Arvidsson U, Cullheim S, Ulfhake B, Luppi P H, Kitahama K, Jouvet M, Hökfelt T
Department of Neuroscience, Karolinska Institute, Stockholm, Sweden.
J Chem Neuroanat. 1994 Jul;7(1-2):3-12. doi: 10.1016/0891-0618(94)90003-5.
By use of the indirect immunofluorescence technique the distributions of 5-hydroxytryptamine (5-HT)-, substance P- and thyrotropin-releasing hormone (TRH)-immunoreactive (IR) neurons have been studied in the midline raphe nuclei and nucleus reticularis lateralis of the caudal brainstem (levels P18.3-P8.5; according to Berman (1968), in the cat, after treatment with colchicine. In addition, by use of the double-labelling technique, the coexistence between 5-HT-, substance P- and TRH-like immunoreactivity (LI) in these neurons was analysed. The results show that cell bodies in the midline raphe nuclei and nucleus reticularis lateralis contain 5-HT-, substance P- and TRH-LI. 5-HT-IR cells were more abundant than peptidergic neurons in all areas analysed. Quantitative estimations indicated that the total number of 5-HT-IR cells in the regions studied was about 17 x 10(3), while the corresponding numbers for substance P- and TRH-IR cells were 11 x 10(3) and 12 x 10(3), respectively. From double-labelled sections it was concluded that the vast majority of peptidergic cells also contained 5-HT-LI (87-100%). However, a subpopulation of 5-HT-IR neurons lacked peptide-LI (10-55%). The degree of coexistence varied with the brainstem level, in that neurons at more rostral locations showed a lower incidence of coexistence between 5-HT and peptide(s). The presence of all three compounds in one and the same cell body could also be demonstrated. In summary, 5-HT-, substance P- and TRH-IR cell bodies were encountered in medullary nuclei known to contain neurons with projection to the spinal cord. A high degree of coexistence between the compounds was demonstrated in these nuclei. The obtained results fit well with earlier studies on the patterns of distribution and peptide colocalization of 5-HT fibres in the spinal cord. The existence of biochemically distinct neuronal subpopulations within the 5-HT bulbospinal pathway is discussed.
运用间接免疫荧光技术，对猫经秋水仙碱处理后，在延髓脑干（P¹⁸.³ - P⁸.⁵水平；根据Berman（1968年））的中线中缝核和外侧网状核中5-羟色胺（5-HT）、P物质和促甲状腺激素释放激素（TRH）免疫反应性（IR）神经元的分布进行了研究。此外，运用双标记技术，分析了这些神经元中5-HT、P物质和TRH样免疫反应性（LI）之间的共存情况。结果表明，中线中缝核和外侧网状核中的细胞体含有5-HT、P物质和TRH-LI。在所有分析区域中，5-HT-IR细胞比肽能神经元更为丰富。定量估计表明，在所研究区域中5-HT-IR细胞的总数约为17×10³，而P物质和TRH-IR细胞的相应数量分别为11×10³和12×10³。从双标记切片得出的结论是，绝大多数肽能细胞也含有5-HT-LI（87 - 100%）。然而，一部分5-HT-IR神经元缺乏肽-LI（10 - 55%）。共存程度随脑干水平而异，即更靠前位置的神经元中5-HT与肽之间的共存发生率较低。在同一个细胞体中也能证明这三种化合物的存在。总之，在已知含有投射到脊髓的神经元的延髓核中发现了5-HT、P物质和TRH-IR细胞体。在这些核中证明了这些化合物之间的高度共存。所得结果与早期关于脊髓中5-HT纤维分布模式和肽共定位的研究结果非常吻合。讨论了5-HT延髓脊髓通路中生化性质不同的神经元亚群的存在。
