Early-Life Seizures and Development of GABAergic Inhibition in the Human Brain

人脑中早期癫痫发作和 GABA 能抑制的发展

• 批准号: 8189659
• 负责人: LAURA A JANSEN
• 金额: $ 18.46万
• 依托单位: SEATTLE CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8189659
• 关键词: 3 year old; Address; Age; Animal Model; Antibodies; Anticonvulsants; Astrocytes; Autopsy; Barbiturates; Benzodiazepines; Brain; Brain region; Cations; Cell membrane; Cells; Cellular Membrane; Child; Chloride Ion; Chlorides; Clinical; Cortical Malformation; Data; Databases; Detection; Development; Disease; Electrodes; Electrophysiology (science); Epilepsy; Exhibits; Exposure to; Fluorescence; Freezing; Frequencies; Funding; GABA Agents; Glutamates; Goals; Human; Human Development; Immunohistochemistry; In Situ Hybridization; Infant; Infant Care; Injection of therapeutic agent; Interneurons; K-Series Research Career Programs; Label; Life; Medical; Membrane; Modeling; Neonatal; Neurologic; Neurons; Oocytes; Operative Surgical Procedures; Outcome; Pathology; Patients; Pattern; Pharmaceutical Preparations; Play; Population; Pregnancy; Premature Infant; Preparation; Property; Pyramidal Cells; Relative (related person); Resected; Resistance; Role; Sedation procedure; Seizures; Specimen; Techniques; Therapeutic; Time; Western Blotting; Xenopus oocyte; age group; aged; barbituric acid salt; base; brain tissue; cell type; clinical application; early childhood; gamma-Aminobutyric Acid; improved; innovation; neonate; neurosteroids; receptor; sex; voltage clamp

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. PUBLIC HEALTH RELEVANCE: Currently used treatments for neonatal seizures that target neuronal GABAA receptors are often ineffective and, based on data from animal models, may actually be detrimental. The goal of this proposal 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. Results from this study may encourage the reconsideration of the use of GABAergic medications in the treatment of seizures or sedation in infants and neonates, and also suggest better therapeutic alternatives.

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，并且可能产生毁灭性的后果。该年龄段最常用的抗惊厥药物是巴比妥类药物和苯二氮卓类药物，它们通过增强神经元 GABAA 受体的电流来发挥作用。当前研究的重点是表征从妊娠晚期到儿童早期人类皮质 GABA 能抑制的发展，并进一步评估该年龄组中引起癫痫发作的情况如何干扰这种发展。该提案的基本假设是，人类皮质中 GABAA 受体亚基和阳离子-氯化物协同转运蛋白表达的不成熟模式导致药理学特性，预示着使用 GABA 能药物治疗早产儿、新生儿、和幼儿。该提案的具体目标包括： 1) 定义人类皮质 GABAA 受体亚基和阳离子-氯化物协同转运蛋白表达发育成熟的时间过程，并评估由于皮质发育畸形而导致的与早期癫痫发作相关的表达异常。这一目标将通过使用定量蛋白质印迹分析和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迁移障碍而癫痫发作的同龄婴儿收集冷冻尸检和手术皮质标本。此外，还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) 确定人类皮质中 GABAA 受体亚基和阳离子-氯化物协同转运蛋白表达的发育和癫痫相关变化的功能和药理学后果。将利用创新的实验范例，对冷冻人脑组织的 GABAA 受体进行电生理分析，从而将天然人类受体“微移植”到非洲爪蟾卵母细胞质膜中。 3) 分析与生命早期癫痫发作相关的人类皮质中 GABAA 受体亚基和氯离子转运蛋白的细胞分布变化。该职业发展奖的资助将使 PI 能够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以及因皮质畸形引起的癫痫发作而破坏的皮质细胞群中表现出 GABA 能特性变化的皮质细胞群。这项研究获得的信息可以直接应用于临床，改善婴儿和新生儿的医疗和神经护理。 公共卫生相关性：目前针对神经元 GABAA 受体的新生儿癫痫发作治疗方法通常无效，并且根据动物模型的数据，实际上可能是有害的。该提案的目的是描述从妊娠晚期到儿童早期人类皮质 GABA 能抑制的发展，并进一步评估该年龄组中引起癫痫发作的情况如何干扰这种发展。这项研究的结果可能会鼓励人们重新考虑使用 GABA 能药物治疗婴儿和新生儿的癫痫发作或镇静，并提出更好的治疗替代方案。