Properties of single central Ia afferent fibres projecting to motoneurones.
Properties of single central Ia afferent fibres projecting to motoneurones.
复制标题
投射到运动神经元的单个中央 Ia 传入纤维的特性。
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
G. Sypert
中科院分区：
文献类型：
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作者：
J. Munson;G. Sypert
1.用低阻抗、倾斜微管电极和棘波触发平均技术记录了猫腰骶髓内单个腓肠肌Ia传入纤维的动作诱发电位。2.从Ia纤维轴突电位记录细胞外出现短暂的三相为主的负电位。3.在Ia传入终止区域记录的终末电位表现为短暂的双相正负波，通常伴有额外的小波。4.局灶性突触电位，记录在内侧腓肠肌Ia传入终止区的细胞外，出现缓慢（约10毫秒持续时间）的负电位后，终端电位。5.在腓肠肌内侧Ia靶细胞中细胞内记录的兴奋性突触后电位在终末电位后表现为缓慢（持续时间约10 msec）的正电位。6.通过分析这些电位在脊髓中的时间进程，可以计算背索干轴突（50 - 60 m/sec）、主要侧支（8 - 19 m/sec）和终末支（0.2 - 1.0 m/sec）中的Ia传导速度。7.通过分析小腿三头肌运动神经元柱的范围来确定主要侧支的数量（9个或更少）及其沿脊髓的间距（平均值为沿着1071微米）。8.内侧腓肠肌Ia传入纤维的结构和功能特性进行了讨论，最近的单纤维解剖数据和本单纤维电生理数据。
1. Electrical potentials in the cat lumbosacral spinal cord evoked by the action of single medial gastrocnemius Ia afferent fibres were recorded using low impedance, bevelled micropipette electrodes and the spike triggered averaging technique. 2. Axonal potentials from the Ia fibres recorded extracellularly appeared as brief triphasic predominantly negative potentials. 3. Terminal potentials recorded in regions of Ia afferent termination appeared as brief diphasic positive‐negative waves, often with additional wavelets. 4. Focal synaptic potentials, recorded extracellularly in regions of the medial gastrocnemius Ia afferent termination, appeared as slow (about 10 msec duration) negative potentials following terminal potentials. 5. Excitatory post‐synaptic potentials, recorded intracellularly in Ia target cells of the medial gastrocnemius, appeared as slow (about 10 msec duration) positive potentials following terminal potentials. 6. Analysis of the temporal progression of these potentials through the spinal cord allowed calculations of the Ia conduction velocity in the dorsal funiculus stem axon (50‐60 m/sec), in major collateral branches (8‐19 m/sec) and in terminal branches (0.2‐1.0 m/sec). 7. The number of major collateral branches (nine or fewer) and their spacing along the spinal cord (1071 micron mean value) were determined by analysing the extent of the triceps surae motoneurone column. 8. The structural and functional properties of medial gastrocnemius Ia afferent fibres are discussed in relation to recent single fibre anatomical data and the present single fibre electrophysiological data.