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: 6776927
• 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/6776927
• 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，与压力相关的神经激素、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）中的神经调节剂，在压力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，例如觉醒的增加和注意力的改变，因此可能具有适应性。然而，压力史改变了 LC 去甲肾上腺素能系统对 CRF 的敏感性，这可能是与压力相关的精神疾病的某些症状的基础（例如，过度兴奋、注意力不集中）。该提议将增进我们对 CRF 改变 LC 活性的细胞机制、应激诱导可塑性的机制以及可能影响认知的 CRF-LC 相互作用后果的理解。最近推出的针对 CRF-R1 受体的抗血清将用于表征和量化 CRF-R1 在 LC 内神经化学鉴定的细胞过程中的定位（AIM 1）。 CRF-R1 受体的内化和运输将在超微结构水平上对已在 LC 中施用 CRF 或已急性暴露于应激源的大鼠进行检查。 LC 活性的变化将与 CRF-R1 细胞易位 (AIM 2) 指数相关。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 敏感性突触后变化的细胞机制 (AIM 3)。其中包括 1) 逆转录酶聚合酶链式反应 (RT-PCR)，用于测量 LC 中 CRF 受体 mRNA 的变化，2) 蛋白质印迹分析，用于测量 LC 中 CRF 受体的蛋白质水平，以及与 CRF-R1 激活相关的信号级联组分的水平，以及 3) 受体内化和再循环的超微结构分析。最后，AIM 4 旨在确定 LC 去甲肾上腺素能系统的 CRF 调节对由对感觉刺激的注意力控制的前脑活动和行为的影响。在感觉刺激（胡须刺激）期间，LC 中的 CRF 对功能连接网络（胡须-桶状皮层）中神经元群活动的影响将被量化。此外，还将确定 LC 中 CRF 对胡须垫刺激控制的行为的影响。这些研究将共同​​促进我们对压力对 LC-去甲肾上腺素系统急性影响的细胞机制、压力诱导的该系统可塑性的机制以及该系统在压力认知反应中的作用的理解。