Central Amygdala CART modulates ethanol withdrawal induced anxiety

描述（由申请人提供）：乙醇依赖是一种普遍的痛苦，每年的社会成本高达数千亿美元。酒精依赖的治疗是复杂的许多因素，最显着的复发。复发行为被认为是由乙醇戒断引起的焦虑（EWIA）。与EWIA密切相关的大脑区域是中央杏仁核（CeA）。中央杏仁核的病变导致戒断过程中乙醇消耗量减少，而基底外侧杏仁核的病变则没有。乙醇依赖引起的神经生物学改变是广泛的，在CeA，这些变化包括增加的谷氨酸能活性和NMDA受体表达。在戒断过程中，这些增加导致CeA的过度激活;这种过度激活被认为是介导戒断引起的焦虑的基础复发。皮质醇和安非他明调节的转录物（CART）是一种新的与乙醇依赖有关的神经肽。它在CeA中表达，并已显示在急性戒断期间增加此处的表达。此外，据报道，CART可增强NMDA受体介导的电流。这个建议的首要假设是，CART是EWIA的关键调解人。为了测试这一点，将进行依赖和戒断期间CART表达的全面检查。将使用两种模型诱导乙醇依赖：慢性乙醇处理（CET）和慢性间歇性乙醇（CIE）。CIE包含一个可能涉及戒断引起的焦虑的戒断成分。将使用CET和CIE两者比较野生型（WT）和CART敲除（KO）小鼠中的依赖性倾向。还将在停药0、24和72小时时对WT和KO小鼠进行EWIA检查。还将进行皮质酮ELISA和免疫组织化学。还将评估应激诱导的饮酒和响应于急性应激源的皮质酮水平，并在WT和KO小鼠之间进行比较。本提案的后半部分将首先在我们手中验证CART的NMDA增强作用，特别是在CeA中。然后，将进行全面的电生理电压钳分析，并比较WT和KO小鼠在停药0、24和72小时时未使用乙醇、CET和CIE小鼠CeA中NMDA受体介导的电流。这些实验的结果将阐明EWIA的基础和CART在EWIA诱导的复发中的作用。此外，这些结果将提供一个新的目标，治疗干预和预防复发的个人依赖于乙醇和可能的其他药物滥用。

DESCRIPTION (provided by applicant): Ethanol dependence is a widespread affliction with societal costs in the hundreds of billions of dollars every year. Treatment of ethanol dependence is complicated by many factors, most notably relapse. Relapse behaviors are believed to result from ethanol withdrawal-induced anxiety (EWIA). A brain region critically involved in EWIA is the central amygdala (CeA). Lesions of the central, but not basolateral, amygdala resulted in reduced ethanol consumption during withdrawal. Neurobiological alterations induced by ethanol dependence are widespread; in the CeA, these changes include increased glutamatergic activity and NMDA receptor expression. During withdrawal, these increases lead to hyperactivation of the CeA; this hyperactivation is believed to mediate the withdrawal-induced anxiety that underlies relapse. Cocaine- and amphetamine-regulated transcript (CART) is a novel neuropeptide implicatied in ethanol dependence. It is expressed in the CeA and has been shown to increase expression here during acute withdrawal. Additionally, CART, has been reported to potentiate NMDA receptor-mediated currents. The overarching hypothesis of this proposal is that CART is a critical mediator of EWIA. To test this, a comprehensive examination of CART expression during dependence and withdrawal will be conducted. Ethanol dependence will-be induced using two models: chronic ethanol treatment (CET) and chronic intermittent ethanol (CIE). CIE contains a withdrawal component that presumably involves withdrawal induced anxiety. Dependence liability in wild type (WT) and CART knockout (KO) mice will compared using both CET and CIE. An examination of EWIA in the WT and KO mice at 0, 24, and 72 hours withdrawal will also be conducted. Corticosterone ELISAs and immunohistochemistry will be performed as well. Stress induced drinking and corticosterone levles in response to an acute stressor will also be assessed and compared between the WT and KO mice. The second half of this proposal will first verify in our hands, the NMDA potentiating actions of CART, specifically in the CeA. Then, a comprehensive electrophysiological voltage clamp analysis and comparison of NMDA receptor-mediated currents in the CeA of ethanol naive, CET, and CIE mice at 0, 24, and 72 hours withdrawal in WT and KO mice will be performed. The findings from these experiments will elucidate the underpinnings of EWIA and the role of CART in EWIA-induced relapse. Furthermore, these results will provide a novel target for therapeutic intervention and prevention of relapse in individuals dependent on ethanol and possibly other drugs of abuse.