The supplementary motor area modulates perturbation-evoked discharges of neurones in the precentral motor cortex.
The hypothesis was tested that the supplementary motor cortex (SMA) may influence the responsiveness of area 4 neurones to kinesthetic stimuli. In the awake monkey, responses to arm displacements were recorded with and without conditioning intracortical stimulation of the SMA. In 14 of 26 tested area 4 neurones, there was an increase of the response latency and/or a decrease of the response magnitude when the peripheral stimulus was conditioned by SMA stimulation. Field potentials evoked by the displacements were reduced in 3 out of 7 recordings. These findings suggest that the SMA exerts subtle inhibitory effects on the motor cortex or its inputs.
D000818:Animals; D001931:Brain Mapping; D003213:Conditioning, Psychological / Q000502:physiology; D004558:Electric Stimulation; D005071:Evoked Potentials; D000882:Haplorhini; D007699:Kinesthesis / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D011930:Reaction Time / Q000502:physiology