Timing of Neuronal Chloride Uptake for Control of Neonatal Seizure

项目摘要和摘要 神经元氯离子浓度([Cl-]i)是突触后GABAA-的重要决定因素 受体介导的信号和细胞体积调节。损伤后，神经元因吸收水分而肿胀 和氯盐。氯化物部分改变了GABA信号的逆转潜力，损害了 抑制和促进早期抗惊厥药物抵抗性癫痫发作，被认为是恶化长期- 期限结果。水和氯盐进入神经元的一条重要途径是可逆的 阳离子氯转运蛋白(CCC)NKCC1和KCC2。我们假设新出现的限制 通过拮抗NKCC1活性和/或抑制缺氧缺血恢复后神经元氯离子内流 KCC2活性是一种独特有效的治疗策略，可减少急性细胞肿胀和[Cl-]i 损伤神经元升高，恢复GABA能抑制，防止慢性[Cl-]i升高，复发 癫痫发作和癫痫的发生。我们将在体外和体内测试这些假设，使用已建立的 缺氧缺血损伤模型、转基因氯化物成像和多光子显微镜。这个 这个项目的总体目标是阐明阳离子-氯离子转运活动在 缺氧缺血引起神经元损伤和癫痫发作。这一结果将产生重要的积极影响 立即产生影响，因为他们将确定预防和治疗的最佳窗口 新生儿缺氧缺血高危反复惊厥的治疗 用于发展抗惊厥、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.