Van Dongen P A, Hökfelt T, Grillner S, Verhofstad A A, Steinbusch H W, Cuello A C, Terenius L
J Comp Neurol. 1985 Apr 22;234(4):501-22. doi: 10.1002/cne.902340408.
The distribution of some putative neurotransmitters was investigated in the spinal cord and spinal ganglia of the lamprey, a primitive vertebrate, by using immunohistochemical methods. In the spinal cord a midline row of 5-hydroxytryptamine (5-HT)-immunoreactive neurons was present immediately ventral to the central canal over the entire length of the spinal cord. The ventral processes of these neurons formed a dense ventromedial plexus of varicosities. In the dorsal, lateral, and ventral spinal axon columns, several longitudinal 5-HT fibers were present. After chronic spinal transections the distribution of 5-HT fibers was unchanged; it is therefore concluded that there was no substantial descending 5-HT contribution and that the spinal 5-HT neurons supplied the regional 5-HT innervation. The spinal 5-HT cells sent fibers into the dorsal and ventral roots; 5-HT cell bodies and fibers were also present in the spinal dorsal root ganglia, in their dorsal, ventral, and lateral nerve branches, and in the dorsal and ventral branches of the ventral roots. Neurons and fibers containing peptides of the tachykinin (TK) family (to which, amongst others, substance P belongs) were found in the spinal cord. TK neurons in the spinal cord supplied the local TK innervation, as well as TK fibers in the dorsal and ventral roots. Fibers have been found containing either TK, or 5-HT, or both compounds. Neurons containing neuropeptide-Y (NPY)-immunoreactive material were present in a medial column just dorsal to the central canal. The NPY neurons have longitudinal, mainly descending, fibers that provide the local NPY innervation of the lamprey spinal cord. The present results provide evidence for local spinal systems containing 5-HT, TK, 5-HT and TK, or NPY, but in contrast to mammals, these compounds do not seem to arise from supraspinal neurons.
运用免疫组织化学方法，对原始脊椎动物七鳃鳗脊髓和脊神经节中一些假定神经递质的分布情况进行了研究。在脊髓中，一条5-羟色胺（5-HT）免疫反应阳性神经元的中线排位于脊髓全长中央管正腹侧。这些神经元的腹侧突起形成了一个密集的含曲张体的腹内侧丛。在脊髓背侧、外侧和腹侧轴突柱中，有几条纵向的5-HT纤维。慢性脊髓横断后，5-HT纤维的分布未变；因此得出结论，不存在实质性的下行5-HT贡献，脊髓5-HT神经元提供局部5-HT神经支配。脊髓5-HT细胞向背根和腹根发出纤维；5-HT细胞体和纤维也存在于脊髓背根神经节、其背侧、腹侧和外侧神经分支以及腹根的背侧和腹侧分支中。在脊髓中发现了含有速激肽（TK）家族肽（P物质也属于该家族）的神经元和纤维。脊髓中的TK神经元提供局部TK神经支配，以及背根和腹根中的TK纤维。已发现含有TK、5-HT或两者的纤维。含有神经肽Y（NPY）免疫反应性物质的神经元存在于中央管背侧的内侧柱中。NPY神经元有纵向的、主要是下行的纤维，为七鳃鳗脊髓提供局部NPY神经支配。目前的结果为脊髓中含有5-HT、TK、5-HT和TK或NPY的局部系统提供了证据，但与哺乳动物不同，这些化合物似乎并非来自脊髓上神经元。
