Hirsch M D, Helke C J
Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
Neuroscience. 1988 May;25(2):625-37. doi: 10.1016/0306-4522(88)90264-3.
Whereas the neurochemistry of the peripheral autonomic nervous system has been well characterized, less is known concerning the neurotransmitters utilized by medullary projections onto sympathetic preganglionic neurons residing in the thoracolumbar spinal intermediolateral cell column. Retrograde transport of rhodamine-labeled fluorescent microspheres following discrete microinjection into the thoracic intermediolateral cell column was combined with immunohistochemistry to determine neuroanatomic location of thyrotropin-releasing hormone-immunoreactive neurons which project to the intermediolateral cell column in the rat. The ventromedial group of raphe nuclei including the nucleus raphe pallidus, obscurus, and magnus possessed the greatest number of medullary thyrotropin-releasing hormone-immunoreactive neurons which also contained rhodamine-labeled microspheres. High numbers of intermediolateral cell column-projecting thyrotropin-releasing hormone-immunoreactive neurons were also observed in nucleus reticularis paragigantocellularis lateralis and magnocellularis, the lateral reticular nucleus, and the superficial ventral (arcuate) medullary surface. Despite the observations that nucleus reticularis gigantocellularis, paramedianus, and ventralis pars beta project to the intermediolateral cell column, double-labeled cells were not observed in these nuclei. Furthermore, whereas the nucleus reticularis magnocellularis and gigantocellularis, and the lateral reticular nucleus displayed strong ipsilateral predominance in projecting to the intermediolateral cell column, other medullary reticular and raphe nuclei displayed bilateral projections. The present findings support the hypothesis that thyrotropin-releasing hormone-containing neurons in the ventral medulla project to the intermediolateral cell column, and may influence sympathetic preganglionic neurons.
虽然外周自主神经系统的神经化学已得到充分表征，但对于延髓投射到位于胸腰段脊髓中间外侧细胞柱的交感神经节前神经元所利用的神经递质，人们了解较少。将罗丹明标记的荧光微球在离散微注射到胸段中间外侧细胞柱后进行逆行运输，并与免疫组织化学相结合，以确定向大鼠中间外侧细胞柱投射的促甲状腺激素释放激素免疫反应性神经元的神经解剖位置。包括中缝苍白核、中缝隐核和中缝大核在内的中缝核腹内侧组拥有数量最多的延髓促甲状腺激素释放激素免疫反应性神经元，这些神经元也含有罗丹明标记的微球。在外侧旁巨细胞网状核、巨细胞网状核、外侧网状核和腹侧浅表（弓状）髓质表面也观察到大量向中间外侧细胞柱投射的促甲状腺激素释放激素免疫反应性神经元。尽管观察到巨细胞网状核、旁正中网状核和腹侧β部投射到中间外侧细胞柱，但在这些核中未观察到双标记细胞。此外，虽然巨细胞网状核和外侧网状核在向中间外侧细胞柱投射时表现出强烈的同侧优势，但其他延髓网状核和中缝核表现出双侧投射。目前的研究结果支持这样的假设，即延髓腹侧含促甲状腺激素释放激素的神经元投射到中间外侧细胞柱，并可能影响交感神经节前神经元。
