Mørch C D, Hu J W, Arendt-Nielsen L, Sessle B J
Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark.
Eur J Neurosci. 2007 Jul;26(1):142-54. doi: 10.1111/j.1460-9568.2007.05608.x.
The convergence of cutaneous, musculoskeletal, dural and visceral afferents onto nociceptive neurons in the first cervical dorsal horn was investigated in urethane/chloralose-anesthetized rats. Electrical stimulation was applied to facial, neck, shoulder and forepaw skin, cornea (COR), dura, second cervical (C2) nerve, hypoglossal nerve, temporomandibular joint, masseter (MAS) muscle and superior laryngeal nerve. In addition, acetic acid was injected intraperitoneally and microinjection of glutamate was applied to the tongue, MAS muscle, splenius cervicis muscle, dura and intrapericardial area. A total of 52 nociceptive neurons classified as wide dynamic range (n = 28) or nociceptive-specific (n = 24) was studied. All nociceptive neurons received afferent input from the skin and at least one COR, musculoskeletal, dural or visceral afferent source in the trigeminal (V) or cervical area but input from afferent sources caudal to the C2 innervation territory was sparse. The proportion of neurons responding to COR, dural, C2 nerve, hypoglossal nerve, temporomandibular joint, MAS muscle and superior laryngeal nerve stimulations was 87, 54, 85, 52, 73, 64 and 31%, respectively. Electrical stimulation of all tested sites showed a double logarithmic stimulus-response relation, and cluster analysis of the excitability to COR, musculoskeletal, dural and visceral stimulations revealed two groups of neurons, one mainly containing wide dynamic range neurons and one mainly containing nociceptive-specific neurons. These findings indicate that afferent convergence in first cervical dorsal horn nociceptive neurons may be limited to the craniofacial area and that they may play an important role in the integration of craniofacial and upper cervical nociceptive inputs.
在氨基甲酸乙酯/水合氯醛麻醉的大鼠中，研究了皮肤、肌肉骨骼、硬脑膜和内脏传入神经在第一颈背角伤害性神经元上的汇聚情况。对大鼠的面部、颈部、肩部和前爪皮肤、角膜（COR）、硬脑膜、第二颈神经（C2）、舌下神经、颞下颌关节、咬肌（MAS）和喉上神经施加电刺激。此外，腹腔注射醋酸，并将谷氨酸微量注射到舌头、MAS肌肉、颈夹肌、硬脑膜和心包内区域。共研究了52个分类为广动力范围（n = 28）或伤害性特异性（n = 24）的伤害性神经元。所有伤害性神经元均接受来自皮肤以及三叉神经（V）或颈部区域中至少一种COR、肌肉骨骼、硬脑膜或内脏传入源的传入输入，但来自C2神经支配区域尾侧传入源 的输入较少。对COR、硬脑膜、C2神经、舌下神经、颞下颌关节、MAS肌肉和喉上神经刺激产生反应的神经元比例分别为87%、54%、85%、52%、73%、64%和31%。对所有测试部位的电刺激均显示出双对数刺激-反应关系，对COR、肌肉骨骼、硬脑膜和内脏刺激的兴奋性聚类分析揭示了两组神经元，一组主要包含广动力范围神经元，另一组主要包含伤害性特异性神经元。这些发现表明，第一颈背角伤害性神经元的传入汇聚可能仅限于颅面部区域，并且它们可能在颅面部和上颈部伤害性输入的整合中起重要作用。
