Baev K V, Esipenko V B
Department of Physiology of the Spinal Cord, A. A. Bogomoletz Institute of Physiology, Academy of Sciences of the Ukrainian S.S.R., Kiev.
Neuroscience. 1991;43(1):237-47. doi: 10.1016/0306-4522(91)90431-m.
Changes in the motor activity of the spinal locomotor generator evoked by tonic and phasic peripheral afferent signals during fictitious locomotion of both slow and fast rhythms were analysed in the cat. The tonic afferent inflow was conditioned by the position of the hindlimb. The phasic afferent signals were imitated by electrical stimulation of hindlimb nerves. The correlation between the kinematics of hindlimb locomotor movement and sensory inflow was investigated during actual locomotion. Reliable correlations between motor activity parameters during fictitious locomotion were revealed in cases of both slow and fast "locomotor" rhythms. The main difference between these cases was that correlations "duration-intensity" were positive in the first and negative in the second case. The functional role of "locomotor" pattern dependence on tonic sensory inflow consisted of providing stability for planting the hindlimb on the ground. For any investigated afferent input the phase moments in the "locomotor" cycle were found, in which an afferent signal caused no rearrangement in locomotor generator activity. These moments corresponded to the transitions between "flexion" and "extension" phases and to the bursts of integral afferent activity observed during real locomotion. The data obtained are compared with the results previously described for the scratching generator. The character of changes in "locomotor" activity in response to tonic and phasic sensory signals was similar to that of such changes in "scratching" rhythm in the case of fast "locomotion". Intensification of the "flexion" phase caused by phasic high-intensity stimulation of cutaneous afferents during low "locomotor" rhythm was changed to inhibition (such as observed during "scratching") when this rhythm was fast. It is concluded that the main regularities of peripheral afferent control for both the locomotor and scratching generators are the same. Moreover, these central pattern generators are just working regimes of a general spinal motor optimal control system containing the intrinsic model of limb movement dynamics. The consequences of this concept and ways of further research are discussed.
在猫进行慢节律和快节律的虚拟运动期间，分析了由强直和相位性外周传入信号诱发的脊髓运动发生器的运动活动变化。强直传入输入受后肢位置的调节。相位性传入信号通过电刺激后肢神经来模拟。在实际运动期间研究了后肢运动的运动学与感觉传入之间的相关性。在慢“运动”节律和快“运动”节律的情况下，均揭示了虚拟运动期间运动活动参数之间的可靠相关性。这些情况之间的主要差异在于，“持续时间 - 强度”相关性在第一种情况下为正，而在第二种情况下为负。“运动”模式对强直感觉传入的功能依赖作用在于为后肢在地面上的支撑提供稳定性。对于任何研究的传入输入，均发现了“运动”周期中的相位时刻，在这些时刻，传入信号不会引起运动发生器活动的重新排列。这些时刻对应于“屈曲”和“伸展”阶段之间的转换以及实际运动期间观察到的整体传入活动的爆发。将获得的数据与先前描述的搔抓发生器的结果进行了比较。在快“运动”情况下，响应强直和相位性感觉信号时“运动”活动的变化特征与“搔抓”节律中的此类变化特征相似。在低“运动”节律期间，皮肤传入的相位性高强度刺激引起的“屈曲”阶段增强，在该节律为快节律时转变为抑制（如在“搔抓”期间观察到的）。得出的结论是，运动发生器和搔抓发生器的外周传入控制的主要规律是相同的。此外，这些中枢模式发生器只是包含肢体运动动力学内在模型的一般脊髓运动最优控制系统的工作模式。讨论了这一概念的后果和进一步研究的方法。
