In Vitro Mechanisms of Ethanol Induced Neuronal Death.

在美国，胎儿酒精效应和胎儿酒精综合征占精神发育迟滞和行为障碍的很大比例，并造成巨大的个人和社会负担。 了解未成熟的神经系统如何对乙醇做出反应对于合理的干预策略至关重要。 电活动在体外和体内促进中枢神经系统（CNS）神经元的存活，并防止来自许多CNS区域的神经元的自然细胞死亡（NCD）。乙醇通过与N-甲基-D-天冬氨酸（NMDA）和γ-氨基丁酸（GABA）突触后受体相互作用抑制CNS电活动。 因此，乙醇可能会增强发育中的NCD。 最近的证据表明，乙醇暴露确实是有毒的前脑在体内的未成熟的神经元。 细胞损失的模式类似于谷氨酸受体阻断和GABA受体增强的组合产生的模式。 我们的证据表明，未成熟的海马神经元在体外也易受乙醇诱导的细胞损失，这表明易感性是受影响的神经元群体固有的，乙醇本身，而不是相关的代谢或营养变量，诱导神经元损失。 当长期暴露于GABA模拟物或NMDA受体阻断剂时，培养的海马神经元也会死亡。由所有三种治疗引起的细胞死亡通过慢性去极化神经元来防止。 因此，我们有一个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制问题。 我们将在体外研究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损失。 我们还将讨论钙信号传导的永久性或急性减少是否在细胞损失中很重要，并将确定细胞内钙增加对乙醇诱导的细胞损失提供神经保护的时间过程。 拟议的实验应该导致更好地了解前脑神经元易受乙醇诱导的死亡的机制。

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.