Contributions of the motor cortex and the cerebellum to a simple learned movement in the monkey

• Published in: Neuroscience letters Vol. 46; no. 2; p. 235
• Main Authors: Rüegg, D G, Juvet, P
• Format: Journal Article
• Language: English
• Published: Ireland 04.05.1984
• Subjects: Animals; Brain Mapping; Cerebellar Nuclei - physiology; Electromyography; Macaca fascicularis; Motor Activity - physiology; Motor Cortex - physiology; Movement; Neural Pathways - physiology; Reaction Time - physiology
• ISSN: 0304-3940
• DOI: 10.1016/0304-3940(84)90448-8

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.