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

描述（由申请人提供）：青春期饮酒会增加成年后酗酒的可能性。同样，压力已被证明在维持酗酒方面发挥着重要作用。在大鼠中，长期乙醇摄入之前的反复压力会使戒断引起的焦虑变得敏感。基于应激会增加青少年和成年大鼠大脑中的细胞因子，对青少年和成年大鼠的初步研究表明，每周重复服用脂多糖（LPS）以增加大脑中的细胞因子，然后连续 5 天乙醇（LPS/戒断方案）可以使戒断诱发的焦虑变得敏感，并在戒断后 3 天增加大脑中的 14-GABA(A) 受体亚基。这项工作支持这样的结论：细胞因子有助于应激作用，增强乙醇诱导的适应性变化。因此，对青春期大鼠的研究将首先表征 LPS/戒断方案期间和之后皮质 14 亚基变化的时间过程。随后，将确定 14 亚基的增加是否伴随着 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，这些评估将在大脑的其他区域进行，包括海马体、丘脑和杏仁核。为了检查 GABA(A) 受体功能，将进行电生理学研究，以测试在 LPS/戒断方案后的较长时间内突触和突触外 GABA 功能是否发生变化。此外，还将进行药理学研究，以确定选定大脑区域的这些细胞位点上选定的 GABA(A) 受体亚基。最后，将进行研究以确定阻断 LPS/戒断方案引起的乙醇戒断引起的焦虑的敏化是否会阻止 GABA(A) 受体亚基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每周注射 LPS 剂量之前给予阻断这种敏化的药物来预防乙醇戒断引起的焦虑的 LPS/戒断方案行为敏化来实现。这项工作将检验以下假设：LPS/戒断方案诱导的 GABA(A) 受体功能持续适应以及青少年大鼠突触和突触外部位的功能变化将与该方案引起的戒断诱发焦虑的敏化相关。收集的数据应为理解细胞因子在功能病理学压力支持中的作用奠定基础，而功能病理学会增加青少年成年后继续酗酒的易感性。公共健康相关性 青春期的墨水会增加成年后成为酗酒者的可能性。此外，压力是导致酗酒复发的一个重要因素。由于细胞因子有助于应激反应，因此该提案检查了青春期大鼠因细胞因子和乙醇相互作用而产生的适应性变化。

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.