GABAA R-subunit changes in adolescents by a cytokine/ethanol withdrawal protocol

描述（由申请人提供）：在青春期饮酒会增加成年后酗酒的可能性。同样，压力已被证明在持续酗酒方面起着重要作用。在大鼠中，反复强调之前，慢性乙醇致敏戒断引起的焦虑。基于应激增加青少年和成年大鼠脑中的细胞因子，对青少年和成年大鼠的初步研究表明，每周重复给予脂多糖（LPS）以增加脑中的细胞因子，随后给予5天乙醇（LPS/戒断方案）使戒断诱导的焦虑敏化，并在戒断后3天增加脑中的14-GABA（A）受体亚单位。这项工作支持的结论是，细胞因子有助于应力的行动，以提高适应性变化诱导的乙醇。因此，在青春期大鼠中的研究将首先表征LPS/戒断方案期间和之后皮质中14个亚基变化的时间过程。随后，将确定14亚基的这种增加是否伴随着11、15、32和4 GABA（A）受体亚基的变化。为了评估这种适应性变化是否具有区域特异性，将在大脑的其他区域（包括海马体、丘脑和杏仁核）进行这些评估。为了检查GABA（A）受体功能，将进行电生理学研究以测试在LPS/戒断方案后突触和突触外GABA功能的变化是否持续较长时间。此外，将进行药理学研究，以确定选定的GABA（A）受体亚单位在这些细胞位点在选定的大脑区域。最后，将进行研究以确定是否阻断由LPS/戒断方案诱导的乙醇戒断诱导的焦虑的敏化将防止GABA（A）受体亚单位的适应性变化并减少突触和突触外位点的电生理变化。后一种策略将通过在乙醇暴露前注射每周一次的LPS剂量之前给予阻断这种致敏作用的药物来预防乙醇戒断诱导的焦虑的LPS/戒断方案行为致敏作用来实现。这项工作将检验这样一个假设，即LPS/戒断方案诱导的GABA（A）受体功能的持续适应以及青春期大鼠突触和突触外部位的功能变化与该方案诱导的戒断诱导焦虑的致敏性相关。收集的数据应该提供一个基础，了解的作用细胞因子有助于压力支持的功能性病理，增加青少年的易感性，继续酗酒的成年人。青少年时期的墨水增加了成年后酗酒的可能性。此外，压力是维持复发饮酒的一个重要方面。由于细胞因子有助于应激反应，本建议探讨适应性变化，在青春期大鼠的细胞因子和乙醇的相互作用的结果。

DESCRIPTION (provided by applicant): Drinking during adolescence enhances the probability of alcoholism upon reaching adulthood. Likewise, stress has been demonstrated to have an important role in sustaining alcohol abuse. In rats, repeated stresses prior to chronic ethanol sensitized withdrawal-induced anxiety. Based upon stress increasing cytokines in brain in adolescent and adult rats, preliminary research in adolescent and adult rats demonstrated that repeated weekly lipopolysaccharide (LPS) dosing to increase cytokines in brain followed by 5 days of ethanol (LPS/withdrawal protocol) sensitized withdrawal- induced anxiety and increased the 14-GABA(A) receptor subunit in brain 3 days after withdrawal. This effort supports the conclusion that cytokines contribute to the action of stress to enhance adaptive change induced by ethanol. Therefore, studies in adolescent rats will first characterize the time course of the 14 subunit change in cortex during and after the LPS/withdrawal protocol. Subsequently, it will be determine if this increase in the 14 subunit is accompanied by changes in 11, 15, 32, & 4 GABA(A) receptor subunits. To assess if this adaptive change has regional specificity, these assessments will be made in other regions of brain including the hippocampus, thalamus, and amygdala. To examine GABA(A) receptor function, electrophysiological studies will be performed to test if changes in synaptic and extrasynaptic GABA function occur for an extended period after the LPS/withdrawal protocol. Additionally, pharmacological studies will be carried out to identify selected GABA(A) receptor subunits at these cellular sites in chosen brain regions. Finally, studies will be undertaken to determine if blocking sensitization of ethanol withdrawal-induced anxiety induced by the LPS/withdrawal protocol will prevent the adaptive change in GABA(A) receptor subunits and diminish electrophysiological changes at synaptic and extrasynaptic sites. This latter strategy will be accomplished by preventing the LPS/withdrawal protocol behavioral sensitization of ethanol withdrawal-induced anxiety by administering drugs that block this sensitization when given prior to each of the weekly LPS doses injected before ethanol exposure. This work will test the hypothesis that the LPS/withdrawal protocol induction of persistent adaptation in GABA(A) receptor function and functional changes at synaptic and extrasynaptic sites in adolescent rats will correlate with the sensitization of withdrawal-induced anxiety induced by this protocol. The data collected should provide a foundation for understanding the role cytokines contribute to stress support of the functional pathology that increases adolescent susceptibility to continued alcohol abuse as adults. PUBLIC HEALTH RELEVANCE inking during adolescence enhances the probability of being an alcoholic during adulthood. Additionally, stress is an important aspect of sustaining relapse to drinking. Since cytokines contribute to stress responses, this proposal examines adaptive changes in adolescent rats that result from an interaction of cytokines and ethanol.