Central terminations of muscle afferents on motoneurones in the cat spinal cord.
Central terminations of muscle afferents on motoneurones in the cat spinal cord.
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猫脊髓运动神经元上肌肉传入的中枢终止。
DOI：
10.1113/jphysiol.1976.sp011587
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
J. Iles
中科院分区：
文献类型：
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作者：
J. Iles
猫腰髓初级传入神经轴突的椎管内分支已通过填充钴，然后沉淀为硫化钴和银强化而显示。2.初级传入侧支，达到腹角有髓鞘，轴突直径约2妈妈。最多4个（平均1个）侧支发生在腹角内的节点。最细的分支直径小于1 μ m。3.最细的分支在神经细胞上形成突触终扣。观察到的一个传入神经和运动神经元（突触结构）之间的总关联包括多达6个终扣（平均1 - 85）。构成突触结构的终扣通常紧密地位于索马或树突上，但有时沿沿着60 μ m以上的树突散布。据推测，运动神经元上的这些单突触结构由肌梭传入形成。4.突触结构的总接触面积与其在运动神经元上的位置之间没有相关性。5.本研究利用运动神经元的计算机模型，探讨了多突触接触对突触定位电生理估计的影响。得出的结论是，所观察到的扩散构成突触结构的终扣不会显着影响远端突触的距离分配，但可能会导致一些近端树突结构被错误地归类为体细胞。
Intraspinal branches of primary afferent axons in the cat lumbar cord have been revealed by filling then with cobalt, followed by precipitation as cobalt sulphide and silver intensification. 2. Primary afferent collaterals which reached the ventral horn were myelinated and had axon diameters of around 2 mum. Up to four (mean 1) side branches occurred at nodes within the ventral horn. The finest branches were less than 1 mum in diameter. 3. The finest branches formed synaptic boutons on nerve cells. The total observed association between one afferent and a motoneurone (synaptic structure) consisted of up to six boutons (mean 1‐85). The boutons constituting a synaptic structure were usually located close together on the soma or dendrites, but sometimes were spread along more than 60 mum of dendrite. It was assumed that these monosynaptic structures on moto‐neurones were formed by muscle spindle afferents. 4. There was no correlation between the total contact area of a synaptic structure and its location on a motoneurone. 5. A computer model of the motoneurone was used to investigate the effect of multiple synaptic contact on electrophysiological estimates of synaptic location. It was concluded that the observed spread of boutons making up a synaptic structure would not significantly affect distance allocation of distal synapses but could lead to some proximal dendrite structures being incorrectly classified as somatic.