MIXED NOP/MU COMPOUNDS AND THE INVOLVEMENT OF THEIR RECEPTORS IN ANALGESIA

NOP受体是阿片受体家族的第四个成员，一直是研究的目标 自1993年发现以来，在药理学、解剖学和激动剂引起的行为方面， 对抗者。尽管做出了相当大的研究努力，但缺乏合适的受体抗体阻碍了 对许多与受体定位、内化和受体的细节有关的研究进行适当的解释 二聚化。为了测试与NOP受体功能有关的假说，Brigitte Kieffer博士和 同事们已经培育出携带与NOP偶联的绿色荧光蛋白(EGFP)的敲入小鼠 受体。类似的GFP标记的Delta受体和mCherry标记的Mu受体敲入小鼠已经被证明是非常 有助于了解Delta和Mu的解剖、细胞定位和功能之间的关系 阿片受体。与u受体一样，nop受体在所有与疼痛相关的 大脑区域，包括PAG，RVM，MHb，丘脑等。然而，NOP受体不同于其他 NOP受体激动剂中阿片受体家族的成员在给药时阻断阿片类镇痛 I.C.V.同时在鞘内给药时具有抗伤害反应活性。此外，NOP受体激动剂 在慢性疼痛状态下似乎更有效，而不是更差。这很令人惊讶，因为NOP 背根神经节和扣带回前部受体mRNA减少，NOP受体部分减少 脊神经结扎小鼠的脊髓板层。利用NOP-EGFP(+/+)小鼠，进行免疫组织化学实验 将更好地了解脑、脊髓和背根节中的电路和细胞定位 这导致了N/OFQ和其他NOP受体激动剂的这些不寻常的特性。这些将是相关的 通过在特定脑区微量注射后的行为实验来了解NOP如何 受体的激活调节疼痛的感觉和情感成分。具体目标1将 仔细检查NOP-EGFP受体在DRG中的位置以及确定疼痛的方式(热， 冷，触摸)通过全身给予NOP激动剂和拮抗剂而减弱，并确定这些 慢性神经病理性和炎症性疼痛期间的参数变化。特定目标2将检查脊髓 NOP-EGFP的表达以及脊髓向大脑和外周的投射的特征。 这些结果将与鞘内注射NOP激动剂对不同疼痛方式的效果进行比较。 给药假手术和神经病小鼠。《特定目标3》将检查神经病理性疼痛引起的变化 在脑中NOP-EGFP受体的水平，特别是在涉及感觉(PAG)和 疼痛的情感(ACC)成分。将NOP受体激动剂和拮抗剂直接注射到 大脑区域将被用来更好地理解NOP受体相关的电路，该电路调节温度， 触觉，和情绪上的痛苦通过这些大脑区域。这些实验将清楚地确定NOP的作用 在急性和慢性热痛和触觉痛、痛觉过敏和痛觉过敏中的受体。

The NOP receptor, the fourth member of the opioid receptor family, has been the target of investigation since its discovery in 1993, with respect to pharmacology, anatomy, and behaviors elicited by agonists and antagonists. Despite considerable research efforts, the lack of suitable receptor antibodies has prevented the appropriate interpretation of many studies pertaining to the details of receptor location, internalization, and dimerization. In order to test hypotheses pertaining to NOP receptor function, Dr. Brigitte Kieffer and colleagues have generated knock-in mice that carry green fluorescent protein (eGFP) coupled to the NOP receptor. Similar GFP-tagged delta receptor and mCherry-tagged mu receptor knock-in mice have proven very useful in understanding the relationship among anatomy, cellular localization, and function of delta and mu opioid receptors. Like the mu receptor, NOP receptors are found in very high numbers in all of the pain-related brain regions, including PAG, RVM, MHb, thalamus, etc. However, NOP receptors are unlike the other members of the opiate receptor family in that NOP receptor agonists block opiate analgesia when administered i.c.v. while having antinociceptive activity when administered intrathecally. In addition, NOP receptor agonists appear to be more effective rather than less effective in chronic pain states. This is surprising since NOP receptor mRNA decreases in DRG and anterior cingulate cortex (ACC) and NOP receptors decrease in certain spinal cord laminae in spinal nerve ligated mice. Using NOP-eGFP(+/+) mice, immunohistochemical experiments will be carried out to better understand the circuitry and the cellular localization in brain, spinal cord, and DRG that leads to these unusual properties of N/OFQ and other NOP receptor agonists. These will be correlated with behavioral experiments subsequent to microinjections into specific brain regions to understand how NOP receptor activation modulates the sensory as well as the affective component of pain. Specific Aim 1 will carefully examine the location of NOP-eGFP receptors in DRG as well as determine the pain modalities (heat, cold, touch) attenuated by systemic administration of NOP agonists and antagonists and determine how these parameters change during chronic neuropathic and inflammatory pain. Specific Aim 2 will examine spinal cord NOP-eGFP expression as well as characterize spinal projections both to the brain and to the periphery. These results will be compared with the effects of NOP agonists on different pain modalities after intrathecal administration in sham and neuropathic mice. Specific Aim 3 will examine neuropathic pain-induced changes in NOP-eGFP receptor levels in brain with particular emphasis on regions involved in the sensory (PAG) and affective (ACC) components of pain. Direct injections of NOP receptor agonists and antagonists into these brain regions will be used to better understand the NOP receptor-related circuitry that modulates thermal, tactile, and emotional pain through these brain regions. These experiments will clearly identify the role of NOP receptors in acute and chronic thermal and tactile pain, allodynia and hyperalgesia.