CORTICOTROPIN RELEASING FACTOR/SEROTONERGIC INTERACTIONS

描述：（改编自申请人摘要） 促肾上腺皮质激素释放因子（CRF）和5-羟色胺（5-HT）系统具有 与压力相关的精神疾病有独立关联 我们证明了CRF对前脑5-HT释放的有效作用， 5-HT中缝背核（DRN）神经元的活性。采取 CRF神经支配和DRN中CRF受体表达的发现， 这些结果表明内源性CRF在DRN内起作用， 调节前脑5-HT功能。以下AIMS测试了这一点 假设通过表征CRF-5-HT相互作用， 超微结构、电生理和神经化学水平， 确定参与这些相互作用的条件，并确定 DRN内的CRF效应是否在与DRN相关的行为中发挥作用， 抑郁症1)描述和量化CRF对 终末区细胞外5-HT水平和DRN神经元活性。 将生成CRF效应的剂量-反应曲线（给药 i. c. v.或intraraphe）对外侧隔、杏仁核和 皮质和DRN神经元活动。CRF拮抗剂的疗效 （i. c. v.给药，全身或髓内），以防止这些 效果将被确定。这一目标将揭示CRF是否起作用 直接在DRN内改变前脑5-HT释放，是否影响 对5-HT释放的影响具有区域特异性， 2）确定内源性的生理条件， CRF对DRN-5-HT系统的影响CRF拮抗剂的能力 （i. c. v.或缝内给药），以防止前脑5-HT 将确定由不同挑战引起的释放。这一目标 将揭示CRF-5-HT相互作用的条件; 3)表征DRN中CRF-5-HT相互作用的细胞底物 并识别DRN的CRF传入。CRF之间的相互作用 终端和5-HT过程中的DRN将可视化在 超微结构水平采用双标记免疫组织化学和电子显微镜 显微镜神经束示踪将用于识别CRF DRN的传入神经这一目的将揭示潜在的细胞机制 潜在的CRF-5-HT相互作用，并提供详细说明CRF如何 系统与DRN的联系; 4）阐明CRF-5-HT相互作用的作用 与抑郁症有关的行为。假设CRF 在DRN中释放，随后抑制5-HT前脑释放 与游泳压力相关的潜在行为不动性将是 测试. CRF或CRF拮抗剂（i. c. v.或 在强迫游泳试验中的行为将被确定。这 目的揭示CRF-5 HT的潜在病理生理学后果 交互.

DESCRIPTION: (Adapted From The Applicant's Abstract) Corticotropin-releasing factor (CRF) and serotonin (5-HT) systems have been independently implicated in stress-related psychiatric disorders. We demonstrate potent effects of CRF on forebrain 5-HT release and activity of putative 5-HT dorsal raphe nucleus (DRN) neurons. Taken with findings of CRF innervation and expression of CRF receptors in the DRN, these results suggest that endogenous CRF acts within the DRN to regulate forebrain 5-HT function. The following AIMS test this hypothesis by characterizing CRF-5-HT interactions at an ultrastructural, electrophysiological and neurochemical level, identifying conditions that engage these interactions, and determining whether CRF effects within the DRN play a role in a behavior associated with depression. 1) Characterize and quantify CRF effects on extracellular 5-HT levels in terminal regions and DRN neuronal activity. Dose-response curves will be generated for CRF effects (administered i.c.v. or intraraphe) on 5-HT release in lateral septum, amygdala and cortex and DRN neuronal activity. The efficacy of CRF antagonists (administered i.c.v., systemically or intraraphe) to prevent these effects will be determined. This AIM will reveal whether CRF acts directly within the DRN to alter forebrain 5-HT release, whether effects on 5-HT release are regionally specific and the CRF receptor subtype involved; 2) Identify physiological conditions during which endogenous CRF impacts on DRN-5-HT systems. The ability of CRF antagonists (administered i.c.v. or intraraphe) to prevent changes in forebrain 5-HT release elicited by different challenges will be determined. This AIM will reveal conditions during which CRF-5-HT interactions are engaged; 3) Characterize cellular substrates for CRF-5-HT interactions in the DRN and identify CRF afferents to the DRN. Interactions between CRF terminals and 5-HT processes in the DRN will be visualized at the ultrastructural level using dual label immunohistochemistry and electron microscopy. Neuronal tract tracing will be used to identify CRF afferents to the DRN. This AIM will reveal potential cellular mechanisms underlying CRF-5-HT interactions and provide a map detailing how CRF systems link to the DRN; 4) Elucidate the role of CRF-5-HT interactions in a behavior associated with depression. The hypothesis that CRF release in the DRN and subsequent inhibition of 5-HT forebrain release underlie behavioral immobility associated with swim stress will be tested. The effects of CRF or CRF antagonists (administered i.c.v. or intraraphe) on behavior in the forced swim test will be determined. This AIM will reveal potential pathophysiological consequences of CRF-5HT interactions.