Stress and alcohol drinking: early life dysregulation of neuropeptides

描述（由申请人提供）：压力和饮酒之间的联系是复杂的，但一些关键的神经适应在压力途径开始被理解。目前的提议探索了早期生活压力如何使小鼠在成年后容易过度饮酒的神经基质。大脑中的应激神经肽促肾上腺皮质激素释放因子（CRF）是一种可以被破坏的有趣神经肽。CRF可能是社交饮酒者中一种重要的调节激素，但在酒精依赖过程中可能出现CRF功能障碍。CRF可以在不同的大脑结构中发现，如腹侧被盖区（VTA）。VTA是一个可以发出药物奖励特性信号的位置，并通过神经递质多巴胺（DA）传达压力。CRF网络的失调可能是影响由压力驱动的饮酒的关键。为了严格检验这些理论，研究人员可以在小鼠中使用母亲分离压力（MSS）来诱导神经适应，以增加成年后的饮酒。在第一组实验中，小鼠幼崽每天与母鼠分离3小时，持续2周。成年后，小鼠被间歇性地接触酒精，这是一种测试自愿饮酒升级的有利方法。然后，我们将测量使用CRF-R1拮抗剂进入VTA的药理学治疗是否可以防止应力改变的DA冲动流加剧。在应激小鼠与非应激小鼠的前额叶皮层（VTA的末端区域）中，通过微透析测量饮酒导致的DA变化。大脑中的CRF蛋白也将在MSS和饮酒后被测量。在第二组实验中，研究人员测试了前脑CRF-R1的遗传预防是否会影响饮酒。前脑缺乏CRF-R1基因转录的小鼠也接受MSS、饮酒和透析来评估DA输出。最终，这些方法允许位点特异性操作来研究应力升级行为中VTA-PFC通路的CRF调节。药理学和遗传学方法不仅相互补充，而且还允许相当大的训练潜力。总之，确定压力升级饮酒的关键途径将促进对转变为酗酒背后机制的科学理解。拟议实验的结果可能揭示了基因和社会环境之间的相互作用，这些相互作用将社会用途与过度饮酒区分开来。最终，针对酒精使用障碍的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.