THE ROLE OF THE MOTOR CORTEX IN THE CONTROL OF VIGOR OF LOCOMOTOR MOVEMENTS IN THE CAT
THE ROLE OF THE MOTOR CORTEX IN THE CONTROL OF VIGOR OF LOCOMOTOR MOVEMENTS IN THE CAT
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DOI：
10.1113/jphysiol.1993.sp019499
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发表时间：
1993-02-01
影响因子：
5.5
通讯作者：
SIROTA, MG
中科院分区：
文献类型：
--
作者：
BELOOZEROVA, IN;SIROTA, MG
1. 用可移动的清漆绝缘钨微电极记录了4只自由活动的成年猫的细胞外运动皮层（MC）单个神经元的脉冲活动。猫在实验箱中行走，在摇摆或站立阶段的步骤循环中有不同的负载。在10 ~ 100步内，测量每个神经元的平均放电率（mR）和频率调制深度（dM）。在10度倾斜地板上坡行走时，记录了31个细胞（包括18个锥体束神经元）的活动。与在平地上行走相比，在上坡运动中68%的神经元的mR和77%的神经元的dM变化不到20%。同样在10度斜面下坡行走时，这些神经元的活动也被记录下来。与在平地上行走相比，下坡运动中69%的神经元的mR和78%的神经元的dM变化小于20%。将23个（左半球）细胞（16个ptn）在地板向右(R)和向左(L)摆动时的活动与在稳定表面上运动时的活动进行比较。r -步骤中83%的细胞mR和83%的细胞dM， l -步骤中分别有82%和77%的细胞mR和dM变化小于20%。研究了37个细胞在不同运动速度下的活动。与中速运动相比，在快速和缓慢运动中，68%的细胞mR和38%的细胞dM变化小于20%。46%的神经元dM随慢走转快走而升高。在每个肘关节远端施加85 g负荷的运动过程中，记录31个MC细胞的活动。52%的神经元的mR和48%的神经元的dM变化超过20%。我们分步骤研究了动物翻身时28个细胞（6个ptn）的活性。记录的MC对侧肢体在一个方向的转身步中摆动较短（条件1），在相反方向的转身步中摆动较长（条件2）。在条件1和条件1中，50%的细胞mR和50%的细胞dM。在条件2 -中，分别有52%和59%的细胞变化超过20%。在上坡和下坡运动、沿摇摆地板运动和转弯运动时，神经元放电峰值相对于步进周期的位置与正常行走时相同。在前肢负重运动时，13%的细胞放电速率峰值位置发生了变化，在不同速度下行走时，30%的细胞放电速率峰值位置发生了变化。MC的失活或取消并不妨碍上述任务的执行。由此可见，运动皮层并不是运动适应各种负荷所必需的，但运动皮层在当前运动过程中接收运动功率变化的信息，这些信息可能用于新任务中的运动纠正。
1. The impulse activity of single neurones in the motor cortex (MC) was recorded extracellularly using movable varnish-insulated tungsten microelectrodes in four adult freely moving cats. The cats walked inside the experimental box with various loadings in the swing or stance phases of the step cycle. The mean discharge rate (mR) and the depth of frequency modulation (dM) in each neurone were estimated over 10-100 steps.2. The activity of thirty-one cells (including eighteen pyramidal tract neurones (PTNs)) was recorded during uphill walking on a 10 deg inclined floor. The mR in 68 %, and the dM in 77 % of neurones changed by less than 20 % during uphill locomotion compared to walking on a level surface.3. The activity of the same neurones was also recorded during downhill walking, also on a 10 deg inclined plane. The mR in 69 % and the dM in 78 % of neurones changed by less than 20 % during downhill locomotion compared with walking on a level surface.4. The activity of twenty-three (the left hemisphere) cells (sixteen PTNs) during walking with the floor swaying to the right (R) and to the left (L) was compared to activity during locomotion on a stable surface. The mR in 83 % and the dM in 83 % of cells in R-steps, and in 82 and 77 % of cells, respectively, in L-steps changed by less than 20 %.5. The activity of thirty-seven cells was studied during locomotion at various speeds. The mR in 68 % and the dM in 38 % of cells changed by less than 20 % during fast and slow locomotion compared to middle-speed locomotion. The dM in 46 % of neurones increased with the transfer from slow to fast walking.6. The activity of thirty-one MC cells was recorded during locomotion with loads of 85 g attached to the distal part of each elbow. The mR in 52 % and the dM in 48 % of neurones changed by more than 20 %.7. The activity of twenty-eight cells (six PTNs) was studied in steps when an animal turned. The swing of the limb contralateral to the recorded MC was shorter (condition 1) in turning steps in one direction, and was longer (condition 2) in turning steps in the opposite direction. The mR in 50 % and the dM in 50 % of cells in condition 1 and.in 52 % and 59 %, respectively, of cells in condition 2 - changed by more than 20 %.8. The position of the neurones' peak discharge rate, relative to the step cycle, was as for normal walking during both uphill and downhill locomotion, during locomotion along a swaying floor and through the turns. During locomotion with the extra-loaded forelimbs, the position of the peak discharge rate changed in 13 % of cells, and the position changed in 30 % of cells during walking at various speed.9. The inactivation or extirpation of the MC did not hamper the performance of the tasks described above,10. It can be concluded that the motor cortex is not necessary for adaptation of locomotion to various loadings, but the motor cortex receives information on changes in movement power during current locomotor movements, which may be used for correction of locomotion in a new task.