International Journal of Oral Science ( IF 14.9 ) Pub Date : 2020-09-29 , DOI: 10.1038/s41368-020-00095-0 Jun Li 1 , Kaige Ma 1 , Dan Yi 2 , Chun-do Oh 1 , Di Chen 1, 2
Orofacial pain or tenderness is a primary symptom associated with temporomandibular joint (TMJ) disorders (TMDs). To understand the pathological mechanisms underlying TMDs, several mouse models have been developed, including mechanical stimulus-induced TMD and genetic mouse models. However, a lack of feasible approaches for assessing TMD-related nociceptive behaviours in the orofacial region of mice has hindered the in-depth study of TMD-associated mechanisms. This study aimed to explore modifications of three existing methods to analyse nociceptive behaviours using two TMD mouse models: (1) mechanical allodynia was tested using von Frey filaments in the mouse TMJ region by placing mice in specially designed chambers; (2) bite force was measured using the Economical Load and Force (ELF) system; and (3) spontaneous feeding behaviour tests, including eating duration and frequency, were analysed using the Laboratory Animal Behaviour Observation Registration and Analysis System (LABORAS). We successfully assessed changes in nociceptive behaviours in two TMD mouse models, a unilateral anterior crossbite (UAC)-induced TMD mouse model and a β-catenin conditional activation mouse model. We found that the UAC model and β-catenin conditional activation mouse model were significantly associated with signs of increased mechanical allodynia, lower bite force, and decreased spontaneous feeding behaviour, indicating manifestations of TMD. These behavioural changes were consistent with the cartilage degradation phenotype observed in these mouse models. Our studies have shown reliable methods to analyse nociceptive behaviours in mice and may indicate that these methods are valid to assess signs of TMD in mice.
中文翻译:
颞下颌关节疾病小鼠模型的伤害性行为评估
口面部疼痛或压痛是与颞下颌关节 (TMJ) 疾病 (TMD) 相关的主要症状。为了了解 TMD 的病理机制,已经开发了几种小鼠模型,包括机械刺激诱导的 TMD 和遗传小鼠模型。然而,缺乏评估小鼠口面部 TMD 相关伤害性行为的可行方法阻碍了对 TMD 相关机制的深入研究。本研究旨在探索对使用两种 TMD 小鼠模型分析伤害性行为的三种现有方法的改进:(1)通过将小鼠置于专门设计的腔室中,在小鼠 TMJ 区域使用 von Frey 细丝测试机械性异常性疼痛;(2) 使用经济负载和力 (ELF) 系统测量咬合力;(3) 自主进食行为测试,包括进食持续时间和频率,使用实验动物行为观察注册和分析系统(LABORAS)进行分析。我们成功地评估了两种 TMD 小鼠模型中伤害性行为的变化,一种单侧前牙反咬合 (UAC) 诱导的 TMD 小鼠模型和一种 β-catenin 条件激活小鼠模型。我们发现 UAC 模型和 β-catenin 条件激活小鼠模型与机械异常性疼痛增加、咬合力降低和自发进食行为减少的迹象显着相关,表明 TMD 的表现。这些行为变化与在这些小鼠模型中观察到的软骨降解表型一致。