Contributions of the motor cortex and the cerebellum to a simple learned movement in the monkey.
Monkeys were trained to perform isometric plantar flexions of the foot in a simple reaction time situation. In test sessions, the contralateral hindlimb area of the motor cortex was cooled by a cryode placed on the dura until somatosensory evoked potentials disappeared. Movement amplitude decreased to about 70% of initial size; reaction time which was measured on the EMG, and torque signals increased slightly; and the evoked response in the dentate nucleus of the cerebellum remained unchanged. An extensive lesion in the motor cortex by coagulation reduced the movement amplitude to 10% of its preoperational size, but again, did not change reaction time significantly. It is concluded that the motor cortex is not essential for the execution of this overtrained simple movement.
D000818:Animals; D001931:Brain Mapping; D002529:Cerebellar Nuclei / Q000502:physiology*; D004576:Electromyography; D008252:Macaca fascicularis; D009043:Motor Activity / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement; D009434:Neural Pathways / Q000502:physiology; D011930:Reaction Time / Q000502:physiology