The Ethanol - Anxiety Interaction: Cellular Mechanisms

描述（由申请人提供）：在人类和实验动物模型中，乙醇消费的焦虑特性和慢性暴露戒断的焦虑方面都得到了很好的证实。因为这些与焦虑相关的影响有助于加强酒精滥用，所以详细了解乙醇-焦虑相互作用的细胞和分子机制是很重要的。虽然已知在恐惧/焦虑期间，许多大脑区域会相互作用，但杏仁核是前脑边缘的“情绪”中心，是神经焦虑回路的核心组成部分。兴奋性和抑制性神经递质系统之间的微妙平衡控制着这一系统，杏仁核兴奋的增加导致恐惧/焦虑的增强。使用急性分离的外侧/基底外侧杏仁核神经元的初步研究表明，慢性乙醇可以改变nmda型嗜离子性谷氨酸和抑制GABAA受体功能，同时保留其他神经递质系统。重要的是，这两个受体系统都对临床相关的乙醇浓度敏感，这表明它们在慢性暴露期间的功能适应可能是与焦虑滥用相关的细胞底物之一。我们的中心假设，即慢性乙醇暴露和随后的戒断对杏仁核主要神经递质系统有不同的影响，将通过进一步检查大鼠外侧/基底外侧杏仁核内谷氨酸门控嗜离子受体和GABAA受体的表达和功能来验证。具体来说，我们将利用全细胞膜片钳电生理学和单细胞逆转录/聚合酶链反应（RT-PCR）对急性分离的神经元进行处理。这些研究将与实时RT-PCR一起进行，以表征外侧/基底外侧杏仁核对慢性乙醇暴露和戒断的细胞和分子适应。我们还将在体外切片制备中，通过使用外侧/基底外侧杏仁核的全细胞记录测量突触后和突触前功能，来评估对慢性乙醇暴露的适应的生理后果。最后，我们将通过在戒断过程中整合细胞、分子、突触和行为测量来测试受体/突触功能、焦虑和戒断之间的关系。总之，这些研究将为慢性乙醇诱导的与恐惧/焦虑相关的适应的相关机制提供重要的见解，并最终导致更好地理解乙醇-焦虑的相互作用。

DESCRIPTION (provided by applicant): The anxiolytic properties of ethanol consumption and anxiogenic aspects of withdrawal from chronic exposure are well established in both humans as well as experimental animal models. Because these anxiety-related effects help potentiate alcohol abuse, it is important to gain a detailed understanding of the cellular and molecular mechanisms that underlie the ethanol-anxiety interaction. While numerous brain regions are known to interact during fear/anxiety, the amygdala, an "emotional" center in the limbic forebrain, is a central component of the neural anxiety circuitry. A delicate balance between excitatory and inhibitory neurotransmitter systems controls this system, with increases in amygdala excitation leading to enhanced fear/anxiety. Preliminary studies of using acutely isolated neurons from the lateral/basolateral amygdala indicate that chronic ethanol can alter NMDA-type ionotropic glutamate and inhibitory GABAA receptor function while sparing other neurotransmitter systems. Importantly, both receptor systems are sensitive to clinically relevant ethanol concentrations, indicating their functional adaptation during chronic exposure may be among the cellular substrates relating abuse with anxiety. Our central hypothesis, that chronic ethanol exposure and subsequent withdrawal differentially affect major amygdala neurotransmitter systems, will be tested by further examination of glutamate-gated ionotropic receptor and GABAA receptor expression and function within the rat lateral/basolateral amygdala. Specifically, we will utilize whole-cell patch clamp electrophysiology and single-cell reverse transcription/polymerase chain reaction (RT-PCR) with acutely isolated neurons. These studies will be done along with real-time RT-PCR to characterize cellular and molecular adaptations in the lateral/basolateral amygdala to chronic ethanol exposure and withdrawal. We will also assess the physiological ramifications of adaptations to chronic ethanol exposure by measuring post- and pre-synaptic function using whole-cell recordings within lateral/basolateral amygdala in in vitro slice preparations. Finally, we will test the association between receptor/synaptic function, anxiety, and withdrawal by integrating cellular, molecular, synaptic and behavioral measures during a withdrawal time course. Together, these studies will provide important insight into the mechanisms associated with chronic ethanol-induced adaptations related to fear/anxiety and eventually lead to a better understanding of the ethanol-anxiety interaction.