MOLECULAR MECHANISM OF ALCOHOL SELF ADMINISTRATION

描述（由申请人提供）：本项目的主要目标是了解分子 影响酒精自我管理和依赖性的适应性变化的机制，这些变化是由反复的酒精暴露和戒断引起的。大量证据表明，神经元γ-氨基-丁酸A型（GABAA）受体调节酒精自我给药和酒精戒断严重程度。我们的研究表明，突变小鼠缺乏蛋白激酶C（PKC β）亚型的急性酒精和GABAA变构阳性调节剂超敏感。这种超敏反应与酒精自我给药减少、无酒精剥夺效应（ADE）和无乙醇戒断癫痫严重程度进展相关。相比之下，PKC γ无效突变小鼠对GABAA受体功能的乙醇调节不太敏感，并且饮用更多的乙醇，这表明PKC的特定同种型可能差异地调节GABAA介导的乙醇作用。目前的建议扩展了这些研究结果，重点是酒精自我管理期间复发和依赖。使用无效突变小鼠，我们将测试的假设，PKC β和γ差异调节酒精自我管理，并退出相关的变化，酒精自我管理，通过GABAA受体活性。 具体目标1将测试的假设，具体的PKC亚型差异调节酒精自我管理在反复复发期间通过GABA能机制。我们将首先检查操作性酒精自我管理的PKC β和γ无效突变小鼠和控制使用的模型，反复酒精剥夺，我们已经建立了小鼠。具体目标2将检查PKC β和γ缺陷小鼠中反复乙醇戒断癫痫发作的严重程度。目标3的研究将通过检查在反复依赖和戒断发作期间酒精自我给药的复发来扩展目标1和2的戒断结果。在每个目标的合作研究将检查多个脑区的GABAA受体亚基表达的变化，在膜部分的蛋白质印迹分析，MAPK/ERK信号和神经病理学（船员组成）。为了确认分子变化的功能相关性，我们将给予药理学药物（即，非选择性GABAA α拮抗剂氟马西尼或α 1选择性激动剂唑吡坦）。这些研究有望阐明剥夺或戒断后影响酒精自我管理的适应过程的分子机制。这些信息可能会导致识别新的药物治疗与酒精中毒相关的问题，如失控和复发的治疗。

DESCRIPTION (provided by applicant): The primary goal of this project is to understand molecular mechanisms that influence adaptive changes in alcohol self-administration and dependence that result from repeated alcohol exposure and withdrawal. Substantial evidence indicates that neuronal gamma-amino-butyric acid type A (GABAA) receptors modulate alcohol self- administration and alcohol withdrawal severity. Our research has shown that mutant mice lacking the epsilon isoform of protein kinase C (PKCepsilon) are supersensitive to acute alcohol and GABAA allosteric positive modulators. This supersensitivity is associated with reduced alcohol self-administration, absence of the alcohol deprivation effect (ADE), and lack of progression of ethanol withdrawal seizure severity. By contrast, PKCgamma null mutant mice are less sensitive to ethanol modulation of GABAA receptor function and drink more ethanol suggesting that specific isoforms of PKC may differentially modulate GABAA mediated effects of ethanol. The present proposal extends these findings by focusing on alcohol self-administration during relapse and dependence. Using null mutant mice, we will test the hypothesis that PKC epsilon and gamma differentially modulate alcohol self-administration, and withdrawal-related changes in alcohol self-administration, via GABAA receptor activity. Specific Aim 1 will test the hypothesis that specific PKC isoforms differentially modulate alcohol self-administration during repeated relapse via GABAergic mechanisms. We will first examine operant alcohol self-administration by PKC epsilon and gamma null mutant mice and controls using a model of repeated alcohol deprivation, which we have established in mice. Specific Aim 2 will examine repeated ethanol withdrawal seizure severity in PKC epsilon and gamma null mice. Studies of Aim 3 will extend the withdrawal findings of Aims 1 and 2 by examining relapse to alcohol self-administration during episodes of repeated dependence and withdrawal. Collaborative studies in each aim will examine multiple brain regions for changes in GABAA receptor subunit expression in the membrane fraction by Western Blot analysis, and MAPK/ERK signaling and neuropathology (Crews component). To confirm functional relevance of molecular changes, we will administer pharmacological agents (i.e., the nonselective GABAA alpha-antagonist flumazenil or the alpha1 selective agonist zolpidem) during repeated relapse and withdrawal. These studies are expected to elucidate molecular mechanisms of adaptive processes that influence alcohol self-administration after deprivation or withdrawal. This information might lead to the identification of novel pharmacological therapeutics for treatment of problems associated with alcoholism, such as loss of control and relapse.