Stress and alcohol drinking: early life dysregulation of neuropeptides

描述(申请人提供)：压力和饮酒之间的联系是复杂的，但压力通路中的一些关键的神经适应开始被理解。目前的提案探索了早期生活压力如何使小鼠在成年后容易受到过量饮酒的神经基础。一种有趣的可以被破坏的神经肽是大脑中的应激神经肽促肾上腺皮质激素释放因子(CRF)。CRF可能是社交饮酒者的一种重要的调节激素，但CRF的功能障碍可能是在酒精依赖过程中发生的。CRF可以在不同的大脑结构中找到，比如腹侧被盖区(VTA)。VTA是一个可以通过神经递质多巴胺(DA)传递药物有益特性和传递压力的部位。CRF网络的失调可能是影响由压力驱动的饮酒的关键。为了批判性地检验这些理论，研究人员可以使用小鼠的母体分离应激(MSS)来诱导神经适应，以增加成年后的饮酒。在第一组实验中，小鼠从母亲的照料中分离出来，每天3小时，持续2周。成年后，小鼠被给予间歇性饮酒机会，这是测试自愿饮酒升级的一种有利方法。然后，我们将测量使用CRF-R1拮抗剂进入VTA的药物治疗是否可以防止因应激改变而加剧的DA脉冲流。应激小鼠与非应激小鼠的前额叶皮质(VTA的终末区域)的微透析法测量了饮酒后DA的变化。大脑中的CRF蛋白也将在MSS后和饮酒升级后进行测量。在第二组实验中，研究人员测试前脑CRF-R1的基因预防是否会影响饮酒。前脑中缺乏CRF-R1基因转录本的小鼠也接受MSS、饮酒和透析以评估DA的输出。最终，这些方法允许特定部位的操纵来研究CRF在应激升级行为中对VTA-PFC通路的调节。药理学和遗传学方法不仅相辅相成，而且还允许相当大的培训潜力。总之，识别压力增加饮酒的关键途径将促进对酒精中毒转变背后的机制的科学理解。拟议中的实验结果可能会揭示基因和社会环境之间的相互作用，从而将社交用途与过度饮酒区分开来。最终，酒精使用障碍的靶向治疗可能包括药物治疗和早期生活压力的管理。

DESCRIPTION (provided by applicant): The link between stress and alcohol drinking is complex, but some crucial neuroadaptations in stress pathways are beginning to be understood. The current proposal explores the neural substrates of how early life stress renders mice vulnerable to excessive alcohol drinking in adulthood. One interesting neuropeptide that can be disrupted is the stress neuropeptide corticotropin-releasing factor (CRF) in the brain. CRF may be an important regulatory hormone in social alcohol drinkers, but it is the dysfunction of CRF that may develop during alcohol dependence. CRF can be found in distinct brain structures, like the ventral tegmental area (VTA). The VTA is one site that can signal for the rewarding properties of drugs and communicate stress through the neurotransmitter dopamine (DA). The dysregulation of the CRF network may be crucial to influencing alcohol drinking driven by stress. To critically examine these theories, researchers can use maternal separation stress (MSS) in mice to induce neuroadaptations to increase alcohol drinking in adulthood. In the first set of experiments, mouse pups are separated from maternal care for 3 hours per day for 2 weeks. Later in adulthood, mice are given intermittent access to alcohol, an advantageous method to test escalated voluntary alcohol drinking. We will then measure if pharmacological treatment with CRF-R1 antagonists into the VTA can prevent intensified stress-altered DA impulse flow. Changes in DA as a result of alcohol drinking are measured with microdialysis in the prefrontal cortex (PFC), a terminal region of the VTA, in stressed mice vs. unstressed mice. CRF protein in the brain will also be measured after MSS and after escalated alcohol drinking. In a second group of experiments, researchers test if genetic prevention of forebrain CRF-R1 can influence alcohol drinking. Mice lacking CRF-R1 gene transcript in the forebrain also undergo MSS, alcohol drinking, and dialysis to assess DA output. Ultimately, these methods allow for site-specific manipulations to study CRF modulation of the VTA-PFC pathway in stress-escalated behavior. The pharmacological and genetic approaches not only complement each other, but also allow for considerable training potential. Altogether, identifying the crucial pathways in stress-escalated drinking would advance scientific understanding of the mechanisms behind the transition to alcoholism. Findings from the proposed experiments may reveal those interactions between genes and the social environment that differentiates social use from excessive drinking. Ultimately, targeted treatment for alcohol use disorders may include pharmacotherapy and management of early life stress.