Iwata K, Tsuboi Y, Tashiro A, Sakamoto M, Hagiwara S, Kohno M, Sumino R
Department of Oral Physiology, Osaka University Faculty of Dentistry, Japan.
J Oral Sci. 1998 Dec;40(4):159-63. doi: 10.2334/josnusd.40.159.
The mesencephalic projection pattern of axons arising from the medullary dorsal horn (MDH) was studied on the basis of axonal transport of Phaseolus vulgaris Leucoagglutinin (PHA-L). After large injections of PHA-L into both the superficial and deep laminae of the MDH, labeled fibers were observed in the anterior pretectal area (ATP), internal gray matter of the superior colliculus (InG), and rostral linear raphe nucleus (RLi) in the contralateral mesencephalon, and also in the ipsilateral parabrachial nucleus (PBA). Restriction of PHA-L to only the superficial laminae resulted in heavy axon labeling and varicosity in the APT and little labeling in the lateral part of the InG of the contralateral mesencephalic nuclei and the dorsal part of the ipsilateral PBA. On the other hand, after injections into the deep laminae, labeled axons were distributed mainly in the contralateral InG and RLi. Therefore, it is concluded that there are two different major pain pathways from the superficial and deep laminae of the MDH to the mesencephalic nuclei, processing nociceptive information in the trigeminal system.
基于菜豆白细胞凝集素（PHA-L）的轴突运输，研究了源自延髓背角（MDH）的轴突的中脑投射模式。在将大量PHA-L注入MDH的浅层和深层后，在对侧中脑的前顶盖前区（ATP）、上丘内部灰质（InG）和吻侧线形中缝核（RLi）以及同侧臂旁核（PBA）中观察到标记纤维。将PHA-L仅限制在浅层会导致ATP中轴突大量标记和出现静脉曲张，而对侧中脑核团InG的外侧部分和同侧PBA的背侧部分标记较少。另一方面，注入深层后，标记轴突主要分布在对侧InG和RLi中。因此，可以得出结论，从MDH的浅层和深层到中脑核团存在两条不同的主要疼痛通路，它们在三叉神经系统中处理伤害性信息。
