Morphological analysis of the external anal sphincter motor nerve and its motoneurons in the cat
Morphological analysis of the external anal sphincter motor nerve and its motoneurons in the cat
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DOI：
10.1111/j.1447-073x.2008.00238.x
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发表时间：
2008-12-01
影响因子：
1.2
通讯作者：
Sato, Kenji
中科院分区：
文献类型：
--
作者：
Muramatsu, Ken;Sasaki, Sei-Ichi;Sato, Kenji
为了研究猫控制肛门外括约肌张力的脊髓神经回路，我们检测了肛门外括约肌运动纤维及其运动神经元（MN）的大小分布，并检测了肛门外括约肌肌肉组织中肌梭的存在。用辣根过氧化物酶标记细胞后，观察传入纤维变性后EAS运动纤维的大小分布，测定其MN。这两种分布都是单峰的，因此表明很难区分α和潜在的γ MN；但是在肌肉组织中没有发现肌纺锤体。包括脊髓反射的性质和作用在内的东亚脊髓控制张力的机制尚不清楚。有人认为，肛管中的非梭形感觉受体可能提供反射回路的感觉成分，有助于这种张力。
To investigate the spinal neural circuitry that controls the tonus of the external anal sphincter (EAS) in the cat, the size distribution of EAS motor fibers and their motoneurons (MN) was examined, and the presence of muscle spindles in EAS musculature was also tested for. The size distribution of EAS motor fibers was examined after degeneration of afferent fibers and that of their MN was measured, after labeling the cells with horseradish peroxidase. Both distributions were unimodal, thereby demonstrating the difficulty of distinguishing between alpha and potential gamma MN; but muscle spindles were not found in the musculature. Mechanisms underlying the spinally controlled tonus of the EAS remain unclear, including the nature and role of spinal reflexes. It is argued that non-spindle sensory receptors in the anal canal may provide the sensory component of a reflex circuit that contributes to this tonus.