.

描述(申请人提供)：癫痫是一种复杂和多因素的神经疾病，现在人们普遍认识到，突触传递的变化往往是这种疾病的核心。这导致了人们对突触蛋白在这种疾病中的作用越来越感兴趣。最好的例子是突触蛋白突触蛋白，这是这一应用的主要焦点。在小鼠中，突触素I或突触素II蛋白的缺失会导致强烈的癫痫表型，临床研究表明突触素缺乏也与人类的特发性癫痫有关。提示兴奋性/抑制性失衡是引起兴奋性过度的可能原因之一。申请人最近的研究直接证明突触素II的缺失对谷氨酸能产生不同的影响，从而支持了这一假说 和海马片的GABA能传递，SynII(-)脑片中的癫痫样活动可能是由于抑制受损所致。有趣的是，突触素结合蛋白配对Rab3a的缺失可以抑制突触素II缺失动物中观察到的癫痫表型。这显然是一项潜在的重要观察，可能有助于确定癫痫治疗的新靶点。本申请中提出的实验应有助于阐明突触素II缺失致癫痫作用的突触机制以及Rab3a缺失抗癫痫作用的生理基础。具体目的1建议研究突触素II在调节同步和异步抑制性传递中的作用。高频放电后抑制性非同步释放被认为调节癫痫样活动，我们的初步数据表明，突触素II缺失减少了CA1海马区中间神经元中抑制性非同步成分。为了阐明突触素II缺失抑制非同步释放组分的机制，我们将使用成对的海马片抑制传递记录来严格检测突触素II缺失的动物的同步和异步量子释放。具体目的2建议了解Rab3a缺失如何修改Syn II缺失对同步和异步抑制传输的影响。由于Rab3a的缺失可以中和突触素依赖的癫痫发作，我们建议研究Rab3a(-)和SynII(-)/Rab3a(-)双敲除(DKO)神经元中的异步释放成分。我们的初步数据表明，Rab3a的缺失可以恢复因突触素II的缺失而减少的抑制的异步成分。为了了解Rab3a缺失如何拯救SynII(-)表型，我们将系统地研究Rab3(-)和SynII(-)/Rab3(-)DKO脑片上的同步和异步释放成分，并测试Rab3a整合到SynII(-)/Rab3a(-)突触中是否能够恢复SynII(-)表型。