The Alpha-1 GABAA Receptor Regulates Alcohol-Drinking Behaviors

描述（由申请人提供）：已经确定乙醇[EtOH]的奖励特性部分由GABA A受体机制介导;然而，最近的研究表明，a1受体亚基，特别是腹侧苍白球[VP]内的亚基，可能是调节EtOH强化的关键GABA能受体。本提案的主要目标是通过结合神经精神药理学和分子生物学技术，进一步评估含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[HAD-1]大鼠。待检验的主要假设是，选择性抑制HAD-1大鼠VP内含有GABAA α 1受体的亚基将导致EtOH激发行为的选择性减少，对蔗糖激发行为影响很小或没有影响。GABAA α 1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、转录后基因沉默机制。然后通过双侧引导插管将该载体直接输注到HAD-1大鼠的VP中。假设在将载体介导的siRNA扩增子输注到VP中后，将观察到EtOH维持的应答的选择性降低。具体而言，预期具有更好的和神经解剖学特异性，因为在VP中输注活性病毒后，既没有对蔗糖的抑制维持响应，也没有对酒精响应活性病毒输注到神经解剖学控制位点的抑制[例如，尾壳核]。在随后的研究中，将使用原位逆转录酶-PCR、免疫组织化学和Western分析[免疫印迹]的组合来确定HSV-siRNA病毒载体操作的成功。这些研究应该扩展我们对GABAA a1受体亚型在饮酒行为调节中的作用的理解。

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.