A Novel Gnawing Assay to Quantify Nociception in Models of Chronic Orofacial Pain

描述（由申请人提供）：慢性口面疼痛影响10%的美国人，目前没有有效的治疗方法。最常见和最严重的口面疼痛形式包括头颈癌疼痛、颞下颌关节疼痛和咀嚼肌疼痛。口面部疼痛患者的主要功能问题是咀嚼疼痛。然而，没有动物行为测定来量化伤害感受对口腔功能的影响，并且与患者的症状相对应。我们假设慢性口面疼痛产生可量化的咀嚼变化。此外，我们假设，减少啃功能可以作为一种措施的伤害感受。为了验证这些假设，我们设计了一种新的装置，该装置可以客观地测量啮齿动物的啃咬功能。在这个项目中，我们将使用我们的新设备来量化头颈癌疼痛，颞下颌关节疼痛和咀嚼肌疼痛动物模型中咀嚼功能的显著损害。为了证实这三种模型中改变的啃咬功能是继发于疼痛的，我们将证明临床上用于治疗这些形式的慢性疼痛的药物的逆转。我们预计，我们的工作将从根本上提高三叉神经系统的伤害性机制的理解，提供一个定量的功能伤害性测定，不依赖于主观的行为解释，不需要观察时间的调查。

DESCRIPTION (provided by applicant): Chronic orofacial pain affects 10% of Americans and there currently is no effective treatment. The most common and most severe forms of orofacial pain include head and neck cancer pain, TMJ pain and masticatory muscle pain. The primary functional problem for orofacial pain patients is pain with chewing. However, there is no animal behavioral assay that quantifies the impact of nociception on oral function and that parallels the symptoms of patients. We hypothesize that chronic orofacial pain produces quantifiable masticatory changes. Moreover, we hypothesize that reduced gnawing function can be used as a measure of nociception. To test these hypotheses we have designed, custom built and pilot tested a novel device that objectively measures gnawing function in rodents. In this project we will use our novel device to quantify significant impairment of gnawing function in animal models of head and neck cancer pain, TMJ pain and masticatory muscle pain. To confirm that the altered gnawing function in the three models is secondary to pain we will demonstrate reversal with agents used clinically to treat these forms of chronic pain. We anticipate that our work will contribute fundamentally to improved understanding of nociceptive mechanisms of the trigeminal system by providing a quantitative functional nociceptive assay that does not depend on subjective behavioral interpretation and does not require observational time by an investigator.