Initiation of voluntary movement and cerebro-cerebellar neuronal circuit

以恒河猴(Macaca Fuscata)为研究对象，研究了猕猴自主活动的启动、控制和学习机制。他们接受了视觉启动的反应时手运动的训练，并用长期植入这些皮质的电极记录和分析与运动相关的大脑皮层和小脑皮质场电位。采用局部降温的方法对大脑皮层不同区域进行降温，观察降温过程中运动电位和皮质场电位的变化。研究结果总结如下：1.运动前的特征场电位分别记录在前额叶、前运动、运动、躯体感觉、纹前、纹状皮质等部位，前额叶，尤其是“弓状前核”的活动增加，运动前皮层似乎与视觉刺激与运动相关的“再认学习”有关。大脑-小脑相互作用的招募是一种…更多的归因于获得“技能学习”，提高反应时移动的时机。来自小脑皮质，特别是小脑半球小腿的慢性记录显示，苔藓纤维反应是在视觉刺激开始后约50ms的潜伏期诱发的。这与前额叶和运动前皮质激活小脑，进而刺激运动皮质执行运动的假设是一致的。发现苔藓纤维反应随着学习过程而增加，这与大脑皮层区域的场电位分析的结果一致。暂时性的前肢运动皮质局部降温导致对侧反应时运动的减弱和缓慢。分析表明，在运动皮层降温过程中，躯体感觉皮层的代偿运动功能有助于运动的执行，尽管运动皮层降温较弱且速度较慢。运动前皮质的局部降温使获得的视觉-运动整合分离，也使反应时更长、更多变。弓状前区降温只引起运动前皮质降温的后一种效应。对前额叶皮质其他区域的高级整合功能进行了研究，得到了启发进一步研究的结果。较少

Mechanisms of initiation, control and learning of voluntary movements were investigated by using monkeys (Macaca fuscata). They were trained with visually-initiated, reaction-time hand movements and field potentials in the cerebral cortex and the cerebellar cortex associated with the movement were recorded and analysed with electrodes chronically implanted in these cortices. Also a local cooling method was applied to different areas of the cerebral cortex, and changes of the movement and cortical field potentials were explored during the cooling. Results will be summarized as below.1. Characteristic field potentials prior to the movement were recorded respectively in the prefrontal, premotor, motor, somatosensory, prestriate, striate cortex etc. Increasing activities of the prefrontal, especially "prearcuate", and the premotor cortices appeared to correlate to "recognition learning" associating the visual stimulus to the movement. Recruitment of the cerebro-cerebellar interaction was a … More ttributed to attaining "skill learning" improving the timing of reaction-time movement.2. Chronic recording from the cerebellar cortex, particularly the crus <II> of the cerebellar hemisphere, revealed that mossy fibre responses are induced at a latency of about 50 ms after the onset of visual stimulus. This is consistent with the assumption that the prefrontal and premotor cortices activate the cerebellum and in turn excite the motor cortex to execute the movement. The mossy fibre response was found to increase in accordance with the learning processes in agreement with the results of field potential analyses in the cerebral cortical areas.3. Temporal local cooling of the forelimb motor cortex resulted in weakness and slowness of the reaction-time movement on the contralateral side. Analyses revealed that the compensatory motor function of the somatosensory cortex contributes to the execution of the movement during the motor cortex cooling although weak and slow.4. Local cooling of the premotor cortex dissociated the aquired visuo-motor integration, and also made reaction times longer and more variable. The prearcuate area cooling induced only the latter effect of the premotor cortex cooling. The higher integrative function of other areas in the prefrontal cortex was investigated and results inspiring further studies were obtained. Less