Neuroplasticity of the Extended Amygdala CRF circuitry in alcohol dependence

描述（由申请人提供）：最近的研究强调了杏仁核中央核（CeA）和促肾上腺皮质激素释放因子（CRF）系统的募集在乙醇依赖发展中的作用。特别是，CRF1型受体（CRF1）拮抗剂可阻断应激源和乙醇戒断产生的焦虑效应和乙醇自我给药量的增加。值得注意的是，慢性CRF1拮抗剂可消除暴露于慢性间歇乙醇的大鼠的依赖诱导的乙醇饮用增加。我们证明了急性乙醇和CRF通过激活CRF1增加小鼠和大鼠CeA中gaba能的传递，并且CRF和CRF1拮抗剂对乙醇依赖大鼠CeA神经元中gaba能传递的影响增强。然而，CeA由异质细胞类型组成，技术限制阻碍了对获得记录的神经元的鉴定和进一步表征。因此，尽管对crf1介导的急性和慢性乙醇在该脑区域的影响已经积累了大量的知识，但潜在的局部神经元微电路需要被描绘出来。因此，在本研究计划中，我们将使用一种创新的转基因小鼠模型（CRF1:GFP小鼠）在表达CRF1的神经元中表达绿色荧光蛋白（GFP），比较表达CeA CRF1的神经元与未标记的神经元的电生理、神经化学、形态学和药理特性。利用电生理学结合组织化学和神经示踪方法，我们将获得有关这些神经元功能和连通性的新信息，从而为CRF系统在酒精依赖发展中的作用提供机制见解。Drs。Contet和Mandyam是参与本研究的主要人员，他们拥有完成这一多学科项目所需的所有必要专门知识。更好地理解乙醇效应的分子机制和乙醇依赖中形成CRF神经回路的神经适应性对酒精研究人员来说是一个挑战，并将有助于发现新的治疗药物来减轻酒精中毒。

DESCRIPTION (provided by applicant): Recent research has highlighted the role of the central nucleus of the amygdala (CeA) and the recruitment of the corticotropin-releasing factor (CRF) system in the development of ethanol dependence. Particularly, CRF type 1 receptor (CRF1) antagonists block the anxiogenic effects and the increase in ethanol self-administration produced by stressors and ethanol withdrawal. Notably, chronic CRF1 antagonism abolishes dependence-induced escalation of ethanol drinking in rats exposed to chronic intermittent ethanol. We demonstrated that acute ethanol and CRF increase GABAergic transmission in mouse and rat CeA via CRF1 activation, and the effects of CRF and CRF1 antagonists on GABAergic transmission are enhanced in CeA neurons from ethanol-dependent rats. However, the CeA is comprised of heterogeneous cell types and technical limitations have precluded the identification and further characterization of neurons from which recordings were obtained. Thus, despite the vast knowledge accumulated on the CRF1-mediated effects of acute and chronic ethanol in this brain region, the underlying local neuronal microcircuitry needs to be delineated. Thus, in this research proposal we will use an innovative transgenic mouse model expressing green fluorescent protein (GFP) in neurons expressing CRF1 (CRF1:GFP mice) to compare the electrophysiological, neurochemical, morphological and hodological properties of CeA CRF1-expressing neurons to those of unlabeled neurons. Using electrophysiology in combination with histochemical and neurotracing methods, we will obtain novel information on functionality and connectivity of these neurons, thereby providing mechanistic insights into the role of the CRF system in the development of alcohol dependence. Drs. Contet and Mandyam, key personnel involved in the present study, possess all the necessary expertise needed to accomplish such a multidisciplinary project. A better understanding of the molecular mechanisms underlying ethanol effects and the neuroadaptations shaping the CRF neurocircuitry involved in ethanol-dependence represent a challenge to alcohol researchers and will be useful toward uncovering new therapeutic agents to alleviate alcoholism.