The Alpha-1 GABAA Receptor Regulates Alcohol-Drinking Behaviors

描述（由申请人提供）：已经确定乙醇[EtOH]的有益特性部分是由gabaa受体机制介导的；然而，直到最近才有研究表明，a1受体亚基，特别是腹侧pallidum [VP]中的a1受体亚基，可能是调节EtOH强化的关键gaba能受体。本研究的主要目的是通过神经精神药理学和分子生物学技术的结合，进一步评估GABAA a1受体亚基在调节etoh寻求行为中的作用。为了实现这一目标，将使用选择性繁殖的高饮酒量[hd -1]大鼠。要验证的主要假设是，对HAD-1大鼠VP中含有亚基的GABAA a1受体的选择性抑制将导致etoh动机行为的选择性减少，而对蔗糖动机行为的影响很小或没有影响。GABAA a1亚基的抑制将通过构建单纯疱疹病毒（HSV）载体来实现，该载体将利用siRNA序列特异性的转录后基因沉默机制。然后将该载体通过双侧引导管直接注入HAD-1大鼠VP。假设将载体介导的siRNA扩增子注入VP后，将观察到etoh维持的应答选择性降低。具体来说，强化物和神经解剖学特异性将被期待，因为在VP中注入活性病毒后，蔗糖抑制既不能维持反应，活性病毒注入神经解剖学控制位点（如尾状壳核）后，酒精抑制也不能维持反应。在随后的研究中，将结合原位逆转录- pcr、免疫组织化学和免疫印迹分析来确定HSV-siRNA病毒载体操作的成功。这些研究应该扩展我们对GABAA a1受体亚型在调节饮酒行为中的作用的理解。

DESCRIPTION (provided by applicant): It is well established that the rewarding properties of ethanol [EtOH] are mediated in part by GABAA-receptor mechanisms; however, only recently has research demonstrated that the a1 receptor subunit, particularly those within the ventral pallidum [VP], may be the critical GABAergic receptor regulating EtOH reinforcement. The primary objective of this proposal will be to further evaluate the role of the GABAA a1-containing receptor subunit in regulating EtOH-seeking behaviors by employing a combination of neuropsychopharmacological and molecular biology techniques. To accomplish this goal, the selectively-bred high alcohol-drinking [HAD-1] rats will be used. The primary hypothesis to be tested is that a selective inhibition of the GABAA a1 receptor containing subunit within the VP of HAD-1 rats will lead to selective reductions in EtOH-motivated behavior, with little or no effect on sucrose-motivated behaviors. The inhibition of the GABAA a1 subunit will be accomplished by constructing a herpes simplex virus [HSV] vector, which will utilize the siRNA sequence specific, posttranscriptional gene silencing mechanism. This vector will then be infused directly into the VP of HAD-1 rats via bilateral guide cannulae. It is hypothesized that a selective reduction in EtOH-maintained responding will be observed following infusion of the vector-mediated siRNA amplicon into the VP. Specifically, reinforcer and neuroanatomical specificity will be expected, as neither suppression on sucrose maintained responding following infusion of the active virus in the VP, nor suppression on alcohol responding infusion of the active virus into the neuroanatomical control locus [e.g., caudate putamen] will be expected. In subsequent studies, a combination of in situ reverse transcriptase-PCR, immunohistochemistry, and Western analyses [immunoblotting] will be used to determine the success of the HSV-siRNA viral vector manipulations. These studies should extend our understanding of the role of the GABAA a1 receptor subtype in the regulation of alcohol-drinking behaviors.