Functional difference and relationship between cerebrum and cerebellum for bimanual coordination

本研究项目的目的是揭示大脑和小脑是如何共享和关联执行双手协调的功能的。对人类参与者进行的两项功能磁共振研究显示，大脑运动相关区域和小脑运动相关区域都显示出反映运动时间模式的活动模式，并且所有区域都明显被激活，以便进行双手协调。用手腕关节执行步态跟踪任务的猴小脑神经元的细胞外记录显示，在上肢运动过程中，小脑通过苔藓纤维接受与初级运动皮质和运动前区相同的输入。此外，可以说，小脑输入层加强了输入，将特定的信息传递给浦肯野细胞。小脑深部核团中的神经元对运动执行具有不同的定位功能，即投射的定位。因此，我们认为大脑和小脑在动作执行的不同阶段会产生不同的功能循环，这种控制系统也是以双手协调的方式工作的。

The purpose of this study project was to reveal how the cerebrum and the cerebellum share and correlate functions to perform bimanual coordination. Two fMRI studies of human participants revealed that both the cerebral motor-related areas and the cerebellar motor-related areas exhibited activity patterns which reflect temporal patterns of movements, and that all the areas were clearly activated for bimanual coordination. The extracellular recording of cerebellar neuron of monkey performing a step tracking task with its wrist joint revealed that the cerebellum receives the same input as output of the primary motor cortex and the premotor area via mossy fibers during upper limb movement. Moreover, it is possible to say that the cerebellar input layer sharpen the input to convey specific information to Purkinje cells. The neurons in the deep cerebellar nuclei exhibited different functions for movement execution with location, that is, location of their projection. Therefore, it is suggested that the cerebrum and the cerebellum make several loops of function corresponding to the phases of movement execution, and that such control system also work in bimanual coordination.