Strassman A M, Potrebic S, Maciewicz R J
Department of Neurology, Massachusetts General Hospital, Charlestown.
J Comp Neurol. 1994 Aug 15;346(3):349-65. doi: 10.1002/cne.903460304.
Single unit recording studies in anesthetized cats have identified a population of neurons in the brainstem trigeminal complex that can be activated by stimulation of major dural blood vessels. Such dura-responsive neurons exhibit response properties that are appropriate for a role in the mediation of vascular head pain in that they typically exhibit nociceptive facial receptive fields whose periorbital distribution is similar to the region of referred pain evoked by dural stimulation in humans. In the present study, intracellular labelling with horseradish peroxidase was used to examine the anatomical characteristics of brainstem trigeminal neurons that respond to dural stimulation. A total of 17 neurons was labelled that responded to electrical stimulation of dural sites overlying the superior sagittal sinus or middle meningeal artery. Fourteen of these neurons also responded to electrical stimulation of the cornea. The neurons in this sample were located in the rostral two-thirds of the trigeminal nucleus caudalis and the caudalmost part of the nucleus interpolaris. Within caudalis, the neurons were located in the deeper part of the nucleus, primarily lamina V, and were concentrated ventrolaterally. The dendritic arborizations of the dura-responsive neurons typically exhibited a dorsolateral-to-ventromedial orientation and did not extend into the superficial laminae of caudalis. Dura-responsive neurons had axonal collaterals and boutons in the nucleus caudalis, nucleus interpolaris, the infratrigeminal region ventral to nucleus interpolaris, the nucleus of the solitary tract, and the medullary reticular formation. The axonal boutons within the trigeminal complex exhibited a ventrolateral distribution which largely overlapped the distribution of the somata. The results are consistent with previous evidence that dura-responsive brainstem trigeminal neurons may have a role in the mediation of dural vascular head pain and also indicate that such neurons may contribute to nociceptive processing within the dorsal horn.
对麻醉猫进行的单单位记录研究已确定，脑干三叉神经复合体中有一群神经元可被主要硬脑膜血管的刺激激活。这类对硬脑膜有反应的神经元表现出的反应特性，适合在血管性头痛的介导中发挥作用，因为它们通常表现出伤害性面部感受野，其眶周分布类似于人类硬脑膜刺激诱发的牵涉痛区域。在本研究中，使用辣根过氧化物酶进行细胞内标记，以检查对硬脑膜刺激有反应的脑干三叉神经神经元的解剖学特征。总共标记了17个对覆盖上矢状窦或脑膜中动脉的硬脑膜部位进行电刺激有反应的神经元。其中14个神经元对角膜的电刺激也有反应。该样本中的神经元位于三叉神经尾侧核头端的三分之二和极间核的最尾端部分。在尾侧核内，神经元位于核的较深部位，主要在第V层，并集中在腹外侧。对硬脑膜有反应的神经元的树突分支通常呈背外侧向腹内侧方向，且不延伸至尾侧核的浅层。对硬脑膜有反应的神经元在三叉神经尾侧核、极间核、极间核腹侧的三叉下区域、孤束核和延髓网状结构中有轴突侧支和终扣。三叉神经复合体内的轴突终扣呈腹外侧分布，在很大程度上与胞体的分布重叠。这些结果与之前的证据一致，即对硬脑膜有反应的脑干三叉神经神经元可能在硬脑膜血管性头痛的介导中起作用，也表明这类神经元可能参与背角内的伤害性信息处理。
