MORPHOLOGICAL ANALYSIS OF EXTERNAL URETHRAL AND EXTERNAL ANAL-SPHINCTER MOTONEURONS OF CAT
MORPHOLOGICAL ANALYSIS OF EXTERNAL URETHRAL AND EXTERNAL ANAL-SPHINCTER MOTONEURONS OF CAT
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DOI：
10.1002/cne.903490209
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发表时间：
1994-11-08
影响因子：
2.5
通讯作者：
SASAKI, M
中科院分区：
文献类型：
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作者：
SASAKI, M
以前的电生理学研究表明，轴突传导速度，输入电阻和大小的运动神经元之间有一个共同的相关性，无论由运动神经元支配的肌肉类型和树突状树枝化是不发达的括约肌比后肢运动神经元。要验证前面的建议，请使用单元格。在戊巴比妥麻醉的猫中，用辣根过氧化物酶进行细胞内标记后，研究了外尿道括约肌（EUS）和外肛门括约肌（EAS）运动神经元的体、轴突和树突。所有的细胞体都位于Onuf的细胞核内。索马直径（19.7-50.0 μ m）与轴突传导速度呈正相关，这两个变量的曲线是从后肢a-运动神经元获得的类似曲线外推的，支持了先前报告的建议。一半的运动神经元有经常性的轴突侧支，终止于Onuf核和第八层的腹侧缘。有侧枝的细胞胞体直径明显大于无侧枝的细胞胞体直径。树突向五个方向延伸：背侧、内侧、外侧、喙侧和尾侧。背侧定向树突的EUS和EAS运动神经元当然在第七层向中间外侧核，和EAS运动神经元的树突进一步向中间内侧核延伸。长的树突直接rostrally或尾内Onuf的核，更显着的EUS运动神经元。与EUS相比，EAS运动神经元具有较长的终支和相对较大的终支数量以及树突的总长度和表面积。其中，枝晶表面积和枝晶体积与一级枝晶直径密切相关。后者的关系是几乎相同的EUS，EAS，和后肢α和γ运动神经元。树突与索马表面积比的大值（EUS中为31，EAS中为50）表明与后肢运动神经元相当的发育良好的树突分支。EUS和EAS运动神经元的子体直径之和Sigma（3/2）与母体直径的3/2幂之比分别为0.99和1.08，表明在分支点满足3/2幂约束，Rall的等效圆柱模型适用于括约肌运动神经元。(C)1994 Wiley-Liss，Inc.
A previous electrophysiological study suggested that there is a common correlation among axonal conduction velocity, input resistance, and size of motoneurones regardless of the muscle type innervated by a motoneurone and that the dendritic arborization is less developed in sphincter than in hindlimb motoneurones. To verify the previous suggestions, cell. bodies, axons, and dendrites of external urethral sphincter (EUS) and external anal sphincter (EAS) motoneurones were studied after intracellular labelling with horseradish peroxidase in cats anaesthetised with pentobarbitone. All the cell bodies were located in Onuf's nucleus. The soma diameter (19.7-50.0 mu m) was positively correlated with the axonal conduction velocity, and the plots of these two variables were extrapolations from similar plots obtained for hindlimb a-motoneurones, supporting the suggestion of the preceding report. Half of motoneurones had recurrent axon collaterals, which terminated within Onuf's nucleus and the ventral border of lamina VIII. The diameter of the cell body with collaterals was significantly larger than that without collaterals. Dendrites extended in five directions: dorsal, medial, lateral, rostral, and caudal. Dorsally directed dendrites of both EUS and EAS motoneurones coursed in lamina VII toward the intermediolateral nucleus, and dendrites of EAS motoneurones further extended toward the intermediomedial nucleus. Long dendrites directed rostrally or caudally within Onuf's nucleus, more prominently in EUS motoneurones. EAS motoneurones had longer end branches and relatively larger number of end branches and summed length and surface area of a dendrite compared with EUS. Among relations, the dendritic surface area and the dendritic volume were tightly correlated with the diameter of the first-order dendrite. The latter relation was almost identical between EUS, EAS, and hindlimb alpha- and gamma-motoneurones. The large values for the dendritic-to-soma surface area ratio (31 in EUS, 50 in EAS) indicated the well-developed dendritic arborization comparable to hindlimb motoneurones. The ratio of sum Sigma(daughter diameter)(3/2) to the 3/2 power of the parent diameter was 0.99 in EUS and 1.08 in EAS motoneurones, indicating that the 3/2 power constraint at branching points is well satisfied, and Rall's equivalent-cylinder model is applicable to sphincter motoneurones. (C) 1994 Wiley-Liss, Inc.