Early Life Seizures and Development of Gabaergic Inhibition in the Human Brain

生命早期癫痫发作和人脑 Gabaergic 抑制的发展

• 批准号: 8545350
• 负责人: LAURA A JANSEN
• 金额: $ 19.18万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-14 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8545350
• 关键词: Early; Life; Seizures; Development; Gabaergic

DESCRIPTION (provided by applicant): Seizures in infants and neonates are common, are often resistant to currently used treatments, and can have devastating outcomes. The most frequently used anticonvulsant medications in this age group, the barbiturates and the benzodiazepines, act by enhancement of current through neuronal GABAA receptors. The focus of the current study is to characterize the development of human cortical GABAergic inhibition from late gestation through early childhood, and further to assess how this development is disrupted by conditions causing seizures in this age group. The underlying hypothesis of this proposal is that immature patterns of GABAA receptor subunit and cation-chloride cotransporter expression in human cortex result in pharmacologic properties predictive of low efficacy or even harmful consequences of the use of GABAergic agents in the treatment of premature infants, neonates, and young children. The Specific Aims of this proposal include: 1) Define the time course of the developmental maturation of human cortical GABAA receptor subunit and cation-chloride cotransporter expression, and assess abnormalities in expression related to early-life seizures due to malformations of cortical development. This aim will be achieved through the use of quantitative Western blot analysis with infrared fluorescence detection. Frozen postmortem and surgical cortical specimens will be collected from control infants at 20 weeks gestation through 3 years of age, as well as similarly-aged infants with seizures due to glioneuronal malformations of cortical development or migrational disorders. In addition, a clinical database will be constructed and correlated with our experimental data to assess whether variables that have been shown to modulate receptor or transporter expression in experimental epilepsy models might also play a significant role in our human epilepsy population. 2) Determine the functional and pharmacological consequences of developmental and seizure-associated changes in GABAA receptor subunit and cation-chloride cotransporter expression in human cortex. An innovative experimental paradigm will be utilized which allows electrophysiological analysis of GABAA receptors from frozen human brain tissue resulting in "microtransplantation" of native human receptors into the Xenopus oocyte plasma membrane. 3) Analyze alterations in the cellular distribution of GABAA receptor subunits and chloride transporters in human cortex related to early-life seizures. Funding from this Career Development Award will permit the PI to acquire expertise in the techniques of fluorescence immunohistochemistry and in situ hybridization to determine the cortical cell populations exhibiting changes in GABAergic properties during both normal human development and its disruption by seizures due to cortical malformations. Information gained as a result of this study could have direct clinical applications that produce improved medical and neurologic care of infants and neonates.

描述（由申请人提供）：婴儿和新生儿癫痫发作很常见，通常对目前使用的治疗有抵抗力，并可能产生破坏性后果。该年龄组最常用的抗惊厥药物巴比妥类和苯二氮卓类通过增强神经元GABAA受体电流发挥作用。本研究的重点是描述从妊娠晚期到幼儿期人类皮质GABA能抑制的发展，并进一步评估这种发展如何被该年龄组中引起癫痫发作的条件所破坏。该建议的基本假设是，GABAA受体亚单位和阳离子-氯离子协同转运蛋白在人皮质中表达的不成熟模式导致预测GABA能药物治疗早产儿、新生儿和幼儿的低疗效甚至有害后果的药理学性质。本提案的具体目的包括：1）确定人皮质GABAA受体亚单位和阳离子-氯离子共转运蛋白表达的发育成熟的时间过程，并评估与由于皮质发育畸形引起的早期癫痫发作相关的表达异常。这一目的将通过使用定量Western印迹分析与红外荧光检测来实现。将从妊娠20周至3岁的对照婴儿以及因皮质发育的胶质神经元畸形或移行性疾病而癫痫发作的同龄婴儿中采集冷冻尸检和手术皮质标本。此外，将构建一个临床数据库，并将其与我们的实验数据相关联，以评估已显示在实验性癫痫模型中调节受体或转运蛋白表达的变量是否也可能在我们的人类癫痫人群中发挥重要作用。2)确定人皮质中GABAA受体亚单位和阳离子-氯共转运蛋白表达的发育和发育相关变化的功能和药理学后果。一个创新的实验范例将被利用，它允许从冷冻人脑组织的GABAA受体的电生理分析，导致在“微移植”到非洲爪蟾卵母细胞质膜的天然人类受体。3)分析GABAA受体亚单位和氯离子转运蛋白在人类大脑皮层中与早期癫痫发作相关的细胞分布的变化。来自该职业发展奖的资金将允许PI获得荧光免疫组织化学和原位杂交技术方面的专业知识，以确定在正常人类发育过程中表现出GABA能特性变化的皮质细胞群及其因皮质畸形引起的癫痫发作造成的破坏。本研究获得的信息可能具有直接的临床应用，可改善婴儿和新生儿的医疗和神经护理。