ENDOCYTOSIS OF MESOLIMBIC OPIOID AND DOPAMINE RECEPTORS

在这些研究中，观察到吗啡对内细胞膜有意想不到的影响。 Mu阿片受体(MOR)在大鼠生理相关中棘神经元中的转运 伏隔核和原代培养中，以及对内体募集的意外调节作用 在这些神经元的树突中也观察到了非视觉(β)阻滞物。拟议的研究旨在 阐明中等刺神经元MOR调节效应的机制基础，并检测其特异性 关于阿片和共表达的多巴胺受体可能调节功能的假说相关 对中脑边缘多巴胺功能和阿片类药物的奖赏作用。《公约》的具体目标 建议进行的研究包括： (1)明确吗啡诱导的MOR内吞作用和内体募集β-拦阻素的机制 在中等刺状神经元中。拟议的研究试图阐明这些问题的机制基础。 前所未有的吗啡效应。需要检验的假设是莫尔的内吞作用和内吞作用 在MOR中，β-arrestin的募集是胞浆特异性磷酸化(S)的结果。 (2)明确多巴胺D_1受体在相关MOR表达神经元中的调节机制。MOR-表达 中等脊髓神经元是VTA多巴胺能信号转导的主要靶点 受体(D1R)。初步研究表明，药物介导的MOR，本质上是通过 将β-受体阻滞剂“隔离”在内体上，可能会减弱Arestin依赖的D1R内吞作用 多巴胺。这一假说将通过定点突变和已建立的共转染进行验证。 方法在大鼠纹状体神经元上进行培养。 (3)利用活细胞成像方法显示药物对相关受体和arrestin转运的影响 实时事件。GFP标记和活细胞显像法研究MOR在大鼠体内的调控转运 纹状体神经元，专注于药物介导的激活后MOR循环的空间方面。

During these studies morphine was observed to have unexpected effects on the endocytic membrane trafficking of the mu opioid receptor (MOR) in physiologically relevant medium spiny neurons in the rat Nucleus Accumbens and in primary culture, and unexpected regulatory effects on endosome recruitment of non-visual (beta-) arrestins were also observed in dendrites of these neurons. The proposed studies seek to elucidate the mechanistic basis of MOR regulatory effects in medium spiny neurons, and to test specific hypotheses regarding possible regulatory functions on opioid and co-expressed dopamine receptors relevant to mesolimbic dopamine function and the rewarding effects of opioid drugs. The Specific Aims of the proposed studies are to: (1) Define mechanisms of morphine-induced endocytosis of MOR and endosome recruitment of beta-arrestins in medium spiny neurons. The proposed studies seek to elucidate the mechanistic basis of these unprecedented morphine effects. The hypothesis to be tested is that MOR endocytosis and endosome recruitment of beta-arrestin is a consequence of specific cytoplasmic phosphorylation(s) in MOR. (2) Identify mechanisms of D1 dopamine receptor regulation in relevant MOR-expressing neurons. MOR-expressing medium spinal neurons are major targets of VTA dopaminergic signaling via co-expressed D1 receptors (D1R). Preliminary studies suggest that drug-mediated activation of MOR, by essentially 'sequestering' beta-arrestins on endosomes, may attenuate arrestin-dependent D1R endocytosis induced by dopamine. This hypothesis will be tested using site-directed mutagenesis and established co-transfection methods in rat striatal neurons. (3) Utilize live cell imaging methods to visualize drug effects on relevant receptor and arrestin trafficking events in real time. GFP tagging and live cell imaging methods to the regulated trafficking of MOR in rat striatal neurons, focusing on spatial aspects of MOR recycling following drug-mediated activation.