Dormont J F, Farin D, Schmied A, Amalric M
Laboratoire de Neurobiologie et Neuropharmacologie du Développement, CNRS URA 1121, Université de Paris-Sud, Orsay, France.
Exp Brain Res. 1989;77(2):271-82. doi: 10.1007/BF00274984.
The activity of 98 Red Nucleus neurons was recorded in 3 cats operantly conditioned to perform a ballistic forelimb flexion movement triggered after a brief sound in a simple Reaction Time condition, or Delayed after the same sound in the presence of a tone cue. Fifty-eight task related neurons presented changes of activity in either one or both conditions. Forty-four of them were studied quantitatively and classified in 3 categories: 1) only 16% of the units presented similar changes of firing preceding the triggered or delayed movement; 2) most units (55%) presented different changes of activity in the two conditions: in the Delayed condition, the activation occurred earlier before the movement, and/or the change in magnitude was reduced or the pattern of activity was modified; 3) moreover, for 29% of the units, the change of activity observed before movement in the Reaction Time condition was severely reduced or even absent in the Delayed condition. For some of these neurons a building-up of activity was observed very early in the Reaction Time condition, during the preparatory period, well before the occurrence of the conditioned stimulus. These results show that the Red Nucleus activity preceding a movement is clearly dependent on its initiation conditions. The distinct patterns of unit firing observed in the Reaction Time condition and in the Delayed condition are tentatively related to the different preparation and initiation constraints determined by the behavioral conditions.
在3只猫身上记录了98个红核神经元的活动，这些猫经过操作性条件反射训练，在简单反应时条件下，听到短暂声音后触发弹道式前肢屈曲运动，或者在有音调提示的情况下，在相同声音后延迟触发该运动。58个与任务相关的神经元在一种或两种条件下出现了活动变化。其中44个神经元进行了定量研究，并分为3类：1）只有16%的神经元在触发或延迟运动之前呈现出相似的放电变化；2）大多数神经元（55%）在两种条件下呈现出不同的活动变化：在延迟条件下，激活在运动之前更早发生，和/或幅度变化减小或活动模式改变；3）此外，对于29%的神经元，在反应时条件下运动前观察到的活动变化在延迟条件下严重减少甚至消失。对于其中一些神经元，在反应时条件下，早在准备期，即在条件刺激出现之前很久，就观察到了活动的增强。这些结果表明，运动前的红核活动明显取决于其起始条件。在反应时条件和延迟条件下观察到的不同单位放电模式，初步与行为条件所决定的不同准备和起始限制有关。
