Brain Noradrenergic Neurons, Peptides and Stress

大脑去甲肾上腺素能神经元、肽和压力

• 批准号: 6916254
• 负责人: RITA VALENTINO
• 金额: $ 27.79万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-01-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6916254
• 关键词: behavior test; biological signal transduction; brain electrical activity; cognition; confocal scanning microscopy; corticotropin releasing factor; electron microscopy; electrophysiology; electrostimulus; glucocorticoids; hormone receptor; hormone regulation /control mechanism; laboratory rat; locus coeruleus; neural plasticity; neurotransmitters; norepinephrine; polymerase chain reaction; prosencephalon; protein localization; protein transport; receptor binding; somesthetic sensory cortex; stress; western blottings

DESCRIPTION (provided by applicant): Convergent findings suggest that the stress-related neurohormone, corticotropin-releasing factor (CRF) serves as a neuromodulator in the noradrenergic nucleus locus coeruleus (LC) to regulate the activity of this forebrain-projecting system during stress. CRF-induced LC activation may be important for cognitive aspects of the stress response, such as increased arousal and alterations in attention, and therefore may be adaptive. However, a history of stress alters the sensitivity of the LC-noradrenergic system to CRF and this may underlie certain symptoms of stress-related psychiatric disorders (e.g., hyperarousal, difficulty concentrating). This proposal will advance our understanding of the cellular mechanisms by which CRF alters LC activity, the mechanisms underlying stress-induced plasticity and consequences of CRF-LC interactions that may impact on cognition. An antiserum directed against the CRF-R1 receptor that has recently become available will be used to characterize and quantify the localization of CRF-R1 on neurochemically identified cellular processes within the LC (AIM 1). Internalization and trafficking of the CRF-R1 receptor will be examined at the ultrastructural level in rats that have been administered CRF in the LC or that have been acutely exposed to stressors. Changes in LC activity will be correlated to indices of CRF-R1 cellular translocation (AIM 2). A variety of approaches will be used to determine the cellular mechanisms underlying postsynaptic changes in LC sensitivity to CRF that are observed in rats with a history of stress (AIM 3). These include 1) reverse transcriptase-polymerase chain reaction (RT-PCR) to measure changes in CRF-receptor mRNA in the LC, 2) Western blot analysis to measure protein levels in the LC of CRF receptors, as well as levels of components of the signaling cascade linked to CRF-R1 activation, and 3) ultrastructural analysis of receptor internalization and recycling. Finally, AIM 4 is designed to determine the consequences of CRF modulation of the LC-noradrenergic system on forebrain activity and behavior controlled by attention to sensory stimuli. The effect of CRF in the LC on activity of ensembles of neurons in a functionally-connected network (whiskerpad-barrelfield cortex) during sensory stimulation (whiskerpad stimulation) will be quantified. Additionally, the effect of CRF in the LC on behavior controlled by whiskerpad stimulation will be determined. Together these studies will advance our understanding of the cellular mechanisms underlying the acute effects of stress on the LC-norepinephrine system, mechanisms underlying stress-induced plasticity of this system and the role of this system in cognitive responses to stress.

描述（由申请人提供）：一致的研究结果表明，应激相关神经激素促肾上腺皮质激素释放因子（CRF）作为去甲肾上腺素能蓝斑核（LC）中的神经调质，在应激期间调节该前脑投射系统的活动。CRF诱导的LC激活可能对应激反应的认知方面很重要，例如增加唤醒和注意力改变，因此可能是自适应的。然而，应激史改变了LC-去甲肾上腺素能系统对CRF的敏感性，这可能是应激相关精神障碍的某些症状的基础（例如，过度兴奋，难以集中注意力）。这一建议将推进我们的理解CRF改变LC活动的细胞机制，应激诱导的可塑性和CRF-LC相互作用可能影响认知的后果的机制。针对CRF-R1受体的抗血清，最近已成为可用的将被用来表征和量化的本地化的CRF-R1的神经化学确定的细胞过程中的LC（AIM 1）。在LC中给予CRF或急性暴露于应激物的大鼠中，将在超微结构水平检查CRF-R1受体的内化和运输。LC活性的变化将与CRF-R1细胞易位指数（AIM 2）相关。将使用多种方法来确定在有应激史的大鼠中观察到的LC对CRF的敏感性突触后变化的细胞机制（AIM 3）。这些包括1）逆转录酶-聚合酶链反应（RT-PCR），以测量LC中CRF受体mRNA的变化，2）Western印迹分析，以测量LC中CRF受体的蛋白水平，以及与CRF-R1活化相关的信号级联的组分水平，和3）受体内化和再循环的超微结构分析。最后，AIM 4旨在确定CRF调节LC-去甲肾上腺素能系统对前脑活动和由对感觉刺激的注意力控制的行为的后果。将量化感觉刺激（须垫刺激）期间LC中CRF对功能连接网络（须垫-桶场皮质）中神经元集合活性的影响。此外，将确定LC中CRF对由须垫刺激控制的行为的影响。总之，这些研究将推进我们的理解的细胞机制的应激对LC-去甲肾上腺素系统的急性效应，应激诱导的可塑性，该系统的机制和该系统在认知应激反应的作用。