Patients with temporomandibular disorders (TMDs) typically experience facial pain and discomfort or tenderness in the temporomandibular joint (TMJ), causing disability in daily life. Unfortunately, existing treatments for TMD are not always effective, creating a need for more advanced, mechanism-based therapies. In this study, we used in vivo GCaMP3 Ca2+ imaging of intact trigeminal ganglia (TG) to characterize functional activity of the TG neurons in vivo, specifically in mouse models of TMJ injury and inflammation. This system allows us to observe neuronal activity in intact anatomical, physiological, and clinical conditions and to assess neuronal function and response to various stimuli. We observed a significant increase in spontaneously and transiently activated neurons responding to mechanical, thermal, and chemical stimuli in the TG of mice with TMJ injection of complete Freund adjuvant or with forced mouth opening (FMO). An inhibitor of the calcitonin gene-related peptide receptor significantly attenuated FMO-induced facial hypersensitivity. In addition, we confirmed the attenuating effect of calcitonin gene-related peptide antagonist on FMO-induced sensitization by in vivo GCaMP3 Ca2+ imaging of intact TG. Our results contribute to unraveling the role and activity of TG neurons in the TMJ pain, bringing us closer to understanding the pathophysiological processes underlying TMJ pain after TMJ injury. Our study also illustrates the utility of in vivo GCaMP3 Ca2+ imaging of intact TG for studies aimed at developing more targeted and effective treatments for TMJ pain.

中文翻译：

---

通过完整三叉神经节神经元的体内 GCaMP Ca2 + 成像阐明颞下颌关节损伤和炎症小鼠模型中的神经元活性。


颞下颌关节疾病 （TMD） 患者通常会在颞下颌关节 （TMJ） 出现面部疼痛和不适或压痛，从而导致日常生活残疾。不幸的是，现有的 TMD 治疗方法并不总是有效的，因此需要更先进的、基于机制的疗法。在这项研究中，我们使用完整三叉神经节 （TG） 的体内 GCaMP3 Ca2 + 成像来表征体内 TG 神经元的功能活性，特别是在 TMJ 损伤和炎症的小鼠模型中。该系统使我们能够在完整的解剖学、生理学和临床条件下观察神经元活动，并评估神经元功能和对各种刺激的反应。我们观察到 TMJ 注射完全弗氏佐剂或强制张口 （FMO） 的小鼠 TG 中自发和瞬时激活的神经元对机械、热和化学刺激的反应显着增加。降钙素基因相关肽受体的抑制剂显着减轻了 FMO 诱导的面部超敏反应。此外，我们通过完整 TG 的体内 GCaMP3 Ca2 + 成像证实了降钙素基因相关肽拮抗剂对 FMO 诱导的致敏作用。我们的结果有助于揭示 TG 神经元在 TMJ 疼痛中的作用和活性，使我们更接近于 TMJ 损伤后 TMJ 疼痛的病理生理过程。我们的研究还说明了完整 TG 的体内 GCaMP3 Ca2 + 成像在旨在开发更针对性和更有效的 TMJ 疼痛治疗方法的研究中的效用。