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

描述(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酒精滥用方面起着重要作用。在大鼠中，慢性乙醇之前的重复应激会敏化戒断诱导的焦虑。在青春期和成年大鼠脑内应激增加细胞因子的基础上，对青春期和成年大鼠的初步研究表明，每周重复给予脂多糖(LPS)以增加脑内细胞因子，然后5天乙醇(LPS/戒断方案)敏化戒断诱导的焦虑，并在戒断3天后增加脑内14-GABA(A)受体亚单位。这一努力支持了细胞因子参与了应激增强乙醇诱导的适应性变化的作用的结论。因此，对青春期大鼠的研究将首先描述在内毒素/戒断方案期间和之后皮质中14个亚单位变化的时间进程。随后，将确定这14个亚基的增加是否伴随着11、15、32和4个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)受体的功能，将进行电生理研究，以测试在内毒素/撤退方案后，突触和突触外GABA功能是否发生较长时间的变化。此外，还将进行药理学研究，以确定选定大脑区域中这些细胞位置的选定GABA(A)受体亚单位。最后，将进行研究，以确定阻断内毒素/戒断方案诱导的乙醇戒断引起的焦虑的敏化是否会阻止GABA(A)受体亚单位的适应性变化，并减少突触和突触外部位的电生理变化。后一种策略将通过预防内毒素/戒断方案对酒精戒断诱导的焦虑的行为敏化来实现，方法是在酒精暴露前每周注射一次脂多糖之前，给予阻断这种敏化的药物。本工作将验证这样一种假设，即内毒素/戒断方案诱导青春期大鼠GABA(A)受体功能的持续适应以及突触和突触外部位的功能变化将与该方案诱导的戒断诱导焦虑的敏化相关。收集的数据应该为理解细胞因子在压力支持功能病理中的作用提供基础，这种功能病理增加了青少年成年后对持续酗酒的易感性。与公共健康相关青春期的墨水会增加成年后酗酒的可能性。此外，压力是持续酗酒的一个重要方面。由于细胞因子对应激反应有贡献，这项建议研究了由细胞因子和乙醇相互作用导致的青春期大鼠的适应性变化。

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.