Gyimesi-Pelczer K, Kocsis B
National Institute of Neurosurgery, Budapest, Hungary.
J Auton Nerv Syst. 1998 Apr 30;69(2-3):122-6. doi: 10.1016/s0165-1838(98)00011-3.
According to anatomical data, preganglionic neurons projecting to the kidney via sympathetic ganglia occupy a wide range of adjacent segments in the thoracolumbar spinal cord, from Th7 to L2. Since, however, the majority of preganglionic neurons is silent at resting states, the active segments indeed transmitting sympathetic activity, at rest, may be different. In the present experiments, the spontaneous sympathetic activity was recorded before and after the sympathetic trunk and white rami (WR) Th8-L3 were cut in a sequential manner. The step-by-step changes in the power of renal nerve discharge were estimated and used for mapping tonic renal outflow to the spinal cord. We found that powerful activity comprising 70-95% of the power of control recordings remained after eliminating the input from Th1-Th12, indicating that thoracic spinal cord including segments that contain the largest number of cells projecting to renal postganglionic neurons contributes relatively weakly to tonic renal nerve activity. It appeared that resting sympathetic nerve discharge was predominantly maintained by the caudalmost division of the renal preganglionic neuron population since the largest decrease in nerve power occurred after severing WR Th13, L1, and L2. These findings suggest that the 'active segmental map' of preganglionic neurons controlling a certain organ at rest does not necessarily match the distribution of the total population of neurons projecting to the same effector.
根据解剖学数据，经交感神经节投射至肾脏的节前神经元占据胸腰段脊髓中从胸7至腰2的广泛相邻节段。然而，由于大多数节前神经元在静息状态下是沉默的，因此在静息时实际传递交感神经活动的活跃节段可能有所不同。在本实验中，在依次切断胸8至腰3交感干和白交通支（WR）之前和之后记录了自发交感神经活动。估计肾神经放电功率的逐步变化，并用于绘制脊髓的紧张性肾传出通路图。我们发现，在消除胸1至胸12的输入后，仍保留了占对照记录功率70%至95%的强大活动，这表明包括投射至肾节后神经元的细胞数量最多的节段在内的胸段脊髓对紧张性肾神经活动的贡献相对较小。似乎静息交感神经放电主要由肾节前神经元群体最尾端的分支维持，因为在切断胸13、腰1和腰2的白交通支后，神经功率下降最大。这些发现表明，在静息时控制某一器官的节前神经元的“活跃节段图谱”不一定与投射至同一效应器的神经元总数的分布相匹配。
