Identifying new targets in pain, utilizing the novel analgesic AS1

项目摘要 疼痛是患者寻求医疗保健的头号原因，超过20%的美国人口受到影响 慢性疼痛所致。现有的治疗方法疗效有限，治疗期很短，同时也唤起了 有害的副作用。因此，了解疼痛的过程对于开发新的 治疗公司来解决这一紧迫的医疗危机。根据国际研究协会的说法 疼痛(IASP)是一种与实际或潜在的痛苦相关的不愉快的感觉和情感体验 组织损伤“。由疼痛感知引起的情感痛苦的内在归因是一种消极的 对伤害性刺激的效价。厌恶动机回路的失调可能是许多 与慢性疼痛状况相关的痛苦。享乐价是对内在价值的衡量 刺激的吸引力(积极)或反感(消极)。疼痛通常是负价的，这是 通常是有利的，驱使自我保护行为。反常的是，人类有时可以赋予一个积极的 对伤害性刺激的重视；从辛辣的食物中获得快感。这意味着神经回路分配给 伤害性刺激的负价是可塑性的，疼痛和厌恶可以分离。关键是， 用来研究神经细胞如何将价分配给伤害性刺激的工具有限。 系统。在这里，我们建议研究痛觉屏蔽1(AS1)对伤害性加工的影响。 我们发现的小分子逆转了享乐主义的动机(移动到或离开) 伤害性刺激，包括热和斑马鱼幼体中的有毒化学物质异硫氰酸烯丙酯(AITC)， 以剂量依赖的方式使这些高度厌恶的刺激具有吸引力或回报。值得注意的是，AS1 可以调节伤害性刺激的价态，将价态从厌恶转变为中性，再转变为吸引人。AS1 没有先前确定的目标或功能。我们假设AS1增强了肌动蛋白的活性。 多巴胺奖赏系统通过激活D1受体促进多巴胺的释放 伤害性刺激。该方案中的实验将利用斑马鱼和 小鼠模型系统来检验这些假说，当完成后，我们将表征 AS1在伤害性感受上的作用，并确定AS1作用于哪个神经回路来逆转伤害性感受的价态 从厌恶到吸引人的刺激。在目标1中，我们建议确定AS1对由 伤害性刺激和其他厌恶刺激以及这些刺激如何改变中枢神经系统中的神经元活动 或者斑马鱼中没有AS1。在目标2中，我们将使用全面的遗传学方法来评估 依赖D1R的多巴胺能信号转导伤害性刺激引起的厌恶 斑马鱼中不存在AS1。在目标3中，我们将确定AS1对伤害感、位置厌恶、 这些效应是否依赖于D1受体的激活以及AS1对神经元活动的影响。 采用小鼠中枢神经系统对伤害性刺激的反应。

Project Summary Pain is the number one reason patients seek health care and greater than 20% of the US population is affected by chronic pain. Existing therapeutics have limited efficacy and a narrow therapeutic period, while also evoking deleterious side effects. It is therefore vital to understand pain processing in order to develop novel therapeutics to address this pressing health care crisis. According to the International Association for the Study of Pain (IASP) pain is “an unpleasant sensory and emotional experience associated with actual or potential tissue damage”. Intrinsic to the emotional suffering elicited by pain perception is the attribution of a negative valence to nociceptive stimuli. Dysregulation of aversive motivational circuits may underlie much of the suffering associated with chronic pain conditions. Hedonic valence is a measurement of the intrinsic attractiveness (positive) or averseness (negative) of a stimulus. Pain typically has a negative valence, which is normally advantageous, driving self-protective behavior. Perversely, humans can sometimes assign a positive valence to nociceptive stimuli; think pleasure from spicy foods. This implies that the neural circuits that assign negative valence to nociceptive stimuli are malleable and that pain and aversion can be decoupled. Critically, there have been limited tools to investigate how valence is assigned to nociceptive stimuli by the nervous system. Here, we propose to investigate the effects on nociceptive processing by Analgesic Screen 1 (AS1), a small molecule we discovered that reverses the hedonic motivation (movement toward or away from) of nociceptive stimuli including heat and the noxious chemical allyl isothiocyanate (AITC) in larval zebrafish, rendering these highly aversive stimuli attractive or rewarding in a dose dependent manner. Remarkably, AS1 can tune the valence of nociceptive stimuli, transforming the valence from aversive to neutral to attractive. AS1 has no previously identified target or function. We hypothesize that AS1 potentiates the activity of the dopamine reward system via D1 receptor activation by promoting release of dopamine in the presence of nociceptive stimuli. Experiments in this proposal will make use of the unique advantages of the zebrafish and mouse model systems to test these hypotheses and when completed, we will have characterized the effects of AS1 on nociception and identified upon which neural circuits AS1 acts to invert the valence of nociceptive stimuli from aversive to attractive. In Aim 1, we propose to determine the effects of AS1 on aversion evoked by nociceptive and other aversive stimuli and how these stimuli alter neuronal activity in the CNS in the presence or absence of AS1 in zebrafish. In Aim 2, we will use a comprehensive genetic approach to assess the role of D1 receptor dependent dopaminergic signaling on aversion elicited by nociceptive stimuli in the presence or absence of AS1 in zebrafish. In Aim 3, we will ascertain the effect of AS1 on nociception, place aversion, whether these effects are dependent on D1 receptor activation and where AS1 effects neuronal activity in the CNS in response to nociceptive stimuli using the mouse model system.