抄録
Monkeys were trained to lift a lever (self-paced hand movement); to open the mouth (self-paced mouth movement); and to protrude the abdomen (self-paced trunk movement), all at self-pace. Cortical field potentials were recorded by electrodes implanted on the surface and at a 2.0-3.0 mm depth in various cerebral cortices in the monkey during self-paced movements. A surface-negative, depth-positive potential (readiness potential) appeared about 1.0 s before onset of every self-paced movement in the premotor, motor, somatosensory and posterior parietal cortices. The readiness potential in the premotor cortex did not show so marked a somatotopical distribution and laterality related to a moving hand as those in the motor, somatosensory and posterior parietal cortices. Monkeys were also tasked to rotate both the neck and trunk to the right or left at self-pace (compound movement), after they were trained for self-paced rotation movement of the neck or trunk (simple movement). Cortical field potential recording was performed during the process of learning the compound movement. At an early learning stage when mainly simple movements were performed, readiness potential was smaller in amplitude in the premotor cortex. As the amplitude of the potential in the cortex became bigger, the compound movements gradually increased in number and skill. Electrical stimulation of the premotor cortex through the recording electrodes induced movements similar to the compound movements. This suggests that the premotor cortex is related to the generation of compound movements. [Jpn J Physiol 54 Suppl:S185 (2004)]
