Basbaum A I, Fields H L
J Comp Neurol. 1979 Oct 1;187(3):513-31. doi: 10.1002/cne.901870304.
There is considerable evidence that the dorsolateral funiculus (DLF) of the spinal cord contains descending pathways critical for both opiate and brainstem stimulation-produced analgesia. To obtain a comprehensive map of brainstem neurons projecting to the spinal cord via the DLF, large injections of horseradish peroxidase (HRP) were made into the lumbosacral spinal cord of cat and rat. These injections were made caudal to midthoracic lesions which spared only a single DLF or ventral quadrant (VQ); thus only those neurons whose axons descended in the spared funiculus would be labelled. Cells with descending axons in the VQ were concentrated in the medullary nucleus raphe pallidus and obscurus, nucleus retroambiguus and in various subregions of the reticular formation including the nucleus reticularis ventralis, gigantocellularis, magnocellularis, pontis caudalis and pontis oralis. Significant numbers of neurons were also found in medial and lateral vestibular nuclei and in several presumed catecholamine-containing neurons of the dorsolateral pons. In the rat, but not in the cat, considerable numbers of cells are present in the mesencephalic reticular formation just lateral to the periaqueductal gray. In both species, some cells were found in the paraventricular nucleus of the hypothalamus. Brainstem cells projecting in the DLF were concentrated in the nucleus raphe magnus and in the adjacent nucleus reticularis magnocellularis, ipsilateral to the spared funiculus. Significant numbers of cells were found in the dorsolateral pons, differing somewhat in their distribution from those projecting in the VQ. DLF-projecting cells were also present in the ipsilateral Edinger-Westphal nucleus and periaqueductal grey contralateral red nucleus of the midbrain and in the ipsilateral hypothalamus. Smaller projections from other sites are described. These results are discussed in terms of the differential contribution of several brainstem neuronal groups, including the serotonergic nucleus, raphe magnus, the ventromedial reticular formation of the medulla, and various catecholamine-containing neurons of the dorsolateral pontine tegmentum to the analgesia produced by opiates and electrical brain stimulation.
有大量证据表明，脊髓背外侧索（DLF）包含对阿片类药物和脑干刺激产生的镇痛作用至关重要的下行通路。为了获得通过DLF投射到脊髓的脑干神经元的完整图谱，将大量辣根过氧化物酶（HRP）注射到猫和大鼠的腰骶脊髓中。这些注射是在胸中段损伤的尾侧进行的，该损伤仅保留了单个DLF或腹侧象限（VQ）；因此，只有那些轴突在保留的索中下行的神经元才会被标记。VQ中具有下行轴突的细胞集中在延髓中缝苍白核和中缝隐核、疑后核以及网状结构的各个亚区域，包括腹侧网状核、巨细胞网状核、大细胞网状核、尾侧脑桥核和嘴侧脑桥核。在内侧和外侧前庭核以及脑桥背外侧一些推测含有儿茶酚胺的神经元中也发现了大量神经元。在大鼠中，但在猫中未发现，中脑导水管周围灰质外侧的中脑网状结构中有大量细胞。在两个物种中，下丘脑室旁核中都发现了一些细胞。投射到DLF的脑干细胞集中在中缝大核以及与保留的索同侧的相邻大细胞网状核中。在脑桥背外侧发现了大量细胞，其分布与投射到VQ的细胞略有不同。投射到DLF的细胞也存在于同侧动眼神经副核、中脑导水管周围灰质对侧红核以及同侧下丘脑。还描述了来自其他部位的较小投射。根据几个脑干神经元群的不同贡献对这些结果进行了讨论，这些神经元群包括5-羟色胺能中缝大核、延髓腹内侧网状结构以及脑桥背外侧被盖中各种含儿茶酚胺的神经元对阿片类药物和脑电刺激产生的镇痛作用。
