• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>The Journal of Physiology >Evidence from the use of vibration during procaine nerve block that the spindle group II fibres contribute excitation to the tonic stretch reflex of the decerebrate cat
【2h】

Evidence from the use of vibration during procaine nerve block that the spindle group II fibres contribute excitation to the tonic stretch reflex of the decerebrate cat

机译：在普鲁卡因神经阻滞期间使用振动的证据表明纺锤体II类纤维有助于激发去脑猫的强直反射

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

1. Experiments have been performed to test the hypothesis that the group II fibres from the secondary endings of the muscle spindle provide an excitatory contribution to the tonic stretch reflex of the decerebrate cat. They have consisted of studying the effect of fusimotor paralysis by procaine, applied to the muscle nerve, on the reflex response to the combined stimuli of stretch (5-9 mm at 5 mm/sec) and of high-frequency vibration (100-150 Hz, 150 μm).2. The reflex response to the combined stimuli was found to be paralysed in two distinct stages which paralleled those of the ordinary stretch reflex described earlier. The two phases of paralysis may be attributed to an early paralysis of the γ efferents followed by a later paralysis of the Ia afferents and α motor fibres. However, the Ia discharges elicited by the combined stimuli, unlike those elicited by simple stretch, should have remained unchanged on γ efferent paralysis since the Ia firing frequency may be presumed to have been clamped at the vibration frequency by the occurrence of one-to-one `driving'. The early reduction of the response to the combined stimuli may thus be attributed to the removal of a stretchevoked autogenetic excitatory input other than that long known to be provided by the Ia pathway. This supports the view that the spindle group II fibres have such an action, since their firing will be appropriately reduced on γ efferent paralysis by removal of their pre-existing fusimotor bias; there is no evidence for the existence of any other group of fibres with the right properties.3. Recording of compound action potentials and of single units confirmed the great sensitivity of the γ efferents to procaine but showed that the group II fibres were nearly as resistant as the Ia fibres and α motor fibres.4. The reliability of one-to-one driving of the Ia discharges by the vibration was tested in control experiments in which the reflex was elicited by an asymmetrical vibratory waveform with a rapid rising phase (1·5 or 1·9 msec at 140 Hz) and a slower falling phase. Recordings from single units showed that the use of this wave form greatly diminished any tendency to double driving (2 spikes/cycle of vibration) during the dynamic phase of stretch and never elicited it during the static phase of stretch when the reflex measurements were made. These `pulsed' vibrations elicited reflex contractions which were of the same general size and which were paralysed in the same two phases by procaine as those elicited by sinusoidal vibrations. This eliminates the possibility that the early phase of paralysis might have been due to conversion of the pattern of Ia firing from double to single driving on γ efferent paralysis.5. Wedensky inhibition of the afferent fibres could not be held responsible for the early phase of paralysis.6. The results are taken to strengthen the hypothesis that the spindle group II fibres contribute excitation rather than inhibition to the stretch reflex. The particular support derived from the present experiments is that all measurements of the size of the reflex at various times were made with the muscle at the same length so that the findings cannot be attributed to the tension-length properties of muscle. The detailed mechanism of the excitation, however, remains to be established and certain of the present findings suggest that it may not be a direct one.
机译：1.已经进行了实验以检验以下假设：来自肌肉纺锤次要末端的II组纤维为去脑猫的强直性反射提供了兴奋性贡献。他们研究了普鲁卡因在肌肉神经上引起的运动性麻痹对联合拉伸（5-9mm，5mm / sec）刺激和高频振动（100-150）的反射反应的影响。 Hz，150μm）.2。发现对组合刺激的反射反应在两个不同的阶段瘫痪，这与先前描述的普通拉伸反射的反应平行。麻痹的两个阶段可归因于γ传出的早期麻痹，然后是Ia传入和α运动纤维的后来麻痹。但是，与简单伸展引起的放电不同，组合刺激引起的Ia放电在γ传出的麻痹中应保持不变，因为可以推测Ia激发频率被一对一的发生钳制在振动频率上。一“开车”。因此，对组合刺激的反应的早期减少可归因于除了长期以来已知由Ia途径提供的那些之外，消除了由拉伸诱发的自体兴奋性输入。这支持了纺锤组II纤维具有这种作用的观点，因为通过消除它们先前存在的旋转运动偏斜，将在γ发出的瘫痪中适当地减少其燃烧。没有证据表明存在其他任何具有正确特性的纤维。3。复合动作电位和单个单位的记录证实了γ传出对普鲁卡因的敏感性高，但显示II组纤维几乎与Ia纤维和α运动纤维一样耐力。4。在控制实验中测试了通过振动一对一驱动Ia放电的可靠性，在控制实验中，反射是由具有快速上升相位（在140 Hz下为1·5或1·9毫秒）的不对称振动波形引起的和较慢的下降阶段来自单个单元的记录表明，使用此波形可大大减少在拉伸动态阶段加倍驱动的任何趋势（2个尖峰/振动周期），并且在进行反射测量时，在拉伸静态阶段从不会引发这种趋势。这些“脉冲”振动引起反射收缩，该收缩收缩具有相同的一般大小，并且与正弦振动引起的反射收缩一样，被普鲁卡因在相同的两个阶段瘫痪。这消除了麻痹的早期阶段可能是由于γ发射麻痹将Ia发射模式从双重驱动转换为单一驱动的可能。5。 Wedensky对传入纤维的抑制不能导致麻痹的早期阶段。6。得出的结果加强了这样的假说，即纺锤组II纤维对拉伸反射起刺激作用而不是抑制作用。从本实验中得到的特殊支持是，对不同时间反射大小的所有测量都是在相同长度的肌肉上进行的，因此发现不能归因于肌肉的拉伸长度特性。然而，激发的详细机理尚待确定，目前的某些发现表明它可能不是直接的。

著录项

相似文献

  • 外文文献
代理获取

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号