Timing of Neuronal Chloride Uptake for Control of Neonatal Seizure

项目概要和摘要 神经元氯离子浓度（[Cl-]i）是突触后GABAA- 受体介导的信号传导和细胞体积调节。损伤后，神经元通过吸收水分而膨胀 和氯化物盐。氯化物部分改变GABA信号传导的逆转电位， 抑制和促进早期抗惊厥药耐药性癫痫发作，被认为是恶化长期- 长期成果。神经元进入水和氯化物盐的一个重要途径是可逆的 阳离子-Cl-共转运体（CCC）NKCC 1和KCC 2。我们假设， 通过拮抗NKCC 1活性从缺氧-缺血恢复后的神经元氯离子内流，和/或 KCC 2活性是减少急性细胞肿胀和[Cl-]i的独特有效的治疗策略 升高受损神经元，恢复GABA能抑制，防止慢性[Cl-]i升高，复发 癫痫发作和癫痫发生。我们将在体外和体内测试这些假设， 缺氧缺血性损伤模型、转基因氯化物成像和多光子显微镜。的 本项目的总体目标是阐明阳离子氯离子转运活性在 缺氧缺血引起神经元损伤和癫痫发作。结果将有一个重要的积极意义 立即产生影响，因为它们将确定预防的最佳治疗窗口， 治疗患有缺氧缺血和高危新生儿的复发性癫痫发作 抗惊厥药抵抗性癫痫、癫痫、脑瘫和神经运动障碍。

Project Summary and Abstract Neuronal chloride concentration ([Cl-]i) is an important determinant of both post-synaptic GABAA- receptor mediated signaling and cell volume regulation. After injury, neurons swell by admitting water and chloride salts. The chloride moiety alters the reversal potential for GABA signaling, compromising inhibition and contributing to early anticonvulsant-resistant seizures that are thought to worsen long- term outcomes. An important pathway for neuronal entry of water and chloride salts are the reversible cation-Cl- cotransporters (CCC) NKCC1 and KCC2. We hypothesize that emergent limitation of neuronal chloride influx after recovery from hypoxia-ischemia by antagonizing NKCC1 activity and/or KCC2 activity is a uniquely effective therapeutic strategy to reduce acute cell swelling and [Cl-]i elevation in injured neurons, restore GABAergic inhibition, prevent chronic [Cl-]i elevation, recurrent seizures and epileptogenesis. We will test these hypotheses in vitro and in vivo using established models of hypoxic ischemic injury, transgenic chloride imaging, and multiphoton microscopy. The overall goal of this project is to elucidate the progressive role of cation-chloride transport activity in hypoxia-ischemia induced neuronal injury and seizures. The results will have an important positive impact immediately because they will identify an optimal therapeutic window for prevention and treatment of recurrent seizures in newborns that have suffered hypoxia-ischemia and are at high risk for developing anticonvulsant resistant seizures, epilepsy, cerebral palsy and neuromotor disabilities.