CORTICOTROPIN RELEASING FACTOR/SEROTONERGIC INTERACTIONS

描述：(改编自申请人的摘要) 促肾上腺皮质激素释放因子(CRF)和5-羟色胺(5-HT)系统 与压力相关的精神障碍有独立牵连。 我们证明了CRF对前脑5-羟色胺释放和 5-羟色胺中缝背核(DRN)神经元的活动。随心所欲 CRF神经支配和CRF受体在DRN的表达 这些结果表明，内源性CRF在DRN内起作用 调节前脑5-羟色胺功能。以下目标验证了这一点 通过表征CRF-5-HT相互作用提出的假说 超微结构、电生理和神经化学水平， 确定参与这些交互的条件，并确定 DRN内的CRF效应是否在相关行为中发挥作用 患有抑郁症。1)表征和量化CRF对 终末区细胞外5-羟色胺水平和DRN神经元活性。 将生成CRF效应的剂量-反应曲线(给药 I.C.V.或中缝内)对外侧隔、杏仁核和脑内5-HT释放的影响 皮质和DRN神经元活动。促肾上腺皮质激素释放激素拮抗剂的疗效 (静脉注射、全身注射或静脉注射)以防止这些 效果将会确定。这个AIM将揭示CRF是否起作用 直接在DRN内改变前脑5-羟色胺的释放，是否有作用 5-羟色胺的释放是地区性的，CRF受体亚型 参与其中；2)确定在此期间内源性 CRF对DRN-5-HT系统的影响促肾上腺皮质激素释放激素拮抗剂的能力 (静脉注射)或脑内注射)以防止前脑5-羟色胺的变化 由不同挑战引发的释放将被确定。此目标 将揭示CRF-5-HT相互作用的条件； 3)鉴定DRN中CRF-5-HT相互作用的细胞底物 并识别CRF对DRN的传入。CRF之间的相互作用 DRN中的终端和5-HT过程将在 超微结构双标记免疫组织化学和电子显微镜观察 显微镜。将使用神经束追踪来识别CRF DRN的传入神经。这一目标将揭示潜在的细胞机制 基础CRF-5-HT相互作用，并提供CRF如何 系统链接到DRN；4)阐明CRF-5-HT相互作用的作用 一种与抑郁有关的行为。慢性肾衰的假设 DRN释放及随后对5-羟色胺前脑释放的抑制 与游泳应激相关的潜在行为不动将是 测试过。CRF或CRF拮抗剂(静脉注射)的作用。或 在强迫游泳测试中的行为将被确定。这 AIM将揭示CRF-5HT潜在的病理生理后果 互动。

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.