Dopaminergic Modulation of Excitatory Transmission in BNST and Regulation by Ethanol

BNST 中兴奋性传递的多巴胺能调节和乙醇的调节

• 批准号: 9793987
• 负责人: James Melchior
• 金额: $ 5.28万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9793987
• 关键词: Abstinence; Acute; Adaptive Behaviors; Adrenergic Receptor; Affect; Alcohol abuse; Alcohol consumption; Alcohol dependence; Alcohol withdrawal syndrome; Anxiety; Autoreceptors; Bathing; Behavior; Behavioral; Brain; Catecholamines; Cells; Characteristics; Chronic; Control Groups; Development; Dopamine; Dose; Electric Stimulation; Electrophysiology (science); Equilibrium; Ethanol; Event; Frequencies; Glutamates; Goals; Intoxication; Investigation; Measures; Mediating; Mediator of activation protein; Mental Depression; Modeling; Molecular; Mood Disorders; Motivation; Negative Reinforcements; Neuromodulator; Neurons; Norepinephrine; Optics; Output; Periodicity; Pharmaceutical Preparations; Pharmacology; Physiology; Positioning Attribute; Prevalence; Prevention; Progressive Disease; Receptor Activation; Regulation; Relapse; Rewards; Role; Scanning; Signal Transduction; Slice; Stress; Structure of terminal stria nuclei of preoptic region; Suggestion; Symptoms; Synapses; Synaptic Receptors; Synaptic Transmission; System; Techniques; Testing; Transgenic Mice; United States; Ventral Tegmental Area; Withdrawal; addiction; alcohol effect; alcohol exposure; alcohol seeking behavior; alcohol use disorder; anxiety states; anxiety-like behavior; behavioral response; beta-adrenergic receptor; dopaminergic neuron; economic cost; gamma-Aminobutyric Acid; insight; negative affect; nerve supply; noradrenergic; optogenetics; recruit; response; selective expression; stress state; stressor; synaptic function; temporal measurement; transmission process; uptake; vapor

Project Summary/Abstract Alcohol addiction is characterized by repeated relapses to alcohol abuse despite negative consequences. This counter-adaptive behavior is believed to result from adaptations in underlying neurocircuitry which occur in response to chronic alcohol abuse. These adaptations result in persistent negative affective states, during abstinence, which drive reinstatement of alcohol use as a means of negative reinforcement, or relief from negative conditions. The bed nucleus of the stria terminalis (BNST) is a key mediator of stress and anxiety states and behavioral responses to stressors. Models of stress-induced reinstatement of drug seeking have identified norepinephrine signaling in the BNST as critical to relapse behavior. Noradrenergic excitation of the BNST through β-adrenergic receptors promotes anxiety-like behaviors and drug reinstatement, whereas inhibition of BNST activity through α2-adrenergic receptors reduces anxiety-like behaviors. The BNST also receives prominent dopaminergic innervation from the ventral tegmental area (VTA). Investigations into the role of dopaminergic signaling in the BNST are relatively sparse and somewhat contradictory. For example, low doses of bath applied dopamine resulted in increased excitatory activity in the BNST, while high doses resulted in increased inhibitory actions. Further, the inhibitory actions are suggested to occur through dopamine cross-activation of α2-adrenergic receptors. In order to resolve these discrepancies, it is important to have a clear understanding of endogenous dopamine signals and how rapid changes in dopamine concentrations may selectively recruit post-synaptic receptor activation. Often, investigations of dopamine signaling use fast-scan cyclic voltammetry, which provides high temporal resolution of dopamine release and uptake in response to local electrical stimulation of terminals fields. However, in the BNST, dopamine and norepinephrine provide overlapping innervation, thus both catecholamines are released in response to local electrical stimulation, and cyclic voltammetry cannot distinguish between catecholamines. This hinders the use of this technique in assessing the potentially opposing roles of dopamine and norepinephrine signaling on BNST synaptic physiology. In this proposal we introduce a model in which we optogenetically target VTA dopamine neurons projecting to the BNST, such that we may use selective optical-stimulation of local dopamine release, measured with cyclic voltammetry, in BNST slices, ex vivo. Further, we propose to use optically-stimulated dopamine release in combination with whole cell electrophysiology to measure the cellular responses to endogenous dopamine signals. This ex vivo model allows us to employ various pharmacological manipulations to assess how dopamine signaling is integrated into synaptic physiology and to what degree endogenous dopamine signals recruit activation of α2-adrenergic receptors. Finally, we will examine how chronic intermittent ethanol vapor exposure alters the mechanisms of dopaminergic modulation of BNST synaptic function.

项目概要/摘要 酒精成瘾的特点是尽管有负面后果，但酒精滥用却反复复发。 反适应行为被认为是由潜在神经回路的适应引起的，这些适应发生在 对长期酗酒的反应会导致持续的负面情感状态。 戒酒，促使恢复饮酒作为负强化或缓解的一种手段 终纹床核（BNST）是压力和焦虑的关键调节因子。 对压力源的状态和行为反应模型。 确定 BNST 中的去甲肾上腺素信号对于去甲肾上腺素能兴奋的复发行为至关重要。 BNST 通过 β-肾上腺素能受体促进焦虑样行为和药物恢复，而 通过 α2 肾上腺素能受体抑制 BNST 活性也可减少焦虑样行为。 接受来自腹侧被盖区（VTA）的显着多巴胺能神经支配。 BNST 中多巴胺能信号传导的作用相对稀疏且有些矛盾。 低剂量的多巴胺浴会导致 BNST 的兴奋性活动增加，而高剂量的多巴胺会导致 BNST 的兴奋性活动增加。 导致抑制作用增强。此外，抑制作用被认为是通过以下方式发生的。 多巴胺对 α2 肾上腺素能受体的交叉激活 为了解决这些差异，重要的是。 清楚地了解内源性多巴胺信号以及多巴胺的快速变化 浓度可能选择性地招募突触后受体激活。 信号传导使用快速扫描循环伏安法，可提供多巴胺释放的高时间分辨率 然而，在 BNST 中，多巴胺和终端场的局部电刺激反应。 去甲肾上腺素提供重叠的神经支配，因此两种儿茶酚胺都会响应局部释放 电刺激和循环伏安法无法区分儿茶酚胺，这阻碍了使用。 该技术在评估多巴胺和去甲肾上腺素信号传导的潜在相反作用中的应用 BNST 突触生理学 在本提案中，我们引入了一个光遗传学目标 VTA 的模型。 多巴胺神经元投射到 BNST，这样我们就可以使用选择性光刺激局部 多巴胺释放，用循环伏安法测量，在 BNST 切片中，离体。 光刺激多巴胺释放结合全细胞电生理学来测量细胞 对内源性多巴胺信号的反应这种离体模型使我们能够采用各种药理学。 评估多巴胺信号传导如何整合到突触生理学中以及整合到什么程度的操作 最后，我们将研究内源性多巴胺信号如何激活 α2 肾上腺素受体。 慢性间歇性乙醇蒸气暴露改变了 BNST 的多巴胺能调节机制 突触功能。