Neurobiology and molecular mechanisms of the opioid system

阿片系统是研究最多的神经肽系统之一，因为它在调节疼痛和奖赏/成瘾等基本生理功能方面具有重要意义。除了疼痛通路和奖赏中心外，阿片受体和多肽也存在于中枢神经系统的不同区域，其作用和功能尚未被描述和/或仍然知之甚少。例如，阿片系统在嗅球/嗅束中的作用尚未解决。此外，阿片受体在特定神经元群体以及小胶质细胞中的存在似乎存在争议。最后，阿片配体及其受体的作用所涉及的信号级联仍有待全面描述。拟议研究方案的总体目标是促进我们对阿片系统的了解，特别强调未探索的脑区和细胞群以及阿片受体激活所涉及的信号级联。短期目标概要：短期目标1：研究MOP和DOP在主要嗅球中的作用利用我实验室的独特工具和商业上可用的小鼠模型，我们将研究MOP和DOP在嗅球/束内的定位和投射。我们还将使用药理学和行为学的方法研究它们在这一结构中的作用。短期目标2：研究小胶质细胞中的DOP利用我们的基因工程小鼠以及商业上可用的模型，我们将产生DOP将在小胶质细胞中选择性表达的小鼠系(条件性敲打蛋白)。然后，药理学和行为学测试将被用来确定阿片系统在这些细胞中的角色和功能。短期目标3：发现和表征MOP和DOP参与的新的信号级联。我们将使用邻近标记方法(APEX2融合到MOP和DOP的C-末端尾巴)来识别和研究这些受体的新的信号伙伴，以解开它们的“信号体”。结合质谱学，这一分析将用于为这些受体寻找新的信号伙伴。拟议的研究将提供对阿片系统和不同信号级联的更深入了解，这两个方面对于充分理解阿片系统的一系列功能至关重要。拟议的研究方案还为在舍布鲁克药理研究所提供的巨大环境中对HQP进行阿片类药物系统培训提供了机会。

The opioid system is one of the most studied neuropeptide systems because of its significant implication in regulating essential physiological functions such as pain and reward/addiction. Aside pain pathways and reward centers, opioid receptors and peptides are also present in various regions of the central nervous system where their roles and functions have not yet been described and/or remain poorly understood. For instance, the role of the opioid system in the olfactory bulb/tract has not been solved. Additionally, the presence of the opioid receptors in specific neuronal populations as well as in microglia appears controversial. Finally, the signaling cascades involved in the action of the opioid ligands and their receptors remain to be fully described. The overarching goal of the proposed research program is to further our knowledge of the opioid system, with a particular emphasis on unexplored brain regions and populations of cells as well as on the signaling cascades engaged by the activation of the opioid receptors. Brief outline of the short-term goals:Short-term goal 1: Investigate the role of MOP and DOP in the main olfactory bulbUsing unique tools in my lab together with commercially available mouse models, we will study the localization and identify the projections of MOP and DOP expressing cells within the olfactory bulb/tract. We will also investigate their roles in this structure using pharmacological and behavioral approaches.Short-term goal 2: Study DOP in microgliaUsing our genetically-engineered mice as well as commercially available models, we will generate mouse lines in which DOP will be selectively expressed (conditional knockins) in microglia. Pharmacological and behavioral tests will then be employed to determine roles and functions of the opioid system in these cells.Short-term goal 3: Discover and characterize novel signaling cascades engaged by MOP and DOPWe will identify and study novel signaling partners for these receptors using a proximity-labeling approach (APEX2 fused to the C-terminal tail of MOP and DOP) to unravel their “signalosome”. Combined to mass spectrometry, this assay will be used to identify novel signaling partners for these receptors.The proposed research will provide a greater depth of understanding of the opioid system and the different signaling cascades, two aspects essential for fully understanding the array of functions of the opioid system. The proposed research program also provides an opportunity for training HQP on the opioid system in the tremendous environment offered at the Sherbrooke's Institute of Pharmacology.