Mechanisms of Alcohol Withdrawal

描述（由申请人提供）：酒精滥用与多次酒精戒断事件相结合，在皮质下结构中产生类似于点燃的现象。根据饮酒的持续时间和戒断事件的数量，酒精戒断的临床症状可以从轻微到严重的震颤、多动症、意识模糊、幻觉、睡眠中断和癫痫发作。这些症状可能会随着每次戒断事件而恶化，并使诊断和治疗复杂化。潜在的戒断性癫痫发作是一种异常的大脑节律，它是由丘脑中的神经元发出有节律的动作电位爆发而产生的。这些爆发依赖于一类在大脑和外周表达的T型钙通道。尽管酒精戒断性癫痫发作和其他起源于丘脑的全身性癫痫发作之间有相似之处，但酒精戒断期间乙醇对丘脑功能的影响尚不清楚。理解这一点特别重要，因为丘脑节律异常先于海马和大脑皮层的异常节律的普遍化。本提案的总体目标是确定丘脑T型钙通道响应于多次戒断事件的变化的细胞和分子机制，以及这些机制如何导致酒精戒断发作。小鼠模型将用于探索这些机制，因为它具有所有三种T型钙通道亚型，并且是多次戒断性癫痫发作的良好模型。此外，它将使我们能够在我们的研究中整合高度乙醇敏感的T型通道亚型的敲除。在目标1中，我们建议记录戒断性癫痫发作，并使用我们开发的尖峰序列分析，以表征T型通道爆发性放电对癫痫发作发展的具体贡献。在目标2中，我们将描述皮层下结构中爆发放电发展的分子机制，我们将把爆发的发生率与我们在初步研究中观察到的基因和蛋白质增加联系起来。在目标3中，我们将使用高分辨率的全细胞斑片记录来确定我们观察到的基因和蛋白质表达的增加是否会导致钙电流的简单增加，或基本通道动力学的更复杂改变。公共卫生相关性我们将研究乙醇对乙醇敏感的钙离子通道的影响，这是酒精戒断发作的基础。除了大脑之外，该通道还涉及心脏、肺和肝脏的基本生物学和功能障碍，并且在某些癌症中表达，因此该通道的分子调节的研究通常对人类健康非常重要，并且与酒精戒断的理解特别相关。

DESCRIPTION (provided by applicant): Alcohol abuse, in combination with multiple alcohol withdrawal events, produces a phenomenon similar to kindling in subcortical structures. Depending on the duration of alcohol consumption and the number of withdrawal events the clinical symptoms of alcohol withdrawal can range from mild to gross tremors, hyperactivity, confusion, hallucinations, sleep disruption and seizures. These symptoms can worsen with each withdrawal event and complicate diagnosis and treatment. Underlying withdrawal seizure is an abnormal brain rhythm that is produced in the thalamus by neurons firing rhythmic bursts of action potentials. These bursts depend upon a class of T-type calcium channels that are expressed within the brain and periphery. Despite the similarities between alcohol withdrawal seizures and other generalized seizures of thalamic origin, the influence of ethanol on thalamic function during alcohol withdrawal is unknown. This is particularly important to understand because abnormal thalamic rhythms precede the generalization of abnormal rhythms in both the hippocampus and the cerebral cortex. The overall goal of this proposal is to determine cellular and molecular mechanisms underlying alterations in thalamic T-type calcium channels in response to multiple withdrawal events and how these contribute to alcohol withdrawal seizure. A mouse model will be used to explore these mechanisms because it possesses all three of the T-type calcium channel isoforms, and is a well-developed model for multiple withdrawal seizures. In addition, it will allow us to integrate a knockout of a highly ethanol-sensitive T-type channel isoform in our studies. In Aim 1, we propose to record withdrawal seizures and, using spike train analyses we have developed, to characterize the specific contribution of T-type channel burst discharges to the development of seizure. In Aim 2, we will characterize the molecular mechanisms underlying the development of burst firing in subcortical structures, and we will relate the incidence of bursts to the gene and protein increases we have observed in our preliminary studies. In Aim 3, we will use high resolution whole cell patch recordings to determine whether the increases in gene and protein expression we have observed produce simple increases in calcium currents, or more complex alterations in basic channel kinetics. PUBLIC HEALTH RELEVANCE We will examine the influence of ethanol on an ethanol-sensitive calcium channel that underlies alcohol withdrawal seizure. In addition to the brain, this channel is involved in the basic biology and dysfunction of the heart, lung and liver, and is expressed in certain cancers, thus studies of the molecular regulation of this channel are highly significant to human health generally, and are specifically relevant to the understanding of alcohol withdrawal.