抄録
To investigate the role of the supplementary motor area (SMA) in bimanual coordination, single neuron activity was recorded from the SMA during the performance of a bilateral hand movement task in combination with symmetric and asymmetric movements. This task enabled us to separately examine neuronal activity related to unimanual vs bimanual or symmetric vs asymmetric movement process. In the present study, two Japanese monkeys were trained to perform the task. Depending on the locations of motor instruction cues, the monkeys had to execute extension and/or flexion wrist movements with either or both hands. All eight combinations were classified into unimanual vs bimanual or symmetric vs asymmetric movements. About half of the SMA neurons recorded were active in response to contralateral movements, while more than 1/3 of them responded to bilateral movements. The activity specific to unimanual or bimanual movements was observed in 12% of SMA neurons. Of these three types of SMA neurons (contralateral, bilateral, movement-specific), 57% exhibited differential activities between the symmetric and asymmetric movements. [Jpn J Physiol 54 Suppl:S185 (2004)]
