Pilowsky P M, de Castro D, Llewellyn-Smith I, Lipski J, Voss M D
Department of Physiology, School of Medicine, University of Auckland, New Zealand.
J Neurosci. 1990 Apr;10(4):1091-8. doi: 10.1523/JNEUROSCI.10-04-01091.1990.
In anesthetized cats, phrenic motoneurons were intracellularly labeled with HRP. Immunohistochemistry was used to localize serotonin-like immunoreactivity that was present in numerous boutons and nerve fibers within the ventral horn of the C5 spinal segment. Immunoreactive boutons were frequently found in apposition to phrenic motoneurons, but these close contacts were more common on the dendrites than the cell body. At the electron microscope level, serotonin-immunoreactive boutons were found to make synapses with well-defined postsynaptic densities on proximal and distal dendrites of phrenic motoneurons. These results suggest that serotonin-containing neurons may directly affect the excitability of phrenic motoneurons, mainly through an input onto their extensive dendritic trees.
在麻醉猫中，膈运动神经元用辣根过氧化物酶进行细胞内标记。采用免疫组织化学法定位5-羟色胺样免疫反应性，其存在于C5脊髓节段腹角内的大量终扣和神经纤维中。免疫反应性终扣经常发现与膈运动神经元相邻，但这些紧密接触在树突上比在细胞体上更常见。在电子显微镜水平上，发现5-羟色胺免疫反应性终扣与膈运动神经元近端和远端树突上明确的突触后致密物形成突触。这些结果表明，含5-羟色胺的神经元可能主要通过作用于其广泛的树突来直接影响膈运动神经元的兴奋性。
