Modulation of stretch-evoked reflexes in single motor units in human masseter muscle by experimental pain
Modulation of stretch-evoked reflexes in single motor units in human masseter muscle by experimental pain
复制标题
实验性疼痛对人类咬肌单个运动单位牵张诱发反射的调节
作者：
P. Svensson;T. Miles;T. Graven‐Nielsen;L. Arendt
抽象的。肌肉疼痛和下颌运动功能之间的相互作用近年来已被研究，但疼痛对短潜伏期牵张反射的调制性质尚未完全了解。在这项研究中，在单一的低阈值运动单位，保持在一个恒定的频率放电，之前，期间和之后的实验性疼痛的诱导在一个咬肌的控制性高渗盐水输注拉伸反射反应进行了测量。在近单突触潜伏期的疼痛肌肉中的单个运动单位中唤起反射反应的概率平均降低约20%。然而，整体反射反应的表面肌电图的同侧和对侧咬肌疼痛时更大。这显然是疼痛引起的两块肌肉的运动神经元池中的刺激前活动增加的次级反应，因为运动神经元兴奋性增加可能促进牵张反射。它的结论是，最有可能的解释低阈值咬肌运动单位在实验性疼痛的反射反应减少是一个强直性减少的梭电机驱动咬肌梭。
Abstract. The interaction between muscle pain and motor function of the jaw has been examined in recent years, but the nature of the modulation of the short-latency stretch reflex by pain is not fully understood. In this study, the reflex responses to stretch were measured in single low-threshold motor units that were kept discharging at a constant frequency, before, during and after the induction of experimental pain in one masseter muscle by controlled infusion of hypertonic saline. The probability of evoking a reflex response in individual motor units in the painful muscle at near-monosynaptic latency was reduced by a mean of about 20%. However, the overall reflex response in the surface electromyogram of both the ipsi- and contralateral masseter muscles was greater during pain. This was apparently a secondary response to the pain-induced increase in pre-stimulus activity in the motoneurone pools of both muscles, because increased motoneurone excitability may facilitate stretch reflexes. It is concluded that the most likely explanation for the reduced reflex response of low-threshold masseter motor units during experimental pain is a tonic reduction in the fusimotor drive to the masseter spindles.
影响因子：
2.1
作者：
LUND, JP;DONGA, R;STOHLER, CS
通讯作者：
STOHLER, CS