Presto Peyton, Ji Guangchen, Junell Riley, Griffin Zach, Neugebauer Volker
Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, 3601 4th St, Lubbock, TX 79430-6592, USA.
Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX 79430-6592, USA.
Brain Sci. 2021 Oct 11;11(10):1339. doi: 10.3390/brainsci11101339.
Inter-individual and sex differences in pain responses are recognized but their mechanisms are not well understood. This study was intended to provide the behavioral framework for analyses of pain mechanisms using fear extinction learning as a predictor of phenotypic and sex differences in sensory (mechanical withdrawal thresholds) and emotional-affective aspects (open field tests for anxiety-like behaviors and audible and ultrasonic components of vocalizations) of acute and chronic pain. In acute arthritis and chronic neuropathic pain models, greater increases in vocalizations were found in females than males and in females with poor fear extinction abilities than females with strong fear extinction, particularly in the neuropathic pain model. Female rats showed higher anxiety-like behavior than males under baseline conditions but no inter-individual or sex differences were seen in the pain models. No inter-individual and sex differences in mechanosensitivity were observed. The data suggest that vocalizations are uniquely suited to detect inter-individual and sex differences in pain models, particularly in chronic neuropathic pain, whereas no such differences were found for mechanosensitivity, and baseline differences in anxiety-like behaviors disappeared in the pain models.
疼痛反应中的个体差异和性别差异已得到认可，但其机制尚未完全明确。本研究旨在提供行为框架，以便利用恐惧消退学习作为急性和慢性疼痛的感觉（机械性退缩阈值）和情绪情感方面（焦虑样行为的旷场试验以及发声的可听和超声成分）表型及性别差异的预测指标，来分析疼痛机制。在急性关节炎和慢性神经病理性疼痛模型中，发现雌性比雄性发声增加更多，且恐惧消退能力差的雌性比恐惧消退能力强的雌性发声增加更多，尤其是在神经病理性疼痛模型中。在基线条件下，雌性大鼠比雄性大鼠表现出更高的焦虑样行为，但在疼痛模型中未观察到个体间或性别差异。未观察到机械敏感性的个体间和性别差异。数据表明，发声特别适合于检测疼痛模型中的个体间和性别差异，尤其是在慢性神经病理性疼痛中，而机械敏感性未发现此类差异，且疼痛模型中焦虑样行为的基线差异消失。
