Neuroplasticity of the Extended Amygdala CRF circuitry in alcohol dependence

描述(申请人提供)：最近的研究强调了杏仁中央核(CEA)和促肾上腺皮质激素释放因子(CRF)系统在酒精依赖发展中的作用。特别是，CRF 1型受体(CRF1)拮抗剂阻断了应激源和乙醇戒断所产生的焦虑效应和乙醇自身给药的增加。值得注意的是，慢性CRF1拮抗可消除慢性间歇性乙醇暴露大鼠因依赖而导致的饮酒升级。我们证实，急性乙醇和CRF通过激活CRF1增加小鼠和大鼠CEA的GABA能传递，CRF和CRF1拮抗剂对乙醇依赖大鼠CEA神经元的GABA能传递的影响增强。然而，CEA是由不同类型的细胞组成的，技术上的限制阻碍了对从中获得记录的神经元的识别和进一步表征。因此，尽管在CRF1介导的急性和慢性乙醇对大脑区域的影响方面积累了大量的知识，但潜在的局部神经元微电路需要被描绘出来。因此，在这项研究中，我们将使用在表达CRF1的神经元中表达绿色荧光蛋白(GFP)的新型转基因小鼠模型(CRF1：GFP小鼠)来比较表达CEA CRF1的神经元和未标记神经元的电生理、神经化学、形态和生物学特性。使用电生理学结合组织化学和神经示踪方法，我们将获得关于这些神经元的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械性的见解。Contet博士和Mandyam博士是本次研究的关键人员，他们拥有完成这样一个多学科项目所需的所有必要专业知识。更好地了解酒精效应背后的分子机制以及影响CRF神经回路的神经适应对酒精依赖的研究人员来说是一个挑战，将有助于发现新的治疗药物来缓解酒精中毒。

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.