In Vitro Mechanisms of Ethanol Induced Neuronal Death.

乙醇诱导神经元死亡的体外机制。

• 批准号: 6651641
• 负责人: STEVEN J MENNERICK
• 金额: $ 21.18万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6651641
• 关键词: GABA receptor; NMDA receptors; apoptosis; calcium flux; ethanol; glutamates; hippocampus; laboratory rat; neural degeneration; neurons; neurotoxicology; neurotoxins

Fetal alcohol effects and fetal alcohol syndrome account for a large percentage of metal retardation and behavioral disorders in the United States and impose a tremendous personal and social burden. Understanding how the immature nervous system responds to ethanol is critical to rational intervention strategies. Electrical activity promotes survival of central nervous system (CNS) neurons in vitro and in vivo and prevents natural cell death (NCD) in neurons from many CNS regions. Ethanol depresses CNS electrical activity through interactions with both N-methyl-D-aspartate (NMDA) and gamma-aminobutyric acid (GABA) postsynaptic receptors. Thus it is possible that ethanol enhances developmental NCD. Recent evidence suggests that ethanol exposure is indeed toxic to immature neurons of the forebrain in vivo. The pattern of cell loss is similar to that produced by a combination of glutamate receptor blockade and GABA receptor potentiation. Our evidence suggests that immature hippocampal neurons in vitro are also susceptible to ethanol- induced cell loss, suggesting that susceptibility is intrinsic to neuronal populations affected and that ethanol itself, rather than associated metabolic or nutritional variables, induces the neuronal loss. Hippocampal neurons in culture also die when chronically exposed to GABAmimetics or NMDA receptor blockade. Cell death elicited by all three treatments is prevented by chronically depolarizing neurons. Thus, we have an in vitro model of ethanol-induced neuronal death that will allow us to explore mechanistic questions. We will examine the ultrastructural and biochemical profile of ethanol-induced hippocampal neuronal death in vitro. We will determine whether the interaction of ethanol with NMDA receptors and/or GABA receptors is sufficient to explain the neuronal loss observed in vitro. We will also address whether permanent or acute decreases in calcium signaling are important in cell loss and will determine the time course over which increases in intracellular calcium provide neuroprotection against ethanol-induced cell loss. The proposed experiments should lead to a better fundamental understanding of the mechanisms by which forebrain neurons are susceptible to ethanol-induced death.

胎儿酒精效应和胎儿酒精综合征在美国占金属迟缓和行为障碍的很大一部分，并造成了巨大的个人和社会负担。 了解未成熟的神经系统对乙醇的反应对于理性干预策略至关重要。 电活动在体外和体内促进中枢神经系统（CNS）神经元的存活，并防止许多CNS区域的神经元中自然细胞死亡（NCD）。乙醇通过与N-甲基-D-天冬氨酸（NMDA）和γ-氨基丁酸（GABA）突触后受体的相互作用来抑制CNS电活动。 因此，乙醇可能增强发育NCD。 最近的证据表明，乙醇暴露确实对体内前脑的未成熟神经元有毒。 细胞损失的模式与谷氨酸受体阻滞和GABA受体增强的组合产生的模式相似。 我们的证据表明，体外未成熟的海马神经元也容易受到乙醇诱导的细胞损失的影响，这表明易感性对受影响的神经元群体固有，而乙醇本身，而不是相关的代谢或营养变量，可诱发神经元丧失。 当长期暴露于gabamimetics或NMDA受体阻滞剂时，培养中的海马神经元也会死亡。所有三种治疗引起的细胞死亡都是通过慢性去极化神经元预防的。 因此，我们具有乙醇诱导的神经元死亡的体外模型，这将使​​我们能够探索机械性问题。 我们将检查体外乙醇诱导的海马神经元死亡的超微结构和生化特征。 我们将确定乙醇与NMDA受体和/或GABA受体的相互作用是否足以解释体外观察到的神经元丧失。 我们还将解决钙信号的永久性或急性减少在细胞损失中是否重要，并确定细胞内钙增加的时间过程可为乙醇诱导的细胞损失提供神经保护作用。 提出的实验应导致对前脑神经元容易受到乙醇引起的死亡的机制有更好的基本理解。