Ribot-Ciscar E, Roll J P
Laboratoire de Neurobiologie Humaine, UMR CNRS 6562 - Université de Provence, Marseille, France.
Brain Res. 1998 Apr 27;791(1-2):167-76. doi: 10.1016/s0006-8993(98)00092-4.
The proprioceptive feedback associated with the performance of even quite simple movements is always generated by the whole set of muscles subjected to mechanical deformation (lengthening, shortening, contraction, etc.) during that particular movement. The question was addressed here as to how muscle spindle feedbacks arising from agonist and antagonist muscles may contribute to the coding of movement parameters such as the direction and velocity. For this purpose, the activity of single muscle spindle afferents located in the lateral peroneal nerve was analysed using the microneurographic technique, in human subjects performing repetitive voluntary movements, i.e., plantar/dorsal flexions of the ankle, at three different velocities (3, 4.5 and 6 degrees/s). The data obtained suggest that in humans, the direction of a slow movement may be specified on the basis of the spindle discharge rate, which is greater in the stretched than in the shortened muscle, and that the velocity of this movement might be correlated with the difference between the spindle activity occurring in the agonist and antagonist muscles. These neurophysiological data are in agreement with the results of previous psychophysical studies showing for example that a sensation of illusory movement can be elicited only when there exists an imbalance between the agonist versus antagonist vibration-induced Ia inputs. In addition, the greater the difference between the vibration frequencies applied to the two antagonist muscles, the higher the perceived movement velocity was found to be. All in all, joint movement perception seems to result from the co-processing by the central nervous system of the multiple spindle feedbacks originating from the whole set of muscles involved in the performance of a movement.
即使是相当简单的动作执行过程中所伴随的本体感觉反馈，始终是由在该特定动作期间受到机械变形（拉长、缩短、收缩等）的整套肌肉产生的。这里探讨的问题是，来自主动肌和拮抗肌的肌梭反馈如何有助于对运动参数（如方向和速度）进行编码。为此，在人类受试者进行重复性自主运动（即踝关节的跖屈/背屈）时，以三种不同速度（3、4.5和6度/秒），使用微神经图技术分析位于腓骨外侧神经中的单根肌梭传入纤维的活动。获得的数据表明，在人类中，缓慢运动的方向可能基于肌梭放电率来确定，在伸展的肌肉中放电率大于缩短的肌肉，并且该运动的速度可能与主动肌和拮抗肌中发生的肌梭活动差异相关。这些神经生理学数据与先前的心理物理学研究结果一致，例如，只有当主动肌与拮抗肌振动诱发的Ia输入之间存在不平衡时，才会引发虚幻运动的感觉。此外，发现施加到两块拮抗肌上的振动频率差异越大，感知到的运动速度就越高。总而言之，关节运动感知似乎是由中枢神经系统对源自参与动作执行的整套肌肉的多个肌梭反馈进行协同处理的结果。
