Gregory J E
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Exp Brain Res. 1990;81(3):602-8. doi: 10.1007/BF02423510.
In one medial gastrocnemius muscle of each of several cats, the response was recorded of a single tendon organ to the contraction of a single motor unit which strongly excited the receptor. The motor unit was depleted of its glycogen and the depleted muscle fibres identified in PAS-stained transverse sections. The site of maximum tendon organ sensitivity was marked and the tendon organ identified in the same sections. Five pairs of tendon organs and motor units were studied completely. Each tendon organ was found to have one or two (mean 1.6) depleted muscle fibres attached to it, included in the bundle of fibres attached to the end (mean no. 14.4) and side (mean no. 5.6) of the tendon organ. A correlation was found between tendon organ discharge rate and the tension calculated from cross-sectional area measurements of the depleted muscle fibres attached to the tendon organ, with variation between individual pairs of tendon organs and motor units. One estimate of the average sensitivity of the sample was 28 imp/s/mN. A nearly linear discharge rate vs. tension relation was found for single tendon organ and motor unit pairs when tension was graded during a series of fatiguing contractions. Under these conditions the sensitivity, measured as the slope of the relation between discharge rate and motor unit tension recorded at the common tendon, varied between 0.11 and 0.30 imp/s/mN for 6 pairs.
在几只猫的每只猫的一块内侧腓肠肌中，记录了单个腱器官对强烈兴奋该感受器的单个运动单位收缩的反应。使该运动单位的糖原耗尽，并在过碘酸希夫（PAS）染色的横切片中识别出耗尽糖原的肌纤维。标记出腱器官最大敏感性的部位，并在同一切片中识别出腱器官。对五对腱器官和运动单位进行了完整的研究。发现每个腱器官都有一或两条（平均1.6条）与其相连的耗尽糖原的肌纤维，这些肌纤维包含在附着于腱器官末端（平均14.4条）和侧面（平均5.6条）的纤维束中。发现腱器官放电率与根据附着于腱器官的耗尽糖原的肌纤维横截面积测量计算出的张力之间存在相关性，不同的腱器官和运动单位对之间存在差异。该样本平均敏感性的一个估计值为28次冲动/秒/毫牛顿。当在一系列疲劳收缩过程中对张力进行分级时，发现单个腱器官和运动单位对的放电率与张力之间存在近乎线性的关系。在这些条件下，以在共同腱处记录的放电率与运动单位张力之间关系的斜率来衡量的敏感性，6对样本的敏感性在0.11至0.30次冲动/秒/毫牛顿之间变化。
